1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Reset Controller framework
5 * Copyright 2013 Philipp Zabel, Pengutronix
7 #include <linux/atomic.h>
8 #include <linux/device.h>
10 #include <linux/export.h>
11 #include <linux/kernel.h>
12 #include <linux/kref.h>
13 #include <linux/module.h>
15 #include <linux/reset.h>
16 #include <linux/reset-controller.h>
17 #include <linux/slab.h>
19 static DEFINE_MUTEX(reset_list_mutex);
20 static LIST_HEAD(reset_controller_list);
22 static DEFINE_MUTEX(reset_lookup_mutex);
23 static LIST_HEAD(reset_lookup_list);
26 * struct reset_control - a reset control
27 * @rcdev: a pointer to the reset controller device
28 * this reset control belongs to
29 * @list: list entry for the rcdev's reset controller list
30 * @id: ID of the reset controller in the reset
32 * @refcnt: Number of gets of this reset_control
33 * @acquired: Only one reset_control may be acquired for a given rcdev and id.
34 * @shared: Is this a shared (1), or an exclusive (0) reset_control?
35 * @array: Is this an array of reset controls (1)?
36 * @deassert_count: Number of times this reset line has been deasserted
37 * @triggered_count: Number of times this reset line has been reset. Currently
38 * only used for shared resets, which means that the value
39 * will be either 0 or 1.
41 struct reset_control {
42 struct reset_controller_dev *rcdev;
43 struct list_head list;
49 atomic_t deassert_count;
50 atomic_t triggered_count;
54 * struct reset_control_array - an array of reset controls
55 * @base: reset control for compatibility with reset control API functions
56 * @num_rstcs: number of reset controls
57 * @rstc: array of reset controls
59 struct reset_control_array {
60 struct reset_control base;
61 unsigned int num_rstcs;
62 struct reset_control *rstc[];
65 static const char *rcdev_name(struct reset_controller_dev *rcdev)
68 return dev_name(rcdev->dev);
71 return rcdev->of_node->full_name;
77 * of_reset_simple_xlate - translate reset_spec to the reset line number
78 * @rcdev: a pointer to the reset controller device
79 * @reset_spec: reset line specifier as found in the device tree
81 * This static translation function is used by default if of_xlate in
82 * :c:type:`reset_controller_dev` is not set. It is useful for all reset
83 * controllers with 1:1 mapping, where reset lines can be indexed by number
86 static int of_reset_simple_xlate(struct reset_controller_dev *rcdev,
87 const struct of_phandle_args *reset_spec)
89 if (reset_spec->args[0] >= rcdev->nr_resets)
92 return reset_spec->args[0];
96 * reset_controller_register - register a reset controller device
97 * @rcdev: a pointer to the initialized reset controller device
99 int reset_controller_register(struct reset_controller_dev *rcdev)
101 if (!rcdev->of_xlate) {
102 rcdev->of_reset_n_cells = 1;
103 rcdev->of_xlate = of_reset_simple_xlate;
106 INIT_LIST_HEAD(&rcdev->reset_control_head);
108 mutex_lock(&reset_list_mutex);
109 list_add(&rcdev->list, &reset_controller_list);
110 mutex_unlock(&reset_list_mutex);
114 EXPORT_SYMBOL_GPL(reset_controller_register);
117 * reset_controller_unregister - unregister a reset controller device
118 * @rcdev: a pointer to the reset controller device
120 void reset_controller_unregister(struct reset_controller_dev *rcdev)
122 mutex_lock(&reset_list_mutex);
123 list_del(&rcdev->list);
124 mutex_unlock(&reset_list_mutex);
126 EXPORT_SYMBOL_GPL(reset_controller_unregister);
128 static void devm_reset_controller_release(struct device *dev, void *res)
130 reset_controller_unregister(*(struct reset_controller_dev **)res);
134 * devm_reset_controller_register - resource managed reset_controller_register()
135 * @dev: device that is registering this reset controller
136 * @rcdev: a pointer to the initialized reset controller device
138 * Managed reset_controller_register(). For reset controllers registered by
139 * this function, reset_controller_unregister() is automatically called on
140 * driver detach. See reset_controller_register() for more information.
