[PATCH] ARM: DTS: omap4-sdp: Add regulator for LCD backlight (pwm-backlight)

Sourav Poddar sourav.poddar at ti.com
Thu Nov 28 05:09:17 EST 2013


On Thursday 28 November 2013 02:58 PM, Peter Ujfalusi wrote:
> Since in DT booted kernel dummy regulators are no longer supported we need
> to provide valid phandle for the regulator needed by the backlight.
> On the board VBAT is used to power the LCD backlight(s).
>
> Signed-off-by: Peter Ujfalusi<peter.ujfalusi at ti.com>
> ---
> Hi,
>
> This patch is needed for 3.13 to get the LCD backlight to work again.
Is this usage of power supply a mandatory requirement?

There is a thread which discusses this issue[1]:
http://www.spinics.net/lists/arm-kernel/msg288215.html

According to the above, regulator framework have support in 3.13-rc1 to 
returns
a dummy  regulator if there is none specified in the dts data.
Thierry told that there seems to be a bug in regulator in handling these 
case.

Though, I also posted a patch on pwm a couple of days ago[2]
[2]: https://patchwork.kernel.org/patch/3246711/

I posted it without "power-supply" by testing it with the
solution proposed in [1].
If I dont use the solution[1], it fails for me also.




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