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);
31 * Find the correct struct clk for the device and connection ID.
32 * We do slightly fuzzy matching here:
33 * An entry with a NULL ID is assumed to be a wildcard.
34 * If an entry has a device ID, it must match
35 * If an entry has a connection ID, it must match
36 * Then we take the most specific entry - with the following
37 * order of precedence: dev+con > dev only > con only.
39 static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
41 struct clk_lookup *p, *cl = NULL;
42 int match, best_found = 0, best_possible = 0;
49 lockdep_assert_held(&clocks_mutex);
51 list_for_each_entry(p, &clocks, node) {
54 if (!dev_id || strcmp(p->dev_id, dev_id))
59 if (!con_id || strcmp(p->con_id, con_id))
64 if (match > best_found) {
66 if (match != best_possible)
75 struct clk_hw *clk_find_hw(const char *dev_id, const char *con_id)
77 struct clk_lookup *cl;
78 struct clk_hw *hw = ERR_PTR(-ENOENT);
80 mutex_lock(&clocks_mutex);
81 cl = clk_find(dev_id, con_id);
84 mutex_unlock(&clocks_mutex);
89 static struct clk *__clk_get_sys(struct device *dev, const char *dev_id,
92 struct clk_hw *hw = clk_find_hw(dev_id, con_id);
94 return clk_hw_create_clk(dev, hw, dev_id, con_id);
97 struct clk *clk_get_sys(const char *dev_id, const char *con_id)
99 return __clk_get_sys(NULL, dev_id, con_id);
101 EXPORT_SYMBOL(clk_get_sys);
103 struct clk *clk_get(struct device *dev, const char *con_id)
105 const char *dev_id = dev ? dev_name(dev) : NULL;
108 if (dev && dev->of_node) {
109 hw = of_clk_get_hw(dev->of_node, 0, con_id);
110 if (!IS_ERR(hw) || PTR_ERR(hw) == -EPROBE_DEFER)
111 return clk_hw_create_clk(dev, hw, dev_id, con_id);
114 return __clk_get_sys(dev, dev_id, con_id);
116 EXPORT_SYMBOL(clk_get);
118 void clk_put(struct clk *clk)
122 EXPORT_SYMBOL(clk_put);
124 static void __clkdev_add(struct clk_lookup *cl)
126 mutex_lock(&clocks_mutex);
127 list_add_tail(&cl->node, &clocks);
128 mutex_unlock(&clocks_mutex);
131 void clkdev_add(struct clk_lookup *cl)
134 cl->clk_hw = __clk_get_hw(cl->clk);
137 EXPORT_SYMBOL(clkdev_add);
139 void clkdev_add_table(struct clk_lookup *cl, size_t num)
141 mutex_lock(&clocks_mutex);
143 cl->clk_hw = __clk_get_hw(cl->clk);
144 list_add_tail(&cl->node, &clocks);
147 mutex_unlock(&clocks_mutex);
150 #define MAX_DEV_ID 20
151 #define MAX_CON_ID 16
153 struct clk_lookup_alloc {
154 struct clk_lookup cl;
155 char dev_id[MAX_DEV_ID];
156 char con_id[MAX_CON_ID];
159 static struct clk_lookup * __ref
160 vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt,
163 struct clk_lookup_alloc *cla;
165 cla = kzalloc(sizeof(*cla), GFP_KERNEL);
171 strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
172 cla->cl.con_id = cla->con_id;
176 vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
177 cla->cl.dev_id = cla->dev_id;
183 static struct clk_lookup *
184 vclkdev_create(struct clk_hw *hw, const char *con_id, const char *dev_fmt,
187 struct clk_lookup *cl;
189 cl = vclkdev_alloc(hw, con_id, dev_fmt, ap);
196 struct clk_lookup * __ref
197 clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)
199 struct clk_lookup *cl;
202 va_start(ap, dev_fmt);
203 cl = vclkdev_alloc(__clk_get_hw(clk), con_id, dev_fmt, ap);
208 EXPORT_SYMBOL(clkdev_alloc);
211 clkdev_hw_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt, ...)
213 struct clk_lookup *cl;
216 va_start(ap, dev_fmt);
217 cl = vclkdev_alloc(hw, con_id, dev_fmt, ap);
222 EXPORT_SYMBOL(clkdev_hw_alloc);
225 * clkdev_create - allocate and add a clkdev lookup structure
226 * @clk: struct clk to associate with all clk_lookups
227 * @con_id: connection ID string on device
228 * @dev_fmt: format string describing device name
230 * Returns a clk_lookup structure, which can be later unregistered and
233 struct clk_lookup *clkdev_create(struct clk *clk, const char *con_id,
234 const char *dev_fmt, ...)
236 struct clk_lookup *cl;
239 va_start(ap, dev_fmt);
240 cl = vclkdev_create(__clk_get_hw(clk), con_id, dev_fmt, ap);
245 EXPORT_SYMBOL_GPL(clkdev_create);
248 * clkdev_hw_create - allocate and add a clkdev lookup structure
249 * @hw: struct clk_hw to associate with all clk_lookups
250 * @con_id: connection ID string on device
251 * @dev_fmt: format string describing device name
253 * Returns a clk_lookup structure, which can be later unregistered and
256 struct clk_lookup *clkdev_hw_create(struct clk_hw *hw, const char *con_id,
257 const char *dev_fmt, ...)
