Re: [PATCH 12/14] media: sunxi: Add support for the A83T MIPI CSI-2 controller

Paul Kocialkowski
2020-11-04T10:37:43Z

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Hi,

On Mon 26 Oct 20, 18:00, Maxime Ripard wrote:
> On Fri, Oct 23, 2020 at 07:45:44PM +0200, Paul Kocialkowski wrote:
> > The A83T supports MIPI CSI-2 with a composite controller, covering both the
> > protocol logic and the D-PHY implementation. This controller seems to be found
> > on the A83T only and probably was abandonned since.
> >
> > This implementation splits the protocol and D-PHY registers and uses the PHY
> > framework internally. The D-PHY is not registered as a standalone PHY driver
> > since it cannot be used with any other controller.
> >
> > There are a few notable points about the controller:
> > - The initialisation sequence involes writing specific magic init values that
> > do not seem to make any particular sense given the concerned register fields.
> > - Interrupts appear to be hitting regardless of the interrupt mask registers,
> > which can cause a serious flood when transmission errors occur.
>
> Ah, so it's a separate driver too.
>
> > This work is based on the first version of the driver submitted by
> > Kévin L'hôpital, which was adapted to mainline from the Allwinner BSP.
> > This version integrates MIPI CSI-2 support as a standalone V4L2 subdev
> > instead of merging it in the sun6i-csi driver.
> >
> > It was tested on a Banana Pi M3 board with an OV8865 sensor in a 4-lane
> > configuration.
>
> Co-developped-by and SoB from Kevin?

Not really. I wrote this driver from scratch and even significantly reworked
the register descriptions to the point that I don't think it makes sense to
consider that he's an author. For parts that can be considered a derivative
work, copyright attribution was given in the header.

Cheers,

Paul

> Looking at the driver, the same comments from the v3s apply there
>
> Maxime

--
Paul Kocialkowski, Bootlin
Embedded Linux and kernel engineering
https://bootlin.com

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