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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>
Grant Likely766e6a42012-04-09 14:50:06 -050022#include <linux/of.h>
Russell King0318e692008-11-09 16:32:46 +000023
Sylwester Nawrocki3a3d2b02013-08-23 17:03:44 +020024#include "clk.h"
25
Russell King0318e692008-11-09 16:32:46 +000026static LIST_HEAD(clocks);
27static DEFINE_MUTEX(clocks_mutex);
28
Rob Herring137f8a72012-07-18 11:52:23 +080029#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
Grant Likely766e6a42012-04-09 14:50:06 -050030struct clk *of_clk_get(struct device_node *np, int index)
31{
32 struct of_phandle_args clkspec;
33 struct clk *clk;
34 int rc;
35
36 if (index < 0)
37 return ERR_PTR(-EINVAL);
38
39 rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index,
40 &clkspec);
41 if (rc)
42 return ERR_PTR(rc);
43
Sylwester Nawrocki3a3d2b02013-08-23 17:03:44 +020044 of_clk_lock();
45 clk = __of_clk_get_from_provider(&clkspec);
46
47 if (!IS_ERR(clk) && !__clk_get(clk))
48 clk = ERR_PTR(-ENOENT);
49
50 of_clk_unlock();
Grant Likely766e6a42012-04-09 14:50:06 -050051 of_node_put(clkspec.np);
52 return clk;
53}
54EXPORT_SYMBOL(of_clk_get);
55
56/**
57 * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node
58 * @np: pointer to clock consumer node
59 * @name: name of consumer's clock input, or NULL for the first clock reference
60 *
61 * This function parses the clocks and clock-names properties,
62 * and uses them to look up the struct clk from the registered list of clock
63 * providers.
64 */
65struct clk *of_clk_get_by_name(struct device_node *np, const char *name)
66{
67 struct clk *clk = ERR_PTR(-ENOENT);
68
69 /* Walk up the tree of devices looking for a clock that matches */
70 while (np) {
71 int index = 0;
72
73 /*
74 * For named clocks, first look up the name in the
75 * "clock-names" property. If it cannot be found, then
76 * index will be an error code, and of_clk_get() will fail.
77 */
78 if (name)
79 index = of_property_match_string(np, "clock-names", name);
80 clk = of_clk_get(np, index);
81 if (!IS_ERR(clk))
82 break;
83 else if (name && index >= 0) {
84 pr_err("ERROR: could not get clock %s:%s(%i)\n",
85 np->full_name, name ? name : "", index);
86 return clk;
87 }
88
89 /*
90 * No matching clock found on this node. If the parent node
91 * has a "clock-ranges" property, then we can try one of its
92 * clocks.
93 */
94 np = np->parent;
95 if (np && !of_get_property(np, "clock-ranges", NULL))
96 break;
97 }
98
99 return clk;
100}
101EXPORT_SYMBOL(of_clk_get_by_name);
102#endif
103
Russell King409dc362009-01-24 10:14:37 +0000104/*
105 * Find the correct struct clk for the device and connection ID.
106 * We do slightly fuzzy matching here:
107 * An entry with a NULL ID is assumed to be a wildcard.
108 * If an entry has a device ID, it must match
109 * If an entry has a connection ID, it must match
110 * Then we take the most specific entry - with the following
Uwe Kleine-König659431f2010-01-18 16:02:48 +0100111 * order of precedence: dev+con > dev only > con only.
