Manual Pages  — PCF8591

Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):

pcf8591_load="YES"

The pcf8591 driver reports data via sysctl(8) entries in the device's node in the sysctl(8) tree:

inputs.%d
	The input level of the corresponding input in steps between 0 and 255. Absolute voltage depends on an actual reference voltage.

On an FDT(4) based system the following properties must be set:

compatible
	Must be set to "nxp,pcf8591".
reg
	The I2C address of pcf8591. It should be in the range from 0x40 to 0x4f (7-bit).

The DTS part for a pcf8591 device usually looks like:

/ {

        ...
        pcf8591adc {
                compatible = "nxp,pcf8591";
                reg = <0x48>;
        };
};