Re: [PATCH v5 04/13] media: atmel: atmel-isc: implement media controller

[Jacopo Mondi <jacopo@jmondi.org>]

Hi Eugen,

On Thu, Feb 17, 2022 at 02:59:19PM +0000, Eugen.Hristev@microchip.com wrote:
> On 2/17/22 3:56 PM, Eugen Hristev wrote:
> > Implement the support for media-controller.
> > This means that the capabilities of the driver have changed and now
> > it also advertises the IO_MC .
> > The driver will register it's media device, and add the video entity to this
> > media device. The subdevices are registered to the same media device.
> > The ISC will have a base entity which is auto-detected as atmel_isc_base.
> > It will also register a subdevice that allows cropping of the incoming frame
> > to the maximum frame size supported by the ISC.
> > The ISC will create a link between the subdevice that is asynchronously
> > registered and the atmel_isc_scaler entity.
> > Then, the atmel_isc_scaler and atmel_isc_base are connected through another
> > link.
> >
> > Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> > ---
>
>
> Hello Jacopo,
>
> I will add to this patch a little update about how the scaler is seen
> now by the media-ctl :
>
> for imx219 sensor, which generates 3280x2464:
>
>
> - entity 1: atmel_isc_scaler (2 pads, 2 links)
>              type V4L2 subdev subtype Unknown flags 0
>              device node name /dev/v4l-subdev0
>          pad0: Sink
>                  [fmt:SRGGB10_1X10/3280x2464 field:none colorspace:srgb
>                   crop.bounds:(0,0)/3280x2464
>                   crop:(0,0)/3264x2464]
>                  <- "csi2dc":1 [ENABLED,IMMUTABLE]
>          pad1: Source
>                  [fmt:SRGGB10_1X10/3264x2464 field:none colorspace:srgb]
>                  -> "atmel_isc_common":0 [ENABLED,IMMUTABLE]
>
>
> The source pad of the scaler looks good now.
>
> For the imx274 which I am using (and it generates 3840x2160 ):
>
> - entity 1: atmel_isc_scaler (2 pads, 2 links)
>              type V4L2 subdev subtype Unknown flags 0
>              device node name /dev/v4l-subdev0
>          pad0: Sink
>                  [fmt:SRGGB10_1X10/3840x2160 field:none colorspace:srgb
>                   crop.bounds:(0,0)/3840x2160
>                   crop:(0,0)/3264x2160]
>                  <- "csi2dc":1 [ENABLED,IMMUTABLE]
>          pad1: Source
>                  [fmt:SRGGB10_1X10/3264x2160 field:none colorspace:srgb]
>                  -> "atmel_isc_common":0 [ENABLED,IMMUTABLE]
>
> So in both cases, each line is cropped down to 3264 as the maximum width.
>
> If we select a lower frame size, the scaler will automatically update
> the source pad to reflect this, e.g.:
>
>
> - entity 1: atmel_isc_scaler (2 pads, 2 links)
>              type V4L2 subdev subtype Unknown flags 0
>              device node name /dev/v4l-subdev0
>          pad0: Sink
>                  [fmt:SRGGB10_1X10/1920x1080 field:none colorspace:srgb
>                   crop.bounds:(0,0)/1920x1080
>                   crop:(0,0)/1920x1080]
>                  <- "csi2dc":1 [ENABLED,IMMUTABLE]
>          pad1: Source
>                  [fmt:SRGGB10_1X10/1920x1080 field:none colorspace:srgb]
>                  -> "atmel_isc_common":0 [ENABLED,IMMUTABLE]
>
>
> does it look good now ?

great! I think it now works as intended, thanks!

I only have one question. BOUND target is the larger rectangle that
contains all crop rectangles. As your max crop is limited to 3264x2160
I wonder if BOUND should be limited by the same size. Does
v4l2-compliance check for this.

Otherwise it looks good!

Thanks
  j

>
> Thanks for checking this out !
> Eugen