1 // SPDX-License-Identifier: GPL-2.0-or-later
24 #include <linux/reset-controller.h>
36  * struct reset_control - a reset control
64  * struct reset_control_array - an array of reset controls
76  * struct reset_gpio_lookup - lookup key for ad-hoc created reset-gpio devices
89 	if (rcdev->dev)  in rcdev_name()
90 		return dev_name(rcdev->dev);  in rcdev_name()
92 	if (rcdev->of_node)  in rcdev_name()
93 		return rcdev->of_node->full_name;  in rcdev_name()
95 	if (rcdev->of_args)  in rcdev_name()
96 		return rcdev->of_args->np->full_name;  in rcdev_name()
102  * of_reset_simple_xlate - translate reset_spec to the reset line number
114 	if (reset_spec->args[0] >= rcdev->nr_resets)  in of_reset_simple_xlate()
115 		return -EINVAL;  in of_reset_simple_xlate()
117 	return reset_spec->args[0];  in of_reset_simple_xlate()
121  * reset_controller_register - register a reset controller device
126 	if (rcdev->of_node && rcdev->of_args)  in reset_controller_register()
127 		return -EINVAL;  in reset_controller_register()
129 	if (!rcdev->of_xlate) {  in reset_controller_register()
130 		rcdev->of_reset_n_cells = 1;  in reset_controller_register()
131 		rcdev->of_xlate = of_reset_simple_xlate;  in reset_controller_register()
134 	INIT_LIST_HEAD(&rcdev->reset_control_head);  in reset_controller_register()
137 	list_add(&rcdev->list, &reset_controller_list);  in reset_controller_register()
145  * reset_controller_unregister - unregister a reset controller device
151 	list_del(&rcdev->list);  in reset_controller_unregister()
162  * devm_reset_controller_register - resource managed reset_controller_register()
179 		return -ENOMEM;  in devm_reset_controller_register()
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()
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()
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()
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()
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()
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.
321  * Consumers must not use reset_control_(de)assert on shared reset lines when
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"
396  * Consumers must not use reset_control_(de)assert on shared reset lines when
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
437  * reset_control_(de)assert has been used.
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
525  * reset_control_(de)assert has been used.
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
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
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
761 		return ERR_PTR(-EINVAL);  in __reset_control_get_internal()
763 	list_for_each_entry(rstc, &rcdev->reset_control_head, list) {  in __reset_control_get_internal()
764 		if (rstc->id == index) {  in __reset_control_get_internal()
770 			if (!rstc->shared && !shared && !acquired)  in __reset_control_get_internal()
773 			if (WARN_ON(!rstc->shared || !shared))  in __reset_control_get_internal()
774 				return ERR_PTR(-EBUSY);  in __reset_control_get_internal()
776 			kref_get(&rstc->refcnt);  in __reset_control_get_internal()
783 		return ERR_PTR(-ENOMEM);  in __reset_control_get_internal()
785 	if (!try_module_get(rcdev->owner)) {  in __reset_control_get_internal()
787 		return ERR_PTR(-ENODEV);  in __reset_control_get_internal()
790 	rstc->rcdev = rcdev;  in __reset_control_get_internal()
791 	list_add(&rstc->list, &rcdev->reset_control_head);  in __reset_control_get_internal()
792 	rstc->id = index;  in __reset_control_get_internal()
