# Re: \[PATCH v3 2/3\] arm64: dts: qcom: trogdor: Add brightness-levels

- From: Doug Anderson \<dianders@chromium.org\>
- Date: 2020-10-22 23:08:14 
- List: linux-devicetree
- Page: https://ratatoskr.run/linux-devicetree/2020/10/6147228
- Thread: https://ratatoskr.run/linux-devicetree/2020/10/6146361/t.md

```text
Hi,

On Wed, Oct 21, 2020 at 10:05 PM Alexandru Stan [ref] wrote:
>
> We want userspace to represent the human perceived brightness.
> Since the led drivers and the leds themselves don't have a
> linear response to the value we give them in terms of perceived
> brightness, we'll bake the curve into the dts.
>
> The panel also doesn't have a good response under 5%, so we'll avoid
> sending it anything lower than that.
>
> Note: Ideally this patch should be coupled with the driver change from
> "backlight: pwm_bl: Fix interpolation", but it can work without it,
> without looking too ugly.
>
> Signed-off-by: Alexandru Stan <redacted>
> ---
>
>  arch/arm64/boot/dts/qcom/sc7180-trogdor.dtsi | 9 +++++++++
>  1 file changed, 9 insertions(+)

Reviewed-by: Douglas Anderson <dianders@chromium.org>
```