[PATCH 3/4] dt-bindings: pinctrl-zynqmp: Add output-enable configuration

[Potthuri, Sai Krishna]

Hi Conor,

> -----Original Message-----
> From: Conor Dooley <conor at kernel.org>
> Sent: Tuesday, July 18, 2023 9:20 PM
> To: Potthuri, Sai Krishna <sai.krishna.potthuri at amd.com>
> Cc: Linus Walleij <linus.walleij at linaro.org>; Simek, Michal
> <michal.simek at amd.com>; Rob Herring <robh+dt at kernel.org>; Krzysztof
> Kozlowski <krzysztof.kozlowski+dt at linaro.org>; Conor Dooley
> <conor+dt at kernel.org>; Mathieu Poirier <mathieu.poirier at linaro.org>; Shah,
> Tanmay <tanmay.shah at amd.com>; Levinsky, Ben <ben.levinsky at amd.com>;
> Marek Vasut <marex at denx.de>; Roman Gushchin <roman.gushchin at linux.dev>;
> Arnd Bergmann <arnd at arndb.de>; linux-arm-kernel at lists.infradead.org; linux-
> kernel at vger.kernel.org; linux-gpio at vger.kernel.org; devicetree at vger.kernel.org;
> saikrishna12468 at gmail.com; git (AMD-Xilinx) <git at amd.com>
> Subject: Re: [PATCH 3/4] dt-bindings: pinctrl-zynqmp: Add output-enable
> configuration
> 
> On Mon, Jul 17, 2023 at 03:03:46PM +0530, Sai Krishna Potthuri wrote:
> > Add 'output-enable' configuration parameter to the properties list.
> >
> > Using these pinctrl properties observed hang issues with older Xilinx
> > ZynqMP Platform Management Firmware, hence reverted the patch previously.
> > Commit ff8356060e3a5e126abb ("Revert "dt-bindings: pinctrl-zynqmp: Add
> > output-enable configuration"").
> 
> And what has changed since then that makes it okay to add?
> Is the old firmware not still in the wild?
This time when Linux firmware driver get the request for TRISTATE configuration
from pinctrl driver, it checks if that configuration is supported by the Xilinx ZynqMP
Platform Management firmware. If yes, then calls will be made otherwise it returns error.

Regards
Sai Krishna
> 
> Thanks,
> Conor.
> 
> >
> > Signed-off-by: Sai Krishna Potthuri <sai.krishna.potthuri at amd.com>
> > ---
> >  .../devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml      | 4 ++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git
> > a/Documentation/devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml
> > b/Documentation/devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml
> > index 2722dc7bb03d..1e2b9b627b12 100644
> > ---
> > a/Documentation/devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.yaml
> > +++ b/Documentation/devicetree/bindings/pinctrl/xlnx,zynqmp-pinctrl.ya
> > +++ ml
> > @@ -274,6 +274,10 @@ patternProperties:
> >            slew-rate:
> >              enum: [0, 1]
> >
> > +          output-enable:
> > +            description:
> > +              This will internally disable the tri-state for MIO pins.
> > +
> >            drive-strength:
> >              description:
> >                Selects the drive strength for MIO pins, in mA.
> > --
> > 2.25.1
> >