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-rw-r--r--arch/arm/common/clkdev.c128
1 files changed, 128 insertions, 0 deletions
diff --git a/arch/arm/common/clkdev.c b/arch/arm/common/clkdev.c
new file mode 100644
index 000000000000..17a17b49a45b
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+++ b/arch/arm/common/clkdev.c
@@ -0,0 +1,128 @@
1/*
2 * arch/arm/common/clkdev.c
3 *
4 * Copyright (C) 2008 Russell King.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * Helper for the clk API to assist looking up a struct clk.
11 */
12#include <linux/module.h>
13#include <linux/kernel.h>
14#include <linux/device.h>
15#include <linux/list.h>
16#include <linux/errno.h>
17#include <linux/err.h>
18#include <linux/string.h>
19#include <linux/mutex.h>
20
21#include <asm/clkdev.h>
22#include <mach/clkdev.h>
23
24static LIST_HEAD(clocks);
25static DEFINE_MUTEX(clocks_mutex);
26
27static struct clk *clk_find(const char *dev_id, const char *con_id)
28{
29 struct clk_lookup *p;
30 struct clk *clk = NULL;
31 int match, best = 0;
32
33 list_for_each_entry(p, &clocks, node) {
34 if ((p->dev_id && !dev_id) || (p->con_id && !con_id))
35 continue;
36 match = 0;
37 if (p->dev_id)
38 match += 2 * (strcmp(p->dev_id, dev_id) == 0);
39 if (p->con_id)
40 match += 1 * (strcmp(p->con_id, con_id) == 0);
41 if (match == 0)
42 continue;
43
44 if (match > best) {
45 clk = p->clk;
46 best = match;
47 }
48 }
49 return clk;
50}
51
52struct clk *clk_get(struct device *dev, const char *con_id)
53{
54 const char *dev_id = dev ? dev_name(dev) : NULL;
55 struct clk *clk;
56
57 mutex_lock(&clocks_mutex);
58 clk = clk_find(dev_id, con_id);
59 if (clk && !__clk_get(clk))
60 clk = NULL;
61 mutex_unlock(&clocks_mutex);
62
63 return clk ? clk : ERR_PTR(-ENOENT);
64}
65EXPORT_SYMBOL(clk_get);
66
67void clk_put(struct clk *clk)
68{
69 __clk_put(clk);
70}
71EXPORT_SYMBOL(clk_put);
72
73void clkdev_add(struct clk_lookup *cl)
74{
75 mutex_lock(&clocks_mutex);
76 list_add_tail(&cl->node, &clocks);
77 mutex_unlock(&clocks_mutex);
78}
79EXPORT_SYMBOL(clkdev_add);
80
81#define MAX_DEV_ID 20
82#define MAX_CON_ID 16
83
84struct clk_lookup_alloc {
85 struct clk_lookup cl;
86 char dev_id[MAX_DEV_ID];
87 char con_id[MAX_CON_ID];
88};
89
90struct clk_lookup *clkdev_alloc(struct clk *clk, const char *con_id,
91 const char *dev_fmt, ...)
92{
93 struct clk_lookup_alloc *cla;
94
95 cla = kzalloc(sizeof(*cla), GFP_KERNEL);
96 if (!cla)
97 return NULL;
98
99 cla->cl.clk = clk;
100 if (con_id) {
101 strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
102 cla->cl.con_id = cla->con_id;
103 }
104
105 if (dev_fmt) {
106 va_list ap;
107
108 va_start(ap, dev_fmt);
109 vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
110 cla->cl.dev_id = cla->dev_id;
111 va_end(ap);
112 }
113
114 return &cla->cl;
115}
116EXPORT_SYMBOL(clkdev_alloc);
117
118/*
119 * clkdev_drop - remove a clock dynamically allocated
120 */
121void clkdev_drop(struct clk_lookup *cl)
122{
123 mutex_lock(&clocks_mutex);
124 list_del(&cl->node);
125 mutex_unlock(&clocks_mutex);
126 kfree(cl);
127}
128EXPORT_SYMBOL(clkdev_drop);