diff options
Diffstat (limited to 'arch/arm/plat-tcc/clock.c')
-rw-r--r-- | arch/arm/plat-tcc/clock.c | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/arch/arm/plat-tcc/clock.c b/arch/arm/plat-tcc/clock.c new file mode 100644 index 000000000000..f3ced10d5271 --- /dev/null +++ b/arch/arm/plat-tcc/clock.c | |||
@@ -0,0 +1,179 @@ | |||
1 | /* | ||
2 | * Clock framework for Telechips SoCs | ||
3 | * Based on arch/arm/plat-mxc/clock.c | ||
4 | * | ||
5 | * Copyright (C) 2004 - 2005 Nokia corporation | ||
6 | * Written by Tuukka Tikkanen <tuukka.tikkanen@elektrobit.com> | ||
7 | * Modified for omap shared clock framework by Tony Lindgren <tony@atomide.com> | ||
8 | * Copyright 2007 Freescale Semiconductor, Inc. All Rights Reserved. | ||
9 | * Copyright 2008 Juergen Beisert, kernel@pengutronix.de | ||
10 | * Copyright 2010 Hans J. Koch, hjk@linutronix.de | ||
11 | * | ||
12 | * Licensed under the terms of the GPL v2. | ||
13 | */ | ||
14 | |||
15 | #include <linux/clk.h> | ||
16 | #include <linux/err.h> | ||
17 | #include <linux/errno.h> | ||
18 | #include <linux/module.h> | ||
19 | #include <linux/mutex.h> | ||
20 | #include <linux/string.h> | ||
21 | |||
22 | #include <mach/clock.h> | ||
23 | #include <mach/hardware.h> | ||
24 | |||
25 | static DEFINE_MUTEX(clocks_mutex); | ||
26 | |||
27 | /*------------------------------------------------------------------------- | ||
28 | * Standard clock functions defined in include/linux/clk.h | ||
29 | *-------------------------------------------------------------------------*/ | ||
30 | |||
31 | static void __clk_disable(struct clk *clk) | ||
32 | { | ||
33 | BUG_ON(clk->refcount == 0); | ||
34 | |||
35 | if (!(--clk->refcount) && clk->disable) { | ||
36 | /* Unconditionally disable the clock in hardware */ | ||
37 | clk->disable(clk); | ||
38 | /* recursively disable parents */ | ||
39 | if (clk->parent) | ||
40 | __clk_disable(clk->parent); | ||
41 | } | ||
42 | } | ||
43 | |||
44 | static int __clk_enable(struct clk *clk) | ||
45 | { | ||
46 | int ret = 0; | ||
47 | |||
48 | if (clk->refcount++ == 0 && clk->enable) { | ||
49 | if (clk->parent) | ||
50 | ret = __clk_enable(clk->parent); | ||
51 | if (ret) | ||
52 | return ret; | ||
53 | else | ||
54 | return clk->enable(clk); | ||
55 | } | ||
56 | |||
57 | return 0; | ||
58 | } | ||
59 | |||
60 | /* This function increments the reference count on the clock and enables the | ||
61 | * clock if not already enabled. The parent clock tree is recursively enabled | ||
62 | */ | ||
63 | int clk_enable(struct clk *clk) | ||
64 | { | ||
65 | int ret = 0; | ||
66 | |||
67 | if (!clk) | ||
68 | return -EINVAL; | ||
69 | |||
70 | mutex_lock(&clocks_mutex); | ||
71 | ret = __clk_enable(clk); | ||
72 | mutex_unlock(&clocks_mutex); | ||
73 | |||
74 | return ret; | ||
75 | } | ||
76 | EXPORT_SYMBOL_GPL(clk_enable); | ||
77 | |||
78 | /* This function decrements the reference count on the clock and disables | ||
79 | * the clock when reference count is 0. The parent clock tree is | ||
