1 // SPDX-License-Identifier: GPL-2.0-or-later
22 #include <linux/reset-controller.h>
37  * struct reset_control - a reset control
65  * struct reset_control_array - an array of reset controls
77  * struct reset_gpio_lookup - lookup key for ad-hoc created reset-gpio devices
88 	if (rcdev->dev)  in rcdev_name()
89 		return dev_name(rcdev->dev);  in rcdev_name()
91 	if (rcdev->of_node)  in rcdev_name()
92 		return rcdev->of_node->full_name;  in rcdev_name()
94 	if (rcdev->of_args)  in rcdev_name()
95 		return rcdev->of_args->np->full_name;  in rcdev_name()
101  * of_reset_simple_xlate - translate reset_spec to the reset line number
113 	if (reset_spec->args[0] >= rcdev->nr_resets)  in of_reset_simple_xlate()
114 		return -EINVAL;  in of_reset_simple_xlate()
116 	return reset_spec->args[0];  in of_reset_simple_xlate()
120  * reset_controller_register - register a reset controller device
125 	if (rcdev->of_node && rcdev->of_args)  in reset_controller_register()
126 		return -EINVAL;  in reset_controller_register()
128 	if (!rcdev->of_xlate) {  in reset_controller_register()
129 		rcdev->of_reset_n_cells = 1;  in reset_controller_register()
130 		rcdev->of_xlate = of_reset_simple_xlate;  in reset_controller_register()
133 	INIT_LIST_HEAD(&rcdev->reset_control_head);  in reset_controller_register()
136 	list_add(&rcdev->list, &reset_controller_list);  in reset_controller_register()
144  * reset_controller_unregister - unregister a reset controller device
150 	list_del(&rcdev->list);  in reset_controller_unregister()
161  * devm_reset_controller_register - resource managed reset_controller_register()
178 		return -ENOMEM;  in devm_reset_controller_register()
194  * reset_controller_add_lookup - register a set of lookup entries
208 		if (!entry->dev_id || !entry->provider) {  in reset_controller_add_lookup()
214 		list_add_tail(&entry->list, &reset_lookup_list);  in reset_controller_add_lookup()
229 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_reset()
230 		ret = reset_control_reset(resets->rstc[i]);  in reset_control_array_reset()
243 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_rearm()
244 		rstc = resets->rstc[i];  in reset_control_array_rearm()
250 			return -EINVAL;  in reset_control_array_rearm()
252 		if (rstc->shared) {  in reset_control_array_rearm()
253 			if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))  in reset_control_array_rearm()
254 				return -EINVAL;  in reset_control_array_rearm()
256 			if (!rstc->acquired)  in reset_control_array_rearm()
257 				return -EPERM;  in reset_control_array_rearm()
261 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_rearm()
262 		rstc = resets->rstc[i];  in reset_control_array_rearm()
264 		if (rstc && rstc->shared)  in reset_control_array_rearm()
265 			WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);  in reset_control_array_rearm()
275 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_assert()
276 		ret = reset_control_assert(resets->rstc[i]);  in reset_control_array_assert()
284 	while (i--)  in reset_control_array_assert()
285 		reset_control_deassert(resets->rstc[i]);  in reset_control_array_assert()
293 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_deassert()
294 		ret = reset_control_deassert(resets->rstc[i]);  in reset_control_array_deassert()
302 	while (i--)  in reset_control_array_deassert()
303 		reset_control_assert(resets->rstc[i]);  in reset_control_array_deassert()
312 	for (i = 0; i < resets->num_rstcs; i++) {  in reset_control_array_acquire()
313 		err = reset_control_acquire(resets->rstc[i]);  in reset_control_array_acquire()
321 	while (i--)  in reset_control_array_acquire()
322 		reset_control_release(resets->rstc[i]);  in reset_control_array_acquire()
331 	for (i = 0; i < resets->num_rstcs; i++)  in reset_control_array_release()
332 		reset_control_release(resets->rstc[i]);  in reset_control_array_release()
337 	return rstc->array;  in reset_control_is_array()
341  * reset_control_reset - reset the controlled device
346  * a no-op.
