clk.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com>
   4 * Copyright (C) 2011-2012 Linaro Ltd <mturquette@linaro.org>
   5 *
   6 * Standard functionality for the common clock API.  See Documentation/driver-api/clk.rst
   7 */
   8
   9#include <linux/clk/clk-conf.h>
  10#include <linux/clkdev.h>
  11#include <linux/clk.h>
  12#include <linux/clk-provider.h>
  13#include <linux/device.h>
  14#include <linux/err.h>
  15#include <linux/hashtable.h>
  16#include <linux/init.h>
  17#include <linux/list.h>
  18#include <linux/module.h>
  19#include <linux/mutex.h>
  20#include <linux/of.h>
  21#include <linux/pm_runtime.h>
  22#include <linux/sched.h>
  23#include <linux/slab.h>
  24#include <linux/spinlock.h>
  25#include <linux/string.h>
  26#include <linux/stringhash.h>
  27
  28#include "clk.h"
  29
  30static DEFINE_SPINLOCK(enable_lock);
  31static DEFINE_MUTEX(prepare_lock);
  32
  33static struct task_struct *prepare_owner;
  34static struct task_struct *enable_owner;
  35
  36static int prepare_refcnt;
  37static int enable_refcnt;
  38
  39#define CLK_HASH_BITS 9
  40static DEFINE_HASHTABLE(clk_hashtable, CLK_HASH_BITS);
  41
  42static HLIST_HEAD(clk_root_list);
  43static HLIST_HEAD(clk_orphan_list);
  44static LIST_HEAD(clk_notifier_list);
  45
  46/* List of registered clks that use runtime PM */
  47static HLIST_HEAD(clk_rpm_list);
  48static DEFINE_MUTEX(clk_rpm_list_lock);
  49
  50static const struct hlist_head *all_lists[] = {
  51	&clk_root_list,
  52	&clk_orphan_list,
  53	NULL,
  54};
  55
  56/***    private data structures    ***/
  57
  58struct clk_parent_map {
  59	const struct clk_hw	*hw;
  60	struct clk_core		*core;
  61	const char		*fw_name;
  62	const char		*name;
  63	int			index;
  64};
  65
  66struct clk_core {
  67	const char		*name;
  68	const struct clk_ops	*ops;
  69	struct clk_hw		*hw;
  70	struct module		*owner;
  71	struct device		*dev;
  72	struct hlist_node	rpm_node;
  73	struct device_node	*of_node;
  74	struct clk_core		*parent;
  75	struct clk_parent_map	*parents;
  76	u8			num_parents;
  77	u8			new_parent_index;
  78	unsigned long		rate;
  79	unsigned long		req_rate;
  80	unsigned long		new_rate;
  81	struct clk_core		*new_parent;
  82	struct clk_core		*new_child;
  83	unsigned long		flags;
  84	bool			orphan;
  85	bool			rpm_enabled;
  86	unsigned int		enable_count;
  87	unsigned int		prepare_count;
  88	unsigned int		protect_count;
  89	unsigned long		min_rate;
  90	unsigned long		max_rate;
  91	unsigned long		accuracy;
  92	int			phase;
  93	struct clk_duty		duty;
  94	struct hlist_head	children;
  95	struct hlist_node	child_node;
  96	struct hlist_node	hashtable_node;
  97	struct hlist_head	clks;
  98	unsigned int		notifier_count;
  99#ifdef CONFIG_DEBUG_FS
 100	struct dentry		*dentry;
 101	struct hlist_node	debug_node;
 102#endif
 103	struct kref		ref;
 104};
 105
 106#define CREATE_TRACE_POINTS
 107#include <trace/events/clk.h>
 108
 109struct clk {
 110	struct clk_core	*core;
 111	struct device *dev;
 112	const char *dev_id;
 113	const char *con_id;
 114	unsigned long min_rate;
 115	unsigned long max_rate;
 116	unsigned int exclusive_count;
 117	struct hlist_node clks_node;
 118};
 119
 120/***           runtime pm          ***/
 121static int clk_pm_runtime_get(struct clk_core *core)
 122{
 123	if (!core->rpm_enabled)
 124		return 0;
 125
 126	return pm_runtime_resume_and_get(core->dev);
 127}
 128
 129static void clk_pm_runtime_put(struct clk_core *core)
 130{
 131	if (!core->rpm_enabled)
 132		return;
 133
 134	pm_runtime_put_sync(core->dev);
 135}
 136
 137/**
 138 * clk_pm_runtime_get_all() - Runtime "get" all clk provider devices
 139 *
 140 * Call clk_pm_runtime_get() on all runtime PM enabled clks in the clk tree so
 141 * that disabling unused clks avoids a deadlock where a device is runtime PM
 142 * resuming/suspending and the runtime PM callback is trying to grab the
 143 * prepare_lock for something like clk_prepare_enable() while
 144 * clk_disable_unused_subtree() holds the prepare_lock and is trying to runtime
 145 * PM resume/suspend the device as well.
 146 *
 147 * Context: Acquires the 'clk_rpm_list_lock' and returns with the lock held on
 148 * success. Otherwise the lock is released on failure.
 149 *
 150 * Return: 0 on success, negative errno otherwise.
 151 */
 152static int clk_pm_runtime_get_all(void)
 153{
 154	int ret;
 155	struct clk_core *core, *failed;
 156
 157	/*
 158	 * Grab the list lock to prevent any new clks from being registered
 159	 * or unregistered until clk_pm_runtime_put_all().
 160	 */
 161	mutex_lock(&clk_rpm_list_lock);
 162
 163	/*
 164	 * Runtime PM "get" all the devices that are needed for the clks
 165	 * currently registered. Do this without holding the prepare_lock, to
 166	 * avoid the deadlock.
 167	 */
 168	hlist_for_each_entry(core, &clk_rpm_list, rpm_node) {
 169		ret = clk_pm_runtime_get(core);
 170		if (ret) {
 171			failed = core;
 172			pr_err("clk: Failed to runtime PM get '%s' for clk '%s'\n",
 173			       dev_name(failed->dev), failed->name);
 174			goto err;
 175		}
 176	}
 177
 178	return 0;
 179
 180err:
 181	hlist_for_each_entry(core, &clk_rpm_list, rpm_node) {
 182		if (core == failed)
 183			break;
 184
 185		clk_pm_runtime_put(core);
 186	}
 187	mutex_unlock(&clk_rpm_list_lock);
 188
 189	return ret;
 190}
 191
 192/**
 193 * clk_pm_runtime_put_all() - Runtime "put" all clk provider devices
 194 *
 195 * Put the runtime PM references taken in clk_pm_runtime_get_all() and release
 196 * the 'clk_rpm_list_lock'.
 197 */
 198static void clk_pm_runtime_put_all(void)
 199{
 200	struct clk_core *core;
 201
 202	hlist_for_each_entry(core, &clk_rpm_list, rpm_node)
 203		clk_pm_runtime_put(core);
 204	mutex_unlock(&clk_rpm_list_lock);
 205}
 206
 207static void clk_pm_runtime_init(struct clk_core *core)
 208{
 209	struct device *dev = core->dev;
 210
 211	if (dev && pm_runtime_enabled(dev)) {
 212		core->rpm_enabled = true;
 213
 214		mutex_lock(&clk_rpm_list_lock);
 215		hlist_add_head(&core->rpm_node, &clk_rpm_list);
 216		mutex_unlock(&clk_rpm_list_lock);
 217	}
 218}
 219
 220/***           locking             ***/
 221static void clk_prepare_lock(void)
 222{
 223	if (!mutex_trylock(&prepare_lock)) {
 224		if (prepare_owner == current) {
 225			prepare_refcnt++;
 226			return;
 227		}
 228		mutex_lock(&prepare_lock);
 229	}
 230	WARN_ON_ONCE(prepare_owner != NULL);
 231	WARN_ON_ONCE(prepare_refcnt != 0);
 232	prepare_owner = current;
 233	prepare_refcnt = 1;
 234}
 235
 236static void clk_prepare_unlock(void)
 237{
 238	WARN_ON_ONCE(prepare_owner != current);
 239	WARN_ON_ONCE(prepare_refcnt == 0);
 240
 241	if (--prepare_refcnt)
 242		return;
 243	prepare_owner = NULL;
 244	mutex_unlock(&prepare_lock);
 245}
 246
 247static unsigned long clk_enable_lock(void)
 248	__acquires(enable_lock)
 249{
 250	unsigned long flags;
 251
 252	/*
 253	 * On UP systems, spin_trylock_irqsave() always returns true, even if
 254	 * we already hold the lock. So, in that case, we rely only on
 255	 * reference counting.
 256	 */
 257	if (!IS_ENABLED(CONFIG_SMP) ||
 258	    !spin_trylock_irqsave(&enable_lock, flags)) {
 259		if (enable_owner == current) {
 260			enable_refcnt++;
 261			__acquire(enable_lock);
 262			if (!IS_ENABLED(CONFIG_SMP))
 263				local_save_flags(flags);
 264			return flags;
 265		}
 266		spin_lock_irqsave(&enable_lock, flags);
 267	}
 268	WARN_ON_ONCE(enable_owner != NULL);
 269	WARN_ON_ONCE(enable_refcnt != 0);
 270	enable_owner = current;
 271	enable_refcnt = 1;
 272	return flags;
 273}
 274
 275static void clk_enable_unlock(unsigned long flags)
 276	__releases(enable_lock)
 277{
 278	WARN_ON_ONCE(enable_owner != current);
 279	WARN_ON_ONCE(enable_refcnt == 0);
 280
 281	if (--enable_refcnt) {
 282		__release(enable_lock);
 283		return;
 284	}
 285	enable_owner = NULL;
 286	spin_unlock_irqrestore(&enable_lock, flags);
 287}
 288
 289static bool clk_core_rate_is_protected(struct clk_core *core)
 290{
 291	return core->protect_count;
 292}
 293
 294static bool clk_core_is_prepared(struct clk_core *core)
 295{
 296	bool ret = false;
 297
 298	/*
 299	 * .is_prepared is optional for clocks that can prepare
 300	 * fall back to software usage counter if it is missing
 301	 */
 302	if (!core->ops->is_prepared)
 303		return core->prepare_count;
 304
 305	if (!clk_pm_runtime_get(core)) {
 306		ret = core->ops->is_prepared(core->hw);
 307		clk_pm_runtime_put(core);
 308	}
 309
 310	return ret;
 311}
 312
 313static bool clk_core_is_enabled(struct clk_core *core)
 314{
 315	bool ret = false;
 316
 317	/*
 318	 * .is_enabled is only mandatory for clocks that gate
 319	 * fall back to software usage counter if .is_enabled is missing
 320	 */
 321	if (!core->ops->is_enabled)
 322		return core->enable_count;
 323
 324	/*
 325	 * Check if clock controller's device is runtime active before
 326	 * calling .is_enabled callback. If not, assume that clock is
 327	 * disabled, because we might be called from atomic context, from
 328	 * which pm_runtime_get() is not allowed.
 329	 * This function is called mainly from clk_disable_unused_subtree,
 330	 * which ensures proper runtime pm activation of controller before
 331	 * taking enable spinlock, but the below check is needed if one tries
 332	 * to call it from other places.
 333	 */
 334	if (core->rpm_enabled) {
 335		pm_runtime_get_noresume(core->dev);
 336		if (!pm_runtime_active(core->dev)) {
 337			ret = false;
 338			goto done;
 339		}
 340	}
 341
 342	/*
 343	 * This could be called with the enable lock held, or from atomic
 344	 * context. If the parent isn't enabled already, we can't do
 345	 * anything here. We can also assume this clock isn't enabled.
 346	 */
 347	if ((core->flags & CLK_OPS_PARENT_ENABLE) && core->parent)
 348		if (!clk_core_is_enabled(core->parent)) {
 349			ret = false;
 350			goto done;
 351		}
 352
 353	ret = core->ops->is_enabled(core->hw);
 354done:
 355	if (core->rpm_enabled)
 356		pm_runtime_put(core->dev);
 357
 358	return ret;
 359}
 360
 361/***    helper functions   ***/
 362
 363const char *__clk_get_name(const struct clk *clk)
 364{
 365	return !clk ? NULL : clk->core->name;
 366}
 367EXPORT_SYMBOL_GPL(__clk_get_name);
 368
 369const char *clk_hw_get_name(const struct clk_hw *hw)
 370{
 371	return hw->core->name;
 372}
 373EXPORT_SYMBOL_GPL(clk_hw_get_name);
 374
 375struct device *clk_hw_get_dev(const struct clk_hw *hw)
 376{
 377	return hw->core->dev;
 378}
 379EXPORT_SYMBOL_GPL(clk_hw_get_dev);
 380
 381struct device_node *clk_hw_get_of_node(const struct clk_hw *hw)
 382{
 383	return hw->core->of_node;
 384}
 385EXPORT_SYMBOL_GPL(clk_hw_get_of_node);
 386
 387struct clk_hw *__clk_get_hw(struct clk *clk)
 388{
 389	return !clk ? NULL : clk->core->hw;
 390}
 391EXPORT_SYMBOL_GPL(__clk_get_hw);
 392
 393unsigned int clk_hw_get_num_parents(const struct clk_hw *hw)
 394{
 395	return hw->core->num_parents;
 396}
 397EXPORT_SYMBOL_GPL(clk_hw_get_num_parents);
 398
 399struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw)
 400{
 401	return hw->core->parent ? hw->core->parent->hw : NULL;
 402}
 403EXPORT_SYMBOL_GPL(clk_hw_get_parent);
 404
 405static struct clk_core *clk_core_lookup(const char *name)
 406{
 407	struct clk_core *core;
 408	u32 hash;
 409
 410	if (!name)
 411		return NULL;
 412
 413	hash = full_name_hash(NULL, name, strlen(name));
 414
 415	/* search the hashtable */
 416	hash_for_each_possible(clk_hashtable, core, hashtable_node, hash)
 417		if (!strcmp(core->name, name))
 418			return core;
 419
 420	return NULL;
 421}
 422
 423#ifdef CONFIG_OF
 424static int of_parse_clkspec(const struct device_node *np, int index,
 425			    const char *name, struct of_phandle_args *out_args);
 426static struct clk_hw *
 427of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec);
 428#else
 429static inline int of_parse_clkspec(const struct device_node *np, int index,
 430				   const char *name,
 431				   struct of_phandle_args *out_args)
 432{
 433	return -ENOENT;
 434}
 435static inline struct clk_hw *
 436of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
 437{
 438	return ERR_PTR(-ENOENT);
 439}
 440#endif
 441
 442/**
 443 * clk_core_get - Find the clk_core parent of a clk
 444 * @core: clk to find parent of
 445 * @p_index: parent index to search for
 446 *
 447 * This is the preferred method for clk providers to find the parent of a
 448 * clk when that parent is external to the clk controller. The parent_names
 449 * array is indexed and treated as a local name matching a string in the device
 450 * node's 'clock-names' property or as the 'con_id' matching the device's
 451 * dev_name() in a clk_lookup. This allows clk providers to use their own
 452 * namespace instead of looking for a globally unique parent string.
 453 *
 454 * For example the following DT snippet would allow a clock registered by the
 455 * clock-controller@c001 that has a clk_init_data::parent_data array
 456 * with 'xtal' in the 'name' member to find the clock provided by the
 457 * clock-controller@f00abcd without needing to get the globally unique name of
 458 * the xtal clk.
 459 *
 460 *      parent: clock-controller@f00abcd {
 461 *              reg = <0xf00abcd 0xabcd>;
 462 *              #clock-cells = <0>;
 463 *      };
 464 *
 465 *      clock-controller@c001 {
 466 *              reg = <0xc001 0xf00d>;
 467 *              clocks = <&parent>;
 468 *              clock-names = "xtal";
 469 *              #clock-cells = <1>;
 470 *      };
 471 *
 472 * Returns: -ENOENT when the provider can't be found or the clk doesn't
 473 * exist in the provider or the name can't be found in the DT node or
 474 * in a clkdev lookup. NULL when the provider knows about the clk but it
 475 * isn't provided on this system.
 476 * A valid clk_core pointer when the clk can be found in the provider.
 477 */
 478static struct clk_core *clk_core_get(struct clk_core *core, u8 p_index)
 479{
 480	const char *name = core->parents[p_index].fw_name;
 481	int index = core->parents[p_index].index;
 482	struct clk_hw *hw = ERR_PTR(-ENOENT);
 483	struct device *dev = core->dev;
 484	const char *dev_id = dev ? dev_name(dev) : NULL;
 485	struct device_node *np = core->of_node;
 486	struct of_phandle_args clkspec;
 487
 488	if (np && (name || index >= 0) &&
 489	    !of_parse_clkspec(np, index, name, &clkspec)) {
 490		hw = of_clk_get_hw_from_clkspec(&clkspec);
 491		of_node_put(clkspec.np);
 492	} else if (name) {
 493		/*
 494		 * If the DT search above couldn't find the provider fallback to
 495		 * looking up via clkdev based clk_lookups.
 496		 */
 497		hw = clk_find_hw(dev_id, name);
 498	}
 499
 500	if (IS_ERR(hw))
 501		return ERR_CAST(hw);
 502
 503	if (!hw)
 504		return NULL;
 505
 506	return hw->core;
 507}
 508
 509static void clk_core_fill_parent_index(struct clk_core *core, u8 index)
 510{
 511	struct clk_parent_map *entry = &core->parents[index];
 512	struct clk_core *parent;
 513
 514	if (entry->hw) {
 515		parent = entry->hw->core;
 516	} else {
 517		parent = clk_core_get(core, index);
 518		if (PTR_ERR(parent) == -ENOENT && entry->name)
 519			parent = clk_core_lookup(entry->name);
 520	}
 521
 522	/*
 523	 * We have a direct reference but it isn't registered yet?
 524	 * Orphan it and let clk_reparent() update the orphan status
 525	 * when the parent is registered.
 526	 */
 527	if (!parent)
 528		parent = ERR_PTR(-EPROBE_DEFER);
 529
 530	/* Only cache it if it's not an error */
 531	if (!IS_ERR(parent))
 532		entry->core = parent;
 533}
 534
 535static struct clk_core *clk_core_get_parent_by_index(struct clk_core *core,
 536							 u8 index)
 537{
 538	if (!core || index >= core->num_parents || !core->parents)
 539		return NULL;
 540
 541	if (!core->parents[index].core)
 542		clk_core_fill_parent_index(core, index);
 543
 544	return core->parents[index].core;
 545}
 546
 547struct clk_hw *
 548clk_hw_get_parent_by_index(const struct clk_hw *hw, unsigned int index)
 549{
 550	struct clk_core *parent;
 551
 552	parent = clk_core_get_parent_by_index(hw->core, index);
 553
 554	return !parent ? NULL : parent->hw;
 555}
 556EXPORT_SYMBOL_GPL(clk_hw_get_parent_by_index);
 557
 558unsigned int __clk_get_enable_count(struct clk *clk)
 559{
 560	return !clk ? 0 : clk->core->enable_count;
 561}
 562
 563static unsigned long clk_core_get_rate_nolock(struct clk_core *core)
 564{
 565	if (!core)
 566		return 0;
 567
 568	if (!core->num_parents || core->parent)
 569		return core->rate;
 570
 571	/*
 572	 * Clk must have a parent because num_parents > 0 but the parent isn't
 573	 * known yet. Best to return 0 as the rate of this clk until we can
 574	 * properly recalc the rate based on the parent's rate.
 575	 */
 576	return 0;
 577}
 578
 579unsigned long clk_hw_get_rate(const struct clk_hw *hw)
 580{
 581	return clk_core_get_rate_nolock(hw->core);
 582}
 583EXPORT_SYMBOL_GPL(clk_hw_get_rate);
 584
 585static unsigned long clk_core_get_accuracy_no_lock(struct clk_core *core)
 586{
 587	if (!core)
 588		return 0;
 589
 590	return core->accuracy;
 591}
 592
 593unsigned long clk_hw_get_flags(const struct clk_hw *hw)
 594{
 595	return hw->core->flags;
 596}
 597EXPORT_SYMBOL_GPL(clk_hw_get_flags);
 598
 599bool clk_hw_is_prepared(const struct clk_hw *hw)
 600{
 601	return clk_core_is_prepared(hw->core);
 602}
 603EXPORT_SYMBOL_GPL(clk_hw_is_prepared);
 604
 605bool clk_hw_is_enabled(const struct clk_hw *hw)
 606{
 607	return clk_core_is_enabled(hw->core);
 608}
 609EXPORT_SYMBOL_GPL(clk_hw_is_enabled);
 610
 611bool __clk_is_enabled(struct clk *clk)
 612{
 613	if (!clk)
 614		return false;
 615
 616	return clk_core_is_enabled(clk->core);
 617}
 618EXPORT_SYMBOL_GPL(__clk_is_enabled);
 619
 620static bool mux_is_better_rate(unsigned long rate, unsigned long now,
 621			   unsigned long best, unsigned long flags)
 622{
 623	if (flags & CLK_MUX_ROUND_CLOSEST)
 624		return abs(now - rate) < abs(best - rate);
 625
 626	return now <= rate && now > best;
 627}
 628
 629static void clk_core_init_rate_req(struct clk_core * const core,
 630				   struct clk_rate_request *req,
 631				   unsigned long rate);
 632
 633static int clk_core_round_rate_nolock(struct clk_core *core,
 634				      struct clk_rate_request *req);
 635
 636static bool clk_core_has_parent(struct clk_core *core, const struct clk_core *parent)
 637{
 638	struct clk_core *tmp;
 639	unsigned int i;
 640
 641	/* Optimize for the case where the parent is already the parent. */
 642	if (core->parent == parent)
 643		return true;
 644
 645	for (i = 0; i < core->num_parents; i++) {
 646		tmp = clk_core_get_parent_by_index(core, i);
 647		if (!tmp)
 648			continue;
 649
 650		if (tmp == parent)
 651			return true;
 652	}
 653
 654	return false;
 655}
 656
 657static void
 658clk_core_forward_rate_req(struct clk_core *core,
 659			  const struct clk_rate_request *old_req,
 660			  struct clk_core *parent,
 661			  struct clk_rate_request *req,
 662			  unsigned long parent_rate)
 663{
 664	if (WARN_ON(!clk_core_has_parent(core, parent)))
 665		return;
 666
 667	clk_core_init_rate_req(parent, req, parent_rate);
 668
 669	if (req->min_rate < old_req->min_rate)
 670		req->min_rate = old_req->min_rate;
 671
 672	if (req->max_rate > old_req->max_rate)
 673		req->max_rate = old_req->max_rate;
 674}
 675
 676static int
 677clk_core_determine_rate_no_reparent(struct clk_hw *hw,
 678				    struct clk_rate_request *req)
 679{
 680	struct clk_core *core = hw->core;
 681	struct clk_core *parent = core->parent;
 682	unsigned long best;
 683	int ret;
 684
 685	if (core->flags & CLK_SET_RATE_PARENT) {
 686		struct clk_rate_request parent_req;
 687
 688		if (!parent) {
 689			req->rate = 0;
 690			return 0;
 691		}
 692
 693		clk_core_forward_rate_req(core, req, parent, &parent_req,
 694					  req->rate);
 695
 696		trace_clk_rate_request_start(&parent_req);
 697
 698		ret = clk_core_round_rate_nolock(parent, &parent_req);
 699		if (ret)
 700			return ret;
 701
 702		trace_clk_rate_request_done(&parent_req);
 703
 704		best = parent_req.rate;
 705	} else if (parent) {
 706		best = clk_core_get_rate_nolock(parent);
 707	} else {
 708		best = clk_core_get_rate_nolock(core);
 709	}
 710
 711	req->best_parent_rate = best;
 712	req->rate = best;
 713
 714	return 0;
 715}
 716
 717int clk_mux_determine_rate_flags(struct clk_hw *hw,
 718				 struct clk_rate_request *req,
 719				 unsigned long flags)
 720{
 721	struct clk_core *core = hw->core, *parent, *best_parent = NULL;
 722	int i, num_parents, ret;
 723	unsigned long best = 0;
 724
 725	/* if NO_REPARENT flag set, pass through to current parent */
 726	if (core->flags & CLK_SET_RATE_NO_REPARENT)
 727		return clk_core_determine_rate_no_reparent(hw, req);
 728
 729	/* find the parent that can provide the fastest rate <= rate */
 730	num_parents = core->num_parents;
 731	for (i = 0; i < num_parents; i++) {
 732		unsigned long parent_rate;
 733
 734		parent = clk_core_get_parent_by_index(core, i);
 735		if (!parent)
 736			continue;
 737
 738		if (core->flags & CLK_SET_RATE_PARENT) {
 739			struct clk_rate_request parent_req;
 740
 741			clk_core_forward_rate_req(core, req, parent, &parent_req, req->rate);
 742
 743			trace_clk_rate_request_start(&parent_req);
 744
 745			ret = clk_core_round_rate_nolock(parent, &parent_req);
 746			if (ret)
 747				continue;
 748
 749			trace_clk_rate_request_done(&parent_req);
 750
 751			parent_rate = parent_req.rate;
 752		} else {
 753			parent_rate = clk_core_get_rate_nolock(parent);
 754		}
 755
 756		if (mux_is_better_rate(req->rate, parent_rate,
 757				       best, flags)) {
 758			best_parent = parent;
 759			best = parent_rate;
 760		}
 761	}
 762
 763	if (!best_parent)
 764		return -EINVAL;
 765
 766	req->best_parent_hw = best_parent->hw;
 767	req->best_parent_rate = best;
 768	req->rate = best;
 769
 770	return 0;
 771}
 772EXPORT_SYMBOL_GPL(clk_mux_determine_rate_flags);
 773
 774struct clk *__clk_lookup(const char *name)
 775{
 776	struct clk_core *core = clk_core_lookup(name);
 777
 778	return !core ? NULL : core->hw->clk;
 779}
 780
 781static void clk_core_get_boundaries(struct clk_core *core,
 782				    unsigned long *min_rate,
 783				    unsigned long *max_rate)
 784{
 785	struct clk *clk_user;
 786
 787	lockdep_assert_held(&prepare_lock);
 788
 789	*min_rate = core->min_rate;
 790	*max_rate = core->max_rate;
 791
 792	hlist_for_each_entry(clk_user, &core->clks, clks_node)
 793		*min_rate = max(*min_rate, clk_user->min_rate);
 794
 795	hlist_for_each_entry(clk_user, &core->clks, clks_node)
 796		*max_rate = min(*max_rate, clk_user->max_rate);
 797}
 798
 799/*
 800 * clk_hw_get_rate_range() - returns the clock rate range for a hw clk
 801 * @hw: the hw clk we want to get the range from
 802 * @min_rate: pointer to the variable that will hold the minimum
 803 * @max_rate: pointer to the variable that will hold the maximum
 804 *
 805 * Fills the @min_rate and @max_rate variables with the minimum and
 806 * maximum that clock can reach.
