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-rw-r--r--arch/sh/kernel/clkdev.c162
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
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+++ b/arch/sh/kernel/clkdev.c
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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
26static LIST_HEAD(clocks);
27static 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 */
38static 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
67struct 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}
77EXPORT_SYMBOL(clk_get_sys);
78
79void 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}
85EXPORT_SYMBOL(clkdev_add);
86
87void __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
100struct clk_lookup_alloc {
101 struct clk_lookup cl;
102 char dev_id[MAX_DEV_ID];
103 char con_id[MAX_CON_ID];
104};
105
106struct 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}
132EXPORT_SYMBOL(clkdev_alloc);
133
134int 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}
150EXPORT_SYMBOL(clk_add_alias);
151
152/*
153 * clkdev_drop - remove a clock dynamically allocated
154 */
155void 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}
162EXPORT_SYMBOL(clkdev_drop);