core.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Copyright (c) 2011-2017, The Linux Foundation
  4 */
  5
  6#include <linux/kernel.h>
  7#include <linux/errno.h>
  8#include <linux/slab.h>
  9#include <linux/init.h>
 10#include <linux/idr.h>
 11#include <linux/of.h>
 12#include <linux/of_device.h>
 13#include <linux/pm_runtime.h>
 14#include <linux/slimbus.h>
 15#include "slimbus.h"
 16
 17static DEFINE_IDA(ctrl_ida);
 18
 19static const struct slim_device_id *slim_match(const struct slim_device_id *id,
 20					       const struct slim_device *sbdev)
 21{
 22	while (id->manf_id != 0 || id->prod_code != 0) {
 23		if (id->manf_id == sbdev->e_addr.manf_id &&
 24		    id->prod_code == sbdev->e_addr.prod_code &&
 25		    id->dev_index == sbdev->e_addr.dev_index &&
 26		    id->instance == sbdev->e_addr.instance)
 27			return id;
 28		id++;
 29	}
 30	return NULL;
 31}
 32
 33static int slim_device_match(struct device *dev, const struct device_driver *drv)
 34{
 35	struct slim_device *sbdev = to_slim_device(dev);
 36	const struct slim_driver *sbdrv = to_slim_driver(drv);
 37
 38	/* Attempt an OF style match first */
 39	if (of_driver_match_device(dev, drv))
 40		return 1;
 41
 42	return !!slim_match(sbdrv->id_table, sbdev);
 43}
 44
 45static void slim_device_update_status(struct slim_device *sbdev,
 46				      enum slim_device_status status)
 47{
 48	struct slim_driver *sbdrv;
 49
 50	if (sbdev->status == status)
 51		return;
 52
 53	sbdev->status = status;
 54	if (!sbdev->dev.driver)
 55		return;
 56
 57	sbdrv = to_slim_driver(sbdev->dev.driver);
 58	if (sbdrv->device_status)
 59		sbdrv->device_status(sbdev, sbdev->status);
 60}
 61
 62static int slim_device_probe(struct device *dev)
 63{
 64	struct slim_device	*sbdev = to_slim_device(dev);
 65	struct slim_driver	*sbdrv = to_slim_driver(dev->driver);
 66	int ret;
 67
 68	ret = sbdrv->probe(sbdev);
 69	if (ret)
 70		return ret;
 71
 72	/* try getting the logical address after probe */
 73	ret = slim_get_logical_addr(sbdev);
 74	if (!ret) {
 75		slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP);
 76	} else {
 77		dev_err(&sbdev->dev, "Failed to get logical address\n");
 78		ret = -EPROBE_DEFER;
 79	}
 80
 81	return ret;
 82}
 83
 84static void slim_device_remove(struct device *dev)
 85{
 86	struct slim_device *sbdev = to_slim_device(dev);
 87	struct slim_driver *sbdrv;
 88
 89	if (dev->driver) {
 90		sbdrv = to_slim_driver(dev->driver);
 91		if (sbdrv->remove)
 92			sbdrv->remove(sbdev);
 93	}
 94}
 95
 96static int slim_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
 97{
 98	const struct slim_device *sbdev = to_slim_device(dev);
 99
100	return add_uevent_var(env, "MODALIAS=slim:%s", dev_name(&sbdev->dev));
101}
102
103const struct bus_type slimbus_bus = {
104	.name		= "slimbus",
105	.match		= slim_device_match,
106	.probe		= slim_device_probe,
107	.remove		= slim_device_remove,
108	.uevent		= slim_device_uevent,
109};
110EXPORT_SYMBOL_GPL(slimbus_bus);
111
112/*
113 * __slim_driver_register() - Client driver registration with SLIMbus
114 *
115 * @drv:Client driver to be associated with client-device.
116 * @owner: owning module/driver
117 *
118 * This API will register the client driver with the SLIMbus
119 * It is called from the driver's module-init function.
