Re: [PATCH v5 1/2] dt-bindings: phy: qcom: Add CSI2 C-PHY/DPHY schema

Dmitry Baryshkov
2026-03-29T10:54:52Z

On Fri, Mar 27, 2026 at 11:40:51PM +0000, Bryan O'Donoghue wrote:
> On 27/03/2026 23:23, Dmitry Baryshkov wrote:
> > On Sat, Mar 28, 2026 at 01:12:22AM +0200, Vladimir Zapolskiy wrote:
> > > On 3/28/26 00:29, Bryan O'Donoghue wrote:
> > > > On 27/03/2026 20:51, Dmitry Baryshkov wrote:
> > > > > > That's just not true. If you read the camx source code you can see
> > > > > > split/combo mode 2+1 1+1 data/clock mode requires special programming of the
> > > > > > PHY to support.
> > > > > This needs to be identified from the data-lanes / clock-lanes topology.
> > > > > And once you do that, there would be (probably) no difference in the
> > > > > hardware definition.
> > > > >
> > > > >
> > > > > In other words, I'd also ask to drop this mode from the DT. This
> > > > > infromation can and should be deduced from other, already-defined
> > > > > properties.
> > > >
> > > > It still needs to be communicated to the PHY from the controller,
> > > > however that is not a problem I am trying to solve now.
> > > >
> > > > If I can't get consensus for PHY_QCOM_CSI2_MODE_SPLIT_DPHY then so be it.
> > > >
> > > > I'll aim for DPHY only and we can come back to this topic when someone
> > > > actually tries to enable it.
> > > >
> > >
> > > DPHY may be the only supported phy type in the driver, it does not matter
> > > at this point, however it's totally essential to cover the called by you
> > > 'split mode' right from the beginning in the renewed device tree binding
> > > descriptions of CAMSS IPs to progress further.
> >
> > Okay. How would we describe that there are two sensors connected to the
> > single PHY anyway? How would it be described with the current bindings?
> >
> > --
> > With best wishes
> > Dmitry
>
> Assuming you add endpoints to the PHY i.e. that is what Neil appears to be
> asking for and I personally am _fine_ with that, then it should just be
>
> port@0
> port@1
>
> if port@1 exists, you know you are in split-phy mode.
>
> Its actually straight forward enough, really. To be clear though I can write
> that yaml - the _most_ support I'm willing to put into the PHY code is to
> detect the port@1 and say "nope not supported yet", since like CPHY its not.

SGTM. But let's define the schema for those usecases.

>
> ---
> bod

--
With best wishes
Dmitry