Hi, On Thu, Oct 03, 2019 at 10:28:09AM +0200, Jean-Jacques Hiblot wrote: > From: Tomi Valkeinen <[email protected]> > > 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 <[email protected]> > Signed-off-by: Jean-Jacques Hiblot <[email protected]> > Acked-by: Pavel Machek <[email protected]> > --- > drivers/leds/led-class.c | 44 ++++++++++++++++++++++++++++++++++++++++ > include/linux/leds.h | 4 ++++ > 2 files changed, 48 insertions(+) > > diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c > index c2167b66b61f..455545f5d663 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);
If you convert led_node into a fwnode, you can use
class_find_device_by_fwnode() instead. That way the
first patch can just be dropped.
-- Sebastian
> + 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)
> {
> diff --git a/include/linux/leds.h b/include/linux/leds.h
> index b8df71193329..6f7371bc7757 100644
> --- a/include/linux/leds.h
> +++ b/include/linux/leds.h
> @@ -20,6 +20,7 @@
>
> struct device;
> struct led_pattern;
> +struct device_node;
> /*
> * LED Core
> */
> @@ -196,6 +197,9 @@ 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
> --
> 2.17.1
>
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