1 files changed, 275 insertions, 98 deletions

diff --git a/drivers/leds/led-triggers.c b/drivers/leds/led-triggers.c
index 3c972b2f9893..3799dcc1cf07 100644
--- a/drivers/leds/led-triggers.c
+++ b/drivers/leds/led-triggers.c
@@ -1,19 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * LED Triggers Core
  *
  * Copyright 2005-2007 Openedhand Ltd.
  *
  * Author: Richard Purdie <rpurdie@openedhand.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
  */
 
-#include <linux/module.h>
+#include <linux/export.h>
 #include <linux/kernel.h>
-#include <linux/init.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/device.h>
@@ -21,6 +16,7 @@
 #include <linux/rwsem.h>
 #include <linux/leds.h>
 #include <linux/slab.h>
+#include <linux/mm.h>
 #include "leds.h"
 
 /*
@@ -31,112 +27,236 @@ static LIST_HEAD(trigger_list);
 
  /* Used by LED Class */
 
-ssize_t led_trigger_store(struct device *dev, struct device_attribute *attr,
-		const char *buf, size_t count)
+static inline bool
+trigger_relevant(struct led_classdev *led_cdev, struct led_trigger *trig)
 {
+	return !trig->trigger_type || trig->trigger_type == led_cdev->trigger_type;
+}
+
+ssize_t led_trigger_write(struct file *filp, struct kobject *kobj,
+			  const struct bin_attribute *bin_attr, char *buf,
+			  loff_t pos, size_t count)
+{
+	struct device *dev = kobj_to_dev(kobj);
 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
-	char trigger_name[TRIG_NAME_MAX];
 	struct led_trigger *trig;
-	size_t len;
+	int ret = count;
 
-	trigger_name[sizeof(trigger_name) - 1] = '\0';
-	strncpy(trigger_name, buf, sizeof(trigger_name) - 1);
-	len = strlen(trigger_name);
+	mutex_lock(&led_cdev->led_access);
 
-	if (len && trigger_name[len - 1] == '\n')
-		trigger_name[len - 1] = '\0';
+	if (led_sysfs_is_disabled(led_cdev)) {
+		ret = -EBUSY;
+		goto unlock;
+	}
 
-	if (!strcmp(trigger_name, "none")) {
+	if (sysfs_streq(buf, "none")) {
 		led_trigger_remove(led_cdev);
-		return count;
+		goto unlock;
+	}
+
+	if (sysfs_streq(buf, "default")) {
+		led_trigger_set_default(led_cdev);
+		goto unlock;
 	}
 
 	down_read(&triggers_list_lock);
 	list_for_each_entry(trig, &trigger_list, next_trig) {
-		if (!strcmp(trigger_name, trig->name)) {
+		if (sysfs_streq(buf, trig->name) && trigger_relevant(led_cdev, trig)) {
 			down_write(&led_cdev->trigger_lock);
 			led_trigger_set(led_cdev, trig);
 			up_write(&led_cdev->trigger_lock);
 
 			up_read(&triggers_list_lock);
-			return count;
+			goto unlock;
 		}
 	}
+	/* we come here only if buf matches no trigger */
+	ret = -EINVAL;
 	up_read(&triggers_list_lock);
 
-	return -EINVAL;
+unlock:
+	mutex_unlock(&led_cdev->led_access);
+	return ret;
 }
-EXPORT_SYMBOL_GPL(led_trigger_store);
+EXPORT_SYMBOL_GPL(led_trigger_write);
 
