gpioow(4), attaching a bit-banging driver via a GPIO pin. Also,
owtemp(4) which supports some of the 1-Wire temperature sensors, including
the DS18b20 and DS1920 - temperatures are returned via the envsys(4)
framework.
Original drivers by Alexander Yurchenko (grange@openbsd), with envsys(4)
support and a fix to the 1-wire search algorithm (for discovering
devices on the bus) by me.
As discussed on tech-kern earlier this week.
riz