Kernel driver MCP3021
  ======================
  
  Supported chips:
    * Microchip Technology MCP3021
      Prefix: 'mcp3021'
      Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/21805a.pdf
    * Microchip Technology MCP3221
      Prefix: 'mcp3221'
      Datasheet: http://ww1.microchip.com/downloads/en/DeviceDoc/21732c.pdf
  
  Authors:
     Mingkai Hu
     Sven Schuchmann <schuchmann@schleissheimer.de>
  
  Description
  -----------
  
  This driver implements support for the Microchip Technology MCP3021 and
  MCP3221 chip.
  
  The Microchip Technology Inc. MCP3021 is a successive approximation A/D
  converter (ADC) with 10-bit resolution. The MCP3221 has 12-bit resolution.
  
  These devices provide one single-ended input with very low power consumption.
  Communication to the MCP3021/MCP3221  is performed using a 2-wire I2C
  compatible interface. Standard (100 kHz) and Fast (400 kHz) I2C modes are
  available. The default I2C device address is 0x4d (contact the Microchip
  factory for additional address options).