-ssize_t led_trigger_show(struct device *dev, struct device_attribute *attr,
-		char *buf)
+__printf(3, 4)
+static int led_trigger_snprintf(char *buf, ssize_t size, const char *fmt, ...)
+{
+	va_list args;
+	int i;
+
+	va_start(args, fmt);
+	if (size <= 0)
+		i = vsnprintf(NULL, 0, fmt, args);
+	else
+		i = vscnprintf(buf, size, fmt, args);
+	va_end(args);
+
+	return i;
+}
+
+static int led_trigger_format(char *buf, size_t size,
+			      struct led_classdev *led_cdev)
 {
-	struct led_classdev *led_cdev = dev_get_drvdata(dev);
 	struct led_trigger *trig;
-	int len = 0;
+	int len = led_trigger_snprintf(buf, size, "%s",
+				       led_cdev->trigger ? "none" : "[none]");
+
+	if (led_cdev->default_trigger)
+		len += led_trigger_snprintf(buf + len, size - len, " default");
+
+	list_for_each_entry(trig, &trigger_list, next_trig) {
+		bool hit;
+
+		if (!trigger_relevant(led_cdev, trig))
+			continue;
+
+		hit = led_cdev->trigger && !strcmp(led_cdev->trigger->name, trig->name);
+
+		len += led_trigger_snprintf(buf + len, size - len,
+					    " %s%s%s", hit ? "[" : "",
+					    trig->name, hit ? "]" : "");
+	}
+
+	len += led_trigger_snprintf(buf + len, size - len, "\n");
+
+	return len;
+}
+
+/*
+ * It was stupid to create 10000 cpu triggers, but we are stuck with it now.
+ * Don't make that mistake again. We work around it here by creating binary
+ * attribute, which is not limited by length. This is _not_ good design, do not
+ * copy it.
+ */
+ssize_t led_trigger_read(struct file *filp, struct kobject *kobj,
+			const struct bin_attribute *attr, char *buf,
+			loff_t pos, size_t count)
+{
+	struct device *dev = kobj_to_dev(kobj);
+	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	void *data;
+	int len;
 
 	down_read(&triggers_list_lock);
 	down_read(&led_cdev->trigger_lock);
 
-	if (!led_cdev->trigger)
-		len += sprintf(buf+len, "[none] ");
-	else
-		len += sprintf(buf+len, "none ");
-
-	list_for_each_entry(trig, &trigger_list, next_trig) {
-		if (led_cdev->trigger && !strcmp(led_cdev->trigger->name,
-							trig->name))
-			len += sprintf(buf+len, "[%s] ", trig->name);
-		else
-			len += sprintf(buf+len, "%s ", trig->name);
+	len = led_trigger_format(NULL, 0, led_cdev);
+	data = kvmalloc(len + 1, GFP_KERNEL);
+	if (!data) {
+		up_read(&led_cdev->trigger_lock);
+		up_read(&triggers_list_lock);
+		return -ENOMEM;
 	}
+	len = led_trigger_format(data, len + 1, led_cdev);
+
 	up_read(&led_cdev->trigger_lock);
 	up_read(&triggers_list_lock);
 
-	len += sprintf(len+buf, "\n");
+	len = memory_read_from_buffer(buf, count, &pos, data, len);
+
+	kvfree(data);
+
 	return len;
 }
-EXPORT_SYMBOL_GPL(led_trigger_show);
+EXPORT_SYMBOL_GPL(led_trigger_read);
 
 /* Caller must ensure led_cdev->trigger_lock held */
-void led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
+int led_trigger_set(struct led_classdev *led_cdev, struct led_trigger *trig)
 {
-	unsigned long flags;
 	char *event = NULL;
 	char *envp[2];
 	const char *name;
+	int ret;
+
+	if (!led_cdev->trigger && !trig)
+		return 0;
 
 	name = trig ? trig->name : "none";
 	event = kasprintf(GFP_KERNEL, "TRIGGER=%s", name);
 
