Re: [PATCH RFC] media: i2c: ds90ub960: Enable second i2c interface

From: Tomi Valkeinen
Date: Tue Mar 18 2025 - 10:46:27 EST


Hi,

On 05/03/2025 14:17, Yemike Abhilash Chandra wrote:
The DS90UB960-Q1 includes a second I2C interface for independent control
of the deserializer and remote devices. However, the current driver does
not utilize it, thus restricting users to either CSI TX0 or CSI TX1 on
the primary I2C interface. Enable the second I2C interface, allowing
flexible routing where CSI TX0 can be used on the primary and CSI TX1 on
the secondary, or vice versa by enabling appropriate ports in DT. To
achieve the same only modify the bits relevant to the enabled RX and TX
ports of that interface and during probe and enable_streams call, few
registers were being reset to HW reset state, these operations are not
necessary for functionality and resets the state when secondary I2C
interface is probed, thus drop them.

I'm a bit confused about the description. My recollection is that both CSI TX0 and TX1 can be programmed just fine from the first I2C interface. Is that not so?

Also, even if the driver supports both CSI TXes, at the moment v4l2 framework doesn't work with it, at least in many cases. E.g. if you connect one TX to a CSIRX, the other TX to another CSIRX, and those CSIRXes are independent, have their own media graphs, it's not going to work at all.

So I guess my question is, what's the target here, how did you test this, etc?

Tomi