 807 */
 808void clk_hw_get_rate_range(struct clk_hw *hw, unsigned long *min_rate,
 809			   unsigned long *max_rate)
 810{
 811	clk_core_get_boundaries(hw->core, min_rate, max_rate);
 812}
 813EXPORT_SYMBOL_GPL(clk_hw_get_rate_range);
 814
 815static bool clk_core_check_boundaries(struct clk_core *core,
 816				      unsigned long min_rate,
 817				      unsigned long max_rate)
 818{
 819	struct clk *user;
 820
 821	lockdep_assert_held(&prepare_lock);
 822
 823	if (min_rate > core->max_rate || max_rate < core->min_rate)
 824		return false;
 825
 826	hlist_for_each_entry(user, &core->clks, clks_node)
 827		if (min_rate > user->max_rate || max_rate < user->min_rate)
 828			return false;
 829
 830	return true;
 831}
 832
 833void clk_hw_set_rate_range(struct clk_hw *hw, unsigned long min_rate,
 834			   unsigned long max_rate)
 835{
 836	hw->core->min_rate = min_rate;
 837	hw->core->max_rate = max_rate;
 838}
 839EXPORT_SYMBOL_GPL(clk_hw_set_rate_range);
 840
 841/*
 842 * __clk_mux_determine_rate - clk_ops::determine_rate implementation for a mux type clk
 843 * @hw: mux type clk to determine rate on
 844 * @req: rate request, also used to return preferred parent and frequencies
 845 *
 846 * Helper for finding best parent to provide a given frequency. This can be used
 847 * directly as a determine_rate callback (e.g. for a mux), or from a more
 848 * complex clock that may combine a mux with other operations.
 849 *
 850 * Returns: 0 on success, -EERROR value on error
 851 */
 852int __clk_mux_determine_rate(struct clk_hw *hw,
 853			     struct clk_rate_request *req)
 854{
 855	return clk_mux_determine_rate_flags(hw, req, 0);
 856}
 857EXPORT_SYMBOL_GPL(__clk_mux_determine_rate);
 858
 859int __clk_mux_determine_rate_closest(struct clk_hw *hw,
 860				     struct clk_rate_request *req)
 861{
 862	return clk_mux_determine_rate_flags(hw, req, CLK_MUX_ROUND_CLOSEST);
 863}
 864EXPORT_SYMBOL_GPL(__clk_mux_determine_rate_closest);
 865
 866/*
 867 * clk_hw_determine_rate_no_reparent - clk_ops::determine_rate implementation for a clk that doesn't reparent
 868 * @hw: mux type clk to determine rate on
 869 * @req: rate request, also used to return preferred frequency
 870 *
 871 * Helper for finding best parent rate to provide a given frequency.
 872 * This can be used directly as a determine_rate callback (e.g. for a
 873 * mux), or from a more complex clock that may combine a mux with other
 874 * operations.
 875 *
 876 * Returns: 0 on success, -EERROR value on error
 877 */
 878int clk_hw_determine_rate_no_reparent(struct clk_hw *hw,
 879				      struct clk_rate_request *req)
 880{
 881	return clk_core_determine_rate_no_reparent(hw, req);
 882}
 883EXPORT_SYMBOL_GPL(clk_hw_determine_rate_no_reparent);
 884
 885/***        clk api        ***/
 886
 887static void clk_core_rate_unprotect(struct clk_core *core)
 888{
 889	lockdep_assert_held(&prepare_lock);
 890
 891	if (!core)
 892		return;
 893
 894	if (WARN(core->protect_count == 0,
 895	    "%s already unprotected\n", core->name))
 896		return;
 897
 898	if (--core->protect_count > 0)
 899		return;
 900
 901	clk_core_rate_unprotect(core->parent);
 902}
 903
 904static int clk_core_rate_nuke_protect(struct clk_core *core)
 905{
 906	int ret;
 907
 908	lockdep_assert_held(&prepare_lock);
 909
 910	if (!core)
 911		return -EINVAL;
 912
 913	if (core->protect_count == 0)
 914		return 0;
 915
 916	ret = core->protect_count;
 917	core->protect_count = 1;
 918	clk_core_rate_unprotect(core);
 919
 920	return ret;
 921}
 922
 923/**
 924 * clk_rate_exclusive_put - release exclusivity over clock rate control
 925 * @clk: the clk over which the exclusivity is released
 926 *
 927 * clk_rate_exclusive_put() completes a critical section during which a clock
 928 * consumer cannot tolerate any other consumer making any operation on the
 929 * clock which could result in a rate change or rate glitch. Exclusive clocks
 930 * cannot have their rate changed, either directly or indirectly due to changes
 931 * further up the parent chain of clocks. As a result, clocks up parent chain
 932 * also get under exclusive control of the calling consumer.
 933 *
 934 * If exlusivity is claimed more than once on clock, even by the same consumer,
 935 * the rate effectively gets locked as exclusivity can't be preempted.
 936 *
 937 * Calls to clk_rate_exclusive_put() must be balanced with calls to
 938 * clk_rate_exclusive_get(). Calls to this function may sleep, and do not return
 939 * error status.
 940 */
 941void clk_rate_exclusive_put(struct clk *clk)
 942{
 943	if (!clk)
 944		return;
 945
 946	clk_prepare_lock();
 947
 948	/*
 949	 * if there is something wrong with this consumer protect count, stop
 950	 * here before messing with the provider
 951	 */
 952	if (WARN_ON(clk->exclusive_count <= 0))
 953		goto out;
 954
 955	clk_core_rate_unprotect(clk->core);
 956	clk->exclusive_count--;
 957out:
 958	clk_prepare_unlock();
 959}
 960EXPORT_SYMBOL_GPL(clk_rate_exclusive_put);
 961
 962static void clk_core_rate_protect(struct clk_core *core)
 963{
 964	lockdep_assert_held(&prepare_lock);
 965
 966	if (!core)
 967		return;
 968
 969	if (core->protect_count == 0)
 970		clk_core_rate_protect(core->parent);
 971
 972	core->protect_count++;
 973}
 974
 975static void clk_core_rate_restore_protect(struct clk_core *core, int count)
 976{
 977	lockdep_assert_held(&prepare_lock);
 978
 979	if (!core)
 980		return;
 981
 982	if (count == 0)
 983		return;
 984
 985	clk_core_rate_protect(core);
 986	core->protect_count = count;
 987}
 988
 989/**
 990 * clk_rate_exclusive_get - get exclusivity over the clk rate control
 991 * @clk: the clk over which the exclusity of rate control is requested
 992 *
 993 * clk_rate_exclusive_get() begins a critical section during which a clock
 994 * consumer cannot tolerate any other consumer making any operation on the
 995 * clock which could result in a rate change or rate glitch. Exclusive clocks
 996 * cannot have their rate changed, either directly or indirectly due to changes
 997 * further up the parent chain of clocks. As a result, clocks up parent chain
 998 * also get under exclusive control of the calling consumer.
 999 *
1000 * If exlusivity is claimed more than once on clock, even by the same consumer,
1001 * the rate effectively gets locked as exclusivity can't be preempted.
1002 *
1003 * Calls to clk_rate_exclusive_get() should be balanced with calls to
1004 * clk_rate_exclusive_put(). Calls to this function may sleep.
1005 * Returns 0 on success, -EERROR otherwise
1006 */
1007int clk_rate_exclusive_get(struct clk *clk)
1008{
1009	if (!clk)
1010		return 0;
1011
1012	clk_prepare_lock();
1013	clk_core_rate_protect(clk->core);
1014	clk->exclusive_count++;
1015	clk_prepare_unlock();
1016
1017	return 0;
1018}
1019EXPORT_SYMBOL_GPL(clk_rate_exclusive_get);
1020
1021static void devm_clk_rate_exclusive_put(void *data)
1022{
1023	struct clk *clk = data;
1024
1025	clk_rate_exclusive_put(clk);
1026}
1027
1028int devm_clk_rate_exclusive_get(struct device *dev, struct clk *clk)
1029{
1030	int ret;
1031
1032	ret = clk_rate_exclusive_get(clk);
1033	if (ret)
1034		return ret;
1035
1036	return devm_add_action_or_reset(dev, devm_clk_rate_exclusive_put, clk);
1037}
1038EXPORT_SYMBOL_GPL(devm_clk_rate_exclusive_get);
1039
1040static void clk_core_unprepare(struct clk_core *core)
1041{
1042	lockdep_assert_held(&prepare_lock);
1043
1044	if (!core)
1045		return;
1046
1047	if (WARN(core->prepare_count == 0,
1048	    "%s already unprepared\n", core->name))
1049		return;
1050
1051	if (WARN(core->prepare_count == 1 && core->flags & CLK_IS_CRITICAL,
1052	    "Unpreparing critical %s\n", core->name))
1053		return;
1054
1055	if (core->flags & CLK_SET_RATE_GATE)
1056		clk_core_rate_unprotect(core);
1057
1058	if (--core->prepare_count > 0)
1059		return;
1060
1061	WARN(core->enable_count > 0, "Unpreparing enabled %s\n", core->name);
1062
1063	trace_clk_unprepare(core);
1064
1065	if (core->ops->unprepare)
1066		core->ops->unprepare(core->hw);
1067
1068	trace_clk_unprepare_complete(core);
1069	clk_core_unprepare(core->parent);
1070	clk_pm_runtime_put(core);
1071}
1072
1073static void clk_core_unprepare_lock(struct clk_core *core)
1074{
1075	clk_prepare_lock();
1076	clk_core_unprepare(core);
1077	clk_prepare_unlock();
1078}
1079
1080/**
1081 * clk_unprepare - undo preparation of a clock source
1082 * @clk: the clk being unprepared
1083 *
1084 * clk_unprepare may sleep, which differentiates it from clk_disable.  In a
1085 * simple case, clk_unprepare can be used instead of clk_disable to gate a clk
1086 * if the operation may sleep.  One example is a clk which is accessed over
1087 * I2c.  In the complex case a clk gate operation may require a fast and a slow
1088 * part.  It is this reason that clk_unprepare and clk_disable are not mutually
1089 * exclusive.  In fact clk_disable must be called before clk_unprepare.
1090 */
1091void clk_unprepare(struct clk *clk)
1092{
1093	if (IS_ERR_OR_NULL(clk))
1094		return;
1095
1096	clk_core_unprepare_lock(clk->core);
1097}
1098EXPORT_SYMBOL_GPL(clk_unprepare);
1099
1100static int clk_core_prepare(struct clk_core *core)
1101{
1102	int ret = 0;
1103
1104	lockdep_assert_held(&prepare_lock);
1105
1106	if (!core)
1107		return 0;
1108
1109	if (core->prepare_count == 0) {
1110		ret = clk_pm_runtime_get(core);
1111		if (ret)
1112			return ret;
1113
1114		ret = clk_core_prepare(core->parent);
1115		if (ret)
1116			goto runtime_put;
1117
1118		trace_clk_prepare(core);
1119
1120		if (core->ops->prepare)
1121			ret = core->ops->prepare(core->hw);
1122
1123		trace_clk_prepare_complete(core);
1124
1125		if (ret)
1126			goto unprepare;
1127	}
1128
1129	core->prepare_count++;
1130
1131	/*
1132	 * CLK_SET_RATE_GATE is a special case of clock protection
1133	 * Instead of a consumer claiming exclusive rate control, it is
1134	 * actually the provider which prevents any consumer from making any
1135	 * operation which could result in a rate change or rate glitch while
1136	 * the clock is prepared.
1137	 */
1138	if (core->flags & CLK_SET_RATE_GATE)
1139		clk_core_rate_protect(core);
1140
1141	return 0;
1142unprepare:
1143	clk_core_unprepare(core->parent);
1144runtime_put:
1145	clk_pm_runtime_put(core);
1146	return ret;
1147}
1148
1149static int clk_core_prepare_lock(struct clk_core *core)
1150{
1151	int ret;
1152
1153	clk_prepare_lock();
1154	ret = clk_core_prepare(core);
1155	clk_prepare_unlock();
1156
1157	return ret;
1158}
1159
1160/**
1161 * clk_prepare - prepare a clock source
1162 * @clk: the clk being prepared
1163 *
1164 * clk_prepare may sleep, which differentiates it from clk_enable.  In a simple
1165 * case, clk_prepare can be used instead of clk_enable to ungate a clk if the
1166 * operation may sleep.  One example is a clk which is accessed over I2c.  In
1167 * the complex case a clk ungate operation may require a fast and a slow part.
1168 * It is this reason that clk_prepare and clk_enable are not mutually
1169 * exclusive.  In fact clk_prepare must be called before clk_enable.
1170 * Returns 0 on success, -EERROR otherwise.
1171 */
1172int clk_prepare(struct clk *clk)
1173{
1174	if (!clk)
1175		return 0;
1176
1177	return clk_core_prepare_lock(clk->core);
1178}
1179EXPORT_SYMBOL_GPL(clk_prepare);
1180
1181static void clk_core_disable(struct clk_core *core)
1182{
1183	lockdep_assert_held(&enable_lock);
1184
1185	if (!core)
1186		return;
1187
1188	if (WARN(core->enable_count == 0, "%s already disabled\n", core->name))
1189		return;
1190
1191	if (WARN(core->enable_count == 1 && core->flags & CLK_IS_CRITICAL,
1192	    "Disabling critical %s\n", core->name))
1193		return;
1194
1195	if (--core->enable_count > 0)
1196		return;
1197
1198	trace_clk_disable(core);
1199
1200	if (core->ops->disable)
1201		core->ops->disable(core->hw);
1202
1203	trace_clk_disable_complete(core);
1204
1205	clk_core_disable(core->parent);
1206}
1207
1208static void clk_core_disable_lock(struct clk_core *core)
1209{
1210	unsigned long flags;
1211
1212	flags = clk_enable_lock();
1213	clk_core_disable(core);
1214	clk_enable_unlock(flags);
1215}
1216
1217/**
1218 * clk_disable - gate a clock
1219 * @clk: the clk being gated
1220 *
1221 * clk_disable must not sleep, which differentiates it from clk_unprepare.  In
1222 * a simple case, clk_disable can be used instead of clk_unprepare to gate a
1223 * clk if the operation is fast and will never sleep.  One example is a
1224 * SoC-internal clk which is controlled via simple register writes.  In the
1225 * complex case a clk gate operation may require a fast and a slow part.  It is
1226 * this reason that clk_unprepare and clk_disable are not mutually exclusive.
1227 * In fact clk_disable must be called before clk_unprepare.
1228 */
1229void clk_disable(struct clk *clk)
1230{
1231	if (IS_ERR_OR_NULL(clk))
1232		return;
1233
1234	clk_core_disable_lock(clk->core);
1235}
1236EXPORT_SYMBOL_GPL(clk_disable);
1237
1238static int clk_core_enable(struct clk_core *core)
1239{
1240	int ret = 0;
1241
1242	lockdep_assert_held(&enable_lock);
1243
1244	if (!core)
1245		return 0;
1246
1247	if (WARN(core->prepare_count == 0,
1248	    "Enabling unprepared %s\n", core->name))
1249		return -ESHUTDOWN;
1250
1251	if (core->enable_count == 0) {
1252		ret = clk_core_enable(core->parent);
1253
1254		if (ret)
1255			return ret;
1256
1257		trace_clk_enable(core);
1258
1259		if (core->ops->enable)
1260			ret = core->ops->enable(core->hw);
1261
1262		trace_clk_enable_complete(core);
1263
1264		if (ret) {
1265			clk_core_disable(core->parent);
1266			return ret;
1267		}
1268	}
1269
1270	core->enable_count++;
1271	return 0;
1272}
1273
1274static int clk_core_enable_lock(struct clk_core *core)
1275{
1276	unsigned long flags;
1277	int ret;
1278
1279	flags = clk_enable_lock();
1280	ret = clk_core_enable(core);
1281	clk_enable_unlock(flags);
1282
1283	return ret;
1284}
1285
1286/**
1287 * clk_gate_restore_context - restore context for poweroff
1288 * @hw: the clk_hw pointer of clock whose state is to be restored
1289 *
1290 * The clock gate restore context function enables or disables
1291 * the gate clocks based on the enable_count. This is done in cases
1292 * where the clock context is lost and based on the enable_count
1293 * the clock either needs to be enabled/disabled. This
1294 * helps restore the state of gate clocks.
1295 */
1296void clk_gate_restore_context(struct clk_hw *hw)
1297{
1298	struct clk_core *core = hw->core;
1299
1300	if (core->enable_count)
1301		core->ops->enable(hw);
1302	else
1303		core->ops->disable(hw);
1304}
1305EXPORT_SYMBOL_GPL(clk_gate_restore_context);
1306
1307static int clk_core_save_context(struct clk_core *core)
1308{
1309	struct clk_core *child;
1310	int ret = 0;
1311
1312	hlist_for_each_entry(child, &core->children, child_node) {
1313		ret = clk_core_save_context(child);
1314		if (ret < 0)
1315			return ret;
1316	}
1317
1318	if (core->ops && core->ops->save_context)
1319		ret = core->ops->save_context(core->hw);
1320
1321	return ret;
1322}
1323
1324static void clk_core_restore_context(struct clk_core *core)
1325{
1326	struct clk_core *child;
1327
1328	if (core->ops && core->ops->restore_context)
1329		core->ops->restore_context(core->hw);
1330
1331	hlist_for_each_entry(child, &core->children, child_node)
1332		clk_core_restore_context(child);
1333}
1334
1335/**
1336 * clk_save_context - save clock context for poweroff
1337 *
1338 * Saves the context of the clock register for powerstates in which the
1339 * contents of the registers will be lost. Occurs deep within the suspend
1340 * code.  Returns 0 on success.
1341 */
1342int clk_save_context(void)
1343{
1344	struct clk_core *clk;
1345	int ret;
1346
1347	hlist_for_each_entry(clk, &clk_root_list, child_node) {
1348		ret = clk_core_save_context(clk);
1349		if (ret < 0)
1350			return ret;
1351	}
1352
1353	hlist_for_each_entry(clk, &clk_orphan_list, child_node) {
1354		ret = clk_core_save_context(clk);
1355		if (ret < 0)
1356			return ret;
1357	}
1358
1359	return 0;
1360}
1361EXPORT_SYMBOL_GPL(clk_save_context);
1362
1363/**
1364 * clk_restore_context - restore clock context after poweroff
1365 *
1366 * Restore the saved clock context upon resume.
1367 *
1368 */
1369void clk_restore_context(void)
1370{
1371	struct clk_core *core;
1372
1373	hlist_for_each_entry(core, &clk_root_list, child_node)
1374		clk_core_restore_context(core);
1375
1376	hlist_for_each_entry(core, &clk_orphan_list, child_node)
1377		clk_core_restore_context(core);
1378}
1379EXPORT_SYMBOL_GPL(clk_restore_context);
1380
1381/**
1382 * clk_enable - ungate a clock
1383 * @clk: the clk being ungated
1384 *
1385 * clk_enable must not sleep, which differentiates it from clk_prepare.  In a
1386 * simple case, clk_enable can be used instead of clk_prepare to ungate a clk
1387 * if the operation will never sleep.  One example is a SoC-internal clk which
1388 * is controlled via simple register writes.  In the complex case a clk ungate
1389 * operation may require a fast and a slow part.  It is this reason that
1390 * clk_enable and clk_prepare are not mutually exclusive.  In fact clk_prepare
1391 * must be called before clk_enable.  Returns 0 on success, -EERROR
1392 * otherwise.
1393 */
1394int clk_enable(struct clk *clk)
1395{
1396	if (!clk)
1397		return 0;
1398
1399	return clk_core_enable_lock(clk->core);
1400}
1401EXPORT_SYMBOL_GPL(clk_enable);
1402
1403/**
1404 * clk_is_enabled_when_prepared - indicate if preparing a clock also enables it.
1405 * @clk: clock source
1406 *
1407 * Returns true if clk_prepare() implicitly enables the clock, effectively
1408 * making clk_enable()/clk_disable() no-ops, false otherwise.
1409 *
1410 * This is of interest mainly to power management code where actually
1411 * disabling the clock also requires unpreparing it to have any material
1412 * effect.
1413 *
1414 * Regardless of the value returned here, the caller must always invoke
1415 * clk_enable() or clk_prepare_enable()  and counterparts for usage counts
1416 * to be right.
