Needs more testing and an appropriate API for such (non-audio) DACs. For now
one can set the output value using sysctl node. Also sysmon(4) will conveniently
report the voltage on Vout pin of the DAC. Note that this is not an actual
measured voltage, but merely calculated using equation from datasheet. Real
voltage might be different and depend on analog circuitry attached to the DAC.
a sample driver for the TI TMP121 temperature sensor. This has been
moderately tested on Au1550, and it is not enabled in sys/conf (yet). So
the change is harmless at worst, and useful at best.
Alchemy Au1550 bus driver forthcoming, along with a driver for SPI flash
devices, such as found on the Meraki Mini
This development was partially funded by the Champaign-Urbana Community
Wireless Network Project.
Note that there are some MD-specific SPI drivers that could probably be
made MI under this new framework.