142 int devm_reset_controller_register(struct device *dev,
143 struct reset_controller_dev *rcdev)
145 struct reset_controller_dev **rcdevp;
148 rcdevp = devres_alloc(devm_reset_controller_release, sizeof(*rcdevp),
153 ret = reset_controller_register(rcdev);
160 devres_add(dev, rcdevp);
164 EXPORT_SYMBOL_GPL(devm_reset_controller_register);
167 * reset_controller_add_lookup - register a set of lookup entries
168 * @lookup: array of reset lookup entries
169 * @num_entries: number of entries in the lookup array
171 void reset_controller_add_lookup(struct reset_control_lookup *lookup,
172 unsigned int num_entries)
174 struct reset_control_lookup *entry;
177 mutex_lock(&reset_lookup_mutex);
178 for (i = 0; i < num_entries; i++) {
181 if (!entry->dev_id || !entry->provider) {
182 pr_warn("%s(): reset lookup entry badly specified, skipping\n",
187 list_add_tail(&entry->list, &reset_lookup_list);
189 mutex_unlock(&reset_lookup_mutex);
191 EXPORT_SYMBOL_GPL(reset_controller_add_lookup);
193 static inline struct reset_control_array *
194 rstc_to_array(struct reset_control *rstc) {
195 return container_of(rstc, struct reset_control_array, base);
198 static int reset_control_array_reset(struct reset_control_array *resets)
202 for (i = 0; i < resets->num_rstcs; i++) {
203 ret = reset_control_reset(resets->rstc[i]);
211 static int reset_control_array_rearm(struct reset_control_array *resets)
213 struct reset_control *rstc;
216 for (i = 0; i < resets->num_rstcs; i++) {
217 rstc = resets->rstc[i];
222 if (WARN_ON(IS_ERR(rstc)))
226 if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))
234 for (i = 0; i < resets->num_rstcs; i++) {
235 rstc = resets->rstc[i];
237 if (rstc && rstc->shared)
238 WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);
244 static int reset_control_array_assert(struct reset_control_array *resets)
248 for (i = 0; i < resets->num_rstcs; i++) {
249 ret = reset_control_assert(resets->rstc[i]);
258 reset_control_deassert(resets->rstc[i]);
262 static int reset_control_array_deassert(struct reset_control_array *resets)
266 for (i = 0; i < resets->num_rstcs; i++) {
267 ret = reset_control_deassert(resets->rstc[i]);
276 reset_control_assert(resets->rstc[i]);
280 static int reset_control_array_acquire(struct reset_control_array *resets)
285 for (i = 0; i < resets->num_rstcs; i++) {
286 err = reset_control_acquire(resets->rstc[i]);
295 reset_control_release(resets->rstc[i]);
300 static void reset_control_array_release(struct reset_control_array *resets)
304 for (i = 0; i < resets->num_rstcs; i++)
305 reset_control_release(resets->rstc[i]);
308 static inline bool reset_control_is_array(struct reset_control *rstc)
314 * reset_control_reset - reset the controlled device
315 * @rstc: reset controller
317 * On a shared reset line the actual reset pulse is only triggered once for the
318 * lifetime of the reset_control instance: for all but the first caller this is
320 * Consumers must not use reset_control_(de)assert on shared reset lines when
321 * reset_control_reset has been used.
