Re: [PATCH 5/5] leds: add /sys/class/leds/<led>/current-trigger

[Greg Kroah-Hartman]

On Sun, Sep 08, 2019 at 09:41:12PM +0900, Akinobu Mita wrote:
> Reading /sys/class/leds/<led>/trigger returns all available LED triggers.
> However, this violates the "one value per file" rule of sysfs.
> 
> This provides /sys/class/leds/<led>/current-trigger which is almost
> identical to /sys/class/leds/<led>/trigger.  The only difference is that
> 'current-trigger' only shows the current trigger name.
> 
> This new file follows the "one value per file" rule of sysfs.
> We can use the /sys/class/triggers directory to get the list of available
> LED triggers.
> 
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
> Cc: Jacek Anaszewski <jacek.anaszewski@xxxxxxxxx>
> Cc: Pavel Machek <pavel@xxxxxx>
> Cc: Dan Murphy <dmurphy@xxxxxx>
> Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
> ---
>  Documentation/ABI/testing/sysfs-class-led | 13 +++++++++++
>  drivers/leds/led-class.c                  |  7 ++++++
>  drivers/leds/led-triggers.c               | 38 +++++++++++++++++++++++++++----
>  drivers/leds/leds.h                       |  5 ++++
>  4 files changed, 59 insertions(+), 4 deletions(-)
> 
> diff --git a/Documentation/ABI/testing/sysfs-class-led b/Documentation/ABI/testing/sysfs-class-led
> index 14d91af..1a1be10 100644
> --- a/Documentation/ABI/testing/sysfs-class-led
> +++ b/Documentation/ABI/testing/sysfs-class-led
> @@ -70,3 +70,16 @@ Description:
>  		This directory contains a number of sub-directories, each
>  		representing an LED trigger. The name of the sub-directory
>  		matches the LED trigger name.
> +
> +What:		/sys/class/leds/<led>/current-trigger
> +Date:		September 2019
> +KernelVersion:	5.5
> +Contact:	linux-leds@xxxxxxxxxxxxxxx
> +Description:
> +		Set the trigger for this LED. A trigger is a kernel based source
> +		of LED events.
> +		Writing the trigger name to this file will change the current
> +		trigger. Trigger specific parameters can appear in
> +		/sys/class/leds/<led> once a given trigger is selected. For
> +		their documentation see sysfs-class-led-trigger-*.
> +		Reading this file will return the current LED trigger name.
> diff --git a/drivers/leds/led-class.c b/drivers/leds/led-class.c
> index 04e6c14..388500b 100644
> --- a/drivers/leds/led-class.c
> +++ b/drivers/leds/led-class.c
> @@ -73,12 +73,19 @@ static ssize_t max_brightness_show(struct device *dev,
>  static DEVICE_ATTR_RO(max_brightness);
>  
>  #ifdef CONFIG_LEDS_TRIGGERS
> +static DEVICE_ATTR(current_trigger, 0644, led_current_trigger_show,
> +		   led_current_trigger_store);

DEVICE_ATTR_RW()?


> +static struct attribute *led_current_trigger_attrs[] = {
> +	&dev_attr_current_trigger.attr,
> +	NULL,
> +};
>  static BIN_ATTR(trigger, 0644, led_trigger_read, led_trigger_write, 0);

BIN_ATTR_RW()?

And no whitespace?

thanks,

gre gk-h