On Mon, Mar 19, 2018 at 05:04:31PM +0100, Enric Balletbo Serra wrote: > Hi Daniel, > > Gentle ping for this series, there is any possibility you have a > chance to review it? Let me know if you want I change something. I haven't got it in my TODO backlog... which means either I mistakenly deleted it when it went through originally or that I deliberately deleted it because I thought a v4 was coming along soon. I could go diving through the archives if I need to but were there other pending changes for this patchset? Daniel. > > Thanks, > Enric > > 2018-02-08 12:30 GMT+01:00 Enric Balletbo i Serra > <enric.balletbo@xxxxxxxxxxxxx>: > > Dear all, > > > > This series is a third patchset integrating the requested changes. > > > > The first and second patch what tries to solve is the problem of > > granularity for high resolution PWMs. The idea is simple interpolate > > between 2 brightness values so we can have a high PWM duty cycle (a > > 16 bits PWM is up to 65535 possible steps) without having to list > > out every possible value in the dts. I think that this patch is > > required to not break backward compability, to be more flexible and > > also extend the functionality to be able to use high resolution PWM > > with enough steps to have a good UI experience in userspace. > > > > The thirth and fourth patch is a bit more ambicious, the idea is let > > decide the driver the brightness-levels required in function of the PWM > > resolution. To do this create a brightness-levels table filled with the > > CIE 1931 algorithm values to convert brightness to PWM duty cycle. > > > > More detailed info is available in the commit message of every patch. > > > > Both functionalities were tested on a Samsung Chromebook Plus (that has > > a 16 bits PWM) and a SL50 device (with a 8 bits PWM) > > > > Waiting for your feedback. > > > > Best regards, > > > > Enric Balletbo i Serra (4): > > backlight: pwm_bl: linear interpolation between brightness-levels > > dt-bindings: pwm-backlight: add a num-interpolation-steps property. > > backlight: pwm_bl: compute brightness of LED linearly to human eye. > > dt-bindings: pwm-backlight: move brightness-levels to optional. > > > > .../bindings/leds/backlight/pwm-backlight.txt | 34 ++- > > drivers/video/backlight/pwm_bl.c | 232 +++++++++++++++++++-- > > 2 files changed, 246 insertions(+), 20 deletions(-) > > > > -- > > 2.15.1 > >
