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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 | 23 | |
3a3d2b05 SN |
24 | #include "clk.h" |
25 | ||
0318e693 RK |
26 | static LIST_HEAD(clocks); |
27 | static DEFINE_MUTEX(clocks_mutex); | |
28 | ||
137f8a72 | 29 | #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) |
7f05e28f SN |
30 | |
31 | /** | |
32 | * of_clk_get_by_clkspec() - Lookup a clock form a clock provider | |
33 | * @clkspec: pointer to a clock specifier data structure | |
34 | * | |
35 | * This function looks up a struct clk from the registered list of clock | |
36 | * providers, an input is a clock specifier data structure as returned | |
37 | * from the of_parse_phandle_with_args() function call. | |
38 | */ | |
39 | struct clk *of_clk_get_by_clkspec(struct of_phandle_args *clkspec) | |
40 | { | |
41 | struct clk *clk; | |
42 | ||
43 | if (!clkspec) | |
44 | return ERR_PTR(-EINVAL); | |
45 | ||
46 | of_clk_lock(); | |
47 | clk = __of_clk_get_from_provider(clkspec); | |
48 | ||
49 | if (!IS_ERR(clk) && !__clk_get(clk)) | |
50 | clk = ERR_PTR(-ENOENT); | |
51 | ||
52 | of_clk_unlock(); | |
53 | return clk; | |
54 | } | |
55 | ||
766e6a4e GL |
56 | struct clk *of_clk_get(struct device_node *np, int index) |
57 | { | |
58 | struct of_phandle_args clkspec; | |
59 | struct clk *clk; | |
60 | int rc; | |
61 | ||
62 | if (index < 0) | |
63 | return ERR_PTR(-EINVAL); | |
64 | ||
65 | rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, | |
66 | &clkspec); | |
67 | if (rc) | |
68 | return ERR_PTR(rc); | |
69 | ||
7f05e28f | 70 | clk = of_clk_get_by_clkspec(&clkspec); |
766e6a4e GL |
71 | of_node_put(clkspec.np); |
72 | return clk; | |
73 | } | |
74 | EXPORT_SYMBOL(of_clk_get); | |
75 | ||
76 | /** | |
77 | * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node | |
78 | * @np: pointer to clock consumer node | |
79 | * @name: name of consumer's clock input, or NULL for the first clock reference | |
80 | * | |
81 | * This function parses the clocks and clock-names properties, | |
82 | * and uses them to look up the struct clk from the registered list of clock | |
83 | * providers. | |
84 | */ | |
85 | struct clk *of_clk_get_by_name(struct device_node *np, const char *name) | |
86 | { | |
87 | struct clk *clk = ERR_PTR(-ENOENT); | |
88 | ||
89 | /* Walk up the tree of devices looking for a clock that matches */ | |
90 | while (np) { | |
91 | int index = 0; | |
92 | ||
93 | /* | |
94 | * For named clocks, first look up the name in the | |
95 | * "clock-names" property. If it cannot be found, then | |
96 | * index will be an error code, and of_clk_get() will fail. | |
97 | */ | |
98 | if (name) | |
99 | index = of_property_match_string(np, "clock-names", name); | |
100 | clk = of_clk_get(np, index); | |
101 | if (!IS_ERR(clk)) | |
102 | break; | |
103 | else if (name && index >= 0) { | |
d8e53c3d SB |
104 | if (PTR_ERR(clk) != -EPROBE_DEFER) |
105 | pr_err("ERROR: could not get clock %s:%s(%i)\n", | |
106 | np->full_name, name ? name : "", index); | |
766e6a4e GL |
107 | return clk; |
108 | } | |
109 | ||
110 | /* | |
111 | * No matching clock found on this node. If the parent node | |
112 | * has a "clock-ranges" property, then we can try one of its | |
113 | * clocks. | |
114 | */ | |
115 | np = np->parent; | |
116 | if (np && !of_get_property(np, "clock-ranges", NULL)) | |
117 | break; | |
118 | } | |
119 | ||
120 | return clk; | |
121 | } | |
122 | EXPORT_SYMBOL(of_clk_get_by_name); | |
123 | #endif | |
124 | ||
409dc360 RK |
125 | /* |
126 | * Find the correct struct clk for the device and connection ID. | |
127 | * We do slightly fuzzy matching here: | |
128 | * An entry with a NULL ID is assumed to be a wildcard. | |
129 | * If an entry has a device ID, it must match | |
