Re: [PATCH 2/2] phy: qcom-mipi-csi2: Add a CSI2 MIPI D-PHY driver
From: Konrad Dybcio <hidden>
Date: 2025-07-15 09:33:06
Also in:
linux-arm-msm, linux-media, linux-phy, lkml
On 7/15/25 11:20 AM, Vladimir Zapolskiy wrote:
On 7/15/25 12:01, Konrad Dybcio wrote:quoted
On 7/15/25 8:35 AM, Vladimir Zapolskiy wrote:quoted
On 7/15/25 03:13, Bryan O'Donoghue wrote:quoted
On 14/07/2025 16:30, Vladimir Zapolskiy wrote:quoted
quoted
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.quoted
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)It's not about the driver specifics, my comment is about a proper hardware description in dts notation, please see the device tree node names.
I'm a little lost on what you're trying to argue for.. I could make out: 1. "the phy should be a multimedia device" 2. "There is no ports at all, which makes the device tree node unusable, since you can not provide a way to connect any sensors to the phy." I don't really understand #1.. maybe that could be the case if the PHY has a multitude of tunables (which I don't know if it does, but wouldn't be exactly surprised if it did) that may be usecase/pipeline-specific As for #2, I do think it makes sense to connect the sensors to the PHY, as that's a representation of electrical signals travelling from the producer to the consumer (plus the data passed in e.g. data-lanes is directly related to the PHY and necessarily consumed by its driver) Konrad