1 // SPDX-License-Identifier: GPL-2.0-or-later
16 #include <linux/reset-controller.h>
26  * struct reset_control - a reset control
54  * struct reset_control_array - an array of reset controls
67 	if (rcdev->dev)  in rcdev_name()
68 		return dev_name(rcdev->dev);  in rcdev_name()
70 	if (rcdev->of_node)  in rcdev_name()
71 		return rcdev->of_node->full_name;  in rcdev_name()
77  * of_reset_simple_xlate - translate reset_spec to the reset line number
89 	if (reset_spec->args[0] >= rcdev->nr_resets)  in of_reset_simple_xlate()
90 		return -EINVAL;  in of_reset_simple_xlate()
92 	return reset_spec->args[0];  in of_reset_simple_xlate()
96  * reset_controller_register - register a reset controller device
101 	if (!rcdev->of_xlate) {  in reset_controller_register()
102 		rcdev->of_reset_n_cells = 1;  in reset_controller_register()
103 		rcdev->of_xlate = of_reset_simple_xlate;  in reset_controller_register()
106 	INIT_LIST_HEAD(&rcdev->reset_control_head);  in reset_controller_register()
109 	list_add(&rcdev->list, &reset_controller_list);  in reset_controller_register()
117  * reset_controller_unregister - unregister a reset controller device
123 	list_del(&rcdev->list);  in reset_controller_unregister()
134  * devm_reset_controller_register - resource managed reset_controller_register()
151 		return -ENOMEM;  in devm_reset_controller_register()
167  * reset_controller_add_lookup - register a set of lookup entries
181 		if (!entry->dev_id || !entry->provider) {  in reset_controller_add_lookup()
187 		list_add_tail(&entry->list, &reset_lookup_list);  in reset_controller_add_lookup()
202 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_reset()
203 		ret = reset_control_reset(resets->rstc[i]);  in reset_control_array_reset()
216 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_rearm()
217 		rstc = resets->rstc[i];  in reset_control_array_rearm()
223 			return -EINVAL;  in reset_control_array_rearm()
225 		if (rstc->shared) {  in reset_control_array_rearm()
226 			if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))  in reset_control_array_rearm()
227 				return -EINVAL;  in reset_control_array_rearm()
229 			if (!rstc->acquired)  in reset_control_array_rearm()
230 				return -EPERM;  in reset_control_array_rearm()
234 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_rearm()
235 		rstc = resets->rstc[i];  in reset_control_array_rearm()
237 		if (rstc && rstc->shared)  in reset_control_array_rearm()
238 			WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);  in reset_control_array_rearm()
248 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_assert()
249 		ret = reset_control_assert(resets->rstc[i]);  in reset_control_array_assert()
257 	while (i--)  in reset_control_array_assert()
258 		reset_control_deassert(resets->rstc[i]);  in reset_control_array_assert()
266 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_deassert()
267 		ret = reset_control_deassert(resets->rstc[i]);  in reset_control_array_deassert()
275 	while (i--)  in reset_control_array_deassert()
276 		reset_control_assert(resets->rstc[i]);  in reset_control_array_deassert()
285 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_acquire()
286 		err = reset_control_acquire(resets->rstc[i]);  in reset_control_array_acquire()
294 	while (i--)  in reset_control_array_acquire()
295 		reset_control_release(resets->rstc[i]);  in reset_control_array_acquire()
304 	for (i = 0; i < resets->num_rstcs; i++)  in reset_control_array_release()
305 		reset_control_release(resets->rstc[i]);  in reset_control_array_release()
310 	return rstc->array;  in reset_control_is_array()
314  * reset_control_reset - reset the controlled device
319  * a no-op.
320  * Consumers must not use reset_control_(de)assert on shared reset lines when
334 		return -EINVAL;  in reset_control_reset()
339 	if (!rstc->rcdev->ops->reset)  in reset_control_reset()
340 		return -ENOTSUPP;  in reset_control_reset()
342 	if (rstc->shared) {  in reset_control_reset()
343 		if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))  in reset_control_reset()
344 			return -EINVAL;  in reset_control_reset()
346 		if (atomic_inc_return(&rstc->triggered_count) != 1)  in reset_control_reset()
349 		if (!rstc->acquired)  in reset_control_reset()
350 			return -EPERM;  in reset_control_reset()
353 	ret = rstc->rcdev->ops->reset(rstc->rcdev, rstc->id);  in reset_control_reset()
354 	if (rstc->shared && ret)  in reset_control_reset()
355 		atomic_dec(&rstc->triggered_count);  in reset_control_reset()
362  * reset_control_bulk_reset - reset the controlled devices in order
386  * reset_control_rearm - allow shared reset line to be re-triggered"
395  * Consumers must not use reset_control_(de)assert on shared reset lines when
406 		return -EINVAL;  in reset_control_rearm()
411 	if (rstc->shared) {  in reset_control_rearm()
412 		if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))  in reset_control_rearm()
413 			return -EINVAL;  in reset_control_rearm()
415 		WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);  in reset_control_rearm()
417 		if (!rstc->acquired)  in reset_control_rearm()
418 			return -EPERM;  in reset_control_rearm()
426  * reset_control_assert - asserts the reset line
430  * will be asserted. When called on a shared reset controller the line may
436  * reset_control_(de)assert has been used.
