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9d9f78ed MT |
1 | /* |
2 | * Copyright (C) 2010-2011 Canonical Ltd <jeremy.kerr@canonical.com> | |
3 | * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * Fixed rate clock implementation | |
10 | */ | |
11 | ||
12 | #include <linux/clk-provider.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/io.h> | |
16 | #include <linux/err.h> | |
015ba402 | 17 | #include <linux/of.h> |
9d9f78ed MT |
18 | |
19 | /* | |
20 | * DOC: basic fixed-rate clock that cannot gate | |
21 | * | |
22 | * Traits of this clock: | |
23 | * prepare - clk_(un)prepare only ensures parents are prepared | |
24 | * enable - clk_enable only ensures parents are enabled | |
25 | * rate - rate is always a fixed value. No clk_set_rate support | |
26 | * parent - fixed parent. No clk_set_parent support | |
27 | */ | |
28 | ||
29 | #define to_clk_fixed_rate(_hw) container_of(_hw, struct clk_fixed_rate, hw) | |
30 | ||
31 | static unsigned long clk_fixed_rate_recalc_rate(struct clk_hw *hw, | |
32 | unsigned long parent_rate) | |
33 | { | |
34 | return to_clk_fixed_rate(hw)->fixed_rate; | |
35 | } | |
9d9f78ed | 36 | |
0903ea60 BB |
37 | static unsigned long clk_fixed_rate_recalc_accuracy(struct clk_hw *hw, |
38 | unsigned long parent_accuracy) | |
39 | { | |
40 | return to_clk_fixed_rate(hw)->fixed_accuracy; | |
41 | } | |
42 | ||
822c250e | 43 | const struct clk_ops clk_fixed_rate_ops = { |
9d9f78ed | 44 | .recalc_rate = clk_fixed_rate_recalc_rate, |
0903ea60 | 45 | .recalc_accuracy = clk_fixed_rate_recalc_accuracy, |
9d9f78ed MT |
46 | }; |
47 | EXPORT_SYMBOL_GPL(clk_fixed_rate_ops); | |
48 | ||
27d54591 | 49 | /** |
0903ea60 BB |
50 | * clk_register_fixed_rate_with_accuracy - register fixed-rate clock with the |
51 | * clock framework | |
27d54591 MT |
52 | * @dev: device that is registering this clock |
53 | * @name: name of this clock | |
54 | * @parent_name: name of clock's parent | |
55 | * @flags: framework-specific flags | |
56 | * @fixed_rate: non-adjustable clock rate | |
0903ea60 | 57 | * @fixed_accuracy: non-adjustable clock rate |
27d54591 | 58 | */ |
0903ea60 BB |
59 | struct clk *clk_register_fixed_rate_with_accuracy(struct device *dev, |
60 | const char *name, const char *parent_name, unsigned long flags, | |
61 | unsigned long fixed_rate, unsigned long fixed_accuracy) | |
9d9f78ed MT |
62 | { |
63 | struct clk_fixed_rate *fixed; | |
27d54591 | 64 | struct clk *clk; |
0197b3ea | 65 | struct clk_init_data init; |
9d9f78ed | 66 | |
27d54591 | 67 | /* allocate fixed-rate clock */ |
9d9f78ed | 68 | fixed = kzalloc(sizeof(struct clk_fixed_rate), GFP_KERNEL); |
9d9f78ed MT |
69 | if (!fixed) { |
70 | pr_err("%s: could not allocate fixed clk\n", __func__); | |
71 | return ERR_PTR(-ENOMEM); | |
72 | } | |
73 | ||
0197b3ea SK |
74 | init.name = name; |
75 | init.ops = &clk_fixed_rate_ops; | |
f7d8caad | 76 | init.flags = flags | CLK_IS_BASIC; |
0197b3ea SK |
77 | init.parent_names = (parent_name ? &parent_name: NULL); |
78 | init.num_parents = (parent_name ? 1 : 0); | |
79 | ||
9d9f78ed MT |
80 | /* struct clk_fixed_rate assignments */ |
81 | fixed->fixed_rate = fixed_rate; | |
0903ea60 | 82 | fixed->fixed_accuracy = fixed_accuracy; |
0197b3ea | 83 | fixed->hw.init = &init; |
9d9f78ed | 84 | |
27d54591 | 85 | /* register the clock */ |
0197b3ea | 86 | clk = clk_register(dev, &fixed->hw); |
27d54591 MT |
87 | if (IS_ERR(clk)) |
88 | kfree(fixed); | |
89 | ||
90 | return clk; | |
9d9f78ed | 91 | } |
0903ea60 BB |
92 | EXPORT_SYMBOL_GPL(clk_register_fixed_rate_with_accuracy); |
93 | ||
94 | /** | |
95 | * clk_register_fixed_rate - register fixed-rate clock with the clock framework | |
96 | * @dev: device that is registering this clock | |
97 | * @name: name of this clock | |
98 | * @parent_name: name of clock's parent | |
99 | * @flags: framework-specific flags | |
100 | * @fixed_rate: non-adjustable clock rate | |
101 | */ | |
102 | struct clk *clk_register_fixed_rate(struct device *dev, const char *name, | |
103 | const char *parent_name, unsigned long flags, | |
104 | unsigned long fixed_rate) | |
105 | { | |
106 | return clk_register_fixed_rate_with_accuracy(dev, name, parent_name, | |
107 | flags, fixed_rate, 0); | |
108 | } | |
389ae05f | 109 | EXPORT_SYMBOL_GPL(clk_register_fixed_rate); |
015ba402 GL |
110 | |
111 | #ifdef CONFIG_OF | |
112 | /** | |
113 | * of_fixed_clk_setup() - Setup function for simple fixed rate clock | |
114 | */ | |
e4eda8e0 | 115 | void of_fixed_clk_setup(struct device_node *node) |
015ba402 GL |
116 | { |
117 | struct clk *clk; | |
118 | const char *clk_name = node->name; | |
119 | u32 rate; | |
0903ea60 | 120 | u32 accuracy = 0; |
015ba402 GL |
121 | |
122 | if (of_property_read_u32(node, "clock-frequency", &rate)) | |
123 | return; | |
124 | ||
0903ea60 BB |
125 | of_property_read_u32(node, "clock-accuracy", &accuracy); |
126 | ||
015ba402 GL |
127 | of_property_read_string(node, "clock-output-names", &clk_name); |
128 | ||
0903ea60 BB |
129 | clk = clk_register_fixed_rate_with_accuracy(NULL, clk_name, NULL, |
130 | CLK_IS_ROOT, rate, | |
131 | accuracy); | |
cdfed3b2 | 132 | if (!IS_ERR(clk)) |
015ba402 GL |
133 | of_clk_add_provider(node, of_clk_src_simple_get, clk); |
134 | } | |
135 | EXPORT_SYMBOL_GPL(of_fixed_clk_setup); | |
f2f6c255 | 136 | CLK_OF_DECLARE(fixed_clk, "fixed-clock", of_fixed_clk_setup); |
015ba402 | 137 | #endif |