On Fri 2019-04-05 13:15:34, Guenter Roeck wrote: > On Thu, Apr 04, 2019 at 11:10:08AM -0600, Nick Crews wrote: > > The EC is in charge of controlling the keyboard backlight on > > the Wilco platform. We expose a standard LED class device at > > /sys/class/leds/platform::kbd_backlight. This driver is modeled > > after the standard Chrome OS keyboard backlight driver at > > drivers/platform/chrome/cros_kbd_led_backlight.c > > > > Some Wilco devices do not support a keyboard backlight. This > > is checked via wilco_ec_keyboard_leds_exist() in the core driver, > > and a platform_device will only be registered by the core if > > a backlight is supported. > > > > After an EC reset the backlight could be in a non-PWM mode. > > Earlier in the boot sequence the BIOS should send a command to > > the EC to set the brightness, so things **should** be set up, > > but we double check in probe() as we query the initial brightness. > > If not set up, then set the brightness to 0. > > > > Since the EC will never change the backlight level of its own accord, > > we don't need to implement a brightness_get() method. > > > > v5 changes: > > -Rename the LED device to "platform::kbd_backlight", to > > denote that this is the built-in system keyboard. > > > > NACK. Please keep it as it is, it is okay. > Per Documentation/leds/leds-class.txt, LED devices are named > "devicename:colour:function" You failed to follow threads explaining this is being changed, even when I pointed you at them. What you are doing here is not helpful. > This document also states "The naming scheme above leaves scope > for further attributes should they be needed". It does not permit, > however, to redefine one of the fields to mean "location", much less > the declaration that a devicename of "platform" shall refer to an > "internal" backlight, or that there shall be no more than one > "internal" backlight in a given system. "platform" is as good devicename as "wilco" or "chromeos". Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html