1 // SPDX-License-Identifier: GPL-2.0-or-later
17 #include <linux/reset-controller.h>
27  * struct reset_control - a reset control
39  *                   only used for shared resets, which means that the value
55  * struct reset_control_array - an array of reset controls
68 	if (rcdev->dev)  in rcdev_name()
69 		return dev_name(rcdev->dev);  in rcdev_name()
71 	if (rcdev->of_node)  in rcdev_name()
72 		return rcdev->of_node->full_name;  in rcdev_name()
78  * of_reset_simple_xlate - translate reset_spec to the reset line number
90 	if (reset_spec->args[0] >= rcdev->nr_resets)  in of_reset_simple_xlate()
91 		return -EINVAL;  in of_reset_simple_xlate()
93 	return reset_spec->args[0];  in of_reset_simple_xlate()
97  * reset_controller_register - register a reset controller device
102 	if (!rcdev->of_xlate) {  in reset_controller_register()
103 		rcdev->of_reset_n_cells = 1;  in reset_controller_register()
104 		rcdev->of_xlate = of_reset_simple_xlate;  in reset_controller_register()
107 	INIT_LIST_HEAD(&rcdev->reset_control_head);  in reset_controller_register()
110 	list_add(&rcdev->list, &reset_controller_list);  in reset_controller_register()
118  * reset_controller_unregister - unregister a reset controller device
124 	list_del(&rcdev->list);  in reset_controller_unregister()
135  * devm_reset_controller_register - resource managed reset_controller_register()
152 		return -ENOMEM;  in devm_reset_controller_register()
168  * reset_controller_add_lookup - register a set of lookup entries
182 		if (!entry->dev_id || !entry->provider) {  in reset_controller_add_lookup()
188 		list_add_tail(&entry->list, &reset_lookup_list);  in reset_controller_add_lookup()
199 static int reset_control_array_reset(struct reset_control_array *resets)  in reset_control_array_reset()  argument
203 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_reset()
204 		ret = reset_control_reset(resets->rstc[i]);  in reset_control_array_reset()
212 static int reset_control_array_rearm(struct reset_control_array *resets)  in reset_control_array_rearm()  argument
217 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_rearm()
218 		rstc = resets->rstc[i];  in reset_control_array_rearm()
224 			return -EINVAL;  in reset_control_array_rearm()
226 		if (rstc->shared) {  in reset_control_array_rearm()
227 			if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))  in reset_control_array_rearm()
228 				return -EINVAL;  in reset_control_array_rearm()
230 			if (!rstc->acquired)  in reset_control_array_rearm()
231 				return -EPERM;  in reset_control_array_rearm()
235 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_rearm()
236 		rstc = resets->rstc[i];  in reset_control_array_rearm()
238 		if (rstc && rstc->shared)  in reset_control_array_rearm()
239 			WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);  in reset_control_array_rearm()
245 static int reset_control_array_assert(struct reset_control_array *resets)  in reset_control_array_assert()  argument
249 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_assert()
250 		ret = reset_control_assert(resets->rstc[i]);  in reset_control_array_assert()
258 	while (i--)  in reset_control_array_assert()
259 		reset_control_deassert(resets->rstc[i]);  in reset_control_array_assert()
263 static int reset_control_array_deassert(struct reset_control_array *resets)  in reset_control_array_deassert()  argument
267 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_deassert()
268 		ret = reset_control_deassert(resets->rstc[i]);  in reset_control_array_deassert()
276 	while (i--)  in reset_control_array_deassert()
277 		reset_control_assert(resets->rstc[i]);  in reset_control_array_deassert()
281 static int reset_control_array_acquire(struct reset_control_array *resets)  in reset_control_array_acquire()  argument
286 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_acquire()
287 		err = reset_control_acquire(resets->rstc[i]);  in reset_control_array_acquire()
295 	while (i--)  in reset_control_array_acquire()
296 		reset_control_release(resets->rstc[i]);  in reset_control_array_acquire()
301 static void reset_control_array_release(struct reset_control_array *resets)  in reset_control_array_release()  argument
305 	for (i = 0; i < resets->num_rstcs; i++)  in reset_control_array_release()
306 		reset_control_release(resets->rstc[i]);  in reset_control_array_release()
311 	return rstc->array;  in reset_control_is_array()
315  * reset_control_reset - reset the controlled device
320  * a no-op.
