Does IMX8MM MIPI DSI support bus format

[rajvikamdar]

Spoiler

Hi Team

I am getting error on LCD interface over MIPI-DSI, on IMX8MM. We are interfacing ST7796s on the processor and it is giving error of unsupported bus format.

The bus format that the LCD supports is MEDIA_BUS_FMT_RGB666_1X24_CPADHI, which I figured out from the function imx_sec_dsim_encoder_helper_atomic_check() -> bus_format = adjusted_mode->private_flags & 0xffff.

[ 8.557632] ***** RK: 124 imx_sec_dsim_encoder_helper_atomic_check ******
[ 8.557637] $$$$ bus_format: 4117, num_bus_formats = 1 $$$$
[ 8.557637]
[ 8.557639] ***** RK: 128 imx_sec_dsim_encoder_helper_atomic_check ******
[ 8.557642] ****** RK *******
[ 8.557643]
[ 8.557643]
[ 8.557643] RK: pix_clk: 13860
[ 8.557644]
[ 8.557644]
[ 8.557644] RK: bit_clk: 332640
[ 8.557773] ***** RK: 146 imx_sec_dsim_encoder_helper_atomic_check ******
[ 8.557774] ***** RK: 152 imx_sec_dsim_encoder_helper_atomic_check ******
[ 8.557776] ***** RK: 167 imx_sec_dsim_encoder_helper_atomic_check ******
[ 8.557791] imx-lcdif-crtc imx-lcdif-crtc.0: unsupported bus format: 0x1015
[ OK ] Started DNS forwarder and DHCP server.
[ 8.663423] ***** RK: 124 imx_sec_dsim_encoder_helper_atomic_check ******
[ 8.663428] $$$$ bus_format: 4117, num_bus_formats = 1 $$$$
[ 8.663428]
[ 8.663430] ***** RK: 128 imx_sec_dsim_encoder_helper_atomic_check ******
[ 8.663432] ****** RK *******
[ 8.663433]
[ 8.663433]
[ 8.663433] RK: pix_clk: 13860
[ 8.663434]
[ 8.663434]
[ 8.663434] RK: bit_clk: 332640
[ 8.663565] ***** RK: 146 imx_sec_dsim_encoder_helper_atomic_check ******
[ 8.663567] ***** RK: 152 imx_sec_dsim_encoder_helper_atomic_check ******
[ 8.663568] ***** RK: 167 imx_sec_dsim_encoder_helper_atomic_check ******
[ 8.663583] imx-lcdif-crtc imx-lcdif-crtc.0: unsupported bus format: 0x1015
[ OK ] Started Weston Wayland Compositor (on tty7).
[ OK ] Created slice User Slice of UID 0.
Starting User Runtime Directory /run/user/0...
[ OK ] Started User Runtime Directory /run/user/0.
Starting User Manager for UID 0...
[ OK ] Started User Manager for UID 0.
[ OK ] Started Session c1 of user root.
[ 9.388059] ******* RK *******
[ 9.398811]
[ 9.398811] Bus Format return: 0
[ OK ] Started Variscite Bluetooth setup service.
[ OK ] Reached target Multi-User System.
Starting Update UTMP about System Runlevel Changes...
[ OK ] Started Update UTMP about System Runlevel Changes.
[ 9.516218] ***** RK: 124 imx_sec_dsim_encoder_helper_atomic_check ******
[ 9.527050] $$$$ bus_format: 4117, num_bus_formats = 1 $$$$
[ 9.527050]
[ 9.540297] ***** RK: 128 imx_sec_dsim_encoder_helper_atomic_check ******
[ 9.550757] ****** RK *******
[ 9.561425]
[ 9.561425]
[ 9.561425] RK: pix_clk: 13860
[ 9.572274]
[ 9.572274]
[ 9.572274] RK: bit_clk: 332640
[ 9.582585] ***** RK: 146 imx_sec_dsim_encoder_helper_atomic_check ******
[ 9.592269] ***** RK: 152 imx_sec_dsim_encoder_helper_atomic_check ******
[ 9.604262] ***** RK: 167 imx_sec_dsim_encoder_helper_atomic_check ******
[ 9.611263] imx-lcdif-crtc imx-lcdif-crtc.0: unsupported bus format: 0x1015

How can I check the bus format supported by the processor and LCD module?

[bryan_l_courtne]

Hi,

Was there a solution to the error message "No hblank data for mode 320x480 with 1 lanes"?

