1 files changed, 211 insertions, 46 deletions

diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 6a8ea94834fa..885399ed0776 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -22,17 +22,23 @@
 #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,
@@ -56,7 +62,6 @@ static ssize_t brightness_store(struct device *dev,
 	if (state == LED_OFF)
 		led_trigger_remove(led_cdev);
 	led_set_brightness(led_cdev, state);
-	flush_work(&led_cdev->set_brightness_work);
 
 	ret = size;
 unlock:
@@ -69,14 +74,19 @@ 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 BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
-static struct bin_attribute *led_trigger_bin_attrs[] = {
+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,
 };
@@ -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);
@@ -215,38 +225,59 @@ static int led_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
 
+static struct led_classdev *led_module_get(struct device *led_dev)
+{
+	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.
  */
-struct led_classdev *of_led_get(struct device_node *np, int index)
+static struct led_classdev *of_led_get(struct device_node *np, int index,
+				       const char *name)
 {
 	struct device *led_dev;
-	struct led_classdev *led_cdev;
 	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);
+	led_dev = class_find_device_by_of_node(&leds_class, led_node);
 	of_node_put(led_node);
 
-	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))
-		return ERR_PTR(-ENODEV);
-
-	return led_cdev;
+	return led_module_get(led_dev);
 }
-EXPORT_SYMBOL_GPL(of_led_get);
 
 /**
  * led_put() - release a LED device
@@ -255,6 +286,7 @@ EXPORT_SYMBOL_GPL(of_led_get);
 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);
 
@@ -265,6 +297,22 @@ static void devm_led_release(struct device *dev, void *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
@@ -280,28 +328,129 @@ struct led_classdev *__must_check devm_of_led_get(struct device *dev,
 						  int index)
 {
 	struct led_classdev *led;
-	struct led_classdev **dr;
 
 	if (!dev)
 		return ERR_PTR(-EINVAL);
 
-	led = of_led_get(dev->of_node, index);
+	led = of_led_get(dev->of_node, index, NULL);
 	if (IS_ERR(led))
 		return led;
 
-	dr = devres_alloc(devm_led_release, sizeof(struct led_classdev *),
-			  GFP_KERNEL);
-	if (!dr) {
-		led_put(led);
-		return ERR_PTR(-ENOMEM);
+	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);
 
-	*dr = led;
-	devres_add(dev, dr);
+	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);
+EXPORT_SYMBOL_GPL(devm_of_led_get_optional);
 
 static int led_classdev_next_name(const char *init_name, char *name,
 				  size_t len)
@@ -310,10 +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_by_name(leds_class, name))) {
+	       (dev = class_find_device_by_name(&leds_class, name))) {
 		put_device(dev);
 		ret = snprintf(name, len, "%s_%u", init_name, ++i);
 	}
@@ -358,6 +507,14 @@ int led_classdev_register_ext(struct device *parent,
 			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;
@@ -366,11 +523,19 @@ int led_classdev_register_ext(struct device *parent,
 	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);
+
+	if (led_cdev->color >= LED_COLOR_ID_MAX)
+		dev_warn(parent, "LED %s color identifier out of range\n", final_name);
 
 	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);
+	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);
@@ -378,10 +543,6 @@ int led_classdev_register_ext(struct device *parent,
 	if (init_data && init_data->fwnode)
 		device_set_node(led_cdev->dev, init_data->fwnode);
 
-	if (ret)
-		dev_warn(parent, "Led %s renamed to %s due to name collision",
-				proposed_name, dev_name(led_cdev->dev));
-
 	if (led_cdev->flags & LED_BRIGHT_HW_CHANGED) {
 		ret = led_add_brightness_hw_changed(led_cdev);
 		if (ret) {
@@ -409,6 +570,8 @@ int led_classdev_register_ext(struct device *parent,
 
 	led_update_brightness(led_cdev);
 
+	led_cdev->wq = leds_wq;
+
 	led_init_core(led_cdev);
 
 #ifdef CONFIG_LEDS_TRIGGERS
@@ -527,17 +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);