1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * drivers/clk/clkdev.c |
4 | * |
5 | * Copyright (C) 2008 Russell King. |
6 | * |
7 | * Helper for the clk API to assist looking up a struct clk. |
8 | */ |
9 | #include <linux/module.h> |
10 | #include <linux/kernel.h> |
11 | #include <linux/device.h> |
12 | #include <linux/list.h> |
13 | #include <linux/errno.h> |
14 | #include <linux/err.h> |
15 | #include <linux/string.h> |
16 | #include <linux/mutex.h> |
17 | #include <linux/clk.h> |
18 | #include <linux/clkdev.h> |
19 | #include <linux/clk-provider.h> |
20 | #include <linux/of.h> |
21 | |
22 | #include "clk.h" |
23 | |
24 | static LIST_HEAD(clocks); |
25 | static DEFINE_MUTEX(clocks_mutex); |
26 | |
27 | /* |
28 | * Find the correct struct clk for the device and connection ID. |
29 | * We do slightly fuzzy matching here: |
30 | * An entry with a NULL ID is assumed to be a wildcard. |
31 | * If an entry has a device ID, it must match |
32 | * If an entry has a connection ID, it must match |
33 | * Then we take the most specific entry - with the following |
34 | * order of precedence: dev+con > dev only > con only. |
35 | */ |
36 | static struct clk_lookup *clk_find(const char *dev_id, const char *con_id) |
37 | { |
38 | struct clk_lookup *p, *cl = NULL; |
39 | int match, best_found = 0, best_possible = 0; |
40 | |
41 | if (dev_id) |
42 | best_possible += 2; |
43 | if (con_id) |
44 | best_possible += 1; |
45 | |
46 | lockdep_assert_held(&clocks_mutex); |
47 | |
48 | list_for_each_entry(p, &clocks, node) { |
49 | match = 0; |
50 | if (p->dev_id) { |
51 | if (!dev_id || strcmp(p->dev_id, dev_id)) |
52 | continue; |
53 | match += 2; |
54 | } |
55 | if (p->con_id) { |
56 | if (!con_id || strcmp(p->con_id, con_id)) |
57 | continue; |
58 | match += 1; |
59 | } |
60 | |
61 | if (match > best_found) { |
62 | cl = p; |
63 | if (match != best_possible) |
64 | best_found = match; |
65 | else |
66 | break; |
67 | } |
68 | } |
69 | return cl; |
70 | } |
71 | |
72 | struct clk_hw *clk_find_hw(const char *dev_id, const char *con_id) |
73 | { |
74 | struct clk_lookup *cl; |
75 | struct clk_hw *hw = ERR_PTR(error: -ENOENT); |
76 | |
77 | mutex_lock(&clocks_mutex); |
78 | cl = clk_find(dev_id, con_id); |
79 | if (cl) |
80 | hw = cl->clk_hw; |
81 | mutex_unlock(lock: &clocks_mutex); |
82 | |
83 | return hw; |
84 | } |
85 | |
86 | static struct clk *__clk_get_sys(struct device *dev, const char *dev_id, |
87 | const char *con_id) |
88 | { |
89 | struct clk_hw *hw = clk_find_hw(dev_id, con_id); |
90 | |
91 | return clk_hw_create_clk(dev, hw, dev_id, con_id); |
92 | } |
93 | |
94 | struct clk *clk_get_sys(const char *dev_id, const char *con_id) |
95 | { |
96 | return __clk_get_sys(NULL, dev_id, con_id); |
97 | } |
98 | EXPORT_SYMBOL(clk_get_sys); |
99 | |
100 | struct clk *clk_get(struct device *dev, const char *con_id) |
101 | { |
102 | const char *dev_id = dev ? dev_name(dev) : NULL; |
103 | struct clk_hw *hw; |
104 | |
105 | if (dev && dev->of_node) { |
106 | hw = of_clk_get_hw(np: dev->of_node, index: 0, con_id); |
107 | if (!IS_ERR(ptr: hw) || PTR_ERR(ptr: hw) == -EPROBE_DEFER) |
108 | return clk_hw_create_clk(dev, hw, dev_id, con_id); |
109 | } |
110 | |
111 | return __clk_get_sys(dev, dev_id, con_id); |
112 | } |
113 | EXPORT_SYMBOL(clk_get); |
114 | |
115 | void clk_put(struct clk *clk) |
116 | { |
117 | __clk_put(clk); |
118 | } |
119 | EXPORT_SYMBOL(clk_put); |
120 | |
121 | static void __clkdev_add(struct clk_lookup *cl) |
122 | { |
123 | mutex_lock(&clocks_mutex); |
124 | list_add_tail(new: &cl->node, head: &clocks); |
125 | mutex_unlock(lock: &clocks_mutex); |
126 | } |
127 | |
128 | void clkdev_add(struct clk_lookup *cl) |
129 | { |
130 | if (!cl->clk_hw) |
131 | cl->clk_hw = __clk_get_hw(clk: cl->clk); |
132 | __clkdev_add(cl); |
133 | } |
134 | EXPORT_SYMBOL(clkdev_add); |
135 | |
