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 <gre...@linuxfoundation.org> > Cc: "Rafael J. Wysocki" <raf...@kernel.org> > Cc: Jacek Anaszewski <jacek.anaszew...@gmail.com> > Cc: Pavel Machek <pa...@ucw.cz> > Cc: Dan Murphy <dmur...@ti.com> > Signed-off-by: Akinobu Mita <akinobu.m...@gmail.com> > --- > 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-l...@vger.kernel.org > +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