@@ -59,6 +59,15 @@ Description:
brightness. Reading this file when no hw brightness change
event has happened will return an ENODATA error.
+What: /sys/class/leds/<led>/color
+Date: October 2022
+KernelVersion: 6.1
+Description:
+ Color of the led.
+
+ This is a read-only file. Reading this file returns the color
+ of the led as a string (ex: "red", "green").
+
What: /sys/class/leds/<led>/trigger
Date: March 2006
KernelVersion: 2.6.17
@@ -74,6 +74,18 @@ static ssize_t max_brightness_show(struct device *dev,
}
static DEVICE_ATTR_RO(max_brightness);
+static ssize_t color_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ const char *color_text = "invalid";
+ struct led_classdev *led_cdev = dev_get_drvdata(dev);
+
+ if (led_cdev->color < LED_COLOR_ID_MAX)
+ color_text = led_colors[led_cdev->color];
+ return sysfs_emit(buf, "%s\n", color_text);
+}
+static DEVICE_ATTR_RO(color);
+
#ifdef CONFIG_LEDS_TRIGGERS
static BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);
static struct bin_attribute *led_trigger_bin_attrs[] = {
@@ -88,6 +100,7 @@ static const struct attribute_group led_trigger_group = {
static struct attribute *led_class_attrs[] = {
&dev_attr_brightness.attr,
&dev_attr_max_brightness.attr,
+ &dev_attr_color.attr,
NULL,
};
@@ -375,6 +388,10 @@ 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;
+
+ 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;
@@ -384,6 +401,9 @@ int led_classdev_register_ext(struct device *parent,
if (ret < 0)
return ret;
+ 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,
@@ -71,6 +71,7 @@ struct led_classdev {
const char *name;
unsigned int brightness;
unsigned int max_brightness;
+ unsigned int color;
int flags;
/* Lower 16 bits reflect status */
This information might be useful for more than only deriving the led's name. And since we have this information, we can expose it in the sysfs. Signed-off-by: Jean-Jacques Hiblot <jjhiblot@traphandler.com> --- Documentation/ABI/testing/sysfs-class-led | 9 +++++++++ drivers/leds/led-class.c | 20 ++++++++++++++++++++ include/linux/leds.h | 1 + 3 files changed, 30 insertions(+)