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
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
|
/*
* arch/arm/mach-ns9xxx/clock.c
*
* Copyright (C) 2007 by Digi International Inc.
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published by
* the Free Software Foundation.
*/
#include <linux/err.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/clk.h>
#include <linux/string.h>
#include <linux/platform_device.h>
#include <linux/semaphore.h>
#include "clock.h"
static LIST_HEAD(clocks);
static DEFINE_SPINLOCK(clk_lock);
struct clk *clk_get(struct device *dev, const char *id)
{
struct clk *p, *ret = NULL, *retgen = NULL;
unsigned long flags;
int idno;
if (dev == NULL || dev->bus != &platform_bus_type)
idno = -1;
else
idno = to_platform_device(dev)->id;
spin_lock_irqsave(&clk_lock, flags);
list_for_each_entry(p, &clocks, node) {
if (strcmp(id, p->name) == 0) {
if (p->id == idno) {
if (!try_module_get(p->owner))
continue;
ret = p;
break;
} else if (p->id == -1)
/* remember match with id == -1 in case there is
* no clock for idno */
retgen = p;
}
}
if (!ret && retgen && try_module_get(retgen->owner))
ret = retgen;
if (ret)
++ret->refcount;
spin_unlock_irqrestore(&clk_lock, flags);
return ret ? ret : ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL(clk_get);
void clk_put(struct clk *clk)
{
module_put(clk->owner);
--clk->refcount;
}
EXPORT_SYMBOL(clk_put);
static int clk_enable_unlocked(struct clk *clk)
{
int ret = 0;
if (clk->parent) {
ret = clk_enable_unlocked(clk->parent);
if (ret)
return ret;
}
if (clk->usage++ == 0 && clk->endisable)
ret = clk->endisable(clk, 1);
return ret;
}
int clk_enable(struct clk *clk)
{
int ret;
unsigned long flags;
spin_lock_irqsave(&clk_lock, flags);
ret = clk_enable_unlocked(clk);
spin_unlock_irqrestore(&clk_lock, flags);
return ret;
}
EXPORT_SYMBOL(clk_enable);
static void clk_disable_unlocked(struct clk *clk)
{
if (--clk->usage == 0 && clk->endisable)
clk->endisable(clk, 0);
if (clk->parent)
clk_disable_unlocked(clk->parent);
}
void clk_disable(struct clk *clk)
{
unsigned long flags;
spin_lock_irqsave(&clk_lock, flags);
clk_disable_unlocked(clk);
spin_unlock_irqrestore(&clk_lock, flags);
}
EXPORT_SYMBOL(clk_disable);
unsigned long clk_get_rate(struct clk *clk)
{
if (clk->get_rate)
return clk->get_rate(clk);
if (clk->rate)
return clk->rate;
if (clk->parent)
return clk_get_rate(clk->parent);
return 0;
}
EXPORT_SYMBOL(clk_get_rate);
int clk_register(struct clk *clk)
{
unsigned long flags;
spin_lock_irqsave(&clk_lock, flags);
list_add(&clk->node, &clocks);
if (clk->parent)
++clk->parent->refcount;
spin_unlock_irqrestore(&clk_lock, flags);
return 0;
}
int clk_unregister(struct clk *clk)
{
int ret = 0;
unsigned long flags;
spin_lock_irqsave(&clk_lock, flags);
if (clk->usage || clk->refcount)
ret = -EBUSY;
else
list_del(&clk->node);
if (clk->parent)
--clk->parent->refcount;
spin_unlock_irqrestore(&clk_lock, flags);
return ret;
}
#if defined CONFIG_DEBUG_FS
#include <linux/debugfs.h>
#include <linux/seq_file.h>
static int clk_debugfs_show(struct seq_file *s, void *null)
{
unsigned long flags;
struct clk *p;
spin_lock_irqsave(&clk_lock, flags);
list_for_each_entry(p, &clocks, node)
seq_printf(s, "%s.%d: usage=%lu refcount=%lu rate=%lu\n",
p->name, p->id, p->usage, p->refcount,
p->usage ? clk_get_rate(p) : 0);
spin_unlock_irqrestore(&clk_lock, flags);
return 0;
}
static int clk_debugfs_open(struct inode *inode, struct file *file)
{
return single_open(file, clk_debugfs_show, NULL);
}
static struct file_operations clk_debugfs_operations = {
.open = clk_debugfs_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int __init clk_debugfs_init(void)
{
struct dentry *dentry;
dentry = debugfs_create_file("clk", S_IFREG | S_IRUGO, NULL, NULL,
&clk_debugfs_operations);
return IS_ERR(dentry) ? PTR_ERR(dentry) : 0;
}
subsys_initcall(clk_debugfs_init);
#endif /* if defined CONFIG_DEBUG_FS */
|