1417 */
1418bool clk_is_enabled_when_prepared(struct clk *clk)
1419{
1420	return clk && !(clk->core->ops->enable && clk->core->ops->disable);
1421}
1422EXPORT_SYMBOL_GPL(clk_is_enabled_when_prepared);
1423
1424static int clk_core_prepare_enable(struct clk_core *core)
1425{
1426	int ret;
1427
1428	ret = clk_core_prepare_lock(core);
1429	if (ret)
1430		return ret;
1431
1432	ret = clk_core_enable_lock(core);
1433	if (ret)
1434		clk_core_unprepare_lock(core);
1435
1436	return ret;
1437}
1438
1439static void clk_core_disable_unprepare(struct clk_core *core)
1440{
1441	clk_core_disable_lock(core);
1442	clk_core_unprepare_lock(core);
1443}
1444
1445static void __init clk_unprepare_unused_subtree(struct clk_core *core)
1446{
1447	struct clk_core *child;
1448
1449	lockdep_assert_held(&prepare_lock);
1450
1451	hlist_for_each_entry(child, &core->children, child_node)
1452		clk_unprepare_unused_subtree(child);
1453
1454	if (core->prepare_count)
1455		return;
1456
1457	if (core->flags & CLK_IGNORE_UNUSED)
1458		return;
1459
1460	if (clk_core_is_prepared(core)) {
1461		trace_clk_unprepare(core);
1462		if (core->ops->unprepare_unused)
1463			core->ops->unprepare_unused(core->hw);
1464		else if (core->ops->unprepare)
1465			core->ops->unprepare(core->hw);
1466		trace_clk_unprepare_complete(core);
1467	}
1468}
1469
1470static void __init clk_disable_unused_subtree(struct clk_core *core)
1471{
1472	struct clk_core *child;
1473	unsigned long flags;
1474
1475	lockdep_assert_held(&prepare_lock);
1476
1477	hlist_for_each_entry(child, &core->children, child_node)
1478		clk_disable_unused_subtree(child);
1479
1480	if (core->flags & CLK_OPS_PARENT_ENABLE)
1481		clk_core_prepare_enable(core->parent);
1482
1483	flags = clk_enable_lock();
1484
1485	if (core->enable_count)
1486		goto unlock_out;
1487
1488	if (core->flags & CLK_IGNORE_UNUSED)
1489		goto unlock_out;
1490
1491	/*
1492	 * some gate clocks have special needs during the disable-unused
1493	 * sequence.  call .disable_unused if available, otherwise fall
1494	 * back to .disable
1495	 */
1496	if (clk_core_is_enabled(core)) {
1497		trace_clk_disable(core);
1498		if (core->ops->disable_unused)
1499			core->ops->disable_unused(core->hw);
1500		else if (core->ops->disable)
1501			core->ops->disable(core->hw);
1502		trace_clk_disable_complete(core);
1503	}
1504
1505unlock_out:
1506	clk_enable_unlock(flags);
1507	if (core->flags & CLK_OPS_PARENT_ENABLE)
1508		clk_core_disable_unprepare(core->parent);
1509}
1510
1511static bool clk_ignore_unused __initdata;
1512static int __init clk_ignore_unused_setup(char *__unused)
1513{
1514	clk_ignore_unused = true;
1515	return 1;
1516}
1517__setup("clk_ignore_unused", clk_ignore_unused_setup);
1518
1519static int __init clk_disable_unused(void)
1520{
1521	struct clk_core *core;
1522	int ret;
1523
1524	if (clk_ignore_unused) {
1525		pr_warn("clk: Not disabling unused clocks\n");
1526		return 0;
1527	}
1528
1529	pr_info("clk: Disabling unused clocks\n");
1530
1531	ret = clk_pm_runtime_get_all();
1532	if (ret)
1533		return ret;
1534	/*
1535	 * Grab the prepare lock to keep the clk topology stable while iterating
1536	 * over clks.
1537	 */
1538	clk_prepare_lock();
1539
1540	hlist_for_each_entry(core, &clk_root_list, child_node)
1541		clk_disable_unused_subtree(core);
1542
1543	hlist_for_each_entry(core, &clk_orphan_list, child_node)
1544		clk_disable_unused_subtree(core);
1545
1546	hlist_for_each_entry(core, &clk_root_list, child_node)
1547		clk_unprepare_unused_subtree(core);
1548
1549	hlist_for_each_entry(core, &clk_orphan_list, child_node)
1550		clk_unprepare_unused_subtree(core);
1551
1552	clk_prepare_unlock();
1553
1554	clk_pm_runtime_put_all();
1555
1556	return 0;
1557}
1558late_initcall_sync(clk_disable_unused);
1559
1560static int clk_core_determine_round_nolock(struct clk_core *core,
1561					   struct clk_rate_request *req)
1562{
1563	long rate;
1564
1565	lockdep_assert_held(&prepare_lock);
1566
1567	if (!core)
1568		return 0;
1569
1570	/*
1571	 * Some clock providers hand-craft their clk_rate_requests and
1572	 * might not fill min_rate and max_rate.
1573	 *
1574	 * If it's the case, clamping the rate is equivalent to setting
1575	 * the rate to 0 which is bad. Skip the clamping but complain so
1576	 * that it gets fixed, hopefully.
1577	 */
1578	if (!req->min_rate && !req->max_rate)
1579		pr_warn("%s: %s: clk_rate_request has initialized min or max rate.\n",
1580			__func__, core->name);
1581	else
1582		req->rate = clamp(req->rate, req->min_rate, req->max_rate);
1583
1584	/*
1585	 * At this point, core protection will be disabled
1586	 * - if the provider is not protected at all
1587	 * - if the calling consumer is the only one which has exclusivity
1588	 *   over the provider
1589	 */
1590	if (clk_core_rate_is_protected(core)) {
1591		req->rate = core->rate;
1592	} else if (core->ops->determine_rate) {
1593		return core->ops->determine_rate(core->hw, req);
1594	} else if (core->ops->round_rate) {
1595		rate = core->ops->round_rate(core->hw, req->rate,
1596					     &req->best_parent_rate);
1597		if (rate < 0)
1598			return rate;
1599
1600		req->rate = rate;
1601	} else {
1602		return -EINVAL;
1603	}
1604
1605	return 0;
1606}
1607
1608static void clk_core_init_rate_req(struct clk_core * const core,
1609				   struct clk_rate_request *req,
1610				   unsigned long rate)
1611{
1612	struct clk_core *parent;
1613
1614	if (WARN_ON(!req))
1615		return;
1616
1617	memset(req, 0, sizeof(*req));
1618	req->max_rate = ULONG_MAX;
1619
1620	if (!core)
1621		return;
1622
1623	req->core = core;
1624	req->rate = rate;
1625	clk_core_get_boundaries(core, &req->min_rate, &req->max_rate);
1626
1627	parent = core->parent;
1628	if (parent) {
1629		req->best_parent_hw = parent->hw;
1630		req->best_parent_rate = parent->rate;
1631	} else {
1632		req->best_parent_hw = NULL;
1633		req->best_parent_rate = 0;
1634	}
1635}
1636
1637/**
1638 * clk_hw_init_rate_request - Initializes a clk_rate_request
1639 * @hw: the clk for which we want to submit a rate request
1640 * @req: the clk_rate_request structure we want to initialise
1641 * @rate: the rate which is to be requested
1642 *
1643 * Initializes a clk_rate_request structure to submit to
1644 * __clk_determine_rate() or similar functions.
1645 */
1646void clk_hw_init_rate_request(const struct clk_hw *hw,
1647			      struct clk_rate_request *req,
1648			      unsigned long rate)
1649{
1650	if (WARN_ON(!hw || !req))
1651		return;
1652
1653	clk_core_init_rate_req(hw->core, req, rate);
1654}
1655EXPORT_SYMBOL_GPL(clk_hw_init_rate_request);
1656
1657/**
1658 * clk_hw_forward_rate_request - Forwards a clk_rate_request to a clock's parent
1659 * @hw: the original clock that got the rate request
1660 * @old_req: the original clk_rate_request structure we want to forward
1661 * @parent: the clk we want to forward @old_req to
1662 * @req: the clk_rate_request structure we want to initialise
1663 * @parent_rate: The rate which is to be requested to @parent
1664 *
1665 * Initializes a clk_rate_request structure to submit to a clock parent
1666 * in __clk_determine_rate() or similar functions.
1667 */
1668void clk_hw_forward_rate_request(const struct clk_hw *hw,
1669				 const struct clk_rate_request *old_req,
1670				 const struct clk_hw *parent,
1671				 struct clk_rate_request *req,
1672				 unsigned long parent_rate)
1673{
1674	if (WARN_ON(!hw || !old_req || !parent || !req))
1675		return;
1676
1677	clk_core_forward_rate_req(hw->core, old_req,
1678				  parent->core, req,
1679				  parent_rate);
1680}
1681EXPORT_SYMBOL_GPL(clk_hw_forward_rate_request);
1682
1683static bool clk_core_can_round(struct clk_core * const core)
1684{
1685	return core->ops->determine_rate || core->ops->round_rate;
1686}
1687
1688static int clk_core_round_rate_nolock(struct clk_core *core,
1689				      struct clk_rate_request *req)
1690{
1691	int ret;
1692
1693	lockdep_assert_held(&prepare_lock);
1694
1695	if (!core) {
1696		req->rate = 0;
1697		return 0;
1698	}
1699
1700	if (clk_core_can_round(core))
1701		return clk_core_determine_round_nolock(core, req);
1702
1703	if (core->flags & CLK_SET_RATE_PARENT) {
1704		struct clk_rate_request parent_req;
1705
1706		clk_core_forward_rate_req(core, req, core->parent, &parent_req, req->rate);
1707
1708		trace_clk_rate_request_start(&parent_req);
1709
1710		ret = clk_core_round_rate_nolock(core->parent, &parent_req);
1711		if (ret)
1712			return ret;
1713
1714		trace_clk_rate_request_done(&parent_req);
1715
1716		req->best_parent_rate = parent_req.rate;
1717		req->rate = parent_req.rate;
1718
1719		return 0;
1720	}
1721
1722	req->rate = core->rate;
1723	return 0;
1724}
1725
1726/**
1727 * __clk_determine_rate - get the closest rate actually supported by a clock
1728 * @hw: determine the rate of this clock
1729 * @req: target rate request
1730 *
1731 * Useful for clk_ops such as .set_rate and .determine_rate.
1732 */
1733int __clk_determine_rate(struct clk_hw *hw, struct clk_rate_request *req)
1734{
1735	if (!hw) {
1736		req->rate = 0;
1737		return 0;
1738	}
1739
1740	return clk_core_round_rate_nolock(hw->core, req);
1741}
1742EXPORT_SYMBOL_GPL(__clk_determine_rate);
1743
1744/**
1745 * clk_hw_round_rate() - round the given rate for a hw clk
1746 * @hw: the hw clk for which we are rounding a rate
1747 * @rate: the rate which is to be rounded
1748 *
1749 * Takes in a rate as input and rounds it to a rate that the clk can actually
1750 * use.
1751 *
1752 * Context: prepare_lock must be held.
1753 *          For clk providers to call from within clk_ops such as .round_rate,
1754 *          .determine_rate.
1755 *
1756 * Return: returns rounded rate of hw clk if clk supports round_rate operation
1757 *         else returns the parent rate.
1758 */
1759unsigned long clk_hw_round_rate(struct clk_hw *hw, unsigned long rate)
1760{
1761	int ret;
1762	struct clk_rate_request req;
1763
1764	clk_core_init_rate_req(hw->core, &req, rate);
1765
1766	trace_clk_rate_request_start(&req);
1767
1768	ret = clk_core_round_rate_nolock(hw->core, &req);
1769	if (ret)
1770		return 0;
1771
1772	trace_clk_rate_request_done(&req);
1773
1774	return req.rate;
1775}
1776EXPORT_SYMBOL_GPL(clk_hw_round_rate);
1777
1778/**
1779 * clk_round_rate - round the given rate for a clk
1780 * @clk: the clk for which we are rounding a rate
1781 * @rate: the rate which is to be rounded
1782 *
1783 * Takes in a rate as input and rounds it to a rate that the clk can actually
1784 * use which is then returned.  If clk doesn't support round_rate operation
1785 * then the parent rate is returned.
1786 */
1787long clk_round_rate(struct clk *clk, unsigned long rate)
1788{
1789	struct clk_rate_request req;
1790	int ret;
1791
1792	if (!clk)
1793		return 0;
1794
1795	clk_prepare_lock();
1796
1797	if (clk->exclusive_count)
1798		clk_core_rate_unprotect(clk->core);
1799
1800	clk_core_init_rate_req(clk->core, &req, rate);
1801
1802	trace_clk_rate_request_start(&req);
1803
1804	ret = clk_core_round_rate_nolock(clk->core, &req);
1805
1806	trace_clk_rate_request_done(&req);
1807
1808	if (clk->exclusive_count)
1809		clk_core_rate_protect(clk->core);
1810
1811	clk_prepare_unlock();
1812
1813	if (ret)
1814		return ret;
1815
1816	return req.rate;
1817}
1818EXPORT_SYMBOL_GPL(clk_round_rate);
1819
1820/**
1821 * __clk_notify - call clk notifier chain
1822 * @core: clk that is changing rate
1823 * @msg: clk notifier type (see include/linux/clk.h)
1824 * @old_rate: old clk rate
1825 * @new_rate: new clk rate
1826 *
1827 * Triggers a notifier call chain on the clk rate-change notification
1828 * for 'clk'.  Passes a pointer to the struct clk and the previous
1829 * and current rates to the notifier callback.  Intended to be called by
1830 * internal clock code only.  Returns NOTIFY_DONE from the last driver
1831 * called if all went well, or NOTIFY_STOP or NOTIFY_BAD immediately if
1832 * a driver returns that.
1833 */
1834static int __clk_notify(struct clk_core *core, unsigned long msg,
1835		unsigned long old_rate, unsigned long new_rate)
1836{
1837	struct clk_notifier *cn;
1838	struct clk_notifier_data cnd;
1839	int ret = NOTIFY_DONE;
1840
1841	cnd.old_rate = old_rate;
1842	cnd.new_rate = new_rate;
1843
1844	list_for_each_entry(cn, &clk_notifier_list, node) {
1845		if (cn->clk->core == core) {
1846			cnd.clk = cn->clk;
1847			ret = srcu_notifier_call_chain(&cn->notifier_head, msg,
1848					&cnd);
1849			if (ret & NOTIFY_STOP_MASK)
1850				return ret;
1851		}
1852	}
1853
1854	return ret;
1855}
1856
1857/**
1858 * __clk_recalc_accuracies
1859 * @core: first clk in the subtree
1860 *
1861 * Walks the subtree of clks starting with clk and recalculates accuracies as
1862 * it goes.  Note that if a clk does not implement the .recalc_accuracy
1863 * callback then it is assumed that the clock will take on the accuracy of its
1864 * parent.
1865 */
1866static void __clk_recalc_accuracies(struct clk_core *core)
1867{
1868	unsigned long parent_accuracy = 0;
1869	struct clk_core *child;
1870
1871	lockdep_assert_held(&prepare_lock);
1872
1873	if (core->parent)
1874		parent_accuracy = core->parent->accuracy;
1875
1876	if (core->ops->recalc_accuracy)
1877		core->accuracy = core->ops->recalc_accuracy(core->hw,
1878							  parent_accuracy);
1879	else
1880		core->accuracy = parent_accuracy;
1881
1882	hlist_for_each_entry(child, &core->children, child_node)
1883		__clk_recalc_accuracies(child);
1884}
1885
1886static long clk_core_get_accuracy_recalc(struct clk_core *core)
1887{
1888	if (core && (core->flags & CLK_GET_ACCURACY_NOCACHE))
1889		__clk_recalc_accuracies(core);
1890
1891	return clk_core_get_accuracy_no_lock(core);
1892}
1893
1894/**
1895 * clk_get_accuracy - return the accuracy of clk
1896 * @clk: the clk whose accuracy is being returned
1897 *
1898 * Simply returns the cached accuracy of the clk, unless
1899 * CLK_GET_ACCURACY_NOCACHE flag is set, which means a recalc_rate will be
1900 * issued.
1901 * If clk is NULL then returns 0.
1902 */
1903long clk_get_accuracy(struct clk *clk)
1904{
1905	long accuracy;
1906
1907	if (!clk)
1908		return 0;
1909
1910	clk_prepare_lock();
1911	accuracy = clk_core_get_accuracy_recalc(clk->core);
1912	clk_prepare_unlock();
1913
1914	return accuracy;
1915}
1916EXPORT_SYMBOL_GPL(clk_get_accuracy);
1917
1918static unsigned long clk_recalc(struct clk_core *core,
1919				unsigned long parent_rate)
1920{
1921	unsigned long rate = parent_rate;
1922
1923	if (core->ops->recalc_rate && !clk_pm_runtime_get(core)) {
1924		rate = core->ops->recalc_rate(core->hw, parent_rate);
1925		clk_pm_runtime_put(core);
1926	}
1927	return rate;
1928}
1929
1930/**
1931 * __clk_recalc_rates
1932 * @core: first clk in the subtree
1933 * @update_req: Whether req_rate should be updated with the new rate
1934 * @msg: notification type (see include/linux/clk.h)
1935 *
1936 * Walks the subtree of clks starting with clk and recalculates rates as it
1937 * goes.  Note that if a clk does not implement the .recalc_rate callback then
1938 * it is assumed that the clock will take on the rate of its parent.
1939 *
1940 * clk_recalc_rates also propagates the POST_RATE_CHANGE notification,
1941 * if necessary.
1942 */
1943static void __clk_recalc_rates(struct clk_core *core, bool update_req,
1944			       unsigned long msg)
1945{
1946	unsigned long old_rate;
1947	unsigned long parent_rate = 0;
1948	struct clk_core *child;
1949
1950	lockdep_assert_held(&prepare_lock);
1951
1952	old_rate = core->rate;
1953
1954	if (core->parent)
1955		parent_rate = core->parent->rate;
1956
1957	core->rate = clk_recalc(core, parent_rate);
1958	if (update_req)
1959		core->req_rate = core->rate;
1960
1961	/*
1962	 * ignore NOTIFY_STOP and NOTIFY_BAD return values for POST_RATE_CHANGE
1963	 * & ABORT_RATE_CHANGE notifiers
1964	 */
1965	if (core->notifier_count && msg)
1966		__clk_notify(core, msg, old_rate, core->rate);
1967
1968	hlist_for_each_entry(child, &core->children, child_node)
1969		__clk_recalc_rates(child, update_req, msg);
1970}
1971
1972static unsigned long clk_core_get_rate_recalc(struct clk_core *core)
1973{
1974	if (core && (core->flags & CLK_GET_RATE_NOCACHE))
1975		__clk_recalc_rates(core, false, 0);
1976
1977	return clk_core_get_rate_nolock(core);
1978}
1979
1980/**
1981 * clk_get_rate - return the rate of clk
1982 * @clk: the clk whose rate is being returned
1983 *
1984 * Simply returns the cached rate of the clk, unless CLK_GET_RATE_NOCACHE flag
1985 * is set, which means a recalc_rate will be issued. Can be called regardless of
1986 * the clock enabledness. If clk is NULL, or if an error occurred, then returns
1987 * 0.
1988 */
1989unsigned long clk_get_rate(struct clk *clk)
1990{
1991	unsigned long rate;
1992
1993	if (!clk)
1994		return 0;
1995
1996	clk_prepare_lock();
1997	rate = clk_core_get_rate_recalc(clk->core);
1998	clk_prepare_unlock();
1999
2000	return rate;
2001}
2002EXPORT_SYMBOL_GPL(clk_get_rate);
2003
2004static int clk_fetch_parent_index(struct clk_core *core,
2005				  struct clk_core *parent)
2006{
2007	int i;
2008
2009	if (!parent)
2010		return -EINVAL;
2011
2012	for (i = 0; i < core->num_parents; i++) {
2013		/* Found it first try! */
2014		if (core->parents[i].core == parent)
2015			return i;
2016
2017		/* Something else is here, so keep looking */
2018		if (core->parents[i].core)
2019			continue;
2020
2021		/* Maybe core hasn't been cached but the hw is all we know? */
2022		if (core->parents[i].hw) {
2023			if (core->parents[i].hw == parent->hw)
2024				break;
2025
2026			/* Didn't match, but we're expecting a clk_hw */
2027			continue;
2028		}
2029
2030		/* Maybe it hasn't been cached (clk_set_parent() path) */
2031		if (parent == clk_core_get(core, i))
2032			break;
2033
2034		/* Fallback to comparing globally unique names */
2035		if (core->parents[i].name &&
2036		    !strcmp(parent->name, core->parents[i].name))
2037			break;
2038	}
2039
2040	if (i == core->num_parents)
2041		return -EINVAL;
2042
2043	core->parents[i].core = parent;
2044	return i;
2045}
2046
2047/**
2048 * clk_hw_get_parent_index - return the index of the parent clock
2049 * @hw: clk_hw associated with the clk being consumed
2050 *
2051 * Fetches and returns the index of parent clock. Returns -EINVAL if the given
2052 * clock does not have a current parent.
2053 */
2054int clk_hw_get_parent_index(struct clk_hw *hw)
2055{
2056	struct clk_hw *parent = clk_hw_get_parent(hw);
2057
2058	if (WARN_ON(parent == NULL))
2059		return -EINVAL;
2060
2061	return clk_fetch_parent_index(hw->core, parent->core);
2062}
2063EXPORT_SYMBOL_GPL(clk_hw_get_parent_index);
2064
2065/*
2066 * Update the orphan status of @core and all its children.
2067 */
2068static void clk_core_update_orphan_status(struct clk_core *core, bool is_orphan)
2069{
2070	struct clk_core *child;
2071
2072	core->orphan = is_orphan;
2073
2074	hlist_for_each_entry(child, &core->children, child_node)
2075		clk_core_update_orphan_status(child, is_orphan);
2076}
2077
2078static void clk_reparent(struct clk_core *core, struct clk_core *new_parent)
2079{
2080	bool was_orphan = core->orphan;
2081
2082	hlist_del(&core->child_node);
2083
2084	if (new_parent) {
2085		bool becomes_orphan = new_parent->orphan;
2086
2087		/* avoid duplicate POST_RATE_CHANGE notifications */
2088		if (new_parent->new_child == core)
2089			new_parent->new_child = NULL;
2090
2091		hlist_add_head(&core->child_node, &new_parent->children);
2092
2093		if (was_orphan != becomes_orphan)
2094			clk_core_update_orphan_status(core, becomes_orphan);
2095	} else {
2096		hlist_add_head(&core->child_node, &clk_orphan_list);
2097		if (!was_orphan)
2098			clk_core_update_orphan_status(core, true);
2099	}
2100
2101	core->parent = new_parent;
2102}
2103
2104static struct clk_core *__clk_set_parent_before(struct clk_core *core,
2105					   struct clk_core *parent)
2106{
2107	unsigned long flags;
2108	struct clk_core *old_parent = core->parent;
2109
2110	/*
2111	 * 1. enable parents for CLK_OPS_PARENT_ENABLE clock
2112	 *
2113	 * 2. Migrate prepare state between parents and prevent race with
2114	 * clk_enable().
2115	 *
2116	 * If the clock is not prepared, then a race with
2117	 * clk_enable/disable() is impossible since we already have the
2118	 * prepare lock (future calls to clk_enable() need to be preceded by
2119	 * a clk_prepare()).
2120	 *
2121	 * If the clock is prepared, migrate the prepared state to the new
2122	 * parent and also protect against a race with clk_enable() by
2123	 * forcing the clock and the new parent on.  This ensures that all
2124	 * future calls to clk_enable() are practically NOPs with respect to
2125	 * hardware and software states.
2126	 *
2127	 * See also: Comment for clk_set_parent() below.
2128	 */
2129
2130	/* enable old_parent & parent if CLK_OPS_PARENT_ENABLE is set */
2131	if (core->flags & CLK_OPS_PARENT_ENABLE) {
2132		clk_core_prepare_enable(old_parent);
2133		clk_core_prepare_enable(parent);
2134	}
2135
2136	/* migrate prepare count if > 0 */
2137	if (core->prepare_count) {
2138		clk_core_prepare_enable(parent);
2139		clk_core_enable_lock(core);
2140	}
2141
2142	/* update the clk tree topology */
2143	flags = clk_enable_lock();
2144	clk_reparent(core, parent);
2145	clk_enable_unlock(flags);
2146
2147	return old_parent;
2148}
2149
2150static void __clk_set_parent_after(struct clk_core *core,
2151				   struct clk_core *parent,
2152				   struct clk_core *old_parent)
2153{
2154	/*
2155	 * Finish the migration of prepare state and undo the changes done
2156	 * for preventing a race with clk_enable().
