CSI BT656 - need of HSYNC/VSYNC?

[MicMoba]

Hello,

I currently develop a v4l2-subdev driver for an iMX6Q. My device is an anlog video encoder and has a BT656 8bit parallel output.

Pixelclock: 27MHz.

Total pixelcount per line: 864

Number of lines: 625

Video size: 720x576 (PAL)

My device has also HSYNC, VSYNC and DATA_ENABLE output.

The HSYNC and VSYNC outputs can work as SYNC or as VALID signal. I read in the IMX6DQCEC.pdf document  on page 98 that in BT656 mode no sync lines are needed. The sync signals were build internaly out of the embedded sync SAV/EAV.

- What do I need when I use CSI0 in BT656 interlaced mode? HSYNC/VSYNC or HVALID/VVALID or DATA_EN?

- How can I check that the IPU receives correct data? Is there a v4l2-ctl function to write raw data to an file maybe?

I tried the following but without success

v4l2-ctl -d /dev/video0  --stream-mmap --stream-count=100

(http://cache.freescale.com/files/32bit/doc/data_sheet/IMX6DQCEC.pdf )

Thanks

[igorpadykov]

Hi Michael

right, in BT656 mode no sync lines are needed. For software examples one can
check OV5640 driver described in sect.6.1.3 Parallel CSI attached Linux Manual.

and mxc_v4l2_tvin.c unit test:

mxc_v4l2_tvin.c\mxc_v4l2_test\test - imx-test - i.MX Driver Test Application Software 

Best regards
igor
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[MicMoba]

Hi igorpadykov,

thanks for your reply.

My sensor has an output of 864px with 625 lines.

What should I configure in the sensor struct during probe?

sen.pix.width = 864;
sen.pix.height = 625;

or

sen.pix.width = 720;
sen.pix.height = 576;

I tried several combinations but at all of them occurs an error:

imx-ipuv3 2400000.ipu: Unsupported CCIR656 interlaced video mode

only when I set

sen.pix.width = 720;
sen.pix.height = 625;

this error message doesn't come.