1 files changed, 338 insertions, 53 deletions

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index b0e2d55acbd6..885399ed0776 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -1,12 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * LED Class Core
  *
  * Copyright (C) 2005 John Lenz <lenz@cs.wisc.edu>
  * Copyright (C) 2005-2007 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/ctype.h>
@@ -17,23 +14,31 @@
 #include <linux/leds.h>
 #include <linux/list.h>
 #include <linux/module.h>
+#include <linux/property.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/timer.h>
 #include <uapi/linux/uleds.h>
+#include <linux/of.h>
 #include "leds.h"
 
-static struct class *leds_class;
+static DEFINE_MUTEX(leds_lookup_lock);
+static LIST_HEAD(leds_lookup_list);
+
+static struct workqueue_struct *leds_wq;
 
 static ssize_t brightness_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	unsigned int brightness;
 
-	/* no lock needed for this */
+	mutex_lock(&led_cdev->led_access);
 	led_update_brightness(led_cdev);
+	brightness = led_cdev->brightness;
+	mutex_unlock(&led_cdev->led_access);
 
-	return sprintf(buf, "%u\n", led_cdev->brightness);
+	return sysfs_emit(buf, "%u\n", brightness);
 }
 
 static ssize_t brightness_store(struct device *dev,
@@ -69,19 +74,24 @@ static ssize_t max_brightness_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct led_classdev *led_cdev = dev_get_drvdata(dev);
+	unsigned int max_brightness;
 
-	return sprintf(buf, "%u\n", led_cdev->max_brightness);
+	mutex_lock(&led_cdev->led_access);
+	max_brightness = led_cdev->max_brightness;
+	mutex_unlock(&led_cdev->led_access);
+
+	return sysfs_emit(buf, "%u\n", max_brightness);
 }
 static DEVICE_ATTR_RO(max_brightness);
 
 #ifdef CONFIG_LEDS_TRIGGERS
-static DEVICE_ATTR(trigger, 0644, led_trigger_show, led_trigger_store);
-static struct attribute *led_trigger_attrs[] = {
-	&dev_attr_trigger.attr,
+static const BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
+static const struct bin_attribute *const led_trigger_bin_attrs[] = {
+	&bin_attr_trigger,
 	NULL,
 };
 static const struct attribute_group led_trigger_group = {
-	.attrs = led_trigger_attrs,
+	.bin_attrs = led_trigger_bin_attrs,
 };
 #endif
 
@@ -112,7 +122,7 @@ static ssize_t brightness_hw_changed_show(struct device *dev,
 	if (led_cdev->brightness_hw_changed == -1)
 		return -ENODATA;
 
-	return sprintf(buf, "%u\n", led_cdev->brightness_hw_changed);
+	return sysfs_emit(buf, "%u\n", led_cdev->brightness_hw_changed);
 }
 
 static DEVICE_ATTR_RO(brightness_hw_changed);
@@ -145,8 +155,7 @@ static void led_remove_brightness_hw_changed(struct led_classdev *led_cdev)
 	device_remove_file(led_cdev->dev, &dev_attr_brightness_hw_changed);
 }
 
-void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev,
-					       enum led_brightness brightness)
+void led_classdev_notify_brightness_hw_changed(struct led_classdev *led_cdev, unsigned int brightness)
 {
 	if (WARN_ON(!led_cdev->brightness_hw_changed_kn))
 		return;
@@ -173,6 +182,7 @@ void led_classdev_suspend(struct led_classdev *led_cdev)
 {
 	led_cdev->flags |= LED_SUSPENDED;
 	led_set_brightness_nopm(led_cdev, 0);
+	flush_work(&led_cdev->set_brightness_work);
 }
 EXPORT_SYMBOL_GPL(led_classdev_suspend);
 
@@ -215,13 +225,233 @@ static int led_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
 
