[PATCH 1/9] dt-bindings: pwm: marvell,pxa: add optional property resets
Uwe Kleine-König
ukleinek at kernel.org
Wed Apr 16 07:56:19 PDT 2025
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
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