80 | * recursively disabled | ||
81 | */ | ||
82 | void clk_disable(struct clk *clk) | ||
83 | { | ||
84 | if (!clk) | ||
85 | return; | ||
86 | |||
87 | mutex_lock(&clocks_mutex); | ||
88 | __clk_disable(clk); | ||
89 | mutex_unlock(&clocks_mutex); | ||
90 | } | ||
91 | EXPORT_SYMBOL_GPL(clk_disable); | ||
92 | |||
93 | /* Retrieve the *current* clock rate. If the clock itself | ||
94 | * does not provide a special calculation routine, ask | ||
95 | * its parent and so on, until one is able to return | ||
96 | * a valid clock rate | ||
97 | */ | ||
98 | unsigned long clk_get_rate(struct clk *clk) | ||
99 | { | ||
100 | if (!clk) | ||
101 | return 0UL; | ||
102 | |||
103 | if (clk->get_rate) | ||
104 | return clk->get_rate(clk); | ||
105 | |||
106 | return clk_get_rate(clk->parent); | ||
107 | } | ||
108 | EXPORT_SYMBOL_GPL(clk_get_rate); | ||
109 | |||
110 | /* Round the requested clock rate to the nearest supported | ||
111 | * rate that is less than or equal to the requested rate. | ||
112 | * This is dependent on the clock's current parent. | ||
113 | */ | ||
114 | long clk_round_rate(struct clk *clk, unsigned long rate) | ||
115 | { | ||
116 | if (!clk) | ||
117 | return 0; | ||
118 | if (!clk->round_rate) | ||
119 | return 0; | ||
120 | |||
121 | return clk->round_rate(clk, rate); | ||
122 | } | ||
123 | EXPORT_SYMBOL_GPL(clk_round_rate); | ||
124 | |||
125 | /* Set the clock to the requested clock rate. The rate must | ||
126 | * match a supported rate exactly based on what clk_round_rate returns | ||
127 | */ | ||
128 | int clk_set_rate(struct clk *clk, unsigned long rate) | ||
129 | { | ||
130 | int ret = -EINVAL; | ||
131 | |||
132 | if (!clk) | ||
133 | return ret; | ||
134 | if (!clk->set_rate || !rate) | ||
135 | return ret; | ||
136 | |||
137 | mutex_lock(&clocks_mutex); | ||
138 | ret = clk->set_rate(clk, rate); | ||
139 | mutex_unlock(&clocks_mutex); | ||
140 | |||
141 | return ret; | ||
142 | } | ||
143 | EXPORT_SYMBOL_GPL(clk_set_rate); | ||
144 | |||
145 | /* Set the clock's parent to another clock source */ | ||
146 | int clk_set_parent(struct clk *clk, struct clk *parent) | ||
147 | { | ||
148 | struct clk *old; | ||
149 | int ret = -EINVAL; | ||
150 | |||
151 | if (!clk) | ||
152 | return ret; | ||
153 | if (!clk->set_parent || !parent) | ||
154 | return ret; | ||
155 | |||
156 | mutex_lock(&clocks_mutex); | ||
157 | old = clk->parent; | ||
158 | if (clk->refcount) | ||
159 | __clk_enable(parent); | ||
160 | ret = clk->set_parent(clk, parent); | ||
161 | if (ret) | ||
162 | old = parent; | ||
163 | if (clk->refcount) | ||
164 | __clk_disable(old); | ||
165 | mutex_unlock(&clocks_mutex); | ||
166 | |||
167 | return ret; | ||
168 | } | ||
169 | EXPORT_SYMBOL_GPL(clk_set_parent); | ||
170 | |||
171 | /* Retrieve the clock's parent clock source */ | ||
172 | struct clk *clk_get_parent(struct clk *clk) | ||
173 | { | ||
174 | if (!clk) | ||
175 | return NULL; | ||
176 | |||
177 | return clk->parent; | ||
178 | } | ||
179 | EXPORT_SYMBOL_GPL(clk_get_parent); | ||