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Russell King0318e692008-11-09 16:32:46 +00001/*
Jean-Christop PLAGNIOL-VILLARD6d803ba2010-11-17 10:04:33 +01002 * drivers/clk/clkdev.c
Russell King0318e692008-11-09 16:32:46 +00003 *
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>
Hartley Sweetenc0c60c42009-08-04 23:38:06 +010020#include <linux/clk.h>
Jean-Christop PLAGNIOL-VILLARD6d803ba2010-11-17 10:04:33 +010021#include <linux/clkdev.h>
Tomeu Vizoso035a61c2015-01-23 12:03:30 +010022#include <linux/clk-provider.h>
Grant Likely766e6a42012-04-09 14:50:06 -050023#include <linux/of.h>
Russell King0318e692008-11-09 16:32:46 +000024
Sylwester Nawrocki3a3d2b02013-08-23 17:03:44 +020025#include "clk.h"
26
Russell King0318e692008-11-09 16:32:46 +000027static LIST_HEAD(clocks);
28static DEFINE_MUTEX(clocks_mutex);
29
Rob Herring137f8a72012-07-18 11:52:23 +080030#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
Stephen Boyd73e0e492015-02-06 11:42:43 -080031static struct clk *__of_clk_get(struct device_node *np, int index,
32 const char *dev_id, const char *con_id)
Grant Likely766e6a42012-04-09 14:50:06 -050033{
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
Stephen Boyd306c3422015-02-05 15:39:11 -080046 clk = __of_clk_get_from_provider(&clkspec, dev_id, con_id);
Grant Likely766e6a42012-04-09 14:50:06 -050047 of_node_put(clkspec.np);
Tomeu Vizoso035a61c2015-01-23 12:03:30 +010048
49 return clk;
50}
51
52struct clk *of_clk_get(struct device_node *np, int index)
53{
Stephen Boyd73e0e492015-02-06 11:42:43 -080054 return __of_clk_get(np, index, np->full_name, NULL);
Grant Likely766e6a42012-04-09 14:50:06 -050055}
56EXPORT_SYMBOL(of_clk_get);
57
Tomeu Vizoso035a61c2015-01-23 12:03:30 +010058static struct clk *__of_clk_get_by_name(struct device_node *np,
59 const char *dev_id,
60 const char *name)
Grant Likely766e6a42012-04-09 14:50:06 -050061{
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);
Stephen Boyd73e0e492015-02-06 11:42:43 -080075 clk = __of_clk_get(np, index, dev_id, name);
Tomeu Vizoso035a61c2015-01-23 12:03:30 +010076 if (!IS_ERR(clk)) {
Grant Likely766e6a42012-04-09 14:50:06 -050077 break;
Stephen Boyd73e0e492015-02-06 11:42:43 -080078 } else if (name && index >= 0) {
Stephen Boydd8e53c32014-06-13 16:36:31 -070079 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);
Grant Likely766e6a42012-04-09 14:50:06 -050082 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}
Tomeu Vizoso035a61c2015-01-23 12:03:30 +010097
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}
Grant Likely766e6a42012-04-09 14:50:06 -0500114EXPORT_SYMBOL(of_clk_get_by_name);
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100115
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}
Grant Likely766e6a42012-04-09 14:50:06 -0500124#endif
125
Russell King409dc362009-01-24 10:14:37 +0000126/*
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
Uwe Kleine-König659431f2010-01-18 16:02:48 +0100133 * order of precedence: dev+con > dev only > con only.
