Prefix: 'tc654' Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/20001734C.pdfAuthors: Chris Packham <chris.packham@alliedtelesis.co.nz> Masahiko Iwamoto <iwamoto@allied-telesis.co.jp>Description-----------This driver implements support for the Microchip TC654 and TC655.The TC654 uses the 2-wire interface compatible with the SMBUS 2.0specification. The TC654 has two (2) inputs for measuring fan RPM andone (1) PWM output which can be used for fan control.Configuration Notes-------------------Ordinarily the pwm1_mode ABI is used for controlling the pwm outputmode. However, for this chip the output is always pwm, and thepwm1_mode determines if the pwm output is controlled via the pwm1 valueor via the Vin analog input.Setting pwm1_mode to 1 will cause the pwm output to be driven based onthe pwm1 value. Setting pwm1_mode to 0 will cause the pwm output to bedriven based on the Vin input.