Hi, On Wed, Dec 03, 2014 at 06:41:33PM +0100, Gabriele Mazzotta wrote: > Add the documentation for the new sysfs interface of dell-laptop > that allows to configure the keyboard illumination on Dell systems. > > Signed-off-by: Gabriele Mazzotta <gabriele.mzt@xxxxxxxxx> > Signed-off-by: Pali Rohár <pali.rohar@xxxxxxxxx> > --- > .../ABI/testing/sysfs-platform-dell-laptop | 60 ++++++++++++++++++++++ > 1 file changed, 60 insertions(+) > create mode 100644 Documentation/ABI/testing/sysfs-platform-dell-laptop > > diff --git a/Documentation/ABI/testing/sysfs-platform-dell-laptop b/Documentation/ABI/testing/sysfs-platform-dell-laptop > new file mode 100644 > index 0000000..7969443 > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-platform-dell-laptop > @@ -0,0 +1,60 @@ > +What: /sys/class/leds/dell::kbd_backlight/als_setting > +Date: December 2014 > +KernelVersion: 3.19 > +Contact: Gabriele Mazzotta <gabriele.mzt@xxxxxxxxx>, > + Pali Rohár <pali.rohar@xxxxxxxxx> > +Description: > + This file allows to control the automatic keyboard > + illumination mode on some systems that have an ambient > + light sensor. Write 1 to this file to enable the auto > + mode, 0 to disable it. [...] This entry appears wrong, or at least incomplete. My system boots with a default value of 18, and the 'set' implementation accepts any value from 0 to 255. According to the comments in dell-laptop.c, the value actually means something different than on/off: cbArg3, byte0 Desired setting of ALS value that turns the light on or off. Admittedly, I'm not clear on what the intended interface is, as I've never had the ALS / keyboard backlight controls all working properly on my laptop in the first place, but I thought this would be the right place to ask about getting the documentation and driver in sync. NB: I came across this because (1) I'd really like to be able to turn the keyboard backlight on, the timeout off, and the ALS off; and (2) I noticed there was a new driver patch in 3.19 (nice! thanks!), where previously there must have been some kind of half-functional working driver -- I could get backlight control, but it always timed out too quickly. It seems like /sys/.../als_setting is documented to handle the latter part of (1), but its implementation does not match. Thanks, Brian P.S. The author of this page [1] might be interested in these new driver additions. [1] http://www.cs.bham.ac.uk/~axs/laptop/dell-e6410-fn-keys.html -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
