MIPI DSI LCD display of i.mx8mq

[jamesko]

Hi,

I am trying to use jdi-lt070me05000(1200x1920 mipi dsi display) on i.mx8mq custom board.

I saw HDMI working fine with DCSS, but now I tried to enable the LCD mentioned above with DCSS(mipi dsi)

Referencing the "fsl-imx8mq-evk-dcss-rm67191.dts" file.

But here I am getting the error as below.

==========================================================================================

[    2.178352] clk: failed to reparent disp_rtrm_pre_div to video_pll1_out: -22

[    2.188997] [drm] Initialized

[    2.197910] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013).

[    2.204607] [drm] No driver support for vblank timestamp query.

[    2.210660] imx-drm display-subsystem: bound imx-dcss-crtc.0 (ops dcss_crtc_ops)

[    2.218218] nwl_dsi-imx mipi_dsi@30A00000: Using DCSS as input source

[    2.224976] 30a00000.mipi_dsi_bridge.0 supply power not found, using dummy regulator

[    2.232886] nwl-mipi-dsi 30a00000.mipi_dsi_bridge: [drm:nwl_dsi_host_attach] lanes=4, format=0x0 flags=0x401

[    2.242789] imx-drm display-subsystem: bound mipi_dsi@30A00000 (ops imx_nwl_dsi_component_ops)

[    2.256144] [drm] OPIPE_CFG: gamut = 1, nl = 1, pr = 1, pix_format = 875713089

[    2.883353] Console: switching to colour frame buffer device 150x120

[    2.945546] imx-drm display-subsystem: fb0:  frame buffer device

==========================================================================================

But, after that, all other prints will look correct, but the LCD will show nothing.

Clock and power sequences are displayed as expected.

fbset command outputs as blow.

Last login: Wed Apr  1 09:01:18 UTC 2020 on tty7

root@myd-imx8mq:~# fbset

mode "1200x1920"

    geometry 1200 1920 1200 1920 32

    timings 0 0 0 0 0 0 0

    accel true

    rgba 8/16,8/8,8/0,0/0

endmode

root@myd-imx8mq:~#

Please check and provide the correct guide.

Thanks in advance,

Regards,

Jamesko

[igorpadykov]

Hi Jamesko

one can try with i.MX8MQ EVK and Demo Images from link

i.MX Software and Development Tools | NXP 

Please verify for correct change the DTB files on Linux:

setenv fdt_file...

saveenv..

Complete procedure is described in Linux Guide from Linux documentation

package on above link:

Linux 5.4.3_1.0.0 Documentation

https://community.nxp.com/docs/DOC-341598 

Best regards
igor
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[jamesko]

Hi igorpadykov

Thank you for answering first.

A content below the guide are already familiar with and check in several times, and was a modification.

setenv fdt_file fsl-imx8mq-evk-dcss-lt070me05000.dtb

saveenv

reset

It was exactly sure.

I am trying to attach a modified dts file.

Where can I attach it?

Thank you.

Best Regards,

Jamesko

[igorpadykov]

Hi Jamesko

what is the reason for modifications of dts file,

one can try with default, follow sect.4. Changing DTS files

on Linux:  "MIPI-DSI-OLED display"

i.MX 8MQ EVK Display Selection Guide 

Best regards
igor

[jamesko]

Hi igorpadykov

The LCD model is different and the manufacturer is different, so we decided to correct it.

Currently supported LCD model : Raydium  RM67191, resolution 1080x1920

LCD model to use : JDI  LT070ME05000, resolution 1200x1920

Thank you.

Best Regards,

Jamesko

[igorpadykov]

for new lcd its specific initialization (based on its datasheet) should be added in driver source

cmd_set_entry manufacturer_cmd_set[], struct drm_display_mode default_mode, rad_panel_enable()

panel-raydium-rm67191.c\panel\drm\gpu\drivers - linux-imx - i.MX Linux kernel 

Best regards
igor

[jamesko]

Hi igorpadykov,

I used the driver in the kernel.

panel-jdi-lt070me05000.c\panel\drm\gpu\drivers-linux-imx-i.MX linux kernel

Are there any problems with this driver?

Thank you.

Beat regards,

Jamesko

[igorpadykov]

Hi Jamesko

>Are there any problems with this driver?

probably not if you also correctly configured .dts file.

Best regards
igor