347  * Consumers must not use reset_control_(de)assert on shared reset lines when
361 		return -EINVAL;  in reset_control_reset()
366 	if (!rstc->rcdev->ops->reset)  in reset_control_reset()
367 		return -ENOTSUPP;  in reset_control_reset()
369 	if (rstc->shared) {  in reset_control_reset()
370 		if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))  in reset_control_reset()
371 			return -EINVAL;  in reset_control_reset()
373 		if (atomic_inc_return(&rstc->triggered_count) != 1)  in reset_control_reset()
376 		if (!rstc->acquired)  in reset_control_reset()
377 			return -EPERM;  in reset_control_reset()
380 	ret = rstc->rcdev->ops->reset(rstc->rcdev, rstc->id);  in reset_control_reset()
381 	if (rstc->shared && ret)  in reset_control_reset()
382 		atomic_dec(&rstc->triggered_count);  in reset_control_reset()
389  * reset_control_bulk_reset - reset the controlled devices in order
413  * reset_control_rearm - allow shared reset line to be re-triggered"
422  * Consumers must not use reset_control_(de)assert on shared reset lines when
433 		return -EINVAL;  in reset_control_rearm()
438 	if (rstc->shared) {  in reset_control_rearm()
439 		if (WARN_ON(atomic_read(&rstc->deassert_count) != 0))  in reset_control_rearm()
440 			return -EINVAL;  in reset_control_rearm()
442 		WARN_ON(atomic_dec_return(&rstc->triggered_count) < 0);  in reset_control_rearm()
444 		if (!rstc->acquired)  in reset_control_rearm()
445 			return -EPERM;  in reset_control_rearm()
453  * reset_control_assert - asserts the reset line
463  * reset_control_(de)assert has been used.
474 		return -EINVAL;  in reset_control_assert()
479 	if (rstc->shared) {  in reset_control_assert()
480 		if (WARN_ON(atomic_read(&rstc->triggered_count) != 0))  in reset_control_assert()
481 			return -EINVAL;  in reset_control_assert()
483 		if (WARN_ON(atomic_read(&rstc->deassert_count) == 0))  in reset_control_assert()
484 			return -EINVAL;  in reset_control_assert()
486 		if (atomic_dec_return(&rstc->deassert_count) != 0)  in reset_control_assert()
493 		if (!rstc->rcdev->ops->assert)  in reset_control_assert()
501 		if (!rstc->rcdev->ops->assert)  in reset_control_assert()
502 			return -ENOTSUPP;  in reset_control_assert()
504 		if (!rstc->acquired) {  in reset_control_assert()
506 			     rcdev_name(rstc->rcdev), rstc->id);  in reset_control_assert()
507 			return -EPERM;  in reset_control_assert()
511 	return rstc->rcdev->ops->assert(rstc->rcdev, rstc->id);  in reset_control_assert()
516  * reset_control_bulk_assert - asserts the reset lines in order
539 	while (i--)  in reset_control_bulk_assert()
546  * reset_control_deassert - deasserts the reset line
551  * reset_control_(de)assert has been used.
