Commit | Line | Data |
---|---|---|
0318e693 | 1 | /* |
6d803ba7 | 2 | * drivers/clk/clkdev.c |
0318e693 RK |
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> | |
c0c60c4b | 20 | #include <linux/clk.h> |
6d803ba7 | 21 | #include <linux/clkdev.h> |
0318e693 RK |
22 | |
23 | static LIST_HEAD(clocks); | |
24 | static DEFINE_MUTEX(clocks_mutex); | |
25 | ||
409dc360 RK |
26 | /* |
27 | * Find the correct struct clk for the device and connection ID. | |
28 | * We do slightly fuzzy matching here: | |
29 | * An entry with a NULL ID is assumed to be a wildcard. | |
30 | * If an entry has a device ID, it must match | |
31 | * If an entry has a connection ID, it must match | |
32 | * Then we take the most specific entry - with the following | |
659431fc | 33 | * order of precedence: dev+con > dev only > con only. |
409dc360 | 34 | */ |
e8bf8df9 | 35 | static struct clk_lookup *clk_find(const char *dev_id, const char *con_id) |
0318e693 | 36 | { |
e8bf8df9 | 37 | struct clk_lookup *p, *cl = NULL; |
0318e693 RK |
38 | int match, best = 0; |
39 | ||
40 | list_for_each_entry(p, &clocks, node) { | |
0318e693 | 41 | match = 0; |
409dc360 RK |
42 | if (p->dev_id) { |
43 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
44 | continue; | |
45 | match += 2; | |
46 | } | |
47 | if (p->con_id) { | |
48 | if (!con_id || strcmp(p->con_id, con_id)) | |
49 | continue; | |
50 | match += 1; | |
51 | } | |
0318e693 RK |
52 | |
53 | if (match > best) { | |
e8bf8df9 | 54 | cl = p; |
e4bf5bec | 55 | if (match != 3) |
56 | best = match; | |
57 | else | |
58 | break; | |
0318e693 RK |
59 | } |
60 | } | |
e8bf8df9 | 61 | return cl; |
0318e693 RK |
62 | } |
63 | ||
05fd8e73 | 64 | struct clk *clk_get_sys(const char *dev_id, const char *con_id) |
0318e693 | 65 | { |
e8bf8df9 | 66 | struct clk_lookup *cl; |
0318e693 RK |
67 | |
68 | mutex_lock(&clocks_mutex); | |
e8bf8df9 RK |
69 | cl = clk_find(dev_id, con_id); |
70 | if (cl && !__clk_get(cl->clk)) | |
71 | cl = NULL; | |
0318e693 RK |
72 | mutex_unlock(&clocks_mutex); |
73 | ||
e8bf8df9 | 74 | return cl ? cl->clk : ERR_PTR(-ENOENT); |
0318e693 | 75 | } |
05fd8e73 SH |
76 | EXPORT_SYMBOL(clk_get_sys); |
77 | ||
78 | struct clk *clk_get(struct device *dev, const char *con_id) | |
79 | { | |
80 | const char *dev_id = dev ? dev_name(dev) : NULL; | |
81 | ||
82 | return clk_get_sys(dev_id, con_id); | |
83 | } | |
0318e693 RK |
84 | EXPORT_SYMBOL(clk_get); |
85 | ||
86 | void clk_put(struct clk *clk) | |
87 | { | |
88 | __clk_put(clk); | |
89 | } | |
90 | EXPORT_SYMBOL(clk_put); | |
91 | ||
92 | void clkdev_add(struct clk_lookup *cl) | |
93 | { | |
94 | mutex_lock(&clocks_mutex); | |
95 | list_add_tail(&cl->node, &clocks); | |
96 | mutex_unlock(&clocks_mutex); | |
97 | } | |
98 | EXPORT_SYMBOL(clkdev_add); | |
99 | ||
0a0300dc RK |
100 | void __init clkdev_add_table(struct clk_lookup *cl, size_t num) |
101 | { | |
102 | mutex_lock(&clocks_mutex); | |
103 | while (num--) { | |
104 | list_add_tail(&cl->node, &clocks); | |
105 | cl++; | |
106 | } | |
107 | mutex_unlock(&clocks_mutex); | |
108 | } | |
109 | ||
0318e693 RK |
110 | #define MAX_DEV_ID 20 |
111 | #define MAX_CON_ID 16 | |
112 | ||
113 | struct clk_lookup_alloc { | |
114 | struct clk_lookup cl; | |
115 | char dev_id[MAX_DEV_ID]; | |
116 | char con_id[MAX_CON_ID]; | |
117 | }; | |
118 | ||
6d803ba7 JCPV |
119 | struct clk_lookup * __init_refok |
120 | clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...) | |
0318e693 RK |
121 | { |
122 | struct clk_lookup_alloc *cla; | |
123 | ||
6d803ba7 | 124 | cla = __clkdev_alloc(sizeof(*cla)); |
0318e693 RK |
125 | if (!cla) |
126 | return NULL; | |
127 | ||
128 | cla->cl.clk = clk; | |
129 | if (con_id) { | |
130 | strlcpy(cla->con_id, con_id, sizeof(cla->con_id)); | |
131 | cla->cl.con_id = cla->con_id; | |
132 | } | |
133 | ||
134 | if (dev_fmt) { | |
135 | va_list ap; | |
136 | ||
137 | va_start(ap, dev_fmt); | |
138 | vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap); | |
139 | cla->cl.dev_id = cla->dev_id; | |
140 | va_end(ap); | |
141 | } | |
142 | ||
143 | return &cla->cl; | |
144 | } | |
145 | EXPORT_SYMBOL(clkdev_alloc); | |
146 | ||
c0683039 TL |
147 | int clk_add_alias(const char *alias, const char *alias_dev_name, char *id, |
148 | struct device *dev) | |
149 | { | |
150 | struct clk *r = clk_get(dev, id); | |
151 | struct clk_lookup *l; | |
152 | ||
153 | if (IS_ERR(r)) | |
154 | return PTR_ERR(r); | |
155 | ||
156 | l = clkdev_alloc(r, alias, alias_dev_name); | |
157 | clk_put(r); | |
158 | if (!l) | |
159 | return -ENODEV; | |
160 | clkdev_add(l); | |
161 | return 0; | |
162 | } | |
163 | EXPORT_SYMBOL(clk_add_alias); | |
164 | ||
0318e693 RK |
165 | /* |
166 | * clkdev_drop - remove a clock dynamically allocated | |
167 | */ | |
168 | void clkdev_drop(struct clk_lookup *cl) | |
169 | { | |
170 | mutex_lock(&clocks_mutex); | |
171 | list_del(&cl->node); | |
172 | mutex_unlock(&clocks_mutex); | |
173 | kfree(cl); | |
174 | } | |
175 | EXPORT_SYMBOL(clkdev_drop); |