# Re: \[PATCH 4/4\] pwm\_backlight: Add support for the whole range of the PWM in DT mode

- From: Thierry Reding \<hidden\>
- Date: 2013-01-29 10:01:14 
- List: linux-fbdev
- Page: https://ratatoskr.run/linux-fbdev/2013/01/3992647
- Thread: https://ratatoskr.run/linux-fbdev/2013/01/3988271/t.md

```text
On Tue, Jan 22, 2013 at 02:39:56PM +0100, Peter Ujfalusi wrote:
> When booting with DT make it possible to use the whole range of the PWM when
> controlling the backlight in a same way it is possible when the kernel is
> booted in non DT mode.
> A new property "max-brightness-level" can be used to specify the maximum
> value the PWM can handle (time slots).
> DTS files can use either the "brightness-levels" or the "max-brightness-level"
> to configure the PWM.
> In case both of these properties exist the driver will prefer the
> "brightness-levels" over the "max-brightness-level".
> 
> Signed-off-by: Peter Ujfalusi <redacted>

I don't think this is a good idea. The brightness-levels property was
specifically introduced in order to have a more reasonable interface to
specify brightness levels.

As such, all uses of the non-DT max_brightness to be deprecated. It is
only kept for backwards compatibility with non-DT boards.

Thierry
```

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