323 * If rstc is NULL it is an optional reset and the function will just
326 int reset_control_reset(struct reset_control *rstc)
333 if (WARN_ON(IS_ERR(rstc)))
336 if (reset_control_is_array(rstc))
337 return reset_control_array_reset(rstc_to_array(rstc));
339 if (!rstc->rcdev->ops->reset)
343 if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))
346 if (atomic_inc_return(&rstc->triggered_count) != 1)
353 ret = rstc->rcdev->ops->reset(rstc->rcdev, rstc->id);
354 if (rstc->shared && ret)
355 atomic_dec(&rstc->triggered_count);
359 EXPORT_SYMBOL_GPL(reset_control_reset);
362 * reset_control_bulk_reset - reset the controlled devices in order
363 * @num_rstcs: number of entries in rstcs array
364 * @rstcs: array of struct reset_control_bulk_data with reset controls set
366 * Issue a reset on all provided reset controls, in order.
368 * See also: reset_control_reset()
370 int reset_control_bulk_reset(int num_rstcs,
371 struct reset_control_bulk_data *rstcs)
375 for (i = 0; i < num_rstcs; i++) {
376 ret = reset_control_reset(rstcs[i].rstc);
383 EXPORT_SYMBOL_GPL(reset_control_bulk_reset);
386 * reset_control_rearm - allow shared reset line to be re-triggered"
387 * @rstc: reset controller
389 * On a shared reset line the actual reset pulse is only triggered once for the
390 * lifetime of the reset_control instance, except if this call is used.
392 * Calls to this function must be balanced with calls to reset_control_reset,
393 * a warning is thrown in case triggered_count ever dips below 0.
395 * Consumers must not use reset_control_(de)assert on shared reset lines when
396 * reset_control_reset or reset_control_rearm have been used.
398 * If rstc is NULL the function will just return 0.
400 int reset_control_rearm(struct reset_control *rstc)
405 if (WARN_ON(IS_ERR(rstc)))
408 if (reset_control_is_array(rstc))
409 return reset_control_array_rearm(rstc_to_array(rstc));
412 if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))
415 WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);
423 EXPORT_SYMBOL_GPL(reset_control_rearm);
426 * reset_control_assert - asserts the reset line
427 * @rstc: reset controller
429 * Calling this on an exclusive reset controller guarantees that the reset
430 * will be asserted. When called on a shared reset controller the line may
431 * still be deasserted, as long as other users keep it so.
433 * For shared reset controls a driver cannot expect the hw's registers and
434 * internal state to be reset, but must be prepared for this to happen.
435 * Consumers must not use reset_control_reset on shared reset lines when
436 * reset_control_(de)assert has been used.
438 * If rstc is NULL it is an optional reset and the function will just
441 int reset_control_assert(struct reset_control *rstc)
446 if (WARN_ON(IS_ERR(rstc)))
449 if (reset_control_is_array(rstc))
450 return reset_control_array_assert(rstc_to_array(rstc));
453 if (WARN_ON(atomic_read(&rstc->triggered_count) != 0))
456 if (WARN_ON(atomic_read(&rstc->deassert_count) == 0))
459 if (atomic_dec_return(&rstc->deassert_count) != 0)
463 * Shared reset controls allow the reset line to be in any state
464 * after this call, so doing nothing is a valid option.
466 if (!rstc->rcdev->ops->assert)
470 * If the reset controller does not implement .assert(), there
471 * is no way to guarantee that the reset line is asserted after
474 if (!rstc->rcdev->ops->assert)
477 if (!rstc->acquired) {
478 WARN(1, "reset %s (ID: %u) is not acquired\n",
479 rcdev_name(rstc->rcdev), rstc->id);
484 return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id);
486 EXPORT_SYMBOL_GPL(reset_control_assert);
489 * reset_control_bulk_assert - asserts the reset lines in order
490 * @num_rstcs: number of entries in rstcs array
491 * @rstcs: array of struct reset_control_bulk_data with reset controls set
493 * Assert the reset lines for all provided reset controls, in order.
494 * If an assertion fails, already asserted resets are deasserted again.
