Re: [PATCH v5] Driver for ON Semi AR0521 camera sensor

From: Sakari Ailus
Date: Tue Oct 12 2021 - 16:30:12 EST


Hi Krzysztof,

On Tue, Oct 12, 2021 at 02:24:17PM +0200, Krzysztof Hałasa wrote:
> Jacopo,
>
> > I'll pretend I haven't read this not to be dragged in tangential
> > discussions. My whole point was such a commit message is useless as I
> > assume if you submit a driver for inclusion you have tested it.
>
> Fine, I will remove that very commit comment.
>
> > I think the clock rate should be assigned in DTS and you should verify
> > it falls in the supported clock ranges.
>
> Which driver does that, please?
> clk_set_rate() appears to be used by multiple drivers, I was thinking
> I can use it.
> I can see clock frequencies in DTS, but they usually refer to fixed
> clocks (e.g. crystal-based). The clock I use is IMX6QDL_CLK_CKO, some
> sort of a shared generic clock from inside of the CPU. I don't know if
> I could even set its frequency in DTS.

Please see:

https://hverkuil.home.xs4all.nl/spec/driver-api/camera-sensor.html

Generally camera sensor drivers that set the clock in drivers themselves
are (very) old.

--
Regards,

Sakari Ailus