TinyRex LVDS Display

[blueprint]

Hi,

I'm trying to figure out what changes would be necessary to disable the HDMI display and enable the LVDS display (single channel)?

Also, if I want to change the resolution of the display in u-boot (as well as enabling LVDS), can this be done using the environment variables or do I need to rebuild and re-flash u-boot? We are targeting a micro-display with an 800x600 resolution.

Thanks in advance!

[marek]

Enabling/disabling/configuring display outputs is possible over kernel command line. Best source is official documentation (https://www.nxp.com/webapp/Download?...0-LINUX-DOCS):

i.MX_Linux_User's_Guide.pdf
i.MX_Linux_Release_Notes.pdf
i.MX_BSP_Porting_Guide.pdf

Some examples:

The kernel command line for 24-bit LVDS panel (4 pairs of LVDS data signals) displays
the following line if the panel is properly connected:

video=mxcfb0:dev=ldb,if=RGB24

The kernel command line for 18-bit LVDS panel (3 pairs of LVDS data signals) displays
the following line if the panel is properly connected:

video=mxcfb0:dev=ldb,if=RGB666

Tells the kernel/driver which resolution/depth and refresh rate should be used for display port 0 or 1.
See the parameter information under Documentation/fb/modedb.txt

1. video=mxcfb0:dev=hdmi,[email protected],if=RGB24 video=mxcfb1:dev=ldb,if=RGB666
2. video=mxcfb0:dev=ldb,if=RGB666 video=mxcfb1:dev=hdmi,[email protected],if=RGB24
3. video=mxcfb0:dev=hdmi,[email protected],if=RGB24
4. video=mxcfb0:dev=ldb,if=RGB666
5. video=mxcfb0:dev=lcd,CLAA-WVGA,if=RGB656
6. video=mxcfb0:dev=mipi_dsi,TRULY-WVGA,if=RGB24

LVDS support in u-boot is untested. This change will definitely require u-boot recompilation.
The "board/freescale/mx6sabresd/mx6sabresd.c" is NXP reference platform and it contains support for "Hannstar-XGA" with is lvds panel. This source code must be ported/copied/modified including surrounding configuration. But there is still chance that it won't work as intended.