One of [Sprite_tm]’s colleagues recently challenged him to connect a small LCD touch screen to a Raspberry Pi. Sadly, [Sprite_tm] has yet to take delivery of a Raspberry Pi, but he did manage to connect an LCD to a Linux board without video capabilities.
Because [Sprite_tm]’s display has a 16-bit parallel interface, and 16 GPIO pins are hard to come by on the Carambola Linux board, a few shift registers had to be brought into the build to make the LCD work. These shift registers are connected to the Carambola board via an SPI interface; a very simple way to connect all the LCD pins to the Linux board.
Of course, there’s no way for Linux to speak to the LCD without a kernel driver; [Sprite_tm] wrote a framebuffer driver so the LCD can be used as a console, an X session, or used by any other program that can write to a framebuffer device.
Like all good driver authors, [Sprite_tm] is giving away the patch to enable SPI-ified LCD panels on the Carambola along with the shift register schematic. With any luck we’ll also see the Raspi drivers when [Sprite_tm] takes delivery of his Raspberry Pi.