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#include <linux/mutex.h>
13
14#include <asm/hardware.h>
15
16/*
17 * Very simple clock implementation - we only have one clock to
18 * deal with at the moment, so we only match using the "name".
19 */
20struct clk {
21	struct list_head	node;
22	unsigned long		rate;
23	const char		*name;
24	unsigned int		enabled;
25	void			(*enable)(void);
26	void			(*disable)(void);
27};
28
29static LIST_HEAD(clocks);
30static DEFINE_MUTEX(clocks_mutex);
31static DEFINE_SPINLOCK(clocks_lock);
32
33struct clk *clk_get(struct device *dev, const char *id)
34{
35	struct clk *p, *clk = ERR_PTR(-ENOENT);
36
37	mutex_lock(&clocks_mutex);
38	list_for_each_entry(p, &clocks, node) {
39		if (strcmp(id, p->name) == 0) {
40			clk = p;
41			break;
42		}
43	}
44	mutex_unlock(&clocks_mutex);
45
46	return clk;
47}
48EXPORT_SYMBOL(clk_get);
49
50void clk_put(struct clk *clk)
51{
52}
53EXPORT_SYMBOL(clk_put);
54
55int clk_enable(struct clk *clk)
56{
57	unsigned long flags;
58
59	spin_lock_irqsave(&clocks_lock, flags);
60	if (clk->enabled++ == 0)
61		clk->enable();
62	spin_unlock_irqrestore(&clocks_lock, flags);
63	return 0;
64}
65EXPORT_SYMBOL(clk_enable);
66
67void clk_disable(struct clk *clk)
68{
69	unsigned long flags;
70
71	WARN_ON(clk->enabled == 0);
72
73	spin_lock_irqsave(&clocks_lock, flags);
74	if (--clk->enabled == 0)
75		clk->disable();
76	spin_unlock_irqrestore(&clocks_lock, flags);
77}
78EXPORT_SYMBOL(clk_disable);
79
80unsigned long clk_get_rate(struct clk *clk)
81{
82	return clk->rate;
83}
84EXPORT_SYMBOL(clk_get_rate);
85
86
87static void clk_gpio27_enable(void)
88{
89	/*
90	 * First, set up the 3.6864MHz clock on GPIO 27 for the SA-1111:
91	 * (SA-1110 Developer's Manual, section 9.1.2.1)
92	 */
93	GAFR |= GPIO_32_768kHz;
94	GPDR |= GPIO_32_768kHz;
95	TUCR = TUCR_3_6864MHz;
96}
97
98static void clk_gpio27_disable(void)
99{
100	TUCR = 0;
101	GPDR &= ~GPIO_32_768kHz;
102	GAFR &= ~GPIO_32_768kHz;
103}
104
105static struct clk clk_gpio27 = {
106	.name		= "GPIO27_CLK",
107	.rate		= 3686400,
108	.enable		= clk_gpio27_enable,
109	.disable	= clk_gpio27_disable,
110};
111
112int clk_register(struct clk *clk)
113{
114	mutex_lock(&clocks_mutex);
115	list_add(&clk->node, &clocks);
116	mutex_unlock(&clocks_mutex);
117	return 0;
118}
119EXPORT_SYMBOL(clk_register);
120
121void clk_unregister(struct clk *clk)
122{
123	mutex_lock(&clocks_mutex);
124	list_del(&clk->node);
125	mutex_unlock(&clocks_mutex);
126}
127EXPORT_SYMBOL(clk_unregister);
128
129static int __init clk_init(void)
130{
131	clk_register(&clk_gpio27);
132	return 0;
133}
134arch_initcall(clk_init);
135