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1/*
2 * drivers/clk/clkdev.c
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>
20#include <linux/clk.h>
21#include <linux/clkdev.h>
22
23static LIST_HEAD(clocks);
24static DEFINE_MUTEX(clocks_mutex);
25
26/*
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.
34 */
35static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
36{
37 struct clk_lookup *p, *cl = NULL;
38 int match, best = 0;
39
40 list_for_each_entry(p, &clocks, node) {
41 match = 0;
42 if (p->dev_id) {
43 if (!dev_id || strcmp(p->dev_id, dev_id))
44 continue;
45 match += 2;
46 }
47 if (p->con_id) {
48 if (!con_id || strcmp(p->con_id, con_id))
49 continue;
50 match += 1;
51 }
52
53 if (match > best) {
54 cl = p;
55 if (match != 3)
56 best = match;
57 else
58 break;
59 }
60 }
61 return cl;
62}
63
64struct clk *clk_get_sys(const char *dev_id, const char *con_id)
65{
66 struct clk_lookup *cl;
67
68 mutex_lock(&clocks_mutex);
69 cl = clk_find(dev_id, con_id);
70 if (cl && !__clk_get(cl->clk))
71 cl = NULL;
72 mutex_unlock(&clocks_mutex);
73
74 return cl ? cl->clk : ERR_PTR(-ENOENT);
75}
76EXPORT_SYMBOL(clk_get_sys);
77
78struct clk *clk_get(struct device *dev, const char *con_id)
79{
80 const char *dev_id = dev ? dev_name(dev) : NULL;
81
82 return clk_get_sys(dev_id, con_id);
83}
84EXPORT_SYMBOL(clk_get);
85
86void clk_put(struct clk *clk)
87{
88 __clk_put(clk);
89}
90EXPORT_SYMBOL(clk_put);
91
92void clkdev_add(struct clk_lookup *cl)
93{
94 mutex_lock(&clocks_mutex);
95 list_add_tail(&cl->node, &clocks);
96 mutex_unlock(&clocks_mutex);
97}
98EXPORT_SYMBOL(clkdev_add);
99
100void __init clkdev_add_table(struct clk_lookup *cl, size_t num)
101{
102 mutex_lock(&clocks_mutex);
103 while (num--) {
104 list_add_tail(&cl->node, &clocks);
105 cl++;
106 }
107 mutex_unlock(&clocks_mutex);
108}
109
110#define MAX_DEV_ID 20
111#define MAX_CON_ID 16
112
113struct clk_lookup_alloc {
114 struct clk_lookup cl;
115 char dev_id[MAX_DEV_ID];
116 char con_id[MAX_CON_ID];
117};
118
119struct clk_lookup * __init_refok
120clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)
121{
122 struct clk_lookup_alloc *cla;
123
124 cla = __clkdev_alloc(sizeof(*cla));
125 if (!cla)
126 return NULL;
127
128 cla->cl.clk = clk;
129 if (con_id) {
130 strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
131 cla->cl.con_id = cla->con_id;
132 }
133
134 if (dev_fmt) {
135 va_list ap;
136
137 va_start(ap, dev_fmt);
138 vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
139 cla->cl.dev_id = cla->dev_id;
140 va_end(ap);
141 }
142
143 return &cla->cl;
144}
145EXPORT_SYMBOL(clkdev_alloc);
146
147int clk_add_alias(const char *alias, const char *alias_dev_name, char *id,
148 struct device *dev)
149{
150 struct clk *r = clk_get(dev, id);
151 struct clk_lookup *l;
152
153 if (IS_ERR(r))
154 return PTR_ERR(r);
155
156 l = clkdev_alloc(r, alias, alias_dev_name);
157 clk_put(r);
158 if (!l)
159 return -ENODEV;
160 clkdev_add(l);
161 return 0;
162}
163EXPORT_SYMBOL(clk_add_alias);
164
165/*
166 * clkdev_drop - remove a clock dynamically allocated
167 */
168void clkdev_drop(struct clk_lookup *cl)
169{
170 mutex_lock(&clocks_mutex);
171 list_del(&cl->node);
172 mutex_unlock(&clocks_mutex);
173 kfree(cl);
174}
175EXPORT_SYMBOL(clkdev_drop);
1/*
2 * drivers/clk/clkdev.c
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>
20#include <linux/clk.h>
21#include <linux/clkdev.h>
22#include <linux/clk-provider.h>
23#include <linux/of.h>
24
25#include "clk.h"
26
27static LIST_HEAD(clocks);
28static DEFINE_MUTEX(clocks_mutex);
29
30#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
31static struct clk *__of_clk_get(struct device_node *np, int index,
32 const char *dev_id, const char *con_id)
33{
34 struct of_phandle_args clkspec;
35 struct clk *clk;
36 int rc;
37
38 if (index < 0)
39 return ERR_PTR(-EINVAL);
40
41 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
42 &clkspec);
43 if (rc)
44 return ERR_PTR(rc);
45
46 clk = __of_clk_get_from_provider(&clkspec, dev_id, con_id);
47 of_node_put(clkspec.np);
48
49 return clk;
50}
51
52struct clk *of_clk_get(struct device_node *np, int index)
53{
54 return __of_clk_get(np, index, np->full_name, NULL);
55}
56EXPORT_SYMBOL(of_clk_get);
57
58static struct clk *__of_clk_get_by_name(struct device_node *np,
59 const char *dev_id,
60 const char *name)
61{
62 struct clk *clk = ERR_PTR(-ENOENT);
63
64 /* Walk up the tree of devices looking for a clock that matches */
65 while (np) {
66 int index = 0;
67
68 /*
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.
