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51a5006a PM |
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> | |
2e733b3f PM |
23 | #include <linux/slab.h> |
24 | #include <linux/bootmem.h> | |
25 | #include <linux/mm.h> | |
51a5006a PM |
26 | #include <asm/clock.h> |
27 | #include <asm/clkdev.h> | |
28 | ||
29 | static LIST_HEAD(clocks); | |
30 | static DEFINE_MUTEX(clocks_mutex); | |
31 | ||
32 | /* | |
33 | * Find the correct struct clk for the device and connection ID. | |
34 | * We do slightly fuzzy matching here: | |
35 | * An entry with a NULL ID is assumed to be a wildcard. | |
36 | * If an entry has a device ID, it must match | |
37 | * If an entry has a connection ID, it must match | |
38 | * Then we take the most specific entry - with the following | |
bd06cac8 | 39 | * order of precedence: dev+con > dev only > con only. |
51a5006a PM |
40 | */ |
41 | static struct clk *clk_find(const char *dev_id, const char *con_id) | |
42 | { | |
43 | struct clk_lookup *p; | |
44 | struct clk *clk = NULL; | |
45 | int match, best = 0; | |
46 | ||
47 | list_for_each_entry(p, &clocks, node) { | |
48 | match = 0; | |
49 | if (p->dev_id) { | |
50 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
51 | continue; | |
52 | match += 2; | |
53 | } | |
54 | if (p->con_id) { | |
55 | if (!con_id || strcmp(p->con_id, con_id)) | |
56 | continue; | |
57 | match += 1; | |
58 | } | |
59 | if (match == 0) | |
60 | continue; | |
61 | ||
62 | if (match > best) { | |
63 | clk = p->clk; | |
64 | best = match; | |
65 | } | |
66 | } | |
67 | return clk; | |
68 | } | |
69 | ||
70 | struct clk *clk_get_sys(const char *dev_id, const char *con_id) | |
71 | { | |
72 | struct clk *clk; | |
73 | ||
74 | mutex_lock(&clocks_mutex); | |
75 | clk = clk_find(dev_id, con_id); | |
76 | mutex_unlock(&clocks_mutex); | |
77 | ||
78 | return clk ? clk : ERR_PTR(-ENOENT); | |
79 | } | |
80 | EXPORT_SYMBOL(clk_get_sys); | |
81 | ||
82 | void clkdev_add(struct clk_lookup *cl) | |
83 | { | |
84 | mutex_lock(&clocks_mutex); | |
85 | list_add_tail(&cl->node, &clocks); | |
86 | mutex_unlock(&clocks_mutex); | |
87 | } | |
88 | EXPORT_SYMBOL(clkdev_add); | |
89 | ||
90 | void __init clkdev_add_table(struct clk_lookup *cl, size_t num) | |
91 | { | |
92 | mutex_lock(&clocks_mutex); | |
93 | while (num--) { | |
94 | list_add_tail(&cl->node, &clocks); | |
95 | cl++; | |
96 | } | |
97 | mutex_unlock(&clocks_mutex); | |
98 | } | |
99 | ||
100 | #define MAX_DEV_ID 20 | |
101 | #define MAX_CON_ID 16 | |
102 | ||
103 | struct clk_lookup_alloc { | |
104 | struct clk_lookup cl; | |
105 | char dev_id[MAX_DEV_ID]; | |
106 | char con_id[MAX_CON_ID]; | |
107 | }; | |
108 | ||
2e733b3f PM |
109 | struct clk_lookup * __init_refok |
110 | clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...) | |
51a5006a PM |
111 | { |
112 | struct clk_lookup_alloc *cla; | |
113 | ||
2e733b3f PM |
114 | if (!slab_is_available()) |
115 | cla = alloc_bootmem_low_pages(sizeof(*cla)); | |
116 | else | |
117 | cla = kzalloc(sizeof(*cla), GFP_KERNEL); | |
118 | ||
51a5006a PM |
119 | if (!cla) |
120 | return NULL; | |
121 | ||
122 | cla->cl.clk = clk; | |
123 | if (con_id) { | |
124 | strlcpy(cla->con_id, con_id, sizeof(cla->con_id)); | |
125 | cla->cl.con_id = cla->con_id; | |
126 | } | |
127 | ||
128 | if (dev_fmt) { | |
129 | va_list ap; | |
130 | ||
131 | va_start(ap, dev_fmt); | |
132 | vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap); | |
133 | cla->cl.dev_id = cla->dev_id; | |
134 | va_end(ap); | |
135 | } | |
136 | ||
137 | return &cla->cl; | |
138 | } | |
139 | EXPORT_SYMBOL(clkdev_alloc); | |
140 | ||
141 | int clk_add_alias(const char *alias, const char *alias_dev_name, char *id, | |
142 | struct device *dev) | |
143 | { | |
144 | struct clk *r = clk_get(dev, id); | |
145 | struct clk_lookup *l; | |
146 | ||
147 | if (IS_ERR(r)) | |
148 | return PTR_ERR(r); | |
149 | ||
150 | l = clkdev_alloc(r, alias, alias_dev_name); | |
151 | clk_put(r); | |
152 | if (!l) | |
153 | return -ENODEV; | |
154 | clkdev_add(l); | |
155 | return 0; | |
156 | } | |
157 | EXPORT_SYMBOL(clk_add_alias); | |
158 | ||
159 | /* | |
160 | * clkdev_drop - remove a clock dynamically allocated | |
161 | */ | |
162 | void clkdev_drop(struct clk_lookup *cl) | |
163 | { | |
4c62c595 GL |
164 | struct clk_lookup_alloc *cla = container_of(cl, struct clk_lookup_alloc, cl); |
165 | ||
51a5006a PM |
166 | mutex_lock(&clocks_mutex); |
167 | list_del(&cl->node); | |
168 | mutex_unlock(&clocks_mutex); | |
4c62c595 | 169 | kfree(cla); |
51a5006a PM |
170 | } |
171 | EXPORT_SYMBOL(clkdev_drop); |