793 	kref_init(&rstc->refcnt);  in __reset_control_get_internal()
794 	rstc->acquired = acquired;  in __reset_control_get_internal()
795 	rstc->shared = shared;  in __reset_control_get_internal()
796 	get_device(rcdev->dev);  in __reset_control_get_internal()
808 	module_put(rstc->rcdev->owner);  in __reset_control_release()
810 	list_del(&rstc->list);  in __reset_control_release()
811 	put_device(rstc->rcdev->dev);  in __reset_control_release()
822 	kref_put(&rstc->refcnt, __reset_control_release);  in __reset_control_put_internal()
841 		return -ENOMEM;  in reset_add_gpio_aux_device()
843 	adev->id = id;  in reset_add_gpio_aux_device()
844 	adev->name = "gpio";  in reset_add_gpio_aux_device()
845 	adev->dev.parent = parent;  in reset_add_gpio_aux_device()
846 	adev->dev.platform_data = pdata;  in reset_add_gpio_aux_device()
847 	adev->dev.release = reset_gpio_aux_device_release;  in reset_add_gpio_aux_device()
848 	device_set_node(&adev->dev, swnode);  in reset_add_gpio_aux_device()
878 	 * Currently only #gpio-cells=2 is supported with the meaning of:  in __reset_add_reset_gpio_device()
883 	if (args->args_count != 2)  in __reset_add_reset_gpio_device()
884 		return -ENOENT;  in __reset_add_reset_gpio_device()
887 	 * Registering reset-gpio device might cause immediate  in __reset_add_reset_gpio_device()
893 	offset = args->args[0];  in __reset_add_reset_gpio_device()
894 	of_flags = args->args[1];  in __reset_add_reset_gpio_device()
898 	 * constants from include/dt-bindings/gpio/gpio.h and  in __reset_add_reset_gpio_device()
905 		pr_err("reset-gpio code does not support GPIO flags %u for GPIO %u\n",  in __reset_add_reset_gpio_device()
907 		return -EINVAL;  in __reset_add_reset_gpio_device()
911 		gpio_device_find_by_fwnode(of_fwnode_handle(args->np));  in __reset_add_reset_gpio_device()
913 		return -EPROBE_DEFER;  in __reset_add_reset_gpio_device()
918 		if (args->np == rgpio_dev->of_args.np) {  in __reset_add_reset_gpio_device()
919 			if (of_phandle_args_equal(args, &rgpio_dev->of_args))  in __reset_add_reset_gpio_device()
926 	properties[0] = PROPERTY_ENTRY_GPIO("reset-gpios", parent->fwnode, offset, lflags);  in __reset_add_reset_gpio_device()
935 		ret = -ENOMEM;  in __reset_add_reset_gpio_device()
939 	rgpio_dev->of_args = *args;  in __reset_add_reset_gpio_device()
945 	of_node_get(rgpio_dev->of_args.np);  in __reset_add_reset_gpio_device()
947 	rgpio_dev->swnode = fwnode_create_software_node(properties, NULL);  in __reset_add_reset_gpio_device()
948 	if (IS_ERR(rgpio_dev->swnode)) {  in __reset_add_reset_gpio_device()
949 		ret = PTR_ERR(rgpio_dev->swnode);  in __reset_add_reset_gpio_device()
953 	ret = reset_add_gpio_aux_device(parent, rgpio_dev->swnode, id,  in __reset_add_reset_gpio_device()
954 					&rgpio_dev->of_args);  in __reset_add_reset_gpio_device()
958 	list_add(&rgpio_dev->list, &reset_gpio_lookup_list);  in __reset_add_reset_gpio_device()
963 	fwnode_remove_software_node(rgpio_dev->swnode);  in __reset_add_reset_gpio_device()
965 	of_node_put(rgpio_dev->of_args.np);  in __reset_add_reset_gpio_device()
982 			if (rcdev->of_args && of_phandle_args_equal(args,  in __reset_find_rcdev()
983 								    rcdev->of_args))  in __reset_find_rcdev()
986 			if (args->np == rcdev->of_node)  in __reset_find_rcdev()
1007 		return ERR_PTR(-EINVAL);  in __of_reset_control_get()
1011 						 "reset-names", id);  in __of_reset_control_get()
1012 		if (index == -EILSEQ)  in __of_reset_control_get()
1015 			return optional ? NULL : ERR_PTR(-ENOENT);  in __of_reset_control_get()