130 | * If an entry has a connection ID, it must match | |
131 | * Then we take the most specific entry - with the following | |
659431fc | 132 | * order of precedence: dev+con > dev only > con only. |
409dc360 | 133 | */ |
e8bf8df9 | 134 | static struct clk_lookup *clk_find(const char *dev_id, const char *con_id) |
0318e693 | 135 | { |
e8bf8df9 | 136 | struct clk_lookup *p, *cl = NULL; |
67b50871 VK |
137 | int match, best_found = 0, best_possible = 0; |
138 | ||
139 | if (dev_id) | |
140 | best_possible += 2; | |
141 | if (con_id) | |
142 | best_possible += 1; | |
0318e693 RK |
143 | |
144 | list_for_each_entry(p, &clocks, node) { | |
0318e693 | 145 | match = 0; |
409dc360 RK |
146 | if (p->dev_id) { |
147 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
148 | continue; | |
149 | match += 2; | |
150 | } | |
151 | if (p->con_id) { | |
152 | if (!con_id || strcmp(p->con_id, con_id)) | |
153 | continue; | |
154 | match += 1; | |
155 | } | |
0318e693 | 156 | |
67b50871 | 157 | if (match > best_found) { |
e8bf8df9 | 158 | cl = p; |
67b50871 VK |
159 | if (match != best_possible) |
160 | best_found = match; | |
e4bf5bec VK |
161 | else |
162 | break; | |
0318e693 RK |
163 | } |
164 | } | |
e8bf8df9 | 165 | return cl; |
0318e693 RK |
166 | } |
167 | ||
05fd8e73 | 168 | struct clk *clk_get_sys(const char *dev_id, const char *con_id) |
0318e693 | 169 | { |
e8bf8df9 | 170 | struct clk_lookup *cl; |
0318e693 RK |
171 | |
172 | mutex_lock(&clocks_mutex); | |
e8bf8df9 RK |
173 | cl = clk_find(dev_id, con_id); |
174 | if (cl && !__clk_get(cl->clk)) | |
175 | cl = NULL; | |
0318e693 RK |
176 | mutex_unlock(&clocks_mutex); |
177 | ||
e8bf8df9 | 178 | return cl ? cl->clk : ERR_PTR(-ENOENT); |
0318e693 | 179 | } |
05fd8e73 SH |
180 | EXPORT_SYMBOL(clk_get_sys); |
181 | ||
182 | struct clk *clk_get(struct device *dev, const char *con_id) | |
183 | { | |
184 | const char *dev_id = dev ? dev_name(dev) : NULL; | |
766e6a4e GL |
185 | struct clk *clk; |
186 | ||
187 | if (dev) { | |
188 | clk = of_clk_get_by_name(dev->of_node, con_id); | |
3a3d2b05 | 189 | if (!IS_ERR(clk)) |
766e6a4e | 190 | return clk; |
a34cd466 JFM |
191 | if (PTR_ERR(clk) == -EPROBE_DEFER) |
192 | return clk; | |
766e6a4e | 193 | } |
05fd8e73 SH |
194 | |
195 | return clk_get_sys(dev_id, con_id); | |
196 | } | |
0318e693 RK |
197 | EXPORT_SYMBOL(clk_get); |
198 | ||
199 | void clk_put(struct clk *clk) | |
200 | { | |
201 | __clk_put(clk); | |
202 | } | |
203 | EXPORT_SYMBOL(clk_put); | |
204 | ||
205 | void clkdev_add(struct clk_lookup *cl) | |
206 | { | |
207 | mutex_lock(&clocks_mutex); | |
208 | list_add_tail(&cl->node, &clocks); | |
209 | mutex_unlock(&clocks_mutex); | |
210 | } | |
211 | EXPORT_SYMBOL(clkdev_add); | |
212 | ||
0a0300dc RK |
213 | void __init clkdev_add_table(struct clk_lookup *cl, size_t num) |
214 | { | |
215 | mutex_lock(&clocks_mutex); | |
216 | while (num--) { | |
217 | list_add_tail(&cl->node, &clocks); | |
218 | cl++; | |
219 | } | |
220 | mutex_unlock(&clocks_mutex); | |
221 | } | |
222 | ||
0318e693 RK |
223 | #define MAX_DEV_ID 20 |
224 | #define MAX_CON_ID 16 | |
225 | ||
226 | struct clk_lookup_alloc { | |
227 | struct clk_lookup cl; | |
228 | char dev_id[MAX_DEV_ID]; | |
229 | char con_id[MAX_CON_ID]; | |
230 | }; | |
231 | ||
e9d7f406 RK |
232 | static struct clk_lookup * __init_refok |
233 | vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, | |
234 | va_list ap) | |
0318e693 RK |
235 | { |
236 | struct clk_lookup_alloc *cla; | |
237 | ||
6d803ba7 | 238 | cla = __clkdev_alloc(sizeof(*cla)); |
0318e693 RK |
239 | if (!cla) |
240 | return NULL; | |
241 | ||
242 | cla->cl.clk = clk; | |
243 | if (con_id) { | |
244 | strlcpy(cla->con_id, con_id, sizeof(cla->con_id)); | |
