From: Tomi Valkeinen tomi.valkeinen@ti.com
This patch adds basic support for a kernel driver to get a LED device. This will be used by the led-backlight driver.
Only OF version is implemented for now, and the behavior is similar to PWM's of_pwm_get() and pwm_put().
Signed-off-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com --- drivers/leds/led-class.c | 50 ++++++++++++++++++++++++++++++++++++++++ include/linux/leds.h | 4 ++++ 2 files changed, 54 insertions(+)
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index cadd43c30d50..9f48798a713d 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -18,6 +18,7 @@ #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; @@ -213,6 +214,55 @@ static int led_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);
+static int led_match_led_node(struct device *led_dev, const void *data) +{ + return led_dev->of_node == data; +} + +/** + * 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 + * + * 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) +{ + struct device *led_dev; + struct led_classdev *led_cdev; + struct device_node *led_node; + + led_node = of_parse_phandle(np, "leds", index); + if (!led_node) + return ERR_PTR(-ENOENT); + + led_dev = class_find_device(leds_class, NULL, led_node, + led_match_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; +} +EXPORT_SYMBOL_GPL(of_led_get); + +/** + * 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); +} +EXPORT_SYMBOL_GPL(led_put); + static int match_name(struct device *dev, const void *data) { if (!dev_name(dev)) diff --git a/include/linux/leds.h b/include/linux/leds.h index bee8e3f8dddd..0a71c7cdd191 100644 --- a/include/linux/leds.h +++ b/include/linux/leds.h @@ -19,6 +19,7 @@
struct device; struct led_pattern; +struct device_node; /* * LED Core */ @@ -145,6 +146,9 @@ extern void devm_led_classdev_unregister(struct device *parent, extern void led_classdev_suspend(struct led_classdev *led_cdev); extern void led_classdev_resume(struct led_classdev *led_cdev);
+extern struct led_classdev *of_led_get(struct device_node *np, int index); +extern void led_put(struct led_classdev *led_cdev); + /** * led_blink_set - set blinking with software fallback * @led_cdev: the LED to start blinking