[lkml]   [2019]   [Apr]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [PATCH v5 2/3] platform/chrome: Add Wilco EC keyboard backlight LEDs support
On Thu 2019-04-04 11:10:08, 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.
> Signed-off-by: Nick Crews <>
> Acked-by: Jacek Anaszewski <>

Acked-by: Pavel Machek <>

(cesky, pictures)
[unhandled content-type:application/pgp-signature]
 \ /
  Last update: 2019-04-04 21:53    [W:0.118 / U:1.104 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site