72 */
73 if (name)
74 index = of_property_match_string(np, "clock-names", name);
75 clk = __of_clk_get(np, index, dev_id, name);
76 if (!IS_ERR(clk)) {
77 break;
78 } else if (name && index >= 0) {
79 if (PTR_ERR(clk) != -EPROBE_DEFER)
80 pr_err("ERROR: could not get clock %pOF:%s(%i)\n",
81 np, name ? name : "", index);
82 return clk;
83 }
84
85 /*
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
88 * clocks.
89 */
90 np = np->parent;
91 if (np && !of_get_property(np, "clock-ranges", NULL))
92 break;
93 }
94
95 return clk;
96}
97
98/**
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
102 *
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
105 * providers.
106 */
107struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
108{
109 if (!np)
110 return ERR_PTR(-ENOENT);
111
112 return __of_clk_get_by_name(np, np->full_name, name);
113}
114EXPORT_SYMBOL(of_clk_get_by_name);
115
116#else /* defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) */
117
118static struct clk *__of_clk_get_by_name(struct device_node *np,
119 const char *dev_id,
120 const char *name)
121{
122 return ERR_PTR(-ENOENT);
123}
124#endif
125
126/*
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.
134 */
135static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
136{
137 struct clk_lookup *p, *cl = NULL;
138 int match, best_found = 0, best_possible = 0;
139
140 if (dev_id)
141 best_possible += 2;
142 if (con_id)
143 best_possible += 1;
144
145 list_for_each_entry(p, &clocks, node) {
146 match = 0;
147 if (p->dev_id) {
148 if (!dev_id || strcmp(p->dev_id, dev_id))
149 continue;
150 match += 2;
151 }
152 if (p->con_id) {
153 if (!con_id || strcmp(p->con_id, con_id))
154 continue;
155 match += 1;
156 }
157
158 if (match > best_found) {
159 cl = p;
160 if (match != best_possible)
161 best_found = match;
162 else
163 break;
164 }
165 }
166 return cl;
167}
168
169struct clk *clk_get_sys(const char *dev_id, const char *con_id)
170{
171 struct clk_lookup *cl;
172 struct clk *clk = NULL;
173
174 mutex_lock(&clocks_mutex);
175
176 cl = clk_find(dev_id, con_id);
177 if (!cl)
178 goto out;
179
180 clk = __clk_create_clk(cl->clk_hw, dev_id, con_id);
181 if (IS_ERR(clk))
182 goto out;
183
184 if (!__clk_get(clk)) {
185 __clk_free_clk(clk);
186 cl = NULL;
187 goto out;
188 }
189
190out:
191 mutex_unlock(&clocks_mutex);
192
193 return cl ? clk : ERR_PTR(-ENOENT);
194}
195EXPORT_SYMBOL(clk_get_sys);
196
197struct clk *clk_get(struct device *dev, const char *con_id)
198{
199 const char *dev_id = dev ? dev_name(dev) : NULL;
200 struct clk *clk;
201
202 if (dev) {
203 clk = __of_clk_get_by_name(dev->of_node, dev_id, con_id);
204 if (!IS_ERR(clk) || PTR_ERR(clk) == -EPROBE_DEFER)
205 return clk;
206 }
207
208 return clk_get_sys(dev_id, con_id);
209}
210EXPORT_SYMBOL(clk_get);
211
212void clk_put(struct clk *clk)
213{
214 __clk_put(clk);
215}
216EXPORT_SYMBOL(clk_put);
217
218static void __clkdev_add(struct clk_lookup *cl)
219{
220 mutex_lock(&clocks_mutex);
221 list_add_tail(&cl->node, &clocks);
