Commit | Line | Data |
---|---|---|
0318e693 | 1 | /* |
6d803ba7 | 2 | * drivers/clk/clkdev.c |
0318e693 RK |
3 | * |
4 | * Copyright (C) 2008 Russell King. | |
5 | * | |
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. | |
9 | * | |
10 | * Helper for the clk API to assist looking up a struct clk. | |
11 | */ | |
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> | |
c0c60c4b | 20 | #include <linux/clk.h> |
6d803ba7 | 21 | #include <linux/clkdev.h> |
766e6a4e | 22 | #include <linux/of.h> |
0318e693 RK |
23 | |
24 | static LIST_HEAD(clocks); | |
25 | static DEFINE_MUTEX(clocks_mutex); | |
26 | ||
137f8a72 | 27 | #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) |
766e6a4e GL |
28 | struct clk *of_clk_get(struct device_node *np, int index) |
29 | { | |
30 | struct of_phandle_args clkspec; | |
31 | struct clk *clk; | |
32 | int rc; | |
33 | ||
34 | if (index < 0) | |
35 | return ERR_PTR(-EINVAL); | |
36 | ||
37 | rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, | |
38 | &clkspec); | |
39 | if (rc) | |
40 | return ERR_PTR(rc); | |
41 | ||
42 | clk = of_clk_get_from_provider(&clkspec); | |
43 | of_node_put(clkspec.np); | |
44 | return clk; | |
45 | } | |
46 | EXPORT_SYMBOL(of_clk_get); | |
47 | ||
48 | /** | |
49 | * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node | |
50 | * @np: pointer to clock consumer node | |
51 | * @name: name of consumer's clock input, or NULL for the first clock reference | |
52 | * | |
53 | * This function parses the clocks and clock-names properties, | |
54 | * and uses them to look up the struct clk from the registered list of clock | |
55 | * providers. | |
56 | */ | |
57 | struct clk *of_clk_get_by_name(struct device_node *np, const char *name) | |
58 | { | |
59 | struct clk *clk = ERR_PTR(-ENOENT); | |
60 | ||
61 | /* Walk up the tree of devices looking for a clock that matches */ | |
62 | while (np) { | |
63 | int index = 0; | |
64 | ||
65 | /* | |
66 | * For named clocks, first look up the name in the | |
67 | * "clock-names" property. If it cannot be found, then | |
68 | * index will be an error code, and of_clk_get() will fail. | |
69 | */ | |
70 | if (name) | |
71 | index = of_property_match_string(np, "clock-names", name); | |
72 | clk = of_clk_get(np, index); | |
73 | if (!IS_ERR(clk)) | |
74 | break; | |
75 | else if (name && index >= 0) { | |
76 | pr_err("ERROR: could not get clock %s:%s(%i)\n", | |
77 | np->full_name, name ? name : "", index); | |
78 | return clk; | |
79 | } | |
80 | ||
81 | /* | |
82 | * No matching clock found on this node. If the parent node | |
83 | * has a "clock-ranges" property, then we can try one of its | |
84 | * clocks. | |
85 | */ | |
86 | np = np->parent; | |
87 | if (np && !of_get_property(np, "clock-ranges", NULL)) | |
88 | break; | |
89 | } | |
90 | ||
91 | return clk; | |
92 | } | |
93 | EXPORT_SYMBOL(of_clk_get_by_name); | |
94 | #endif | |
95 | ||
409dc360 RK |
96 | /* |
97 | * Find the correct struct clk for the device and connection ID. | |
98 | * We do slightly fuzzy matching here: | |
99 | * An entry with a NULL ID is assumed to be a wildcard. | |
100 | * If an entry has a device ID, it must match | |
101 | * If an entry has a connection ID, it must match | |
102 | * Then we take the most specific entry - with the following | |
659431fc | 103 | * order of precedence: dev+con > dev only > con only. |
409dc360 | 104 | */ |
e8bf8df9 | 105 | static struct clk_lookup *clk_find(const char *dev_id, const char *con_id) |
0318e693 | 106 | { |
e8bf8df9 | 107 | struct clk_lookup *p, *cl = NULL; |
67b50871 VK |
108 | int match, best_found = 0, best_possible = 0; |
109 | ||
110 | if (dev_id) | |
111 | best_possible += 2; | |
112 | if (con_id) | |
113 | best_possible += 1; | |
0318e693 RK |
114 | |
115 | list_for_each_entry(p, &clocks, node) { | |
0318e693 | 116 | match = 0; |
409dc360 RK |
117 | if (p->dev_id) { |
118 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
