Re: [RFC V2 0/5] arm64: dts: imx8mm: Enable CSI and OV5640 Camera

[Adam Ford]

On Sun, Oct 24, 2021 at 7:16 AM Fabio Estevam <festevam@xxxxxxxxx> wrote:
>
> Hi Adam,
>
> [Adding Frieder on Cc]
>
> On Sat, Oct 23, 2021 at 5:35 PM Adam Ford <aford173@xxxxxxxxx> wrote:
> >
> > The imx8mm appears to have both a CSI bridge and mipi-csi-2 drivers.  With
> > those enabled, both the imx8mm-evk and imx8mm-beacon boards should be able
> > use an OV5640 camera.
> >
> > The mipi-csi2 driver sets the clock frequency to 333MHz, so the clock parent
> > of the CSI1 must be reparented to a faster clock.  On the custom NXP kernel,
> > they use IMX8MM_SYS_PLL2_1000M, so that is done in the device tree to match.
> >
> > With the CSI and mipi_csi2 drivers pointing to an OV5640 camera, the media
> > pipeline can be configured with the following:
> >
> >     media-ctl --links "'ov5640 1-003c':0->'imx7-mipi-csis.0':0[1]"
> >
> > The camera and various nodes in the pipeline can be configured for UYVY:
> >     media-ctl -v -V "'ov5640 1-003c':0 [fmt:UYVY8_1X16/640x480 field:none]"
> >     media-ctl -v -V "'csi':0 [fmt:UYVY8_1X16/640x480 field:none]"
> >
> > With that, the media pipeline looks like:
> >
> >
> > Media controller API version 5.15.0
> >
> > Media device information
> > ------------------------
> > driver          imx7-csi
> > model           imx-media
> > serial
> > bus info        platform:32e20000.csi
> > hw revision     0x0
> > driver version  5.15.0
> >
> > Device topology
> > - entity 1: csi (2 pads, 2 links)
> >             type V4L2 subdev subtype Unknown flags 0
> >             device node name /dev/v4l-subdev0
> >         pad0: Sink
> >                 [fmt:UYVY8_1X16/640x480 field:none colorspace:srgb xfer:srgb ycbcr:601 quantization:lim-range]
> >                 <- "imx7-mipi-csis.0":1 [ENABLED,IMMUTABLE]
> >         pad1: Source
> >                 [fmt:UYVY8_1X16/640x480 field:none colorspace:srgb xfer:srgb ycbcr:601 quantization:lim-range]
> >                 -> "csi capture":0 [ENABLED,IMMUTABLE]
> >
> > - entity 4: csi capture (1 pad, 1 link)
> >             type Node subtype V4L flags 0
> >             device node name /dev/video0
> >         pad0: Sink
> >                 <- "csi":1 [ENABLED,IMMUTABLE]
> >
> > - entity 10: imx7-mipi-csis.0 (2 pads, 2 links)
> >              type V4L2 subdev subtype Unknown flags 0
> >              device node name /dev/v4l-subdev1
> >         pad0: Sink
> >                 [fmt:UYVY8_1X16/640x480 field:none colorspace:smpte170m xfer:709 ycbcr:601 quantization:lim-range]
> >                 <- "ov5640 1-003c":0 [ENABLED]
> >         pad1: Source
> >                 [fmt:UYVY8_1X16/640x480 field:none colorspace:smpte170m xfer:709 ycbcr:601 quantization:lim-range]
> >                 -> "csi":0 [ENABLED,IMMUTABLE]
> >
> > - entity 15: ov5640 1-003c (1 pad, 1 link)
> >              type V4L2 subdev subtype Sensor flags 0
> >              device node name /dev/v4l-subdev2
> >         pad0: Source
> >                 [fmt:UYVY8_1X16/640x480@1/30 field:none colorspace:srgb xfer:srgb ycbcr:601 quantization:full-range]
> >                 -> "imx7-mipi-csis.0":0 [ENABLED]
> >
> > When configured, gstreamer can be used to capture 1 frame and store it to a file.
> >
> > gst-launch-1.0 -v v4l2src num-buffers=1 ! video/x-raw,format=UYVY,width=640,height=480,framerate=60/1 ! filesink location=test
> >
> > Unfortunately, the video capture never appears to happen.  No errors occur, not
> > interrupts are recorded and no errors are recorded.
> >
> > gst-launch-1.0 -v v4l2src num-buffers=1 ! video/x-raw,format=UYVY,width=640,height=480,framerate=60/1 ! filesink location=test
> > Setting pipeline to PAUSED ...
> > Pipeline is live and does not need PREROLL ...
> > Pipeline is PREROLLED ...
> > Setting pipeline to [  114.819632] v4l2_get_link_freq: Link frequency estimated using pixel rate: result might be inaccurate
> > PLAYING ...
> > New clock: GstSystem[  114.829203] v4l2_get_link_freq: Consider implementing support for V4L2_CID_LINK_FREQ in the transmitter driver
> > Clock
> > /GstPipeline:pipeline0/GstV4l2Src:v4l2src0.GstPad:src: caps = video/x-raw, format=(string)UYVY, width=(int)640, height=(int)480, framerate=(fraction)60/1, interlace-mode=(string)progressive, colorimetry=(string)bt709
> > /GstPipeline:pipeline0/GstCapsFilter:capsfilter0.GstPad:src: caps = video/x-raw, format=(string)UYVY, width=(int)640, height=(int)480, framerate=(fraction)60/1, interlace-mode=(string)progressive, colorimetry=(string)bt709
> > /GstPipeline:pipeline0/GstFileSink:filesink0.GstPad:sink: caps = video/x-raw, format=(string)UYVY, width=(int)640, height=(int)480, framerate=(fraction)60/1, interlace-mode=(string)progressive, colorimetry=(string)bt709
> > /GstPipeline:pipeline0/GstCapsFilter:capsfilter0.GstPad:sink: caps = video/x-raw, format=(string)UYVY, width=(int)640, height=(int)480, framerate=(fraction)60/1, interlace-mode=(string)progressive, colorimetry=(string)bt709
> >
> >
> > If anyone has any insight as to what might be wrong, I'd like feedback.
> > I posted a device tree that I beleive goes with the newer imx8mm-evk, but
> > I do not have this hardware, so I cannot test it.
>
> It seems that Frieder on Cc managed to get camera capture to work on
> i.MX8MM here:
> https://git.kontron-electronics.de/sw/misc/linux/-/commits/v5.10-mx8mm-csi
>
> Hopefully, this can help to figure out what is missing in mainline to
> get camera capture to work on i.MX8M.
>
> I don't have access to an OV5640 camera to connect to the imx8mm-evk
> board to try your series.