496 * See also: reset_control_assert()
498 int reset_control_bulk_assert(int num_rstcs,
499 struct reset_control_bulk_data *rstcs)
503 for (i = 0; i < num_rstcs; i++) {
504 ret = reset_control_assert(rstcs[i].rstc);
513 reset_control_deassert(rstcs[i].rstc);
516 EXPORT_SYMBOL_GPL(reset_control_bulk_assert);
519 * reset_control_deassert - deasserts the reset line
520 * @rstc: reset controller
522 * After calling this function, the reset is guaranteed to be deasserted.
523 * Consumers must not use reset_control_reset on shared reset lines when
524 * reset_control_(de)assert has been used.
526 * If rstc is NULL it is an optional reset and the function will just
529 int reset_control_deassert(struct reset_control *rstc)
534 if (WARN_ON(IS_ERR(rstc)))
537 if (reset_control_is_array(rstc))
538 return reset_control_array_deassert(rstc_to_array(rstc));
541 if (WARN_ON(atomic_read(&rstc->triggered_count) != 0))
544 if (atomic_inc_return(&rstc->deassert_count) != 1)
547 if (!rstc->acquired) {
548 WARN(1, "reset %s (ID: %u) is not acquired\n",
549 rcdev_name(rstc->rcdev), rstc->id);
555 * If the reset controller does not implement .deassert(), we assume
556 * that it handles self-deasserting reset lines via .reset(). In that
557 * case, the reset lines are deasserted by default. If that is not the
558 * case, the reset controller driver should implement .deassert() and
561 if (!rstc->rcdev->ops->deassert)
564 return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id);
566 EXPORT_SYMBOL_GPL(reset_control_deassert);
569 * reset_control_bulk_deassert - deasserts the reset lines in reverse order
570 * @num_rstcs: number of entries in rstcs array
571 * @rstcs: array of struct reset_control_bulk_data with reset controls set
573 * Deassert the reset lines for all provided reset controls, in reverse order.
574 * If a deassertion fails, already deasserted resets are asserted again.
576 * See also: reset_control_deassert()
578 int reset_control_bulk_deassert(int num_rstcs,
579 struct reset_control_bulk_data *rstcs)
583 for (i = num_rstcs - 1; i >= 0; i--) {
584 ret = reset_control_deassert(rstcs[i].rstc);
592 while (i < num_rstcs)
593 reset_control_assert(rstcs[i++].rstc);
596 EXPORT_SYMBOL_GPL(reset_control_bulk_deassert);
599 * reset_control_status - returns a negative errno if not supported, a
600 * positive value if the reset line is asserted, or zero if the reset
601 * line is not asserted or if the desc is NULL (optional reset).
602 * @rstc: reset controller
604 int reset_control_status(struct reset_control *rstc)
609 if (WARN_ON(IS_ERR(rstc)) || reset_control_is_array(rstc))
612 if (rstc->rcdev->ops->status)
613 return rstc->rcdev->ops->status(rstc->rcdev, rstc->id);
617 EXPORT_SYMBOL_GPL(reset_control_status);
620 * reset_control_acquire() - acquires a reset control for exclusive use
621 * @rstc: reset control
623 * This is used to explicitly acquire a reset control for exclusive use. Note
624 * that exclusive resets are requested as acquired by default. In order for a
625 * second consumer to be able to control the reset, the first consumer has to
626 * release it first. Typically the easiest way to achieve this is to call the
627 * reset_control_get_exclusive_released() to obtain an instance of the reset
628 * control. Such reset controls are not acquired by default.
630 * Consumers implementing shared access to an exclusive reset need to follow
631 * a specific protocol in order to work together. Before consumers can change
632 * a reset they must acquire exclusive access using reset_control_acquire().
633 * After they are done operating the reset, they must release exclusive access
634 * with a call to reset_control_release(). Consumers are not granted exclusive
635 * access to the reset as long as another consumer hasn't released a reset.
