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
|
/*
* arch/arm/common/clkdev.c
*
* Copyright (C) 2008 Russell King.
*
* 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.
*
* Helper for the clk API to assist looking up a struct clk.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/mutex.h>
#include <linux/clk.h>
#include <asm/clkdev.h>
#include <mach/clkdev.h>
static LIST_HEAD(clocks);
static DEFINE_MUTEX(clocks_mutex);
/*
* Find the correct struct clk for the device and connection ID.
* We do slightly fuzzy matching here:
* An entry with a NULL ID is assumed to be a wildcard.
* If an entry has a device ID, it must match
* If an entry has a connection ID, it must match
* Then we take the most specific entry - with the following
* order of precedence: dev+con > dev only > con only.
*/
static struct clk *clk_find(const char *dev_id, const char *con_id)
{
struct clk_lookup *p;
struct clk *clk = NULL;
int match, best = 0;
list_for_each_entry(p, &clocks, node) {
match = 0;
if (p->dev_id) {
if (!dev_id || strcmp(p->dev_id, dev_id))
continue;
match += 2;
}
if (p->con_id) {
if (!con_id || strcmp(p->con_id, con_id))
continue;
match += 1;
}
if (match == 0)
continue;
if (match > best) {
clk = p->clk;
best = match;
}
}
return clk;
}
struct clk *clk_get_sys(const char *dev_id, const char *con_id)
{
struct clk *clk;
mutex_lock(&clocks_mutex);
clk = clk_find(dev_id, con_id);
if (clk && !__clk_get(clk))
clk = NULL;
mutex_unlock(&clocks_mutex);
return clk ? clk : ERR_PTR(-ENOENT);
}
EXPORT_SYMBOL(clk_get_sys);
struct clk *clk_get(struct device *dev, const char *con_id)
{
const char *dev_id = dev ? dev_name(dev) : NULL;
return clk_get_sys(dev_id, con_id);
}
EXPORT_SYMBOL(clk_get);
void clk_put(struct clk *clk)
{
__clk_put(clk);
}
EXPORT_SYMBOL(clk_put);
void clkdev_add(struct clk_lookup *cl)
{
mutex_lock(&clocks_mutex);
list_add_tail(&cl->node, &clocks);
mutex_unlock(&clocks_mutex);
}
EXPORT_SYMBOL(clkdev_add);
#define MAX_DEV_ID 20
#define MAX_CON_ID 16
struct clk_lookup_alloc {
struct clk_lookup cl;
char dev_id[MAX_DEV_ID];
char con_id[MAX_CON_ID];
};
struct clk_lookup *clkdev_alloc(struct clk *clk, const char *con_id,
const char *dev_fmt, ...)
{
struct clk_lookup_alloc *cla;
cla = kzalloc(sizeof(*cla), GFP_KERNEL);
if (!cla)
return NULL;
cla->cl.clk = clk;
if (con_id) {
strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
cla->cl.con_id = cla->con_id;
}
if (dev_fmt) {
va_list ap;
va_start(ap, dev_fmt);
vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
cla->cl.dev_id = cla->dev_id;
va_end(ap);
}
return &cla->cl;
}
EXPORT_SYMBOL(clkdev_alloc);
int clk_add_alias(const char *alias, const char *alias_dev_name, char *id,
struct device *dev)
{
struct clk *r = clk_get(dev, id);
struct clk_lookup *l;
if (IS_ERR(r))
return PTR_ERR(r);
l = clkdev_alloc(r, alias, alias_dev_name);
clk_put(r);
if (!l)
return -ENODEV;
clkdev_add(l);
return 0;
}
EXPORT_SYMBOL(clk_add_alias);
/*
* clkdev_drop - remove a clock dynamically allocated
*/
void clkdev_drop(struct clk_lookup *cl)
{
mutex_lock(&clocks_mutex);
list_del(&cl->node);
mutex_unlock(&clocks_mutex);
kfree(cl);
}
EXPORT_SYMBOL(clkdev_drop);
|
