Can't get custom LCD to work on BB-G and latest Debian 7.9 (2015-11-12)

I’ve spent a couple of days on this and can’t say I’ve made any progress. I have a custom LCD cape modeled after the 4D-Systems LCD7. It has the same LCD connections, just doesn’t have the touchscreen, leds or buttons (and no Enable line either).

If I enable BB-BONE-LCD7-01:00A3 I get a single screen worth of data, sometimes just the mouse pointer, sometimes the touch screen calibration but regardless of what it is, it fades away to either black or to a half-white / half-black screen. I was encouraged by this and figured I just had to change the timings in the device tree to make it work.

I downloaded the latest overlays from git ( but what I’ve found is that if I simply copy BB-BONE-LCD7-01-00A3.dts to BB-BONE-LCD7-01-00A7.dts, change the version string in it from A3 to A7, rebuild, install and activate at boot (changing uEnv.txt) it won’t load.

The error in dmesg is: of_resolve: Could not find symbol ‘gpio0’. This in and of itself is no big deal because the entry in question is for the ‘Enter’ button which I don’t need. In fact I’ve removed the device tree entries for the touchscreen and the button GPIOs but that just shows other issues. Significantly, I get complaints that the ‘display-timings’ node is missing, which it is not.

The bottom line is that the device tree sources in git are obviously not the ones compiled into the 7.9 distribution or I’m missing something. The notes at only mention the 4.1 kernel. Is there another source or branch for the 3.8 kernel?. I’d prefer the 3.8 kernel because this is just one component of a project that includes using other hardware and a driver that I don’t yet have working on 4.1 but if I need to update to 4.1 then so be it.

I’m just looking for a little guidance before I spend even more time going down the wrong path.


– Mike Fallavollita