335 		return -EINVAL;  in reset_control_reset()
340 	if (!rstc->rcdev->ops->reset)  in reset_control_reset()
341 		return -ENOTSUPP;  in reset_control_reset()
343 	if (rstc->shared) {  in reset_control_reset()
344 		if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))  in reset_control_reset()
345 			return -EINVAL;  in reset_control_reset()
347 		if (atomic_inc_return(&rstc->triggered_count) != 1)  in reset_control_reset()
350 		if (!rstc->acquired)  in reset_control_reset()
351 			return -EPERM;  in reset_control_reset()
354 	ret = rstc->rcdev->ops->reset(rstc->rcdev, rstc->id);  in reset_control_reset()
355 	if (rstc->shared && ret)  in reset_control_reset()
356 		atomic_dec(&rstc->triggered_count);  in reset_control_reset()
363  * reset_control_bulk_reset - reset the controlled devices in order
387  * reset_control_rearm - allow shared reset line to be re-triggered"
407 		return -EINVAL;  in reset_control_rearm()
412 	if (rstc->shared) {  in reset_control_rearm()
413 		if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))  in reset_control_rearm()
414 			return -EINVAL;  in reset_control_rearm()
416 		WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);  in reset_control_rearm()
418 		if (!rstc->acquired)  in reset_control_rearm()
419 			return -EPERM;  in reset_control_rearm()
427  * reset_control_assert - asserts the reset line
448 		return -EINVAL;  in reset_control_assert()
453 	if (rstc->shared) {  in reset_control_assert()
454 		if (WARN_ON(atomic_read(&rstc->triggered_count) != 0))  in reset_control_assert()
455 			return -EINVAL;  in reset_control_assert()
457 		if (WARN_ON(atomic_read(&rstc->deassert_count) == 0))  in reset_control_assert()
458 			return -EINVAL;  in reset_control_assert()
460 		if (atomic_dec_return(&rstc->deassert_count) != 0)  in reset_control_assert()
467 		if (!rstc->rcdev->ops->assert)  in reset_control_assert()
475 		if (!rstc->rcdev->ops->assert)  in reset_control_assert()
476 			return -ENOTSUPP;  in reset_control_assert()
478 		if (!rstc->acquired) {  in reset_control_assert()
480 			     rcdev_name(rstc->rcdev), rstc->id);  in reset_control_assert()
481 			return -EPERM;  in reset_control_assert()
485 	return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id);  in reset_control_assert()
490  * reset_control_bulk_assert - asserts the reset lines in order
495  * If an assertion fails, already asserted resets are deasserted again.
513 	while (i--)  in reset_control_bulk_assert()
520  * reset_control_deassert - deasserts the reset line
536 		return -EINVAL;  in reset_control_deassert()
541 	if (rstc->shared) {  in reset_control_deassert()
542 		if (WARN_ON(atomic_read(&rstc->triggered_count) != 0))  in reset_control_deassert()
543 			return -EINVAL;  in reset_control_deassert()
545 		if (atomic_inc_return(&rstc->deassert_count) != 1)  in reset_control_deassert()
548 		if (!rstc->acquired) {  in reset_control_deassert()
550 			     rcdev_name(rstc->rcdev), rstc->id);  in reset_control_deassert()
551 			return -EPERM;  in reset_control_deassert()
557 	 * that it handles self-deasserting reset lines via .reset(). In that  in reset_control_deassert()
560 	 * return -ENOTSUPP.  in reset_control_deassert()
562 	if (!rstc->rcdev->ops->deassert)  in reset_control_deassert()
565 	return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id);  in reset_control_deassert()
570  * reset_control_bulk_deassert - deasserts the reset lines in reverse order
575  * If a deassertion fails, already deasserted resets are asserted again.