2157	 */
2158	if (core->prepare_count) {
2159		clk_core_disable_lock(core);
2160		clk_core_disable_unprepare(old_parent);
2161	}
2162
2163	/* re-balance ref counting if CLK_OPS_PARENT_ENABLE is set */
2164	if (core->flags & CLK_OPS_PARENT_ENABLE) {
2165		clk_core_disable_unprepare(parent);
2166		clk_core_disable_unprepare(old_parent);
2167	}
2168}
2169
2170static int __clk_set_parent(struct clk_core *core, struct clk_core *parent,
2171			    u8 p_index)
2172{
2173	unsigned long flags;
2174	int ret = 0;
2175	struct clk_core *old_parent;
2176
2177	old_parent = __clk_set_parent_before(core, parent);
2178
2179	trace_clk_set_parent(core, parent);
2180
2181	/* change clock input source */
2182	if (parent && core->ops->set_parent)
2183		ret = core->ops->set_parent(core->hw, p_index);
2184
2185	trace_clk_set_parent_complete(core, parent);
2186
2187	if (ret) {
2188		flags = clk_enable_lock();
2189		clk_reparent(core, old_parent);
2190		clk_enable_unlock(flags);
2191
2192		__clk_set_parent_after(core, old_parent, parent);
2193
2194		return ret;
2195	}
2196
2197	__clk_set_parent_after(core, parent, old_parent);
2198
2199	return 0;
2200}
2201
2202/**
2203 * __clk_speculate_rates
2204 * @core: first clk in the subtree
2205 * @parent_rate: the "future" rate of clk's parent
2206 *
2207 * Walks the subtree of clks starting with clk, speculating rates as it
2208 * goes and firing off PRE_RATE_CHANGE notifications as necessary.
2209 *
2210 * Unlike clk_recalc_rates, clk_speculate_rates exists only for sending
2211 * pre-rate change notifications and returns early if no clks in the
2212 * subtree have subscribed to the notifications.  Note that if a clk does not
2213 * implement the .recalc_rate callback then it is assumed that the clock will
2214 * take on the rate of its parent.
2215 */
2216static int __clk_speculate_rates(struct clk_core *core,
2217				 unsigned long parent_rate)
2218{
2219	struct clk_core *child;
2220	unsigned long new_rate;
2221	int ret = NOTIFY_DONE;
2222
2223	lockdep_assert_held(&prepare_lock);
2224
2225	new_rate = clk_recalc(core, parent_rate);
2226
2227	/* abort rate change if a driver returns NOTIFY_BAD or NOTIFY_STOP */
2228	if (core->notifier_count)
2229		ret = __clk_notify(core, PRE_RATE_CHANGE, core->rate, new_rate);
2230
2231	if (ret & NOTIFY_STOP_MASK) {
2232		pr_debug("%s: clk notifier callback for clock %s aborted with error %d\n",
2233				__func__, core->name, ret);
2234		goto out;
2235	}
2236
2237	hlist_for_each_entry(child, &core->children, child_node) {
2238		ret = __clk_speculate_rates(child, new_rate);
2239		if (ret & NOTIFY_STOP_MASK)
2240			break;
2241	}
2242
2243out:
2244	return ret;
2245}
2246
2247static void clk_calc_subtree(struct clk_core *core, unsigned long new_rate,
2248			     struct clk_core *new_parent, u8 p_index)
2249{
2250	struct clk_core *child;
2251
2252	core->new_rate = new_rate;
2253	core->new_parent = new_parent;
2254	core->new_parent_index = p_index;
2255	/* include clk in new parent's PRE_RATE_CHANGE notifications */
2256	core->new_child = NULL;
2257	if (new_parent && new_parent != core->parent)
2258		new_parent->new_child = core;
2259
2260	hlist_for_each_entry(child, &core->children, child_node) {
2261		child->new_rate = clk_recalc(child, new_rate);
2262		clk_calc_subtree(child, child->new_rate, NULL, 0);
2263	}
2264}
2265
2266/*
2267 * calculate the new rates returning the topmost clock that has to be
2268 * changed.
2269 */
2270static struct clk_core *clk_calc_new_rates(struct clk_core *core,
2271					   unsigned long rate)
2272{
2273	struct clk_core *top = core;
2274	struct clk_core *old_parent, *parent;
2275	unsigned long best_parent_rate = 0;
2276	unsigned long new_rate;
2277	unsigned long min_rate;
2278	unsigned long max_rate;
2279	int p_index = 0;
2280	int ret;
2281
2282	/* sanity */
2283	if (IS_ERR_OR_NULL(core))
2284		return NULL;
2285
2286	/* save parent rate, if it exists */
2287	parent = old_parent = core->parent;
2288	if (parent)
2289		best_parent_rate = parent->rate;
2290
2291	clk_core_get_boundaries(core, &min_rate, &max_rate);
2292
2293	/* find the closest rate and parent clk/rate */
2294	if (clk_core_can_round(core)) {
2295		struct clk_rate_request req;
2296
2297		clk_core_init_rate_req(core, &req, rate);
2298
2299		trace_clk_rate_request_start(&req);
2300
2301		ret = clk_core_determine_round_nolock(core, &req);
2302		if (ret < 0)
2303			return NULL;
2304
2305		trace_clk_rate_request_done(&req);
2306
2307		best_parent_rate = req.best_parent_rate;
2308		new_rate = req.rate;
2309		parent = req.best_parent_hw ? req.best_parent_hw->core : NULL;
2310
2311		if (new_rate < min_rate || new_rate > max_rate)
2312			return NULL;
2313	} else if (!parent || !(core->flags & CLK_SET_RATE_PARENT)) {
2314		/* pass-through clock without adjustable parent */
2315		core->new_rate = core->rate;
2316		return NULL;
2317	} else {
2318		/* pass-through clock with adjustable parent */
2319		top = clk_calc_new_rates(parent, rate);
2320		new_rate = parent->new_rate;
2321		goto out;
2322	}
2323
2324	/* some clocks must be gated to change parent */
2325	if (parent != old_parent &&
2326	    (core->flags & CLK_SET_PARENT_GATE) && core->prepare_count) {
2327		pr_debug("%s: %s not gated but wants to reparent\n",
2328			 __func__, core->name);
2329		return NULL;
2330	}
2331
2332	/* try finding the new parent index */
2333	if (parent && core->num_parents > 1) {
2334		p_index = clk_fetch_parent_index(core, parent);
2335		if (p_index < 0) {
2336			pr_debug("%s: clk %s can not be parent of clk %s\n",
2337				 __func__, parent->name, core->name);
2338			return NULL;
2339		}
2340	}
2341
2342	if ((core->flags & CLK_SET_RATE_PARENT) && parent &&
2343	    best_parent_rate != parent->rate)
2344		top = clk_calc_new_rates(parent, best_parent_rate);
2345
2346out:
2347	clk_calc_subtree(core, new_rate, parent, p_index);
2348
2349	return top;
2350}
2351
2352/*
2353 * Notify about rate changes in a subtree. Always walk down the whole tree
2354 * so that in case of an error we can walk down the whole tree again and
2355 * abort the change.
2356 */
2357static struct clk_core *clk_propagate_rate_change(struct clk_core *core,
2358						  unsigned long event)
2359{
2360	struct clk_core *child, *tmp_clk, *fail_clk = NULL;
2361	int ret = NOTIFY_DONE;
2362
2363	if (core->rate == core->new_rate)
2364		return NULL;
2365
2366	if (core->notifier_count) {
2367		ret = __clk_notify(core, event, core->rate, core->new_rate);
2368		if (ret & NOTIFY_STOP_MASK)
2369			fail_clk = core;
2370	}
2371
2372	hlist_for_each_entry(child, &core->children, child_node) {
2373		/* Skip children who will be reparented to another clock */
2374		if (child->new_parent && child->new_parent != core)
2375			continue;
2376		tmp_clk = clk_propagate_rate_change(child, event);
2377		if (tmp_clk)
2378			fail_clk = tmp_clk;
2379	}
2380
2381	/* handle the new child who might not be in core->children yet */
2382	if (core->new_child) {
2383		tmp_clk = clk_propagate_rate_change(core->new_child, event);
2384		if (tmp_clk)
2385			fail_clk = tmp_clk;
2386	}
2387
2388	return fail_clk;
2389}
2390
2391/*
2392 * walk down a subtree and set the new rates notifying the rate
2393 * change on the way
2394 */
2395static void clk_change_rate(struct clk_core *core)
2396{
2397	struct clk_core *child;
2398	struct hlist_node *tmp;
2399	unsigned long old_rate;
2400	unsigned long best_parent_rate = 0;
2401	bool skip_set_rate = false;
2402	struct clk_core *old_parent;
2403	struct clk_core *parent = NULL;
2404
2405	old_rate = core->rate;
2406
2407	if (core->new_parent) {
2408		parent = core->new_parent;
2409		best_parent_rate = core->new_parent->rate;
2410	} else if (core->parent) {
2411		parent = core->parent;
2412		best_parent_rate = core->parent->rate;
2413	}
2414
2415	if (clk_pm_runtime_get(core))
2416		return;
2417
2418	if (core->flags & CLK_SET_RATE_UNGATE) {
2419		clk_core_prepare(core);
2420		clk_core_enable_lock(core);
2421	}
2422
2423	if (core->new_parent && core->new_parent != core->parent) {
2424		old_parent = __clk_set_parent_before(core, core->new_parent);
2425		trace_clk_set_parent(core, core->new_parent);
2426
2427		if (core->ops->set_rate_and_parent) {
2428			skip_set_rate = true;
2429			core->ops->set_rate_and_parent(core->hw, core->new_rate,
2430					best_parent_rate,
2431					core->new_parent_index);
2432		} else if (core->ops->set_parent) {
2433			core->ops->set_parent(core->hw, core->new_parent_index);
2434		}
2435
2436		trace_clk_set_parent_complete(core, core->new_parent);
2437		__clk_set_parent_after(core, core->new_parent, old_parent);
2438	}
2439
2440	if (core->flags & CLK_OPS_PARENT_ENABLE)
2441		clk_core_prepare_enable(parent);
2442
2443	trace_clk_set_rate(core, core->new_rate);
2444
2445	if (!skip_set_rate && core->ops->set_rate)
2446		core->ops->set_rate(core->hw, core->new_rate, best_parent_rate);
2447
2448	trace_clk_set_rate_complete(core, core->new_rate);
2449
2450	core->rate = clk_recalc(core, best_parent_rate);
2451
2452	if (core->flags & CLK_SET_RATE_UNGATE) {
2453		clk_core_disable_lock(core);
2454		clk_core_unprepare(core);
2455	}
2456
2457	if (core->flags & CLK_OPS_PARENT_ENABLE)
2458		clk_core_disable_unprepare(parent);
2459
2460	if (core->notifier_count && old_rate != core->rate)
2461		__clk_notify(core, POST_RATE_CHANGE, old_rate, core->rate);
2462
2463	if (core->flags & CLK_RECALC_NEW_RATES)
2464		(void)clk_calc_new_rates(core, core->new_rate);
2465
2466	/*
2467	 * Use safe iteration, as change_rate can actually swap parents
2468	 * for certain clock types.
2469	 */
2470	hlist_for_each_entry_safe(child, tmp, &core->children, child_node) {
2471		/* Skip children who will be reparented to another clock */
2472		if (child->new_parent && child->new_parent != core)
2473			continue;
2474		clk_change_rate(child);
2475	}
2476
2477	/* handle the new child who might not be in core->children yet */
2478	if (core->new_child)
2479		clk_change_rate(core->new_child);
2480
2481	clk_pm_runtime_put(core);
2482}
2483
2484static unsigned long clk_core_req_round_rate_nolock(struct clk_core *core,
2485						     unsigned long req_rate)
2486{
2487	int ret, cnt;
2488	struct clk_rate_request req;
2489
2490	lockdep_assert_held(&prepare_lock);
2491
2492	if (!core)
2493		return 0;
2494
2495	/* simulate what the rate would be if it could be freely set */
2496	cnt = clk_core_rate_nuke_protect(core);
2497	if (cnt < 0)
2498		return cnt;
2499
2500	clk_core_init_rate_req(core, &req, req_rate);
2501
2502	trace_clk_rate_request_start(&req);
2503
2504	ret = clk_core_round_rate_nolock(core, &req);
2505
2506	trace_clk_rate_request_done(&req);
2507
2508	/* restore the protection */
2509	clk_core_rate_restore_protect(core, cnt);
2510
2511	return ret ? 0 : req.rate;
2512}
2513
2514static int clk_core_set_rate_nolock(struct clk_core *core,
2515				    unsigned long req_rate)
2516{
2517	struct clk_core *top, *fail_clk;
2518	unsigned long rate;
2519	int ret;
2520
2521	if (!core)
2522		return 0;
2523
2524	rate = clk_core_req_round_rate_nolock(core, req_rate);
2525
2526	/* bail early if nothing to do */
2527	if (rate == clk_core_get_rate_nolock(core))
2528		return 0;
2529
2530	/* fail on a direct rate set of a protected provider */
2531	if (clk_core_rate_is_protected(core))
2532		return -EBUSY;
2533
2534	/* calculate new rates and get the topmost changed clock */
2535	top = clk_calc_new_rates(core, req_rate);
2536	if (!top)
2537		return -EINVAL;
2538
2539	ret = clk_pm_runtime_get(core);
2540	if (ret)
2541		return ret;
2542
2543	/* notify that we are about to change rates */
2544	fail_clk = clk_propagate_rate_change(top, PRE_RATE_CHANGE);
2545	if (fail_clk) {
2546		pr_debug("%s: failed to set %s rate\n", __func__,
2547				fail_clk->name);
2548		clk_propagate_rate_change(top, ABORT_RATE_CHANGE);
2549		ret = -EBUSY;
2550		goto err;
2551	}
2552
2553	/* change the rates */
2554	clk_change_rate(top);
2555
2556	core->req_rate = req_rate;
2557err:
2558	clk_pm_runtime_put(core);
2559
2560	return ret;
2561}
2562
2563/**
2564 * clk_set_rate - specify a new rate for clk
2565 * @clk: the clk whose rate is being changed
2566 * @rate: the new rate for clk
2567 *
2568 * In the simplest case clk_set_rate will only adjust the rate of clk.
2569 *
2570 * Setting the CLK_SET_RATE_PARENT flag allows the rate change operation to
2571 * propagate up to clk's parent; whether or not this happens depends on the
2572 * outcome of clk's .round_rate implementation.  If *parent_rate is unchanged
2573 * after calling .round_rate then upstream parent propagation is ignored.  If
2574 * *parent_rate comes back with a new rate for clk's parent then we propagate
2575 * up to clk's parent and set its rate.  Upward propagation will continue
2576 * until either a clk does not support the CLK_SET_RATE_PARENT flag or
2577 * .round_rate stops requesting changes to clk's parent_rate.
2578 *
2579 * Rate changes are accomplished via tree traversal that also recalculates the
2580 * rates for the clocks and fires off POST_RATE_CHANGE notifiers.
2581 *
2582 * Returns 0 on success, -EERROR otherwise.
2583 */
2584int clk_set_rate(struct clk *clk, unsigned long rate)
2585{
2586	int ret;
2587
2588	if (!clk)
2589		return 0;
2590
2591	/* prevent racing with updates to the clock topology */
2592	clk_prepare_lock();
2593
2594	if (clk->exclusive_count)
2595		clk_core_rate_unprotect(clk->core);
2596
2597	ret = clk_core_set_rate_nolock(clk->core, rate);
2598
2599	if (clk->exclusive_count)
2600		clk_core_rate_protect(clk->core);
2601
2602	clk_prepare_unlock();
2603
2604	return ret;
2605}
2606EXPORT_SYMBOL_GPL(clk_set_rate);
2607
2608/**
2609 * clk_set_rate_exclusive - specify a new rate and get exclusive control
2610 * @clk: the clk whose rate is being changed
2611 * @rate: the new rate for clk
2612 *
2613 * This is a combination of clk_set_rate() and clk_rate_exclusive_get()
2614 * within a critical section
2615 *
2616 * This can be used initially to ensure that at least 1 consumer is
2617 * satisfied when several consumers are competing for exclusivity over the
2618 * same clock provider.
2619 *
2620 * The exclusivity is not applied if setting the rate failed.
2621 *
2622 * Calls to clk_rate_exclusive_get() should be balanced with calls to
2623 * clk_rate_exclusive_put().
2624 *
2625 * Returns 0 on success, -EERROR otherwise.
2626 */
2627int clk_set_rate_exclusive(struct clk *clk, unsigned long rate)
2628{
2629	int ret;
2630
2631	if (!clk)
2632		return 0;
2633
2634	/* prevent racing with updates to the clock topology */
2635	clk_prepare_lock();
2636
2637	/*
2638	 * The temporary protection removal is not here, on purpose
2639	 * This function is meant to be used instead of clk_rate_protect,
2640	 * so before the consumer code path protect the clock provider
2641	 */
2642
2643	ret = clk_core_set_rate_nolock(clk->core, rate);
2644	if (!ret) {
2645		clk_core_rate_protect(clk->core);
2646		clk->exclusive_count++;
2647	}
2648
2649	clk_prepare_unlock();
2650
2651	return ret;
2652}
2653EXPORT_SYMBOL_GPL(clk_set_rate_exclusive);
2654
2655static int clk_set_rate_range_nolock(struct clk *clk,
2656				     unsigned long min,
2657				     unsigned long max)
2658{
2659	int ret = 0;
2660	unsigned long old_min, old_max, rate;
2661
2662	lockdep_assert_held(&prepare_lock);
2663
2664	if (!clk)
2665		return 0;
2666
2667	trace_clk_set_rate_range(clk->core, min, max);
2668
2669	if (min > max) {
2670		pr_err("%s: clk %s dev %s con %s: invalid range [%lu, %lu]\n",
2671		       __func__, clk->core->name, clk->dev_id, clk->con_id,
2672		       min, max);
2673		return -EINVAL;
2674	}
2675
2676	if (clk->exclusive_count)
2677		clk_core_rate_unprotect(clk->core);
2678
2679	/* Save the current values in case we need to rollback the change */
2680	old_min = clk->min_rate;
2681	old_max = clk->max_rate;
2682	clk->min_rate = min;
2683	clk->max_rate = max;
2684
2685	if (!clk_core_check_boundaries(clk->core, min, max)) {
2686		ret = -EINVAL;
2687		goto out;
2688	}
2689
2690	rate = clk->core->req_rate;
2691	if (clk->core->flags & CLK_GET_RATE_NOCACHE)
2692		rate = clk_core_get_rate_recalc(clk->core);
2693
2694	/*
2695	 * Since the boundaries have been changed, let's give the
2696	 * opportunity to the provider to adjust the clock rate based on
2697	 * the new boundaries.
2698	 *
2699	 * We also need to handle the case where the clock is currently
2700	 * outside of the boundaries. Clamping the last requested rate
2701	 * to the current minimum and maximum will also handle this.
2702	 *
2703	 * FIXME:
2704	 * There is a catch. It may fail for the usual reason (clock
2705	 * broken, clock protected, etc) but also because:
2706	 * - round_rate() was not favorable and fell on the wrong
2707	 *   side of the boundary
2708	 * - the determine_rate() callback does not really check for
2709	 *   this corner case when determining the rate
2710	 */
2711	rate = clamp(rate, min, max);
2712	ret = clk_core_set_rate_nolock(clk->core, rate);
2713	if (ret) {
2714		/* rollback the changes */
2715		clk->min_rate = old_min;
2716		clk->max_rate = old_max;
2717	}
2718
2719out:
2720	if (clk->exclusive_count)
2721		clk_core_rate_protect(clk->core);
2722
2723	return ret;
2724}
2725
2726/**
2727 * clk_set_rate_range - set a rate range for a clock source
2728 * @clk: clock source
2729 * @min: desired minimum clock rate in Hz, inclusive
2730 * @max: desired maximum clock rate in Hz, inclusive
2731 *
2732 * Return: 0 for success or negative errno on failure.
2733 */
2734int clk_set_rate_range(struct clk *clk, unsigned long min, unsigned long max)
2735{
2736	int ret;
2737
2738	if (!clk)
2739		return 0;
2740
2741	clk_prepare_lock();
2742
2743	ret = clk_set_rate_range_nolock(clk, min, max);
2744
2745	clk_prepare_unlock();
2746
2747	return ret;
2748}
2749EXPORT_SYMBOL_GPL(clk_set_rate_range);
2750
2751/**
2752 * clk_set_min_rate - set a minimum clock rate for a clock source
2753 * @clk: clock source
2754 * @rate: desired minimum clock rate in Hz, inclusive
2755 *
2756 * Returns success (0) or negative errno.
2757 */
2758int clk_set_min_rate(struct clk *clk, unsigned long rate)
2759{
2760	if (!clk)
2761		return 0;
2762
2763	trace_clk_set_min_rate(clk->core, rate);
2764
2765	return clk_set_rate_range(clk, rate, clk->max_rate);
2766}
2767EXPORT_SYMBOL_GPL(clk_set_min_rate);
2768
2769/**
2770 * clk_set_max_rate - set a maximum clock rate for a clock source
2771 * @clk: clock source
2772 * @rate: desired maximum clock rate in Hz, inclusive
2773 *
2774 * Returns success (0) or negative errno.
2775 */
2776int clk_set_max_rate(struct clk *clk, unsigned long rate)
2777{
2778	if (!clk)
2779		return 0;
2780
2781	trace_clk_set_max_rate(clk->core, rate);
2782
2783	return clk_set_rate_range(clk, clk->min_rate, rate);
2784}
2785EXPORT_SYMBOL_GPL(clk_set_max_rate);
2786
2787/**
2788 * clk_get_parent - return the parent of a clk
2789 * @clk: the clk whose parent gets returned
2790 *
2791 * Simply returns clk->parent.  Returns NULL if clk is NULL.
2792 */
2793struct clk *clk_get_parent(struct clk *clk)
2794{
2795	struct clk *parent;
2796
2797	if (!clk)
2798		return NULL;
2799
2800	clk_prepare_lock();
2801	/* TODO: Create a per-user clk and change callers to call clk_put */
2802	parent = !clk->core->parent ? NULL : clk->core->parent->hw->clk;
2803	clk_prepare_unlock();
2804
2805	return parent;
2806}
2807EXPORT_SYMBOL_GPL(clk_get_parent);
2808
2809static struct clk_core *__clk_init_parent(struct clk_core *core)
2810{
2811	u8 index = 0;
2812
2813	if (core->num_parents > 1 && core->ops->get_parent)
2814		index = core->ops->get_parent(core->hw);
2815
2816	return clk_core_get_parent_by_index(core, index);
2817}
2818
2819static void clk_core_reparent(struct clk_core *core,
2820				  struct clk_core *new_parent)
2821{
2822	clk_reparent(core, new_parent);
2823	__clk_recalc_accuracies(core);
2824	__clk_recalc_rates(core, true, POST_RATE_CHANGE);
2825}
2826
2827void clk_hw_reparent(struct clk_hw *hw, struct clk_hw *new_parent)
2828{
2829	if (!hw)
2830		return;
2831
2832	clk_core_reparent(hw->core, !new_parent ? NULL : new_parent->core);
2833}
2834
2835/**
2836 * clk_has_parent - check if a clock is a possible parent for another
2837 * @clk: clock source
2838 * @parent: parent clock source
2839 *
2840 * This function can be used in drivers that need to check that a clock can be
2841 * the parent of another without actually changing the parent.