447 		return -EINVAL;  in reset_control_assert()
452 	if (rstc->shared) {  in reset_control_assert()
453 		if (WARN_ON(atomic_read(&rstc->triggered_count) != 0))  in reset_control_assert()
454 			return -EINVAL;  in reset_control_assert()
456 		if (WARN_ON(atomic_read(&rstc->deassert_count) == 0))  in reset_control_assert()
457 			return -EINVAL;  in reset_control_assert()
459 		if (atomic_dec_return(&rstc->deassert_count) != 0)  in reset_control_assert()
466 		if (!rstc->rcdev->ops->assert)  in reset_control_assert()
471 		 * is no way to guarantee that the reset line is asserted after  in reset_control_assert()
474 		if (!rstc->rcdev->ops->assert)  in reset_control_assert()
475 			return -ENOTSUPP;  in reset_control_assert()
477 		if (!rstc->acquired) {  in reset_control_assert()
479 			     rcdev_name(rstc->rcdev), rstc->id);  in reset_control_assert()
480 			return -EPERM;  in reset_control_assert()
484 	return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id);  in reset_control_assert()
489  * reset_control_bulk_assert - asserts the reset lines in order
494  * If an assertion fails, already asserted resets are deasserted again.
512 	while (i--)  in reset_control_bulk_assert()
519  * reset_control_deassert - deasserts the reset line
524  * reset_control_(de)assert has been used.
535 		return -EINVAL;  in reset_control_deassert()
540 	if (rstc->shared) {  in reset_control_deassert()
541 		if (WARN_ON(atomic_read(&rstc->triggered_count) != 0))  in reset_control_deassert()
542 			return -EINVAL;  in reset_control_deassert()
544 		if (atomic_inc_return(&rstc->deassert_count) != 1)  in reset_control_deassert()
547 		if (!rstc->acquired) {  in reset_control_deassert()
549 			     rcdev_name(rstc->rcdev), rstc->id);  in reset_control_deassert()
550 			return -EPERM;  in reset_control_deassert()
556 	 * that it handles self-deasserting reset lines via .reset(). In that  in reset_control_deassert()
559 	 * return -ENOTSUPP.  in reset_control_deassert()
561 	if (!rstc->rcdev->ops->deassert)  in reset_control_deassert()
564 	return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id);  in reset_control_deassert()
569  * reset_control_bulk_deassert - deasserts the reset lines in reverse order
574  * If a deassertion fails, already deasserted resets are asserted again.
583 	for (i = num_rstcs - 1; i >= 0; i--) {  in 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).
610 		return -EINVAL;  in reset_control_status()
612 	if (rstc->rcdev->ops->status)  in reset_control_status()
613 		return rstc->rcdev->ops->status(rstc->rcdev, rstc->id);  in reset_control_status()
615 	return -ENOTSUPP;  in reset_control_status()
620  * reset_control_acquire() - acquires a reset control for exclusive use
647 		return -EINVAL;  in reset_control_acquire()
654 	if (rstc->acquired) {  in reset_control_acquire()
659 	list_for_each_entry(rc, &rstc->rcdev->reset_control_head, list) {  in reset_control_acquire()
660 		if (rstc != rc && rstc->id == rc->id) {  in reset_control_acquire()
661 			if (rc->acquired) {  in reset_control_acquire()
663 				return -EBUSY;  in reset_control_acquire()
668 	rstc->acquired = true;  in reset_control_acquire()
676  * reset_control_bulk_acquire - acquires reset controls for exclusive use
699 	while (i--)  in reset_control_bulk_acquire()
706  * reset_control_release() - releases exclusive access to a reset control
723 		rstc->acquired = false;  in reset_control_release()
728  * reset_control_bulk_release() - releases exclusive access to reset controls
755 	list_for_each_entry(rstc, &rcdev->reset_control_head, list) {  in __reset_control_get_internal()
756 		if (rstc->id == index) {  in __reset_control_get_internal()
762 			if (!rstc->shared && !shared && !acquired)  in __reset_control_get_internal()
765 			if (WARN_ON(!rstc->shared || !shared))  in __reset_control_get_internal()
766 				return ERR_PTR(-EBUSY);  in __reset_control_get_internal()
768 			kref_get(&rstc->refcnt);  in __reset_control_get_internal()
775 		return ERR_PTR(-ENOMEM);  in __reset_control_get_internal()
777 	if (!try_module_get(rcdev->owner)) {  in __reset_control_get_internal()
779 		return ERR_PTR(-ENODEV);  in __reset_control_get_internal()
782 	rstc->rcdev = rcdev;  in __reset_control_get_internal()
783 	list_add(&rstc->list, &rcdev->reset_control_head);  in __reset_control_get_internal()
784 	rstc->id = index;  in __reset_control_get_internal()
785 	kref_init(&rstc->refcnt);  in __reset_control_get_internal()