120 */
121int __slim_driver_register(struct slim_driver *drv, struct module *owner)
122{
123	/* ID table and probe are mandatory */
124	if (!(drv->driver.of_match_table || drv->id_table) || !drv->probe)
125		return -EINVAL;
126
127	drv->driver.bus = &slimbus_bus;
128	drv->driver.owner = owner;
129
130	return driver_register(&drv->driver);
131}
132EXPORT_SYMBOL_GPL(__slim_driver_register);
133
134/*
135 * slim_driver_unregister() - Undo effect of slim_driver_register
136 *
137 * @drv: Client driver to be unregistered
138 */
139void slim_driver_unregister(struct slim_driver *drv)
140{
141	driver_unregister(&drv->driver);
142}
143EXPORT_SYMBOL_GPL(slim_driver_unregister);
144
145static void slim_dev_release(struct device *dev)
146{
147	struct slim_device *sbdev = to_slim_device(dev);
148
149	of_node_put(sbdev->dev.of_node);
150	kfree(sbdev);
151}
152
153static int slim_add_device(struct slim_controller *ctrl,
154			   struct slim_device *sbdev,
155			   struct device_node *node)
156{
157	sbdev->dev.bus = &slimbus_bus;
158	sbdev->dev.parent = ctrl->dev;
159	sbdev->dev.release = slim_dev_release;
160	sbdev->dev.driver = NULL;
161	sbdev->ctrl = ctrl;
162	INIT_LIST_HEAD(&sbdev->stream_list);
163	spin_lock_init(&sbdev->stream_list_lock);
164	sbdev->dev.of_node = of_node_get(node);
165	sbdev->dev.fwnode = of_fwnode_handle(node);
166
167	dev_set_name(&sbdev->dev, "%x:%x:%x:%x",
168				  sbdev->e_addr.manf_id,
169				  sbdev->e_addr.prod_code,
170				  sbdev->e_addr.dev_index,
171				  sbdev->e_addr.instance);
172
173	return device_register(&sbdev->dev);
174}
175
176static struct slim_device *slim_alloc_device(struct slim_controller *ctrl,
177					     struct slim_eaddr *eaddr,
178					     struct device_node *node)
179{
180	struct slim_device *sbdev;
181	int ret;
182
183	sbdev = kzalloc(sizeof(*sbdev), GFP_KERNEL);
184	if (!sbdev)
185		return NULL;
186
187	sbdev->e_addr = *eaddr;
188	ret = slim_add_device(ctrl, sbdev, node);
189	if (ret) {
190		put_device(&sbdev->dev);
191		return NULL;
192	}
193
194	return sbdev;
195}
196
197static void of_register_slim_devices(struct slim_controller *ctrl)
198{
199	struct device *dev = ctrl->dev;
200	struct device_node *node;
201
202	if (!ctrl->dev->of_node)
203		return;
204
205	for_each_child_of_node(ctrl->dev->of_node, node) {
206		struct slim_device *sbdev;
207		struct slim_eaddr e_addr;
208		const char *compat = NULL;
209		int reg[2], ret;
210		int manf_id, prod_code;
211
212		compat = of_get_property(node, "compatible", NULL);
213		if (!compat)
214			continue;
215
216		ret = sscanf(compat, "slim%x,%x", &manf_id, &prod_code);
217		if (ret != 2) {
218			dev_err(dev, "Manf ID & Product code not found %s\n",
219				compat);
220			continue;
221		}
222
223		ret = of_property_read_u32_array(node, "reg", reg, 2);
224		if (ret) {
225			dev_err(dev, "Device and Instance id not found:%d\n",
226				ret);
227			continue;
228		}
229
230		e_addr.dev_index = reg[0];
231		e_addr.instance = reg[1];
232		e_addr.manf_id = manf_id;
233		e_addr.prod_code = prod_code;
234
235		sbdev = slim_alloc_device(ctrl, &e_addr, node);
236		if (!sbdev)
237			continue;
238	}
239}
240
241/*
242 * slim_register_controller() - Controller bring-up and registration.
243 *
244 * @ctrl: Controller to be registered.
245 *
246 * A controller is registered with the framework using this API.
247 * If devices on a controller were registered before controller,
248 * this will make sure that they get probed when controller is up
249 */
250int slim_register_controller(struct slim_controller *ctrl)
251{
252	int id;
253
254	id = ida_alloc(&ctrl_ida, GFP_KERNEL);
255	if (id < 0)
256		return id;
257
258	ctrl->id = id;
259
260	if (!ctrl->min_cg)
261		ctrl->min_cg = SLIM_MIN_CLK_GEAR;
262	if (!ctrl->max_cg)
263		ctrl->max_cg = SLIM_MAX_CLK_GEAR;
264
265	ida_init(&ctrl->laddr_ida);
266	idr_init(&ctrl->tid_idr);
267	mutex_init(&ctrl->lock);
268	mutex_init(&ctrl->sched.m_reconf);
269	init_completion(&ctrl->sched.pause_comp);
270	spin_lock_init(&ctrl->txn_lock);
271
272	dev_dbg(ctrl->dev, "Bus [%s] registered:dev:%p\n",
273		ctrl->name, ctrl->dev);
274
275	of_register_slim_devices(ctrl);
276
277	return 0;
278}
279EXPORT_SYMBOL_GPL(slim_register_controller);
280
281/* slim_remove_device: Remove the effect of slim_add_device() */
282static void slim_remove_device(struct slim_device *sbdev)
283{
284	device_unregister(&sbdev->dev);
285}
286
287static int slim_ctrl_remove_device(struct device *dev, void *null)
288{
289	slim_remove_device(to_slim_device(dev));
290	return 0;
291}
292
293/**
294 * slim_unregister_controller() - Controller tear-down.
