MIPI-DSI panel support on iMX8M Mini

[prasannakulkarni]

Hi All,

We have made a custom board using iMX8M mini SOC. We need to integrate MIPI-DSI panel on this board.  we have few doubts on, Which panel driver to be used ? the Frame-buffer driver or DRM driver?

Referring to the document i.MX Linux reference Manual (4.14.98)

In Section 6.2.2 Frame Buffer

Frame buffer drivers are supported for i.MX 6 and i.MX 7 but not for i.MX 8.

In Section 6.4.2 MIPI DSI Interface

6.4.2.2 Source Code Structure
Table below shows the MIPI DSI driver source files available in drivers/video/fbdev/mxc.
Table 64. MIPI DSI Driver Files
File Description
drveirs/video/fbdev/mxc/mipi_dsi.c                                        MIPI DSI IP Frame buffer driver source file
drivers/video/fbdev/mxc/mipi_dsi.h                                        MIPI DSI IP Frame bufferdriver header file
drivers/video/fbdev/mxc/mxcfb_hx8369_wvga.c                   MIPI DSI Frame bufferDisplay Panel driver source file
drivers/video/fbdev/mxc/mipi_dsi_samsung.c                       MIPI DSI Frame buffer Samsung source file
drivers/video/fbdev/mxc/mipi_dsi_northwest.c                      MIPI DSI Frame buffer Northwest source file
drivers/video/fbdev/mxc/mxcfb_hx8363_wvga.c                   i.MX 7 Frame buffer Truly WVGA Panel TFT3P5581E
drivers/video/fbdev/mxc/mxcfb_hx8369_wvga.c                   i.MX 6 Frame buffer Truly WVGA sync panel
drivers/video/fbdev/mxc/mxcfb_otm808b_wvga.c                 Truly Frame buffer WVGA Panel TFT3P5079E
drivers/gpu/drm/imx/sec_mipi_dsmi-imx.c Samsung            DRM driver
drivers/gpu/drm/imx/nwl_dsi-imx.c Northwest                        DRM driver

in this list there are no references for DRM based MIPI panels drivers. This creates a confusion that on iMX8M mini which driver to be used for MIPI_DSI panels. Is that errata in the Manual? kindly update us.

[thiago_machado]

Hi! I'm working with a IMX 8M Nano EVK, and I'd like to know where are located the drivers. I'm trying to bringup a MIPI LCD display that uses a different MIPI controller found in the DSI_OLED Display made by NXP. I'm getting all files to build my image from https://source.codeaurora.org/external/imx/imx-manifest and as reference I'm using the i.MX Yocto Project User's Guide. Is possible to edit/add drivers from a given BSP?

[igorpadykov]

Hi Prasanna

for i.MX8M Mini one can look at ..gpu/drm/bridge/sec-dsim.c

sec-dsim.c\bridge\drm\gpu\drivers - linux-imx - i.MX Linux kernel 

Best regards
igor
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[prasannakulkarni]

Hi igor,

We are not using mipi bridge... Directly mipi dsi to panel... In this case what driver need to be used.... 

[igorpadykov]

then it is

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

Best regards
igor

[prasannakulkarni]

Hi igor,

Then it is clear that from i.MX8 onward DRM based display drivers are supported not Frame Buffer based,  correct me if I am wrong? as per doc i.MX Linux reference Manual (4.14.98)

In Section 6.2.2 Frame Buffer

 Frame buffer drivers are supported for i.MX 6 and i.MX 7 but not for i.MX 8.

but driver panel-raydium-rm67191.c is not listed in source code (6.4.2.2 Source Code Structure) structure of the doc that creates confusion.