Re: [PATCH 1/4] media: imx.rst: Fix the MIPI CSI-2 virtual channel

[Steve Longerbeam <slongerbeam@gmail.com>]

Hi Fabio, thanks for the patch.

On 4/8/20 5:32 AM, Fabio Estevam wrote:
> The current instructions for imx6q-sabresd do not lead to functional
> capture on OV5640 MIPI CSI-2.
>
> The reason for this, as explained by Steve Longerbeam, is that OV5640 by
> default transmits on virtual channel 0, not channel 1 as is given in the
> instructions.
>
> Adapt the instructions to use virtual channel 0 so that a working
> camera setup can be achieved on imx6q-sabresd.
>
> Suggested-by: Steve Longerbeam <slongerbeam@gmail.com>
> Signed-off-by: Fabio Estevam <festevam@gmail.com>
> ---
> Hi Steve,
>
> I don't have access to a imx6q sabrelite with camera, but I think
> it needs fixing as well.
>
>   Documentation/media/v4l-drivers/imx.rst | 23 ++++++++++++-----------
>   1 file changed, 12 insertions(+), 11 deletions(-)
>
> diff --git a/Documentation/media/v4l-drivers/imx.rst b/Documentation/media/v4l-drivers/imx.rst
> index 1246573c1019..7c3afd32e456 100644
> --- a/Documentation/media/v4l-drivers/imx.rst
> +++ b/Documentation/media/v4l-drivers/imx.rst
> @@ -645,25 +645,26 @@ The OV5640 module connects to MIPI connector J5 (sorry I don't have the
>   compatible module part number or URL).
>   
>   The following example configures a direct conversion pipeline to capture
> -from the OV5640, transmitting on MIPI CSI-2 virtual channel 1. $sensorfmt
> -can be any format supported by the OV5640. $sensordim is the frame
> -dimension part of $sensorfmt (minus the mbus pixel code). $outputfmt can
> -be any format supported by the ipu1_ic_prpenc entity at its output pad:
> +from the OV5640, transmitting on MIPI CSI-2 virtual channel 0:

Since this is an Image Converter pipeline, it would be nice to 
demonstrate scaling and color conversion in this example. How about 
changing the format at IC output to be ARGB8888_1X32/800x600. So change 
the explanation of the pipeline above, and:

>   
>   .. code-block:: none
>   
>      # Setup links
>      media-ctl -l "'ov5640 1-003c':0 -> 'imx6-mipi-csi2':0[1]"
> -   media-ctl -l "'imx6-mipi-csi2':2 -> 'ipu1_csi1':0[1]"
> -   media-ctl -l "'ipu1_csi1':1 -> 'ipu1_ic_prp':0[1]"
> +   media-ctl -l "'imx6-mipi-csi2':1 -> 'ipu1_csi0_mux':0[1]"
> +   media-ctl -l "'ipu1_csi0_mux':2 -> 'ipu1_csi0':0[1]"
> +   media-ctl -l "'ipu1_csi0':1 -> 'ipu1_ic_prp':0[1]"
>      media-ctl -l "'ipu1_ic_prp':1 -> 'ipu1_ic_prpenc':0[1]"
>      media-ctl -l "'ipu1_ic_prpenc':1 -> 'ipu1_ic_prpenc capture':0[1]"
>      # Configure pads
> -   media-ctl -V "'ov5640 1-003c':0 [fmt:$sensorfmt field:none]"
> -   media-ctl -V "'imx6-mipi-csi2':2 [fmt:$sensorfmt field:none]"
> -   media-ctl -V "'ipu1_csi1':1 [fmt:AYUV32/$sensordim field:none]"
> -   media-ctl -V "'ipu1_ic_prp':1 [fmt:AYUV32/$sensordim field:none]"
> -   media-ctl -V "'ipu1_ic_prpenc':1 [fmt:$outputfmt field:none]"
> +   media-ctl -V "'ov5640 1-003c':0 [fmt:UYVY2X8/640x480]"
> +   media-ctl -V "'imx6-mipi-csi2':1 [fmt:UYVY2X8/640x480]"
> +   media-ctl -V "'ipu1_csi0_mux':2 [fmt:UYVY2X8/640x480]"
> +   media-ctl -V "'ipu1_csi0':0 [fmt:UYVY2X8/640x480]"

don't need this line (I pulled this from a script that was testing 
crop/compose on sink pad ipu1_csi0:0, but since we're not doing that 
here, you can remove the format setup line for ipu1_csi0:0).

> +   media-ctl -V "'ipu1_csi0':1 [fmt:AYUV32/640x480]"
> +   media-ctl -V "'ipu1_ic_prp':1 [fmt:AYUV32/640x480]"
> +   media-ctl -V "'ipu1_ic_prpenc':0 [fmt:AYUV32/640x480]"

don't need this line.

> +   media-ctl -V "'ipu1_ic_prpenc':1 [fmt:AYUV32/640x480]"

change to:

media-ctl -V "'ipu1_ic_prpenc':1 [fmt:ARGB8888_1X32/800x600]"


>   
>   Streaming can then begin on "ipu1_ic_prpenc capture" node. The v4l2-ctl
>   tool can be used to select any supported YUV or RGB pixelformat on the

"...The v4l2-ctl tool can be used to select any supported RGB pixelformat..."


Steve