2842 *
2843 * Returns true if @parent is a possible parent for @clk, false otherwise.
2844 */
2845bool clk_has_parent(const struct clk *clk, const struct clk *parent)
2846{
2847	/* NULL clocks should be nops, so return success if either is NULL. */
2848	if (!clk || !parent)
2849		return true;
2850
2851	return clk_core_has_parent(clk->core, parent->core);
2852}
2853EXPORT_SYMBOL_GPL(clk_has_parent);
2854
2855static int clk_core_set_parent_nolock(struct clk_core *core,
2856				      struct clk_core *parent)
2857{
2858	int ret = 0;
2859	int p_index = 0;
2860	unsigned long p_rate = 0;
2861
2862	lockdep_assert_held(&prepare_lock);
2863
2864	if (!core)
2865		return 0;
2866
2867	if (core->parent == parent)
2868		return 0;
2869
2870	/* verify ops for multi-parent clks */
2871	if (core->num_parents > 1 && !core->ops->set_parent)
2872		return -EPERM;
2873
2874	/* check that we are allowed to re-parent if the clock is in use */
2875	if ((core->flags & CLK_SET_PARENT_GATE) && core->prepare_count)
2876		return -EBUSY;
2877
2878	if (clk_core_rate_is_protected(core))
2879		return -EBUSY;
2880
2881	/* try finding the new parent index */
2882	if (parent) {
2883		p_index = clk_fetch_parent_index(core, parent);
2884		if (p_index < 0) {
2885			pr_debug("%s: clk %s can not be parent of clk %s\n",
2886					__func__, parent->name, core->name);
2887			return p_index;
2888		}
2889		p_rate = parent->rate;
2890	}
2891
2892	ret = clk_pm_runtime_get(core);
2893	if (ret)
2894		return ret;
2895
2896	/* propagate PRE_RATE_CHANGE notifications */
2897	ret = __clk_speculate_rates(core, p_rate);
2898
2899	/* abort if a driver objects */
2900	if (ret & NOTIFY_STOP_MASK)
2901		goto runtime_put;
2902
2903	/* do the re-parent */
2904	ret = __clk_set_parent(core, parent, p_index);
2905
2906	/* propagate rate an accuracy recalculation accordingly */
2907	if (ret) {
2908		__clk_recalc_rates(core, true, ABORT_RATE_CHANGE);
2909	} else {
2910		__clk_recalc_rates(core, true, POST_RATE_CHANGE);
2911		__clk_recalc_accuracies(core);
2912	}
2913
2914runtime_put:
2915	clk_pm_runtime_put(core);
2916
2917	return ret;
2918}
2919
2920int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
2921{
2922	return clk_core_set_parent_nolock(hw->core, parent->core);
2923}
2924EXPORT_SYMBOL_GPL(clk_hw_set_parent);
2925
2926/**
2927 * clk_set_parent - switch the parent of a mux clk
2928 * @clk: the mux clk whose input we are switching
2929 * @parent: the new input to clk
2930 *
2931 * Re-parent clk to use parent as its new input source.  If clk is in
2932 * prepared state, the clk will get enabled for the duration of this call. If
2933 * that's not acceptable for a specific clk (Eg: the consumer can't handle
2934 * that, the reparenting is glitchy in hardware, etc), use the
2935 * CLK_SET_PARENT_GATE flag to allow reparenting only when clk is unprepared.
2936 *
2937 * After successfully changing clk's parent clk_set_parent will update the
2938 * clk topology, sysfs topology and propagate rate recalculation via
2939 * __clk_recalc_rates.
2940 *
2941 * Returns 0 on success, -EERROR otherwise.
2942 */
2943int clk_set_parent(struct clk *clk, struct clk *parent)
2944{
2945	int ret;
2946
2947	if (!clk)
2948		return 0;
2949
2950	clk_prepare_lock();
2951
2952	if (clk->exclusive_count)
2953		clk_core_rate_unprotect(clk->core);
2954
2955	ret = clk_core_set_parent_nolock(clk->core,
2956					 parent ? parent->core : NULL);
2957
2958	if (clk->exclusive_count)
2959		clk_core_rate_protect(clk->core);
2960
2961	clk_prepare_unlock();
2962
2963	return ret;
2964}
2965EXPORT_SYMBOL_GPL(clk_set_parent);
2966
2967static int clk_core_set_phase_nolock(struct clk_core *core, int degrees)
2968{
2969	int ret = -EINVAL;
2970
2971	lockdep_assert_held(&prepare_lock);
2972
2973	if (!core)
2974		return 0;
2975
2976	if (clk_core_rate_is_protected(core))
2977		return -EBUSY;
2978
2979	trace_clk_set_phase(core, degrees);
2980
2981	if (core->ops->set_phase) {
2982		ret = core->ops->set_phase(core->hw, degrees);
2983		if (!ret)
2984			core->phase = degrees;
2985	}
2986
2987	trace_clk_set_phase_complete(core, degrees);
2988
2989	return ret;
2990}
2991
2992/**
2993 * clk_set_phase - adjust the phase shift of a clock signal
2994 * @clk: clock signal source
2995 * @degrees: number of degrees the signal is shifted
2996 *
2997 * Shifts the phase of a clock signal by the specified
2998 * degrees. Returns 0 on success, -EERROR otherwise.
2999 *
3000 * This function makes no distinction about the input or reference
3001 * signal that we adjust the clock signal phase against. For example
3002 * phase locked-loop clock signal generators we may shift phase with
3003 * respect to feedback clock signal input, but for other cases the
3004 * clock phase may be shifted with respect to some other, unspecified
3005 * signal.
3006 *
3007 * Additionally the concept of phase shift does not propagate through
3008 * the clock tree hierarchy, which sets it apart from clock rates and
3009 * clock accuracy. A parent clock phase attribute does not have an
3010 * impact on the phase attribute of a child clock.
3011 */
3012int clk_set_phase(struct clk *clk, int degrees)
3013{
3014	int ret;
3015
3016	if (!clk)
3017		return 0;
3018
3019	/* sanity check degrees */
3020	degrees %= 360;
3021	if (degrees < 0)
3022		degrees += 360;
3023
3024	clk_prepare_lock();
3025
3026	if (clk->exclusive_count)
3027		clk_core_rate_unprotect(clk->core);
3028
3029	ret = clk_core_set_phase_nolock(clk->core, degrees);
3030
3031	if (clk->exclusive_count)
3032		clk_core_rate_protect(clk->core);
3033
3034	clk_prepare_unlock();
3035
3036	return ret;
3037}
3038EXPORT_SYMBOL_GPL(clk_set_phase);
3039
3040static int clk_core_get_phase(struct clk_core *core)
3041{
3042	int ret;
3043
3044	lockdep_assert_held(&prepare_lock);
3045	if (!core->ops->get_phase)
3046		return 0;
3047
3048	/* Always try to update cached phase if possible */
3049	ret = core->ops->get_phase(core->hw);
3050	if (ret >= 0)
3051		core->phase = ret;
3052
3053	return ret;
3054}
3055
3056/**
3057 * clk_get_phase - return the phase shift of a clock signal
3058 * @clk: clock signal source
3059 *
3060 * Returns the phase shift of a clock node in degrees, otherwise returns
3061 * -EERROR.
3062 */
3063int clk_get_phase(struct clk *clk)
3064{
3065	int ret;
3066
3067	if (!clk)
3068		return 0;
3069
3070	clk_prepare_lock();
3071	ret = clk_core_get_phase(clk->core);
3072	clk_prepare_unlock();
3073
3074	return ret;
3075}
3076EXPORT_SYMBOL_GPL(clk_get_phase);
3077
3078static void clk_core_reset_duty_cycle_nolock(struct clk_core *core)
3079{
3080	/* Assume a default value of 50% */
3081	core->duty.num = 1;
3082	core->duty.den = 2;
3083}
3084
3085static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core);
3086
3087static int clk_core_update_duty_cycle_nolock(struct clk_core *core)
3088{
3089	struct clk_duty *duty = &core->duty;
3090	int ret = 0;
3091
3092	if (!core->ops->get_duty_cycle)
3093		return clk_core_update_duty_cycle_parent_nolock(core);
3094
3095	ret = core->ops->get_duty_cycle(core->hw, duty);
3096	if (ret)
3097		goto reset;
3098
3099	/* Don't trust the clock provider too much */
3100	if (duty->den == 0 || duty->num > duty->den) {
3101		ret = -EINVAL;
3102		goto reset;
3103	}
3104
3105	return 0;
3106
3107reset:
3108	clk_core_reset_duty_cycle_nolock(core);
3109	return ret;
3110}
3111
3112static int clk_core_update_duty_cycle_parent_nolock(struct clk_core *core)
3113{
3114	int ret = 0;
3115
3116	if (core->parent &&
3117	    core->flags & CLK_DUTY_CYCLE_PARENT) {
3118		ret = clk_core_update_duty_cycle_nolock(core->parent);
3119		memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3120	} else {
3121		clk_core_reset_duty_cycle_nolock(core);
3122	}
3123
3124	return ret;
3125}
3126
3127static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3128						 struct clk_duty *duty);
3129
3130static int clk_core_set_duty_cycle_nolock(struct clk_core *core,
3131					  struct clk_duty *duty)
3132{
3133	int ret;
3134
3135	lockdep_assert_held(&prepare_lock);
3136
3137	if (clk_core_rate_is_protected(core))
3138		return -EBUSY;
3139
3140	trace_clk_set_duty_cycle(core, duty);
3141
3142	if (!core->ops->set_duty_cycle)
3143		return clk_core_set_duty_cycle_parent_nolock(core, duty);
3144
3145	ret = core->ops->set_duty_cycle(core->hw, duty);
3146	if (!ret)
3147		memcpy(&core->duty, duty, sizeof(*duty));
3148
3149	trace_clk_set_duty_cycle_complete(core, duty);
3150
3151	return ret;
3152}
3153
3154static int clk_core_set_duty_cycle_parent_nolock(struct clk_core *core,
3155						 struct clk_duty *duty)
3156{
3157	int ret = 0;
3158
3159	if (core->parent &&
3160	    core->flags & (CLK_DUTY_CYCLE_PARENT | CLK_SET_RATE_PARENT)) {
3161		ret = clk_core_set_duty_cycle_nolock(core->parent, duty);
3162		memcpy(&core->duty, &core->parent->duty, sizeof(core->duty));
3163	}
3164
3165	return ret;
3166}
3167
3168/**
3169 * clk_set_duty_cycle - adjust the duty cycle ratio of a clock signal
3170 * @clk: clock signal source
3171 * @num: numerator of the duty cycle ratio to be applied
3172 * @den: denominator of the duty cycle ratio to be applied
3173 *
3174 * Apply the duty cycle ratio if the ratio is valid and the clock can
3175 * perform this operation
3176 *
3177 * Returns (0) on success, a negative errno otherwise.
3178 */
3179int clk_set_duty_cycle(struct clk *clk, unsigned int num, unsigned int den)
3180{
3181	int ret;
3182	struct clk_duty duty;
3183
3184	if (!clk)
3185		return 0;
3186
3187	/* sanity check the ratio */
3188	if (den == 0 || num > den)
3189		return -EINVAL;
3190
3191	duty.num = num;
3192	duty.den = den;
3193
3194	clk_prepare_lock();
3195
3196	if (clk->exclusive_count)
3197		clk_core_rate_unprotect(clk->core);
3198
3199	ret = clk_core_set_duty_cycle_nolock(clk->core, &duty);
3200
3201	if (clk->exclusive_count)
3202		clk_core_rate_protect(clk->core);
3203
3204	clk_prepare_unlock();
3205
3206	return ret;
3207}
3208EXPORT_SYMBOL_GPL(clk_set_duty_cycle);
3209
3210static int clk_core_get_scaled_duty_cycle(struct clk_core *core,
3211					  unsigned int scale)
3212{
3213	struct clk_duty *duty = &core->duty;
3214	int ret;
3215
3216	clk_prepare_lock();
3217
3218	ret = clk_core_update_duty_cycle_nolock(core);
3219	if (!ret)
3220		ret = mult_frac(scale, duty->num, duty->den);
3221
3222	clk_prepare_unlock();
3223
3224	return ret;
3225}
3226
3227/**
3228 * clk_get_scaled_duty_cycle - return the duty cycle ratio of a clock signal
3229 * @clk: clock signal source
3230 * @scale: scaling factor to be applied to represent the ratio as an integer
3231 *
3232 * Returns the duty cycle ratio of a clock node multiplied by the provided
3233 * scaling factor, or negative errno on error.
3234 */
3235int clk_get_scaled_duty_cycle(struct clk *clk, unsigned int scale)
3236{
3237	if (!clk)
3238		return 0;
3239
3240	return clk_core_get_scaled_duty_cycle(clk->core, scale);
3241}
3242EXPORT_SYMBOL_GPL(clk_get_scaled_duty_cycle);
3243
3244/**
3245 * clk_is_match - check if two clk's point to the same hardware clock
3246 * @p: clk compared against q
3247 * @q: clk compared against p
3248 *
3249 * Returns true if the two struct clk pointers both point to the same hardware
3250 * clock node. Put differently, returns true if struct clk *p and struct clk *q
3251 * share the same struct clk_core object.
3252 *
3253 * Returns false otherwise. Note that two NULL clks are treated as matching.
3254 */
3255bool clk_is_match(const struct clk *p, const struct clk *q)
3256{
3257	/* trivial case: identical struct clk's or both NULL */
3258	if (p == q)
3259		return true;
3260
3261	/* true if clk->core pointers match. Avoid dereferencing garbage */
3262	if (!IS_ERR_OR_NULL(p) && !IS_ERR_OR_NULL(q))
3263		if (p->core == q->core)
3264			return true;
3265
3266	return false;
3267}
3268EXPORT_SYMBOL_GPL(clk_is_match);
3269
3270/***        debugfs support        ***/
3271
3272#ifdef CONFIG_DEBUG_FS
3273#include <linux/debugfs.h>
3274
3275static struct dentry *rootdir;
3276static int inited = 0;
3277static DEFINE_MUTEX(clk_debug_lock);
3278static HLIST_HEAD(clk_debug_list);
3279
3280static struct hlist_head *orphan_list[] = {
3281	&clk_orphan_list,
3282	NULL,
3283};
3284
3285static void clk_summary_show_one(struct seq_file *s, struct clk_core *c,
3286				 int level)
3287{
3288	int phase;
3289	struct clk *clk_user;
3290	int multi_node = 0;
3291
3292	seq_printf(s, "%*s%-*s %-7d %-8d %-8d %-11lu %-10lu ",
3293		   level * 3 + 1, "",
3294		   35 - level * 3, c->name,
3295		   c->enable_count, c->prepare_count, c->protect_count,
3296		   clk_core_get_rate_recalc(c),
3297		   clk_core_get_accuracy_recalc(c));
3298
3299	phase = clk_core_get_phase(c);
3300	if (phase >= 0)
3301		seq_printf(s, "%-5d", phase);
3302	else
3303		seq_puts(s, "-----");
3304
3305	seq_printf(s, " %-6d", clk_core_get_scaled_duty_cycle(c, 100000));
3306
3307	if (c->ops->is_enabled)
3308		seq_printf(s, " %5c ", clk_core_is_enabled(c) ? 'Y' : 'N');
3309	else if (!c->ops->enable)
3310		seq_printf(s, " %5c ", 'Y');
3311	else
3312		seq_printf(s, " %5c ", '?');
3313
3314	hlist_for_each_entry(clk_user, &c->clks, clks_node) {
3315		seq_printf(s, "%*s%-*s  %-25s\n",
3316			   level * 3 + 2 + 105 * multi_node, "",
3317			   30,
3318			   clk_user->dev_id ? clk_user->dev_id : "deviceless",
3319			   clk_user->con_id ? clk_user->con_id : "no_connection_id");
3320
3321		multi_node = 1;
3322	}
3323
3324}
3325
3326static void clk_summary_show_subtree(struct seq_file *s, struct clk_core *c,
3327				     int level)
3328{
3329	struct clk_core *child;
3330
3331	clk_summary_show_one(s, c, level);
3332
3333	hlist_for_each_entry(child, &c->children, child_node)
3334		clk_summary_show_subtree(s, child, level + 1);
3335}
3336
3337static int clk_summary_show(struct seq_file *s, void *data)
3338{
3339	struct clk_core *c;
3340	struct hlist_head **lists = s->private;
3341	int ret;
3342
3343	seq_puts(s, "                                 enable  prepare  protect                                duty  hardware                            connection\n");
3344	seq_puts(s, "   clock                          count    count    count        rate   accuracy phase  cycle    enable   consumer                         id\n");
3345	seq_puts(s, "---------------------------------------------------------------------------------------------------------------------------------------------\n");
3346
3347	ret = clk_pm_runtime_get_all();
3348	if (ret)
3349		return ret;
3350
3351	clk_prepare_lock();
3352
3353	for (; *lists; lists++)
3354		hlist_for_each_entry(c, *lists, child_node)
3355			clk_summary_show_subtree(s, c, 0);
3356
3357	clk_prepare_unlock();
3358	clk_pm_runtime_put_all();
3359
3360	return 0;
3361}
3362DEFINE_SHOW_ATTRIBUTE(clk_summary);
3363
3364static void clk_dump_one(struct seq_file *s, struct clk_core *c, int level)
3365{
3366	int phase;
3367	unsigned long min_rate, max_rate;
3368
3369	clk_core_get_boundaries(c, &min_rate, &max_rate);
3370
3371	/* This should be JSON format, i.e. elements separated with a comma */
3372	seq_printf(s, "\"%s\": { ", c->name);
3373	seq_printf(s, "\"enable_count\": %d,", c->enable_count);
3374	seq_printf(s, "\"prepare_count\": %d,", c->prepare_count);
3375	seq_printf(s, "\"protect_count\": %d,", c->protect_count);
3376	seq_printf(s, "\"rate\": %lu,", clk_core_get_rate_recalc(c));
3377	seq_printf(s, "\"min_rate\": %lu,", min_rate);
3378	seq_printf(s, "\"max_rate\": %lu,", max_rate);
3379	seq_printf(s, "\"accuracy\": %lu,", clk_core_get_accuracy_recalc(c));
3380	phase = clk_core_get_phase(c);
3381	if (phase >= 0)
3382		seq_printf(s, "\"phase\": %d,", phase);
3383	seq_printf(s, "\"duty_cycle\": %u",
3384		   clk_core_get_scaled_duty_cycle(c, 100000));
3385}
3386
3387static void clk_dump_subtree(struct seq_file *s, struct clk_core *c, int level)
3388{
3389	struct clk_core *child;
3390
3391	clk_dump_one(s, c, level);
3392
3393	hlist_for_each_entry(child, &c->children, child_node) {
3394		seq_putc(s, ',');
3395		clk_dump_subtree(s, child, level + 1);
3396	}
3397
3398	seq_putc(s, '}');
3399}
3400
3401static int clk_dump_show(struct seq_file *s, void *data)
3402{
3403	struct clk_core *c;
3404	bool first_node = true;
3405	struct hlist_head **lists = s->private;
3406	int ret;
3407
3408	ret = clk_pm_runtime_get_all();
3409	if (ret)
3410		return ret;
3411
3412	seq_putc(s, '{');
3413
3414	clk_prepare_lock();
3415
3416	for (; *lists; lists++) {
3417		hlist_for_each_entry(c, *lists, child_node) {
3418			if (!first_node)
3419				seq_putc(s, ',');
3420			first_node = false;
3421			clk_dump_subtree(s, c, 0);
3422		}
3423	}
3424
3425	clk_prepare_unlock();
3426	clk_pm_runtime_put_all();
3427
3428	seq_puts(s, "}\n");
3429	return 0;
3430}
3431DEFINE_SHOW_ATTRIBUTE(clk_dump);
3432
3433#undef CLOCK_ALLOW_WRITE_DEBUGFS
3434#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3435/*
3436 * This can be dangerous, therefore don't provide any real compile time
3437 * configuration option for this feature.
3438 * People who want to use this will need to modify the source code directly.
3439 */
3440static int clk_rate_set(void *data, u64 val)
3441{
3442	struct clk_core *core = data;
3443	int ret;
3444
3445	clk_prepare_lock();
3446	ret = clk_core_set_rate_nolock(core, val);
3447	clk_prepare_unlock();
3448
3449	return ret;
3450}
3451
3452#define clk_rate_mode	0644
3453
3454static int clk_phase_set(void *data, u64 val)
3455{
3456	struct clk_core *core = data;
3457	int degrees = do_div(val, 360);
3458	int ret;
3459
3460	clk_prepare_lock();
3461	ret = clk_core_set_phase_nolock(core, degrees);
3462	clk_prepare_unlock();
3463
3464	return ret;
3465}
3466
3467#define clk_phase_mode	0644
3468
3469static int clk_prepare_enable_set(void *data, u64 val)
3470{
3471	struct clk_core *core = data;
3472	int ret = 0;
3473
3474	if (val)
3475		ret = clk_prepare_enable(core->hw->clk);
3476	else
3477		clk_disable_unprepare(core->hw->clk);
3478
3479	return ret;
3480}
3481
3482static int clk_prepare_enable_get(void *data, u64 *val)
3483{
3484	struct clk_core *core = data;
3485
3486	*val = core->enable_count && core->prepare_count;
3487	return 0;
3488}
3489
3490DEFINE_DEBUGFS_ATTRIBUTE(clk_prepare_enable_fops, clk_prepare_enable_get,
3491			 clk_prepare_enable_set, "%llu\n");
3492
3493#else
3494#define clk_rate_set	NULL
3495#define clk_rate_mode	0444
3496
3497#define clk_phase_set	NULL
3498#define clk_phase_mode	0644
3499#endif
3500
3501static int clk_rate_get(void *data, u64 *val)
3502{
3503	struct clk_core *core = data;
3504
3505	clk_prepare_lock();
3506	*val = clk_core_get_rate_recalc(core);
3507	clk_prepare_unlock();
3508
3509	return 0;
3510}
3511
3512DEFINE_DEBUGFS_ATTRIBUTE(clk_rate_fops, clk_rate_get, clk_rate_set, "%llu\n");
3513
3514static int clk_phase_get(void *data, u64 *val)
3515{
3516	struct clk_core *core = data;
3517
3518	*val = core->phase;
3519	return 0;
3520}
3521
3522DEFINE_DEBUGFS_ATTRIBUTE(clk_phase_fops, clk_phase_get, clk_phase_set, "%llu\n");
3523
3524static const struct {
3525	unsigned long flag;
3526	const char *name;
3527} clk_flags[] = {
3528#define ENTRY(f) { f, #f }
3529	ENTRY(CLK_SET_RATE_GATE),
3530	ENTRY(CLK_SET_PARENT_GATE),
3531	ENTRY(CLK_SET_RATE_PARENT),
3532	ENTRY(CLK_IGNORE_UNUSED),
3533	ENTRY(CLK_GET_RATE_NOCACHE),
3534	ENTRY(CLK_SET_RATE_NO_REPARENT),
3535	ENTRY(CLK_GET_ACCURACY_NOCACHE),
3536	ENTRY(CLK_RECALC_NEW_RATES),
3537	ENTRY(CLK_SET_RATE_UNGATE),
3538	ENTRY(CLK_IS_CRITICAL),
3539	ENTRY(CLK_OPS_PARENT_ENABLE),
3540	ENTRY(CLK_DUTY_CYCLE_PARENT),
3541#undef ENTRY
3542};
3543
3544static int clk_flags_show(struct seq_file *s, void *data)
3545{
3546	struct clk_core *core = s->private;
3547	unsigned long flags = core->flags;
3548	unsigned int i;
3549
3550	for (i = 0; flags && i < ARRAY_SIZE(clk_flags); i++) {
3551		if (flags & clk_flags[i].flag) {
3552			seq_printf(s, "%s\n", clk_flags[i].name);
3553			flags &= ~clk_flags[i].flag;
3554		}
3555	}
3556	if (flags) {
3557		/* Unknown flags */
3558		seq_printf(s, "0x%lx\n", flags);
3559	}
3560
3561	return 0;
3562}
3563DEFINE_SHOW_ATTRIBUTE(clk_flags);
3564
3565static void possible_parent_show(struct seq_file *s, struct clk_core *core,
3566				 unsigned int i, char terminator)
3567{
3568	struct clk_core *parent;
3569	const char *name = NULL;
3570
3571	/*
3572	 * Go through the following options to fetch a parent's name.
