[AVR32] Warn, don't BUG if clk_disable is called too many times
[linux-2.6.git] / 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-at91rm9200/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         if (clk->users == 0) {
67                 printk(KERN_ERR "%s: mismatched disable\n", clk->name);
68                 WARN_ON(1);
69                 return;
70         }
71
72         if (--clk->users == 0 && clk->mode)
73                 clk->mode(clk, 0);
74         if (clk->parent)
75                 __clk_disable(clk->parent);
76 }
77
78 void clk_disable(struct clk *clk)
79 {
80         unsigned long flags;
81
82         spin_lock_irqsave(&clk_lock, flags);
83         __clk_disable(clk);
84         spin_unlock_irqrestore(&clk_lock, flags);
85 }
86 EXPORT_SYMBOL(clk_disable);
87
88 unsigned long clk_get_rate(struct clk *clk)
89 {
90         unsigned long flags;
91         unsigned long rate;
92
93         spin_lock_irqsave(&clk_lock, flags);
94         rate = clk->get_rate(clk);
95         spin_unlock_irqrestore(&clk_lock, flags);
96
97         return rate;
98 }
99 EXPORT_SYMBOL(clk_get_rate);
100
101 long clk_round_rate(struct clk *clk, unsigned long rate)
102 {
103         unsigned long flags, actual_rate;
104
105         if (!clk->set_rate)
106                 return -ENOSYS;
107
108         spin_lock_irqsave(&clk_lock, flags);
109         actual_rate = clk->set_rate(clk, rate, 0);
110         spin_unlock_irqrestore(&clk_lock, flags);
111
112         return actual_rate;
113 }
114 EXPORT_SYMBOL(clk_round_rate);
115
116 int clk_set_rate(struct clk *clk, unsigned long rate)
117 {
118         unsigned long flags;
119         long ret;
120
121         if (!clk->set_rate)
122                 return -ENOSYS;
123
124         spin_lock_irqsave(&clk_lock, flags);
125         ret = clk->set_rate(clk, rate, 1);
126         spin_unlock_irqrestore(&clk_lock, flags);
127
128         return (ret < 0) ? ret : 0;
129 }
130 EXPORT_SYMBOL(clk_set_rate);
131
132 int clk_set_parent(struct clk *clk, struct clk *parent)
133 {
134         unsigned long flags;
135         int ret;
136
137         if (!clk->set_parent)
138                 return -ENOSYS;
139
140         spin_lock_irqsave(&clk_lock, flags);
141         ret = clk->set_parent(clk, parent);
142         spin_unlock_irqrestore(&clk_lock, flags);
143
144         return ret;
145 }
146 EXPORT_SYMBOL(clk_set_parent);
147
148 struct clk *clk_get_parent(struct clk *clk)
149 {
150         return clk->parent;
151 }
152 EXPORT_SYMBOL(clk_get_parent);