Russell King409dc362009-01-24 10:14:37 +0000134 */
Russell Kinge8bf8df2011-04-30 10:14:08 +0100135static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
Russell King0318e692008-11-09 16:32:46 +0000136{
Russell Kinge8bf8df2011-04-30 10:14:08 +0100137 struct clk_lookup *p, *cl = NULL;
viresh kumar67b50872012-04-19 04:23:25 +0100138 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;
Russell King0318e692008-11-09 16:32:46 +0000144
145 list_for_each_entry(p, &clocks, node) {
Russell King0318e692008-11-09 16:32:46 +0000146 match = 0;
Russell King409dc362009-01-24 10:14:37 +0000147 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 }
Russell King0318e692008-11-09 16:32:46 +0000157
viresh kumar67b50872012-04-19 04:23:25 +0100158 if (match > best_found) {
Russell Kinge8bf8df2011-04-30 10:14:08 +0100159 cl = p;
viresh kumar67b50872012-04-19 04:23:25 +0100160 if (match != best_possible)
161 best_found = match;
viresh kumare4bf5be2010-03-09 11:54:30 +0100162 else
163 break;
Russell King0318e692008-11-09 16:32:46 +0000164 }
165 }
Russell Kinge8bf8df2011-04-30 10:14:08 +0100166 return cl;
Russell King0318e692008-11-09 16:32:46 +0000167}
168
Sascha Hauer05fd8e72009-03-07 12:55:49 +0100169struct clk *clk_get_sys(const char *dev_id, const char *con_id)
Russell King0318e692008-11-09 16:32:46 +0000170{
Russell Kinge8bf8df2011-04-30 10:14:08 +0100171 struct clk_lookup *cl;
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100172 struct clk *clk = NULL;
Russell King0318e692008-11-09 16:32:46 +0000173
174 mutex_lock(&clocks_mutex);
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100175
Russell Kinge8bf8df2011-04-30 10:14:08 +0100176 cl = clk_find(dev_id, con_id);
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100177 if (!cl)
178 goto out;
179
Russell Kingd5622a92015-03-02 15:45:41 +0000180 clk = __clk_create_clk(cl->clk_hw, dev_id, con_id);
Stephen Boyd73e0e492015-02-06 11:42:43 -0800181 if (IS_ERR(clk))
182 goto out;
183
184 if (!__clk_get(clk)) {
185 __clk_free_clk(clk);
Russell Kinge8bf8df2011-04-30 10:14:08 +0100186 cl = NULL;
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100187 goto out;
188 }
189
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100190out:
Russell King0318e692008-11-09 16:32:46 +0000191 mutex_unlock(&clocks_mutex);
192
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100193 return cl ? clk : ERR_PTR(-ENOENT);
Russell King0318e692008-11-09 16:32:46 +0000194}
Sascha Hauer05fd8e72009-03-07 12:55:49 +0100195EXPORT_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;
Grant Likely766e6a42012-04-09 14:50:06 -0500200 struct clk *clk;
201
202 if (dev) {
Tomeu Vizoso035a61c2015-01-23 12:03:30 +0100203 clk = __of_clk_get_by_name(dev->of_node, dev_id, con_id);
204 if (!IS_ERR(clk) || PTR_ERR(clk) == -EPROBE_DEFER)
Jean-Francois Moinea34cd462013-11-25 19:47:04 +0100205 return clk;
Grant Likely766e6a42012-04-09 14:50:06 -0500206 }
Sascha Hauer05fd8e72009-03-07 12:55:49 +0100207
208 return clk_get_sys(dev_id, con_id);
209}
Russell King0318e692008-11-09 16:32:46 +0000210EXPORT_SYMBOL(clk_get);
211
212void clk_put(struct clk *clk)
213{
214 __clk_put(clk);
215}
216EXPORT_SYMBOL(clk_put);
217
Russell Kingd5622a92015-03-02 15:45:41 +0000218static void __clkdev_add(struct clk_lookup *cl)
Russell King0318e692008-11-09 16:32:46 +0000219{
220 mutex_lock(&clocks_mutex);
221 list_add_tail(&cl->node, &clocks);
222 mutex_unlock(&clocks_mutex);
223}
Russell Kingd5622a92015-03-02 15:45:41 +0000224
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}
Russell King0318e692008-11-09 16:32:46 +0000231EXPORT_SYMBOL(clkdev_add);
232
Russell Kingfba3acd2015-03-10 14:34:00 +0000233void clkdev_add_table(struct clk_lookup *cl, size_t num)
Russell King0a0300d2010-01-12 12:28:00 +0000234{
235 mutex_lock(&clocks_mutex);
236 while (num--) {
Russell Kingd5622a92015-03-02 15:45:41 +0000237 cl->clk_hw = __clk_get_hw(cl->clk);
Russell King0a0300d2010-01-12 12:28:00 +0000238 list_add_tail(&cl->node, &clocks);
239 cl++;
240 }
241 mutex_unlock(&clocks_mutex);
242}
243
Russell King0318e692008-11-09 16:32:46 +0000244#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
Russell Kinge9d7f402012-05-02 09:30:32 +0100253static struct clk_lookup * __init_refok
Russell Kingd5622a92015-03-02 15:45:41 +0000254vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt,
Russell Kinge9d7f402012-05-02 09:30:32 +0100255 va_list ap)
Russell King0318e692008-11-09 16:32:46 +0000256{
257 struct clk_lookup_alloc *cla;
258
Jean-Christop PLAGNIOL-VILLARD6d803ba2010-11-17 10:04:33 +0100259 cla = __clkdev_alloc(sizeof(*cla));
Russell King0318e692008-11-09 16:32:46 +0000260 if (!cla)
261 return NULL;
262
Russell Kingd5622a92015-03-02 15:45:41 +0000263 cla->cl.clk_hw = hw;
Russell King0318e692008-11-09 16:32:46 +0000264 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) {
Russell King0318e692008-11-09 16:32:46 +0000270 vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
271 cla->cl.dev_id = cla->dev_id;
Russell King0318e692008-11-09 16:32:46 +0000272 }
273
274 return &cla->cl;
275}
Russell Kinge9d7f402012-05-02 09:30:32 +0100276
Russell King25689992015-03-02 15:40:29 +0000277static 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
Russell Kinge9d7f402012-05-02 09:30:32 +0100290struct clk_lookup * __init_refok
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);
Russell Kingd5622a92015-03-02 15:45:41 +0000297 cl = vclkdev_alloc(__clk_get_hw(clk), con_id, dev_fmt, ap);
Russell Kinge9d7f402012-05-02 09:30:32 +0100298 va_end(ap);
299
300 return cl;
301}
Russell King0318e692008-11-09 16:32:46 +0000302EXPORT_SYMBOL(clkdev_alloc);
303
Russell King25689992015-03-02 15:40:29 +0000304/**
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
309 *
310 * Returns a clk_lookup structure, which can be later unregistered and
311 * freed.
