1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * Reset Controller framework |
4 | * |
5 | * Copyright 2013 Philipp Zabel, Pengutronix |
6 | */ |
7 | #include <linux/atomic.h> |
8 | #include <linux/cleanup.h> |
9 | #include <linux/device.h> |
10 | #include <linux/err.h> |
11 | #include <linux/export.h> |
12 | #include <linux/kernel.h> |
13 | #include <linux/kref.h> |
14 | #include <linux/gpio/driver.h> |
15 | #include <linux/gpio/machine.h> |
16 | #include <linux/idr.h> |
17 | #include <linux/module.h> |
18 | #include <linux/of.h> |
19 | #include <linux/acpi.h> |
20 | #include <linux/platform_device.h> |
21 | #include <linux/reset.h> |
22 | #include <linux/reset-controller.h> |
23 | #include <linux/slab.h> |
24 | |
25 | static DEFINE_MUTEX(reset_list_mutex); |
26 | static LIST_HEAD(reset_controller_list); |
27 | |
28 | static DEFINE_MUTEX(reset_lookup_mutex); |
29 | static LIST_HEAD(reset_lookup_list); |
30 | |
31 | /* Protects reset_gpio_lookup_list */ |
32 | static DEFINE_MUTEX(reset_gpio_lookup_mutex); |
33 | static LIST_HEAD(reset_gpio_lookup_list); |
34 | static DEFINE_IDA(reset_gpio_ida); |
35 | |
36 | /** |
37 | * struct reset_control - a reset control |
38 | * @rcdev: a pointer to the reset controller device |
39 | * this reset control belongs to |
40 | * @list: list entry for the rcdev's reset controller list |
41 | * @id: ID of the reset controller in the reset |
42 | * controller device |
43 | * @refcnt: Number of gets of this reset_control |
44 | * @acquired: Only one reset_control may be acquired for a given rcdev and id. |
45 | * @shared: Is this a shared (1), or an exclusive (0) reset_control? |
46 | * @array: Is this an array of reset controls (1)? |
47 | * @deassert_count: Number of times this reset line has been deasserted |
48 | * @triggered_count: Number of times this reset line has been reset. Currently |
49 | * only used for shared resets, which means that the value |
50 | * will be either 0 or 1. |
51 | */ |
52 | struct reset_control { |
53 | struct reset_controller_dev *rcdev; |
54 | struct list_head list; |
55 | unsigned int id; |
56 | struct kref refcnt; |
57 | bool acquired; |
58 | bool shared; |
59 | bool array; |
60 | atomic_t deassert_count; |
61 | atomic_t triggered_count; |
62 | }; |
63 | |
64 | /** |
65 | * struct reset_control_array - an array of reset controls |
66 | * @base: reset control for compatibility with reset control API functions |
67 | * @num_rstcs: number of reset controls |
68 | * @rstc: array of reset controls |
69 | */ |
70 | struct reset_control_array { |
71 | struct reset_control base; |
72 | unsigned int num_rstcs; |
73 | struct reset_control *rstc[] __counted_by(num_rstcs); |
74 | }; |
75 | |
76 | /** |
77 | * struct reset_gpio_lookup - lookup key for ad-hoc created reset-gpio devices |
78 | * @of_args: phandle to the reset controller with all the args like GPIO number |
79 | * @list: list entry for the reset_gpio_lookup_list |
80 | */ |
81 | struct reset_gpio_lookup { |
82 | struct of_phandle_args of_args; |
83 | struct list_head list; |
84 | }; |
85 | |
86 | static const char *rcdev_name(struct reset_controller_dev *rcdev) |
87 | { |
88 | if (rcdev->dev) |
89 | return dev_name(dev: rcdev->dev); |
90 | |
91 | if (rcdev->of_node) |
92 | return rcdev->of_node->full_name; |
93 | |
94 | if (rcdev->of_args) |
95 | return rcdev->of_args->np->full_name; |
96 | |
97 | return NULL; |
98 | } |
99 | |
100 | /** |
101 | * of_reset_simple_xlate - translate reset_spec to the reset line number |
102 | * @rcdev: a pointer to the reset controller device |
103 | * @reset_spec: reset line specifier as found in the device tree |
104 | * |
105 | * This static translation function is used by default if of_xlate in |
106 | * :c:type:`reset_controller_dev` is not set. It is useful for all reset |
107 | * controllers with 1:1 mapping, where reset lines can be indexed by number |
108 | * without gaps. |
109 | */ |
110 | static int of_reset_simple_xlate(struct reset_controller_dev *rcdev, |
111 | const struct of_phandle_args *reset_spec) |
112 | { |
113 | if (reset_spec->args[0] >= rcdev->nr_resets) |
114 | return -EINVAL; |
115 | |
116 | return reset_spec->args[0]; |
117 | } |
118 | |
119 | /** |
120 | * reset_controller_register - register a reset controller device |
121 | * @rcdev: a pointer to the initialized reset controller device |
122 | */ |
123 | int reset_controller_register(struct reset_controller_dev *rcdev) |
124 | { |
125 | if (rcdev->of_node && rcdev->of_args) |
126 | return -EINVAL; |
127 | |
128 | if (!rcdev->of_xlate) { |
129 | rcdev->of_reset_n_cells = 1; |
130 | rcdev->of_xlate = of_reset_simple_xlate; |
131 | } |
132 | |
133 | INIT_LIST_HEAD(list: &rcdev->reset_control_head); |
134 | |
135 | mutex_lock(&reset_list_mutex); |
136 | list_add(new: &rcdev->list, head: &reset_controller_list); |
137 | mutex_unlock(lock: &reset_list_mutex); |
138 | |
139 | return 0; |
140 | } |
141 | EXPORT_SYMBOL_GPL(reset_controller_register); |
142 | |
143 | /** |
144 | * reset_controller_unregister - unregister a reset controller device |
145 | * @rcdev: a pointer to the reset controller device |
146 | */ |
147 | void reset_controller_unregister(struct reset_controller_dev *rcdev) |
148 | { |
149 | mutex_lock(&reset_list_mutex); |
150 | list_del(entry: &rcdev->list); |
151 | mutex_unlock(lock: &reset_list_mutex); |
152 | } |
153 | EXPORT_SYMBOL_GPL(reset_controller_unregister); |
154 | |
155 | static void devm_reset_controller_release(struct device *dev, void *res) |
156 | { |
157 | reset_controller_unregister(*(struct reset_controller_dev **)res); |
158 | } |
159 | |
160 | /** |
161 | * devm_reset_controller_register - resource managed reset_controller_register() |
162 | * @dev: device that is registering this reset controller |
163 | * @rcdev: a pointer to the initialized reset controller device |
164 | * |
165 | * Managed reset_controller_register(). For reset controllers registered by |
166 | * this function, reset_controller_unregister() is automatically called on |
167 | * driver detach. See reset_controller_register() for more information. |
