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| author | Tomi Valkeinen <tomi.valkeinen@ti.com> | 2019-10-03 10:28:09 +0200 |
|---|---|---|
| committer | Pavel <pavel@ucw.cz> | 2020-01-06 00:20:06 +0100 |
| commit | 699a8c7c4bd376aee4808e6272188319e900c8af (patch) | |
| tree | b35f95250a065850ed2a35cf22ceb0209fc4c164 /drivers/leds | |
| parent | 31e065c4e8bac71be29a9d4d65ea62f5c9ec17b3 (diff) | |
| download | linux-rt-699a8c7c4bd376aee4808e6272188319e900c8af.tar.gz | |
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: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
Diffstat (limited to 'drivers/leds')
| -rw-r--r-- | drivers/leds/led-class.c | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c index 438774315e6c..03ce74a2e6a9 100644 --- a/drivers/leds/led-class.c +++ b/drivers/leds/led-class.c @@ -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) { |