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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - drivers/clk/clkdev.c
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>
22 #include <linux/clk-provider.h>
27 static LIST_HEAD(clocks
);
28 static DEFINE_MUTEX(clocks_mutex
);
30 #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
31 static struct clk
*__of_clk_get(struct device_node
*np
, int index
,
32 const char *dev_id
, const char *con_id
)
34 struct of_phandle_args clkspec
;
39 return ERR_PTR(-EINVAL
);
41 rc
= of_parse_phandle_with_args(np
, "clocks", "#clock-cells", index
,
46 clk
= __of_clk_get_from_provider(&clkspec
, dev_id
, con_id
);
47 of_node_put(clkspec
.np
);
52 struct clk
*of_clk_get(struct device_node
*np
, int index
)
54 return __of_clk_get(np
, index
, np
->full_name
, NULL
);
56 EXPORT_SYMBOL(of_clk_get
);
58 static struct clk
*__of_clk_get_by_name(struct device_node
*np
,
62 struct clk
*clk
= ERR_PTR(-ENOENT
);
64 /* Walk up the tree of devices looking for a clock that matches */
69 * For named clocks, first look up the name in the
70 * "clock-names" property. If it cannot be found, then
71 * index will be an error code, and of_clk_get() will fail.
74 index
= of_property_match_string(np
, "clock-names", name
);
75 clk
= __of_clk_get(np
, index
, dev_id
, name
);
78 } else if (name
&& index
>= 0) {
79 if (PTR_ERR(clk
) != -EPROBE_DEFER
)
80 pr_err("ERROR: could not get clock %s:%s(%i)\n",
81 np
->full_name
, name
? name
: "", index
);
86 * No matching clock found on this node. If the parent node
87 * has a "clock-ranges" property, then we can try one of its
91 if (np
&& !of_get_property(np
, "clock-ranges", NULL
))
99 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
100 * @np: pointer to clock consumer node
101 * @name: name of consumer's clock input, or NULL for the first clock reference
103 * This function parses the clocks and clock-names properties,
104 * and uses them to look up the struct clk from the registered list of clock
107 struct clk
*of_clk_get_by_name(struct device_node
*np
, const char *name
)
110 return ERR_PTR(-ENOENT
);
112 return __of_clk_get_by_name(np
, np
->full_name
, name
);
114 EXPORT_SYMBOL(of_clk_get_by_name
);
116 #else /* defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) */
118 static struct clk
*__of_clk_get_by_name(struct device_node
*np
,
122 return ERR_PTR(-ENOENT
);
127 * Find the correct struct clk for the device and connection ID.
128 * We do slightly fuzzy matching here:
129 * An entry with a NULL ID is assumed to be a wildcard.
130 * If an entry has a device ID, it must match
131 * If an entry has a connection ID, it must match
132 * Then we take the most specific entry - with the following
133 * order of precedence: dev+con > dev only > con only.
135 static struct clk_lookup
*clk_find(const char *dev_id
, const char *con_id
)
137 struct clk_lookup
*p
, *cl
= NULL
;
138 int match
, best_found
= 0, best_possible
= 0;
145 list_for_each_entry(p
, &clocks
, node
) {
148 if (!dev_id
|| strcmp(p
->dev_id
, dev_id
))
153 if (!con_id
|| strcmp(p
->con_id
, con_id
))
158 if (match
> best_found
) {
160 if (match
!= best_possible
)
169 struct clk
*clk_get_sys(const char *dev_id
, const char *con_id
)
171 struct clk_lookup
*cl
;
172 struct clk
*clk
= NULL
;
174 mutex_lock(&clocks_mutex
);
176 cl
= clk_find(dev_id
, con_id
);
180 clk
= __clk_create_clk(cl
->clk_hw
, dev_id
, con_id
);
184 if (!__clk_get(clk
)) {
191 mutex_unlock(&clocks_mutex
);
193 return cl
? clk
: ERR_PTR(-ENOENT
);
195 EXPORT_SYMBOL(clk_get_sys
);
197 struct clk
*clk_get(struct device
*dev
, const char *con_id
)
199 const char *dev_id
= dev
? dev_name(dev
) : NULL
;
203 clk
= __of_clk_get_by_name(dev
->of_node
, dev_id
, con_id
);
204 if (!IS_ERR(clk
) || PTR_ERR(clk
) == -EPROBE_DEFER
)
208 return clk_get_sys(dev_id
, con_id
);
210 EXPORT_SYMBOL(clk_get
);
212 void clk_put(struct clk
*clk
)
216 EXPORT_SYMBOL(clk_put
);
218 static void __clkdev_add(struct clk_lookup
*cl
)
220 mutex_lock(&clocks_mutex
);
221 list_add_tail(&cl
->node
, &clocks
