Commit 699a8c7c authored by Tomi Valkeinen's avatar Tomi Valkeinen Committed by Pavel
Browse files

leds: Add of_led_get() and led_put() 



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: default avatarTomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: default avatarJean-Jacques Hiblot <jjhiblot@ti.com>
Acked-by: default avatarPavel Machek <pavel@ucw.cz>
Signed-off-by: default avatarPavel Machek <pavel@ucw.cz>
parent 31e065c4

drivers/leds/led-class.c

+44 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#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;
@@ -214,6 +215,49 @@ static int led_resume(struct device *dev) 


static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);



/**

 * 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_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;

}

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 led_classdev_next_name(const char *init_name, char *name,

				  size_t len)

{

include/linux/leds.h

+4 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 


struct device;

struct led_pattern;

struct device_node;

/*

 * LED Core

 */
@@ -196,6 +197,9 @@ void devm_led_classdev_unregister(struct device *parent, 
void led_classdev_suspend(struct led_classdev *led_cdev);

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

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