[PATCH v3 4/4] backlight: pwm_bl: Set scale type for brightness curves specified in the DT

[Lee Jones]

On Tue, 09 Jul 2019, Matthias Kaehlcke wrote:

> Check if a brightness curve specified in the device tree is linear or
> not and set the corresponding property accordingly. This makes the
> scale type available to userspace via the 'scale' sysfs attribute.
> 
> To determine if a curve is linear it is compared to a interpolated linear
> curve between min and max brightness. The curve is considered linear if
> no value deviates more than +/-5% of ${brightness_range} from their
> interpolated value.
> 
> Signed-off-by: Matthias Kaehlcke <mka at chromium.org>
> Acked-by: Daniel Thompson <daniel.thompson at linaro.org>
> ---
> Changes in v3:
> - none
> 
> Changes in v2:
> - use 128 (power of two) instead of 100 as factor for the slope
> - add comment about max quantization error
> - added Daniel's 'Acked-by' tag
> ---
>  drivers/video/backlight/pwm_bl.c | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)

Applied, thanks.

-- 
Lee Jones [李琼斯]
Linaro Services Technical Lead
Linaro.org │ Open source software for ARM SoCs
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