245 | cla->cl.con_id = cla->con_id; | |
246 | } | |
247 | ||
248 | if (dev_fmt) { | |
0318e693 RK |
249 | vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap); |
250 | cla->cl.dev_id = cla->dev_id; | |
0318e693 RK |
251 | } |
252 | ||
253 | return &cla->cl; | |
254 | } | |
e9d7f406 RK |
255 | |
256 | struct clk_lookup * __init_refok | |
257 | clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...) | |
258 | { | |
259 | struct clk_lookup *cl; | |
260 | va_list ap; | |
261 | ||
262 | va_start(ap, dev_fmt); | |
263 | cl = vclkdev_alloc(clk, con_id, dev_fmt, ap); | |
264 | va_end(ap); | |
265 | ||
266 | return cl; | |
267 | } | |
0318e693 RK |
268 | EXPORT_SYMBOL(clkdev_alloc); |
269 | ||
c0683039 TL |
270 | int clk_add_alias(const char *alias, const char *alias_dev_name, char *id, |
271 | struct device *dev) | |
272 | { | |
273 | struct clk *r = clk_get(dev, id); | |
274 | struct clk_lookup *l; | |
275 | ||
276 | if (IS_ERR(r)) | |
277 | return PTR_ERR(r); | |
278 | ||
279 | l = clkdev_alloc(r, alias, alias_dev_name); | |
280 | clk_put(r); | |
281 | if (!l) | |
282 | return -ENODEV; | |
283 | clkdev_add(l); | |
284 | return 0; | |
285 | } | |
286 | EXPORT_SYMBOL(clk_add_alias); | |
287 | ||
0318e693 RK |
288 | /* |
289 | * clkdev_drop - remove a clock dynamically allocated | |
290 | */ | |
291 | void clkdev_drop(struct clk_lookup *cl) | |
292 | { | |
293 | mutex_lock(&clocks_mutex); | |
294 | list_del(&cl->node); | |
295 | mutex_unlock(&clocks_mutex); | |
296 | kfree(cl); | |
297 | } | |
298 | EXPORT_SYMBOL(clkdev_drop); | |
e9d7f406 RK |
299 | |
300 | /** | |
301 | * clk_register_clkdev - register one clock lookup for a struct clk | |
302 | * @clk: struct clk to associate with all clk_lookups | |
303 | * @con_id: connection ID string on device | |
304 | * @dev_id: format string describing device name | |
305 | * | |
306 | * con_id or dev_id may be NULL as a wildcard, just as in the rest of | |
307 | * clkdev. | |
308 | * | |
309 | * To make things easier for mass registration, we detect error clks | |
310 | * from a previous clk_register() call, and return the error code for | |
311 | * those. This is to permit this function to be called immediately | |
312 | * after clk_register(). | |
313 | */ | |
314 | int clk_register_clkdev(struct clk *clk, const char *con_id, | |
315 | const char *dev_fmt, ...) | |
316 | { | |
317 | struct clk_lookup *cl; | |
318 | va_list ap; | |
319 | ||
320 | if (IS_ERR(clk)) | |
321 | return PTR_ERR(clk); | |
322 | ||
323 | va_start(ap, dev_fmt); | |
324 | cl = vclkdev_alloc(clk, con_id, dev_fmt, ap); | |
325 | va_end(ap); | |
326 | ||
327 | if (!cl) | |
328 | return -ENOMEM; | |
329 | ||
330 | clkdev_add(cl); | |
331 | ||
332 | return 0; | |
333 | } | |
334 | ||
335 | /** | |
336 | * clk_register_clkdevs - register a set of clk_lookup for a struct clk | |
337 | * @clk: struct clk to associate with all clk_lookups | |
338 | * @cl: array of clk_lookup structures with con_id and dev_id pre-initialized | |
339 | * @num: number of clk_lookup structures to register | |
340 | * | |
341 | * To make things easier for mass registration, we detect error clks | |
342 | * from a previous clk_register() call, and return the error code for | |
343 | * those. This is to permit this function to be called immediately | |
344 | * after clk_register(). | |
345 | */ | |
346 | int clk_register_clkdevs(struct clk *clk, struct clk_lookup *cl, size_t num) | |
347 | { | |
348 | unsigned i; | |
349 | ||
350 | if (IS_ERR(clk)) | |
351 | return PTR_ERR(clk); | |
352 | ||
353 | for (i = 0; i < num; i++, cl++) { | |
354 | cl->clk = clk; | |
355 | clkdev_add(cl); | |
356 | } | |
357 | ||
358 | return 0; | |
359 | } | |
360 | EXPORT_SYMBOL(clk_register_clkdevs); |