Commit | Line | Data |
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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 RK |
23 | |
24 | static LIST_HEAD(clocks); | |
25 | static DEFINE_MUTEX(clocks_mutex); | |
26 | ||
137f8a72 | 27 | #if defined(CONFIG_OF) && defined(CONFIG_COMMON_CLK) |
766e6a4e GL |
28 | struct clk *of_clk_get(struct device_node *np, int index) |
29 | { | |
30 | struct of_phandle_args clkspec; | |
31 | struct clk *clk; | |
32 | int rc; | |
33 | ||
34 | if (index < 0) | |
35 | return ERR_PTR(-EINVAL); | |
36 | ||
37 | rc = of_parse_phandle_with_args(np, "clocks", "#clock-cells", index, | |
38 | &clkspec); | |
39 | if (rc) | |
40 | return ERR_PTR(rc); | |
41 | ||
42 | clk = of_clk_get_from_provider(&clkspec); | |
43 | of_node_put(clkspec.np); | |
44 | return clk; | |
45 | } | |
46 | EXPORT_SYMBOL(of_clk_get); | |
47 | ||
48 | /** | |
49 | * of_clk_get_by_name() - Parse and lookup a clock referenced by a device node | |
50 | * @np: pointer to clock consumer node | |
51 | * @name: name of consumer's clock input, or NULL for the first clock reference | |
52 | * | |
53 | * This function parses the clocks and clock-names properties, | |
54 | * and uses them to look up the struct clk from the registered list of clock | |
55 | * providers. | |
56 | */ | |
57 | struct clk *of_clk_get_by_name(struct device_node *np, const char *name) | |
58 | { | |
59 | struct clk *clk = ERR_PTR(-ENOENT); | |
60 | ||
61 | /* Walk up the tree of devices looking for a clock that matches */ | |
62 | while (np) { | |
63 | int index = 0; | |
64 | ||
65 | /* | |
66 | * For named clocks, first look up the name in the | |
67 | * "clock-names" property. If it cannot be found, then | |
68 | * index will be an error code, and of_clk_get() will fail. | |
69 | */ | |
70 | if (name) | |
71 | index = of_property_match_string(np, "clock-names", name); | |
72 | clk = of_clk_get(np, index); | |
73 | if (!IS_ERR(clk)) | |
74 | break; | |
75 | else if (name && index >= 0) { | |
76 | pr_err("ERROR: could not get clock %s:%s(%i)\n", | |
77 | np->full_name, name ? name : "", index); | |
78 | return clk; | |
79 | } | |
80 | ||
81 | /* | |
82 | * No matching clock found on this node. If the parent node | |
83 | * has a "clock-ranges" property, then we can try one of its | |
84 | * clocks. | |
85 | */ | |
86 | np = np->parent; | |
87 | if (np && !of_get_property(np, "clock-ranges", NULL)) | |
88 | break; | |
89 | } | |
90 | ||
91 | return clk; | |
92 | } | |
93 | EXPORT_SYMBOL(of_clk_get_by_name); | |
94 | #endif | |
95 | ||
409dc360 RK |
96 | /* |
97 | * Find the correct struct clk for the device and connection ID. | |
98 | * We do slightly fuzzy matching here: | |
99 | * An entry with a NULL ID is assumed to be a wildcard. | |
100 | * If an entry has a device ID, it must match | |
101 | * If an entry has a connection ID, it must match | |
102 | * Then we take the most specific entry - with the following | |
659431fc | 103 | * order of precedence: dev+con > dev only > con only. |
409dc360 | 104 | */ |
e8bf8df9 | 105 | static struct clk_lookup *clk_find(const char *dev_id, const char *con_id) |
0318e693 | 106 | { |
e8bf8df9 | 107 | struct clk_lookup *p, *cl = NULL; |
67b50871 VK |
108 | int match, best_found = 0, best_possible = 0; |
109 | ||
110 | if (dev_id) | |
111 | best_possible += 2; | |
