[PATCH v4 2/2] phy: qcom-mipi-csi2: Add a CSI2 MIPI DPHY driver

[Bryan O'Donoghue]

On 19/03/2026 14:56, Vladimir Zapolskiy wrote:
>> There's no reason to remove that from CAMSS - it would be an ABI break
>> in user-space anyway.
> 
> If technically CAMSS CSIPHY could be excluded from the list of CAMSS media
> subdevices, then for the sake of simplification it should be done for all
> supported platforms in advance, such a change will be independent from this
> particular phy series, and vice versa, this CAMSS only driver change will
> prepare a ground for media-less CAMSS CSIPHY device drivers, hence it shall
> precede this particular CAMSS CSIPHY series.
> 
> For backward compatibility with userspace a noop stub will be good enough,
> it's not an issue at all.

The standalone PHY driver doesn't require removing the CSIPHY media
entity from CAMSS. They serve different purposes and coexist - its 
important to have a NOP from user-space perspective for legacy and 
indeed for new implementations.

How the PHY gets represented in the kernel is of zero interest to 
user-sapce.

That said, stubbing out the media entity is independent work that can 
happen in any order and IMO is a separate debate. Whether or not CSIPHY 
init sequences live inside of a monolithic CAMSS driver or live inside 
off a discrete csiphy driver is not related to the media graph.

Happy to have that debate - and if indicated, carefully apply patches 
separately.

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bod