168 | */ |
169 | int devm_reset_controller_register(struct device *dev, |
170 | struct reset_controller_dev *rcdev) |
171 | { |
172 | struct reset_controller_dev **rcdevp; |
173 | int ret; |
174 | |
175 | rcdevp = devres_alloc(devm_reset_controller_release, sizeof(*rcdevp), |
176 | GFP_KERNEL); |
177 | if (!rcdevp) |
178 | return -ENOMEM; |
179 | |
180 | ret = reset_controller_register(rcdev); |
181 | if (ret) { |
182 | devres_free(res: rcdevp); |
183 | return ret; |
184 | } |
185 | |
186 | *rcdevp = rcdev; |
187 | devres_add(dev, res: rcdevp); |
188 | |
189 | return ret; |
190 | } |
191 | EXPORT_SYMBOL_GPL(devm_reset_controller_register); |
192 | |
193 | /** |
194 | * reset_controller_add_lookup - register a set of lookup entries |
195 | * @lookup: array of reset lookup entries |
196 | * @num_entries: number of entries in the lookup array |
197 | */ |
198 | void reset_controller_add_lookup(struct reset_control_lookup *lookup, |
199 | unsigned int num_entries) |
200 | { |
201 | struct reset_control_lookup *entry; |
202 | unsigned int i; |
203 | |
204 | mutex_lock(&reset_lookup_mutex); |
205 | for (i = 0; i < num_entries; i++) { |
206 | entry = &lookup[i]; |
207 | |
208 | if (!entry->dev_id || !entry->provider) { |
209 | pr_warn("%s(): reset lookup entry badly specified, skipping\n" , |
210 | __func__); |
211 | continue; |
212 | } |
213 | |
214 | list_add_tail(new: &entry->list, head: &reset_lookup_list); |
215 | } |
216 | mutex_unlock(lock: &reset_lookup_mutex); |
217 | } |
218 | EXPORT_SYMBOL_GPL(reset_controller_add_lookup); |
219 | |
220 | static inline struct reset_control_array * |
221 | rstc_to_array(struct reset_control *rstc) { |
222 | return container_of(rstc, struct reset_control_array, base); |
223 | } |
224 | |
225 | static int reset_control_array_reset(struct reset_control_array *resets) |
226 | { |
227 | int ret, i; |
228 | |
229 | for (i = 0; i < resets->num_rstcs; i++) { |
230 | ret = reset_control_reset(rstc: resets->rstc[i]); |
231 | if (ret) |
232 | return ret; |
233 | } |
234 | |
235 | return 0; |
236 | } |
237 | |
238 | static int reset_control_array_rearm(struct reset_control_array *resets) |
239 | { |
240 | struct reset_control *rstc; |
241 | int i; |
242 | |
243 | for (i = 0; i < resets->num_rstcs; i++) { |
244 | rstc = resets->rstc[i]; |
245 | |
246 | if (!rstc) |
247 | continue; |
248 | |
249 | if (WARN_ON(IS_ERR(rstc))) |
250 | return -EINVAL; |
251 | |
252 | if (rstc->shared) { |
253 | if (WARN_ON(atomic_read(&rstc->deassert_count) != 0)) |
254 | return -EINVAL; |
255 | } else { |
256 | if (!rstc->acquired) |
257 | return -EPERM; |
258 | } |
259 | } |
260 | |
261 | for (i = 0; i < resets->num_rstcs; i++) { |
262 | rstc = resets->rstc[i]; |
263 | |
264 | if (rstc && rstc->shared) |
265 | WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0); |
266 | } |
267 | |
268 | return 0; |
269 | } |
270 | |
271 | static int reset_control_array_assert(struct reset_control_array *resets) |
272 | { |
273 | int ret, i; |
274 | |
275 | for (i = 0; i < resets->num_rstcs; i++) { |
276 | ret = reset_control_assert(rstc: resets->rstc[i]); |
277 | if (ret) |
278 | goto err; |
279 | } |
280 | |
281 | return 0; |
282 | |
283 | err: |
284 | while (i--) |
285 | reset_control_deassert(rstc: resets->rstc[i]); |
286 | return ret; |
287 | } |
288 | |
289 | static int reset_control_array_deassert(struct reset_control_array *resets) |
290 | { |
291 | int ret, i; |
292 | |
293 | for (i = 0; i < resets->num_rstcs; i++) { |
294 | ret = reset_control_deassert(rstc: resets->rstc[i]); |
295 | if (ret) |
296 | goto err; |
297 | } |
298 | |
299 | return 0; |
300 | |
301 | err: |
302 | while (i--) |
303 | reset_control_assert(rstc: resets->rstc[i]); |
304 | return ret; |
305 | } |
306 | |
307 | static int reset_control_array_acquire(struct reset_control_array *resets) |
308 | { |
309 | unsigned int i; |
310 | int err; |
311 | |
312 | for (i = 0; i < resets->num_rstcs; i++) { |
313 | err = reset_control_acquire(rstc: resets->rstc[i]); |
314 | if (err < 0) |
315 | goto release; |
316 | } |
317 | |
318 | return 0; |
319 | |
320 | release: |
321 | while (i--) |
322 | reset_control_release(rstc: resets->rstc[i]); |
323 | |
324 | return err; |
325 | } |
326 | |
327 | static void reset_control_array_release(struct reset_control_array *resets) |
328 | { |
329 | unsigned int i; |
330 | |
331 | for (i = 0; i < resets->num_rstcs; i++) |
332 | reset_control_release(rstc: resets->rstc[i]); |
333 | } |
334 | |
335 | static inline bool reset_control_is_array(struct reset_control *rstc) |
336 | { |
337 | return rstc->array; |
338 | } |
339 | |
340 | /** |
341 | * reset_control_reset - reset the controlled device |
342 | * @rstc: reset controller |
343 | * |
344 | * On a shared reset line the actual reset pulse is only triggered once for the |
345 | * lifetime of the reset_control instance: for all but the first caller this is |
346 | * a no-op. |
347 | * Consumers must not use reset_control_(de)assert on shared reset lines when |
348 | * reset_control_reset has been used. |
349 | * |
350 | * If rstc is NULL it is an optional reset and the function will just |
351 | * return 0. |
352 | */ |
353 | int reset_control_reset(struct reset_control *rstc) |
354 | { |
355 | int ret; |
356 | |
357 | if (!rstc) |
358 | return 0; |
359 | |
360 | if (WARN_ON(IS_ERR(rstc))) |
361 | return -EINVAL; |
362 | |
363 | if (reset_control_is_array(rstc)) |
364 | return reset_control_array_reset(resets: rstc_to_array(rstc)); |
365 | |
366 | if (!rstc->rcdev->ops->reset) |
367 | return -ENOTSUPP; |
368 | |
369 | if (rstc->shared) { |
370 | if (WARN_ON(atomic_read(&rstc->deassert_count) != 0)) |
371 | return -EINVAL; |
372 | |
373 | if (atomic_inc_return(v: &rstc->triggered_count) != 1) |
374 | return 0; |
375 | } else { |
376 | if (!rstc->acquired) |
377 | return -EPERM; |
378 | } |
379 | |
380 | ret = rstc->rcdev->ops->reset(rstc->rcdev, rstc->id); |
381 | if (rstc->shared && ret) |
382 | atomic_dec(v: &rstc->triggered_count); |
383 | |
384 | return ret; |
385 | } |
386 | EXPORT_SYMBOL_GPL(reset_control_reset); |
