Re: [PATCH 2/2] phy: qcom-mipi-csi2: Add a CSI2 MIPI D-PHY driver

From: Bryan O'Donoghue
Date: Tue Jul 22 2025 - 05:08:28 EST


On 22/07/2025 09:32, Neil Armstrong wrote:
The whole key point here is the combo mode, as I understood the combo mode feature
makes the PHY lanes available as 2 separate streams, like if you got 2 "controllers"
attached to the same PHY. So in fact, the PHY should have a single node, but 2 PHY
interfaces in combo mode.

This makes all this controller/phy model very complex to handle and add a lot of
logic in the camss side. Moving the "csiphy" as an independent media device that
can declare up to 2 endpoints in combo mode makes things much simpler, and allows
us to attach each "csiphy" stream to any "controller" side of camss.

I think there should be a generic extension to PHY/linux-media to support that instead of something Qualcomm specific.

The first task is qcom/CAMSS specific which is separate the CSIPHYs out from the CAMSS block - done in this series and do so in a way that doesn't break the existing ABI - done in the context of adding Hamoa/x1e.

The second step should be to extend the existing linux-media and PHY API to support multiple sensors on the same CSIPHY in a generic way.

If you want to ship me some hardware, I'll help.

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bod