[coreboot-gerrit] Change in coreboot[master]: soc/intel/gpio: set default value for RXEVCFG in native mode

[Michael Niewöhner (Code Review)]

Michael Niewöhner has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/41030 )

Change subject: soc/intel/gpio: set default value for RXEVCFG in native mode
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Patch Set 1:
> Patch Set 1:
> > Patch Set 1:
> > > Patch Set 1:
> > >
> > > (1 comment)
> >
> > That's skylake/kabylake PCH BIOS write guide.
> > What I try to say is, GPIO as native mode for output, native mode take full control. But GPIO pin as native mode for input, the following register can still take effect. RXRAW,RXTXEnCfg,DebEn,PreGfRXSel,RXINV,RxPadStSel.
> >
> > So the original of the commit is actual right, bufdis/trig will not be effected by native mode anyway.
>
> I agree with Lance about setting trig for NF. However, I'm not sure about bifdis.
>
> From 3rdparty/fsp/KabylakeFspBinPkg/Include/GpioConfig.h:
>
> "When in native mode setting Direction (except Inversion)..."
> I think this means that for inverted pads the direction should be set. I'm right?
>
> Jonathan also set bufdis settings (GpioDirInOut/GpioDirIn/GpioDirOut) for NF in
> the Tioga Pass:
> https://review.coreboot.org/c/coreboot/+/39453/42/src/mainboard/ocp/tiogapas...

Copied from your/my mail:

However, I see here - "except Inversion".
> I think this means that for inverted pads the direction should be set.
> I'm right?
> What do you think about this?

That's simply misleading because in FSP direction and inversion ("GpioDirInInv") gets set via the same parameter, so they mean inversion is valid all other directions settings are not.