> > > 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. Good point Dmitry. I would imagine this would entail exposing the keyboard_leds_exist() function. What is the best practice for doing that? I could either imagine EXPORT_SYMBOL_GPL()ing that function, but that would require making the core driver dependent upon this keyboard backlight driver in a circular dependency, so there would have to be some refactoring. The other option I see would be to add this entire driver to the core module. Just so I learn something, I don't see performance or stability concerns with adding one unused platform device, is your rationale that it would just be cleaner code? > > > > > + 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. Yes, thanks for the catch. > > Hmm. Seeing get method there... can the EC change the brightness > without command from kernel? No, the EC will never do that, good point. Therefore it looks like I can just remove the get_brightness() function and the core library will do the right thing. Thanks, Nick