-static int match_name(struct device *dev, const void *data)
+static struct led_classdev *led_module_get(struct device *led_dev)
 {
-	if (!dev_name(dev))
-		return 0;
-	return !strcmp(dev_name(dev), (char *)data);
+	struct led_classdev *led_cdev;
+
+	if (!led_dev)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	led_cdev = dev_get_drvdata(led_dev);
+
+	if (!try_module_get(led_cdev->dev->parent->driver->owner)) {
+		put_device(led_cdev->dev);
+		return ERR_PTR(-ENODEV);
+	}
+
+	return led_cdev;
+}
+
+static const struct class leds_class = {
+	.name = "leds",
+	.dev_groups = led_groups,
+	.pm = &leds_class_dev_pm_ops,
+};
+
+/**
+ * of_led_get() - request a LED device via the LED framework
+ * @np: device node to get the LED device from
+ * @index: the index of the LED
+ * @name: the name of the LED used to map it to its function, if present
+ *
+ * Returns the LED device parsed from the phandle specified in the "leds"
+ * property of a device tree node or a negative error-code on failure.
+ */
+static struct led_classdev *of_led_get(struct device_node *np, int index,
+				       const char *name)
+{
+	struct device *led_dev;
+	struct device_node *led_node;
+
+	/*
+	 * For named LEDs, first look up the name in the "led-names" property.
+	 * If it cannot be found, then of_parse_phandle() will propagate the error.
+	 */
+	if (name)
+		index = of_property_match_string(np, "led-names", name);
+	led_node = of_parse_phandle(np, "leds", index);
+	if (!led_node)
+		return ERR_PTR(-ENOENT);
+
+	led_dev = class_find_device_by_of_node(&leds_class, led_node);
+	of_node_put(led_node);
+
+	return led_module_get(led_dev);
+}
+
+/**
+ * led_put() - release a LED device
+ * @led_cdev: LED device
+ */
+void led_put(struct led_classdev *led_cdev)
+{
+	module_put(led_cdev->dev->parent->driver->owner);
+	put_device(led_cdev->dev);
+}
+EXPORT_SYMBOL_GPL(led_put);
+
+static void devm_led_release(struct device *dev, void *res)
+{
+	struct led_classdev **p = res;
+
+	led_put(*p);
 }
 