3573	 *
3574	 * 1. Fetch the registered parent clock and use its name
3575	 * 2. Use the global (fallback) name if specified
3576	 * 3. Use the local fw_name if provided
3577	 * 4. Fetch parent clock's clock-output-name if DT index was set
3578	 *
3579	 * This may still fail in some cases, such as when the parent is
3580	 * specified directly via a struct clk_hw pointer, but it isn't
3581	 * registered (yet).
3582	 */
3583	parent = clk_core_get_parent_by_index(core, i);
3584	if (parent) {
3585		seq_puts(s, parent->name);
3586	} else if (core->parents[i].name) {
3587		seq_puts(s, core->parents[i].name);
3588	} else if (core->parents[i].fw_name) {
3589		seq_printf(s, "<%s>(fw)", core->parents[i].fw_name);
3590	} else {
3591		if (core->parents[i].index >= 0)
3592			name = of_clk_get_parent_name(core->of_node, core->parents[i].index);
3593		if (!name)
3594			name = "(missing)";
3595
3596		seq_puts(s, name);
3597	}
3598
3599	seq_putc(s, terminator);
3600}
3601
3602static int possible_parents_show(struct seq_file *s, void *data)
3603{
3604	struct clk_core *core = s->private;
3605	int i;
3606
3607	for (i = 0; i < core->num_parents - 1; i++)
3608		possible_parent_show(s, core, i, ' ');
3609
3610	possible_parent_show(s, core, i, '\n');
3611
3612	return 0;
3613}
3614DEFINE_SHOW_ATTRIBUTE(possible_parents);
3615
3616static int current_parent_show(struct seq_file *s, void *data)
3617{
3618	struct clk_core *core = s->private;
3619
3620	if (core->parent)
3621		seq_printf(s, "%s\n", core->parent->name);
3622
3623	return 0;
3624}
3625DEFINE_SHOW_ATTRIBUTE(current_parent);
3626
3627#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3628static ssize_t current_parent_write(struct file *file, const char __user *ubuf,
3629				    size_t count, loff_t *ppos)
3630{
3631	struct seq_file *s = file->private_data;
3632	struct clk_core *core = s->private;
3633	struct clk_core *parent;
3634	u8 idx;
3635	int err;
3636
3637	err = kstrtou8_from_user(ubuf, count, 0, &idx);
3638	if (err < 0)
3639		return err;
3640
3641	parent = clk_core_get_parent_by_index(core, idx);
3642	if (!parent)
3643		return -ENOENT;
3644
3645	clk_prepare_lock();
3646	err = clk_core_set_parent_nolock(core, parent);
3647	clk_prepare_unlock();
3648	if (err)
3649		return err;
3650
3651	return count;
3652}
3653
3654static const struct file_operations current_parent_rw_fops = {
3655	.open		= current_parent_open,
3656	.write		= current_parent_write,
3657	.read		= seq_read,
3658	.llseek		= seq_lseek,
3659	.release	= single_release,
3660};
3661#endif
3662
3663static int clk_duty_cycle_show(struct seq_file *s, void *data)
3664{
3665	struct clk_core *core = s->private;
3666	struct clk_duty *duty = &core->duty;
3667
3668	seq_printf(s, "%u/%u\n", duty->num, duty->den);
3669
3670	return 0;
3671}
3672DEFINE_SHOW_ATTRIBUTE(clk_duty_cycle);
3673
3674static int clk_min_rate_show(struct seq_file *s, void *data)
3675{
3676	struct clk_core *core = s->private;
3677	unsigned long min_rate, max_rate;
3678
3679	clk_prepare_lock();
3680	clk_core_get_boundaries(core, &min_rate, &max_rate);
3681	clk_prepare_unlock();
3682	seq_printf(s, "%lu\n", min_rate);
3683
3684	return 0;
3685}
3686DEFINE_SHOW_ATTRIBUTE(clk_min_rate);
3687
3688static int clk_max_rate_show(struct seq_file *s, void *data)
3689{
3690	struct clk_core *core = s->private;
3691	unsigned long min_rate, max_rate;
3692
3693	clk_prepare_lock();
3694	clk_core_get_boundaries(core, &min_rate, &max_rate);
3695	clk_prepare_unlock();
3696	seq_printf(s, "%lu\n", max_rate);
3697
3698	return 0;
3699}
3700DEFINE_SHOW_ATTRIBUTE(clk_max_rate);
3701
3702static void clk_debug_create_one(struct clk_core *core, struct dentry *pdentry)
3703{
3704	struct dentry *root;
3705
3706	if (!core || !pdentry)
3707		return;
3708
3709	root = debugfs_create_dir(core->name, pdentry);
3710	core->dentry = root;
3711
3712	debugfs_create_file("clk_rate", clk_rate_mode, root, core,
3713			    &clk_rate_fops);
3714	debugfs_create_file("clk_min_rate", 0444, root, core, &clk_min_rate_fops);
3715	debugfs_create_file("clk_max_rate", 0444, root, core, &clk_max_rate_fops);
3716	debugfs_create_ulong("clk_accuracy", 0444, root, &core->accuracy);
3717	debugfs_create_file("clk_phase", clk_phase_mode, root, core,
3718			    &clk_phase_fops);
3719	debugfs_create_file("clk_flags", 0444, root, core, &clk_flags_fops);
3720	debugfs_create_u32("clk_prepare_count", 0444, root, &core->prepare_count);
3721	debugfs_create_u32("clk_enable_count", 0444, root, &core->enable_count);
3722	debugfs_create_u32("clk_protect_count", 0444, root, &core->protect_count);
3723	debugfs_create_u32("clk_notifier_count", 0444, root, &core->notifier_count);
3724	debugfs_create_file("clk_duty_cycle", 0444, root, core,
3725			    &clk_duty_cycle_fops);
3726#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3727	debugfs_create_file("clk_prepare_enable", 0644, root, core,
3728			    &clk_prepare_enable_fops);
3729
3730	if (core->num_parents > 1)
3731		debugfs_create_file("clk_parent", 0644, root, core,
3732				    &current_parent_rw_fops);
3733	else
3734#endif
3735	if (core->num_parents > 0)
3736		debugfs_create_file("clk_parent", 0444, root, core,
3737				    &current_parent_fops);
3738
3739	if (core->num_parents > 1)
3740		debugfs_create_file("clk_possible_parents", 0444, root, core,
3741				    &possible_parents_fops);
3742
3743	if (core->ops->debug_init)
3744		core->ops->debug_init(core->hw, core->dentry);
3745}
3746
3747/**
3748 * clk_debug_register - add a clk node to the debugfs clk directory
3749 * @core: the clk being added to the debugfs clk directory
3750 *
3751 * Dynamically adds a clk to the debugfs clk directory if debugfs has been
3752 * initialized.  Otherwise it bails out early since the debugfs clk directory
3753 * will be created lazily by clk_debug_init as part of a late_initcall.
3754 */
3755static void clk_debug_register(struct clk_core *core)
3756{
3757	mutex_lock(&clk_debug_lock);
3758	hlist_add_head(&core->debug_node, &clk_debug_list);
3759	if (inited)
3760		clk_debug_create_one(core, rootdir);
3761	mutex_unlock(&clk_debug_lock);
3762}
3763
3764 /**
3765 * clk_debug_unregister - remove a clk node from the debugfs clk directory
3766 * @core: the clk being removed from the debugfs clk directory
3767 *
3768 * Dynamically removes a clk and all its child nodes from the
3769 * debugfs clk directory if clk->dentry points to debugfs created by
3770 * clk_debug_register in __clk_core_init.
3771 */
3772static void clk_debug_unregister(struct clk_core *core)
3773{
3774	mutex_lock(&clk_debug_lock);
3775	hlist_del_init(&core->debug_node);
3776	debugfs_remove_recursive(core->dentry);
3777	core->dentry = NULL;
3778	mutex_unlock(&clk_debug_lock);
3779}
3780
3781/**
3782 * clk_debug_init - lazily populate the debugfs clk directory
3783 *
3784 * clks are often initialized very early during boot before memory can be
3785 * dynamically allocated and well before debugfs is setup. This function
3786 * populates the debugfs clk directory once at boot-time when we know that
3787 * debugfs is setup. It should only be called once at boot-time, all other clks
3788 * added dynamically will be done so with clk_debug_register.
3789 */
3790static int __init clk_debug_init(void)
3791{
3792	struct clk_core *core;
3793
3794#ifdef CLOCK_ALLOW_WRITE_DEBUGFS
3795	pr_warn("\n");
3796	pr_warn("********************************************************************\n");
3797	pr_warn("**     NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE           **\n");
3798	pr_warn("**                                                                **\n");
3799	pr_warn("**  WRITEABLE clk DebugFS SUPPORT HAS BEEN ENABLED IN THIS KERNEL **\n");
3800	pr_warn("**                                                                **\n");
3801	pr_warn("** This means that this kernel is built to expose clk operations  **\n");
3802	pr_warn("** such as parent or rate setting, enabling, disabling, etc.      **\n");
3803	pr_warn("** to userspace, which may compromise security on your system.    **\n");
3804	pr_warn("**                                                                **\n");
3805	pr_warn("** If you see this message and you are not debugging the          **\n");
3806	pr_warn("** kernel, report this immediately to your vendor!                **\n");
3807	pr_warn("**                                                                **\n");
3808	pr_warn("**     NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE           **\n");
3809	pr_warn("********************************************************************\n");
3810#endif
3811
3812	rootdir = debugfs_create_dir("clk", NULL);
3813
3814	debugfs_create_file("clk_summary", 0444, rootdir, &all_lists,
3815			    &clk_summary_fops);
3816	debugfs_create_file("clk_dump", 0444, rootdir, &all_lists,
3817			    &clk_dump_fops);
3818	debugfs_create_file("clk_orphan_summary", 0444, rootdir, &orphan_list,
3819			    &clk_summary_fops);
3820	debugfs_create_file("clk_orphan_dump", 0444, rootdir, &orphan_list,
3821			    &clk_dump_fops);
3822
3823	mutex_lock(&clk_debug_lock);
3824	hlist_for_each_entry(core, &clk_debug_list, debug_node)
3825		clk_debug_create_one(core, rootdir);
3826
3827	inited = 1;
3828	mutex_unlock(&clk_debug_lock);
3829
3830	return 0;
3831}
3832late_initcall(clk_debug_init);
3833#else
3834static inline void clk_debug_register(struct clk_core *core) { }
3835static inline void clk_debug_unregister(struct clk_core *core)
3836{
3837}
3838#endif
3839
3840static void clk_core_reparent_orphans_nolock(void)
3841{
3842	struct clk_core *orphan;
3843	struct hlist_node *tmp2;
3844
3845	/*
3846	 * walk the list of orphan clocks and reparent any that newly finds a
3847	 * parent.
3848	 */
3849	hlist_for_each_entry_safe(orphan, tmp2, &clk_orphan_list, child_node) {
3850		struct clk_core *parent = __clk_init_parent(orphan);
3851
3852		/*
3853		 * We need to use __clk_set_parent_before() and _after() to
3854		 * properly migrate any prepare/enable count of the orphan
3855		 * clock. This is important for CLK_IS_CRITICAL clocks, which
3856		 * are enabled during init but might not have a parent yet.
3857		 */
3858		if (parent) {
3859			/* update the clk tree topology */
3860			__clk_set_parent_before(orphan, parent);
3861			__clk_set_parent_after(orphan, parent, NULL);
3862			__clk_recalc_accuracies(orphan);
3863			__clk_recalc_rates(orphan, true, 0);
3864
3865			/*
3866			 * __clk_init_parent() will set the initial req_rate to
3867			 * 0 if the clock doesn't have clk_ops::recalc_rate and
3868			 * is an orphan when it's registered.
3869			 *
3870			 * 'req_rate' is used by clk_set_rate_range() and
3871			 * clk_put() to trigger a clk_set_rate() call whenever
3872			 * the boundaries are modified. Let's make sure
3873			 * 'req_rate' is set to something non-zero so that
3874			 * clk_set_rate_range() doesn't drop the frequency.
3875			 */
3876			orphan->req_rate = orphan->rate;
3877		}
3878	}
3879}
3880
3881/**
3882 * __clk_core_init - initialize the data structures in a struct clk_core
3883 * @core:	clk_core being initialized
3884 *
3885 * Initializes the lists in struct clk_core, queries the hardware for the
3886 * parent and rate and sets them both.
3887 */
3888static int __clk_core_init(struct clk_core *core)
3889{
3890	int ret;
3891	struct clk_core *parent;
3892	unsigned long rate;
3893	int phase;
3894
3895	clk_prepare_lock();
3896
3897	/*
3898	 * Set hw->core after grabbing the prepare_lock to synchronize with
3899	 * callers of clk_core_fill_parent_index() where we treat hw->core
3900	 * being NULL as the clk not being registered yet. This is crucial so
3901	 * that clks aren't parented until their parent is fully registered.
3902	 */
3903	core->hw->core = core;
3904
3905	ret = clk_pm_runtime_get(core);
3906	if (ret)
3907		goto unlock;
3908
3909	/* check to see if a clock with this name is already registered */
3910	if (clk_core_lookup(core->name)) {
3911		pr_debug("%s: clk %s already initialized\n",
3912				__func__, core->name);
3913		ret = -EEXIST;
3914		goto out;
3915	}
3916
3917	/* check that clk_ops are sane.  See Documentation/driver-api/clk.rst */
3918	if (core->ops->set_rate &&
3919	    !((core->ops->round_rate || core->ops->determine_rate) &&
3920	      core->ops->recalc_rate)) {
3921		pr_err("%s: %s must implement .round_rate or .determine_rate in addition to .recalc_rate\n",
3922		       __func__, core->name);
3923		ret = -EINVAL;
3924		goto out;
3925	}
3926
3927	if (core->ops->set_parent && !core->ops->get_parent) {
3928		pr_err("%s: %s must implement .get_parent & .set_parent\n",
3929		       __func__, core->name);
3930		ret = -EINVAL;
3931		goto out;
3932	}
3933
3934	if (core->ops->set_parent && !core->ops->determine_rate) {
3935		pr_err("%s: %s must implement .set_parent & .determine_rate\n",
3936			__func__, core->name);
3937		ret = -EINVAL;
3938		goto out;
3939	}
3940
3941	if (core->num_parents > 1 && !core->ops->get_parent) {
3942		pr_err("%s: %s must implement .get_parent as it has multi parents\n",
3943		       __func__, core->name);
3944		ret = -EINVAL;
3945		goto out;
3946	}
3947
3948	if (core->ops->set_rate_and_parent &&
3949			!(core->ops->set_parent && core->ops->set_rate)) {
3950		pr_err("%s: %s must implement .set_parent & .set_rate\n",
3951				__func__, core->name);
3952		ret = -EINVAL;
3953		goto out;
3954	}
3955
3956	/*
3957	 * optional platform-specific magic
3958	 *
3959	 * The .init callback is not used by any of the basic clock types, but
3960	 * exists for weird hardware that must perform initialization magic for
3961	 * CCF to get an accurate view of clock for any other callbacks. It may
3962	 * also be used needs to perform dynamic allocations. Such allocation
3963	 * must be freed in the terminate() callback.
3964	 * This callback shall not be used to initialize the parameters state,
3965	 * such as rate, parent, etc ...
3966	 *
3967	 * If it exist, this callback should called before any other callback of
3968	 * the clock
3969	 */
3970	if (core->ops->init) {
3971		ret = core->ops->init(core->hw);
3972		if (ret)
3973			goto out;
3974	}
3975
3976	parent = core->parent = __clk_init_parent(core);
3977
3978	/*
3979	 * Populate core->parent if parent has already been clk_core_init'd. If
3980	 * parent has not yet been clk_core_init'd then place clk in the orphan
3981	 * list.  If clk doesn't have any parents then place it in the root
3982	 * clk list.
3983	 *
3984	 * Every time a new clk is clk_init'd then we walk the list of orphan
3985	 * clocks and re-parent any that are children of the clock currently
3986	 * being clk_init'd.
3987	 */
3988	if (parent) {
3989		hlist_add_head(&core->child_node, &parent->children);
3990		core->orphan = parent->orphan;
3991	} else if (!core->num_parents) {
3992		hlist_add_head(&core->child_node, &clk_root_list);
3993		core->orphan = false;
3994	} else {
3995		hlist_add_head(&core->child_node, &clk_orphan_list);
3996		core->orphan = true;
3997	}
3998	hash_add(clk_hashtable, &core->hashtable_node,
3999		 full_name_hash(NULL, core->name, strlen(core->name)));
4000
4001	/*
4002	 * Set clk's accuracy.  The preferred method is to use
4003	 * .recalc_accuracy. For simple clocks and lazy developers the default
4004	 * fallback is to use the parent's accuracy.  If a clock doesn't have a
4005	 * parent (or is orphaned) then accuracy is set to zero (perfect
4006	 * clock).
4007	 */
4008	if (core->ops->recalc_accuracy)
4009		core->accuracy = core->ops->recalc_accuracy(core->hw,
4010					clk_core_get_accuracy_no_lock(parent));
4011	else if (parent)
4012		core->accuracy = parent->accuracy;
4013	else
4014		core->accuracy = 0;
4015
4016	/*
4017	 * Set clk's phase by clk_core_get_phase() caching the phase.
4018	 * Since a phase is by definition relative to its parent, just
4019	 * query the current clock phase, or just assume it's in phase.
4020	 */
4021	phase = clk_core_get_phase(core);
4022	if (phase < 0) {
4023		ret = phase;
4024		pr_warn("%s: Failed to get phase for clk '%s'\n", __func__,
4025			core->name);
4026		goto out;
4027	}
4028
4029	/*
4030	 * Set clk's duty cycle.
4031	 */
4032	clk_core_update_duty_cycle_nolock(core);
4033
4034	/*
4035	 * Set clk's rate.  The preferred method is to use .recalc_rate.  For
4036	 * simple clocks and lazy developers the default fallback is to use the
4037	 * parent's rate.  If a clock doesn't have a parent (or is orphaned)
4038	 * then rate is set to zero.
4039	 */
4040	if (core->ops->recalc_rate)
4041		rate = core->ops->recalc_rate(core->hw,
4042				clk_core_get_rate_nolock(parent));
4043	else if (parent)
4044		rate = parent->rate;
4045	else
4046		rate = 0;
4047	core->rate = core->req_rate = rate;
4048
4049	/*
4050	 * Enable CLK_IS_CRITICAL clocks so newly added critical clocks
4051	 * don't get accidentally disabled when walking the orphan tree and
4052	 * reparenting clocks
4053	 */
4054	if (core->flags & CLK_IS_CRITICAL) {
4055		ret = clk_core_prepare(core);
4056		if (ret) {
4057			pr_warn("%s: critical clk '%s' failed to prepare\n",
4058			       __func__, core->name);
4059			goto out;
4060		}
4061
4062		ret = clk_core_enable_lock(core);
4063		if (ret) {
4064			pr_warn("%s: critical clk '%s' failed to enable\n",
4065			       __func__, core->name);
4066			clk_core_unprepare(core);
4067			goto out;
4068		}
4069	}
4070
4071	clk_core_reparent_orphans_nolock();
4072out:
4073	clk_pm_runtime_put(core);
4074unlock:
4075	if (ret) {
4076		hash_del(&core->hashtable_node);
4077		hlist_del_init(&core->child_node);
4078		core->hw->core = NULL;
4079	}
4080
4081	clk_prepare_unlock();
4082
4083	if (!ret)
4084		clk_debug_register(core);
4085
4086	return ret;
4087}
4088
4089/**
4090 * clk_core_link_consumer - Add a clk consumer to the list of consumers in a clk_core
4091 * @core: clk to add consumer to
4092 * @clk: consumer to link to a clk
4093 */
4094static void clk_core_link_consumer(struct clk_core *core, struct clk *clk)
4095{
4096	clk_prepare_lock();
4097	hlist_add_head(&clk->clks_node, &core->clks);
4098	clk_prepare_unlock();
4099}
4100
4101/**
4102 * clk_core_unlink_consumer - Remove a clk consumer from the list of consumers in a clk_core
4103 * @clk: consumer to unlink
4104 */
4105static void clk_core_unlink_consumer(struct clk *clk)
4106{
4107	lockdep_assert_held(&prepare_lock);
4108	hlist_del(&clk->clks_node);
4109}
4110
4111/**
4112 * alloc_clk - Allocate a clk consumer, but leave it unlinked to the clk_core
4113 * @core: clk to allocate a consumer for
4114 * @dev_id: string describing device name
4115 * @con_id: connection ID string on device
4116 *
4117 * Returns: clk consumer left unlinked from the consumer list
4118 */
4119static struct clk *alloc_clk(struct clk_core *core, const char *dev_id,
4120			     const char *con_id)
4121{
4122	struct clk *clk;
4123
4124	clk = kzalloc(sizeof(*clk), GFP_KERNEL);
4125	if (!clk)
4126		return ERR_PTR(-ENOMEM);
4127
4128	clk->core = core;
4129	clk->dev_id = dev_id;
4130	clk->con_id = kstrdup_const(con_id, GFP_KERNEL);
4131	clk->max_rate = ULONG_MAX;
4132
4133	return clk;
4134}
4135
4136/**
4137 * free_clk - Free a clk consumer
4138 * @clk: clk consumer to free
4139 *
4140 * Note, this assumes the clk has been unlinked from the clk_core consumer
4141 * list.
4142 */
4143static void free_clk(struct clk *clk)
4144{
4145	kfree_const(clk->con_id);
4146	kfree(clk);
4147}
4148
4149/**
4150 * clk_hw_create_clk: Allocate and link a clk consumer to a clk_core given
4151 * a clk_hw
4152 * @dev: clk consumer device
4153 * @hw: clk_hw associated with the clk being consumed
4154 * @dev_id: string describing device name
4155 * @con_id: connection ID string on device
4156 *
4157 * This is the main function used to create a clk pointer for use by clk
4158 * consumers. It connects a consumer to the clk_core and clk_hw structures
4159 * used by the framework and clk provider respectively.
4160 */
4161struct clk *clk_hw_create_clk(struct device *dev, struct clk_hw *hw,
4162			      const char *dev_id, const char *con_id)
4163{
4164	struct clk *clk;
4165	struct clk_core *core;
4166
4167	/* This is to allow this function to be chained to others */
4168	if (IS_ERR_OR_NULL(hw))
4169		return ERR_CAST(hw);
4170
4171	core = hw->core;
4172	clk = alloc_clk(core, dev_id, con_id);
4173	if (IS_ERR(clk))
4174		return clk;
4175	clk->dev = dev;
4176
4177	if (!try_module_get(core->owner)) {
4178		free_clk(clk);
4179		return ERR_PTR(-ENOENT);
4180	}
4181
4182	kref_get(&core->ref);
4183	clk_core_link_consumer(core, clk);
4184
4185	return clk;
4186}
4187
4188/**
4189 * clk_hw_get_clk - get clk consumer given an clk_hw
4190 * @hw: clk_hw associated with the clk being consumed
4191 * @con_id: connection ID string on device
4192 *
4193 * Returns: new clk consumer
4194 * This is the function to be used by providers which need
4195 * to get a consumer clk and act on the clock element
4196 * Calls to this function must be balanced with calls clk_put()
4197 */
4198struct clk *clk_hw_get_clk(struct clk_hw *hw, const char *con_id)
4199{
4200	struct device *dev = hw->core->dev;
4201	const char *name = dev ? dev_name(dev) : NULL;
4202
4203	return clk_hw_create_clk(dev, hw, name, con_id);
4204}
4205EXPORT_SYMBOL(clk_hw_get_clk);
4206
4207static int clk_cpy_name(const char **dst_p, const char *src, bool must_exist)
4208{
4209	const char *dst;
4210
4211	if (!src) {
4212		if (must_exist)
4213			return -EINVAL;
4214		return 0;
4215	}
4216
4217	*dst_p = dst = kstrdup_const(src, GFP_KERNEL);
4218	if (!dst)
4219		return -ENOMEM;
4220
4221	return 0;
4222}
4223
4224static int clk_core_populate_parent_map(struct clk_core *core,
4225					const struct clk_init_data *init)
4226{
4227	u8 num_parents = init->num_parents;
4228	const char * const *parent_names = init->parent_names;
4229	const struct clk_hw **parent_hws = init->parent_hws;
4230	const struct clk_parent_data *parent_data = init->parent_data;
4231	int i, ret = 0;
4232	struct clk_parent_map *parents, *parent;
4233
4234	if (!num_parents)
4235		return 0;
4236
4237	/*
4238	 * Avoid unnecessary string look-ups of clk_core's possible parents by
4239	 * having a cache of names/clk_hw pointers to clk_core pointers.