We are getting similar error "No hblank data for mode 240x320 with 1 lanes"

THanks

Bryan

[rajvikamdar]

Hi @joanxie 

We are able to resolve the issue, we had to enable the flag MIPI_DSI_CLOCK_NON_CONTINUOUS and use the RGB mode 565 and many more configuration changes. Find attached code directory.

[rajvikamdar]

Hi @joanxie 

Does IMX8MM processor not support the bus format - 0x1015 Why are we getting this error? We need response on this ASAP. Its the issue of processor i think.

When I boot with RGB666, I get the unsupported bus format. But when I boot with RGB666_PACKED, the processor hangs and does not boot up completely. Can you help us please?

[rajvikamdar]

Can someone help me on this? Its a bit urgent..

[joanxie]

what format do you use? rgb666? as I known imx8mm has "imx-lcdif-crtc imx-lcdif-crtc.0: unsupported bus format" message, even you don't connect any displya, what's your output from the lcd? nothing or wrong color?  and what bsp version do you use?

[rajvikamdar]

Hi @joanxie 

Thanks for responding. Yes, our LCD supports RGB666 format. But our LCD is connected over MIPI-DSI interface of the SOM module. So we will have to use the LCDIF CRTC configurations?

We are not getting any display on the LCD screen. We are using BSP: zeus-fsl-5.4.3-mx8mm-v1.1 based on L5.4.3-1.0.0.

Can you please help us urgently on this. We are pretty much stucked.

[joanxie]

pls refer to the document as below to check if you set the clock correctly

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/Setting-i-MX8M-Mini-and-Nano-MIPI-DPHY-C...

[rajvikamdar]

Yes, we have set the clock according to the attached document. 

Should we get something on the display even if we have error of unsupported bus format?

[joanxie]

did you add your own panel driver? you can refer to the rm6719, which supports MEDIA_BUS_FMT_RGB666_1x18

https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/gpu/drm/panel/panel-raydium-rm6719...

you also can refer to the topic as below:

https://community.nxp.com/t5/i-MX-Processors/how-to-add-a-new-panel-with-imx8mm-evk-I-got-some-probl...

[rajvikamdar]

Yes, we have implemented according to the same configurations as attached - rm6719, but we are getting the same error of unsupported bus format.

Please find attached updated code. Could you please help us more? Does IMX8MM not support CPADHI configuration?

[rajvikamdar]

Hi @joanxie 

I resolved the issue of unsupported bus format

we used reference of raydium panel-rm67191 with RGB666_PACKED format settings and modified sitronix panel driver. Find attached driver file. (panel-str-str7796.c)

But now we are facing the following issue "No hblank data for mode 320x480 with 1 lanes", the  LCD supports single lane DSI channel. Further  debugging seems that the API: static const struct dsim_hblank_par *sec_mipi_dsim_get_hblank_par () does not have 1 dsi lane support added in the code.

We are getting /dev/fb0 as framebuffer, but we are not yet getting any output on the screen.

We are trying to do the following:

1. cat /dev/urandom > /dev/fb0

2. gst-launch-1.0 -v videotestsrc ! video/x-raw,width=480,height=320 ! autovideosink

output: FIXME default gstutils.c:3980:gst_pad_create_stream_id_internal:<videotestsrc0:src> Cred
/GstPipeline:pipeline0/GstVideoTestSrc:videotestsrc0.GstPad:src: caps = video/x-raw, format=(string)I420, width=(int)480, height=(int)320, fre
/GstPipeline:pipeline0/GstCapsFilter:capsfilter0.GstPad:src: caps = video/x-raw, format=(string)I420, width=(int)480, height=(int)320, framere
/GstPipeline:pipeline0/GstAutoVideoSink:autovideosink0.GstGhostPad:sink.GstProxyPad:proxypad0: caps = video/x-raw, format=(string)I420, widthe
/GstPipeline:pipeline0/GstAutoVideoSink:autovideosink0/GstWaylandSink:autovideosink0-actual-sink-wayland.GstPad:sink: caps = video/x-raw, fore
/GstPipeline:pipeline0/GstAutoVideoSink:autovideosink0.GstGhostPad:sink: caps = video/x-raw, format=(string)I420, width=(int)480, height=(inte
/GstPipeline:pipeline0/GstCapsFilter:capsfilter0.GstPad:sink: caps = video/x-raw, format=(string)I420, width=(int)480, height=(int)320, framee
0:00:00.057853625 528 0x206b00f0 WARN waylandsink wlwindow.c:330:gst_wl_window_new_internal: init surface_state fail, fallb)

Have attached Log file - Logs.txt , DTS file: imx8mm-var-dart.dts, driver file: panel-str-str7796.c

Can NXP team help us on this.