topic Re: MIPI camera through IPU2 in i.MX Processors

MIPI camera through IPU2

richardwoodham — Thu, 05 Oct 2017 14:38:08 GMT

Suppose I have a MIPI camera connected to my i.MX 6 board and I want to route the video signal through IPU2, what changes do I have to make to the device tree?

Do I have to make any other changes? e.g explicitly enable IPU2 clock?

As it stands, with the supplied device tree I can capture image data through IPU1. However, all the changes I have made so far end up with:

Setting pipeline to PLAYING ...
New clock: GstSystemClock
ERROR: v4l2 capture: mxc_v4l_dqueue timeout enc_counter 0
ERROR: from element /GstPipeline:pipeline0/GstImxV4l2VideoSrc:imxv4l2videosrc0: Internal data flow error.
Additional debug info:
../../../../gstreamer-1.8.3/libs/gst/base/gstbasesrc.c(2948): gst_base_src_loop (): /GstPipeline:pipeline0/GstImxV4l2VideoSrc:imxv4l2videosrc0:
streaming task paused, reason error (-5)
Execution ended after 0:00:10.097194002

As if something is not switched on or not configured correctly.

Original Attachment has been moved to: TestMIPI_IPU2.patch.zip

Re: MIPI camera through IPU2

igorpadykov — Thu, 05 Oct 2017 23:49:57 GMT

Hi Richard

for dts IPU numbers one can look at "ipu_id" usage, as in examples on

iMX6DQ MAX9286 MIPI CSI2 720P camera surround view solution for Linux BSP

Best regards
igor
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Re: MIPI camera through IPU2

richardwoodham — Tue, 10 Oct 2017 10:03:36 GMT

I forgot to mention the camera chip I am using. It is OV5640. As it turns out there is a bug in the driver ov5640_mipi.c in the function ov5640_set_virtual_channel which uses csi_id (0 or 1) as the argument. When there are 2 IPUs there are 4 virtual channels and 2 bits in register 0x4814 to be set. If I hard-code the driver to use vc 2 or 3 I get:

which is progress, but not exactly what I wanted. The image is the right size (720p).