4240	 */
4241	parents = kcalloc(num_parents, sizeof(*parents), GFP_KERNEL);
4242	core->parents = parents;
4243	if (!parents)
4244		return -ENOMEM;
4245
4246	/* Copy everything over because it might be __initdata */
4247	for (i = 0, parent = parents; i < num_parents; i++, parent++) {
4248		parent->index = -1;
4249		if (parent_names) {
4250			/* throw a WARN if any entries are NULL */
4251			WARN(!parent_names[i],
4252				"%s: invalid NULL in %s's .parent_names\n",
4253				__func__, core->name);
4254			ret = clk_cpy_name(&parent->name, parent_names[i],
4255					   true);
4256		} else if (parent_data) {
4257			parent->hw = parent_data[i].hw;
4258			parent->index = parent_data[i].index;
4259			ret = clk_cpy_name(&parent->fw_name,
4260					   parent_data[i].fw_name, false);
4261			if (!ret)
4262				ret = clk_cpy_name(&parent->name,
4263						   parent_data[i].name,
4264						   false);
4265		} else if (parent_hws) {
4266			parent->hw = parent_hws[i];
4267		} else {
4268			ret = -EINVAL;
4269			WARN(1, "Must specify parents if num_parents > 0\n");
4270		}
4271
4272		if (ret) {
4273			do {
4274				kfree_const(parents[i].name);
4275				kfree_const(parents[i].fw_name);
4276			} while (--i >= 0);
4277			kfree(parents);
4278
4279			return ret;
4280		}
4281	}
4282
4283	return 0;
4284}
4285
4286static void clk_core_free_parent_map(struct clk_core *core)
4287{
4288	int i = core->num_parents;
4289
4290	if (!core->num_parents)
4291		return;
4292
4293	while (--i >= 0) {
4294		kfree_const(core->parents[i].name);
4295		kfree_const(core->parents[i].fw_name);
4296	}
4297
4298	kfree(core->parents);
4299}
4300
4301/* Free memory allocated for a struct clk_core */
4302static void __clk_release(struct kref *ref)
4303{
4304	struct clk_core *core = container_of(ref, struct clk_core, ref);
4305
4306	if (core->rpm_enabled) {
4307		mutex_lock(&clk_rpm_list_lock);
4308		hlist_del(&core->rpm_node);
4309		mutex_unlock(&clk_rpm_list_lock);
4310	}
4311
4312	clk_core_free_parent_map(core);
4313	kfree_const(core->name);
4314	kfree(core);
4315}
4316
4317static struct clk *
4318__clk_register(struct device *dev, struct device_node *np, struct clk_hw *hw)
4319{
4320	int ret;
4321	struct clk_core *core;
4322	const struct clk_init_data *init = hw->init;
4323
4324	/*
4325	 * The init data is not supposed to be used outside of registration path.
4326	 * Set it to NULL so that provider drivers can't use it either and so that
4327	 * we catch use of hw->init early on in the core.
4328	 */
4329	hw->init = NULL;
4330
4331	core = kzalloc(sizeof(*core), GFP_KERNEL);
4332	if (!core) {
4333		ret = -ENOMEM;
4334		goto fail_out;
4335	}
4336
4337	kref_init(&core->ref);
4338
4339	core->name = kstrdup_const(init->name, GFP_KERNEL);
4340	if (!core->name) {
4341		ret = -ENOMEM;
4342		goto fail_name;
4343	}
4344
4345	if (WARN_ON(!init->ops)) {
4346		ret = -EINVAL;
4347		goto fail_ops;
4348	}
4349	core->ops = init->ops;
4350
4351	core->dev = dev;
4352	clk_pm_runtime_init(core);
4353	core->of_node = np;
4354	if (dev && dev->driver)
4355		core->owner = dev->driver->owner;
4356	core->hw = hw;
4357	core->flags = init->flags;
4358	core->num_parents = init->num_parents;
4359	core->min_rate = 0;
4360	core->max_rate = ULONG_MAX;
4361
4362	ret = clk_core_populate_parent_map(core, init);
4363	if (ret)
4364		goto fail_parents;
4365
4366	INIT_HLIST_HEAD(&core->clks);
4367
4368	/*
4369	 * Don't call clk_hw_create_clk() here because that would pin the
4370	 * provider module to itself and prevent it from ever being removed.
4371	 */
4372	hw->clk = alloc_clk(core, NULL, NULL);
4373	if (IS_ERR(hw->clk)) {
4374		ret = PTR_ERR(hw->clk);
4375		goto fail_create_clk;
4376	}
4377
4378	clk_core_link_consumer(core, hw->clk);
4379
4380	ret = __clk_core_init(core);
4381	if (!ret)
4382		return hw->clk;
4383
4384	clk_prepare_lock();
4385	clk_core_unlink_consumer(hw->clk);
4386	clk_prepare_unlock();
4387
4388	free_clk(hw->clk);
4389	hw->clk = NULL;
4390
4391fail_create_clk:
4392fail_parents:
4393fail_ops:
4394fail_name:
4395	kref_put(&core->ref, __clk_release);
4396fail_out:
4397	if (dev) {
4398		dev_err_probe(dev, ret, "failed to register clk '%s' (%pS)\n",
4399			      init->name, hw);
4400	} else {
4401		pr_err("%pOF: error %pe: failed to register clk '%s' (%pS)\n",
4402		       np, ERR_PTR(ret), init->name, hw);
4403	}
4404	return ERR_PTR(ret);
4405}
4406
4407/**
4408 * dev_or_parent_of_node() - Get device node of @dev or @dev's parent
4409 * @dev: Device to get device node of
4410 *
4411 * Return: device node pointer of @dev, or the device node pointer of
4412 * @dev->parent if dev doesn't have a device node, or NULL if neither
4413 * @dev or @dev->parent have a device node.
4414 */
4415static struct device_node *dev_or_parent_of_node(struct device *dev)
4416{
4417	struct device_node *np;
4418
4419	if (!dev)
4420		return NULL;
4421
4422	np = dev_of_node(dev);
4423	if (!np)
4424		np = dev_of_node(dev->parent);
4425
4426	return np;
4427}
4428
4429/**
4430 * clk_register - allocate a new clock, register it and return an opaque cookie
4431 * @dev: device that is registering this clock
4432 * @hw: link to hardware-specific clock data
4433 *
4434 * clk_register is the *deprecated* interface for populating the clock tree with
4435 * new clock nodes. Use clk_hw_register() instead.
4436 *
4437 * Returns: a pointer to the newly allocated struct clk which
4438 * cannot be dereferenced by driver code but may be used in conjunction with the
4439 * rest of the clock API.  In the event of an error clk_register will return an
4440 * error code; drivers must test for an error code after calling clk_register.
4441 */
4442struct clk *clk_register(struct device *dev, struct clk_hw *hw)
4443{
4444	return __clk_register(dev, dev_or_parent_of_node(dev), hw);
4445}
4446EXPORT_SYMBOL_GPL(clk_register);
4447
4448/**
4449 * clk_hw_register - register a clk_hw and return an error code
4450 * @dev: device that is registering this clock
4451 * @hw: link to hardware-specific clock data
4452 *
4453 * clk_hw_register is the primary interface for populating the clock tree with
4454 * new clock nodes. It returns an integer equal to zero indicating success or
4455 * less than zero indicating failure. Drivers must test for an error code after
4456 * calling clk_hw_register().
4457 */
4458int clk_hw_register(struct device *dev, struct clk_hw *hw)
4459{
4460	return PTR_ERR_OR_ZERO(__clk_register(dev, dev_or_parent_of_node(dev),
4461			       hw));
4462}
4463EXPORT_SYMBOL_GPL(clk_hw_register);
4464
4465/*
4466 * of_clk_hw_register - register a clk_hw and return an error code
4467 * @node: device_node of device that is registering this clock
4468 * @hw: link to hardware-specific clock data
4469 *
4470 * of_clk_hw_register() is the primary interface for populating the clock tree
4471 * with new clock nodes when a struct device is not available, but a struct
4472 * device_node is. It returns an integer equal to zero indicating success or
4473 * less than zero indicating failure. Drivers must test for an error code after
4474 * calling of_clk_hw_register().
4475 */
4476int of_clk_hw_register(struct device_node *node, struct clk_hw *hw)
4477{
4478	return PTR_ERR_OR_ZERO(__clk_register(NULL, node, hw));
4479}
4480EXPORT_SYMBOL_GPL(of_clk_hw_register);
4481
4482/*
4483 * Empty clk_ops for unregistered clocks. These are used temporarily
4484 * after clk_unregister() was called on a clock and until last clock
4485 * consumer calls clk_put() and the struct clk object is freed.
4486 */
4487static int clk_nodrv_prepare_enable(struct clk_hw *hw)
4488{
4489	return -ENXIO;
4490}
4491
4492static void clk_nodrv_disable_unprepare(struct clk_hw *hw)
4493{
4494	WARN_ON_ONCE(1);
4495}
4496
4497static int clk_nodrv_set_rate(struct clk_hw *hw, unsigned long rate,
4498					unsigned long parent_rate)
4499{
4500	return -ENXIO;
4501}
4502
4503static int clk_nodrv_set_parent(struct clk_hw *hw, u8 index)
4504{
4505	return -ENXIO;
4506}
4507
4508static int clk_nodrv_determine_rate(struct clk_hw *hw,
4509				    struct clk_rate_request *req)
4510{
4511	return -ENXIO;
4512}
4513
4514static const struct clk_ops clk_nodrv_ops = {
4515	.enable		= clk_nodrv_prepare_enable,
4516	.disable	= clk_nodrv_disable_unprepare,
4517	.prepare	= clk_nodrv_prepare_enable,
4518	.unprepare	= clk_nodrv_disable_unprepare,
4519	.determine_rate	= clk_nodrv_determine_rate,
4520	.set_rate	= clk_nodrv_set_rate,
4521	.set_parent	= clk_nodrv_set_parent,
4522};
4523
4524static void clk_core_evict_parent_cache_subtree(struct clk_core *root,
4525						const struct clk_core *target)
4526{
4527	int i;
4528	struct clk_core *child;
4529
4530	for (i = 0; i < root->num_parents; i++)
4531		if (root->parents[i].core == target)
4532			root->parents[i].core = NULL;
4533
4534	hlist_for_each_entry(child, &root->children, child_node)
4535		clk_core_evict_parent_cache_subtree(child, target);
4536}
4537
4538/* Remove this clk from all parent caches */
4539static void clk_core_evict_parent_cache(struct clk_core *core)
4540{
4541	const struct hlist_head **lists;
4542	struct clk_core *root;
4543
4544	lockdep_assert_held(&prepare_lock);
4545
4546	for (lists = all_lists; *lists; lists++)
4547		hlist_for_each_entry(root, *lists, child_node)
4548			clk_core_evict_parent_cache_subtree(root, core);
4549
4550}
4551
4552/**
4553 * clk_unregister - unregister a currently registered clock
4554 * @clk: clock to unregister
4555 */
4556void clk_unregister(struct clk *clk)
4557{
4558	unsigned long flags;
4559	const struct clk_ops *ops;
4560
4561	if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4562		return;
4563
4564	clk_debug_unregister(clk->core);
4565
4566	clk_prepare_lock();
4567
4568	ops = clk->core->ops;
4569	if (ops == &clk_nodrv_ops) {
4570		pr_err("%s: unregistered clock: %s\n", __func__,
4571		       clk->core->name);
4572		clk_prepare_unlock();
4573		return;
4574	}
4575	/*
4576	 * Assign empty clock ops for consumers that might still hold
4577	 * a reference to this clock.
4578	 */
4579	flags = clk_enable_lock();
4580	clk->core->ops = &clk_nodrv_ops;
4581	clk_enable_unlock(flags);
4582
4583	if (ops->terminate)
4584		ops->terminate(clk->core->hw);
4585
4586	if (!hlist_empty(&clk->core->children)) {
4587		struct clk_core *child;
4588		struct hlist_node *t;
4589
4590		/* Reparent all children to the orphan list. */
4591		hlist_for_each_entry_safe(child, t, &clk->core->children,
4592					  child_node)
4593			clk_core_set_parent_nolock(child, NULL);
4594	}
4595
4596	clk_core_evict_parent_cache(clk->core);
4597
4598	hash_del(&clk->core->hashtable_node);
4599	hlist_del_init(&clk->core->child_node);
4600
4601	if (clk->core->prepare_count)
4602		pr_warn("%s: unregistering prepared clock: %s\n",
4603					__func__, clk->core->name);
4604
4605	if (clk->core->protect_count)
4606		pr_warn("%s: unregistering protected clock: %s\n",
4607					__func__, clk->core->name);
4608	clk_prepare_unlock();
4609
4610	kref_put(&clk->core->ref, __clk_release);
4611	free_clk(clk);
4612}
4613EXPORT_SYMBOL_GPL(clk_unregister);
4614
4615/**
4616 * clk_hw_unregister - unregister a currently registered clk_hw
4617 * @hw: hardware-specific clock data to unregister
4618 */
4619void clk_hw_unregister(struct clk_hw *hw)
4620{
4621	clk_unregister(hw->clk);
4622}
4623EXPORT_SYMBOL_GPL(clk_hw_unregister);
4624
4625static void devm_clk_unregister_cb(struct device *dev, void *res)
4626{
4627	clk_unregister(*(struct clk **)res);
4628}
4629
4630static void devm_clk_hw_unregister_cb(struct device *dev, void *res)
4631{
4632	clk_hw_unregister(*(struct clk_hw **)res);
4633}
4634
4635/**
4636 * devm_clk_register - resource managed clk_register()
4637 * @dev: device that is registering this clock
4638 * @hw: link to hardware-specific clock data
4639 *
4640 * Managed clk_register(). This function is *deprecated*, use devm_clk_hw_register() instead.
4641 *
4642 * Clocks returned from this function are automatically clk_unregister()ed on
4643 * driver detach. See clk_register() for more information.
4644 */
4645struct clk *devm_clk_register(struct device *dev, struct clk_hw *hw)
4646{
4647	struct clk *clk;
4648	struct clk **clkp;
4649
4650	clkp = devres_alloc(devm_clk_unregister_cb, sizeof(*clkp), GFP_KERNEL);
4651	if (!clkp)
4652		return ERR_PTR(-ENOMEM);
4653
4654	clk = clk_register(dev, hw);
4655	if (!IS_ERR(clk)) {
4656		*clkp = clk;
4657		devres_add(dev, clkp);
4658	} else {
4659		devres_free(clkp);
4660	}
4661
4662	return clk;
4663}
4664EXPORT_SYMBOL_GPL(devm_clk_register);
4665
4666/**
4667 * devm_clk_hw_register - resource managed clk_hw_register()
4668 * @dev: device that is registering this clock
4669 * @hw: link to hardware-specific clock data
4670 *
4671 * Managed clk_hw_register(). Clocks registered by this function are
4672 * automatically clk_hw_unregister()ed on driver detach. See clk_hw_register()
4673 * for more information.
4674 */
4675int devm_clk_hw_register(struct device *dev, struct clk_hw *hw)
4676{
4677	struct clk_hw **hwp;
4678	int ret;
4679
4680	hwp = devres_alloc(devm_clk_hw_unregister_cb, sizeof(*hwp), GFP_KERNEL);
4681	if (!hwp)
4682		return -ENOMEM;
4683
4684	ret = clk_hw_register(dev, hw);
4685	if (!ret) {
4686		*hwp = hw;
4687		devres_add(dev, hwp);
4688	} else {
4689		devres_free(hwp);
4690	}
4691
4692	return ret;
4693}
4694EXPORT_SYMBOL_GPL(devm_clk_hw_register);
4695
4696static void devm_clk_release(struct device *dev, void *res)
4697{
4698	clk_put(*(struct clk **)res);
4699}
4700
4701/**
4702 * devm_clk_hw_get_clk - resource managed clk_hw_get_clk()
4703 * @dev: device that is registering this clock
4704 * @hw: clk_hw associated with the clk being consumed
4705 * @con_id: connection ID string on device
4706 *
4707 * Managed clk_hw_get_clk(). Clocks got with this function are
4708 * automatically clk_put() on driver detach. See clk_put()
4709 * for more information.
4710 */
4711struct clk *devm_clk_hw_get_clk(struct device *dev, struct clk_hw *hw,
4712				const char *con_id)
4713{
4714	struct clk *clk;
4715	struct clk **clkp;
4716
4717	/* This should not happen because it would mean we have drivers
4718	 * passing around clk_hw pointers instead of having the caller use
4719	 * proper clk_get() style APIs
4720	 */
4721	WARN_ON_ONCE(dev != hw->core->dev);
4722
4723	clkp = devres_alloc(devm_clk_release, sizeof(*clkp), GFP_KERNEL);
4724	if (!clkp)
4725		return ERR_PTR(-ENOMEM);
4726
4727	clk = clk_hw_get_clk(hw, con_id);
4728	if (!IS_ERR(clk)) {
4729		*clkp = clk;
4730		devres_add(dev, clkp);
4731	} else {
4732		devres_free(clkp);
4733	}
4734
4735	return clk;
4736}
4737EXPORT_SYMBOL_GPL(devm_clk_hw_get_clk);
4738
4739/*
4740 * clkdev helpers
4741 */
4742
4743void __clk_put(struct clk *clk)
4744{
4745	struct module *owner;
4746
4747	if (!clk || WARN_ON_ONCE(IS_ERR(clk)))
4748		return;
4749
4750	clk_prepare_lock();
4751
4752	/*
4753	 * Before calling clk_put, all calls to clk_rate_exclusive_get() from a
4754	 * given user should be balanced with calls to clk_rate_exclusive_put()
4755	 * and by that same consumer
4756	 */
4757	if (WARN_ON(clk->exclusive_count)) {
4758		/* We voiced our concern, let's sanitize the situation */
4759		clk->core->protect_count -= (clk->exclusive_count - 1);
4760		clk_core_rate_unprotect(clk->core);
4761		clk->exclusive_count = 0;
4762	}
4763
4764	clk_core_unlink_consumer(clk);
4765
4766	/* If we had any boundaries on that clock, let's drop them. */
4767	if (clk->min_rate > 0 || clk->max_rate < ULONG_MAX)
4768		clk_set_rate_range_nolock(clk, 0, ULONG_MAX);
4769
4770	clk_prepare_unlock();
4771
4772	owner = clk->core->owner;
4773	kref_put(&clk->core->ref, __clk_release);
4774	module_put(owner);
4775	free_clk(clk);
4776}
4777
4778/***        clk rate change notifiers        ***/
4779
4780/**
4781 * clk_notifier_register - add a clk rate change notifier
4782 * @clk: struct clk * to watch
4783 * @nb: struct notifier_block * with callback info
4784 *
4785 * Request notification when clk's rate changes.  This uses an SRCU
4786 * notifier because we want it to block and notifier unregistrations are
4787 * uncommon.  The callbacks associated with the notifier must not
4788 * re-enter into the clk framework by calling any top-level clk APIs;
4789 * this will cause a nested prepare_lock mutex.
4790 *
4791 * In all notification cases (pre, post and abort rate change) the original
4792 * clock rate is passed to the callback via struct clk_notifier_data.old_rate
4793 * and the new frequency is passed via struct clk_notifier_data.new_rate.
4794 *
4795 * clk_notifier_register() must be called from non-atomic context.
4796 * Returns -EINVAL if called with null arguments, -ENOMEM upon
4797 * allocation failure; otherwise, passes along the return value of
4798 * srcu_notifier_chain_register().
4799 */
4800int clk_notifier_register(struct clk *clk, struct notifier_block *nb)
4801{
4802	struct clk_notifier *cn;
4803	int ret = -ENOMEM;
4804
4805	if (!clk || !nb)
4806		return -EINVAL;
4807
4808	clk_prepare_lock();
4809
4810	/* search the list of notifiers for this clk */
4811	list_for_each_entry(cn, &clk_notifier_list, node)
4812		if (cn->clk == clk)
4813			goto found;
4814
4815	/* if clk wasn't in the notifier list, allocate new clk_notifier */
4816	cn = kzalloc(sizeof(*cn), GFP_KERNEL);
4817	if (!cn)
4818		goto out;
4819
4820	cn->clk = clk;
4821	srcu_init_notifier_head(&cn->notifier_head);
4822
4823	list_add(&cn->node, &clk_notifier_list);
4824
4825found:
4826	ret = srcu_notifier_chain_register(&cn->notifier_head, nb);
4827
4828	clk->core->notifier_count++;
4829
4830out:
4831	clk_prepare_unlock();
4832
4833	return ret;
4834}
4835EXPORT_SYMBOL_GPL(clk_notifier_register);
4836
4837/**
4838 * clk_notifier_unregister - remove a clk rate change notifier
4839 * @clk: struct clk *
4840 * @nb: struct notifier_block * with callback info
4841 *
4842 * Request no further notification for changes to 'clk' and frees memory
4843 * allocated in clk_notifier_register.
4844 *
4845 * Returns -EINVAL if called with null arguments; otherwise, passes
4846 * along the return value of srcu_notifier_chain_unregister().