112 | if (con_id) | |
113 | best_possible += 1; | |
0318e693 RK |
114 | |
115 | list_for_each_entry(p, &clocks, node) { | |
0318e693 | 116 | match = 0; |
409dc360 RK |
117 | if (p->dev_id) { |
118 | if (!dev_id || strcmp(p->dev_id, dev_id)) | |
119 | continue; | |
120 | match += 2; | |
121 | } | |
122 | if (p->con_id) { | |
123 | if (!con_id || strcmp(p->con_id, con_id)) | |
124 | continue; | |
125 | match += 1; | |
126 | } | |
0318e693 | 127 | |
67b50871 | 128 | if (match > best_found) { |
e8bf8df9 | 129 | cl = p; |
67b50871 VK |
130 | if (match != best_possible) |
131 | best_found = match; | |
e4bf5bec | 132 | else |
133 | break; | |
0318e693 RK |
134 | } |
135 | } | |
e8bf8df9 | 136 | return cl; |
0318e693 RK |
137 | } |
138 | ||
05fd8e73 | 139 | struct clk *clk_get_sys(const char *dev_id, const char *con_id) |
0318e693 | 140 | { |
e8bf8df9 | 141 | struct clk_lookup *cl; |
0318e693 RK |
142 | |
143 | mutex_lock(&clocks_mutex); | |
e8bf8df9 RK |
144 | cl = clk_find(dev_id, con_id); |
145 | if (cl && !__clk_get(cl->clk)) | |
146 | cl = NULL; | |
0318e693 RK |
147 | mutex_unlock(&clocks_mutex); |
148 | ||
e8bf8df9 | 149 | return cl ? cl->clk : ERR_PTR(-ENOENT); |
0318e693 | 150 | } |
05fd8e73 SH |
151 | EXPORT_SYMBOL(clk_get_sys); |
152 | ||
153 | struct clk *clk_get(struct device *dev, const char *con_id) | |
154 | { | |
155 | const char *dev_id = dev ? dev_name(dev) : NULL; | |
766e6a4e GL |
156 | struct clk *clk; |
157 | ||
158 | if (dev) { | |
159 | clk = of_clk_get_by_name(dev->of_node, con_id); | |
9f1612d3 | 160 | if (!IS_ERR(clk) && __clk_get(clk)) |
766e6a4e GL |
161 | return clk; |
162 | } | |
05fd8e73 SH |
163 | |
164 | return clk_get_sys(dev_id, con_id); | |
165 | } | |
0318e693 RK |
166 | EXPORT_SYMBOL(clk_get); |
167 | ||
168 | void clk_put(struct clk *clk) | |
169 | { | |
170 | __clk_put(clk); | |
171 | } | |
172 | EXPORT_SYMBOL(clk_put); | |
173 | ||
174 | void clkdev_add(struct clk_lookup *cl) | |
175 | { | |
176 | mutex_lock(&clocks_mutex); | |
177 | list_add_tail(&cl->node, &clocks); | |
178 | mutex_unlock(&clocks_mutex); | |
179 | } | |
180 | EXPORT_SYMBOL(clkdev_add); | |
181 | ||
0a0300dc RK |
182 | void __init clkdev_add_table(struct clk_lookup *cl, size_t num) |
183 | { | |
184 | mutex_lock(&clocks_mutex); | |
185 | while (num--) { | |
186 | list_add_tail(&cl->node, &clocks); | |
187 | cl++; | |
188 | } | |
189 | mutex_unlock(&clocks_mutex); | |
190 | } | |
191 | ||
0318e693 | 192 | #define MAX_DEV_ID 20 |
3c2a0909 | 193 | #define MAX_CON_ID 40 |
0318e693 RK |
194 | |
195 | struct clk_lookup_alloc { | |
196 | struct clk_lookup cl; | |
197 | char dev_id[MAX_DEV_ID]; | |
198 | char con_id[MAX_CON_ID]; | |
199 | }; | |
200 | ||
e9d7f406 RK |
201 | static struct clk_lookup * __init_refok |
202 | vclkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, | |
203 | va_list ap) | |
0318e693 RK |
204 | { |
205 | struct clk_lookup_alloc *cla; | |
206 | ||
6d803ba7 | 207 | cla = __clkdev_alloc(sizeof(*cla)); |
0318e693 RK |
208 | if (!cla) |
209 | return NULL; | |
210 | ||
211 | cla->cl.clk = clk; | |
212 | if (con_id) { | |
213 | strlcpy(cla->con_id, con_id, sizeof(cla->con_id)); | |
214 | cla->cl.con_id = cla->con_id; | |
215 | } | |
216 | ||
217 | if (dev_fmt) { | |
0318e693 RK |
218 | vscnprintf(cla->dev_id, sizeof(cla->dev_id), dev_fmt, ap); |