637 * See also: reset_control_release()
639 int reset_control_acquire(struct reset_control *rstc)
641 struct reset_control *rc;
646 if (WARN_ON(IS_ERR(rstc)))
649 if (reset_control_is_array(rstc))
650 return reset_control_array_acquire(rstc_to_array(rstc));
652 mutex_lock(&reset_list_mutex);
654 if (rstc->acquired) {
655 mutex_unlock(&reset_list_mutex);
659 list_for_each_entry(rc, &rstc->rcdev->reset_control_head, list) {
660 if (rstc != rc && rstc->id == rc->id) {
662 mutex_unlock(&reset_list_mutex);
668 rstc->acquired = true;
670 mutex_unlock(&reset_list_mutex);
673 EXPORT_SYMBOL_GPL(reset_control_acquire);
676 * reset_control_bulk_acquire - acquires reset controls for exclusive use
677 * @num_rstcs: number of entries in rstcs array
678 * @rstcs: array of struct reset_control_bulk_data with reset controls set
680 * This is used to explicitly acquire reset controls requested with
681 * reset_control_bulk_get_exclusive_release() for temporary exclusive use.
683 * See also: reset_control_acquire(), reset_control_bulk_release()
685 int reset_control_bulk_acquire(int num_rstcs,
686 struct reset_control_bulk_data *rstcs)
690 for (i = 0; i < num_rstcs; i++) {
691 ret = reset_control_acquire(rstcs[i].rstc);
700 reset_control_release(rstcs[i].rstc);
703 EXPORT_SYMBOL_GPL(reset_control_bulk_acquire);
706 * reset_control_release() - releases exclusive access to a reset control
707 * @rstc: reset control
709 * Releases exclusive access right to a reset control previously obtained by a
710 * call to reset_control_acquire(). Until a consumer calls this function, no
711 * other consumers will be granted exclusive access.
713 * See also: reset_control_acquire()
715 void reset_control_release(struct reset_control *rstc)
717 if (!rstc || WARN_ON(IS_ERR(rstc)))
720 if (reset_control_is_array(rstc))
721 reset_control_array_release(rstc_to_array(rstc));
723 rstc->acquired = false;
725 EXPORT_SYMBOL_GPL(reset_control_release);
728 * reset_control_bulk_release() - releases exclusive access to reset controls
729 * @num_rstcs: number of entries in rstcs array
730 * @rstcs: array of struct reset_control_bulk_data with reset controls set
732 * Releases exclusive access right to reset controls previously obtained by a
733 * call to reset_control_bulk_acquire().
735 * See also: reset_control_release(), reset_control_bulk_acquire()
737 void reset_control_bulk_release(int num_rstcs,
738 struct reset_control_bulk_data *rstcs)
742 for (i = 0; i < num_rstcs; i++)
743 reset_control_release(rstcs[i].rstc);
745 EXPORT_SYMBOL_GPL(reset_control_bulk_release);
747 static struct reset_control *__reset_control_get_internal(
748 struct reset_controller_dev *rcdev,
749 unsigned int index, bool shared, bool acquired)
751 struct reset_control *rstc;
753 lockdep_assert_held(&reset_list_mutex);
755 list_for_each_entry(rstc, &rcdev->reset_control_head, list) {
756 if (rstc->id == index) {
758 * Allow creating a secondary exclusive reset_control
759 * that is initially not acquired for an already
760 * controlled reset line.