4847 */
4848int clk_notifier_unregister(struct clk *clk, struct notifier_block *nb)
4849{
4850	struct clk_notifier *cn;
4851	int ret = -ENOENT;
4852
4853	if (!clk || !nb)
4854		return -EINVAL;
4855
4856	clk_prepare_lock();
4857
4858	list_for_each_entry(cn, &clk_notifier_list, node) {
4859		if (cn->clk == clk) {
4860			ret = srcu_notifier_chain_unregister(&cn->notifier_head, nb);
4861
4862			clk->core->notifier_count--;
4863
4864			/* XXX the notifier code should handle this better */
4865			if (!cn->notifier_head.head) {
4866				srcu_cleanup_notifier_head(&cn->notifier_head);
4867				list_del(&cn->node);
4868				kfree(cn);
4869			}
4870			break;
4871		}
4872	}
4873
4874	clk_prepare_unlock();
4875
4876	return ret;
4877}
4878EXPORT_SYMBOL_GPL(clk_notifier_unregister);
4879
4880struct clk_notifier_devres {
4881	struct clk *clk;
4882	struct notifier_block *nb;
4883};
4884
4885static void devm_clk_notifier_release(struct device *dev, void *res)
4886{
4887	struct clk_notifier_devres *devres = res;
4888
4889	clk_notifier_unregister(devres->clk, devres->nb);
4890}
4891
4892int devm_clk_notifier_register(struct device *dev, struct clk *clk,
4893			       struct notifier_block *nb)
4894{
4895	struct clk_notifier_devres *devres;
4896	int ret;
4897
4898	devres = devres_alloc(devm_clk_notifier_release,
4899			      sizeof(*devres), GFP_KERNEL);
4900
4901	if (!devres)
4902		return -ENOMEM;
4903
4904	ret = clk_notifier_register(clk, nb);
4905	if (!ret) {
4906		devres->clk = clk;
4907		devres->nb = nb;
4908		devres_add(dev, devres);
4909	} else {
4910		devres_free(devres);
4911	}
4912
4913	return ret;
4914}
4915EXPORT_SYMBOL_GPL(devm_clk_notifier_register);
4916
4917#ifdef CONFIG_OF
4918static void clk_core_reparent_orphans(void)
4919{
4920	clk_prepare_lock();
4921	clk_core_reparent_orphans_nolock();
4922	clk_prepare_unlock();
4923}
4924
4925/**
4926 * struct of_clk_provider - Clock provider registration structure
4927 * @link: Entry in global list of clock providers
4928 * @node: Pointer to device tree node of clock provider
4929 * @get: Get clock callback.  Returns NULL or a struct clk for the
4930 *       given clock specifier
4931 * @get_hw: Get clk_hw callback.  Returns NULL, ERR_PTR or a
4932 *       struct clk_hw for the given clock specifier
4933 * @data: context pointer to be passed into @get callback
4934 */
4935struct of_clk_provider {
4936	struct list_head link;
4937
4938	struct device_node *node;
4939	struct clk *(*get)(struct of_phandle_args *clkspec, void *data);
4940	struct clk_hw *(*get_hw)(struct of_phandle_args *clkspec, void *data);
4941	void *data;
4942};
4943
4944extern struct of_device_id __clk_of_table;
4945static const struct of_device_id __clk_of_table_sentinel
4946	__used __section("__clk_of_table_end");
4947
4948static LIST_HEAD(of_clk_providers);
4949static DEFINE_MUTEX(of_clk_mutex);
4950
4951struct clk *of_clk_src_simple_get(struct of_phandle_args *clkspec,
4952				     void *data)
4953{
4954	return data;
4955}
4956EXPORT_SYMBOL_GPL(of_clk_src_simple_get);
4957
4958struct clk_hw *of_clk_hw_simple_get(struct of_phandle_args *clkspec, void *data)
4959{
4960	return data;
4961}
4962EXPORT_SYMBOL_GPL(of_clk_hw_simple_get);
4963
4964struct clk *of_clk_src_onecell_get(struct of_phandle_args *clkspec, void *data)
4965{
4966	struct clk_onecell_data *clk_data = data;
4967	unsigned int idx = clkspec->args[0];
4968
4969	if (idx >= clk_data->clk_num) {
4970		pr_err("%s: invalid clock index %u\n", __func__, idx);
4971		return ERR_PTR(-EINVAL);
4972	}
4973
4974	return clk_data->clks[idx];
4975}
4976EXPORT_SYMBOL_GPL(of_clk_src_onecell_get);
4977
4978struct clk_hw *
4979of_clk_hw_onecell_get(struct of_phandle_args *clkspec, void *data)
4980{
4981	struct clk_hw_onecell_data *hw_data = data;
4982	unsigned int idx = clkspec->args[0];
4983
4984	if (idx >= hw_data->num) {
4985		pr_err("%s: invalid index %u\n", __func__, idx);
4986		return ERR_PTR(-EINVAL);
4987	}
4988
4989	return hw_data->hws[idx];
4990}
4991EXPORT_SYMBOL_GPL(of_clk_hw_onecell_get);
4992
4993/**
4994 * of_clk_add_provider() - Register a clock provider for a node
4995 * @np: Device node pointer associated with clock provider
4996 * @clk_src_get: callback for decoding clock
4997 * @data: context pointer for @clk_src_get callback.
4998 *
4999 * This function is *deprecated*. Use of_clk_add_hw_provider() instead.
5000 */
5001int of_clk_add_provider(struct device_node *np,
5002			struct clk *(*clk_src_get)(struct of_phandle_args *clkspec,
5003						   void *data),
5004			void *data)
5005{
5006	struct of_clk_provider *cp;
5007	int ret;
5008
5009	if (!np)
5010		return 0;
5011
5012	cp = kzalloc(sizeof(*cp), GFP_KERNEL);
5013	if (!cp)
5014		return -ENOMEM;
5015
5016	cp->node = of_node_get(np);
5017	cp->data = data;
5018	cp->get = clk_src_get;
5019
5020	mutex_lock(&of_clk_mutex);
5021	list_add(&cp->link, &of_clk_providers);
5022	mutex_unlock(&of_clk_mutex);
5023	pr_debug("Added clock from %pOF\n", np);
5024
5025	clk_core_reparent_orphans();
5026
5027	ret = of_clk_set_defaults(np, true);
5028	if (ret < 0)
5029		of_clk_del_provider(np);
5030
5031	fwnode_dev_initialized(&np->fwnode, true);
5032
5033	return ret;
5034}
5035EXPORT_SYMBOL_GPL(of_clk_add_provider);
5036
5037/**
5038 * of_clk_add_hw_provider() - Register a clock provider for a node
5039 * @np: Device node pointer associated with clock provider
5040 * @get: callback for decoding clk_hw
5041 * @data: context pointer for @get callback.
5042 */
5043int of_clk_add_hw_provider(struct device_node *np,
5044			   struct clk_hw *(*get)(struct of_phandle_args *clkspec,
5045						 void *data),
5046			   void *data)
5047{
5048	struct of_clk_provider *cp;
5049	int ret;
5050
5051	if (!np)
5052		return 0;
5053
5054	cp = kzalloc(sizeof(*cp), GFP_KERNEL);
5055	if (!cp)
5056		return -ENOMEM;
5057
5058	cp->node = of_node_get(np);
5059	cp->data = data;
5060	cp->get_hw = get;
5061
5062	mutex_lock(&of_clk_mutex);
5063	list_add(&cp->link, &of_clk_providers);
5064	mutex_unlock(&of_clk_mutex);
5065	pr_debug("Added clk_hw provider from %pOF\n", np);
5066
5067	clk_core_reparent_orphans();
5068
5069	ret = of_clk_set_defaults(np, true);
5070	if (ret < 0)
5071		of_clk_del_provider(np);
5072
5073	fwnode_dev_initialized(&np->fwnode, true);
5074
5075	return ret;
5076}
5077EXPORT_SYMBOL_GPL(of_clk_add_hw_provider);
5078
5079static void devm_of_clk_release_provider(struct device *dev, void *res)
5080{
5081	of_clk_del_provider(*(struct device_node **)res);
5082}
5083
5084/*
5085 * We allow a child device to use its parent device as the clock provider node
5086 * for cases like MFD sub-devices where the child device driver wants to use
5087 * devm_*() APIs but not list the device in DT as a sub-node.
5088 */
5089static struct device_node *get_clk_provider_node(struct device *dev)
5090{
5091	struct device_node *np, *parent_np;
5092
5093	np = dev->of_node;
5094	parent_np = dev->parent ? dev->parent->of_node : NULL;
5095
5096	if (!of_property_present(np, "#clock-cells"))
5097		if (of_property_present(parent_np, "#clock-cells"))
5098			np = parent_np;
5099
5100	return np;
5101}
5102
5103/**
5104 * devm_of_clk_add_hw_provider() - Managed clk provider node registration
5105 * @dev: Device acting as the clock provider (used for DT node and lifetime)
5106 * @get: callback for decoding clk_hw
5107 * @data: context pointer for @get callback
5108 *
5109 * Registers clock provider for given device's node. If the device has no DT
5110 * node or if the device node lacks of clock provider information (#clock-cells)
5111 * then the parent device's node is scanned for this information. If parent node
5112 * has the #clock-cells then it is used in registration. Provider is
5113 * automatically released at device exit.
5114 *
5115 * Return: 0 on success or an errno on failure.
5116 */
5117int devm_of_clk_add_hw_provider(struct device *dev,
5118			struct clk_hw *(*get)(struct of_phandle_args *clkspec,
5119					      void *data),
5120			void *data)
5121{
5122	struct device_node **ptr, *np;
5123	int ret;
5124
5125	ptr = devres_alloc(devm_of_clk_release_provider, sizeof(*ptr),
5126			   GFP_KERNEL);
5127	if (!ptr)
5128		return -ENOMEM;
5129
5130	np = get_clk_provider_node(dev);
5131	ret = of_clk_add_hw_provider(np, get, data);
5132	if (!ret) {
5133		*ptr = np;
5134		devres_add(dev, ptr);
5135	} else {
5136		devres_free(ptr);
5137	}
5138
5139	return ret;
5140}
5141EXPORT_SYMBOL_GPL(devm_of_clk_add_hw_provider);
5142
5143/**
5144 * of_clk_del_provider() - Remove a previously registered clock provider
5145 * @np: Device node pointer associated with clock provider
5146 */
5147void of_clk_del_provider(struct device_node *np)
5148{
5149	struct of_clk_provider *cp;
5150
5151	if (!np)
5152		return;
5153
5154	mutex_lock(&of_clk_mutex);
5155	list_for_each_entry(cp, &of_clk_providers, link) {
5156		if (cp->node == np) {
5157			list_del(&cp->link);
5158			fwnode_dev_initialized(&np->fwnode, false);
5159			of_node_put(cp->node);
5160			kfree(cp);
5161			break;
5162		}
5163	}
5164	mutex_unlock(&of_clk_mutex);
5165}
5166EXPORT_SYMBOL_GPL(of_clk_del_provider);
5167
5168/**
5169 * of_parse_clkspec() - Parse a DT clock specifier for a given device node
5170 * @np: device node to parse clock specifier from
5171 * @index: index of phandle to parse clock out of. If index < 0, @name is used
5172 * @name: clock name to find and parse. If name is NULL, the index is used
5173 * @out_args: Result of parsing the clock specifier
5174 *
5175 * Parses a device node's "clocks" and "clock-names" properties to find the
5176 * phandle and cells for the index or name that is desired. The resulting clock
5177 * specifier is placed into @out_args, or an errno is returned when there's a
5178 * parsing error. The @index argument is ignored if @name is non-NULL.
5179 *
5180 * Example:
5181 *
5182 * phandle1: clock-controller@1 {
5183 *	#clock-cells = <2>;
5184 * }
5185 *
5186 * phandle2: clock-controller@2 {
5187 *	#clock-cells = <1>;
5188 * }
5189 *
5190 * clock-consumer@3 {
5191 *	clocks = <&phandle1 1 2 &phandle2 3>;
5192 *	clock-names = "name1", "name2";
5193 * }
5194 *
5195 * To get a device_node for `clock-controller@2' node you may call this
5196 * function a few different ways:
5197 *
5198 *   of_parse_clkspec(clock-consumer@3, -1, "name2", &args);
5199 *   of_parse_clkspec(clock-consumer@3, 1, NULL, &args);
5200 *   of_parse_clkspec(clock-consumer@3, 1, "name2", &args);
5201 *
5202 * Return: 0 upon successfully parsing the clock specifier. Otherwise, -ENOENT
5203 * if @name is NULL or -EINVAL if @name is non-NULL and it can't be found in
5204 * the "clock-names" property of @np.
5205 */
5206static int of_parse_clkspec(const struct device_node *np, int index,
5207			    const char *name, struct of_phandle_args *out_args)
5208{
5209	int ret = -ENOENT;
5210
5211	/* Walk up the tree of devices looking for a clock property that matches */
5212	while (np) {
5213		/*
5214		 * For named clocks, first look up the name in the
5215		 * "clock-names" property.  If it cannot be found, then index
5216		 * will be an error code and of_parse_phandle_with_args() will
5217		 * return -EINVAL.
5218		 */
5219		if (name)
5220			index = of_property_match_string(np, "clock-names", name);
5221		ret = of_parse_phandle_with_args(np, "clocks", "#clock-cells",
5222						 index, out_args);
5223		if (!ret)
5224			break;
5225		if (name && index >= 0)
5226			break;
5227
5228		/*
5229		 * No matching clock found on this node.  If the parent node
5230		 * has a "clock-ranges" property, then we can try one of its
5231		 * clocks.
5232		 */
5233		np = np->parent;
5234		if (np && !of_property_present(np, "clock-ranges"))
5235			break;
5236		index = 0;
5237	}
5238
5239	return ret;
5240}
5241
5242static struct clk_hw *
5243__of_clk_get_hw_from_provider(struct of_clk_provider *provider,
5244			      struct of_phandle_args *clkspec)
5245{
5246	struct clk *clk;
5247
5248	if (provider->get_hw)
5249		return provider->get_hw(clkspec, provider->data);
5250
5251	clk = provider->get(clkspec, provider->data);
5252	if (IS_ERR(clk))
5253		return ERR_CAST(clk);
5254	return __clk_get_hw(clk);
5255}
5256
5257static struct clk_hw *
5258of_clk_get_hw_from_clkspec(struct of_phandle_args *clkspec)
5259{
5260	struct of_clk_provider *provider;
5261	struct clk_hw *hw = ERR_PTR(-EPROBE_DEFER);
5262
5263	if (!clkspec)
5264		return ERR_PTR(-EINVAL);
5265
5266	/* Check if node in clkspec is in disabled/fail state */
5267	if (!of_device_is_available(clkspec->np))
5268		return ERR_PTR(-ENOENT);
5269
5270	mutex_lock(&of_clk_mutex);
5271	list_for_each_entry(provider, &of_clk_providers, link) {
5272		if (provider->node == clkspec->np) {
5273			hw = __of_clk_get_hw_from_provider(provider, clkspec);
5274			if (!IS_ERR(hw))
5275				break;
5276		}
5277	}
5278	mutex_unlock(&of_clk_mutex);
5279
5280	return hw;
5281}
5282
5283/**
5284 * of_clk_get_from_provider() - Lookup a clock from a clock provider
5285 * @clkspec: pointer to a clock specifier data structure
5286 *
5287 * This function looks up a struct clk from the registered list of clock
5288 * providers, an input is a clock specifier data structure as returned
5289 * from the of_parse_phandle_with_args() function call.
5290 */
5291struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec)
5292{
5293	struct clk_hw *hw = of_clk_get_hw_from_clkspec(clkspec);
5294
5295	return clk_hw_create_clk(NULL, hw, NULL, __func__);
5296}
5297EXPORT_SYMBOL_GPL(of_clk_get_from_provider);
5298
5299struct clk_hw *of_clk_get_hw(struct device_node *np, int index,
5300			     const char *con_id)
5301{
5302	int ret;
5303	struct clk_hw *hw;
5304	struct of_phandle_args clkspec;
5305
5306	ret = of_parse_clkspec(np, index, con_id, &clkspec);
5307	if (ret)
5308		return ERR_PTR(ret);
5309
5310	hw = of_clk_get_hw_from_clkspec(&clkspec);
5311	of_node_put(clkspec.np);
5312
5313	return hw;
5314}
5315
5316static struct clk *__of_clk_get(struct device_node *np,
5317				int index, const char *dev_id,
5318				const char *con_id)
5319{
5320	struct clk_hw *hw = of_clk_get_hw(np, index, con_id);
5321
5322	return clk_hw_create_clk(NULL, hw, dev_id, con_id);
5323}
5324
5325struct clk *of_clk_get(struct device_node *np, int index)
5326{
5327	return __of_clk_get(np, index, np->full_name, NULL);
5328}
5329EXPORT_SYMBOL(of_clk_get);
5330
5331/**
5332 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
5333 * @np: pointer to clock consumer node
5334 * @name: name of consumer's clock input, or NULL for the first clock reference
5335 *
5336 * This function parses the clocks and clock-names properties,
5337 * and uses them to look up the struct clk from the registered list of clock
5338 * providers.
5339 */
5340struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
5341{
5342	if (!np)
5343		return ERR_PTR(-ENOENT);
5344
5345	return __of_clk_get(np, 0, np->full_name, name);
5346}
5347EXPORT_SYMBOL(of_clk_get_by_name);
5348
5349/**
5350 * of_clk_get_parent_count() - Count the number of clocks a device node has
5351 * @np: device node to count
5352 *
5353 * Returns: The number of clocks that are possible parents of this node
5354 */
5355unsigned int of_clk_get_parent_count(const struct device_node *np)
5356{
5357	int count;
5358
5359	count = of_count_phandle_with_args(np, "clocks", "#clock-cells");
5360	if (count < 0)
5361		return 0;
5362
5363	return count;
5364}
5365EXPORT_SYMBOL_GPL(of_clk_get_parent_count);
5366
5367const char *of_clk_get_parent_name(const struct device_node *np, int index)
5368{
5369	struct of_phandle_args clkspec;
5370	const char *clk_name;
5371	bool found = false;
5372	u32 pv;
5373	int rc;
5374	int count;
5375	struct clk *clk;
5376
5377	rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
5378					&clkspec);
5379	if (rc)
5380		return NULL;
5381
5382	index = clkspec.args_count ? clkspec.args[0] : 0;
5383	count = 0;
5384
5385	/* if there is an indices property, use it to transfer the index
5386	 * specified into an array offset for the clock-output-names property.
5387	 */
5388	of_property_for_each_u32(clkspec.np, "clock-indices", pv) {
5389		if (index == pv) {
5390			index = count;
5391			found = true;
5392			break;
5393		}
5394		count++;
5395	}
5396	/* We went off the end of 'clock-indices' without finding it */
5397	if (of_property_present(clkspec.np, "clock-indices") && !found) {
5398		of_node_put(clkspec.np);
5399		return NULL;
5400	}
5401
5402	if (of_property_read_string_index(clkspec.np, "clock-output-names",
5403					  index,
5404					  &clk_name) < 0) {
5405		/*
5406		 * Best effort to get the name if the clock has been
5407		 * registered with the framework. If the clock isn't
5408		 * registered, we return the node name as the name of
5409		 * the clock as long as #clock-cells = 0.
5410		 */
5411		clk = of_clk_get_from_provider(&clkspec);
5412		if (IS_ERR(clk)) {
5413			if (clkspec.args_count == 0)
5414				clk_name = clkspec.np->name;
5415			else
5416				clk_name = NULL;
5417		} else {
5418			clk_name = __clk_get_name(clk);
5419			clk_put(clk);
5420		}
5421	}
5422
5423
5424	of_node_put(clkspec.np);
5425	return clk_name;
5426}
5427EXPORT_SYMBOL_GPL(of_clk_get_parent_name);
5428
5429/**
5430 * of_clk_parent_fill() - Fill @parents with names of @np's parents and return
5431 * number of parents
5432 * @np: Device node pointer associated with clock provider
5433 * @parents: pointer to char array that hold the parents' names
5434 * @size: size of the @parents array
5435 *
5436 * Return: number of parents for the clock node.
5437 */
5438int of_clk_parent_fill(struct device_node *np, const char **parents,
5439		       unsigned int size)
5440{
5441	unsigned int i = 0;
5442
5443	while (i < size && (parents[i] = of_clk_get_parent_name(np, i)) != NULL)
5444		i++;
5445
5446	return i;
5447}
5448EXPORT_SYMBOL_GPL(of_clk_parent_fill);
5449
5450struct clock_provider {
5451	void (*clk_init_cb)(struct device_node *);
5452	struct device_node *np;
5453	struct list_head node;
5454};
5455
5456/*
5457 * This function looks for a parent clock. If there is one, then it
5458 * checks that the provider for this parent clock was initialized, in
5459 * this case the parent clock will be ready.
5460 */
5461static int parent_ready(struct device_node *np)
5462{
5463	int i = 0;
5464
5465	while (true) {
5466		struct clk *clk = of_clk_get(np, i);
5467
5468		/* this parent is ready we can check the next one */
5469		if (!IS_ERR(clk)) {
5470			clk_put(clk);
5471			i++;
5472			continue;
5473		}
5474
5475		/* at least one parent is not ready, we exit now */
5476		if (PTR_ERR(clk) == -EPROBE_DEFER)
5477			return 0;
5478
5479		/*
5480		 * Here we make assumption that the device tree is
5481		 * written correctly. So an error means that there is
5482		 * no more parent. As we didn't exit yet, then the
5483		 * previous parent are ready. If there is no clock
5484		 * parent, no need to wait for them, then we can
5485		 * consider their absence as being ready
5486		 */
5487		return 1;
5488	}
5489}
5490
5491/**
5492 * of_clk_detect_critical() - set CLK_IS_CRITICAL flag from Device Tree
5493 * @np: Device node pointer associated with clock provider
5494 * @index: clock index
5495 * @flags: pointer to top-level framework flags
5496 *
5497 * Detects if the clock-critical property exists and, if so, sets the
5498 * corresponding CLK_IS_CRITICAL flag.
5499 *
5500 * Do not use this function. It exists only for legacy Device Tree
5501 * bindings, such as the one-clock-per-node style that are outdated.
5502 * Those bindings typically put all clock data into .dts and the Linux
5503 * driver has no clock data, thus making it impossible to set this flag
5504 * correctly from the driver. Only those drivers may call
5505 * of_clk_detect_critical from their setup functions.
5506 *
5507 * Return: error code or zero on success
5508 */
5509int of_clk_detect_critical(struct device_node *np, int index,
5510			   unsigned long *flags)
5511{
5512	uint32_t idx;
5513
5514	if (!np || !flags)
5515		return -EINVAL;
5516
5517	of_property_for_each_u32(np, "clock-critical", idx)
5518		if (index == idx)
5519			*flags |= CLK_IS_CRITICAL;
5520
5521	return 0;
5522}
5523
5524/**
5525 * of_clk_init() - Scan and init clock providers from the DT
5526 * @matches: array of compatible values and init functions for providers.
5527 *
5528 * This function scans the device tree for matching clock providers
5529 * and calls their initialization functions. It also does it by trying
5530 * to follow the dependencies.
5531 */
5532void __init of_clk_init(const struct of_device_id *matches)
5533{
5534	const struct of_device_id *match;
5535	struct device_node *np;
5536	struct clock_provider *clk_provider, *next;
5537	bool is_init_done;
5538	bool force = false;
5539	LIST_HEAD(clk_provider_list);
5540
5541	if (!matches)
5542		matches = &__clk_of_table;
5543
5544	/* First prepare the list of the clocks providers */
5545	for_each_matching_node_and_match(np, matches, &match) {
5546		struct clock_provider *parent;
5547
5548		if (!of_device_is_available(np))
5549			continue;
5550
5551		parent = kzalloc(sizeof(*parent), GFP_KERNEL);
5552		if (!parent) {
5553			list_for_each_entry_safe(clk_provider, next,
5554						 &clk_provider_list, node) {
5555				list_del(&clk_provider->node);
5556				of_node_put(clk_provider->np);
5557				kfree(clk_provider);
5558			}
5559			of_node_put(np);
5560			return;
5561		}
5562
5563		parent->clk_init_cb = match->data;
5564		parent->np = of_node_get(np);
5565		list_add_tail(&parent->node, &clk_provider_list);
5566	}
5567
5568	while (!list_empty(&clk_provider_list)) {
5569		is_init_done = false;
5570		list_for_each_entry_safe(clk_provider, next,
5571					&clk_provider_list, node) {
5572			if (force || parent_ready(clk_provider->np)) {
5573
5574				/* Don't populate platform devices */
5575				of_node_set_flag(clk_provider->np,
5576						 OF_POPULATED);
5577
5578				clk_provider->clk_init_cb(clk_provider->np);
5579				of_clk_set_defaults(clk_provider->np, true);
5580
5581				list_del(&clk_provider->node);
5582				of_node_put(clk_provider->np);
5583				kfree(clk_provider);
5584				is_init_done = true;
5585			}
5586		}
5587
5588		/*
5589		 * We didn't manage to initialize any of the
5590		 * remaining providers during the last loop, so now we
5591		 * initialize all the remaining ones unconditionally
5592		 * in case the clock parent was not mandatory
5593		 */
5594		if (!is_init_done)
5595			force = true;
5596	}
5597}
5598#endif