219 | cla->cl.dev_id = cla->dev_id; | |
0318e693 RK |
220 | } |
221 | ||
222 | return &cla->cl; | |
223 | } | |
e9d7f406 RK |
224 | |
225 | struct clk_lookup * __init_refok | |
226 | clkdev_alloc(struct clk *clk, const char *con_id, const char *dev_fmt, ...) | |
227 | { | |
228 | struct clk_lookup *cl; | |
229 | va_list ap; | |
230 | ||
231 | va_start(ap, dev_fmt); | |
232 | cl = vclkdev_alloc(clk, con_id, dev_fmt, ap); | |
233 | va_end(ap); | |
234 | ||
235 | return cl; | |
236 | } | |
0318e693 RK |
237 | EXPORT_SYMBOL(clkdev_alloc); |
238 | ||
c0683039 TL |
239 | int clk_add_alias(const char *alias, const char *alias_dev_name, char *id, |
240 | struct device *dev) | |
241 | { | |
242 | struct clk *r = clk_get(dev, id); | |
243 | struct clk_lookup *l; | |
244 | ||
245 | if (IS_ERR(r)) | |
246 | return PTR_ERR(r); | |
247 | ||
248 | l = clkdev_alloc(r, alias, alias_dev_name); | |
249 | clk_put(r); | |
250 | if (!l) | |
251 | return -ENODEV; | |
252 | clkdev_add(l); | |
253 | return 0; | |
254 | } | |
255 | EXPORT_SYMBOL(clk_add_alias); | |
256 | ||
0318e693 RK |
257 | /* |
258 | * clkdev_drop - remove a clock dynamically allocated | |
259 | */ | |
260 | void clkdev_drop(struct clk_lookup *cl) | |
261 | { | |
262 | mutex_lock(&clocks_mutex); | |
263 | list_del(&cl->node); | |
264 | mutex_unlock(&clocks_mutex); | |
265 | kfree(cl); | |
266 | } | |
267 | EXPORT_SYMBOL(clkdev_drop); | |
e9d7f406 RK |
268 | |
269 | /** | |
270 | * clk_register_clkdev - register one clock lookup for a struct clk | |
271 | * @clk: struct clk to associate with all clk_lookups | |
272 | * @con_id: connection ID string on device | |
273 | * @dev_id: format string describing device name | |
274 | * | |
275 | * con_id or dev_id may be NULL as a wildcard, just as in the rest of | |
276 | * clkdev. | |
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 | */ | |
283 | int clk_register_clkdev(struct clk *clk, const char *con_id, | |
284 | const char *dev_fmt, ...) | |
285 | { | |
286 | struct clk_lookup *cl; | |
287 | va_list ap; | |
288 | ||
289 | if (IS_ERR(clk)) | |
290 | return PTR_ERR(clk); | |
291 | ||
292 | va_start(ap, dev_fmt); | |
293 | cl = vclkdev_alloc(clk, con_id, dev_fmt, ap); | |
294 | va_end(ap); | |
295 | ||
296 | if (!cl) | |
297 | return -ENOMEM; | |
298 | ||
299 | clkdev_add(cl); | |
300 | ||
301 | return 0; | |
302 | } | |
303 | ||
304 | /** | |
305 | * clk_register_clkdevs - register a set of clk_lookup for a struct clk | |
306 | * @clk: struct clk to associate with all clk_lookups | |
307 | * @cl: array of clk_lookup structures with con_id and dev_id pre-initialized | |
308 | * @num: number of clk_lookup structures to register | |
309 | * | |
310 | * To make things easier for mass registration, we detect error clks | |
311 | * from a previous clk_register() call, and return the error code for | |
312 | * those. This is to permit this function to be called immediately | |
313 | * after clk_register(). | |
314 | */ | |
315 | int clk_register_clkdevs(struct clk *clk, struct clk_lookup *cl, size_t num) | |
316 | { | |
317 | unsigned i; | |
318 | ||
319 | if (IS_ERR(clk)) | |
320 | return PTR_ERR(clk); | |
321 | ||
322 | for (i = 0; i < num; i++, cl++) { | |
323 | cl->clk = clk; | |
324 | clkdev_add(cl); | |
325 | } | |
326 | ||
327 | return 0; | |
328 | } | |
329 | EXPORT_SYMBOL(clk_register_clkdevs); |