762 if (!rstc->shared && !shared && !acquired)
765 if (WARN_ON(!rstc->shared || !shared))
766 return ERR_PTR(-EBUSY);
768 kref_get(&rstc->refcnt);
773 rstc = kzalloc(sizeof(*rstc), GFP_KERNEL);
775 return ERR_PTR(-ENOMEM);
777 try_module_get(rcdev->owner);
780 list_add(&rstc->list, &rcdev->reset_control_head);
782 kref_init(&rstc->refcnt);
783 rstc->acquired = acquired;
784 rstc->shared = shared;
789 static void __reset_control_release(struct kref *kref)
791 struct reset_control *rstc = container_of(kref, struct reset_control,
794 lockdep_assert_held(&reset_list_mutex);
796 module_put(rstc->rcdev->owner);
798 list_del(&rstc->list);
802 static void __reset_control_put_internal(struct reset_control *rstc)
804 lockdep_assert_held(&reset_list_mutex);
806 kref_put(&rstc->refcnt, __reset_control_release);
809 struct reset_control *__of_reset_control_get(struct device_node *node,
810 const char *id, int index, bool shared,
811 bool optional, bool acquired)
813 struct reset_control *rstc;
814 struct reset_controller_dev *r, *rcdev;
815 struct of_phandle_args args;
820 return ERR_PTR(-EINVAL);
823 index = of_property_match_string(node,
825 if (index == -EILSEQ)
826 return ERR_PTR(index);
828 return optional ? NULL : ERR_PTR(-ENOENT);
831 ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",
836 return optional ? NULL : ERR_PTR(ret);
838 mutex_lock(&reset_list_mutex);
840 list_for_each_entry(r, &reset_controller_list, list) {
841 if (args.np == r->of_node) {
848 rstc = ERR_PTR(-EPROBE_DEFER);
852 if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) {
853 rstc = ERR_PTR(-EINVAL);
857 rstc_id = rcdev->of_xlate(rcdev, &args);
859 rstc = ERR_PTR(rstc_id);
863 /* reset_list_mutex also protects the rcdev's reset_control list */
864 rstc = __reset_control_get_internal(rcdev, rstc_id, shared, acquired);
867 mutex_unlock(&reset_list_mutex);
868 of_node_put(args.np);
872 EXPORT_SYMBOL_GPL(__of_reset_control_get);
874 static struct reset_controller_dev *
875 __reset_controller_by_name(const char *name)
877 struct reset_controller_dev *rcdev;
879 lockdep_assert_held(&reset_list_mutex);
881 list_for_each_entry(rcdev, &reset_controller_list, list) {
885 if (!strcmp(name, dev_name(rcdev->dev)))
892 static struct reset_control *
893 __reset_control_get_from_lookup(struct device *dev, const char *con_id,
894 bool shared, bool optional, bool acquired)
896 const struct reset_control_lookup *lookup;
897 struct reset_controller_dev *rcdev;
898 const char *dev_id = dev_name(dev);
899 struct reset_control *rstc = NULL;
901 mutex_lock(&reset_lookup_mutex);
903 list_for_each_entry(lookup, &reset_lookup_list, list) {
904 if (strcmp(lookup->dev_id, dev_id))
907 if ((!con_id && !lookup->con_id) ||
908 ((con_id && lookup->con_id) &&
909 !strcmp(con_id, lookup->con_id))) {
910 mutex_lock(&reset_list_mutex);
911 rcdev = __reset_controller_by_name(lookup->provider);
913 mutex_unlock(&reset_list_mutex);
914 mutex_unlock(&reset_lookup_mutex);
915 /* Reset provider may not be ready yet. */
916 return ERR_PTR(-EPROBE_DEFER);
919 rstc = __reset_control_get_internal(rcdev,
922 mutex_unlock(&reset_list_mutex);
927 mutex_unlock(&reset_lookup_mutex);
930 return optional ? NULL : ERR_PTR(-ENOENT);
935 struct reset_control *__reset_control_get(struct device *dev, const char *id,
936 int index, bool shared, bool optional,
939 if (WARN_ON(shared && acquired))
940 return ERR_PTR(-EINVAL);
943 return __of_reset_control_get(dev->of_node, id, index, shared,
