mcp980x —
Microchip 9800/1/2/3 I2C temperature sensor driver
mcp980x* at iic? addr 0x48
The mcp980x driver provides support for the MCP980x
  series of temperature sensors. It allows reporting ambient temperature through
  the envsys(4) API.
The following sysctl(3) variable
  are provided:
  - machdep.mcp980x0.res
- ADC resolution (integer). Valid values are 0-3, where 0 is 9-bit (0.5
      Celsius degree) and 3 is 12-bit (0.0625 Celsius degree) resolution.
- machdep.mcp980x0.templimit
- If the ambient temperature exceeds this limit, the chip asserts an alert
      line (integer).
- machdep.mcp980x0.hysteresis
- Hysteresis for temperature limit (integer).
Themcp980x device first appeared in
  NetBSD 7.0.
MCP9804 and MCP9805 chip are different and is supported by the
  sdtemp(4) driver.
The MCP980x chip supports hysteresis and temperature limit values
    with a resolution of 0.5 Celsius degree, however the
    mcp980x driver supports setting only integer
  values.