119 | continue; | |
120 | match += 2; | |
121 | } | |
122 | if (p->con_id) { | |
123 | if (!con_id || strcmp(p->con_id, con_id)) | |
124 | continue; | |
125 | match += 1; | |
126 | } | |
0318e693 | 127 | |
67b50871 | 128 | if (match > best_found) { |
e8bf8df9 | 129 | cl = p; |
67b50871 VK |
130 | if (match != best_possible) |
131 | best_found = match; | |
e4bf5bec | 132 | else |
133 | break; | |
0318e693 RK |
134 | } |
135 | } | |
e8bf8df9 | 136 | return cl; |
0318e693 RK |
137 | } |
138 | ||
05fd8e73 | 139 | struct clk *clk_get_sys(const char *dev_id, const char *con_id) |
0318e693 | 140 | { |
e8bf8df9 | 141 | struct clk_lookup *cl; |
0318e693 RK |
142 | |
143 | mutex_lock(&clocks_mutex); | |
e8bf8df9 RK |
144 | cl = clk_find(dev_id, con_id); |
145 | if (cl && !__clk_get(cl->clk)) | |
146 | cl = NULL; | |
0318e693 RK |
147 | mutex_unlock(&clocks_mutex); |
148 | ||
e8bf8df9 | 149 | return cl ? cl->clk : ERR_PTR(-ENOENT); |
0318e693 | 150 | } |
05fd8e73 SH |
151 | EXPORT_SYMBOL(clk_get_sys); |
152 | ||
153 | struct clk *clk_get(struct device *dev, const char *con_id) | |
154 | { | |
155 | const char *dev_id = dev ? dev_name(dev) : NULL; | |
766e6a4e GL |
156 | struct clk *clk; |
157 | ||
158 | if (dev) { | |
159 | clk = of_clk_get_by_name(dev->of_node, con_id); | |
9f1612d3 | 160 | if (!IS_ERR(clk) && __clk_get(clk)) |
766e6a4e GL |
161 | return clk; |
162 | } | |
05fd8e73 SH |
163 | |
164 | return clk_get_sys(dev_id, con_id); | |
165 | } | |
0318e693 RK |
166 | EXPORT_SYMBOL(clk_get); |
167 | ||
168 | void clk_put(struct clk *clk) | |
169 | { | |
170 | __clk_put(clk); | |
171 | } | |
172 | EXPORT_SYMBOL(clk_put); | |
173 | ||
a8a97db9 MB |
174 | static void devm_clk_release(struct device *dev, void *res) |
175 | { | |
176 | clk_put(*(struct clk **)res); | |
177 | } | |
178 | ||
179 | struct clk *devm_clk_get(struct device *dev, const char *id) | |
180 | { | |
181 | struct clk **ptr, *clk; | |
182 | ||
183 | ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL); | |
184 | if (!ptr) | |
185 | return ERR_PTR(-ENOMEM); | |
186 | ||
187 | clk = clk_get(dev, id); | |
188 | if (!IS_ERR(clk)) { | |
189 | *ptr = clk; | |
190 | devres_add(dev, ptr); | |
191 | } else { | |
192 | devres_free(ptr); | |
193 | } | |
194 | ||
195 | return clk; | |
196 | } | |
197 | EXPORT_SYMBOL(devm_clk_get); | |
198 | ||
199 | static int devm_clk_match(struct device *dev, void *res, void *data) | |
200 | { | |
201 | struct clk **c = res; | |
202 | if (!c || !*c) { | |
203 | WARN_ON(!c || !*c); | |
204 | return 0; | |
205 | } | |
206 | return *c == data; | |
207 | } | |
208 | ||
209 | void devm_clk_put(struct device *dev, struct clk *clk) | |
210 | { | |
211 | int ret; | |
212 | ||
213 | ret = devres_destroy(dev, devm_clk_release, devm_clk_match, clk); | |
214 | ||
215 | WARN_ON(ret); | |
216 | } | |
217 | EXPORT_SYMBOL(devm_clk_put); | |
218 | ||
0318e693 RK |
219 | void clkdev_add(struct clk_lookup *cl) |
220 | { | |
221 | mutex_lock(&clocks_mutex); | |
222 | list_add_tail(&cl->node, &clocks); | |
223 | mutex_unlock(&clocks_mutex); | |
224 | } | |
225 | EXPORT_SYMBOL(clkdev_add); | |
226 | ||
0a0300dc RK |
227 | void __init clkdev_add_table(struct clk_lookup *cl, size_t num) |
228 | { | |
229 | mutex_lock(&clocks_mutex); | |
230 | while (num--) { | |
231 | list_add_tail(&cl->node, &clocks); | |
232 | cl++; | |
233 | } | |
234 | mutex_unlock(&clocks_mutex); | |
235 | } | |
236 | ||
0318e693 RK |
237 | #define MAX_DEV_ID 20 |
238 | #define MAX_CON_ID 16 | |
239 | ||
240 | struct clk_lookup_alloc { | |
241 | struct clk_lookup cl; | |
242 | char dev_id[MAX_DEV_ID]; | |
243 | char con_id[MAX_CON_ID]; | |
244 | }; | |
245 | ||
e9d7f406 RK |
246 | static struct clk_lookup * __init_refok |
247 | vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, | |
248 | va_list ap) | |
0318e693 RK |
249 | { |
250 | struct clk_lookup_alloc *cla; | |
251 | ||
6d803ba7 | 252 | cla = __clkdev_alloc(sizeof(*cla)); |