1018 	ret = of_parse_phandle_with_args(node, "resets", "#reset-cells",  in __of_reset_control_get()
1020 	if (ret == -EINVAL)  in __of_reset_control_get()
1027 		 * There can be only one reset-gpio for regular devices, so  in __of_reset_control_get()
1028 		 * don't bother with the "reset-gpios" phandle index.  in __of_reset_control_get()
1030 		ret = of_parse_phandle_with_args(node, "reset-gpios", "#gpio-cells",  in __of_reset_control_get()
1047 		rstc = ERR_PTR(-EPROBE_DEFER);  in __of_reset_control_get()
1051 	if (WARN_ON(args.args_count != rcdev->of_reset_n_cells)) {  in __of_reset_control_get()
1052 		rstc = ERR_PTR(-EINVAL);  in __of_reset_control_get()
1056 	rstc_id = rcdev->of_xlate(rcdev, &args);  in __of_reset_control_get()
1084 		return ERR_PTR(-EINVAL);  in __reset_control_get()
1086 	if (dev->of_node)  in __reset_control_get()
1087 		return __of_reset_control_get(dev->of_node, id, index, flags);  in __reset_control_get()
1089 	return optional ? NULL : ERR_PTR(-ENOENT);  in __reset_control_get()
1111 	while (i--)  in __reset_control_bulk_get()
1123 	for (i = 0; i < resets->num_rstcs; i++)  in reset_control_array_put()
1124 		__reset_control_put_internal(resets->rstc[i]);  in reset_control_array_put()
1130  * reset_control_put - free the reset controller
1150  * reset_control_bulk_put - free the reset controllers
1157 	while (num_rstcs--)  in reset_control_bulk_put()
1187 		return ERR_PTR(-ENOMEM);  in __devm_reset_control_get()
1224 	reset_control_bulk_put(devres->num_rstcs, devres->rstcs);  in devm_reset_control_bulk_release()
1231 	reset_control_bulk_assert(devres->num_rstcs, devres->rstcs);  in devm_reset_control_bulk_release_deasserted()
1232 	reset_control_bulk_put(devres->num_rstcs, devres->rstcs);  in devm_reset_control_bulk_release_deasserted()
1247 		return -ENOMEM;  in __devm_reset_control_bulk_get()
1266 	ptr->num_rstcs = num_rstcs;  in __devm_reset_control_bulk_get()
1267 	ptr->rstcs = rstcs;  in __devm_reset_control_bulk_get()
1275  * __device_reset - find reset controller associated with the device
1295 			return optional ? 0 : -ENOENT;  in __device_reset()
1298 			return -EIO;  in __device_reset()
1320  * of_reset_control_get_count - Count number of resets available with a device
1332 		return -EINVAL;  in of_reset_control_get_count()
1334 	count = of_count_phandle_with_args(node, "resets", "#reset-cells");  in of_reset_control_get_count()
1336 		count = -ENOENT;  in of_reset_control_get_count()
1342  * of_reset_control_array_get - Get a list of reset controls using
1364 		return ERR_PTR(-ENOMEM);  in of_reset_control_array_get()
1365 	resets->num_rstcs = num;  in of_reset_control_array_get()
1371 		resets->rstc[i] = rstc;  in of_reset_control_array_get()
1373 	resets->base.array = true;  in of_reset_control_array_get()
1375 	return &resets->base;  in of_reset_control_array_get()
1379 	while (--i >= 0)  in of_reset_control_array_get()
1380 		__reset_control_put_internal(resets->rstc[i]);  in of_reset_control_array_get()
1390  * devm_reset_control_array_get - Resource managed reset control array get
1409 		return ERR_PTR(-ENOMEM);  in devm_reset_control_array_get()
1411 	rstc = of_reset_control_array_get(dev->of_node, flags);  in devm_reset_control_array_get()
1425  * reset_control_get_count - Count number of resets available with a device
1434 	if (dev->of_node)  in reset_control_get_count()
1435 		return of_reset_control_get_count(dev->of_node);  in reset_control_get_count()
1437 	return -ENOENT;  in reset_control_get_count()