Merge branch 'master'
[linux-2.6] / arch / arm / mach-versatile / clock.c
1 /*
2  *  linux/arch/arm/mach-versatile/clock.c
3  *
4  *  Copyright (C) 2004 ARM Limited.
5  *  Written by Deep Blue Solutions Limited.
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/list.h>
14 #include <linux/errno.h>
15 #include <linux/err.h>
16 #include <linux/string.h>
17
18 #include <asm/semaphore.h>
19 #include <asm/hardware/clock.h>
20 #include <asm/hardware/icst307.h>
21
22 #include "clock.h"
23
24 static LIST_HEAD(clocks);
25 static DECLARE_MUTEX(clocks_sem);
26
27 struct clk *clk_get(struct device *dev, const char *id)
28 {
29         struct clk *p, *clk = ERR_PTR(-ENOENT);
30
31         down(&clocks_sem);
32         list_for_each_entry(p, &clocks, node) {
33                 if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
34                         clk = p;
35                         break;
36                 }
37         }
38         up(&clocks_sem);
39
40         return clk;
41 }
42 EXPORT_SYMBOL(clk_get);
43
44 void clk_put(struct clk *clk)
45 {
46         module_put(clk->owner);
47 }
48 EXPORT_SYMBOL(clk_put);
49
50 int clk_enable(struct clk *clk)
51 {
52         return 0;
53 }
54 EXPORT_SYMBOL(clk_enable);
55
56 void clk_disable(struct clk *clk)
57 {
58 }
59 EXPORT_SYMBOL(clk_disable);
60
61 int clk_use(struct clk *clk)
62 {
63         return 0;
64 }
65 EXPORT_SYMBOL(clk_use);
66
67 void clk_unuse(struct clk *clk)
68 {
69 }
70 EXPORT_SYMBOL(clk_unuse);
71
72 unsigned long clk_get_rate(struct clk *clk)
73 {
74         return clk->rate;
75 }
76 EXPORT_SYMBOL(clk_get_rate);
77
78 long clk_round_rate(struct clk *clk, unsigned long rate)
79 {
80         return rate;
81 }
82 EXPORT_SYMBOL(clk_round_rate);
83
84 int clk_set_rate(struct clk *clk, unsigned long rate)
85 {
86         int ret = -EIO;
87
88         if (clk->setvco) {
89                 struct icst307_vco vco;
90
91                 vco = icst307_khz_to_vco(clk->params, rate / 1000);
92                 clk->rate = icst307_khz(clk->params, vco) * 1000;
93
94                 printk("Clock %s: setting VCO reg params: S=%d R=%d V=%d\n",
95                         clk->name, vco.s, vco.r, vco.v);
96
97                 clk->setvco(clk, vco);
98                 ret = 0;
99         }
100         return ret;
101 }
102 EXPORT_SYMBOL(clk_set_rate);
103
104 /*
105  * These are fixed clocks.
106  */
107 static struct clk kmi_clk = {
108         .name   = "KMIREFCLK",
109         .rate   = 24000000,
110 };
111
112 static struct clk uart_clk = {
113         .name   = "UARTCLK",
114         .rate   = 24000000,
115 };
116
117 static struct clk mmci_clk = {
118         .name   = "MCLK",
119         .rate   = 33000000,
120 };
121
122 int clk_register(struct clk *clk)
123 {
124         down(&clocks_sem);
125         list_add(&clk->node, &clocks);
126         up(&clocks_sem);
127         return 0;
128 }
129 EXPORT_SYMBOL(clk_register);
130
131 void clk_unregister(struct clk *clk)
132 {
133         down(&clocks_sem);
134         list_del(&clk->node);
135         up(&clocks_sem);
136 }
137 EXPORT_SYMBOL(clk_unregister);
138
139 static int __init clk_init(void)
140 {
141         clk_register(&kmi_clk);
142         clk_register(&uart_clk);
143         clk_register(&mmci_clk);
144         return 0;
145 }
146 arch_initcall(clk_init);