 	/* Remove any existing trigger */
 	if (led_cdev->trigger) {
-		write_lock_irqsave(&led_cdev->trigger->leddev_list_lock, flags);
-		list_del(&led_cdev->trig_list);
-		write_unlock_irqrestore(&led_cdev->trigger->leddev_list_lock,
-			flags);
+		spin_lock(&led_cdev->trigger->leddev_list_lock);
+		list_del_rcu(&led_cdev->trig_list);
+		spin_unlock(&led_cdev->trigger->leddev_list_lock);
+
+		/* ensure it's no longer visible on the led_cdevs list */
+		synchronize_rcu();
+
 		cancel_work_sync(&led_cdev->set_brightness_work);
 		led_stop_software_blink(led_cdev);
+		device_remove_groups(led_cdev->dev, led_cdev->trigger->groups);
 		if (led_cdev->trigger->deactivate)
 			led_cdev->trigger->deactivate(led_cdev);
 		led_cdev->trigger = NULL;
+		led_cdev->trigger_data = NULL;
+		led_cdev->activated = false;
+		led_cdev->flags &= ~LED_INIT_DEFAULT_TRIGGER;
 		led_set_brightness(led_cdev, LED_OFF);
 	}
 	if (trig) {
-		write_lock_irqsave(&trig->leddev_list_lock, flags);
-		list_add_tail(&led_cdev->trig_list, &trig->led_cdevs);
-		write_unlock_irqrestore(&trig->leddev_list_lock, flags);
+		spin_lock(&trig->leddev_list_lock);
+		list_add_tail_rcu(&led_cdev->trig_list, &trig->led_cdevs);
+		spin_unlock(&trig->leddev_list_lock);
 		led_cdev->trigger = trig;
+
+		/*
+		 * Some activate() calls use led_trigger_event() to initialize
+		 * the brightness of the LED for which the trigger is being set.
+		 * Ensure the led_cdev is visible on trig->led_cdevs for this.
+		 */
+		synchronize_rcu();
+
+		/*
+		 * If "set brightness to 0" is pending in workqueue,
+		 * we don't want that to be reordered after ->activate()
+		 */
+		flush_work(&led_cdev->set_brightness_work);
+
+		ret = 0;
 		if (trig->activate)
-			trig->activate(led_cdev);
+			ret = trig->activate(led_cdev);
+		else
+			led_set_brightness(led_cdev, trig->brightness);
+		if (ret)
+			goto err_activate;
+
+		ret = device_add_groups(led_cdev->dev, trig->groups);
+		if (ret) {
+			dev_err(led_cdev->dev, "Failed to add trigger attributes\n");
+			goto err_add_groups;
+		}
 	}
 
 	if (event) {
 		envp[0] = event;
 		envp[1] = NULL;
-		kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp);
+		if (kobject_uevent_env(&led_cdev->dev->kobj, KOBJ_CHANGE, envp))
+			dev_err(led_cdev->dev,
+				"%s: Error sending uevent\n", __func__);
 		kfree(event);
 	}
+
+	return 0;
+
+err_add_groups:
+
+	if (trig->deactivate)
+		trig->deactivate(led_cdev);
+err_activate:
+
+	spin_lock(&led_cdev->trigger->leddev_list_lock);
+	list_del_rcu(&led_cdev->trig_list);
+	spin_unlock(&led_cdev->trigger->leddev_list_lock);
+	synchronize_rcu();
+	led_cdev->trigger = NULL;
+	led_cdev->trigger_data = NULL;
+	led_set_brightness(led_cdev, LED_OFF);
+	kfree(event);
+
+	return ret;
 }
 EXPORT_SYMBOL_GPL(led_trigger_set);
 
@@ -148,36 +268,50 @@ void led_trigger_remove(struct led_classdev *led_cdev)
 }
 EXPORT_SYMBOL_GPL(led_trigger_remove);
 
+static bool led_match_default_trigger(struct led_classdev *led_cdev,
+				      struct led_trigger *trig)
+{
+	if (!strcmp(led_cdev->default_trigger, trig->name) &&
+	    trigger_relevant(led_cdev, trig)) {
+		led_cdev->flags |= LED_INIT_DEFAULT_TRIGGER;
+		led_trigger_set(led_cdev, trig);
+		return true;
+	}
+
+	return false;
+}
+
 void led_trigger_set_default(struct led_classdev *led_cdev)
 {
 	struct led_trigger *trig;
+	bool found = false;
 
 	if (!led_cdev->default_trigger)
 		return;
 
