On Fri 2019-03-08 13:38:02, Nick Crews 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 Can you make it "platform::kbd_backlight"? We want some consistency there. > 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. Good. > When the EC is reset (loses all AC and battery power), it will > restart in some unpredictable state. The brightness on the > keyboard could be anything, and reading the brightness > from the EC is undefined behavior. Therefore, at startup the > brightness should be set, and then everything will work. Really? Undefined behavior? > index e09e4cebe9b4..15b56f5ce090 100644 > --- a/drivers/platform/chrome/wilco_ec/Kconfig > +++ b/drivers/platform/chrome/wilco_ec/Kconfig > @@ -18,3 +18,12 @@ config WILCO_EC_DEBUGFS > manipulation and allow for testing arbitrary commands. This > interface is intended for debug only and will not be present > on production devices. > + > +config WILCO_EC_KBD_BACKLIGHT > + tristate "Enable keyboard led backlight control" Delete "led" or make it "LED". > + depends on WILCO_EC > + help > + If you say Y here, you get support to set the keyboard backlight led Same here. > +#define DRV_NAME "wilco-kbd-backlight" > + > +#define EC_COMMAND_KB_BKLIGHT 0x75 > +#define KBBL_MSG_SIZE 16 > +/* The EC can set the backlight brightness in several different modes. > +The mode we care about is PWM mode, where we separately supply a > +literal percentage to set the brightness to. We need to set the proper > +KBBL_PWM_MODE flag in the KBBL_MODE_INDEX-th byte in the message, and > +then supply the percentage within the KBBL_BRIGHTNESS_INDEX-th byte > +within the message. When we read the brightness, the percentage is > +returned in this same byte location. */ Please use comment style specified in CodingStyle. Best regards, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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