diff options
Diffstat (limited to 'arch/sh/kernel/clkdev.c')
-rw-r--r-- | arch/sh/kernel/clkdev.c | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/arch/sh/kernel/clkdev.c b/arch/sh/kernel/clkdev.c new file mode 100644 index 000000000000..29cd802ac388 --- /dev/null +++ b/arch/sh/kernel/clkdev.c | |||
@@ -0,0 +1,162 @@ | |||
1 | /* | ||
2 | * arch/sh/kernel/clkdev.c | ||
3 | * | ||
4 | * Cloned from arch/arm/common/clkdev.c: | ||
5 | * | ||
6 | * Copyright (C) 2008 Russell King. | ||
7 | * | ||
8 | * This program is free software; you can redistribute it and/or modify | ||
9 | * it under the terms of the GNU General Public License version 2 as | ||
10 | * published by the Free Software Foundation. | ||
11 | * | ||
12 | * Helper for the clk API to assist looking up a struct clk. | ||
13 | */ | ||
14 | #include <linux/module.h> | ||
15 | #include <linux/kernel.h> | ||
16 | #include <linux/device.h> | ||
17 | #include <linux/list.h> | ||
18 | #include <linux/errno.h> | ||
19 | #include <linux/err.h> | ||
20 | #include <linux/string.h> | ||
21 | #include <linux/mutex.h> | ||
22 | #include <linux/clk.h> | ||
23 | #include <asm/clock.h> | ||
24 | #include <asm/clkdev.h> | ||
25 | |||
26 | static LIST_HEAD(clocks); | ||
27 | static DEFINE_MUTEX(clocks_mutex); | ||
28 | |||
29 | /* | ||
30 | * Find the correct struct clk for the device and connection ID. | ||
31 | * We do slightly fuzzy matching here: | ||
32 | * An entry with a NULL ID is assumed to be a wildcard. | ||
33 | * If an entry has a device ID, it must match | ||
34 | * If an entry has a connection ID, it must match | ||
35 | * Then we take the most specific entry - with the following | ||
36 | * order of precidence: dev+con > dev only > con only. | ||
37 | */ | ||
38 | static struct clk *clk_find(const char *dev_id, const char *con_id) | ||
39 | { | ||
40 | struct clk_lookup *p; | ||
41 | struct clk *clk = NULL; | ||
42 | int match, best = 0; | ||
43 | |||
44 | list_for_each_entry(p, &clocks, node) { | ||
45 | match = 0; | ||
46 | if (p->dev_id) { | ||
47 | if (!dev_id || strcmp(p->dev_id, dev_id)) | ||
48 | continue; | ||
49 | match += 2; | ||
50 | } | ||
51 | if (p->con_id) { | ||
52 | if (!con_id || strcmp(p->con_id, con_id)) | ||
53 | continue; | ||
54 | match += 1; | ||
55 | } | ||
56 | if (match == 0) | ||
57 | continue; | ||
58 | |||
59 | if (match > best) { | ||
60 | clk = p->clk; | ||
61 | best = match; | ||
62 | } | ||
63 | } | ||
64 | return clk; | ||
65 | } | ||
66 | |||
67 | struct clk *clk_get_sys(const char *dev_id, const char *con_id) | ||
68 | { | ||
69 | struct clk *clk; | ||
70 | |||
71 | mutex_lock(&clocks_mutex); | ||
72 | clk = clk_find(dev_id, con_id); | ||
73 | mutex_unlock(&clocks_mutex); | ||
74 | |||
75 | return clk ? clk : ERR_PTR(-ENOENT); | ||
76 | } | ||
77 | EXPORT_SYMBOL(clk_get_sys); | ||
78 | |||
79 | void clkdev_add(struct clk_lookup *cl) | ||
80 | { | ||
81 | mutex_lock(&clocks_mutex); | ||
82 | list_add_tail(&cl->node, &clocks); | ||
83 | mutex_unlock(&clocks_mutex); | ||
84 | } | ||
85 | EXPORT_SYMBOL(clkdev_add); | ||
86 | |||
87 | void __init clkdev_add_table(struct clk_lookup *cl, size_t num) | ||
88 | { | ||
89 | mutex_lock(&clocks_mutex); | ||
90 | while (num--) { | ||
91 | list_add_tail(&cl->node, &clocks); | ||
92 | cl++; | ||
93 | } | ||
94 | mutex_unlock(&clocks_mutex); | ||
95 | } | ||
96 | |||
97 | #define MAX_DEV_ID 20 | ||
98 | #define MAX_CON_ID 16 | ||
99 | |||
100 | struct clk_lookup_alloc { | ||
101 | struct clk_lookup cl; | ||
102 | char dev_id[MAX_DEV_ID]; | ||
103 | char con_id[MAX_CON_ID]; | ||
104 | }; | ||
105 | |||
106 | struct clk_lookup *clkdev_alloc(struct clk *clk, const char *con_id, | ||
107 | const char *dev_fmt, ...) | ||
108 | { | ||
109 | struct clk_lookup_alloc *cla; | ||
110 | |||
111 | cla = kzalloc(sizeof(*cla), GFP_KERNEL); | ||
112 | if (!cla) | ||
113 | return NULL; | ||
114 | |||
115 | cla->cl.clk = clk; | ||
116 | if (con_id) { | ||
117 | strlcpy(cla->con_id, con_id, sizeof(cla->con_id)); | ||
118 | cla->cl.con_id = cla->con_id; | ||
119 | } | ||
120 | |||
121 | if (dev_fmt) { | ||
122 | va_list ap; | ||
123 | |||
124 | va_start(ap, dev_fmt); | ||
125 | vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap); | ||
126 | cla->cl.dev_id = cla->dev_id; | ||
127 | va_end(ap); | ||
128 | } | ||
129 | |||
130 | return &cla->cl; | ||
131 | } | ||
132 | EXPORT_SYMBOL(clkdev_alloc); | ||
133 | |||
134 | int clk_add_alias(const char *alias, const char *alias_dev_name, char *id, | ||
135 | struct device *dev) | ||
136 | { | ||
137 | struct clk *r = clk_get(dev, id); | ||
138 | struct clk_lookup *l; | ||
139 | |||
140 | if (IS_ERR(r)) | ||
141 | return PTR_ERR(r); | ||
142 | |||
143 | l = clkdev_alloc(r, alias, alias_dev_name); | ||
144 | clk_put(r); | ||
145 | if (!l) | ||
146 | return -ENODEV; | ||
147 | clkdev_add(l); | ||
148 | return 0; | ||
149 | } | ||
150 | EXPORT_SYMBOL(clk_add_alias); | ||
151 | |||
152 | /* | ||
153 | * clkdev_drop - remove a clock dynamically allocated | ||
154 | */ | ||
155 | void clkdev_drop(struct clk_lookup *cl) | ||
156 | { | ||
157 | mutex_lock(&clocks_mutex); | ||
158 | list_del(&cl->node); | ||
159 | mutex_unlock(&clocks_mutex); | ||
160 | kfree(cl); | ||
161 | } | ||
162 | EXPORT_SYMBOL(clkdev_drop); | ||