NAME
amdisplay, nxphdmi
— Texas Instruments AM335x LCD
display driver
SYNOPSIS
amdisplay* at simplebus0 |
nxphdmi* at iic* |
wsdisplay* at amdisplay* |
DESCRIPTION
The amdisplay driver supports the LCD
controller integrated in Texas Instruments' line of AM335x SoCs. The LCDC
reads a framebuffer from memory via DMA and scans it out at the proper
frequency to suit a display (along with the necessary hsync/vsync/etc.
signals) to a PHY transmitter. The BeagleBone Black uses NXP/Freescale's
TDA19988 HDMI transmitter, which is additionally supported by the
nxphdmi driver.
SEE ALSO
HISTORY
The amdisplay driver first appeared in
OpenBSD 6.2.
AUTHORS
The amdisplay driver was written by
Ian Sutton
<ians@openbsd.org>.
The nxphdmi driver was written by
Oleksandr Tymoshenko
<gonzo@freebsd.org>
and later ported to OpenBSD.
CAVEATS
On the BeagleBone Black, the LCDC and onboard eMMC NAND chip share
the same set of pads such that only one can be wired and used at a time. To
boot from or use the onboard storage, disable
amdisplay via
config(8)
in the kernel.
A display must be attached at boot time, otherwise
amdisplay will fail to configure.
Hotplugging is not supported.
Only 16-bit color depth is supported due to a silicon bug.