Re: [PATCH] platform/chrome: Add Wilco EC keyboard backlight LEDs support

[Dmitry Torokhov]

On Fri, Mar 8, 2019 at 12:41 PM Nick Crews <ncrews@xxxxxxxxxxxx> wrote:
>
> This patch is meant to be applied on top of the for-next
> branch of the platform/chrome repository, as it uses some of
> the code staged there.
>
> 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/wilco::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 in probe(), and in this case the sysfs entry will
> not appear, and everything will behave normally.

It would be even better if we did not register platform device if EC
does not support backlight.

> +       data->led.brightness_set = keyboard_led_set_brightness;
> +       data->led.brightness_get = keyboard_led_get_brightness;

wilco_ec_mailbox() may sleep, so you need to assign it to
led.brightness_set_blocking.

Thanks,
Dmitry