1 /*
2 * OMAP clockdomain support
3 *
4 * Copyright (C) 2013 Texas Instruments, Inc.
5 *
6 * Tero Kristo <t-kristo@ti.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
13 * kind, whether express or implied; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 */
17
18 #include <linux/clk.h>
19 #include <linux/clk-provider.h>
20 #include <linux/slab.h>
21 #include <linux/of.h>
22 #include <linux/of_address.h>
23 #include <linux/clk/ti.h>
24
25 #include "clock.h"
26
27 #undef pr_fmt
28 #define pr_fmt(fmt) "%s: " fmt, __func__
29
30 /**
31 * omap2_clkops_enable_clkdm - increment usecount on clkdm of @hw
32 * @hw: struct clk_hw * of the clock being enabled
33 *
34 * Increment the usecount of the clockdomain of the clock pointed to
35 * by @hw; if the usecount is 1, the clockdomain will be "enabled."
36 * Only needed for clocks that don't use omap2_dflt_clk_enable() as
37 * their enable function pointer. Passes along the return value of
38 * clkdm_clk_enable(), -EINVAL if @hw is not associated with a
39 * clockdomain, or 0 if clock framework-based clockdomain control is
40 * not implemented.
41 */
omap2_clkops_enable_clkdm(struct clk_hw * hw)42 int omap2_clkops_enable_clkdm(struct clk_hw *hw)
43 {
44 struct clk_hw_omap *clk;
45 int ret = 0;
46
47 clk = to_clk_hw_omap(hw);
48
49 if (unlikely(!clk->clkdm)) {
50 pr_err("%s: %s: no clkdm set ?!\n", __func__,
51 clk_hw_get_name(hw));
52 return -EINVAL;
53 }
54
55 if (ti_clk_get_features()->flags & TI_CLK_DISABLE_CLKDM_CONTROL) {
56 pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
57 __func__, clk_hw_get_name(hw));
58 return 0;
59 }
60
61 ret = ti_clk_ll_ops->clkdm_clk_enable(clk->clkdm, hw->clk);
62 WARN(ret, "%s: could not enable %s's clockdomain %s: %d\n",
63 __func__, clk_hw_get_name(hw), clk->clkdm_name, ret);
64
65 return ret;
66 }
67
68 /**
69 * omap2_clkops_disable_clkdm - decrement usecount on clkdm of @hw
70 * @hw: struct clk_hw * of the clock being disabled
71 *
72 * Decrement the usecount of the clockdomain of the clock pointed to
73 * by @hw; if the usecount is 0, the clockdomain will be "disabled."
74 * Only needed for clocks that don't use omap2_dflt_clk_disable() as their
75 * disable function pointer. No return value.
76 */
omap2_clkops_disable_clkdm(struct clk_hw * hw)77 void omap2_clkops_disable_clkdm(struct clk_hw *hw)
78 {
79 struct clk_hw_omap *clk;
80
81 clk = to_clk_hw_omap(hw);
82
83 if (unlikely(!clk->clkdm)) {
84 pr_err("%s: %s: no clkdm set ?!\n", __func__,
85 clk_hw_get_name(hw));
86 return;
87 }
88
89 if (ti_clk_get_features()->flags & TI_CLK_DISABLE_CLKDM_CONTROL) {
90 pr_err("%s: %s: clkfw-based clockdomain control disabled ?!\n",
91 __func__, clk_hw_get_name(hw));
92 return;
93 }
94
95 ti_clk_ll_ops->clkdm_clk_disable(clk->clkdm, hw->clk);
96 }
97
98 /**
99 * omap2_init_clk_clkdm - look up a clockdomain name, store pointer in clk
100 * @clk: OMAP clock struct ptr to use
101 *
102 * Convert a clockdomain name stored in a struct clk 'clk' into a
103 * clockdomain pointer, and save it into the struct clk. Intended to be
104 * called during clk_register(). Returns 0 on success, -EERROR otherwise.
105 */
omap2_init_clk_clkdm(struct clk_hw * hw)106 int omap2_init_clk_clkdm(struct clk_hw *hw)
107 {
108 struct clk_hw_omap *clk = to_clk_hw_omap(hw);
109 struct clockdomain *clkdm;
110 const char *clk_name;
111
112 if (!clk->clkdm_name)
113 return 0;
114
115 clk_name = __clk_get_name(hw->clk);
116
117 clkdm = ti_clk_ll_ops->clkdm_lookup(clk->clkdm_name);
118 if (clkdm) {
119 pr_debug("clock: associated clk %s to clkdm %s\n",
120 clk_name, clk->clkdm_name);
121 clk->clkdm = clkdm;
122 } else {
123 pr_debug("clock: could not associate clk %s to clkdm %s\n",
124 clk_name, clk->clkdm_name);
125 }
126
127 return 0;
128 }
129
of_ti_clockdomain_setup(struct device_node * node)130 static void __init of_ti_clockdomain_setup(struct device_node *node)
131 {
132 struct clk *clk;
133 struct clk_hw *clk_hw;
134 const char *clkdm_name = node->name;
135 int i;
136 unsigned int num_clks;
137
138 num_clks = of_clk_get_parent_count(node);
139
140 for (i = 0; i < num_clks; i++) {
141 clk = of_clk_get(node, i);
142 if (IS_ERR(clk)) {
143 pr_err("%s: Failed get %pOF' clock nr %d (%ld)\n",
144 __func__, node, i, PTR_ERR(clk));
145 continue;
146 }
147 clk_hw = __clk_get_hw(clk);
148 if (!omap2_clk_is_hw_omap(clk_hw)) {
149 pr_warn("can't setup clkdm for basic clk %s\n",
150 __clk_get_name(clk));
151 clk_put(clk);
152 continue;
153 }
154 to_clk_hw_omap(clk_hw)->clkdm_name = clkdm_name;
155 omap2_init_clk_clkdm(clk_hw);
156 clk_put(clk);
157 }
158 }
159
160 static const struct of_device_id ti_clkdm_match_table[] __initconst = {
161 { .compatible = "ti,clockdomain" },
162 { }
163 };
164
165 /**
166 * ti_dt_clockdomains_setup - setup device tree clockdomains
167 *
168 * Initializes clockdomain nodes for a SoC. This parses through all the
169 * nodes with compatible = "ti,clockdomain", and add the clockdomain
170 * info for all the clocks listed under these. This function shall be
171 * called after rest of the DT clock init has completed and all
172 * clock nodes have been registered.
173 */
ti_dt_clockdomains_setup(void)174 void __init ti_dt_clockdomains_setup(void)
175 {
176 struct device_node *np;
177 for_each_matching_node(np, ti_clkdm_match_table) {
178 of_ti_clockdomain_setup(np);
179 }
180 }
181