387 | |
388 | /** |
389 | * reset_control_bulk_reset - reset the controlled devices in order |
390 | * @num_rstcs: number of entries in rstcs array |
391 | * @rstcs: array of struct reset_control_bulk_data with reset controls set |
392 | * |
393 | * Issue a reset on all provided reset controls, in order. |
394 | * |
395 | * See also: reset_control_reset() |
396 | */ |
397 | int reset_control_bulk_reset(int num_rstcs, |
398 | struct reset_control_bulk_data *rstcs) |
399 | { |
400 | int ret, i; |
401 | |
402 | for (i = 0; i < num_rstcs; i++) { |
403 | ret = reset_control_reset(rstcs[i].rstc); |
404 | if (ret) |
405 | return ret; |
406 | } |
407 | |
408 | return 0; |
409 | } |
410 | EXPORT_SYMBOL_GPL(reset_control_bulk_reset); |
411 | |
412 | /** |
413 | * reset_control_rearm - allow shared reset line to be re-triggered" |
414 | * @rstc: reset controller |
415 | * |
416 | * On a shared reset line the actual reset pulse is only triggered once for the |
417 | * lifetime of the reset_control instance, except if this call is used. |
418 | * |
419 | * Calls to this function must be balanced with calls to reset_control_reset, |
420 | * a warning is thrown in case triggered_count ever dips below 0. |
421 | * |
422 | * Consumers must not use reset_control_(de)assert on shared reset lines when |
423 | * reset_control_reset or reset_control_rearm have been used. |
424 | * |
425 | * If rstc is NULL the function will just return 0. |
426 | */ |
427 | int reset_control_rearm(struct reset_control *rstc) |
428 | { |
429 | if (!rstc) |
430 | return 0; |
431 | |
432 | if (WARN_ON(IS_ERR(rstc))) |
433 | return -EINVAL; |
434 | |
435 | if (reset_control_is_array(rstc)) |
436 | return reset_control_array_rearm(resets: rstc_to_array(rstc)); |
437 | |
438 | if (rstc->shared) { |
439 | if (WARN_ON(atomic_read(&rstc->deassert_count) != 0)) |
440 | return -EINVAL; |
441 | |
442 | WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0); |
443 | } else { |
444 | if (!rstc->acquired) |
445 | return -EPERM; |
446 | } |
447 | |
448 | return 0; |
449 | } |
450 | EXPORT_SYMBOL_GPL(reset_control_rearm); |
451 | |
452 | /** |
453 | * reset_control_assert - asserts the reset line |
454 | * @rstc: reset controller |
455 | * |
456 | * Calling this on an exclusive reset controller guarantees that the reset |
457 | * will be asserted. When called on a shared reset controller the line may |
458 | * still be deasserted, as long as other users keep it so. |
459 | * |
460 | * For shared reset controls a driver cannot expect the hw's registers and |
461 | * internal state to be reset, but must be prepared for this to happen. |
462 | * Consumers must not use reset_control_reset on shared reset lines when |
463 | * reset_control_(de)assert has been used. |
464 | * |
465 | * If rstc is NULL it is an optional reset and the function will just |
466 | * return 0. |
467 | */ |
468 | int reset_control_assert(struct reset_control *rstc) |
469 | { |
470 | if (!rstc) |
471 | return 0; |
472 | |
473 | if (WARN_ON(IS_ERR(rstc))) |
474 | return -EINVAL; |
475 | |
476 | if (reset_control_is_array(rstc)) |
477 | return reset_control_array_assert(resets: rstc_to_array(rstc)); |
478 | |
479 | if (rstc->shared) { |
480 | if (WARN_ON(atomic_read(&rstc->triggered_count) != 0)) |
481 | return -EINVAL; |
482 | |
483 | if (WARN_ON(atomic_read(&rstc->deassert_count) == 0)) |
484 | return -EINVAL; |
485 | |
486 | if (atomic_dec_return(v: &rstc->deassert_count) != 0) |
487 | return 0; |
488 | |
489 | /* |
490 | * Shared reset controls allow the reset line to be in any state |
491 | * after this call, so doing nothing is a valid option. |
492 | */ |
493 | if (!rstc->rcdev->ops->assert) |
494 | return 0; |
495 | } else { |
496 | /* |
497 | * If the reset controller does not implement .assert(), there |
498 | * is no way to guarantee that the reset line is asserted after |
499 | * this call. |
500 | */ |
501 | if (!rstc->rcdev->ops->assert) |
502 | return -ENOTSUPP; |
503 | |
504 | if (!rstc->acquired) { |
505 | WARN(1, "reset %s (ID: %u) is not acquired\n" , |
506 | rcdev_name(rstc->rcdev), rstc->id); |
507 | return -EPERM; |
508 | } |
509 | } |
510 | |
511 | return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id); |
512 | } |
513 | EXPORT_SYMBOL_GPL(reset_control_assert); |
514 | |
515 | /** |
516 | * reset_control_bulk_assert - asserts the reset lines in order |
517 | * @num_rstcs: number of entries in rstcs array |
518 | * @rstcs: array of struct reset_control_bulk_data with reset controls set |
519 | * |
520 | * Assert the reset lines for all provided reset controls, in order. |
521 | * If an assertion fails, already asserted resets are deasserted again. |
522 | * |
523 | * See also: reset_control_assert() |
524 | */ |
525 | int reset_control_bulk_assert(int num_rstcs, |
526 | struct reset_control_bulk_data *rstcs) |
527 | { |
528 | int ret, i; |
529 | |
530 | for (i = 0; i < num_rstcs; i++) { |
531 | ret = reset_control_assert(rstcs[i].rstc); |
532 | if (ret) |
533 | goto err; |
534 | } |
535 | |
536 | return 0; |
537 | |
538 | err: |
539 | while (i--) |
540 | reset_control_deassert(rstc: rstcs[i].rstc); |
541 | return ret; |
542 | } |
543 | EXPORT_SYMBOL_GPL(reset_control_bulk_assert); |
544 | |
545 | /** |
546 | * reset_control_deassert - deasserts the reset line |
547 | * @rstc: reset controller |
548 | * |
549 | * After calling this function, the reset is guaranteed to be deasserted. |
550 | * Consumers must not use reset_control_reset on shared reset lines when |
551 | * reset_control_(de)assert has been used. |
552 | * |
553 | * If rstc is NULL it is an optional reset and the function will just |
554 | * return 0. |
555 | */ |
556 | int reset_control_deassert(struct reset_control *rstc) |
557 | { |
558 | if (!rstc) |
559 | return 0; |
560 | |
561 | if (WARN_ON(IS_ERR(rstc))) |
562 | return -EINVAL; |
563 | |
564 | if (reset_control_is_array(rstc)) |
565 | return reset_control_array_deassert(resets: rstc_to_array(rstc)); |
566 | |
567 | if (rstc->shared) { |
568 | if (WARN_ON(atomic_read(&rstc->triggered_count) != 0)) |
