[PATCH v2 1/2] dt-bindings: wkup-m3-ipc: Add vtt toggle gpio pin property

[Drew Fustini]

On Tue, Apr 12, 2022 at 02:54:27PM -0500, Rob Herring wrote:
> On Sat, Apr 09, 2022 at 02:12:14PM -0700, Drew Fustini wrote:
> > Document Wakeup M3 IPC property that indicates a GPIO pin is connected
> > to the enable pin on DDR VTT regulator and can be toggled during low
> > power mode transitions.
> > 
> > Signed-off-by: Dave Gerlach <d-gerlach at ti.com>
> > [dfustini: converted to YAML, removed unnecessary "ti,needs-vtt-toggle"]
> > Signed-off-by: Drew Fustini <dfustini at baylibre.com>
> > ---
> >  .../devicetree/bindings/soc/ti/wkup-m3-ipc.yaml     | 13 +++++++++++++
> >  1 file changed, 13 insertions(+)
> > 
> > diff --git a/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml b/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml
> > index d855c01ce61c..7f4a75c5fcaa 100644
> > --- a/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml
> > +++ b/Documentation/devicetree/bindings/soc/ti/wkup-m3-ipc.yaml
> > @@ -24,6 +24,14 @@ description: |+
> >    A wkup_m3_ipc device node is used to represent the IPC registers within an
> >    SoC.
> >  
> > +  Support for VTT Toggle
> > +  ==================================
> > +  On some boards like the AM335x EVM-SK and the AM437x GP EVM, a GPIO pin is
> > +  connected to the enable pin on the DDR VTT regulator. This allows the
> > +  regulator to be disabled upon suspend and enabled upon resume. Please note
> > +  that the GPIO pin must be part of the GPIO0 module as only this GPIO module
> > +  is in the wakeup power domain.
> > +
> >  properties:
> >    compatible:
> >      enum:
> > @@ -51,6 +59,10 @@ properties:
> >        mbox_wkupm3 child node.
> >      maxItems: 1
> >  
> > +  ti,vtt-gpio-pin:
> > +    $ref: /schemas/types.yaml#/definitions/uint32
> > +    description: GPIO pin connected to enable pin on VTT regulator
> 
> Looking at the driver, can't you add 'maximum: 31' here? If so, I can 
> add it when applying.

Yes, good idea. I would appreciate it if that was added when applying.

Thank you,
Drew