136 | void clkdev_add_table(struct clk_lookup *cl, size_t num) |
137 | { |
138 | mutex_lock(&clocks_mutex); |
139 | while (num--) { |
140 | cl->clk_hw = __clk_get_hw(clk: cl->clk); |
141 | list_add_tail(new: &cl->node, head: &clocks); |
142 | cl++; |
143 | } |
144 | mutex_unlock(lock: &clocks_mutex); |
145 | } |
146 | |
147 | #define MAX_DEV_ID 20 |
148 | #define MAX_CON_ID 16 |
149 | |
150 | struct clk_lookup_alloc { |
151 | struct clk_lookup cl; |
152 | char dev_id[MAX_DEV_ID]; |
153 | char con_id[MAX_CON_ID]; |
154 | }; |
155 | |
156 | static struct clk_lookup * __ref |
157 | vclkdev_alloc(struct clk_hw *hw, const char *con_id, const char *dev_fmt, |
158 | va_list ap) |
159 | { |
160 | struct clk_lookup_alloc *cla; |
161 | |
162 | cla = kzalloc(size: sizeof(*cla), GFP_KERNEL); |
163 | if (!cla) |
164 | return NULL; |
165 | |
166 | cla->cl.clk_hw = hw; |
167 | if (con_id) { |
168 | strscpy(p: cla->con_id, q: con_id, size: sizeof(cla->con_id)); |
169 | cla->cl.con_id = cla->con_id; |
170 | } |
171 | |
172 | if (dev_fmt) { |
173 | vscnprintf(buf: cla->dev_id, size: sizeof(cla->dev_id), fmt: dev_fmt, args: ap); |
174 | cla->cl.dev_id = cla->dev_id; |
175 | } |
176 | |
177 | return &cla->cl; |
178 | } |
179 | |
180 | static struct clk_lookup * |
181 | vclkdev_create(struct clk_hw *hw, const char *con_id, const char *dev_fmt, |
182 | va_list ap) |
183 | { |
184 | struct clk_lookup *cl; |
185 | |
186 | cl = vclkdev_alloc(hw, con_id, dev_fmt, ap); |
187 | if (cl) |
188 | __clkdev_add(cl); |
189 | |
190 | return cl; |
191 | } |
192 | |
193 | /** |
194 | * clkdev_create - allocate and add a clkdev lookup structure |
195 | * @clk: struct clk to associate with all clk_lookups |
196 | * @con_id: connection ID string on device |
197 | * @dev_fmt: format string describing device name |
198 | * |
199 | * Returns a clk_lookup structure, which can be later unregistered and |
200 | * freed. |
201 | */ |
202 | struct clk_lookup *clkdev_create(struct clk *clk, const char *con_id, |
203 | const char *dev_fmt, ...) |
204 | { |
205 | struct clk_lookup *cl; |
206 | va_list ap; |
207 | |
208 | va_start(ap, dev_fmt); |
209 | cl = vclkdev_create(hw: __clk_get_hw(clk), con_id, dev_fmt, ap); |
210 | va_end(ap); |
211 | |
212 | return cl; |
213 | } |
214 | EXPORT_SYMBOL_GPL(clkdev_create); |
215 | |
216 | /** |
217 | * clkdev_hw_create - allocate and add a clkdev lookup structure |
218 | * @hw: struct clk_hw to associate with all clk_lookups |
219 | * @con_id: connection ID string on device |
220 | * @dev_fmt: format string describing device name |
221 | * |
222 | * Returns a clk_lookup structure, which can be later unregistered and |
223 | * freed. |
224 | */ |
225 | struct clk_lookup *clkdev_hw_create(struct clk_hw *hw, const char *con_id, |
226 | const char *dev_fmt, ...) |
227 | { |
228 | struct clk_lookup *cl; |
229 | va_list ap; |
230 | |
231 | va_start(ap, dev_fmt); |
232 | cl = vclkdev_create(hw, con_id, dev_fmt, ap); |
233 | va_end(ap); |
234 | |
235 | return cl; |
236 | } |
237 | EXPORT_SYMBOL_GPL(clkdev_hw_create); |
238 | |
239 | int clk_add_alias(const char *alias, const char *alias_dev_name, |
240 | const char *con_id, struct device *dev) |
241 | { |
242 | struct clk *r = clk_get(dev, con_id); |
243 | struct clk_lookup *l; |
244 | |
245 | if (IS_ERR(ptr: r)) |
246 | return PTR_ERR(ptr: r); |
247 | |
248 | l = clkdev_create(r, alias, alias_dev_name ? "%s" : NULL, |
249 | alias_dev_name); |
250 | clk_put(r); |
251 | |
252 | return l ? 0 : -ENODEV; |
253 | } |
254 | EXPORT_SYMBOL(clk_add_alias); |
255 | |
256 | /* |
257 | * clkdev_drop - remove a clock dynamically allocated |
258 | */ |
259 | void clkdev_drop(struct clk_lookup *cl) |
260 | { |
261 | mutex_lock(&clocks_mutex); |
262 | list_del(entry: &cl->node); |
263 | mutex_unlock(lock: &clocks_mutex); |
264 | kfree(objp: cl); |
265 | } |
266 | EXPORT_SYMBOL(clkdev_drop); |
267 | |