569 | return -EINVAL; |
570 | |
571 | if (atomic_inc_return(v: &rstc->deassert_count) != 1) |
572 | return 0; |
573 | } else { |
574 | if (!rstc->acquired) { |
575 | WARN(1, "reset %s (ID: %u) is not acquired\n" , |
576 | rcdev_name(rstc->rcdev), rstc->id); |
577 | return -EPERM; |
578 | } |
579 | } |
580 | |
581 | /* |
582 | * If the reset controller does not implement .deassert(), we assume |
583 | * that it handles self-deasserting reset lines via .reset(). In that |
584 | * case, the reset lines are deasserted by default. If that is not the |
585 | * case, the reset controller driver should implement .deassert() and |
586 | * return -ENOTSUPP. |
587 | */ |
588 | if (!rstc->rcdev->ops->deassert) |
589 | return 0; |
590 | |
591 | return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id); |
592 | } |
593 | EXPORT_SYMBOL_GPL(reset_control_deassert); |
594 | |
595 | /** |
596 | * reset_control_bulk_deassert - deasserts the reset lines in reverse order |
597 | * @num_rstcs: number of entries in rstcs array |
598 | * @rstcs: array of struct reset_control_bulk_data with reset controls set |
599 | * |
600 | * Deassert the reset lines for all provided reset controls, in reverse order. |
601 | * If a deassertion fails, already deasserted resets are asserted again. |
602 | * |
603 | * See also: reset_control_deassert() |
604 | */ |
605 | int reset_control_bulk_deassert(int num_rstcs, |
606 | struct reset_control_bulk_data *rstcs) |
607 | { |
608 | int ret, i; |
609 | |
610 | for (i = num_rstcs - 1; i >= 0; i--) { |
611 | ret = reset_control_deassert(rstcs[i].rstc); |
612 | if (ret) |
613 | goto err; |
614 | } |
615 | |
616 | return 0; |
617 | |
618 | err: |
619 | while (i < num_rstcs) |
620 | reset_control_assert(rstcs[i++].rstc); |
621 | return ret; |
622 | } |
623 | EXPORT_SYMBOL_GPL(reset_control_bulk_deassert); |
624 | |
625 | /** |
626 | * reset_control_status - returns a negative errno if not supported, a |
627 | * positive value if the reset line is asserted, or zero if the reset |
628 | * line is not asserted or if the desc is NULL (optional reset). |
629 | * @rstc: reset controller |
630 | */ |
631 | int reset_control_status(struct reset_control *rstc) |
632 | { |
633 | if (!rstc) |
634 | return 0; |
635 | |
636 | if (WARN_ON(IS_ERR(rstc)) || reset_control_is_array(rstc)) |
637 | return -EINVAL; |
638 | |
639 | if (rstc->rcdev->ops->status) |
640 | return rstc->rcdev->ops->status(rstc->rcdev, rstc->id); |
641 | |
642 | return -ENOTSUPP; |
643 | } |
644 | EXPORT_SYMBOL_GPL(reset_control_status); |
645 | |
646 | /** |
647 | * reset_control_acquire() - acquires a reset control for exclusive use |
648 | * @rstc: reset control |
649 | * |
650 | * This is used to explicitly acquire a reset control for exclusive use. Note |
651 | * that exclusive resets are requested as acquired by default. In order for a |
652 | * second consumer to be able to control the reset, the first consumer has to |
653 | * release it first. Typically the easiest way to achieve this is to call the |
654 | * reset_control_get_exclusive_released() to obtain an instance of the reset |
655 | * control. Such reset controls are not acquired by default. |
656 | * |
657 | * Consumers implementing shared access to an exclusive reset need to follow |
658 | * a specific protocol in order to work together. Before consumers can change |
659 | * a reset they must acquire exclusive access using reset_control_acquire(). |
660 | * After they are done operating the reset, they must release exclusive access |
661 | * with a call to reset_control_release(). Consumers are not granted exclusive |
662 | * access to the reset as long as another consumer hasn't released a reset. |
663 | * |
664 | * See also: reset_control_release() |
665 | */ |
666 | int reset_control_acquire(struct reset_control *rstc) |
667 | { |
668 | struct reset_control *rc; |
669 | |
670 | if (!rstc) |
671 | return 0; |
672 | |
673 | if (WARN_ON(IS_ERR(rstc))) |
674 | return -EINVAL; |
675 | |
676 | if (reset_control_is_array(rstc)) |
677 | return reset_control_array_acquire(resets: rstc_to_array(rstc)); |
678 | |
679 | mutex_lock(&reset_list_mutex); |
680 | |
681 | if (rstc->acquired) { |
682 | mutex_unlock(lock: &reset_list_mutex); |
683 | return 0; |
684 | } |
685 | |
686 | list_for_each_entry(rc, &rstc->rcdev->reset_control_head, list) { |
687 | if (rstc != rc && rstc->id == rc->id) { |
688 | if (rc->acquired) { |
689 | mutex_unlock(lock: &reset_list_mutex); |
690 | return -EBUSY; |
691 | } |
692 | } |
693 | } |
694 | |
695 | rstc->acquired = true; |
696 | |
697 | mutex_unlock(lock: &reset_list_mutex); |
698 | return 0; |
699 | } |
700 | EXPORT_SYMBOL_GPL(reset_control_acquire); |
701 | |
702 | /** |
703 | * reset_control_bulk_acquire - acquires reset controls for exclusive use |
704 | * @num_rstcs: number of entries in rstcs array |
705 | * @rstcs: array of struct reset_control_bulk_data with reset controls set |
706 | * |
707 | * This is used to explicitly acquire reset controls requested with |
708 | * reset_control_bulk_get_exclusive_release() for temporary exclusive use. |
709 | * |
710 | * See also: reset_control_acquire(), reset_control_bulk_release() |
711 | */ |
712 | int reset_control_bulk_acquire(int num_rstcs, |
713 | struct reset_control_bulk_data *rstcs) |
714 | { |
715 | int ret, i; |
716 | |
717 | for (i = 0; i < num_rstcs; i++) { |
718 | ret = reset_control_acquire(rstcs[i].rstc); |
719 | if (ret) |
720 | goto err; |
721 | } |
722 | |
723 | return 0; |
724 | |
725 | err: |
726 | while (i--) |
727 | reset_control_release(rstc: rstcs[i].rstc); |
728 | return ret; |
729 | } |
730 | EXPORT_SYMBOL_GPL(reset_control_bulk_acquire); |
731 | |
732 | /** |
733 | * reset_control_release() - releases exclusive access to a reset control |
734 | * @rstc: reset control |
735 | * |
736 | * Releases exclusive access right to a reset control previously obtained by a |
737 | * call to reset_control_acquire(). Until a consumer calls this function, no |
738 | * other consumers will be granted exclusive access. |
739 | * |
740 | * See also: reset_control_acquire() |
