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

[Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>]

On 7/15/25 8:35 AM, Vladimir Zapolskiy wrote:
> On 7/15/25 03:13, Bryan O'Donoghue wrote:
>> On 14/07/2025 16:30, Vladimir Zapolskiy wrote:
>>>>
>>>> I think that is genuinely something we should handle in camss-csid.c
>>>> maybe with some meta-data inside of the ports/endpoints..
>>>>
>>>
>>> This is a CSIPHY property, a CSIPHY hardware configuration and a wiring
>>> of sensors to a CSIPHY. Where is the relation to CSID here? There is no.
>>
>> All the PHY really needs to know is the # of lanes in aggregate, which
>> physical lanes to map to which logical lanes and the pixel clock.
>>
>> We should add additional support to the Kernel's D-PHY API parameters
>> mechanism to support that physical-to-logical mapping but, that's not
>> required for this series or for any currently know upstream user of CAMSS.
>>
>>> Please share at least a device tree node description, which supports
>>> a connection of two sensors to a single CSIPHY, like it shall be done
>>> expectedly.
>> &camss {
>>       port@0 {
>>           csiphy0_lanes01_ep: endpoint0 {
>>               data-lanes = <0 1>;
>>               remote-endpoint = <&sensor0_ep>;
>>           };
>>
>>           csiphy0_lanes23_ep: endpoint0 {
>>               data-lanes = <2 3>;
>>               remote-endpoint = <&sensor1_ep>;
>>           };
>>        };
>> };
> 
> Don't you understand that this is broken?.. That's no good.
> 
> Please listen and reread the messages given to you above, your proposed
> "solution" does not support by design a valid hardware setup of two
> sensors connected to the same CSIPHY.
> 
> I would propose to stop force pushing an uncorrectable dt scheme, it
> makes no sense.

If all you're asking for is an ability to grab an of_graph reference
from the camss (v4l2) driver, you can simply do something along the
lines of of_graph_get_remote_port(phy->dev->of_node)

Konrad