1 // SPDX-License-Identifier: GPL-2.0-only
5  * Copyright 2005-2007 Openedhand Ltd.
23  * Nests outside led_cdev->trigger_lock
33 	return !trig->trigger_type || trig->trigger_type == led_cdev->trigger_type;  in trigger_relevant()
45 	mutex_lock(&led_cdev->led_access);  in led_trigger_write()
48 		ret = -EBUSY;  in led_trigger_write()
57 	if (sysfs_streq(buf, "default")) {  in led_trigger_write()
64 		if (sysfs_streq(buf, trig->name) && trigger_relevant(led_cdev, trig)) {  in led_trigger_write()
65 			down_write(&led_cdev->trigger_lock);  in led_trigger_write()
67 			up_write(&led_cdev->trigger_lock);  in led_trigger_write()
73 	/* we come here only if buf matches no trigger */  in led_trigger_write()
74 	ret = -EINVAL;  in led_trigger_write()
78 	mutex_unlock(&led_cdev->led_access);  in led_trigger_write()
104 				       led_cdev->trigger ? "none" : "[none]");  in led_trigger_format()
106 	if (led_cdev->default_trigger)  in led_trigger_format()
107 		len += led_trigger_snprintf(buf + len, size - len, " default");  in led_trigger_format()
115 		hit = led_cdev->trigger && !strcmp(led_cdev->trigger->name, trig->name);  in led_trigger_format()
117 		len += led_trigger_snprintf(buf + len, size - len,  in led_trigger_format()
119 					    trig->name, hit ? "]" : "");  in led_trigger_format()
122 	len += led_trigger_snprintf(buf + len, size - len, "\n");  in led_trigger_format()
143 	down_read(&led_cdev->trigger_lock);  in led_trigger_read()
148 		up_read(&led_cdev->trigger_lock);  in led_trigger_read()
150 		return -ENOMEM;  in led_trigger_read()
154 	up_read(&led_cdev->trigger_lock);  in led_trigger_read()
165 /* Caller must ensure led_cdev->trigger_lock held */
173 	if (!led_cdev->trigger && !trig)  in led_trigger_set()
176 	name = trig ? trig->name : "none";  in led_trigger_set()
177 	event = kasprintf(GFP_KERNEL, "TRIGGER=%s", name);  in led_trigger_set()
179 	/* Remove any existing trigger */  in led_trigger_set()
180 	if (led_cdev->trigger) {  in led_trigger_set()
181 		spin_lock(&led_cdev->trigger->leddev_list_lock);  in led_trigger_set()
182 		list_del_rcu(&led_cdev->trig_list);  in led_trigger_set()
183 		spin_unlock(&led_cdev->trigger->leddev_list_lock);  in led_trigger_set()
188 		cancel_work_sync(&led_cdev->set_brightness_work);  in led_trigger_set()
190 		device_remove_groups(led_cdev->dev, led_cdev->trigger->groups);  in led_trigger_set()
191 		if (led_cdev->trigger->deactivate)  in led_trigger_set()
192 			led_cdev->trigger->deactivate(led_cdev);  in led_trigger_set()
193 		led_cdev->trigger = NULL;  in led_trigger_set()
194 		led_cdev->trigger_data = NULL;  in led_trigger_set()
195 		led_cdev->activated = false;  in led_trigger_set()
196 		led_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER;  in led_trigger_set()
200 		spin_lock(&trig->leddev_list_lock);  in led_trigger_set()
201 		list_add_tail_rcu(&led_cdev->trig_list, &trig->led_cdevs);  in led_trigger_set()
202 		spin_unlock(&trig->leddev_list_lock);  in led_trigger_set()
203 		led_cdev->trigger = trig;  in led_trigger_set()
207 		 * the brightness of the LED for which the trigger is being set.  in led_trigger_set()
208 		 * Ensure the led_cdev is visible on trig->led_cdevs for this.  in led_trigger_set()
214 		 * we don't want that to be reordered after ->activate()  in led_trigger_set()
216 		flush_work(&led_cdev->set_brightness_work);  in led_trigger_set()
219 		if (trig->activate)  in led_trigger_set()
220 			ret = trig->activate(led_cdev);  in led_trigger_set()
222 			led_set_brightness(led_cdev, trig->brightness);  in led_trigger_set()
226 		ret = device_add_groups(led_cdev->dev, trig->groups);  in led_trigger_set()