741 | */ |
742 | void reset_control_release(struct reset_control *rstc) |
743 | { |
744 | if (!rstc || WARN_ON(IS_ERR(rstc))) |
745 | return; |
746 | |
747 | if (reset_control_is_array(rstc)) |
748 | reset_control_array_release(resets: rstc_to_array(rstc)); |
749 | else |
750 | rstc->acquired = false; |
751 | } |
752 | EXPORT_SYMBOL_GPL(reset_control_release); |
753 | |
754 | /** |
755 | * reset_control_bulk_release() - releases exclusive access to reset controls |
756 | * @num_rstcs: number of entries in rstcs array |
757 | * @rstcs: array of struct reset_control_bulk_data with reset controls set |
758 | * |
759 | * Releases exclusive access right to reset controls previously obtained by a |
760 | * call to reset_control_bulk_acquire(). |
761 | * |
762 | * See also: reset_control_release(), reset_control_bulk_acquire() |
763 | */ |
764 | void reset_control_bulk_release(int num_rstcs, |
765 | struct reset_control_bulk_data *rstcs) |
766 | { |
767 | int i; |
768 | |
769 | for (i = 0; i < num_rstcs; i++) |
770 | reset_control_release(rstcs[i].rstc); |
771 | } |
772 | EXPORT_SYMBOL_GPL(reset_control_bulk_release); |
773 | |
774 | static struct reset_control * |
775 | __reset_control_get_internal(struct reset_controller_dev *rcdev, |
776 | unsigned int index, bool shared, bool acquired) |
777 | { |
778 | struct reset_control *rstc; |
779 | |
780 | lockdep_assert_held(&reset_list_mutex); |
781 | |
782 | list_for_each_entry(rstc, &rcdev->reset_control_head, list) { |
783 | if (rstc->id == index) { |
784 | /* |
785 | * Allow creating a secondary exclusive reset_control |
786 | * that is initially not acquired for an already |
787 | * controlled reset line. |
788 | */ |
789 | if (!rstc->shared && !shared && !acquired) |
790 | break; |
791 | |
792 | if (WARN_ON(!rstc->shared || !shared)) |
793 | return ERR_PTR(error: -EBUSY); |
794 | |
795 | kref_get(kref: &rstc->refcnt); |
796 | return rstc; |
797 | } |
798 | } |
799 | |
800 | rstc = kzalloc(size: sizeof(*rstc), GFP_KERNEL); |
801 | if (!rstc) |
802 | return ERR_PTR(error: -ENOMEM); |
803 | |
804 | if (!try_module_get(module: rcdev->owner)) { |
805 | kfree(objp: rstc); |
806 | return ERR_PTR(error: -ENODEV); |
807 | } |
808 | |
809 | rstc->rcdev = rcdev; |
810 | list_add(new: &rstc->list, head: &rcdev->reset_control_head); |
811 | rstc->id = index; |
812 | kref_init(kref: &rstc->refcnt); |
813 | rstc->acquired = acquired; |
814 | rstc->shared = shared; |
815 | |
816 | return rstc; |
817 | } |
818 | |
819 | static void __reset_control_release(struct kref *kref) |
820 | { |
821 | struct reset_control *rstc = container_of(kref, struct reset_control, |
822 | refcnt); |
823 | |
824 | lockdep_assert_held(&reset_list_mutex); |
825 | |
826 | module_put(module: rstc->rcdev->owner); |
827 | |
828 | list_del(entry: &rstc->list); |
829 | kfree(objp: rstc); |
830 | } |
831 | |
832 | static void __reset_control_put_internal(struct reset_control *rstc) |
833 | { |
834 | lockdep_assert_held(&reset_list_mutex); |
835 | |
836 | if (IS_ERR_OR_NULL(ptr: rstc)) |
837 | return; |
838 | |
839 | kref_put(kref: &rstc->refcnt, release: __reset_control_release); |
840 | } |
841 | |
842 | static int __reset_add_reset_gpio_lookup(int id, struct device_node *np, |
843 | unsigned int gpio, |
844 | unsigned int of_flags) |
845 | { |
846 | const struct fwnode_handle *fwnode = of_fwnode_handle(np); |
847 | unsigned int lookup_flags; |
848 | const char *label_tmp; |
849 | |
850 | /* |
851 | * Later we map GPIO flags between OF and Linux, however not all |
852 | * constants from include/dt-bindings/gpio/gpio.h and |
853 | * include/linux/gpio/machine.h match each other. |
854 | */ |
855 | if (of_flags > GPIO_ACTIVE_LOW) { |
856 | pr_err("reset-gpio code does not support GPIO flags %u for GPIO %u\n" , |
857 | of_flags, gpio); |
858 | return -EINVAL; |
859 | } |
860 | |
861 | struct gpio_device *gdev __free(gpio_device_put) = gpio_device_find_by_fwnode(fwnode); |
862 | if (!gdev) |
863 | return -EPROBE_DEFER; |
864 | |
865 | label_tmp = gpio_device_get_label(gdev); |
866 | if (!label_tmp) |
867 | return -EINVAL; |
868 | |
869 | char *label __free(kfree) = kstrdup(s: label_tmp, GFP_KERNEL); |
870 | if (!label) |
871 | return -ENOMEM; |
872 | |
873 | /* Size: one lookup entry plus sentinel */ |
874 | struct gpiod_lookup_table *lookup __free(kfree) = kzalloc(struct_size(lookup, table, 2), |
875 | GFP_KERNEL); |
876 | if (!lookup) |
877 | return -ENOMEM; |
878 | |
879 | lookup->dev_id = kasprintf(GFP_KERNEL, fmt: "reset-gpio.%d" , id); |
880 | if (!lookup->dev_id) |
881 | return -ENOMEM; |
882 | |
883 | lookup_flags = GPIO_PERSISTENT; |
884 | lookup_flags |= of_flags & GPIO_ACTIVE_LOW; |
885 | lookup->table[0] = GPIO_LOOKUP(no_free_ptr(label), gpio, "reset" , |
886 | lookup_flags); |
887 | |
888 | /* Not freed on success, because it is persisent subsystem data. */ |
889 | gpiod_add_lookup_table(no_free_ptr(lookup)); |
890 | |
891 | return 0; |
892 | } |
893 | |
894 | /* |
895 | * @args: phandle to the GPIO provider with all the args like GPIO number |
896 | */ |
897 | static int __reset_add_reset_gpio_device(const struct of_phandle_args *args) |
898 | { |
899 | struct reset_gpio_lookup *rgpio_dev; |
900 | struct platform_device *pdev; |
901 | int id, ret; |
902 | |
903 | /* |
904 | * Currently only #gpio-cells=2 is supported with the meaning of: |
905 | * args[0]: GPIO number |
906 | * args[1]: GPIO flags |
907 | * TODO: Handle other cases. |
908 | */ |
909 | if (args->args_count != 2) |
910 | return -ENOENT; |
911 | |
912 | /* |
913 | * Registering reset-gpio device might cause immediate |
914 | * bind, resulting in its probe() registering new reset controller thus |
915 | * taking reset_list_mutex lock via reset_controller_register(). |
916 | */ |
917 | lockdep_assert_not_held(&reset_list_mutex); |
918 | |
919 | mutex_lock(&reset_gpio_lookup_mutex); |
920 | |
921 | list_for_each_entry(rgpio_dev, &reset_gpio_lookup_list, list) { |
922 | if (args->np == rgpio_dev->of_args.np) { |
923 | if (of_phandle_args_equal(a1: args, a2: &rgpio_dev->of_args)) |
