Getting an LCD-Display to Work with 24 bits on an Beaglebone Black

[har...@t-online.de]

Hello together,

I am new to Beaglebone Black (and embedded linux).

I am trying to get an external LCD with 18bit or 24bit Interface to work on the Beaglebone Black. The LCD I am using is a Kyocera T-55343GD035JU-LW-ADN with 320x240 pixel and 24 bit colordepth. (http://www.kyocera-display.com/products/partdetail.asp?PartNumber=T-55343GD035JU-LW-ADN)

I wrote my own Devicetree-Overlay based on cape-bone-lcd3-00A0.dts at /lib/firmware without the Touchscreen and Keys, but have added the additional pins for lcd_data 16 to 23 and changed the bpp in the panel info to 24. The LCD itself works and it boot to the GUI on Angström or Debian, but i only get lcd_data 0 -15 to work.
When I add "video=LVDS-1:320x240-24@60" to the uEnv.txt file like it is written here: http://elinux.org/24bit_LCD_for_BBB, I get many errors in dmesg starting with "[    4.185659] WARNING: at drivers/gpu/drm/tilcdc/tilcdc_crtc.c:245 tilcdc_crtc_mode_set+0x2f/0x460()" So this doesnt work.

Changing the DefaultDepth at X11 config file changes the color-order from RGB to BGR (how it should be at 24bit) at least with the Angstrom OS. At Debian the Xserver doesnt start any more with this option. At Angstrom the color-order is fine but the bits 16 to 23 doesnt work at all (No Data on this lines).

I also tried to change the depth of the framebuffer with fbset -depth 24 but get only the error : "fbset: FBIOPUT_VSCREENINFO: Invalid argument"

When I read the documentation of the fbdev driver at the ti website, there is written that the beaglebone should work at 24 (or 32 bit) without any Probems. (Here http://processors.wiki.ti.com/index.php/AM335x_LCD_Controller_Driver%27s_Guide and here http://processors.wiki.ti.com/index.php/Linux_Core_LCD_Controller_User_Guide#AM335x_LCDC_Display_Driver_.28DRM.29)

What am I doing wrong? Can anyone please try to help me find my errors?

Thanks for your help

Harald

[Jimmy Lee]

Hi Harald,

Did you get it work? I also got the same issue. Can you share your experience?

Thanks,

Jimmy

Harald Funk於 2014年11月5日星期三 UTC+8上午3時09分45秒寫道：

[Florian Lebrun]

Hi Harald,

I have same issue, do you find the solution please ? 

thanks a lot