);
222 mutex_unlock(&clocks_mutex
);
225 void clkdev_add(struct clk_lookup
*cl
)
228 cl
->clk_hw
= __clk_get_hw(cl
->clk
);
231 EXPORT_SYMBOL(clkdev_add
);
233 void clkdev_add_table(struct clk_lookup
*cl
, size_t num
)
235 mutex_lock(&clocks_mutex
);
237 cl
->clk_hw
= __clk_get_hw(cl
->clk
);
238 list_add_tail(&cl
->node
, &clocks
);
241 mutex_unlock(&clocks_mutex
);
244 #define MAX_DEV_ID 20
245 #define MAX_CON_ID 16
247 struct clk_lookup_alloc
{
248 struct clk_lookup cl
;
249 char dev_id
[MAX_DEV_ID
];
250 char con_id
[MAX_CON_ID
];
253 static struct clk_lookup
* __init_refok
254 vclkdev_alloc(struct clk_hw
*hw
, const char *con_id
, const char *dev_fmt
,
257 struct clk_lookup_alloc
*cla
;
259 cla
= __clkdev_alloc(sizeof(*cla
));
265 strlcpy(cla
->con_id
, con_id
, sizeof(cla
->con_id
));
266 cla
->cl
.con_id
= cla
->con_id
;
270 vscnprintf(cla
->dev_id
, sizeof(cla
->dev_id
), dev_fmt
, ap
);
271 cla
->cl
.dev_id
= cla
->dev_id
;
277 static struct clk_lookup
*
278 vclkdev_create(struct clk_hw
*hw
, const char *con_id
, const char *dev_fmt
,
281 struct clk_lookup
*cl
;
283 cl
= vclkdev_alloc(hw
, con_id
, dev_fmt
, ap
);
290 struct clk_lookup
* __init_refok
291 clkdev_alloc(struct clk
*clk
, const char *con_id
, const char *dev_fmt
, ...)
293 struct clk_lookup
*cl
;
296 va_start(ap
, dev_fmt
);
297 cl
= vclkdev_alloc(__clk_get_hw(clk
), con_id
, dev_fmt
, ap
);
302 EXPORT_SYMBOL(clkdev_alloc
);
305 * clkdev_create - allocate and add a clkdev lookup structure
306 * @clk: struct clk to associate with all clk_lookups
307 * @con_id: connection ID string on device
308 * @dev_fmt: format string describing device name
310 * Returns a clk_lookup structure, which can be later unregistered and
313 struct clk_lookup
*clkdev_create(struct clk
*clk
, const char *con_id
,
314 const char *dev_fmt
, ...)
316 struct clk_lookup
*cl
;
319 va_start(ap
, dev_fmt
);
320 cl
= vclkdev_create(__clk_get_hw(clk
), con_id
, dev_fmt
, ap
);
325 EXPORT_SYMBOL_GPL(clkdev_create
);
327 int clk_add_alias(const char *alias
, const char *alias_dev_name
,
328 const char *con_id
, struct device
*dev
)
330 struct clk
*r
= clk_get(dev
, con_id
);
331 struct clk_lookup
*l
;
336 l
= clkdev_create(r
, alias
, "%s", alias_dev_name
);
339 return l
? 0 : -ENODEV
;
341 EXPORT_SYMBOL(clk_add_alias
);
344 * clkdev_drop - remove a clock dynamically allocated
346 void clkdev_drop(struct clk_lookup
*cl
)
348 mutex_lock(&clocks_mutex
);
350 mutex_unlock(&clocks_mutex
);
353 EXPORT_SYMBOL(clkdev_drop
);
356 * clk_register_clkdev - register one clock lookup for a struct clk
357 * @clk: struct clk to associate with all clk_lookups
358 * @con_id: connection ID string on device
359 * @dev_id: format string describing device name
361 * con_id or dev_id may be NULL as a wildcard, just as in the rest of
364 * To make things easier for mass registration, we detect error clks
365 * from a previous clk_register() call, and return the error code for
366 * those. This is to permit this function to be called immediately
367 * after clk_register().
369 int clk_register_clkdev(struct clk
*clk
, const char *con_id
,
370 const char *dev_fmt
, ...)
372 struct clk_lookup
*cl
;
378 va_start(ap
, dev_fmt
);
379 cl
= vclkdev_create(__clk_get_hw(clk
), con_id
, dev_fmt
, ap
);
382 return cl
? 0 : -ENOMEM
;
384 EXPORT_SYMBOL(clk_register_clkdev
);
387 * clk_register_clkdevs - register a set of clk_lookup for a struct clk
388 * @clk: struct clk to associate with all clk_lookups
389 * @cl: array of clk_lookup structures with con_id and dev_id pre-initialized
390 * @num: number of clk_lookup structures to register
392 * To make things easier for mass registration, we detect error clks
393 * from a previous clk_register() call, and return the error code for
394 * those. This is to permit this function to be called immediately
395 * after clk_register().
397 int clk_register_clkdevs(struct clk
*clk
, struct clk_lookup
*cl
, size_t num
)
404 for (i
= 0; i
< num
; i
++, cl
++) {
405 cl
->clk_hw
= __clk_get_hw(clk
);
411 EXPORT_SYMBOL(clk_register_clkdevs
);