Merge the easy part of the IOP branch
[linux-2.6] / arch / avr32 / mach-at32ap / clock.c
1 /*
2  * Clock management for AT32AP CPUs
3  *
4  * Copyright (C) 2006 Atmel Corporation
5  *
6  * Based on arch/arm/mach-at91/clock.c
7  *   Copyright (C) 2005 David Brownell
8  *   Copyright (C) 2005 Ivan Kokshaysky
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License version 2 as
12  * published by the Free Software Foundation.
13  */
14 #include <linux/clk.h>
15 #include <linux/err.h>
16 #include <linux/device.h>
17 #include <linux/string.h>
18
19 #include "clock.h"
20
21 static spinlock_t clk_lock = SPIN_LOCK_UNLOCKED;
22
23 struct clk *clk_get(struct device *dev, const char *id)
24 {
25         int i;
26
27         for (i = 0; i < at32_nr_clocks; i++) {
28                 struct clk *clk = at32_clock_list[i];
29
30                 if (clk->dev == dev && strcmp(id, clk->name) == 0)
31                         return clk;
32         }
33
34         return ERR_PTR(-ENOENT);
35 }
36 EXPORT_SYMBOL(clk_get);
37
38 void clk_put(struct clk *clk)
39 {
40         /* clocks are static for now, we can't free them */
41 }
42 EXPORT_SYMBOL(clk_put);
43
44 static void __clk_enable(struct clk *clk)
45 {
46         if (clk->parent)
47                 __clk_enable(clk->parent);
48         if (clk->users++ == 0 && clk->mode)
49                 clk->mode(clk, 1);
50 }
51
52 int clk_enable(struct clk *clk)
53 {
54         unsigned long flags;
55
56         spin_lock_irqsave(&clk_lock, flags);
57         __clk_enable(clk);
58         spin_unlock_irqrestore(&clk_lock, flags);
59
60         return 0;
61 }
62 EXPORT_SYMBOL(clk_enable);
63
64 static void __clk_disable(struct clk *clk)
65 {
66         BUG_ON(clk->users == 0);
67
68         if (--clk->users == 0 && clk->mode)
69                 clk->mode(clk, 0);
70         if (clk->parent)
71                 __clk_disable(clk->parent);
72 }
73
74 void clk_disable(struct clk *clk)
75 {
76         unsigned long flags;
77
78         spin_lock_irqsave(&clk_lock, flags);
79         __clk_disable(clk);
80         spin_unlock_irqrestore(&clk_lock, flags);
81 }
82 EXPORT_SYMBOL(clk_disable);
83
84 unsigned long clk_get_rate(struct clk *clk)
85 {
86         unsigned long flags;
87         unsigned long rate;
88
89         spin_lock_irqsave(&clk_lock, flags);
90         rate = clk->get_rate(clk);
91         spin_unlock_irqrestore(&clk_lock, flags);
92
93         return rate;
94 }
95 EXPORT_SYMBOL(clk_get_rate);
96
97 long clk_round_rate(struct clk *clk, unsigned long rate)
98 {
99         unsigned long flags, actual_rate;
100
101         if (!clk->set_rate)
102                 return -ENOSYS;
103
104         spin_lock_irqsave(&clk_lock, flags);
105         actual_rate = clk->set_rate(clk, rate, 0);
106         spin_unlock_irqrestore(&clk_lock, flags);
107
108         return actual_rate;
109 }
110 EXPORT_SYMBOL(clk_round_rate);
111
112 int clk_set_rate(struct clk *clk, unsigned long rate)
113 {
114         unsigned long flags;
115         long ret;
116
117         if (!clk->set_rate)
118                 return -ENOSYS;
119
120         spin_lock_irqsave(&clk_lock, flags);
121         ret = clk->set_rate(clk, rate, 1);
122         spin_unlock_irqrestore(&clk_lock, flags);
123
124         return (ret < 0) ? ret : 0;
125 }
126 EXPORT_SYMBOL(clk_set_rate);
127
128 int clk_set_parent(struct clk *clk, struct clk *parent)
129 {
130         unsigned long flags;
131         int ret;
132
133         if (!clk->set_parent)
134                 return -ENOSYS;
135
136         spin_lock_irqsave(&clk_lock, flags);
137         ret = clk->set_parent(clk, parent);
138         spin_unlock_irqrestore(&clk_lock, flags);
139
140         return ret;
141 }
142 EXPORT_SYMBOL(clk_set_parent);
143
144 struct clk *clk_get_parent(struct clk *clk)
145 {
146         return clk->parent;
147 }
148 EXPORT_SYMBOL(clk_get_parent);