295 *
296 * @ctrl: Controller to tear-down.
297 */
298int slim_unregister_controller(struct slim_controller *ctrl)
299{
300	/* Remove all clients */
301	device_for_each_child(ctrl->dev, NULL, slim_ctrl_remove_device);
302	ida_free(&ctrl_ida, ctrl->id);
303
304	return 0;
305}
306EXPORT_SYMBOL_GPL(slim_unregister_controller);
307
308/**
309 * slim_report_absent() - Controller calls this function when a device
310 *	reports absent, OR when the device cannot be communicated with
311 *
312 * @sbdev: Device that cannot be reached, or sent report absent
313 */
314void slim_report_absent(struct slim_device *sbdev)
315{
316	struct slim_controller *ctrl = sbdev->ctrl;
317
318	if (!ctrl)
319		return;
320
321	/* invalidate logical addresses */
322	mutex_lock(&ctrl->lock);
323	sbdev->is_laddr_valid = false;
324	mutex_unlock(&ctrl->lock);
325	if (!ctrl->get_laddr)
326		ida_free(&ctrl->laddr_ida, sbdev->laddr);
327	slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_DOWN);
328}
329EXPORT_SYMBOL_GPL(slim_report_absent);
330
331static bool slim_eaddr_equal(const struct slim_eaddr *a,
332			     const struct slim_eaddr *b)
333{
334	return (a->manf_id == b->manf_id &&
335		a->prod_code == b->prod_code &&
336		a->dev_index == b->dev_index &&
337		a->instance == b->instance);
338}
339
340static int slim_match_dev(struct device *dev, const void *data)
341{
342	const struct slim_eaddr *e_addr = data;
343	struct slim_device *sbdev = to_slim_device(dev);
344
345	return slim_eaddr_equal(&sbdev->e_addr, e_addr);
346}
347
348static struct slim_device *find_slim_device(struct slim_controller *ctrl,
349					    struct slim_eaddr *eaddr)
350{
351	struct slim_device *sbdev;
352	struct device *dev;
353
354	dev = device_find_child(ctrl->dev, eaddr, slim_match_dev);
355	if (dev) {
356		sbdev = to_slim_device(dev);
357		return sbdev;
358	}
359
360	return NULL;
361}
362
363/**
364 * slim_get_device() - get handle to a device.
365 *
366 * @ctrl: Controller on which this device will be added/queried
367 * @e_addr: Enumeration address of the device to be queried
368 *
369 * Takes a reference to the embedded struct device which needs to be dropped
370 * after use.
371 *
372 * Return: pointer to a device if it has already reported. Creates a new
373 * device and returns pointer to it if the device has not yet enumerated.
374 */
375struct slim_device *slim_get_device(struct slim_controller *ctrl,
376				    struct slim_eaddr *e_addr)
377{
378	struct slim_device *sbdev;
379
380	sbdev = find_slim_device(ctrl, e_addr);
381	if (!sbdev) {
382		sbdev = slim_alloc_device(ctrl, e_addr, NULL);
383		if (!sbdev)
384			return ERR_PTR(-ENOMEM);
385
386		get_device(&sbdev->dev);
387	}
388
389	return sbdev;
390}
391EXPORT_SYMBOL_GPL(slim_get_device);
392
393/**
394 * of_slim_get_device() - get handle to a device using dt node.
395 *
396 * @ctrl: Controller on which this device will be queried
397 * @np: node pointer to device
398 *
399 * Takes a reference to the embedded struct device which needs to be dropped
400 * after use.
401 *
402 * Return: pointer to a device if it has been registered, otherwise NULL.
