Re: [PATCH v3 2/5] leds: Add helper for getting default pattern from Device Tree

[Pavel Machek]

On Wed 2018-12-12 12:16:43, Krzysztof Kozlowski wrote:
> Multiple LED triggers might need to access default pattern so add a
> helper for that.
> 
> Signed-off-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>

Acked-by: Pavel Machek <pavel@xxxxxx>

> 
> New patch in the series
> 
> ---
>  drivers/leds/led-class.c | 25 +++++++++++++++++++++++++
>  include/linux/leds.h     |  3 +++
>  2 files changed, 28 insertions(+)
> 
> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> index 3c7e3487b373..44b95e6480f6 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -17,6 +17,7 @@
>  #include <linux/leds.h>
>  #include <linux/list.h>
>  #include <linux/module.h>
> +#include <linux/of.h>
>  #include <linux/slab.h>
>  #include <linux/spinlock.h>
>  #include <linux/timer.h>
> @@ -244,6 +245,30 @@ static int led_classdev_next_name(const char *init_name, char *name,
>  }
>  
>  /**
> + * led_classdev_get_default_pattern - return default pattern
> + *
> + * @led_cdev: the led_classdev structure for this device
> + *
> + * Return: Null terminated string with default pattern from DeviceTree or NULL
> + */

Is it valid kerneldoc? Note that core still owns the string so that
caller is not expected to free it?

> +const char *led_classdev_get_default_pattern(struct led_classdev *led_cdev)
> +{
> +	struct device_node *np = dev_of_node(led_cdev->dev);
> +	const char *pattern;
> +
> +	if (!np)
> +		return NULL;
> +
> +	if (of_property_read_string(np, "led-pattern", &pattern))
> +		return NULL;
> +
> +	if (!strlen(pattern))
> +		return NULL;
> +
> +	return pattern;
> +}
> +
> +/**
>   * of_led_classdev_register - register a new object of led_classdev class.
>   *
>   * @parent: parent of LED device
> diff --git a/include/linux/leds.h b/include/linux/leds.h
> index 5263f87e1d2c..9da2bfa183ea 100644
> --- a/include/linux/leds.h
> +++ b/include/linux/leds.h
> @@ -129,6 +129,9 @@ struct led_classdev {
>  	struct mutex		led_access;
>  };
>  
> +extern const char *
> +led_classdev_get_default_pattern(struct led_classdev *led_cdev);
> +
>  extern int of_led_classdev_register(struct device *parent,
>  				    struct device_node *np,
>  				    struct led_classdev *led_cdev);

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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