268 | static struct clk_lookup *__clk_register_clkdev(struct clk_hw *hw, |
269 | const char *con_id, |
270 | const char *dev_id, ...) |
271 | { |
272 | struct clk_lookup *cl; |
273 | va_list ap; |
274 | |
275 | va_start(ap, dev_id); |
276 | cl = vclkdev_create(hw, con_id, dev_fmt: dev_id, ap); |
277 | va_end(ap); |
278 | |
279 | return cl; |
280 | } |
281 | |
282 | static int do_clk_register_clkdev(struct clk_hw *hw, |
283 | struct clk_lookup **cl, const char *con_id, const char *dev_id) |
284 | { |
285 | if (IS_ERR(ptr: hw)) |
286 | return PTR_ERR(ptr: hw); |
287 | /* |
288 | * Since dev_id can be NULL, and NULL is handled specially, we must |
289 | * pass it as either a NULL format string, or with "%s". |
290 | */ |
291 | if (dev_id) |
292 | *cl = __clk_register_clkdev(hw, con_id, dev_id: "%s" , dev_id); |
293 | else |
294 | *cl = __clk_register_clkdev(hw, con_id, NULL); |
295 | |
296 | return *cl ? 0 : -ENOMEM; |
297 | } |
298 | |
299 | /** |
300 | * clk_register_clkdev - register one clock lookup for a struct clk |
301 | * @clk: struct clk to associate with all clk_lookups |
302 | * @con_id: connection ID string on device |
303 | * @dev_id: string describing device name |
304 | * |
305 | * con_id or dev_id may be NULL as a wildcard, just as in the rest of |
306 | * clkdev. |
307 | * |
308 | * To make things easier for mass registration, we detect error clks |
309 | * from a previous clk_register() call, and return the error code for |
310 | * those. This is to permit this function to be called immediately |
311 | * after clk_register(). |
312 | */ |
313 | int clk_register_clkdev(struct clk *clk, const char *con_id, |
314 | const char *dev_id) |
315 | { |
316 | struct clk_lookup *cl; |
317 | |
318 | if (IS_ERR(ptr: clk)) |
319 | return PTR_ERR(ptr: clk); |
320 | |
321 | return do_clk_register_clkdev(hw: __clk_get_hw(clk), cl: &cl, con_id, |
322 | dev_id); |
323 | } |
324 | EXPORT_SYMBOL(clk_register_clkdev); |
325 | |
326 | /** |
327 | * clk_hw_register_clkdev - register one clock lookup for a struct clk_hw |
328 | * @hw: struct clk_hw to associate with all clk_lookups |
329 | * @con_id: connection ID string on device |
330 | * @dev_id: format string describing device name |
331 | * |
332 | * con_id or dev_id may be NULL as a wildcard, just as in the rest of |
333 | * clkdev. |
334 | * |
335 | * To make things easier for mass registration, we detect error clk_hws |
336 | * from a previous clk_hw_register_*() call, and return the error code for |
337 | * those. This is to permit this function to be called immediately |
338 | * after clk_hw_register_*(). |
339 | */ |
340 | int clk_hw_register_clkdev(struct clk_hw *hw, const char *con_id, |
341 | const char *dev_id) |
342 | { |
343 | struct clk_lookup *cl; |
344 | |
345 | return do_clk_register_clkdev(hw, cl: &cl, con_id, dev_id); |
346 | } |
347 | EXPORT_SYMBOL(clk_hw_register_clkdev); |
348 | |
349 | static void devm_clkdev_release(void *res) |
350 | { |
351 | clkdev_drop(res); |
352 | } |
353 | |
354 | /** |
355 | * devm_clk_hw_register_clkdev - managed clk lookup registration for clk_hw |
356 | * @dev: device this lookup is bound |
357 | * @hw: struct clk_hw 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 clk_hws |
365 | * from a previous clk_hw_register_*() call, and return the error code for |
366 | * those. This is to permit this function to be called immediately |
367 | * after clk_hw_register_*(). |
368 | */ |
369 | int devm_clk_hw_register_clkdev(struct device *dev, struct clk_hw *hw, |
370 | const char *con_id, const char *dev_id) |
371 | { |
372 | struct clk_lookup *cl; |
373 | int rval; |
374 | |
375 | rval = do_clk_register_clkdev(hw, cl: &cl, con_id, dev_id); |
376 | if (rval) |
377 | return rval; |
378 | |
379 | return devm_add_action_or_reset(dev, devm_clkdev_release, cl); |
380 | } |
381 | EXPORT_SYMBOL(devm_clk_hw_register_clkdev); |
382 | |