562 		return -EINVAL;  in reset_control_deassert()
567 	if (rstc->shared) {  in reset_control_deassert()
568 		if (WARN_ON(atomic_read(&rstc->triggered_count) != 0))  in reset_control_deassert()
569 			return -EINVAL;  in reset_control_deassert()
571 		if (atomic_inc_return(&rstc->deassert_count) != 1)  in reset_control_deassert()
574 		if (!rstc->acquired) {  in reset_control_deassert()
576 			     rcdev_name(rstc->rcdev), rstc->id);  in reset_control_deassert()
577 			return -EPERM;  in reset_control_deassert()
583 	 * that it handles self-deasserting reset lines via .reset(). In that  in reset_control_deassert()
586 	 * return -ENOTSUPP.  in reset_control_deassert()
588 	if (!rstc->rcdev->ops->deassert)  in reset_control_deassert()
591 	return rstc->rcdev->ops->deassert(rstc->rcdev, rstc->id);  in reset_control_deassert()
596  * reset_control_bulk_deassert - deasserts the reset lines in reverse order
610 	for (i = num_rstcs - 1; i >= 0; i--) {  in reset_control_bulk_deassert()
626  * reset_control_status - returns a negative errno if not supported, a
637 		return -EINVAL;  in reset_control_status()
639 	if (rstc->rcdev->ops->status)  in reset_control_status()
640 		return rstc->rcdev->ops->status(rstc->rcdev, rstc->id);  in reset_control_status()
642 	return -ENOTSUPP;  in reset_control_status()
647  * reset_control_acquire() - acquires a reset control for exclusive use
674 		return -EINVAL;  in reset_control_acquire()
681 	if (rstc->acquired) {  in reset_control_acquire()
686 	list_for_each_entry(rc, &rstc->rcdev->reset_control_head, list) {  in reset_control_acquire()
687 		if (rstc != rc && rstc->id == rc->id) {  in reset_control_acquire()
688 			if (rc->acquired) {  in reset_control_acquire()
690 				return -EBUSY;  in reset_control_acquire()
695 	rstc->acquired = true;  in reset_control_acquire()
703  * reset_control_bulk_acquire - acquires reset controls for exclusive use
726 	while (i--)  in reset_control_bulk_acquire()
733  * reset_control_release() - releases exclusive access to a reset control
750 		rstc->acquired = false;  in reset_control_release()
755  * reset_control_bulk_release() - releases exclusive access to reset controls
787 		return ERR_PTR(-EINVAL);  in __reset_control_get_internal()
789 	list_for_each_entry(rstc, &rcdev->reset_control_head, list) {  in __reset_control_get_internal()
790 		if (rstc->id == index) {  in __reset_control_get_internal()
796 			if (!rstc->shared && !shared && !acquired)  in __reset_control_get_internal()
799 			if (WARN_ON(!rstc->shared || !shared))  in __reset_control_get_internal()
800 				return ERR_PTR(-EBUSY);  in __reset_control_get_internal()
802 			kref_get(&rstc->refcnt);  in __reset_control_get_internal()
809 		return ERR_PTR(-ENOMEM);  in __reset_control_get_internal()
811 	if (!try_module_get(rcdev->owner)) {  in __reset_control_get_internal()
813 		return ERR_PTR(-ENODEV);  in __reset_control_get_internal()
816 	rstc->rcdev = rcdev;  in __reset_control_get_internal()
817 	list_add(&rstc->list, &rcdev->reset_control_head);  in __reset_control_get_internal()
818 	rstc->id = index;  in __reset_control_get_internal()
819 	kref_init(&rstc->refcnt);  in __reset_control_get_internal()
820 	rstc->acquired = acquired;  in __reset_control_get_internal()
821 	rstc->shared = shared;  in __reset_control_get_internal()
822 	get_device(rcdev->dev);  in __reset_control_get_internal()
834 	module_put(rstc->rcdev->owner);  in __reset_control_release()
836 	list_del(&rstc->list);  in __reset_control_release()
837 	put_device(rstc->rcdev->dev);  in __reset_control_release()