222 mutex_unlock(&clocks_mutex);
223}
224
225void clkdev_add(struct clk_lookup *cl)
226{
227 if (!cl->clk_hw)
228 cl->clk_hw = __clk_get_hw(cl->clk);
229 __clkdev_add(cl);
230}
231EXPORT_SYMBOL(clkdev_add);
232
233void clkdev_add_table(struct clk_lookup *cl, size_t num)
234{
235 mutex_lock(&clocks_mutex);
236 while (num--) {
237 cl->clk_hw = __clk_get_hw(cl->clk);
238 list_add_tail(&cl->node, &clocks);
239 cl++;
240 }
241 mutex_unlock(&clocks_mutex);
242}
243
244#define MAX_DEV_ID 20
245#define MAX_CON_ID 16
246
247struct clk_lookup_alloc {
248 struct clk_lookup cl;
249 char dev_id[MAX_DEV_ID];
250 char con_id[MAX_CON_ID];
251};
252
253static struct clk_lookup * __ref
254vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt,
255 va_list ap)
256{
257 struct clk_lookup_alloc *cla;
258
259 cla = kzalloc(sizeof(*cla), GFP_KERNEL);
260 if (!cla)
261 return NULL;
262
263 cla->cl.clk_hw = hw;
264 if (con_id) {
265 strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
266 cla->cl.con_id = cla->con_id;
267 }
268
269 if (dev_fmt) {
270 vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
271 cla->cl.dev_id = cla->dev_id;
272 }
273
274 return &cla->cl;
275}
276
277static struct clk_lookup *
278vclkdev_create(struct clk_hw *hw, const char *con_id, const char *dev_fmt,
279 va_list ap)
280{
281 struct clk_lookup *cl;
282
283 cl = vclkdev_alloc(hw, con_id, dev_fmt, ap);
284 if (cl)
285 __clkdev_add(cl);
286
287 return cl;
288}
289
290struct clk_lookup * __ref
291clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)
292{
293 struct clk_lookup *cl;
294 va_list ap;
295
296 va_start(ap, dev_fmt);
297 cl = vclkdev_alloc(__clk_get_hw(clk), con_id, dev_fmt, ap);
298 va_end(ap);
299
300 return cl;
301}
302EXPORT_SYMBOL(clkdev_alloc);
303
304struct clk_lookup *
305clkdev_hw_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt, ...)
306{
307 struct clk_lookup *cl;
308 va_list ap;
309
310 va_start(ap, dev_fmt);
311 cl = vclkdev_alloc(hw, con_id, dev_fmt, ap);
312 va_end(ap);
313
314 return cl;
315}
316EXPORT_SYMBOL(clkdev_hw_alloc);
317
318/**
319 * clkdev_create - allocate and add a clkdev lookup structure
320 * @clk: struct clk to associate with all clk_lookups
321 * @con_id: connection ID string on device
322 * @dev_fmt: format string describing device name
323 *
324 * Returns a clk_lookup structure, which can be later unregistered and
325 * freed.
326 */
327struct clk_lookup *clkdev_create(struct clk *clk, const char *con_id,
328 const char *dev_fmt, ...)
329{
330 struct clk_lookup *cl;
331 va_list ap;
332
333 va_start(ap, dev_fmt);
334 cl = vclkdev_create(__clk_get_hw(clk), con_id, dev_fmt, ap);
335 va_end(ap);
336
337 return cl;
338}
339EXPORT_SYMBOL_GPL(clkdev_create);
340
341/**
342 * clkdev_hw_create - allocate and add a clkdev lookup structure
343 * @hw: struct clk_hw to associate with all clk_lookups
344 * @con_id: connection ID string on device
345 * @dev_fmt: format string describing device name
346 *
347 * Returns a clk_lookup structure, which can be later unregistered and
348 * freed.
