Re: [PATCH 1/9] dt-bindings: pwm: marvell,pxa: add optional property resets

[Uwe Kleine-König]

Hello Alex,

On Wed, Apr 16, 2025 at 06:33:42AM -0500, Alex Elder wrote:
> On 4/16/25 12:18 AM, Uwe Kleine-König wrote:
> > Hello,
> > 
> > On Tue, Apr 15, 2025 at 12:28:07PM +0000, Yixun Lan wrote:
> > > maybe there are cases that users don't want to issue a reset..
> > > so, want to make it optional.. I can think one example that,
> > > display controller is up and working from bootloader to linux,
> > > reset it will got a flicker picture..
> > 
> > Agreed. You can just deassert the reset at probe time. That shouldn't
> > interfere with a PWM that is already producing an output.
> 
> I think you're saying reset can be a required property, to be
> harmlessly deasserted at probe time?  Yixun was suggesting it
> should not be required, because it might already be deasserted.
> 
> Anyway, I don't feel strongly either way.  Maybe the DTS
> maintainers can recommend what to do.

IMHO you shouldn't have to modify the dts if you want to initialize a
display in the bootloader and than boot flicker-free into Linux.

If the only thing you do with the reset is
devm_reset_control_get_optional_shared_deasserted() (or a variant of
it), everything should work just fine.

I'm not a DTS maintainer, but still have my opinion and recommend that.
:-)

Best regards
Uwe

Attachment: signature.asc
Description: PGP signature