312 */
313struct clk_lookup *clkdev_create(struct clk *clk, const char *con_id,
314 const char *dev_fmt, ...)
315{
316 struct clk_lookup *cl;
317 va_list ap;
318
319 va_start(ap, dev_fmt);
320 cl = vclkdev_create(__clk_get_hw(clk), con_id, dev_fmt, ap);
321 va_end(ap);
322
323 return cl;
324}
325EXPORT_SYMBOL_GPL(clkdev_create);
326
Russell Kingb3d8d7e2015-03-09 10:43:04 +0000327int clk_add_alias(const char *alias, const char *alias_dev_name,
328 const char *con_id, struct device *dev)
Tony Lindgrenc0683032009-06-03 17:43:14 +0100329{
Russell Kingb3d8d7e2015-03-09 10:43:04 +0000330 struct clk *r = clk_get(dev, con_id);
Tony Lindgrenc0683032009-06-03 17:43:14 +0100331 struct clk_lookup *l;
332
333 if (IS_ERR(r))
334 return PTR_ERR(r);
335
Russell King25689992015-03-02 15:40:29 +0000336 l = clkdev_create(r, alias, "%s", alias_dev_name);
Tony Lindgrenc0683032009-06-03 17:43:14 +0100337 clk_put(r);
Russell King25689992015-03-02 15:40:29 +0000338
339 return l ? 0 : -ENODEV;
Tony Lindgrenc0683032009-06-03 17:43:14 +0100340}
341EXPORT_SYMBOL(clk_add_alias);
342
Russell King0318e692008-11-09 16:32:46 +0000343/*
344 * clkdev_drop - remove a clock dynamically allocated
345 */
346void clkdev_drop(struct clk_lookup *cl)
347{
348 mutex_lock(&clocks_mutex);
349 list_del(&cl->node);
350 mutex_unlock(&clocks_mutex);
351 kfree(cl);
352}
353EXPORT_SYMBOL(clkdev_drop);
Russell Kinge9d7f402012-05-02 09:30:32 +0100354
355/**
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
360 *
361 * con_id or dev_id may be NULL as a wildcard, just as in the rest of
362 * clkdev.
363 *
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().
368 */
369int clk_register_clkdev(struct clk *clk, const char *con_id,
370 const char *dev_fmt, ...)
371{
372 struct clk_lookup *cl;
373 va_list ap;
374
375 if (IS_ERR(clk))
376 return PTR_ERR(clk);
377
378 va_start(ap, dev_fmt);
Russell King25689992015-03-02 15:40:29 +0000379 cl = vclkdev_create(__clk_get_hw(clk), con_id, dev_fmt, ap);
Russell Kinge9d7f402012-05-02 09:30:32 +0100380 va_end(ap);
381
Russell King25689992015-03-02 15:40:29 +0000382 return cl ? 0 : -ENOMEM;
Russell Kinge9d7f402012-05-02 09:30:32 +0100383}
Tomeu Vizosoa251361a2015-01-23 12:03:32 +0100384EXPORT_SYMBOL(clk_register_clkdev);
Russell Kinge9d7f402012-05-02 09:30:32 +0100385
386/**
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
391 *
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().
396 */
397int clk_register_clkdevs(struct clk *clk, struct clk_lookup *cl, size_t num)
398{
399 unsigned i;
400
401 if (IS_ERR(clk))
402 return PTR_ERR(clk);
403
404 for (i = 0; i < num; i++, cl++) {
Russell Kingd5622a92015-03-02 15:45:41 +0000405 cl->clk_hw = __clk_get_hw(clk);
406 __clkdev_add(cl);
Russell Kinge9d7f402012-05-02 09:30:32 +0100407 }
408
409 return 0;
410}
411EXPORT_SYMBOL(clk_register_clkdevs);