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Date:   Tue, 12 Apr 2022 14:15:24 -0700
From:   Drew Fustini <dfustini@baylibre.com>
To:     Rob Herring <robh@kernel.org>
Cc:     Krzysztof Kozlowski <krzk+dt@kernel.org>,
        Dave Gerlach <d-gerlach@ti.com>,
        Tony Lindgren <tony@atomide.com>, Nishanth Menon <nm@ti.com>,
        Santosh Shilimkar <ssantosh@kernel.org>,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 1/2] dt-bindings: wkup-m3-ipc: Add vtt toggle gpio pin
 property
Message-ID: <YlXr7M/HXvlXWftR@x1>
References: <20220409211215.2529387-1-dfustini@baylibre.com>
 <20220409211215.2529387-2-dfustini@baylibre.com>
 <YlXY88aJIrcHc5Bc@robh.at.kernel.org>
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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@ti.com>
> > [dfustini: converted to YAML, removed unnecessary "ti,needs-vtt-toggle"]
> > Signed-off-by: Drew Fustini <dfustini@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