+static struct led_classdev *__devm_led_get(struct device *dev, struct led_classdev *led)
+{
+	struct led_classdev **dr;
+
+	dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *), GFP_KERNEL);
+	if (!dr) {
+		led_put(led);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	*dr = led;
+	devres_add(dev, dr);
+
+	return led;
+}
+
+/**
+ * devm_of_led_get - Resource-managed request of a LED device
+ * @dev:	LED consumer
+ * @index:	index of the LED to obtain in the consumer
+ *
+ * The device node of the device is parse to find the request LED device.
+ * The LED device returned from this function is automatically released
+ * on driver detach.
+ *
+ * @return a pointer to a LED device or ERR_PTR(errno) on failure.
+ */
+struct led_classdev *__must_check devm_of_led_get(struct device *dev,
+						  int index)
+{
+	struct led_classdev *led;
+
+	if (!dev)
+		return ERR_PTR(-EINVAL);
+
+	led = of_led_get(dev->of_node, index, NULL);
+	if (IS_ERR(led))
+		return led;
+
+	return __devm_led_get(dev, led);
+}
+EXPORT_SYMBOL_GPL(devm_of_led_get);
+
+/**
+ * led_get() - request a LED device via the LED framework
+ * @dev: device for which to get the LED device
+ * @con_id: name of the LED from the device's point of view
+ *
+ * @return a pointer to a LED device or ERR_PTR(errno) on failure.
+ */
+struct led_classdev *led_get(struct device *dev, char *con_id)
+{
+	struct led_lookup_data *lookup;
+	struct led_classdev *led_cdev;
+	const char *provider = NULL;
+	struct device *led_dev;
+
+	led_cdev = of_led_get(dev->of_node, -1, con_id);
+	if (!IS_ERR(led_cdev) || PTR_ERR(led_cdev) != -ENOENT)
+		return led_cdev;
+
+	mutex_lock(&leds_lookup_lock);
+	list_for_each_entry(lookup, &leds_lookup_list, list) {
+		if (!strcmp(lookup->dev_id, dev_name(dev)) &&
+		    !strcmp(lookup->con_id, con_id)) {
+			provider = kstrdup_const(lookup->provider, GFP_KERNEL);
+			break;
+		}
+	}
+	mutex_unlock(&leds_lookup_lock);
+
+	if (!provider)
+		return ERR_PTR(-ENOENT);
+
+	led_dev = class_find_device_by_name(&leds_class, provider);
+	kfree_const(provider);
+
+	return led_module_get(led_dev);
+}
+EXPORT_SYMBOL_GPL(led_get);
+
+/**
+ * devm_led_get() - request a LED device via the LED framework
+ * @dev: device for which to get the LED device
+ * @con_id: name of the LED from the device's point of view
+ *
+ * The LED device returned from this function is automatically released
+ * on driver detach.
+ *
+ * @return a pointer to a LED device or ERR_PTR(errno) on failure.
+ */
+struct led_classdev *devm_led_get(struct device *dev, char *con_id)
+{
+	struct led_classdev *led;
+
+	led = led_get(dev, con_id);
+	if (IS_ERR(led))
+		return led;
+
+	return __devm_led_get(dev, led);
+}
+EXPORT_SYMBOL_GPL(devm_led_get);
+
+/**
+ * led_add_lookup() - Add a LED lookup table entry
+ * @led_lookup: the lookup table entry to add
+ *
+ * Add a LED lookup table entry. On systems without devicetree the lookup table
+ * is used by led_get() to find LEDs.
+ */
+void led_add_lookup(struct led_lookup_data *led_lookup)
+{
+	mutex_lock(&leds_lookup_lock);
+	list_add_tail(&led_lookup->list, &leds_lookup_list);
+	mutex_unlock(&leds_lookup_lock);
+}
+EXPORT_SYMBOL_GPL(led_add_lookup);
+
+/**
+ * led_remove_lookup() - Remove a LED lookup table entry
+ * @led_lookup: the lookup table entry to remove
+ */
+void led_remove_lookup(struct led_lookup_data *led_lookup)
+{
+	mutex_lock(&leds_lookup_lock);
+	list_del(&led_lookup->list);
+	mutex_unlock(&leds_lookup_lock);
+}
+EXPORT_SYMBOL_GPL(led_remove_lookup);
+
+/**
+ * devm_of_led_get_optional - Resource-managed request of an optional LED device
+ * @dev:	LED consumer
+ * @index:	index of the LED to obtain in the consumer
+ *
+ * The device node of the device is parsed to find the requested LED device.
+ * The LED device returned from this function is automatically released
+ * on driver detach.
+ *
+ * @return a pointer to a LED device, ERR_PTR(errno) on failure and NULL if the
+ * led was not found.
+ */
+struct led_classdev *__must_check devm_of_led_get_optional(struct device *dev,
+							int index)
+{
+	struct led_classdev *led;
+
+	led = devm_of_led_get(dev, index);
+	if (IS_ERR(led) && PTR_ERR(led) == -ENOENT)
+		return NULL;
+
+	return led;
+}
+EXPORT_SYMBOL_GPL(devm_of_led_get_optional);
+
 static int led_classdev_next_name(const char *init_name, char *name,
 				  size_t len)
 {
@@ -229,10 +459,10 @@ static int led_classdev_next_name(const char *init_name, char *name,
 	int ret = 0;
 	struct device *dev;
 
-	strlcpy(name, init_name, len);
+	strscpy(name, init_name, len);
 
 	while ((ret < len) &&
-	       (dev = class_find_device(leds_class, NULL, name, match_name))) {
+	       (dev = class_find_device_by_name(&leds_class, name))) {
 		put_device(dev);
 		ret = snprintf(name, len, "%s_%u", init_name, ++i);
 	}
@@ -244,36 +474,81 @@ static int led_classdev_next_name(const char *init_name, char *name,
 }
 
 /**
- * of_led_classdev_register - register a new object of led_classdev class.
+ * led_classdev_register_ext - register a new object of led_classdev class
+ *			       with init data.
  *
  * @parent: parent of LED device
  * @led_cdev: the led_classdev structure for this device.
- * @np: DT node describing this LED
+ * @init_data: LED class device initialization data
  */
-int of_led_classdev_register(struct device *parent, struct device_node *np,
-			    struct led_classdev *led_cdev)
+int led_classdev_register_ext(struct device *parent,
+			      struct led_classdev *led_cdev,
+			      struct led_init_data *init_data)
 {
-	char name[LED_MAX_NAME_SIZE];
+	char composed_name[LED_MAX_NAME_SIZE];
+	char final_name[LED_MAX_NAME_SIZE];
+	const char *proposed_name = composed_name;
 	int ret;
 
