On Friday, November 17, 2017 6:21 AM, Pavel Machek wrote: > > Hi! > > > >> If that does not yet exist... you want to create glue layer to be > able > > >> to use LED as a display backlight. (It may already exist, no idea). > > >> > > >> ... > > >> > > >> Actually or maybe a LED trigger. Just set LED's trigger to "this is > > >> display backlight". > > > > > > There is one already: > > > > > > drivers/leds/trigger/ledtrig-backlight.c > > > > > > It adds a LED class device to the fb_notifier_list > > > (drivers/video/fbdev/core/fb_notify.c) > > > > > > using fb_register_client(). The same is used in > > > backlight_device_register (drivers/video/backlight/backlight.c). > > > > > > Actually why do you want to have this driver in the LED subsystem, > > > if it is advertised as "designed for LCD display backlighting"? > > > > Well this is also advertised as a driver for Smart phone and tablet > devices. And having worked with the Android lighting > > solutions this is the preferred subsystem for Android. The Android OS > manages the led brightness based on ALS values and in > > turn calls into the driver to control the brightness register through > the vendor provided lighting HAL. > > > > Well.. if it can control other LEDs than just backlight, I believe it > can stay in the LED subsystem. I also agree with your opinion. Best regards, Jingoo Han > > > I am going to look at the backlight source to figure out how to get the > same functionality using the backlight subsystem. > > Otherwise I will plug in this driver to the backlight subsystem through > the notifier. > > > > The backlight trigger should be ok. > > Best regards, > Pavel > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) > http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