259 struct clk_lookup *cl;
262 va_start(ap, dev_fmt);
263 cl = vclkdev_create(hw, con_id, dev_fmt, ap);
268 EXPORT_SYMBOL_GPL(clkdev_hw_create);
270 int clk_add_alias(const char *alias, const char *alias_dev_name,
271 const char *con_id, struct device *dev)
273 struct clk *r = clk_get(dev, con_id);
274 struct clk_lookup *l;
279 l = clkdev_create(r, alias, alias_dev_name ? "%s" : NULL,
283 return l ? 0 : -ENODEV;
285 EXPORT_SYMBOL(clk_add_alias);
288 * clkdev_drop - remove a clock dynamically allocated
290 void clkdev_drop(struct clk_lookup *cl)
292 mutex_lock(&clocks_mutex);
294 mutex_unlock(&clocks_mutex);
297 EXPORT_SYMBOL(clkdev_drop);
299 static struct clk_lookup *__clk_register_clkdev(struct clk_hw *hw,
301 const char *dev_id, ...)
303 struct clk_lookup *cl;
306 va_start(ap, dev_id);
307 cl = vclkdev_create(hw, con_id, dev_id, ap);
313 static int do_clk_register_clkdev(struct clk_hw *hw,
314 struct clk_lookup **cl, const char *con_id, const char *dev_id)
319 * Since dev_id can be NULL, and NULL is handled specially, we must
320 * pass it as either a NULL format string, or with "%s".
323 *cl = __clk_register_clkdev(hw, con_id, "%s", dev_id);
325 *cl = __clk_register_clkdev(hw, con_id, NULL);
327 return *cl ? 0 : -ENOMEM;
331 * clk_register_clkdev - register one clock lookup for a struct clk
332 * @clk: struct clk to associate with all clk_lookups
333 * @con_id: connection ID string on device
334 * @dev_id: string describing device name
336 * con_id or dev_id may be NULL as a wildcard, just as in the rest of
339 * To make things easier for mass registration, we detect error clks
340 * from a previous clk_register() call, and return the error code for
341 * those. This is to permit this function to be called immediately
342 * after clk_register().
344 int clk_register_clkdev(struct clk *clk, const char *con_id,
347 struct clk_lookup *cl;
352 return do_clk_register_clkdev(__clk_get_hw(clk), &cl, con_id,
355 EXPORT_SYMBOL(clk_register_clkdev);
358 * clk_hw_register_clkdev - register one clock lookup for a struct clk_hw
359 * @hw: struct clk_hw to associate with all clk_lookups
360 * @con_id: connection ID string on device
361 * @dev_id: format string describing device name
363 * con_id or dev_id may be NULL as a wildcard, just as in the rest of
366 * To make things easier for mass registration, we detect error clk_hws
367 * from a previous clk_hw_register_*() call, and return the error code for
368 * those. This is to permit this function to be called immediately
369 * after clk_hw_register_*().
371 int clk_hw_register_clkdev(struct clk_hw *hw, const char *con_id,
374 struct clk_lookup *cl;
376 return do_clk_register_clkdev(hw, &cl, con_id, dev_id);
378 EXPORT_SYMBOL(clk_hw_register_clkdev);
380 static void devm_clkdev_release(struct device *dev, void *res)
382 clkdev_drop(*(struct clk_lookup **)res);
385 static int devm_clk_match_clkdev(struct device *dev, void *res, void *data)
387 struct clk_lookup **l = res;
393 * devm_clk_release_clkdev - Resource managed clkdev lookup release
394 * @dev: device this lookup is bound
395 * @con_id: connection ID string on device
396 * @dev_id: format string describing device name
398 * Drop the clkdev lookup created with devm_clk_hw_register_clkdev.
399 * Normally this function will not need to be called and the resource
400 * management code will ensure that the resource is freed.
402 void devm_clk_release_clkdev(struct device *dev, const char *con_id,
405 struct clk_lookup *cl;
408 mutex_lock(&clocks_mutex);
409 cl = clk_find(dev_id, con_id);
410 mutex_unlock(&clocks_mutex);
413 rval = devres_release(dev, devm_clkdev_release,
414 devm_clk_match_clkdev, cl);
417 EXPORT_SYMBOL(devm_clk_release_clkdev);
420 * devm_clk_hw_register_clkdev - managed clk lookup registration for clk_hw
421 * @dev: device this lookup is bound
422 * @hw: struct clk_hw to associate with all clk_lookups
423 * @con_id: connection ID string on device
424 * @dev_id: format string describing device name
426 * con_id or dev_id may be NULL as a wildcard, just as in the rest of
429 * To make things easier for mass registration, we detect error clk_hws
430 * from a previous clk_hw_register_*() call, and return the error code for
431 * those. This is to permit this function to be called immediately
432 * after clk_hw_register_*().
434 int devm_clk_hw_register_clkdev(struct device *dev, struct clk_hw *hw,
435 const char *con_id, const char *dev_id)
438 struct clk_lookup **cl;
440 cl = devres_alloc(devm_clkdev_release, sizeof(*cl), GFP_KERNEL);
442 rval = do_clk_register_clkdev(hw, cl, con_id, dev_id);
450 EXPORT_SYMBOL(devm_clk_hw_register_clkdev);