+	if (!strcmp(led_cdev->default_trigger, "none")) {
+		led_trigger_remove(led_cdev);
+		return;
+	}
+
 	down_read(&triggers_list_lock);
 	down_write(&led_cdev->trigger_lock);
 	list_for_each_entry(trig, &trigger_list, next_trig) {
-		if (!strcmp(led_cdev->default_trigger, trig->name))
-			led_trigger_set(led_cdev, trig);
+		found = led_match_default_trigger(led_cdev, trig);
+		if (found)
+			break;
 	}
 	up_write(&led_cdev->trigger_lock);
 	up_read(&triggers_list_lock);
-}
-EXPORT_SYMBOL_GPL(led_trigger_set_default);
-
-void led_trigger_rename_static(const char *name, struct led_trigger *trig)
-{
-	/* new name must be on a temporary string to prevent races */
-	BUG_ON(name == trig->name);
 
-	down_write(&triggers_list_lock);
-	/* this assumes that trig->name was originaly allocated to
-	 * non constant storage */
-	strcpy((char *)trig->name, name);
-	up_write(&triggers_list_lock);
+	/*
+	 * If default trigger wasn't found, maybe trigger module isn't loaded yet.
+	 * Once loaded it will re-probe with all led_cdev's.
+	 */
+	if (!found)
+		request_module_nowait("ledtrig:%s", led_cdev->default_trigger);
 }
-EXPORT_SYMBOL_GPL(led_trigger_rename_static);
+EXPORT_SYMBOL_GPL(led_trigger_set_default);
 
 /* LED Trigger Interface */
 
@@ -186,13 +320,15 @@ int led_trigger_register(struct led_trigger *trig)
 	struct led_classdev *led_cdev;
 	struct led_trigger *_trig;
 
-	rwlock_init(&trig->leddev_list_lock);
+	spin_lock_init(&trig->leddev_list_lock);
 	INIT_LIST_HEAD(&trig->led_cdevs);
 
 	down_write(&triggers_list_lock);
 	/* Make sure the trigger's name isn't already in use */
 	list_for_each_entry(_trig, &trigger_list, next_trig) {
-		if (!strcmp(_trig->name, trig->name)) {
+		if (!strcmp(_trig->name, trig->name) &&
+		    (trig->trigger_type == _trig->trigger_type ||
+		     !trig->trigger_type || !_trig->trigger_type)) {
 			up_write(&triggers_list_lock);
 			return -EEXIST;
 		}
@@ -205,9 +341,8 @@ int led_trigger_register(struct led_trigger *trig)
 	down_read(&leds_list_lock);
 	list_for_each_entry(led_cdev, &leds_list, node) {
 		down_write(&led_cdev->trigger_lock);
-		if (!led_cdev->trigger && led_cdev->default_trigger &&
-			    !strcmp(led_cdev->default_trigger, trig->name))
-			led_trigger_set(led_cdev, trig);
+		if (!led_cdev->trigger && led_cdev->default_trigger)
+			led_match_default_trigger(led_cdev, trig);
 		up_write(&led_cdev->trigger_lock);
 	}
 	up_read(&leds_list_lock);
@@ -220,9 +355,12 @@ void led_trigger_unregister(struct led_trigger *trig)
 {
 	struct led_classdev *led_cdev;
 
+	if (list_empty_careful(&trig->next_trig))
+		return;
+
 	/* Remove from the list of led triggers */
 	down_write(&triggers_list_lock);
-	list_del(&trig->next_trig);
+	list_del_init(&trig->next_trig);
 	up_write(&triggers_list_lock);
 
 	/* Remove anyone actively using this trigger */
@@ -237,63 +375,106 @@ void led_trigger_unregister(struct led_trigger *trig)
 }
 EXPORT_SYMBOL_GPL(led_trigger_unregister);
 