Fabio,

Thanks for the heads up on that repo.  I was able to use that repo and
get still images to capture on an OV5640, but I noticed a fair amount
of differences between that repo and what's found in linux-next.

Laurent,

I haven't exhausted the patch differences, but I found at least a few
that appear to be missiing upstream, and I am curious to know if/what
your opinion is on whether or not they're needed, since the patches on
Frieder's repo appear to come from you.
[1] - media: imx: imx7-media-csi: Add i.MX8MM identification
[2] - media: imx: imx7_mipi_csis: Don't set reserved CLK_CTRL field on i.MX8MM
[3] - media: imx: imx7_mipi_csis: Set dual pixel mode for RAW formats

media: imx: imx7_mipi_csis: Set dual pixel mode for RAW formats

Maybe these don't need to be applied, but they are 'some' of the
differences that I see between this 5.10 branch and linux-next .  I
know there are more, but


[1] - https://git.kontron-electronics.de/sw/misc/linux/-/commit/8ac7ec6db0c260a871038721886dbdb6660ed84c
[2] - https://git.kontron-electronics.de/sw/misc/linux/-/commit/0b5727c8eba8c370f7db5eace0243f78992a4dbb
[3] - https://git.kontron-electronics.de/sw/misc/linux/-/commit/14befa6bc146b10092a6ac5d0ed4d42c87c6cf27

Frieder et al,

Have you (or anyone) tried CSI cameras on anything newer than 5.10?  I
am curious to see if a regression popped in somewhere, but git bisect
will make this difficult since there is a fair amount of variation
between this custom repo and the upstream.

adam
>
> Regards,
>
> Fabio Estevam