v4l2 subdevice with imx6

[vaudoitlaurent]

Hi, 

reading imx linux reference manual, i see that the ov5640 can be used using the internal mxc architecture

(master/slave with mxc_v4l2_capture i guess) or using "standard" v4l2 subdevice.

But on a imx6qp platform, i don't understand how the subdevice implementation works, and how we can get the subdev userspace API working (subdevice should expose a /dev/v4l_subdevX node)

If i understand well, the above driver should call the v4l2_device_register_subdev_nodes function, to have the matching with the subdevices (seems to be done in imx8/mxc-mdeia-dev.c)

but in the 4.19.35 linux-imx kernel, i do not see such call in

mxc_mipi_csi2 or mxc_v4l2_capture.

Is there something i miss?

I would like to have the isl79987 driver working as a subdevice.

Thanks for your answer

Regards

laurent

[vaudoitlaurent]

Hi Igor,

thank you for your quick answer.

this confirm what i was suspecting.

Our idea was to use subdev for setting some cropping directly in the isl79987 instead of at the ipu level, to avoid extra treatment in the imx side.

So i guess that we can create our own v4l2 ioctl to which could be forwarded to the isl driver for such feature

Regards

Laurent

[igorpadykov]

Hi Laurent

I am afraid v4l2 subdevice driver is not used with processors with IPU module

as i.MX6QP. mxc_v4l2_capture can be used with IPU. Also one can look at

description in Linux Manual included in Documentation

Best regards
igor
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