924 | goto out; /* Already on the list, done */ |
925 | } |
926 | } |
927 | |
928 | id = ida_alloc(ida: &reset_gpio_ida, GFP_KERNEL); |
929 | if (id < 0) { |
930 | ret = id; |
931 | goto err_unlock; |
932 | } |
933 | |
934 | /* Not freed on success, because it is persisent subsystem data. */ |
935 | rgpio_dev = kzalloc(size: sizeof(*rgpio_dev), GFP_KERNEL); |
936 | if (!rgpio_dev) { |
937 | ret = -ENOMEM; |
938 | goto err_ida_free; |
939 | } |
940 | |
941 | ret = __reset_add_reset_gpio_lookup(id, np: args->np, gpio: args->args[0], |
942 | of_flags: args->args[1]); |
943 | if (ret < 0) |
944 | goto err_kfree; |
945 | |
946 | rgpio_dev->of_args = *args; |
947 | /* |
948 | * We keep the device_node reference, but of_args.np is put at the end |
949 | * of __of_reset_control_get(), so get it one more time. |
950 | * Hold reference as long as rgpio_dev memory is valid. |
951 | */ |
952 | of_node_get(node: rgpio_dev->of_args.np); |
953 | pdev = platform_device_register_data(NULL, name: "reset-gpio" , id, |
954 | data: &rgpio_dev->of_args, |
955 | size: sizeof(rgpio_dev->of_args)); |
956 | ret = PTR_ERR_OR_ZERO(ptr: pdev); |
957 | if (ret) |
958 | goto err_put; |
959 | |
960 | list_add(new: &rgpio_dev->list, head: &reset_gpio_lookup_list); |
961 | |
962 | out: |
963 | mutex_unlock(lock: &reset_gpio_lookup_mutex); |
964 | |
965 | return 0; |
966 | |
967 | err_put: |
968 | of_node_put(node: rgpio_dev->of_args.np); |
969 | err_kfree: |
970 | kfree(objp: rgpio_dev); |
971 | err_ida_free: |
972 | ida_free(&reset_gpio_ida, id); |
973 | err_unlock: |
974 | mutex_unlock(lock: &reset_gpio_lookup_mutex); |
975 | |
976 | return ret; |
977 | } |
978 | |
979 | static struct reset_controller_dev *__reset_find_rcdev(const struct of_phandle_args *args, |
980 | bool gpio_fallback) |
981 | { |
982 | struct reset_controller_dev *rcdev; |
983 | |
984 | lockdep_assert_held(&reset_list_mutex); |
985 | |
986 | list_for_each_entry(rcdev, &reset_controller_list, list) { |
987 | if (gpio_fallback) { |
988 | if (rcdev->of_args && of_phandle_args_equal(a1: args, |
989 | a2: rcdev->of_args)) |
990 | return rcdev; |
991 | } else { |
992 | if (args->np == rcdev->of_node) |
993 | return rcdev; |
994 | } |
995 | } |
996 | |
997 | return NULL; |
998 | } |
999 | |
1000 | struct reset_control * |
1001 | __of_reset_control_get(struct device_node *node, const char *id, int index, |
1002 | bool shared, bool optional, bool acquired) |
1003 | { |
1004 | bool gpio_fallback = false; |
1005 | struct reset_control *rstc; |
1006 | struct reset_controller_dev *rcdev; |
1007 | struct of_phandle_args args; |
1008 | int rstc_id; |
1009 | int ret; |
1010 | |
1011 | if (!node) |
1012 | return ERR_PTR(error: -EINVAL); |
1013 | |
1014 | if (id) { |
1015 | index = of_property_match_string(np: node, |
1016 | propname: "reset-names" , string: id); |
1017 | if (index == -EILSEQ) |
1018 | return ERR_PTR(error: index); |
1019 | if (index < 0) |
1020 | return optional ? NULL : ERR_PTR(error: -ENOENT); |
1021 | } |
1022 | |
1023 | ret = of_parse_phandle_with_args(np: node, list_name: "resets" , cells_name: "#reset-cells" , |
1024 | index, out_args: &args); |
1025 | if (ret == -EINVAL) |
1026 | return ERR_PTR(error: ret); |
1027 | if (ret) { |
1028 | if (!IS_ENABLED(CONFIG_RESET_GPIO)) |
1029 | return optional ? NULL : ERR_PTR(error: ret); |
1030 | |
1031 | /* |
1032 | * There can be only one reset-gpio for regular devices, so |
1033 | * don't bother with the "reset-gpios" phandle index. |
1034 | */ |
1035 | ret = of_parse_phandle_with_args(np: node, list_name: "reset-gpios" , cells_name: "#gpio-cells" , |
1036 | index: 0, out_args: &args); |
1037 | if (ret) |
1038 | return optional ? NULL : ERR_PTR(error: ret); |
1039 | |
1040 | gpio_fallback = true; |
1041 | |
1042 | ret = __reset_add_reset_gpio_device(args: &args); |
1043 | if (ret) { |
1044 | rstc = ERR_PTR(error: ret); |
1045 | goto out_put; |
1046 | } |
1047 | } |
1048 | |
1049 | mutex_lock(&reset_list_mutex); |
1050 | rcdev = __reset_find_rcdev(args: &args, gpio_fallback); |
1051 | if (!rcdev) { |
1052 | rstc = ERR_PTR(error: -EPROBE_DEFER); |
1053 | goto out_unlock; |
1054 | } |
1055 | |
1056 | if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) { |
1057 | rstc = ERR_PTR(error: -EINVAL); |
1058 | goto out_unlock; |
1059 | } |
1060 | |
1061 | rstc_id = rcdev->of_xlate(rcdev, &args); |
1062 | if (rstc_id < 0) { |
1063 | rstc = ERR_PTR(error: rstc_id); |
1064 | goto out_unlock; |
1065 | } |
1066 | |
1067 | /* reset_list_mutex also protects the rcdev's reset_control list */ |
1068 | rstc = __reset_control_get_internal(rcdev, index: rstc_id, shared, acquired); |
1069 | |
1070 | out_unlock: |
1071 | mutex_unlock(lock: &reset_list_mutex); |
1072 | out_put: |
1073 | of_node_put(node: args.np); |
1074 | |
1075 | return rstc; |
1076 | } |
1077 | EXPORT_SYMBOL_GPL(__of_reset_control_get); |
1078 | |
1079 | static struct reset_controller_dev * |
1080 | __reset_controller_by_name(const char *name) |
1081 | { |
1082 | struct reset_controller_dev *rcdev; |
1083 | |
1084 | lockdep_assert_held(&reset_list_mutex); |
1085 | |
1086 | list_for_each_entry(rcdev, &reset_controller_list, list) { |
1087 | if (!rcdev->dev) |
1088 | continue; |
1089 | |
1090 | if (!strcmp(name, dev_name(dev: rcdev->dev))) |
1091 | return rcdev; |
1092 | } |
1093 | |
1094 | return NULL; |
1095 | } |
1096 | |
1097 | static struct reset_control * |
1098 | __reset_control_get_from_lookup(struct device *dev, const char *con_id, |
1099 | bool shared, bool optional, bool acquired) |
1100 | { |
1101 | const struct reset_control_lookup *lookup; |
1102 | struct reset_controller_dev *rcdev; |
1103 | const char *dev_id = dev_name(dev); |
1104 | struct reset_control *rstc = NULL; |
1105 | |
1106 | mutex_lock(&reset_lookup_mutex); |
1107 | |
1108 | list_for_each_entry(lookup, &reset_lookup_list, list) { |
1109 | if (strcmp(lookup->dev_id, dev_id)) |
1110 | continue; |
1111 | |
1112 | if ((!con_id && !lookup->con_id) || |
1113 | ((con_id && lookup->con_id) && |
1114 | !strcmp(con_id, lookup->con_id))) { |
1115 | mutex_lock(&reset_list_mutex); |
