1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
/*
* linux/arch/arm/mach-sa1100/clock.c
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/clk.h>
#include <linux/spinlock.h>
#include <asm/hardware.h>
#include <asm/semaphore.h>
struct clk {
struct list_head node;
unsigned long rate;
struct module *owner;
const char *name;
unsigned int enabled;
void (*enable)(void);
void (*disable)(void);
};
static LIST_HEAD(clocks);
static DECLARE_MUTEX(clocks_sem);
static DEFINE_SPINLOCK(clocks_lock);
struct clk *clk_get(struct device *dev, const char *id)
{
struct clk *p, *clk = ERR_PTR(-ENOENT);
down(&clocks_sem);
list_for_each_entry(p, &clocks, node) {
if (strcmp(id, p->name) == 0 && try_module_get(p->owner)) {
clk = p;
break;
}
}
up(&clocks_sem);
return clk;
}
EXPORT_SYMBOL(clk_get);
void clk_put(struct clk *clk)
{
module_put(clk->owner);
}
EXPORT_SYMBOL(clk_put);
int clk_enable(struct clk *clk)
{
unsigned long flags;
spin_lock_irqsave(&clocks_lock, flags);
if (clk->enabled++ == 0)
clk->enable();
spin_unlock_irqrestore(&clocks_lock, flags);
return 0;
}
EXPORT_SYMBOL(clk_enable);
void clk_disable(struct clk *clk)
{
unsigned long flags;
WARN_ON(clk->enabled == 0);
spin_lock_irqsave(&clocks_lock, flags);
if (--clk->enabled == 0)
clk->disable();
spin_unlock_irqrestore(&clocks_lock, flags);
}
EXPORT_SYMBOL(clk_disable);
unsigned long clk_get_rate(struct clk *clk)
{
return clk->rate;
}
EXPORT_SYMBOL(clk_get_rate);
static void clk_gpio27_enable(void)
{
/*
* First, set up the 3.6864MHz clock on GPIO 27 for the SA-1111:
* (SA-1110 Developer's Manual, section 9.1.2.1)
*/
GAFR |= GPIO_32_768kHz;
GPDR |= GPIO_32_768kHz;
TUCR = TUCR_3_6864MHz;
}
static void clk_gpio27_disable(void)
{
TUCR = 0;
GPDR &= ~GPIO_32_768kHz;
GAFR &= ~GPIO_32_768kHz;
}
static struct clk clk_gpio27 = {
.name = "GPIO27_CLK",
.rate = 3686400,
.enable = clk_gpio27_enable,
.disable = clk_gpio27_disable,
};
int clk_register(struct clk *clk)
{
down(&clocks_sem);
list_add(&clk->node, &clocks);
up(&clocks_sem);
return 0;
}
EXPORT_SYMBOL(clk_register);
void clk_unregister(struct clk *clk)
{
down(&clocks_sem);
list_del(&clk->node);
up(&clocks_sem);
}
EXPORT_SYMBOL(clk_unregister);
static int __init clk_init(void)
{
clk_register(&clk_gpio27);
return 0;
}
arch_initcall(clk_init);
|
