AnsweredAssumed Answered

YCC 422 16 bit parallel mode times out.

Question asked by Robert Chapin on Jul 24, 2017
Latest reply on Aug 1, 2017 by igorpadykov

Kernel version: 4.1.15-1.1.0-ga-wandboard:

Board Support package/yocto: yocto pryo and fsl-community bsp.

Processor: IMX6 solo.


We have a FPGA connected to the CSI0 parallel port. The plan is to connect a sensor to the FPGA and output 422 data in parallel mode to the IMX6. To simplify things, we added a test pattern generator in the FPGA that is always running sending raw YCC422 data with no sync codes.


FPGA: I have verified the pin out from FPGA to IMX6 solo and was able to monitor CSIO_MCLK, CSI0_PIXCLK, CSIO_VSYN and CSI0_DATA_EN with an oscilloscope at the input pins of the IMX6.  CSIO_PIXCLK is free running at 8 MHZ.  We are sending 640x480 frames. CSI0_Vsync and CSI0_MClk are 1 clock wide and is the same as the timing diagrams in the IMX6SDLRM spec.

SOFTWARE: I used the ov5640 driver as the skeleton driver for the sensor/FPGA. The probe is successful and the driver is registered and loads just fine. To enable parallel mode, I made most of my mods in mxcv4l2_capture.c.  This is one of many scripts that I have played with to send video to the HDMI port/file capture.  This script (below) works when I enable the test pattern mode in the imx6. 

  • gst-launch-1.0 imxv4l2videosrc device=/dev/video0 fps_n=30 imx-capture-mode=4 ! videoparse format=7 width=640 height=480 framerate=30 ! filesink location=testcapture.bin


I have tried both gated and non gated mode and used smaller sizes to try to get IDMAC events. I always get the same results with the following error message.


ERROR: v4l2 capture: mxc_v4l_dqueue timeout enc_counter 0


Here are my registers at timeout.

In MVC:mxc_v4l_dqueue 614400

ERROR: v4l2 capture: mxc_v4l_dqueue timeout enc_counter 0

## MXC RD IPU_CONF 0x2600000 Vir a0a5e000 = 761

## IMXC RD IPU_INT_CTRL_1 0x260003c Vir a0a5e03c = 80000001

## IMXC RD INT_STAT_3 EOF start 0x2600208 Virt a0a5e208 = 800000

## MXC RD INT_STAT_1 EOF end  0x2600200  a0a5e200 = 800000

## MXC RD IDMAC_CH_BUSY_1 0x2608100 Virt a0a66100 = 800000

## MXC RD CSI0_SENS_CONF 0x02630000 Vir a0a6e000 = 400cb10

## MXC RD CSI0_SENS_FRM_SIZE 0x02630004 Vir a0a6e004 = 1df027f

## MXC RD CSI0_ACT_FRM_SIZE 0x02630008 Vir a0a6e008 = 1df027f

## MXC RD CSI0_OUT_FRM_CTRL 0x0263000c Vir a0a6e00c = 0

## MXC RD IPU_CSI0_TST_CTRL  0x02630010 Vir a0a6e010 = 0

## MXC RD IOMUXC_GPR13 0x020e0034 Vir f42e0034 = 4

## MXC RD IOMUXC_SW_MUX_CTL_PAD_CSIO_PIX 0x020e0094 Vir f42e0094 = 10

## MXC RD IOMUXC_SW_MUX_CTL_PAD_CSIO_HSYNC 0x020e0090 Vir f42e0090 = 10

## MXC RD IOMUXC_SW_MUX_CTL_PAD_CSIO_VSYNC 0x020e0098 Vir  f42e0098 = 10

## MXC RD IOMUXC_SW_MUX_CTL_PAD_CSIO_DATA_EN  0x020e008c Vir f42e008c = 10

## MXC CPMEM WD 1  0x02700000 Vir a0a76000 = 0

## MXC CPMEM WD 2  0x02700004 Vir a0a76004 = 0

## MXC CPMEM WD 3  0x02700008 Vir a0a76008 = 0

## MXC CPMEM WD 4  0x0270000c Vir a0a7600c = e0001800

## MXC CPMEM WD 5  0x02700010 Vir a0a76010 = 77c4f

ERROR: from element /GstPipeline:In MVC:mxc_v4l_ioctl

pipeline0/GstImxV4l2VideoSrc:imxvIn MVC: mxc_v4l_do_ioctl 40045613


NOTES/more questions:

  •      I do not see an IDMAC New frame acknowledge.
  •     On page 2881 in the IMX6SDLRM spec it states


16 bit YUV422


In this mode the CSI receives 2 components per cycle. The CSI is programmed to

accept the data as 16 bit generic data. The captured data will be stored in the memory

through the SMFC. The IDMAC needs to be programmed to store 16bit generic data.

When the data is read back from the memory for further processing in the IPU it will

be read as YUV422 data.


I cannot find anywhere in the spec about how to program the IDMAC to store 16bit generic data.


  •      Is there a way to monitor the SMFC to see if it gets any data?
  •      It appears in order to get parallel data without using embedded sync codes, mxcv4l2_capture.c needs to be modified. Is there an mxcv4l2_capture.c that exists that has all the proper register setting to support the parallel interface sending generic/raw data.