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Diffstat (limited to 'drivers/leds/led-class.c')
-rw-r--r--drivers/leds/led-class.c122
1 files changed, 94 insertions, 28 deletions
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
index 6dae56b914fe..885399ed0776 100644
--- a/drivers/leds/led-class.c
+++ b/drivers/leds/led-class.c
@@ -22,19 +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,
@@ -58,7 +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:
@@ -71,14 +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,
};
@@ -114,7 +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);
@@ -234,30 +242,42 @@ static struct led_classdev *led_module_get(struct device *led_dev)
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 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);
- put_device(led_dev);
return led_module_get(led_dev);
}
-EXPORT_SYMBOL_GPL(of_led_get);
/**
* led_put() - release a LED device
@@ -312,7 +332,7 @@ struct led_classdev *__must_check devm_of_led_get(struct device *dev,
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;
@@ -330,9 +350,14 @@ EXPORT_SYMBOL_GPL(devm_of_led_get);
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)) &&
@@ -346,7 +371,7 @@ struct led_classdev *led_get(struct device *dev, char *con_id)
if (!provider)
return ERR_PTR(-ENOENT);
- led_dev = class_find_device_by_name(leds_class, provider);
+ led_dev = class_find_device_by_name(&leds_class, provider);
kfree_const(provider);
return led_module_get(led_dev);
@@ -402,6 +427,31 @@ void led_remove_lookup(struct led_lookup_data *led_lookup)
}
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)
{
@@ -412,7 +462,7 @@ static int led_classdev_next_name(const char *init_name, char *name,
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);
}
@@ -457,6 +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;
@@ -465,11 +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);
@@ -477,10 +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) {
@@ -508,6 +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
@@ -626,17 +690,19 @@ EXPORT_SYMBOL_GPL(devm_led_classdev_unregister);
static int __init leds_init(void)
{
- leds_class = class_create("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);
generated by cgit (git 2.34.1) at 2025-12-24 19:59:56 +0000