Dear all, This patch series is a first RFC to know your opinion about implement support to create brightness levels tables dinamically. I tried to argue in every patch the specific reasons we think this can be interesting, to sumup, the idea behind these patches is be able to pass via device tree two parameters to the driver so it can calculate the brightness levels based on the CIE 1931 lightness formula, which is what actually describes how we perceive light. I think that at least the maths involved can be improved, and I've still some doubts. With current code if you create a table with a max PWM value of 255 and 127 steps, the first numbers are repeated so I'm thinking that maybe we should skip/remove the repeated values. i.e. have a table like this, [0, 1, 2, 3 ... 235, 240, 245, 250, 255] instead of [0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3 ... 235, 240, 245, 250, 255] Well, I know there are things to improve but lets see your feedback first before dedicate more time on it. The patches were tested on a couple of devices but I'll test on more devices meanwhile we discuss about it. Best regards, Enric Balletbo i Serra (2): dt-bindings: pwm-backlight: add brightness-levels-scale property backlight: pwm_bl: compute brightness of LED linearly to human eye. .../bindings/leds/backlight/pwm-backlight.txt | 21 ++++ drivers/video/backlight/pwm_bl.c | 111 +++++++++++++++++++-- 2 files changed, 123 insertions(+), 9 deletions(-) -- 2.9.3 -- 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
