clockdomain.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * OMAP clockdomain support
  4 *
  5 * Copyright (C) 2013 Texas Instruments, Inc.
  6 *
  7 * Tero Kristo <t-kristo@ti.com>
  8 */
  9
 10#include <linux/clk.h>
 11#include <linux/clk-provider.h>
 12#include <linux/slab.h>
 13#include <linux/of.h>
 14#include <linux/of_address.h>
 15#include <linux/clk/ti.h>
 16
 17#include "clock.h"
 18
 19#undef pr_fmt
 20#define pr_fmt(fmt) "%s: " fmt, __func__
 21
 22/**
 23 * omap2_clkops_enable_clkdm - increment usecount on clkdm of @hw
 24 * @hw: struct clk_hw * of the clock being enabled
 25 *
 26 * Increment the usecount of the clockdomain of the clock pointed to
 27 * by @hw; if the usecount is 1, the clockdomain will be "enabled."
 28 * Only needed for clocks that don't use omap2_dflt_clk_enable() as
 29 * their enable function pointer.  Passes along the return value of
 30 * clkdm_clk_enable(), -EINVAL if @hw is not associated with a
 31 * clockdomain, or 0 if clock framework-based clockdomain control is
 32 * not implemented.
 33 */
 34int omap2_clkops_enable_clkdm(struct clk_hw *hw)
 35{
 36	struct clk_hw_omap *clk;
 37	int ret = 0;
 38
 39	clk = to_clk_hw_omap(hw);
 40
 41	if (unlikely(!clk->clkdm)) {
 42		pr_err("%s: %s: no clkdm set ?!\n", __func__,
 43		       clk_hw_get_name(hw));
 44		return -EINVAL;
 45	}
 46
 47	if (ti_clk_get_features()->flags & TI_CLK_DISABLE_CLKDM_CONTROL) {
 48		pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
 49		       __func__, clk_hw_get_name(hw));
 50		return 0;
 51	}
 52
 53	ret = ti_clk_ll_ops->clkdm_clk_enable(clk->clkdm, hw->clk);
 54	WARN(ret, "%s: could not enable %s's clockdomain %s: %d\n",
 55	     __func__, clk_hw_get_name(hw), clk->clkdm_name, ret);
 56
 57	return ret;
 58}
 59
 60/**
 61 * omap2_clkops_disable_clkdm - decrement usecount on clkdm of @hw
 62 * @hw: struct clk_hw * of the clock being disabled
 63 *
 64 * Decrement the usecount of the clockdomain of the clock pointed to
 65 * by @hw; if the usecount is 0, the clockdomain will be "disabled."
 66 * Only needed for clocks that don't use omap2_dflt_clk_disable() as their
 67 * disable function pointer.  No return value.
 68 */
 69void omap2_clkops_disable_clkdm(struct clk_hw *hw)
 70{
 71	struct clk_hw_omap *clk;
 72
 73	clk = to_clk_hw_omap(hw);
 74
 75	if (unlikely(!clk->clkdm)) {
 76		pr_err("%s: %s: no clkdm set ?!\n", __func__,
 77		       clk_hw_get_name(hw));
 78		return;
 79	}
 80
 81	if (ti_clk_get_features()->flags & TI_CLK_DISABLE_CLKDM_CONTROL) {
 82		pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
 83		       __func__, clk_hw_get_name(hw));
 84		return;
 85	}
 86
 87	ti_clk_ll_ops->clkdm_clk_disable(clk->clkdm, hw->clk);
 88}
 89
 90/**
 91 * omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk
 92 * @hw: Pointer to clk_hw_omap used to obtain OMAP clock struct ptr to use
 93 *
 94 * Convert a clockdomain name stored in a struct clk 'clk' into a
 95 * clockdomain pointer, and save it into the struct clk.  Intended to be
 96 * called during clk_register(). Returns 0 on success, -EERROR otherwise.
 97 */
 98int omap2_init_clk_clkdm(struct clk_hw *hw)
 99{
100	struct clk_hw_omap *clk = to_clk_hw_omap(hw);
101	struct clockdomain *clkdm;
102	const char *clk_name;
103
104	if (!clk->clkdm_name)
105		return 0;
106
107	clk_name = __clk_get_name(hw->clk);
108
109	clkdm = ti_clk_ll_ops->clkdm_lookup(clk->clkdm_name);
110	if (clkdm) {
111		pr_debug("clock: associated clk %s to clkdm %s\n",
112			 clk_name, clk->clkdm_name);
113		clk->clkdm = clkdm;
114	} else {
115		pr_debug("clock: could not associate clk %s to clkdm %s\n",
116			 clk_name, clk->clkdm_name);
117	}
118
119	return 0;
120}
121
122static void __init of_ti_clockdomain_setup(struct device_node *node)
123{
124	struct clk *clk;
125	struct clk_hw *clk_hw;
126	const char *clkdm_name = ti_dt_clk_name(node);
127	int i;
128	unsigned int num_clks;
129
130	num_clks = of_clk_get_parent_count(node);
131
132	for (i = 0; i < num_clks; i++) {
133		clk = of_clk_get(node, i);
134		if (IS_ERR(clk)) {
135			pr_err("%s: Failed get %pOF' clock nr %d (%ld)\n",
136			       __func__, node, i, PTR_ERR(clk));
137			continue;
138		}
139		clk_hw = __clk_get_hw(clk);
140		if (!omap2_clk_is_hw_omap(clk_hw)) {
141			pr_warn("can't setup clkdm for basic clk %s\n",
142				__clk_get_name(clk));
143			clk_put(clk);
144			continue;
145		}
146		to_clk_hw_omap(clk_hw)->clkdm_name = clkdm_name;
147		omap2_init_clk_clkdm(clk_hw);
148		clk_put(clk);
149	}
150}
151
152static const struct of_device_id ti_clkdm_match_table[] __initconst = {
153	{ .compatible = "ti,clockdomain" },
154	{ }
155};
156
157/**
158 * ti_dt_clockdomains_setup - setup device tree clockdomains
159 *
160 * Initializes clockdomain nodes for a SoC. This parses through all the
161 * nodes with compatible = "ti,clockdomain", and add the clockdomain
162 * info for all the clocks listed under these. This function shall be
163 * called after rest of the DT clock init has completed and all
164 * clock nodes have been registered.
165 */
166void __init ti_dt_clockdomains_setup(void)
167{
168	struct device_node *np;
169	for_each_matching_node(np, ti_clkdm_match_table) {
170		of_ti_clockdomain_setup(np);
171	}
172}