1116 | rcdev = __reset_controller_by_name(name: lookup->provider); |
1117 | if (!rcdev) { |
1118 | mutex_unlock(lock: &reset_list_mutex); |
1119 | mutex_unlock(lock: &reset_lookup_mutex); |
1120 | /* Reset provider may not be ready yet. */ |
1121 | return ERR_PTR(error: -EPROBE_DEFER); |
1122 | } |
1123 | |
1124 | rstc = __reset_control_get_internal(rcdev, |
1125 | index: lookup->index, |
1126 | shared, acquired); |
1127 | mutex_unlock(lock: &reset_list_mutex); |
1128 | break; |
1129 | } |
1130 | } |
1131 | |
1132 | mutex_unlock(lock: &reset_lookup_mutex); |
1133 | |
1134 | if (!rstc) |
1135 | return optional ? NULL : ERR_PTR(error: -ENOENT); |
1136 | |
1137 | return rstc; |
1138 | } |
1139 | |
1140 | struct reset_control *__reset_control_get(struct device *dev, const char *id, |
1141 | int index, bool shared, bool optional, |
1142 | bool acquired) |
1143 | { |
1144 | if (WARN_ON(shared && acquired)) |
1145 | return ERR_PTR(error: -EINVAL); |
1146 | |
1147 | if (dev->of_node) |
1148 | return __of_reset_control_get(dev->of_node, id, index, shared, |
1149 | optional, acquired); |
1150 | |
1151 | return __reset_control_get_from_lookup(dev, con_id: id, shared, optional, |
1152 | acquired); |
1153 | } |
1154 | EXPORT_SYMBOL_GPL(__reset_control_get); |
1155 | |
1156 | int __reset_control_bulk_get(struct device *dev, int num_rstcs, |
1157 | struct reset_control_bulk_data *rstcs, |
1158 | bool shared, bool optional, bool acquired) |
1159 | { |
1160 | int ret, i; |
1161 | |
1162 | for (i = 0; i < num_rstcs; i++) { |
1163 | rstcs[i].rstc = __reset_control_get(dev, rstcs[i].id, 0, |
1164 | shared, optional, acquired); |
1165 | if (IS_ERR(ptr: rstcs[i].rstc)) { |
1166 | ret = PTR_ERR(ptr: rstcs[i].rstc); |
1167 | goto err; |
1168 | } |
1169 | } |
1170 | |
1171 | return 0; |
1172 | |
1173 | err: |
1174 | mutex_lock(&reset_list_mutex); |
1175 | while (i--) |
1176 | __reset_control_put_internal(rstc: rstcs[i].rstc); |
1177 | mutex_unlock(lock: &reset_list_mutex); |
1178 | return ret; |
1179 | } |
1180 | EXPORT_SYMBOL_GPL(__reset_control_bulk_get); |
1181 | |
1182 | static void reset_control_array_put(struct reset_control_array *resets) |
1183 | { |
1184 | int i; |
1185 | |
1186 | mutex_lock(&reset_list_mutex); |
1187 | for (i = 0; i < resets->num_rstcs; i++) |
1188 | __reset_control_put_internal(rstc: resets->rstc[i]); |
1189 | mutex_unlock(lock: &reset_list_mutex); |
1190 | kfree(objp: resets); |
1191 | } |
1192 | |
1193 | /** |
1194 | * reset_control_put - free the reset controller |
1195 | * @rstc: reset controller |
1196 | */ |
1197 | void reset_control_put(struct reset_control *rstc) |
1198 | { |
1199 | if (IS_ERR_OR_NULL(ptr: rstc)) |
1200 | return; |
1201 | |
1202 | if (reset_control_is_array(rstc)) { |
1203 | reset_control_array_put(resets: rstc_to_array(rstc)); |
1204 | return; |
1205 | } |
1206 | |
1207 | mutex_lock(&reset_list_mutex); |
1208 | __reset_control_put_internal(rstc); |
1209 | mutex_unlock(lock: &reset_list_mutex); |
1210 | } |
1211 | EXPORT_SYMBOL_GPL(reset_control_put); |
1212 | |
1213 | /** |
1214 | * reset_control_bulk_put - free the reset controllers |
1215 | * @num_rstcs: number of entries in rstcs array |
1216 | * @rstcs: array of struct reset_control_bulk_data with reset controls set |
1217 | */ |
1218 | void reset_control_bulk_put(int num_rstcs, struct reset_control_bulk_data *rstcs) |
1219 | { |
1220 | mutex_lock(&reset_list_mutex); |
1221 | while (num_rstcs--) |
1222 | __reset_control_put_internal(rstc: rstcs[num_rstcs].rstc); |
1223 | mutex_unlock(lock: &reset_list_mutex); |
1224 | } |
1225 | EXPORT_SYMBOL_GPL(reset_control_bulk_put); |
1226 | |
1227 | static void devm_reset_control_release(struct device *dev, void *res) |
1228 | { |
1229 | reset_control_put(*(struct reset_control **)res); |
1230 | } |
1231 | |
1232 | struct reset_control * |
1233 | __devm_reset_control_get(struct device *dev, const char *id, int index, |
1234 | bool shared, bool optional, bool acquired) |
1235 | { |
1236 | struct reset_control **ptr, *rstc; |
1237 | |
1238 | ptr = devres_alloc(devm_reset_control_release, sizeof(*ptr), |
1239 | GFP_KERNEL); |
1240 | if (!ptr) |
1241 | return ERR_PTR(error: -ENOMEM); |
1242 | |
1243 | rstc = __reset_control_get(dev, id, index, shared, optional, acquired); |
1244 | if (IS_ERR_OR_NULL(ptr: rstc)) { |
1245 | devres_free(res: ptr); |
1246 | return rstc; |
1247 | } |
1248 | |
1249 | *ptr = rstc; |
1250 | devres_add(dev, res: ptr); |
1251 | |
1252 | return rstc; |
1253 | } |
1254 | EXPORT_SYMBOL_GPL(__devm_reset_control_get); |
1255 | |
1256 | struct reset_control_bulk_devres { |
1257 | int num_rstcs; |
1258 | struct reset_control_bulk_data *rstcs; |
1259 | }; |
1260 | |
1261 | static void devm_reset_control_bulk_release(struct device *dev, void *res) |
1262 | { |
1263 | struct reset_control_bulk_devres *devres = res; |
1264 | |
1265 | reset_control_bulk_put(devres->num_rstcs, devres->rstcs); |
1266 | } |
1267 | |
1268 | int __devm_reset_control_bulk_get(struct device *dev, int num_rstcs, |
1269 | struct reset_control_bulk_data *rstcs, |
1270 | bool shared, bool optional, bool acquired) |
1271 | { |
1272 | struct reset_control_bulk_devres *ptr; |
1273 | int ret; |
1274 | |
1275 | ptr = devres_alloc(devm_reset_control_bulk_release, sizeof(*ptr), |
1276 | GFP_KERNEL); |
1277 | if (!ptr) |
1278 | return -ENOMEM; |
1279 | |
1280 | ret = __reset_control_bulk_get(dev, num_rstcs, rstcs, shared, optional, acquired); |
1281 | if (ret < 0) { |
1282 | devres_free(res: ptr); |
1283 | return ret; |
1284 | } |
1285 | |
1286 | ptr->num_rstcs = num_rstcs; |
1287 | ptr->rstcs = rstcs; |
1288 | devres_add(dev, res: ptr); |
1289 | |
1290 | return 0; |
1291 | } |
1292 | EXPORT_SYMBOL_GPL(__devm_reset_control_bulk_get); |
1293 | |
1294 | /** |
1295 | * __device_reset - find reset controller associated with the device |
1296 | * and perform reset |
1297 | * @dev: device to be reset by the controller |
1298 | * @optional: whether it is optional to reset the device |
1299 | * |
1300 | * Convenience wrapper for __reset_control_get() and reset_control_reset(). |