0318e693 RK |
253 | if (!cla) |
254 | return NULL; | |
255 | ||
256 | cla->cl.clk = clk; | |
257 | if (con_id) { | |
258 | strlcpy(cla->con_id, con_id, sizeof(cla->con_id)); | |
259 | cla->cl.con_id = cla->con_id; | |
260 | } | |
261 | ||
262 | if (dev_fmt) { | |
0318e693 RK |
263 | vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap); |
264 | cla->cl.dev_id = cla->dev_id; | |
0318e693 RK |
265 | } |
266 | ||
267 | return &cla->cl; | |
268 | } | |
e9d7f406 RK |
269 | |
270 | struct clk_lookup * __init_refok | |
271 | clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...) | |
272 | { | |
273 | struct clk_lookup *cl; | |
274 | va_list ap; | |
275 | ||
276 | va_start(ap, dev_fmt); | |
277 | cl = vclkdev_alloc(clk, con_id, dev_fmt, ap); | |
278 | va_end(ap); | |
279 | ||
280 | return cl; | |
281 | } | |
0318e693 RK |
282 | EXPORT_SYMBOL(clkdev_alloc); |
283 | ||
c0683039 TL |
284 | int clk_add_alias(const char *alias, const char *alias_dev_name, char *id, |
285 | struct device *dev) | |
286 | { | |
287 | struct clk *r = clk_get(dev, id); | |
288 | struct clk_lookup *l; | |
289 | ||
290 | if (IS_ERR(r)) | |
291 | return PTR_ERR(r); | |
292 | ||
293 | l = clkdev_alloc(r, alias, alias_dev_name); | |
294 | clk_put(r); | |
295 | if (!l) | |
296 | return -ENODEV; | |
297 | clkdev_add(l); | |
298 | return 0; | |
299 | } | |
300 | EXPORT_SYMBOL(clk_add_alias); | |
301 | ||
0318e693 RK |
302 | /* |
303 | * clkdev_drop - remove a clock dynamically allocated | |
304 | */ | |
305 | void clkdev_drop(struct clk_lookup *cl) | |
306 | { | |
307 | mutex_lock(&clocks_mutex); | |
308 | list_del(&cl->node); | |
309 | mutex_unlock(&clocks_mutex); | |
310 | kfree(cl); | |
311 | } | |
312 | EXPORT_SYMBOL(clkdev_drop); | |
e9d7f406 RK |
313 | |
314 | /** | |
315 | * clk_register_clkdev - register one clock lookup for a struct clk | |
316 | * @clk: struct clk to associate with all clk_lookups | |
317 | * @con_id: connection ID string on device | |
318 | * @dev_id: format string describing device name | |
319 | * | |
320 | * con_id or dev_id may be NULL as a wildcard, just as in the rest of | |
321 | * clkdev. | |
322 | * | |
323 | * To make things easier for mass registration, we detect error clks | |
324 | * from a previous clk_register() call, and return the error code for | |
325 | * those. This is to permit this function to be called immediately | |
326 | * after clk_register(). | |
327 | */ | |
328 | int clk_register_clkdev(struct clk *clk, const char *con_id, | |
329 | const char *dev_fmt, ...) | |
330 | { | |
331 | struct clk_lookup *cl; | |
332 | va_list ap; | |
333 | ||
334 | if (IS_ERR(clk)) | |
335 | return PTR_ERR(clk); | |
336 | ||
337 | va_start(ap, dev_fmt); | |
338 | cl = vclkdev_alloc(clk, con_id, dev_fmt, ap); | |
339 | va_end(ap); | |
340 | ||
341 | if (!cl) | |
342 | return -ENOMEM; | |
343 | ||
344 | clkdev_add(cl); | |
345 | ||
346 | return 0; | |
347 | } | |
348 | ||
349 | /** | |
350 | * clk_register_clkdevs - register a set of clk_lookup for a struct clk | |
351 | * @clk: struct clk to associate with all clk_lookups | |
352 | * @cl: array of clk_lookup structures with con_id and dev_id pre-initialized | |
353 | * @num: number of clk_lookup structures to register | |
354 | * | |
355 | * To make things easier for mass registration, we detect error clks | |
356 | * from a previous clk_register() call, and return the error code for | |
357 | * those. This is to permit this function to be called immediately | |
358 | * after clk_register(). | |
359 | */ | |
360 | int clk_register_clkdevs(struct clk *clk, struct clk_lookup *cl, size_t num) | |
361 | { | |
362 | unsigned i; | |
363 | ||
364 | if (IS_ERR(clk)) | |
365 | return PTR_ERR(clk); | |
366 | ||
367 | for (i = 0; i < num; i++, cl++) { | |
368 | cl->clk = clk; | |
369 | clkdev_add(cl); | |
370 | } | |
371 | ||
372 | return 0; | |
373 | } | |
374 | EXPORT_SYMBOL(clk_register_clkdevs); |