403 */
404struct slim_device *of_slim_get_device(struct slim_controller *ctrl,
405				       struct device_node *np)
406{
407	struct slim_device *sbdev;
408	struct device *dev;
409
410	dev = device_find_child(ctrl->dev, np, device_match_of_node);
411	if (dev) {
412		sbdev = to_slim_device(dev);
413		return sbdev;
414	}
415
416	return NULL;
417}
418EXPORT_SYMBOL_GPL(of_slim_get_device);
419
420static int slim_device_alloc_laddr(struct slim_device *sbdev,
421				   bool report_present)
422{
423	struct slim_controller *ctrl = sbdev->ctrl;
424	u8 laddr;
425	int ret;
426
427	mutex_lock(&ctrl->lock);
428	if (ctrl->get_laddr) {
429		ret = ctrl->get_laddr(ctrl, &sbdev->e_addr, &laddr);
430		if (ret < 0)
431			goto err;
432	} else if (report_present) {
433		ret = ida_alloc_max(&ctrl->laddr_ida,
434				    SLIM_LA_MANAGER - 1, GFP_KERNEL);
435		if (ret < 0)
436			goto err;
437
438		laddr = ret;
439	} else {
440		ret = -EINVAL;
441		goto err;
442	}
443
444	if (ctrl->set_laddr) {
445		ret = ctrl->set_laddr(ctrl, &sbdev->e_addr, laddr);
446		if (ret) {
447			ret = -EINVAL;
448			goto err;
449		}
450	}
451
452	sbdev->laddr = laddr;
453	sbdev->is_laddr_valid = true;
454	mutex_unlock(&ctrl->lock);
455
456	slim_device_update_status(sbdev, SLIM_DEVICE_STATUS_UP);
457
458	dev_dbg(ctrl->dev, "setting slimbus l-addr:%x, ea:%x,%x,%x,%x\n",
459		laddr, sbdev->e_addr.manf_id, sbdev->e_addr.prod_code,
460		sbdev->e_addr.dev_index, sbdev->e_addr.instance);
461
462	return 0;
463
464err:
465	mutex_unlock(&ctrl->lock);
466	return ret;
467
468}
469
470/**
471 * slim_device_report_present() - Report enumerated device.
472 *
473 * @ctrl: Controller with which device is enumerated.
474 * @e_addr: Enumeration address of the device.
475 * @laddr: Return logical address (if valid flag is false)
476 *
477 * Called by controller in response to REPORT_PRESENT. Framework will assign
478 * a logical address to this enumeration address.
479 * Function returns -EXFULL to indicate that all logical addresses are already
480 * taken.
481 */
482int slim_device_report_present(struct slim_controller *ctrl,
483			       struct slim_eaddr *e_addr, u8 *laddr)
484{
485	struct slim_device *sbdev;
486	int ret;
487
488	ret = pm_runtime_get_sync(ctrl->dev);
489
490	if (ctrl->sched.clk_state != SLIM_CLK_ACTIVE) {
491		dev_err(ctrl->dev, "slim ctrl not active,state:%d, ret:%d\n",
492				    ctrl->sched.clk_state, ret);
493		goto out_put_rpm;
494	}
495
496	sbdev = slim_get_device(ctrl, e_addr);
497	if (IS_ERR(sbdev)) {
498		ret = -ENODEV;
499		goto out_put_rpm;
500	}
501
502	if (sbdev->is_laddr_valid) {
503		*laddr = sbdev->laddr;
504		ret = 0;
505	} else {
506		ret = slim_device_alloc_laddr(sbdev, true);
507	}
508
509	put_device(&sbdev->dev);
510out_put_rpm:
511	pm_runtime_mark_last_busy(ctrl->dev);
512	pm_runtime_put_autosuspend(ctrl->dev);
513	return ret;
514}
515EXPORT_SYMBOL_GPL(slim_device_report_present);
516
517/**
518 * slim_get_logical_addr() - get/allocate logical address of a SLIMbus device.
519 *
520 * @sbdev: client handle requesting the address.
521 *
522 * Return: zero if a logical address is valid or a new logical address
523 * has been assigned. error code in case of error.
524 */
525int slim_get_logical_addr(struct slim_device *sbdev)
526{
527	if (!sbdev->is_laddr_valid)
528		return slim_device_alloc_laddr(sbdev, false);
529
530	return 0;
531}
532EXPORT_SYMBOL_GPL(slim_get_logical_addr);
533
534static void __exit slimbus_exit(void)
535{
536	bus_unregister(&slimbus_bus);
537}
538module_exit(slimbus_exit);
539
540static int __init slimbus_init(void)
541{
542	return bus_register(&slimbus_bus);
543}
544postcore_initcall(slimbus_init);
545
546MODULE_LICENSE("GPL v2");
547MODULE_DESCRIPTION("SLIMbus core");