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 */
omap2_clkops_enable_clkdm(struct clk_hw * hw)34 int 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 */
omap2_clkops_disable_clkdm(struct clk_hw * hw)69 void 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 */
omap2_init_clk_clkdm(struct clk_hw * hw)98 int 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
of_ti_clockdomain_setup(struct device_node * node)122 static 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
152 static 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 */
ti_dt_clockdomains_setup(void)166 void __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 }
173