1301 | * This is useful for the common case of devices with single, dedicated reset |
1302 | * lines. _RST firmware method will be called for devices with ACPI. |
1303 | */ |
1304 | int __device_reset(struct device *dev, bool optional) |
1305 | { |
1306 | struct reset_control *rstc; |
1307 | int ret; |
1308 | |
1309 | #ifdef CONFIG_ACPI |
1310 | acpi_handle handle = ACPI_HANDLE(dev); |
1311 | |
1312 | if (handle) { |
1313 | if (!acpi_has_method(handle, name: "_RST" )) |
1314 | return optional ? 0 : -ENOENT; |
1315 | if (ACPI_FAILURE(acpi_evaluate_object(handle, "_RST" , NULL, |
1316 | NULL))) |
1317 | return -EIO; |
1318 | } |
1319 | #endif |
1320 | |
1321 | rstc = __reset_control_get(dev, NULL, 0, 0, optional, true); |
1322 | if (IS_ERR(ptr: rstc)) |
1323 | return PTR_ERR(ptr: rstc); |
1324 | |
1325 | ret = reset_control_reset(rstc); |
1326 | |
1327 | reset_control_put(rstc); |
1328 | |
1329 | return ret; |
1330 | } |
1331 | EXPORT_SYMBOL_GPL(__device_reset); |
1332 | |
1333 | /* |
1334 | * APIs to manage an array of reset controls. |
1335 | */ |
1336 | |
1337 | /** |
1338 | * of_reset_control_get_count - Count number of resets available with a device |
1339 | * |
1340 | * @node: device node that contains 'resets'. |
1341 | * |
1342 | * Returns positive reset count on success, or error number on failure and |
1343 | * on count being zero. |
1344 | */ |
1345 | static int of_reset_control_get_count(struct device_node *node) |
1346 | { |
1347 | int count; |
1348 | |
1349 | if (!node) |
1350 | return -EINVAL; |
1351 | |
1352 | count = of_count_phandle_with_args(np: node, list_name: "resets" , cells_name: "#reset-cells" ); |
1353 | if (count == 0) |
1354 | count = -ENOENT; |
1355 | |
1356 | return count; |
1357 | } |
1358 | |
1359 | /** |
1360 | * of_reset_control_array_get - Get a list of reset controls using |
1361 | * device node. |
1362 | * |
1363 | * @np: device node for the device that requests the reset controls array |
1364 | * @shared: whether reset controls are shared or not |
1365 | * @optional: whether it is optional to get the reset controls |
1366 | * @acquired: only one reset control may be acquired for a given controller |
1367 | * and ID |
1368 | * |
1369 | * Returns pointer to allocated reset_control on success or error on failure |
1370 | */ |
1371 | struct reset_control * |
1372 | of_reset_control_array_get(struct device_node *np, bool shared, bool optional, |
1373 | bool acquired) |
1374 | { |
1375 | struct reset_control_array *resets; |
1376 | struct reset_control *rstc; |
1377 | int num, i; |
1378 | |
1379 | num = of_reset_control_get_count(node: np); |
1380 | if (num < 0) |
1381 | return optional ? NULL : ERR_PTR(error: num); |
1382 | |
1383 | resets = kzalloc(struct_size(resets, rstc, num), GFP_KERNEL); |
1384 | if (!resets) |
1385 | return ERR_PTR(error: -ENOMEM); |
1386 | resets->num_rstcs = num; |
1387 | |
1388 | for (i = 0; i < num; i++) { |
1389 | rstc = __of_reset_control_get(np, NULL, i, shared, optional, |
1390 | acquired); |
1391 | if (IS_ERR(ptr: rstc)) |
1392 | goto err_rst; |
1393 | resets->rstc[i] = rstc; |
1394 | } |
1395 | resets->base.array = true; |
1396 | |
1397 | return &resets->base; |
1398 | |
1399 | err_rst: |
1400 | mutex_lock(&reset_list_mutex); |
1401 | while (--i >= 0) |
1402 | __reset_control_put_internal(rstc: resets->rstc[i]); |
1403 | mutex_unlock(lock: &reset_list_mutex); |
1404 | |
1405 | kfree(objp: resets); |
1406 | |
1407 | return rstc; |
1408 | } |
1409 | EXPORT_SYMBOL_GPL(of_reset_control_array_get); |
1410 | |
1411 | /** |
1412 | * devm_reset_control_array_get - Resource managed reset control array get |
1413 | * |
1414 | * @dev: device that requests the list of reset controls |
1415 | * @shared: whether reset controls are shared or not |
1416 | * @optional: whether it is optional to get the reset controls |
1417 | * |
1418 | * The reset control array APIs are intended for a list of resets |
1419 | * that just have to be asserted or deasserted, without any |
1420 | * requirements on the order. |
1421 | * |
1422 | * Returns pointer to allocated reset_control on success or error on failure |
1423 | */ |
1424 | struct reset_control * |
1425 | devm_reset_control_array_get(struct device *dev, bool shared, bool optional) |
1426 | { |
1427 | struct reset_control **ptr, *rstc; |
1428 | |
1429 | ptr = devres_alloc(devm_reset_control_release, sizeof(*ptr), |
1430 | GFP_KERNEL); |
1431 | if (!ptr) |
1432 | return ERR_PTR(error: -ENOMEM); |
1433 | |
1434 | rstc = of_reset_control_array_get(dev->of_node, shared, optional, true); |
1435 | if (IS_ERR_OR_NULL(ptr: rstc)) { |
1436 | devres_free(res: ptr); |
1437 | return rstc; |
1438 | } |
1439 | |
1440 | *ptr = rstc; |
1441 | devres_add(dev, res: ptr); |
1442 | |
1443 | return rstc; |
1444 | } |
1445 | EXPORT_SYMBOL_GPL(devm_reset_control_array_get); |
1446 | |
1447 | static int reset_control_get_count_from_lookup(struct device *dev) |
1448 | { |
1449 | const struct reset_control_lookup *lookup; |
1450 | const char *dev_id; |
1451 | int count = 0; |
1452 | |
1453 | if (!dev) |
1454 | return -EINVAL; |
1455 | |
1456 | dev_id = dev_name(dev); |
1457 | mutex_lock(&reset_lookup_mutex); |
1458 | |
1459 | list_for_each_entry(lookup, &reset_lookup_list, list) { |
1460 | if (!strcmp(lookup->dev_id, dev_id)) |
1461 | count++; |
1462 | } |
1463 | |
1464 | mutex_unlock(lock: &reset_lookup_mutex); |
1465 | |
1466 | if (count == 0) |
1467 | count = -ENOENT; |
1468 | |
1469 | return count; |
1470 | } |
1471 | |
1472 | /** |
1473 | * reset_control_get_count - Count number of resets available with a device |
1474 | * |
1475 | * @dev: device for which to return the number of resets |
1476 | * |
1477 | * Returns positive reset count on success, or error number on failure and |
1478 | * on count being zero. |
1479 | */ |
1480 | int reset_control_get_count(struct device *dev) |
1481 | { |
1482 | if (dev->of_node) |
1483 | return of_reset_control_get_count(node: dev->of_node); |
1484 | |
1485 | return reset_control_get_count_from_lookup(dev); |
1486 | } |
1487 | EXPORT_SYMBOL_GPL(reset_control_get_count); |
1488 | |