848 	kref_put(&rstc->refcnt, __reset_control_release);  in __reset_control_put_internal()
861 	 * constants from include/dt-bindings/gpio/gpio.h and  in __reset_add_reset_gpio_lookup()
865 		pr_err("reset-gpio code does not support GPIO flags %u for GPIO %u\n",  in __reset_add_reset_gpio_lookup()
867 		return -EINVAL;  in __reset_add_reset_gpio_lookup()
872 		return -EPROBE_DEFER;  in __reset_add_reset_gpio_lookup()
876 		return -EINVAL;  in __reset_add_reset_gpio_lookup()
880 		return -ENOMEM;  in __reset_add_reset_gpio_lookup()
886 		return -ENOMEM;  in __reset_add_reset_gpio_lookup()
888 	lookup->dev_id = kasprintf(GFP_KERNEL, "reset-gpio.%d", id);  in __reset_add_reset_gpio_lookup()
889 	if (!lookup->dev_id)  in __reset_add_reset_gpio_lookup()
890 		return -ENOMEM;  in __reset_add_reset_gpio_lookup()
894 	lookup->table[0] = GPIO_LOOKUP(no_free_ptr(label), gpio, "reset",  in __reset_add_reset_gpio_lookup()
913 	 * Currently only #gpio-cells=2 is supported with the meaning of:  in __reset_add_reset_gpio_device()
918 	if (args->args_count != 2)  in __reset_add_reset_gpio_device()
919 		return -ENOENT;  in __reset_add_reset_gpio_device()
922 	 * Registering reset-gpio device might cause immediate  in __reset_add_reset_gpio_device()
931 		if (args->np == rgpio_dev->of_args.np) {  in __reset_add_reset_gpio_device()
932 			if (of_phandle_args_equal(args, &rgpio_dev->of_args))  in __reset_add_reset_gpio_device()
944 		ret = -ENOMEM;  in __reset_add_reset_gpio_device()
948 	ret = __reset_add_reset_gpio_lookup(id, args->np, args->args[0],  in __reset_add_reset_gpio_device()
949 					    args->args[1]);  in __reset_add_reset_gpio_device()
953 	rgpio_dev->of_args = *args;  in __reset_add_reset_gpio_device()
959 	of_node_get(rgpio_dev->of_args.np);  in __reset_add_reset_gpio_device()
960 	pdev = platform_device_register_data(NULL, "reset-gpio", id,  in __reset_add_reset_gpio_device()
961 					     &rgpio_dev->of_args,  in __reset_add_reset_gpio_device()
962 					     sizeof(rgpio_dev->of_args));  in __reset_add_reset_gpio_device()
967 	list_add(&rgpio_dev->list, &reset_gpio_lookup_list);  in __reset_add_reset_gpio_device()
972 	of_node_put(rgpio_dev->of_args.np);  in __reset_add_reset_gpio_device()
990 			if (rcdev->of_args && of_phandle_args_equal(args,  in __reset_find_rcdev()
991 								    rcdev->of_args))  in __reset_find_rcdev()
994 			if (args->np == rcdev->of_node)  in __reset_find_rcdev()
1015 		return ERR_PTR(-EINVAL);  in __of_reset_control_get()
1019 						 "reset-names", id);  in __of_reset_control_get()
1020 		if (index == -EILSEQ)  in __of_reset_control_get()
1023 			return optional ? NULL : ERR_PTR(-ENOENT);  in __of_reset_control_get()
1026 	ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",  in __of_reset_control_get()
1028 	if (ret == -EINVAL)  in __of_reset_control_get()
1035 		 * There can be only one reset-gpio for regular devices, so  in __of_reset_control_get()
1036 		 * don't bother with the "reset-gpios" phandle index.  in __of_reset_control_get()
1038 		ret = of_parse_phandle_with_args(node, "reset-gpios", "#gpio-cells",  in __of_reset_control_get()
1055 		rstc = ERR_PTR(-EPROBE_DEFER);  in __of_reset_control_get()
1059 	if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) {  in __of_reset_control_get()
1060 		rstc = ERR_PTR(-EINVAL);  in __of_reset_control_get()
1064 	rstc_id = rcdev->of_xlate(rcdev, &args);  in __of_reset_control_get()
1092 		if (!rcdev->dev)  in __reset_controller_by_name()
1095 		if (!strcmp(name, dev_name(rcdev->dev)))  in __reset_controller_by_name()