584 	for (i = num_rstcs - 1; i >= 0; i--) {  in reset_control_bulk_deassert()
600  * reset_control_status - returns a negative errno if not supported, a
611 		return -EINVAL;  in reset_control_status()
613 	if (rstc->rcdev->ops->status)  in reset_control_status()
614 		return rstc->rcdev->ops->status(rstc->rcdev, rstc->id);  in reset_control_status()
616 	return -ENOTSUPP;  in reset_control_status()
621  * reset_control_acquire() - acquires a reset control for exclusive use
625  * that exclusive resets are requested as acquired by default. In order for a
648 		return -EINVAL;  in reset_control_acquire()
655 	if (rstc->acquired) {  in reset_control_acquire()
660 	list_for_each_entry(rc, &rstc->rcdev->reset_control_head, list) {  in reset_control_acquire()
661 		if (rstc != rc && rstc->id == rc->id) {  in reset_control_acquire()
662 			if (rc->acquired) {  in reset_control_acquire()
664 				return -EBUSY;  in reset_control_acquire()
669 	rstc->acquired = true;  in reset_control_acquire()
677  * reset_control_bulk_acquire - acquires reset controls for exclusive use
700 	while (i--)  in reset_control_bulk_acquire()
707  * reset_control_release() - releases exclusive access to a reset control
724 		rstc->acquired = false;  in reset_control_release()
729  * reset_control_bulk_release() - releases exclusive access to reset controls
756 	list_for_each_entry(rstc, &rcdev->reset_control_head, list) {  in __reset_control_get_internal()
757 		if (rstc->id == index) {  in __reset_control_get_internal()
763 			if (!rstc->shared && !shared && !acquired)  in __reset_control_get_internal()
766 			if (WARN_ON(!rstc->shared || !shared))  in __reset_control_get_internal()
767 				return ERR_PTR(-EBUSY);  in __reset_control_get_internal()
769 			kref_get(&rstc->refcnt);  in __reset_control_get_internal()
776 		return ERR_PTR(-ENOMEM);  in __reset_control_get_internal()
778 	if (!try_module_get(rcdev->owner)) {  in __reset_control_get_internal()
780 		return ERR_PTR(-ENODEV);  in __reset_control_get_internal()
783 	rstc->rcdev = rcdev;  in __reset_control_get_internal()
784 	list_add(&rstc->list, &rcdev->reset_control_head);  in __reset_control_get_internal()
785 	rstc->id = index;  in __reset_control_get_internal()
786 	kref_init(&rstc->refcnt);  in __reset_control_get_internal()
787 	rstc->acquired = acquired;  in __reset_control_get_internal()
788 	rstc->shared = shared;  in __reset_control_get_internal()
800 	module_put(rstc->rcdev->owner);  in __reset_control_release()
802 	list_del(&rstc->list);  in __reset_control_release()
813 	kref_put(&rstc->refcnt, __reset_control_release);  in __reset_control_put_internal()
827 		return ERR_PTR(-EINVAL);  in __of_reset_control_get()
831 						 "reset-names", id);  in __of_reset_control_get()
832 		if (index == -EILSEQ)  in __of_reset_control_get()
835 			return optional ? NULL : ERR_PTR(-ENOENT);  in __of_reset_control_get()
838 	ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",  in __of_reset_control_get()
840 	if (ret == -EINVAL)  in __of_reset_control_get()
848 		if (args.np == r->of_node) {  in __of_reset_control_get()
855 		rstc = ERR_PTR(-EPROBE_DEFER);  in __of_reset_control_get()
859 	if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) {  in __of_reset_control_get()
860 		rstc = ERR_PTR(-EINVAL);  in __of_reset_control_get()
864 	rstc_id = rcdev->of_xlate(rcdev, &args);  in __of_reset_control_get()
889 		if (!rcdev->dev)  in __reset_controller_by_name()
892 		if (!strcmp(name, dev_name(rcdev->dev)))  in __reset_controller_by_name()
911 		if (strcmp(lookup->dev_id, dev_id))  in __reset_control_get_from_lookup()
914 		if ((!con_id && !lookup->con_id) ||  in __reset_control_get_from_lookup()
