4 * Copyright (C) 2008 Russell King.
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.
10 * Helper for the clk API to assist looking up a struct clk.
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 #include <linux/clk.h>
21 #include <linux/clkdev.h>
23 static LIST_HEAD(clocks
);
24 static DEFINE_MUTEX(clocks_mutex
);
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
33 * order of precedence: dev+con > dev only > con only.
35 static struct clk_lookup
*clk_find(const char *dev_id
, const char *con_id
)
37 struct clk_lookup
*p
, *cl
= NULL
;
38 int match
, best_found
= 0, best_possible
= 0;
45 list_for_each_entry(p
, &clocks
, node
) {
48 if (!dev_id
|| strcmp(p
->dev_id
, dev_id
))
53 if (!con_id
|| strcmp(p
->con_id
, con_id
))
58 if (match
> best_found
) {
60 if (match
!= best_possible
)
69 struct clk
*clk_get_sys(const char *dev_id
, const char *con_id
)
71 struct clk_lookup
*cl
;
73 mutex_lock(&clocks_mutex
);
74 cl
= clk_find(dev_id
, con_id
);
75 if (cl
&& !__clk_get(cl
->clk
))
77 mutex_unlock(&clocks_mutex
);
79 return cl
? cl
->clk
: ERR_PTR(-ENOENT
);
81 EXPORT_SYMBOL(clk_get_sys
);
83 struct clk
*clk_get(struct device
*dev
, const char *con_id
)
85 const char *dev_id
= dev
? dev_name(dev
) : NULL
;
87 return clk_get_sys(dev_id
, con_id
);
89 EXPORT_SYMBOL(clk_get
);
91 void clk_put(struct clk
*clk
)
95 EXPORT_SYMBOL(clk_put
);
97 static void devm_clk_release(struct device
*dev
, void *res
)
99 clk_put(*(struct clk
**)res
);
102 struct clk
*devm_clk_get(struct device
*dev
, const char *id
)
104 struct clk
**ptr
, *clk
;
106 ptr
= devres_alloc(devm_clk_release
, sizeof(*ptr
), GFP_KERNEL
);
108 return ERR_PTR(-ENOMEM
);
110 clk
= clk_get(dev
, id
);
113 devres_add(dev
, ptr
);
120 EXPORT_SYMBOL(devm_clk_get
);
122 static int devm_clk_match(struct device
*dev
, void *res
, void *data
)
124 struct clk
**c
= res
;
132 void devm_clk_put(struct device
*dev
, struct clk
*clk
)
136 ret
= devres_destroy(dev
, devm_clk_release
, devm_clk_match
, clk
);
140 EXPORT_SYMBOL(devm_clk_put
);
142 void clkdev_add(struct clk_lookup
*cl
)
144 mutex_lock(&clocks_mutex
);
145 list_add_tail(&cl
->node
, &clocks
);
146 mutex_unlock(&clocks_mutex
);
148 EXPORT_SYMBOL(clkdev_add
);
150 void __init
clkdev_add_table(struct clk_lookup
*cl
, size_t num
)
152 mutex_lock(&clocks_mutex
);
154 list_add_tail(&cl
->node
, &clocks
);
157 mutex_unlock(&clocks_mutex
);
160 #define MAX_DEV_ID 20
161 #define MAX_CON_ID 16
163 struct clk_lookup_alloc
{
164 struct clk_lookup cl
;
165 char dev_id
[MAX_DEV_ID
];
166 char con_id
[MAX_CON_ID
];
169 static struct clk_lookup
* __init_refok
170 vclkdev_alloc(struct clk
*clk
, const char *con_id
, const char *dev_fmt
,
173 struct clk_lookup_alloc
*cla
;
175 cla
= __clkdev_alloc(sizeof(*cla
));
181 strlcpy(cla
->con_id
, con_id
, sizeof(cla
->con_id
));
182 cla
->cl
.con_id
= cla
->con_id
;
186 vscnprintf(cla
->dev_id
, sizeof(cla
->dev_id
), dev_fmt
, ap
);
187 cla
->cl
.dev_id
= cla
->dev_id
;
193 struct clk_lookup
* __init_refok
194 clkdev_alloc(struct clk
*clk
, const char *con_id
, const char *dev_fmt
, ...)
196 struct clk_lookup
*cl
;
199 va_start(ap
, dev_fmt
);
200 cl
= vclkdev_alloc(clk
, con_id
, dev_fmt
, ap
);
205 EXPORT_SYMBOL(clkdev_alloc
);
207 int clk_add_alias(const char *alias
, const char *alias_dev_name
, char *id
,
210 struct clk
*r
= clk_get(dev
, id
);
211 struct clk_lookup
*l
;
216 l
= clkdev_alloc(r
, alias
, alias_dev_name
);
223 EXPORT_SYMBOL(clk_add_alias
);
226 * clkdev_drop - remove a clock dynamically allocated
228 void clkdev_drop(struct clk_lookup
*cl
)
230 mutex_lock(&clocks_mutex
);
232 mutex_unlock(&clocks_mutex
);
235 EXPORT_SYMBOL(clkdev_drop
);
238 * clk_register_clkdev - register one clock lookup for a struct clk
239 * @clk: struct clk to associate with all clk_lookups
240 * @con_id: connection ID string on device
241 * @dev_id: format string describing device name
243 * con_id or dev_id may be NULL as a wildcard, just as in the rest of
246 * To make things easier for mass registration, we detect error clks
247 * from a previous clk_register() call, and return the error code for
248 * those. This is to permit this function to be called immediately
249 * after clk_register().
251 int clk_register_clkdev(struct clk
*clk
, const char *con_id
,
252 const char *dev_fmt
, ...)
254 struct clk_lookup
*cl
;
260 va_start(ap
, dev_fmt
);
261 cl
= vclkdev_alloc(clk
, con_id
, dev_fmt
, ap
);
273 * clk_register_clkdevs - register a set of clk_lookup for a struct clk
274 * @clk: struct clk to associate with all clk_lookups
275 * @cl: array of clk_lookup structures with con_id and dev_id pre-initialized
276 * @num: number of clk_lookup structures to register
278 * To make things easier for mass registration, we detect error clks
279 * from a previous clk_register() call, and return the error code for
280 * those. This is to permit this function to be called immediately
281 * after clk_register().
283 int clk_register_clkdevs(struct clk
*clk
, struct clk_lookup
*cl
, size_t num
)
290 for (i
= 0; i
< num
; i
++, cl
++) {
297 EXPORT_SYMBOL(clk_register_clkdevs
);
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