Loading...
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_found = 0, best_possible = 0;
39
40 if (dev_id)
41 best_possible += 2;
42 if (con_id)
43 best_possible += 1;
44
45 list_for_each_entry(p, &clocks, node) {
46 match = 0;
47 if (p->dev_id) {
48 if (!dev_id || strcmp(p->dev_id, dev_id))
49 continue;
50 match += 2;
51 }
52 if (p->con_id) {
53 if (!con_id || strcmp(p->con_id, con_id))
54 continue;
55 match += 1;
56 }
57
58 if (match > best_found) {
59 cl = p;
60 if (match != best_possible)
61 best_found = match;
62 else
63 break;
64 }
65 }
66 return cl;
67}
68
69struct clk *clk_get_sys(const char *dev_id, const char *con_id)
70{
71 struct clk_lookup *cl;
72
73 mutex_lock(&clocks_mutex);
74 cl = clk_find(dev_id, con_id);
75 if (cl && !__clk_get(cl->clk))
76 cl = NULL;
77 mutex_unlock(&clocks_mutex);
78
79 return cl ? cl->clk : ERR_PTR(-ENOENT);
80}
81EXPORT_SYMBOL(clk_get_sys);
82
83struct clk *clk_get(struct device *dev, const char *con_id)
84{
85 const char *dev_id = dev ? dev_name(dev) : NULL;
86
87 return clk_get_sys(dev_id, con_id);
88}
89EXPORT_SYMBOL(clk_get);
90
91void clk_put(struct clk *clk)
92{
93 __clk_put(clk);
94}
95EXPORT_SYMBOL(clk_put);
96
97static void devm_clk_release(struct device *dev, void *res)
98{
99 clk_put(*(struct clk **)res);
100}
101
102struct clk *devm_clk_get(struct device *dev, const char *id)
103{
104 struct clk **ptr, *clk;
105
106 ptr = devres_alloc(devm_clk_release, sizeof(*ptr), GFP_KERNEL);
107 if (!ptr)
108 return ERR_PTR(-ENOMEM);
109
110 clk = clk_get(dev, id);
111 if (!IS_ERR(clk)) {
112 *ptr = clk;
113 devres_add(dev, ptr);
114 } else {
115 devres_free(ptr);
116 }
117
118 return clk;
119}
120EXPORT_SYMBOL(devm_clk_get);
121
122static int devm_clk_match(struct device *dev, void *res, void *data)
123{
124 struct clk **c = res;
125 if (!c || !*c) {
126 WARN_ON(!c || !*c);
127 return 0;
128 }
129 return *c == data;
130}
131
132void devm_clk_put(struct device *dev, struct clk *clk)
133{
134 int ret;
135
136 ret = devres_destroy(dev, devm_clk_release, devm_clk_match, clk);
137
138 WARN_ON(ret);
139}
140EXPORT_SYMBOL(devm_clk_put);
141
142void clkdev_add(struct clk_lookup *cl)
143{
144 mutex_lock(&clocks_mutex);
145 list_add_tail(&cl->node, &clocks);
146 mutex_unlock(&clocks_mutex);
147}
148EXPORT_SYMBOL(clkdev_add);
149
150void __init clkdev_add_table(struct clk_lookup *cl, size_t num)
151{
152 mutex_lock(&clocks_mutex);
153 while (num--) {
154 list_add_tail(&cl->node, &clocks);
155 cl++;
156 }
157 mutex_unlock(&clocks_mutex);
158}
159
160#define MAX_DEV_ID 20
161#define MAX_CON_ID 16
162
163struct clk_lookup_alloc {
164 struct clk_lookup cl;
165 char dev_id[MAX_DEV_ID];
166 char con_id[MAX_CON_ID];
167};
168
169static struct clk_lookup * __init_refok
170vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt,
171 va_list ap)
172{
173 struct clk_lookup_alloc *cla;
174
175 cla = __clkdev_alloc(sizeof(*cla));
176 if (!cla)
177 return NULL;
178
179 cla->cl.clk = clk;
180 if (con_id) {
181 strlcpy(cla->con_id, con_id, sizeof(cla->con_id));
182 cla->cl.con_id = cla->con_id;
183 }
184
185 if (dev_fmt) {
186 vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
187 cla->cl.dev_id = cla->dev_id;
188 }
189
190 return &cla->cl;
191}
192
193struct clk_lookup * __init_refok
194clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...)