915 		    ((con_id && lookup->con_id) &&  in __reset_control_get_from_lookup()
916 		     !strcmp(con_id, lookup->con_id))) {  in __reset_control_get_from_lookup()
918 			rcdev = __reset_controller_by_name(lookup->provider);  in __reset_control_get_from_lookup()
923 				return ERR_PTR(-EPROBE_DEFER);  in __reset_control_get_from_lookup()
927 							    lookup->index,  in __reset_control_get_from_lookup()
937 		return optional ? NULL : ERR_PTR(-ENOENT);  in __reset_control_get_from_lookup()
947 		return ERR_PTR(-EINVAL);  in __reset_control_get()
949 	if (dev->of_node)  in __reset_control_get()
950 		return __of_reset_control_get(dev->of_node, id, index, shared,  in __reset_control_get()
977 	while (i--)  in __reset_control_bulk_get()
984 static void reset_control_array_put(struct reset_control_array *resets)  in reset_control_array_put()  argument
989 	for (i = 0; i < resets->num_rstcs; i++)  in reset_control_array_put()
990 		__reset_control_put_internal(resets->rstc[i]);  in reset_control_array_put()
992 	kfree(resets);  in reset_control_array_put()
996  * reset_control_put - free the reset controller
1016  * reset_control_bulk_put - free the reset controllers
1023 	while (num_rstcs--)  in reset_control_bulk_put()
1043 		return ERR_PTR(-ENOMEM);  in __devm_reset_control_get()
1067 	reset_control_bulk_put(devres->num_rstcs, devres->rstcs);  in devm_reset_control_bulk_release()
1080 		return -ENOMEM;  in __devm_reset_control_bulk_get()
1088 	ptr->num_rstcs = num_rstcs;  in __devm_reset_control_bulk_get()
1089 	ptr->rstcs = rstcs;  in __devm_reset_control_bulk_get()
1097  * __device_reset - find reset controller associated with the device
1116 			return optional ? 0 : -ENOENT;  in __device_reset()
1119 			return -EIO;  in __device_reset()
1140  * of_reset_control_get_count - Count number of resets available with a device
1142  * @node: device node that contains 'resets'.
1152 		return -EINVAL;  in of_reset_control_get_count()
1154 	count = of_count_phandle_with_args(node, "resets", "#reset-cells");  in of_reset_control_get_count()
1156 		count = -ENOENT;  in of_reset_control_get_count()
1162  * of_reset_control_array_get - Get a list of reset controls using
1177 	struct reset_control_array *resets;  in of_reset_control_array_get()  local
1185 	resets = kzalloc(struct_size(resets, rstc, num), GFP_KERNEL);  in of_reset_control_array_get()
1186 	if (!resets)  in of_reset_control_array_get()
1187 		return ERR_PTR(-ENOMEM);  in of_reset_control_array_get()
1194 		resets->rstc[i] = rstc;  in of_reset_control_array_get()
1196 	resets->num_rstcs = num;  in of_reset_control_array_get()
1197 	resets->base.array = true;  in of_reset_control_array_get()
1199 	return &resets->base;  in of_reset_control_array_get()
1203 	while (--i >= 0)  in of_reset_control_array_get()
1204 		__reset_control_put_internal(resets->rstc[i]);  in of_reset_control_array_get()
1207 	kfree(resets);  in of_reset_control_array_get()
1214  * devm_reset_control_array_get - Resource managed reset control array get
1220  * The reset control array APIs are intended for a list of resets
1234 		return ERR_PTR(-ENOMEM);  in devm_reset_control_array_get()
1236 	rstc = of_reset_control_array_get(dev->of_node, shared, optional, true);  in devm_reset_control_array_get()
1256 		return -EINVAL;  in reset_control_get_count_from_lookup()
1262 		if (!strcmp(lookup->dev_id, dev_id))  in reset_control_get_count_from_lookup()
1269 		count = -ENOENT;  in reset_control_get_count_from_lookup()
1275  * reset_control_get_count - Count number of resets available with a device
1277  * @dev: device for which to return the number of resets
1284 	if (dev->of_node)  in reset_control_get_count()
1285 		return of_reset_control_get_count(dev->of_node);  in reset_control_get_count()