Re: [PATCH v8 1/2] dt-bindings: phy: qcom: Add CSI2 C-PHY/DPHY schema

From: Vladimir Zapolskiy

Date: Wed Jul 01 2026 - 19:45:58 EST


On 7/2/26 01:54, Bryan O'Donoghue wrote:
On 02/06/2026 22:59, Vladimir Zapolskiy wrote:
+
+ "#phy-cells":
+ const: 1
+ description:
+ The single cell specifies the PHY operating mode.
#phy-cells should be 0, because the PHY operating mode is well defined
by 'bus-type' property of an endpoint on the sensor side, the opposite
side of CAMSS/CSID as a CSIPHY "consumer" should not dictate the PHY type.

So going through the list I don't believe this is correct.

Be specific what is incorrect.


Inserting bus-type into the PHY layer is borrowing from one domain
linux-media and pushing the concept into PHYs.

It's the other way around, "bus-type" is an endpoint property of media
devices, reference to video-interfaces.yaml to get more details about it.

phy-cells = 1 with CPHY/DPHY specified in the consumer, as was Rob's
suggestion will specify the mode.

This cell is just not needed, and unneeded complexity should not be added.

Then to understand if we are in regular or combo mode, we parse the
ports/endspoints in the PHY node as we've agreed already.


That's correct, and while it's unavoidable to parse endpoint properties,
a phy cell value will not bring any additional information, in the best
case it's useless, or it opens a door to a clash, if different phy types
are occasionally specified twice.

--
Best wishes,
Vladimir