195{
196 struct clk_lookup *cl;
197 va_list ap;
198
199 va_start(ap, dev_fmt);
200 cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
201 va_end(ap);
202
203 return cl;
204}
205EXPORT_SYMBOL(clkdev_alloc);
206
207int clk_add_alias(const char *alias, const char *alias_dev_name, char *id,
208 struct device *dev)
209{
210 struct clk *r = clk_get(dev, id);
211 struct clk_lookup *l;
212
213 if (IS_ERR(r))
214 return PTR_ERR(r);
215
216 l = clkdev_alloc(r, alias, alias_dev_name);
217 clk_put(r);
218 if (!l)
219 return -ENODEV;
220 clkdev_add(l);
221 return 0;
222}
223EXPORT_SYMBOL(clk_add_alias);
224
225/*
226 * clkdev_drop - remove a clock dynamically allocated
227 */
228void clkdev_drop(struct clk_lookup *cl)
229{
230 mutex_lock(&clocks_mutex);
231 list_del(&cl->node);
232 mutex_unlock(&clocks_mutex);
233 kfree(cl);
234}
235EXPORT_SYMBOL(clkdev_drop);
236
237/**
238 * clk_register_clkdev - register one clock lookup for a struct clk
239 * @clk: struct clk to associate with all clk_lookups
240 * @con_id: connection ID string on device
241 * @dev_id: format string describing device name
242 *
243 * con_id or dev_id may be NULL as a wildcard, just as in the rest of
244 * clkdev.
245 *
246 * To make things easier for mass registration, we detect error clks
247 * from a previous clk_register() call, and return the error code for
248 * those. This is to permit this function to be called immediately
249 * after clk_register().
250 */
251int clk_register_clkdev(struct clk *clk, const char *con_id,
252 const char *dev_fmt, ...)
253{
254 struct clk_lookup *cl;
255 va_list ap;
256
257 if (IS_ERR(clk))
258 return PTR_ERR(clk);
259
260 va_start(ap, dev_fmt);
261 cl = vclkdev_alloc(clk, con_id, dev_fmt, ap);
262 va_end(ap);
263
264 if (!cl)
265 return -ENOMEM;
266
267 clkdev_add(cl);
268
269 return 0;
270}
271
272/**
273 * clk_register_clkdevs - register a set of clk_lookup for a struct clk
274 * @clk: struct clk to associate with all clk_lookups
275 * @cl: array of clk_lookup structures with con_id and dev_id pre-initialized
276 * @num: number of clk_lookup structures to register
277 *
278 * To make things easier for mass registration, we detect error clks
279 * from a previous clk_register() call, and return the error code for
280 * those. This is to permit this function to be called immediately
281 * after clk_register().
282 */
283int clk_register_clkdevs(struct clk *clk, struct clk_lookup *cl, size_t num)
284{
285 unsigned i;
286
287 if (IS_ERR(clk))
288 return PTR_ERR(clk);
289
290 for (i = 0; i < num; i++, cl++) {
291 cl->clk = clk;
292 clkdev_add(cl);
293 }
294
295 return 0;
296}
297EXPORT_SYMBOL(clk_register_clkdevs);
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/of.h>
23
24#include "clk.h"
25
26static LIST_HEAD(clocks);
27static DEFINE_MUTEX(clocks_mutex);
28
29#if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK)
30struct 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
44 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();
51 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
104/*
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
111 * order of precedence: dev+con > dev only > con only.
112 */
113static struct clk_lookup *clk_find(const char *dev_id, const char *con_id)
114{
115 struct clk_lookup *p, *cl = NULL;
116 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;
122
123 list_for_each_entry(p, &clocks, node) {
124 match = 0;
125 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 }
135
136 if (match > best_found) {
137 cl = p;
138 if (match != best_possible)
139 best_found = match;
140 else
141 break;
142 }
143 }
144 return cl;
145}
146
147struct clk *clk_get_sys(const char *dev_id, const char *con_id)
148{
149 struct clk_lookup *cl;
150
151 mutex_lock(&clocks_mutex);
152 cl = clk_find(dev_id, con_id);
153 if (cl && !__clk_get(cl->clk))
154 cl = NULL;
155 mutex_unlock(&clocks_mutex);
156
157 return cl ? cl->clk : ERR_PTR(-ENOENT);
158}
159EXPORT_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;
164 struct clk *clk;
165
166 if (dev) {
167 clk = of_clk_get_by_name(dev->of_node, con_id);
168 if (!IS_ERR(clk))
169 return clk;
170 if (PTR_ERR(clk) == -EPROBE_DEFER)
171 return clk;
172 }
173
174 return clk_get_sys(dev_id, con_id);
175}
176EXPORT_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
192void __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
202#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
211static struct clk_lookup * __init_refok
212vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt,
213 va_list ap)
214{
215 struct clk_lookup_alloc *cla;
216
217 cla = __clkdev_alloc(sizeof(*cla));
218 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) {
228 vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap);
229 cla->cl.dev_id = cla->dev_id;
230 }
231
232 return &cla->cl;
233}
234
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}
247EXPORT_SYMBOL(clkdev_alloc);
248
249int 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
267/*
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);
278
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);