-	ret = led_classdev_next_name(led_cdev->name, name, sizeof(name));
+	if (init_data) {
+		if (init_data->devname_mandatory && !init_data->devicename) {
+			dev_err(parent, "Mandatory device name is missing");
+			return -EINVAL;
+		}
+		ret = led_compose_name(parent, init_data, composed_name);
+		if (ret < 0)
+			return ret;
+
+		if (init_data->fwnode) {
+			fwnode_property_read_string(init_data->fwnode,
+				"linux,default-trigger",
+				&led_cdev->default_trigger);
+
+			if (fwnode_property_present(init_data->fwnode,
+						    "retain-state-shutdown"))
+				led_cdev->flags |= LED_RETAIN_AT_SHUTDOWN;
+
+			fwnode_property_read_u32(init_data->fwnode,
+				"max-brightness",
+				&led_cdev->max_brightness);
+
+			if (fwnode_property_present(init_data->fwnode, "color"))
+				fwnode_property_read_u32(init_data->fwnode, "color",
+							 &led_cdev->color);
+		}
+	} else {
+		proposed_name = led_cdev->name;
+	}
+
+	ret = led_classdev_next_name(proposed_name, final_name, sizeof(final_name));
 	if (ret < 0)
 		return ret;
+	else if (ret && led_cdev->flags & LED_REJECT_NAME_CONFLICT)
+		return -EEXIST;
+	else if (ret)
+		dev_warn(parent, "Led %s renamed to %s due to name collision\n",
+			 proposed_name, final_name);
 
-	led_cdev->dev = device_create_with_groups(leds_class, parent, 0,
-				led_cdev, led_cdev->groups, "%s", name);
-	if (IS_ERR(led_cdev->dev))
-		return PTR_ERR(led_cdev->dev);
-	led_cdev->dev->of_node = np;
+	if (led_cdev->color >= LED_COLOR_ID_MAX)
+		dev_warn(parent, "LED %s color identifier out of range\n", final_name);
 
-	if (ret)
-		dev_warn(parent, "Led %s renamed to %s due to name collision",
-				led_cdev->name, dev_name(led_cdev->dev));
+	mutex_init(&led_cdev->led_access);
+	mutex_lock(&led_cdev->led_access);
+	led_cdev->dev = device_create_with_groups(&leds_class, parent, 0,
+						  led_cdev, led_cdev->groups, "%s", final_name);
+	if (IS_ERR(led_cdev->dev)) {
+		mutex_unlock(&led_cdev->led_access);
+		return PTR_ERR(led_cdev->dev);
+	}
+	if (init_data && init_data->fwnode)
+		device_set_node(led_cdev->dev, init_data->fwnode);
 
 	if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
 		ret = led_add_brightness_hw_changed(led_cdev);
 		if (ret) {
 			device_unregister(led_cdev->dev);
+			led_cdev->dev = NULL;
+			mutex_unlock(&led_cdev->led_access);
 			return ret;
 		}
 	}
@@ -285,7 +560,6 @@ int of_led_classdev_register(struct device *parent, struct device_node *np,
 #ifdef CONFIG_LEDS_BRIGHTNESS_HW_CHANGED
 	led_cdev->brightness_hw_changed = -1;
 #endif
-	mutex_init(&led_cdev->led_access);
 	/* add to the list of leds */
 	down_write(&leds_list_lock);
 	list_add_tail(&led_cdev->node, &leds_list);
@@ -296,18 +570,22 @@ int of_led_classdev_register(struct device *parent, struct device_node *np,
 
 	led_update_brightness(led_cdev);
 
+	led_cdev->wq = leds_wq;
+
 	led_init_core(led_cdev);
 