Russell King409dc362009-01-24 10:14:37 +0000112 */
Russell Kinge8bf8df2011-04-30 10:14:08 +0100113static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
Russell King0318e692008-11-09 16:32:46 +0000114{
Russell Kinge8bf8df2011-04-30 10:14:08 +0100115 struct clk_lookup *p, *cl = NULL;
viresh kumar67b50872012-04-19 04:23:25 +0100116 int match, best_found = 0, best_possible = 0;
117
118 if (dev_id)
119 best_possible += 2;
120 if (con_id)
121 best_possible += 1;
Russell King0318e692008-11-09 16:32:46 +0000122
123 list_for_each_entry(p, &clocks, node) {
Russell King0318e692008-11-09 16:32:46 +0000124 match = 0;
Russell King409dc362009-01-24 10:14:37 +0000125 if (p->dev_id) {
126 if (!dev_id || strcmp(p->dev_id, dev_id))
127 continue;
128 match += 2;
129 }
130 if (p->con_id) {
131 if (!con_id || strcmp(p->con_id, con_id))
132 continue;
133 match += 1;
134 }
Russell King0318e692008-11-09 16:32:46 +0000135
viresh kumar67b50872012-04-19 04:23:25 +0100136 if (match > best_found) {
Russell Kinge8bf8df2011-04-30 10:14:08 +0100137 cl = p;
viresh kumar67b50872012-04-19 04:23:25 +0100138 if (match != best_possible)
139 best_found = match;
viresh kumare4bf5be2010-03-09 11:54:30 +0100140 else
141 break;
Russell King0318e692008-11-09 16:32:46 +0000142 }
143 }
Russell Kinge8bf8df2011-04-30 10:14:08 +0100144 return cl;
Russell King0318e692008-11-09 16:32:46 +0000145}
146
Sascha Hauer05fd8e72009-03-07 12:55:49 +0100147struct clk *clk_get_sys(const char *dev_id, const char *con_id)
Russell King0318e692008-11-09 16:32:46 +0000148{
Russell Kinge8bf8df2011-04-30 10:14:08 +0100149 struct clk_lookup *cl;
Russell King0318e692008-11-09 16:32:46 +0000150
151 mutex_lock(&clocks_mutex);
Russell Kinge8bf8df2011-04-30 10:14:08 +0100152 cl = clk_find(dev_id, con_id);
153 if (cl && !__clk_get(cl->clk))
154 cl = NULL;
Russell King0318e692008-11-09 16:32:46 +0000155 mutex_unlock(&clocks_mutex);
156
Russell Kinge8bf8df2011-04-30 10:14:08 +0100157 return cl ? cl->clk : ERR_PTR(-ENOENT);
Russell King0318e692008-11-09 16:32:46 +0000158}
Sascha Hauer05fd8e72009-03-07 12:55:49 +0100159EXPORT_SYMBOL(clk_get_sys);
160
161struct clk *clk_get(struct device *dev, const char *con_id)
162{
163 const char *dev_id = dev ? dev_name(dev) : NULL;
Grant Likely766e6a42012-04-09 14:50:06 -0500164 struct clk *clk;
165
166 if (dev) {
167 clk = of_clk_get_by_name(dev->of_node, con_id);
Sylwester Nawrocki3a3d2b02013-08-23 17:03:44 +0200168 if (!IS_ERR(clk))
Grant Likely766e6a42012-04-09 14:50:06 -0500169 return clk;
Jean-Francois Moinea34cd462013-11-25 19:47:04 +0100170 if (PTR_ERR(clk) == -EPROBE_DEFER)
171 return clk;
Grant Likely766e6a42012-04-09 14:50:06 -0500172 }
Sascha Hauer05fd8e72009-03-07 12:55:49 +0100173
174 return clk_get_sys(dev_id, con_id);
175}
Russell King0318e692008-11-09 16:32:46 +0000176EXPORT_SYMBOL(clk_get);
177
178void clk_put(struct clk *clk)
179{
180 __clk_put(clk);
181}
182EXPORT_SYMBOL(clk_put);
183
184void clkdev_add(struct clk_lookup *cl)
185{
186 mutex_lock(&clocks_mutex);
187 list_add_tail(&cl->node, &clocks);
188 mutex_unlock(&clocks_mutex);
189}
190EXPORT_SYMBOL(clkdev_add);
191
Russell King0a0300d2010-01-12 12:28:00 +0000192void __init clkdev_add_table(struct clk_lookup *cl, size_t num)
193{
194 mutex_lock(&clocks_mutex);
195 while (num--) {
196 list_add_tail(&cl->node, &clocks);
197 cl++;
198 }
199 mutex_unlock(&clocks_mutex);
200}
201
Russell King0318e692008-11-09 16:32:46 +0000202#define MAX_DEV_ID 20
203#define MAX_CON_ID 16
204
205struct clk_lookup_alloc {
206 struct clk_lookup cl;
207 char dev_id[MAX_DEV_ID];
208 char con_id[MAX_CON_ID];
209};
210
Russell Kinge9d7f402012-05-02 09:30:32 +0100211static struct clk_lookup * __init_refok
212vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt,
213 va_list ap)
Russell King0318e692008-11-09 16:32:46 +0000214{
215 struct clk_lookup_alloc *cla;
216
Jean-Christop PLAGNIOL-VILLARD6d803ba2010-11-17 10:04:33 +0100217 cla = __clkdev_alloc(sizeof(*cla));
Russell King0318e692008-11-09 16:32:46 +0000218 if (!cla)
219 return NULL;
220
221 cla->cl.clk = clk;
222 if (con_id) {
223 strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
224 cla->cl.con_id = cla->con_id;
225 }
226
227 if (dev_fmt) {
Russell King0318e692008-11-09 16:32:46 +0000228 vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
229 cla->cl.dev_id = cla->dev_id;
Russell King0318e692008-11-09 16:32:46 +0000230 }
231
232 return &cla->cl;
233}
Russell Kinge9d7f402012-05-02 09:30:32 +0100234
235struct clk_lookup * __init_refok
236clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)
237{
238 struct clk_lookup *cl;
239 va_list ap;
240
241 va_start(ap, dev_fmt);
242 cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
243 va_end(ap);
244
245 return cl;
246}
Russell King0318e692008-11-09 16:32:46 +0000247EXPORT_SYMBOL(clkdev_alloc);
248
Tony Lindgrenc0683032009-06-03 17:43:14 +0100249int clk_add_alias(const char *alias, const char *alias_dev_name, char *id,
250 struct device *dev)
251{
252 struct clk *r = clk_get(dev, id);
253 struct clk_lookup *l;
254
255 if (IS_ERR(r))
256 return PTR_ERR(r);
257
258 l = clkdev_alloc(r, alias, alias_dev_name);
259 clk_put(r);
260 if (!l)
261 return -ENODEV;
262 clkdev_add(l);
263 return 0;
264}
265EXPORT_SYMBOL(clk_add_alias);
266
Russell King0318e692008-11-09 16:32:46 +0000267/*
268 * clkdev_drop - remove a clock dynamically allocated
269 */
270void clkdev_drop(struct clk_lookup *cl)
271{
272 mutex_lock(&clocks_mutex);
273 list_del(&cl->node);
274 mutex_unlock(&clocks_mutex);
275 kfree(cl);
276}
277EXPORT_SYMBOL(clkdev_drop);
Russell Kinge9d7f402012-05-02 09:30:32 +0100278
279/**
280 * clk_register_clkdev - register one clock lookup for a struct clk
281 * @clk: struct clk to associate with all clk_lookups
282 * @con_id: connection ID string on device
283 * @dev_id: format string describing device name
284 *
285 * con_id or dev_id may be NULL as a wildcard, just as in the rest of
286 * clkdev.
287 *
288 * To make things easier for mass registration, we detect error clks
289 * from a previous clk_register() call, and return the error code for
290 * those. This is to permit this function to be called immediately
291 * after clk_register().
292 */
293int clk_register_clkdev(struct clk *clk, const char *con_id,
294 const char *dev_fmt, ...)
295{
296 struct clk_lookup *cl;
297 va_list ap;
298
299 if (IS_ERR(clk))
300 return PTR_ERR(clk);
301
302 va_start(ap, dev_fmt);
303 cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
304 va_end(ap);
305
306 if (!cl)
307 return -ENOMEM;
308
309 clkdev_add(cl);
310
311 return 0;
312}
313
314/**
315 * clk_register_clkdevs - register a set of clk_lookup for a struct clk
316 * @clk: struct clk to associate with all clk_lookups
317 * @cl: array of clk_lookup structures with con_id and dev_id pre-initialized
318 * @num: number of clk_lookup structures to register
319 *
320 * To make things easier for mass registration, we detect error clks
321 * from a previous clk_register() call, and return the error code for
322 * those. This is to permit this function to be called immediately
323 * after clk_register().
324 */
325int clk_register_clkdevs(struct clk *clk, struct clk_lookup *cl, size_t num)
326{
327 unsigned i;
328
329 if (IS_ERR(clk))
330 return PTR_ERR(clk);
331
332 for (i = 0; i < num; i++, cl++) {
333 cl->clk = clk;
334 clkdev_add(cl);
335 }
336
337 return 0;
338}
339EXPORT_SYMBOL(clk_register_clkdevs);