228 			dev_err(led_cdev->dev, "Failed to add trigger attributes\n");  in led_trigger_set()
236 		if (kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp))  in led_trigger_set()
237 			dev_err(led_cdev->dev,  in led_trigger_set()
246 	if (trig->deactivate)  in led_trigger_set()
247 		trig->deactivate(led_cdev);  in led_trigger_set()
250 	spin_lock(&led_cdev->trigger->leddev_list_lock);  in led_trigger_set()
251 	list_del_rcu(&led_cdev->trig_list);  in led_trigger_set()
252 	spin_unlock(&led_cdev->trigger->leddev_list_lock);  in led_trigger_set()
254 	led_cdev->trigger = NULL;  in led_trigger_set()
255 	led_cdev->trigger_data = NULL;  in led_trigger_set()
265 	down_write(&led_cdev->trigger_lock);  in led_trigger_remove()
267 	up_write(&led_cdev->trigger_lock);  in led_trigger_remove()
274 	if (!strcmp(led_cdev->default_trigger, trig->name) &&  in led_match_default_trigger()
276 		led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;  in led_match_default_trigger()
289 	if (!led_cdev->default_trigger)  in led_trigger_set_default()
292 	if (!strcmp(led_cdev->default_trigger, "none")) {  in led_trigger_set_default()
298 	down_write(&led_cdev->trigger_lock);  in led_trigger_set_default()
304 	up_write(&led_cdev->trigger_lock);  in led_trigger_set_default()
308 	 * If default trigger wasn't found, maybe trigger module isn't loaded yet.  in led_trigger_set_default()
309 	 * Once loaded it will re-probe with all led_cdev's.  in led_trigger_set_default()
312 		request_module_nowait("ledtrig:%s", led_cdev->default_trigger);  in led_trigger_set_default()
316 /* LED Trigger Interface */
323 	spin_lock_init(&trig->leddev_list_lock);  in led_trigger_register()
324 	INIT_LIST_HEAD(&trig->led_cdevs);  in led_trigger_register()
327 	/* Make sure the trigger's name isn't already in use */  in led_trigger_register()
329 		if (!strcmp(_trig->name, trig->name) &&  in led_trigger_register()
330 		    (trig->trigger_type == _trig->trigger_type ||  in led_trigger_register()
331 		     !trig->trigger_type || !_trig->trigger_type)) {  in led_trigger_register()
333 			return -EEXIST;  in led_trigger_register()
337 	list_add_tail(&trig->next_trig, &trigger_list);  in led_trigger_register()
340 	/* Register with any LEDs that have this as a default trigger */  in led_trigger_register()
343 		down_write(&led_cdev->trigger_lock);  in led_trigger_register()
344 		if (!led_cdev->trigger && led_cdev->default_trigger)  in led_trigger_register()
346 		up_write(&led_cdev->trigger_lock);  in led_trigger_register()
358 	if (list_empty_careful(&trig->next_trig))  in led_trigger_unregister()
363 	list_del_init(&trig->next_trig);  in led_trigger_unregister()
366 	/* Remove anyone actively using this trigger */  in led_trigger_unregister()
369 		down_write(&led_cdev->trigger_lock);  in led_trigger_unregister()
370 		if (led_cdev->trigger == trig)  in led_trigger_unregister()
372 		up_write(&led_cdev->trigger_lock);  in led_trigger_unregister()
392 		return -ENOMEM;  in devm_led_trigger_register()
406 /* Simple LED Trigger Interface */
416 	trig->brightness = brightness;  in led_trigger_event()
419 	list_for_each_entry_rcu(led_cdev, &trig->led_cdevs, trig_list)  in led_trigger_event()
435 	list_for_each_entry_rcu(led_cdev, &trig->led_cdevs, trig_list) {  in led_mc_trigger_event()
436 		if (!(led_cdev->flags & LED_MULTI_COLOR))  in led_mc_trigger_event()
457 	list_for_each_entry_rcu(led_cdev, &trig->led_cdevs, trig_list) {  in led_trigger_blink_setup()
492 		trig->name = name;  in led_trigger_register_simple()
497 			pr_warn("LED trigger %s failed to register (%d)\n",  in led_trigger_register_simple()
501 		pr_warn("LED trigger %s failed to register (no memory)\n",  in led_trigger_register_simple()