1/*
2 *  linux/arch/arm/mach-sa1100/clock.c
3 */
4#include <linux/module.h>
5#include <linux/kernel.h>
6#include <linux/list.h>
7#include <linux/errno.h>
8#include <linux/err.h>
9#include <linux/string.h>
10#include <linux/clk.h>
11#include <linux/spinlock.h>
12
13#include <asm/arch/pxa-regs.h>
14#include <asm/hardware.h>
15#include <asm/semaphore.h>
16
17struct clk {
18	struct list_head	node;
19	unsigned long		rate;
20	struct module		*owner;
21	const char		*name;
22	unsigned int		enabled;
23	void			(*enable)(void);
24	void			(*disable)(void);
25};
26
27static LIST_HEAD(clocks);
28static DECLARE_MUTEX(clocks_sem);
29static DEFINE_SPINLOCK(clocks_lock);
30
31struct clk *clk_get(struct device *dev, const char *id)
32{
33	struct clk *p, *clk = ERR_PTR(-ENOENT);
34
35	down(&clocks_sem);
36	list_for_each_entry(p, &clocks, node) {
37		if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
38			clk = p;
39			break;
40		}
41	}
42	up(&clocks_sem);
43
44	return clk;
45}
46EXPORT_SYMBOL(clk_get);
47
48void clk_put(struct clk *clk)
49{
50	module_put(clk->owner);
51}
52EXPORT_SYMBOL(clk_put);
53
54int clk_enable(struct clk *clk)
55{
56	unsigned long flags;
57
58	spin_lock_irqsave(&clocks_lock, flags);
59	if (clk->enabled++ == 0)
60		clk->enable();
61	spin_unlock_irqrestore(&clocks_lock, flags);
62	return 0;
63}
64EXPORT_SYMBOL(clk_enable);
65
66void clk_disable(struct clk *clk)
67{
68	unsigned long flags;
69
70	WARN_ON(clk->enabled == 0);
71
72	spin_lock_irqsave(&clocks_lock, flags);
73	if (--clk->enabled == 0)
74		clk->disable();
75	spin_unlock_irqrestore(&clocks_lock, flags);
76}
77EXPORT_SYMBOL(clk_disable);
78
79unsigned long clk_get_rate(struct clk *clk)
80{
81	return clk->rate;
82}
83EXPORT_SYMBOL(clk_get_rate);
84
85
86static void clk_gpio27_enable(void)
87{
88	pxa_gpio_mode(GPIO11_3_6MHz_MD);
89}
90
91static void clk_gpio27_disable(void)
92{
93}
94
95static struct clk clk_gpio27 = {
96	.name		= "GPIO27_CLK",
97	.rate		= 3686400,
98	.enable		= clk_gpio27_enable,
99	.disable	= clk_gpio27_disable,
100};
101
102int clk_register(struct clk *clk)
103{
104	down(&clocks_sem);
105	list_add(&clk->node, &clocks);
106	up(&clocks_sem);
107	return 0;
108}
109EXPORT_SYMBOL(clk_register);
110
111void clk_unregister(struct clk *clk)
112{
113	down(&clocks_sem);
114	list_del(&clk->node);
115	up(&clocks_sem);
116}
117EXPORT_SYMBOL(clk_unregister);
118
119static int __init clk_init(void)
120{
121	clk_register(&clk_gpio27);
122	return 0;
123}
124arch_initcall(clk_init);
125