 #ifdef CONFIG_LEDS_TRIGGERS
 	led_trigger_set_default(led_cdev);
 #endif
 
+	mutex_unlock(&led_cdev->led_access);
+
 	dev_dbg(parent, "Registered led device: %s\n",
 			led_cdev->name);
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(of_led_classdev_register);
+EXPORT_SYMBOL_GPL(led_classdev_register_ext);
 
 /**
  * led_classdev_unregister - unregisters a object of led_properties class.
@@ -317,6 +595,9 @@ EXPORT_SYMBOL_GPL(of_led_classdev_register);
  */
 void led_classdev_unregister(struct led_classdev *led_cdev)
 {
+	if (IS_ERR_OR_NULL(led_cdev->dev))
+		return;
+
 #ifdef CONFIG_LEDS_TRIGGERS
 	down_write(&led_cdev->trigger_lock);
 	if (led_cdev->trigger)
@@ -329,7 +610,8 @@ void led_classdev_unregister(struct led_classdev *led_cdev)
 	/* Stop blinking */
 	led_stop_software_blink(led_cdev);
 
-	led_set_brightness(led_cdev, LED_OFF);
+	if (!(led_cdev->flags & LED_RETAIN_AT_SHUTDOWN))
+		led_set_brightness(led_cdev, LED_OFF);
 
 	flush_work(&led_cdev->set_brightness_work);
 
@@ -352,14 +634,15 @@ static void devm_led_classdev_release(struct device *dev, void *res)
 }
 
 /**
- * devm_of_led_classdev_register - resource managed led_classdev_register()
+ * devm_led_classdev_register_ext - resource managed led_classdev_register_ext()
  *
  * @parent: parent of LED device
  * @led_cdev: the led_classdev structure for this device.
+ * @init_data: LED class device initialization data
  */
-int devm_of_led_classdev_register(struct device *parent,
-				  struct device_node *np,
-				  struct led_classdev *led_cdev)
+int devm_led_classdev_register_ext(struct device *parent,
+				   struct led_classdev *led_cdev,
+				   struct led_init_data *init_data)
 {
 	struct led_classdev **dr;
 	int rc;
@@ -368,7 +651,7 @@ int devm_of_led_classdev_register(struct device *parent,
 	if (!dr)
 		return -ENOMEM;
 
-	rc = of_led_classdev_register(parent, np, led_cdev);
+	rc = led_classdev_register_ext(parent, led_cdev, init_data);
 	if (rc) {
 		devres_free(dr);
 		return rc;
@@ -379,11 +662,11 @@ int devm_of_led_classdev_register(struct device *parent,
 
 	return 0;
 }
-EXPORT_SYMBOL_GPL(devm_of_led_classdev_register);
+EXPORT_SYMBOL_GPL(devm_led_classdev_register_ext);
 
 static int devm_led_classdev_match(struct device *dev, void *res, void *data)
 {
-	struct led_cdev **p = res;
+	struct led_classdev **p = res;
 
 	if (WARN_ON(!p || !*p))
 		return 0;
@@ -393,7 +676,7 @@ static int devm_led_classdev_match(struct device *dev, void *res, void *data)
 
 /**
  * devm_led_classdev_unregister() - resource managed led_classdev_unregister()
- * @parent: The device to unregister.
+ * @dev: The device to unregister.
  * @led_cdev: the led_classdev structure for this device.
  */
 void devm_led_classdev_unregister(struct device *dev,
@@ -407,17 +690,19 @@ EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
 
 static int __init leds_init(void)
 {
-	leds_class = class_create(THIS_MODULE, "leds");
-	if (IS_ERR(leds_class))
-		return PTR_ERR(leds_class);
-	leds_class->pm = &leds_class_dev_pm_ops;
-	leds_class->dev_groups = led_groups;
-	return 0;
+	leds_wq = alloc_ordered_workqueue("leds", 0);
+	if (!leds_wq) {
+		pr_err("Failed to create LEDs ordered workqueue\n");
+		return -ENOMEM;
+	}
+
+	return class_register(&leds_class);
 }
 
 static void __exit leds_exit(void)
 {
-	class_destroy(leds_class);
+	class_unregister(&leds_class);
+	destroy_workqueue(leds_wq);
 }
 
 subsys_initcall(leds_init);