diff options
Diffstat (limited to 'arch/arm/common/clkdev.c')
-rw-r--r-- | arch/arm/common/clkdev.c | 128 |
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 --- /dev/null +++ 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 | |||
24 | static LIST_HEAD(clocks); | ||
25 | static DEFINE_MUTEX(clocks_mutex); | ||
26 | |||
27 | static 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 | |||
52 | struct 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 | } | ||
65 | EXPORT_SYMBOL(clk_get); | ||
66 | |||
67 | void clk_put(struct clk *clk) | ||
68 | { | ||
69 | __clk_put(clk); | ||
70 | } | ||
71 | EXPORT_SYMBOL(clk_put); | ||
72 | |||
73 | void 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 | } | ||
79 | EXPORT_SYMBOL(clkdev_add); | ||
80 | |||
81 | #define MAX_DEV_ID 20 | ||
82 | #define MAX_CON_ID 16 | ||
83 | |||
84 | struct clk_lookup_alloc { | ||
85 | struct clk_lookup cl; | ||
86 | char dev_id[MAX_DEV_ID]; | ||
87 | char con_id[MAX_CON_ID]; | ||
88 | }; | ||
89 | |||
90 | struct 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 | } | ||
116 | EXPORT_SYMBOL(clkdev_alloc); | ||
117 | |||
118 | /* | ||
119 | * clkdev_drop - remove a clock dynamically allocated | ||
120 | */ | ||
121 | void 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 | } | ||
128 | EXPORT_SYMBOL(clkdev_drop); | ||