LOOPBACK of Display Data to Parallel CSI of IMX6Quad

[manojsampathkum]

Hi

 We are using IMx6 Quad based COM for one of our end application with 4.1.15 kernel and yocto poky build, We are doing a loopback of lvds display data to parallel port Using DS90CF384 chip. The chip is used for converting the lvds display data into parallel data.The input to CSI is configured as the 16-bit RGB565 format. It is configured in GATED mode in ipu by default.

Problem which I am facing while trying to capture the frame  using mxc_v4l2_capture.out is

Width = 176 Height = 144[ 646.149254] RGB565
Image size = 50688
pixelformat: RGBP
[ 656.143489] ERROR: v4l2 capture: mxc_v4l_dqueue timeout enc_counter 0
VIDIOC_DQBUF failed.
[ 656.150066] ERROR: v4l2 capture: VIDIOC_QBUF: buffer already queued
VIDIOC_QBUF failed.

I probed and checked the hardware for vsync, hsync,pix_clk and I am getting a proper waveform in the oscilloscope.Device tree entries are also perfect.

Is there anything I need to configure for 16bit in IPU ??

Hoping for a better guidance.

Regards

Manoj.

[manojsampathkum]

Hi Igor,

We have written the driver for 16-bit RGB565. Driver seems correct. But I couldn't able to get a single frame. Same error messages thrown.

" [ 656.143489] ERROR: v4l2 capture: mxc_v4l_dqueue timeout enc_counter 0
VIDIOC_DQBUF failed.
[ 656.150066] ERROR: v4l2 capture: VIDIOC_QBUF: buffer already queued
VIDIOC_QBUF failed."

[igorpadykov]

Hi Manoj

one can check csi timings with oscilloscope using sect.4.11.10.2.2 Gated Clock Mode

i.MX6DQ Datasheet

http://www.nxp.com/docs/en/data-sheet/IMX6DQCEC.pdf

If driver is working, compare timings with working sensor.

Best regards
igor

[igorpadykov]

Hi Manoj

testing procedure is described in sect.6.2.2.3 Unit Test attached Linux Manual,

so appropriate driver should be written for 16-bit RGB565, like ov5640_camera.ko,

seems by default RGB565 is not supported (supported formats are given in sect.6.1.1.2.2)

Best regards
igor
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