Re: [PATCH v5 7/8] media: i2c: add DS90UB913 driver

Tomi Valkeinen
2022-12-26T19:25:52Z

On 26/12/2022 18:56, Laurent Pinchart wrote:
> Hi Tomi,
>
> On Wed, Dec 14, 2022 at 08:36:47AM +0200, Tomi Valkeinen wrote:
>> On 14/12/2022 08:29, Tomi Valkeinen wrote:
>>
>>>> wondering if the struct device of the DS90UB913 could be passed instead
>>>> of the port, to avoid passing the port throught
>>>> ds90ub9xx_platform_data.
>>>
>>> Interesting thought. That would limit the number of remote i2c busses to
>>> one, though. Not a problem for FPD-Link, but I wonder if that's assuming
>>> too much for the future users. Then again, this is an in-kernel API so
>>> we could extend it later if needed. So I'll try this out and see if I
>>> hit any issues.
>>
>> Right, so the issue with this one would be that it would prevent a
>> single device uses. E.g. a single chip which acts as an ATR (similar to
>> i2c-mux chips), i.e. it contains both the main and the remote i2c busses.
>
> I don't think I understand this, sorry.

What you are suggesting above means that we'd have a separate device for
each port of the ATR. Which is fine in our current case, as the i2c
master busses are behind separate remote devices.

But if you consider a case similar to i2c-mux, where we have a single
chip with the slave bus and, say, 4 master busses. We would probably
have only a single device for that.

Tomi