786 	rstc->acquired = acquired;  in __reset_control_get_internal()
787 	rstc->shared = shared;  in __reset_control_get_internal()
799 	module_put(rstc->rcdev->owner);  in __reset_control_release()
801 	list_del(&rstc->list);  in __reset_control_release()
809 	kref_put(&rstc->refcnt, __reset_control_release);  in __reset_control_put_internal()
823 		return ERR_PTR(-EINVAL);  in __of_reset_control_get()
827 						 "reset-names", id);  in __of_reset_control_get()
828 		if (index == -EILSEQ)  in __of_reset_control_get()
831 			return optional ? NULL : ERR_PTR(-ENOENT);  in __of_reset_control_get()
834 	ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",  in __of_reset_control_get()
836 	if (ret == -EINVAL)  in __of_reset_control_get()
844 		if (args.np == r->of_node) {  in __of_reset_control_get()
851 		rstc = ERR_PTR(-EPROBE_DEFER);  in __of_reset_control_get()
855 	if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) {  in __of_reset_control_get()
856 		rstc = ERR_PTR(-EINVAL);  in __of_reset_control_get()
860 	rstc_id = rcdev->of_xlate(rcdev, &args);  in __of_reset_control_get()
885 		if (!rcdev->dev)  in __reset_controller_by_name()
888 		if (!strcmp(name, dev_name(rcdev->dev)))  in __reset_controller_by_name()
907 		if (strcmp(lookup->dev_id, dev_id))  in __reset_control_get_from_lookup()
910 		if ((!con_id && !lookup->con_id) ||  in __reset_control_get_from_lookup()
911 		    ((con_id && lookup->con_id) &&  in __reset_control_get_from_lookup()
912 		     !strcmp(con_id, lookup->con_id))) {  in __reset_control_get_from_lookup()
914 			rcdev = __reset_controller_by_name(lookup->provider);  in __reset_control_get_from_lookup()
919 				return ERR_PTR(-EPROBE_DEFER);  in __reset_control_get_from_lookup()
923 							    lookup->index,  in __reset_control_get_from_lookup()
933 		return optional ? NULL : ERR_PTR(-ENOENT);  in __reset_control_get_from_lookup()
943 		return ERR_PTR(-EINVAL);  in __reset_control_get()
945 	if (dev->of_node)  in __reset_control_get()
946 		return __of_reset_control_get(dev->of_node, id, index, shared,  in __reset_control_get()
973 	while (i--)  in __reset_control_bulk_get()
985 	for (i = 0; i < resets->num_rstcs; i++)  in reset_control_array_put()
986 		__reset_control_put_internal(resets->rstc[i]);  in reset_control_array_put()
992  * reset_control_put - free the reset controller
1012  * reset_control_bulk_put - free the reset controllers
1019 	while (num_rstcs--) {  in reset_control_bulk_put()
1042 		return ERR_PTR(-ENOMEM);  in __devm_reset_control_get()
1066 	reset_control_bulk_put(devres->num_rstcs, devres->rstcs);  in devm_reset_control_bulk_release()
1079 		return -ENOMEM;  in __devm_reset_control_bulk_get()
1087 	ptr->num_rstcs = num_rstcs;  in __devm_reset_control_bulk_get()
1088 	ptr->rstcs = rstcs;  in __devm_reset_control_bulk_get()
1096  * __device_reset - find reset controller associated with the device
1127  * of_reset_control_get_count - Count number of resets available with a device
1139 		return -EINVAL;  in of_reset_control_get_count()
1141 	count = of_count_phandle_with_args(node, "resets", "#reset-cells");  in of_reset_control_get_count()
1143 		count = -ENOENT;  in of_reset_control_get_count()
1149  * of_reset_control_array_get - Get a list of reset controls using
1174 		return ERR_PTR(-ENOMEM);  in of_reset_control_array_get()
1181 		resets->rstc[i] = rstc;  in of_reset_control_array_get()
1183 	resets->num_rstcs = num;  in of_reset_control_array_get()
1184 	resets->base.array = true;  in of_reset_control_array_get()
1186 	return &resets->base;  in of_reset_control_array_get()
1190 	while (--i >= 0)  in of_reset_control_array_get()
1191 		__reset_control_put_internal(resets->rstc[i]);  in of_reset_control_array_get()
1201  * devm_reset_control_array_get - Resource managed reset control array get
1208  * that just have to be asserted or deasserted, without any
1221 		return ERR_PTR(-ENOMEM);  in devm_reset_control_array_get()
1223 	rstc = of_reset_control_array_get(dev->of_node, shared, optional, true);  in devm_reset_control_array_get()
1243 		return -EINVAL;  in reset_control_get_count_from_lookup()
1249 		if (!strcmp(lookup->dev_id, dev_id))  in reset_control_get_count_from_lookup()
1256 		count = -ENOENT;  in reset_control_get_count_from_lookup()
1262  * reset_control_get_count - Count number of resets available with a device
1271 	if (dev->of_node)  in reset_control_get_count()
1272 		return of_reset_control_get_count(dev->of_node);  in reset_control_get_count()