-/* Simple LED Tigger Interface */
+static void devm_led_trigger_release(struct device *dev, void *res)
+{
+	led_trigger_unregister(*(struct led_trigger **)res);
+}
+
+int devm_led_trigger_register(struct device *dev,
+			      struct led_trigger *trig)
+{
+	struct led_trigger **dr;
+	int rc;
+
+	dr = devres_alloc(devm_led_trigger_release, sizeof(*dr),
+			  GFP_KERNEL);
+	if (!dr)
+		return -ENOMEM;
+
+	*dr = trig;
+
+	rc = led_trigger_register(trig);
+	if (rc)
+		devres_free(dr);
+	else
+		devres_add(dev, dr);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(devm_led_trigger_register);
+
+/* Simple LED Trigger Interface */
 
 void led_trigger_event(struct led_trigger *trig,
 			enum led_brightness brightness)
 {
-	struct list_head *entry;
+	struct led_classdev *led_cdev;
 
 	if (!trig)
 		return;
 
-	read_lock(&trig->leddev_list_lock);
-	list_for_each(entry, &trig->led_cdevs) {
-		struct led_classdev *led_cdev;
+	trig->brightness = brightness;
 
-		led_cdev = list_entry(entry, struct led_classdev, trig_list);
+	rcu_read_lock();
+	list_for_each_entry_rcu(led_cdev, &trig->led_cdevs, trig_list)
 		led_set_brightness(led_cdev, brightness);
-	}
-	read_unlock(&trig->leddev_list_lock);
+	rcu_read_unlock();
 }
 EXPORT_SYMBOL_GPL(led_trigger_event);
 
+void led_mc_trigger_event(struct led_trigger *trig,
+			  unsigned int *intensity_value, unsigned int num_colors,
+			  enum led_brightness brightness)
+{
+	struct led_classdev *led_cdev;
+
+	if (!trig)
+		return;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(led_cdev, &trig->led_cdevs, trig_list) {
+		if (!(led_cdev->flags & LED_MULTI_COLOR))
+			continue;
+
+		led_mc_set_brightness(led_cdev, intensity_value, num_colors, brightness);
+	}
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(led_mc_trigger_event);
+
 static void led_trigger_blink_setup(struct led_trigger *trig,
-			     unsigned long *delay_on,
-			     unsigned long *delay_off,
+			     unsigned long delay_on,
+			     unsigned long delay_off,
 			     int oneshot,
 			     int invert)
 {
-	struct list_head *entry;
+	struct led_classdev *led_cdev;
 
 	if (!trig)
 		return;
 
-	read_lock(&trig->leddev_list_lock);
-	list_for_each(entry, &trig->led_cdevs) {
-		struct led_classdev *led_cdev;
-
-		led_cdev = list_entry(entry, struct led_classdev, trig_list);
+	rcu_read_lock();
+	list_for_each_entry_rcu(led_cdev, &trig->led_cdevs, trig_list) {
 		if (oneshot)
-			led_blink_set_oneshot(led_cdev, delay_on, delay_off,
+			led_blink_set_oneshot(led_cdev, &delay_on, &delay_off,
 					      invert);
 		else
-			led_blink_set(led_cdev, delay_on, delay_off);
+			led_blink_set_nosleep(led_cdev, delay_on, delay_off);
 	}
-	read_unlock(&trig->leddev_list_lock);
+	rcu_read_unlock();
 }
 
 void led_trigger_blink(struct led_trigger *trig,
-		       unsigned long *delay_on,
-		       unsigned long *delay_off)
+		       unsigned long delay_on,
+		       unsigned long delay_off)
 {
 	led_trigger_blink_setup(trig, delay_on, delay_off, 0, 0);
 }
 EXPORT_SYMBOL_GPL(led_trigger_blink);
 
 void led_trigger_blink_oneshot(struct led_trigger *trig,
-			       unsigned long *delay_on,
-			       unsigned long *delay_off,
+			       unsigned long delay_on,
+			       unsigned long delay_off,
 			       int invert)
 {
 	led_trigger_blink_setup(trig, delay_on, delay_off, 1, invert);
@@ -331,7 +512,3 @@ void led_trigger_unregister_simple(struct led_trigger *trig)
 	kfree(trig);
 }
 EXPORT_SYMBOL_GPL(led_trigger_unregister_simple);
-
-MODULE_AUTHOR("Richard Purdie");
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("LED Triggers Core");