946 return __reset_control_get_from_lookup(dev, id, shared, optional,
949 EXPORT_SYMBOL_GPL(__reset_control_get);
951 int __reset_control_bulk_get(struct device *dev, int num_rstcs,
952 struct reset_control_bulk_data *rstcs,
953 bool shared, bool optional, bool acquired)
957 for (i = 0; i < num_rstcs; i++) {
958 rstcs[i].rstc = __reset_control_get(dev, rstcs[i].id, 0,
959 shared, optional, acquired);
960 if (IS_ERR(rstcs[i].rstc)) {
961 ret = PTR_ERR(rstcs[i].rstc);
969 mutex_lock(&reset_list_mutex);
971 __reset_control_put_internal(rstcs[i].rstc);
972 mutex_unlock(&reset_list_mutex);
975 EXPORT_SYMBOL_GPL(__reset_control_bulk_get);
977 static void reset_control_array_put(struct reset_control_array *resets)
981 mutex_lock(&reset_list_mutex);
982 for (i = 0; i < resets->num_rstcs; i++)
983 __reset_control_put_internal(resets->rstc[i]);
984 mutex_unlock(&reset_list_mutex);
989 * reset_control_put - free the reset controller
990 * @rstc: reset controller
992 void reset_control_put(struct reset_control *rstc)
994 if (IS_ERR_OR_NULL(rstc))
997 if (reset_control_is_array(rstc)) {
998 reset_control_array_put(rstc_to_array(rstc));
1002 mutex_lock(&reset_list_mutex);
1003 __reset_control_put_internal(rstc);
1004 mutex_unlock(&reset_list_mutex);
1006 EXPORT_SYMBOL_GPL(reset_control_put);
1009 * reset_control_bulk_put - free the reset controllers
1010 * @num_rstcs: number of entries in rstcs array
1011 * @rstcs: array of struct reset_control_bulk_data with reset controls set
1013 void reset_control_bulk_put(int num_rstcs, struct reset_control_bulk_data *rstcs)
1015 mutex_lock(&reset_list_mutex);
1016 while (num_rstcs--) {
1017 if (IS_ERR_OR_NULL(rstcs[num_rstcs].rstc))
1019 __reset_control_put_internal(rstcs[num_rstcs].rstc);
1021 mutex_unlock(&reset_list_mutex);
1023 EXPORT_SYMBOL_GPL(reset_control_bulk_put);
1025 static void devm_reset_control_release(struct device *dev, void *res)
1027 reset_control_put(*(struct reset_control **)res);
1030 struct reset_control *__devm_reset_control_get(struct device *dev,
1031 const char *id, int index, bool shared,
1032 bool optional, bool acquired)
1034 struct reset_control **ptr, *rstc;
1036 ptr = devres_alloc(devm_reset_control_release, sizeof(*ptr),
1039 return ERR_PTR(-ENOMEM);
1041 rstc = __reset_control_get(dev, id, index, shared, optional, acquired);
1042 if (IS_ERR_OR_NULL(rstc)) {
1048 devres_add(dev, ptr);
1052 EXPORT_SYMBOL_GPL(__devm_reset_control_get);
1054 struct reset_control_bulk_devres {
1056 struct reset_control_bulk_data *rstcs;
1059 static void devm_reset_control_bulk_release(struct device *dev, void *res)
1061 struct reset_control_bulk_devres *devres = res;
1063 reset_control_bulk_put(devres->num_rstcs, devres->rstcs);
1066 int __devm_reset_control_bulk_get(struct device *dev, int num_rstcs,
1067 struct reset_control_bulk_data *rstcs,
1068 bool shared, bool optional, bool acquired)
1070 struct reset_control_bulk_devres *ptr;
1073 ptr = devres_alloc(devm_reset_control_bulk_release, sizeof(*ptr),
1078 ret = __reset_control_bulk_get(dev, num_rstcs, rstcs, shared, optional, acquired);
1084 ptr->num_rstcs = num_rstcs;
1086 devres_add(dev, ptr);
1090 EXPORT_SYMBOL_GPL(__devm_reset_control_bulk_get);
1093 * __device_reset - find reset controller associated with the device
1095 * @dev: device to be reset by the controller
1096 * @optional: whether it is optional to reset the device
1098 * Convenience wrapper for __reset_control_get() and reset_control_reset().