349 */
350struct clk_lookup *clkdev_hw_create(struct clk_hw *hw, const char *con_id,
351 const char *dev_fmt, ...)
352{
353 struct clk_lookup *cl;
354 va_list ap;
355
356 va_start(ap, dev_fmt);
357 cl = vclkdev_create(hw, con_id, dev_fmt, ap);
358 va_end(ap);
359
360 return cl;
361}
362EXPORT_SYMBOL_GPL(clkdev_hw_create);
363
364int clk_add_alias(const char *alias, const char *alias_dev_name,
365 const char *con_id, struct device *dev)
366{
367 struct clk *r = clk_get(dev, con_id);
368 struct clk_lookup *l;
369
370 if (IS_ERR(r))
371 return PTR_ERR(r);
372
373 l = clkdev_create(r, alias, alias_dev_name ? "%s" : NULL,
374 alias_dev_name);
375 clk_put(r);
376
377 return l ? 0 : -ENODEV;
378}
379EXPORT_SYMBOL(clk_add_alias);
380
381/*
382 * clkdev_drop - remove a clock dynamically allocated
383 */
384void clkdev_drop(struct clk_lookup *cl)
385{
386 mutex_lock(&clocks_mutex);
387 list_del(&cl->node);
388 mutex_unlock(&clocks_mutex);
389 kfree(cl);
390}
391EXPORT_SYMBOL(clkdev_drop);
392
393static struct clk_lookup *__clk_register_clkdev(struct clk_hw *hw,
394 const char *con_id,
395 const char *dev_id, ...)
396{
397 struct clk_lookup *cl;
398 va_list ap;
399
400 va_start(ap, dev_id);
401 cl = vclkdev_create(hw, con_id, dev_id, ap);
402 va_end(ap);
403
404 return cl;
405}
406
407/**
408 * clk_register_clkdev - register one clock lookup for a struct clk
409 * @clk: struct clk to associate with all clk_lookups
410 * @con_id: connection ID string on device
411 * @dev_id: string describing device name
412 *
413 * con_id or dev_id may be NULL as a wildcard, just as in the rest of
414 * clkdev.
415 *
416 * To make things easier for mass registration, we detect error clks
417 * from a previous clk_register() call, and return the error code for
418 * those. This is to permit this function to be called immediately
419 * after clk_register().
420 */
421int clk_register_clkdev(struct clk *clk, const char *con_id,
422 const char *dev_id)
423{
424 struct clk_lookup *cl;
425
426 if (IS_ERR(clk))
427 return PTR_ERR(clk);
428
429 /*
430 * Since dev_id can be NULL, and NULL is handled specially, we must
431 * pass it as either a NULL format string, or with "%s".
432 */
433 if (dev_id)
434 cl = __clk_register_clkdev(__clk_get_hw(clk), con_id, "%s",
435 dev_id);
436 else
437 cl = __clk_register_clkdev(__clk_get_hw(clk), con_id, NULL);
438
439 return cl ? 0 : -ENOMEM;
440}
441EXPORT_SYMBOL(clk_register_clkdev);
442
443/**
444 * clk_hw_register_clkdev - register one clock lookup for a struct clk_hw
445 * @hw: struct clk_hw to associate with all clk_lookups
446 * @con_id: connection ID string on device
447 * @dev_id: format string describing device name
448 *
449 * con_id or dev_id may be NULL as a wildcard, just as in the rest of
450 * clkdev.
451 *
452 * To make things easier for mass registration, we detect error clk_hws
453 * from a previous clk_hw_register_*() call, and return the error code for
454 * those. This is to permit this function to be called immediately
455 * after clk_hw_register_*().
456 */
457int clk_hw_register_clkdev(struct clk_hw *hw, const char *con_id,
458 const char *dev_id)
459{
460 struct clk_lookup *cl;
461
462 if (IS_ERR(hw))
463 return PTR_ERR(hw);
464
465 /*
466 * Since dev_id can be NULL, and NULL is handled specially, we must
467 * pass it as either a NULL format string, or with "%s".
468 */
469 if (dev_id)
470 cl = __clk_register_clkdev(hw, con_id, "%s", dev_id);
471 else
472 cl = __clk_register_clkdev(hw, con_id, NULL);
473
474 return cl ? 0 : -ENOMEM;
475}
476EXPORT_SYMBOL(clk_hw_register_clkdev);