LCD/VGA driver for BBB on 3.8.13-40


I am running the RobertCNelson’s Ubuntu image with 3.8.13-bone40.1 kernel. The device is a BBB “clone” with LCD to VGA hookup via ADV7125 video encoder. Should be somewhat roughly equivalent to an LCD cape. The customer requirement was to support DVI-I, so analog output was needed to satisfy.

It seems that by default there is no signal on the LCD pins, only the HDMI. I tried disabling the HDMI drivers, and enabling one of the LCD7 overlays (they don’t seem to be able to co-exist, one must be disabled for the other to be enabled):

optargs=capemgr.disable_partno=BB-BONELT-HDMI,BB-BONE-EMMC-2G,BB-BONELT-HDMIN capemgr.enable_partno=BB-UART1,BB-I2C1,BB-BONE-LCD7-01:00A2:8

This seems to somewhat work (the VGA monitor gets signal), except there is support for 800x480 resolution only:

xrandr -d :0

Screen 0: minimum 320 x 200, current 800 x 480, maximum 2048 x 2048

LVDS-0 connected 800x480+0+0 (normal left inverted right x axis y axis) 0mm x 0mm

800x480 61.5*+

Is there a default setting I can change to allow for a wider range of resolutions? Do I have to load an LCD cape overlay, or can I simply enable the LCD output by not loading the HDMI drivers? Can I affect/force another resolution?


Looks like I can use a DVI “cape” overlay, cape-bone-dvi, which provides more resolutions choices. I need to make my own overlay now, as our setup is slightly different, we use i2c1 and don’t have LEDs.