1115 		if (strcmp(lookup->dev_id, dev_id))  in __reset_control_get_from_lookup()
1118 		if ((!con_id && !lookup->con_id) ||  in __reset_control_get_from_lookup()
1119 		    ((con_id && lookup->con_id) &&  in __reset_control_get_from_lookup()
1120 		     !strcmp(con_id, lookup->con_id))) {  in __reset_control_get_from_lookup()
1122 			rcdev = __reset_controller_by_name(lookup->provider);  in __reset_control_get_from_lookup()
1127 				return ERR_PTR(-EPROBE_DEFER);  in __reset_control_get_from_lookup()
1133 							    lookup->index,  in __reset_control_get_from_lookup()
1143 		return optional ? NULL : ERR_PTR(-ENOENT);  in __reset_control_get_from_lookup()
1155 		return ERR_PTR(-EINVAL);  in __reset_control_get()
1157 	if (dev->of_node)  in __reset_control_get()
1158 		return __of_reset_control_get(dev->of_node, id, index, flags);  in __reset_control_get()
1182 	while (i--)  in __reset_control_bulk_get()
1194 	for (i = 0; i < resets->num_rstcs; i++)  in reset_control_array_put()
1195 		__reset_control_put_internal(resets->rstc[i]);  in reset_control_array_put()
1201  * reset_control_put - free the reset controller
1221  * reset_control_bulk_put - free the reset controllers
1228 	while (num_rstcs--)  in reset_control_bulk_put()
1258 		return ERR_PTR(-ENOMEM);  in __devm_reset_control_get()
1295 	reset_control_bulk_put(devres->num_rstcs, devres->rstcs);  in devm_reset_control_bulk_release()
1302 	reset_control_bulk_assert(devres->num_rstcs, devres->rstcs);  in devm_reset_control_bulk_release_deasserted()
1303 	reset_control_bulk_put(devres->num_rstcs, devres->rstcs);  in devm_reset_control_bulk_release_deasserted()
1318 		return -ENOMEM;  in __devm_reset_control_bulk_get()
1337 	ptr->num_rstcs = num_rstcs;  in __devm_reset_control_bulk_get()
1338 	ptr->rstcs = rstcs;  in __devm_reset_control_bulk_get()
1346  * __device_reset - find reset controller associated with the device
1366 			return optional ? 0 : -ENOENT;  in __device_reset()
1369 			return -EIO;  in __device_reset()
1391  * of_reset_control_get_count - Count number of resets available with a device
1403 		return -EINVAL;  in of_reset_control_get_count()
1405 	count = of_count_phandle_with_args(node, "resets", "#reset-cells");  in of_reset_control_get_count()
1407 		count = -ENOENT;  in of_reset_control_get_count()
1413  * of_reset_control_array_get - Get a list of reset controls using
1435 		return ERR_PTR(-ENOMEM);  in of_reset_control_array_get()
1436 	resets->num_rstcs = num;  in of_reset_control_array_get()
1442 		resets->rstc[i] = rstc;  in of_reset_control_array_get()
1444 	resets->base.array = true;  in of_reset_control_array_get()
1446 	return &resets->base;  in of_reset_control_array_get()
1450 	while (--i >= 0)  in of_reset_control_array_get()
1451 		__reset_control_put_internal(resets->rstc[i]);  in of_reset_control_array_get()
1461  * devm_reset_control_array_get - Resource managed reset control array get
1480 		return ERR_PTR(-ENOMEM);  in devm_reset_control_array_get()
1482 	rstc = of_reset_control_array_get(dev->of_node, flags);  in devm_reset_control_array_get()
1502 		return -EINVAL;  in reset_control_get_count_from_lookup()
1508 		if (!strcmp(lookup->dev_id, dev_id))  in reset_control_get_count_from_lookup()
1515 		count = -ENOENT;  in reset_control_get_count_from_lookup()
1521  * reset_control_get_count - Count number of resets available with a device
1530 	if (dev->of_node)  in reset_control_get_count()
1531 		return of_reset_control_get_count(dev->of_node);  in reset_control_get_count()