1099 * This is useful for the common case of devices with single, dedicated reset
1102 int __device_reset(struct device *dev, bool optional)
1104 struct reset_control *rstc;
1107 rstc = __reset_control_get(dev, NULL, 0, 0, optional, true);
1109 return PTR_ERR(rstc);
1111 ret = reset_control_reset(rstc);
1113 reset_control_put(rstc);
1117 EXPORT_SYMBOL_GPL(__device_reset);
1120 * APIs to manage an array of reset controls.
1124 * of_reset_control_get_count - Count number of resets available with a device
1126 * @node: device node that contains 'resets'.
1128 * Returns positive reset count on success, or error number on failure and
1129 * on count being zero.
1131 static int of_reset_control_get_count(struct device_node *node)
1138 count = of_count_phandle_with_args(node, "resets", "#reset-cells");
1146 * of_reset_control_array_get - Get a list of reset controls using
1149 * @np: device node for the device that requests the reset controls array
1150 * @shared: whether reset controls are shared or not
1151 * @optional: whether it is optional to get the reset controls
1152 * @acquired: only one reset control may be acquired for a given controller
1155 * Returns pointer to allocated reset_control on success or error on failure
1157 struct reset_control *
1158 of_reset_control_array_get(struct device_node *np, bool shared, bool optional,
1161 struct reset_control_array *resets;
1162 struct reset_control *rstc;
1165 num = of_reset_control_get_count(np);
1167 return optional ? NULL : ERR_PTR(num);
1169 resets = kzalloc(struct_size(resets, rstc, num), GFP_KERNEL);
1171 return ERR_PTR(-ENOMEM);
1173 for (i = 0; i < num; i++) {
1174 rstc = __of_reset_control_get(np, NULL, i, shared, optional,
1178 resets->rstc[i] = rstc;
1180 resets->num_rstcs = num;
1181 resets->base.array = true;
1183 return &resets->base;
1186 mutex_lock(&reset_list_mutex);
1188 __reset_control_put_internal(resets->rstc[i]);
1189 mutex_unlock(&reset_list_mutex);
1195 EXPORT_SYMBOL_GPL(of_reset_control_array_get);
1198 * devm_reset_control_array_get - Resource managed reset control array get
1200 * @dev: device that requests the list of reset controls
1201 * @shared: whether reset controls are shared or not
1202 * @optional: whether it is optional to get the reset controls
1204 * The reset control array APIs are intended for a list of resets
1205 * that just have to be asserted or deasserted, without any
1206 * requirements on the order.
1208 * Returns pointer to allocated reset_control on success or error on failure
1210 struct reset_control *
1211 devm_reset_control_array_get(struct device *dev, bool shared, bool optional)
1213 struct reset_control **ptr, *rstc;
1215 ptr = devres_alloc(devm_reset_control_release, sizeof(*ptr),
1218 return ERR_PTR(-ENOMEM);
1220 rstc = of_reset_control_array_get(dev->of_node, shared, optional, true);
1221 if (IS_ERR_OR_NULL(rstc)) {
1227 devres_add(dev, ptr);
1231 EXPORT_SYMBOL_GPL(devm_reset_control_array_get);
1233 static int reset_control_get_count_from_lookup(struct device *dev)
1235 const struct reset_control_lookup *lookup;
1242 dev_id = dev_name(dev);
1243 mutex_lock(&reset_lookup_mutex);
1245 list_for_each_entry(lookup, &reset_lookup_list, list) {
1246 if (!strcmp(lookup->dev_id, dev_id))
1250 mutex_unlock(&reset_lookup_mutex);
1259 * reset_control_get_count - Count number of resets available with a device
1261 * @dev: device for which to return the number of resets
1263 * Returns positive reset count on success, or error number on failure and
1264 * on count being zero.
1266 int reset_control_get_count(struct device *dev)
1269 return of_reset_control_get_count(dev->of_node);
1271 return reset_control_get_count_from_lookup(dev);
1273 EXPORT_SYMBOL_GPL(reset_control_get_count);