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  Kernel driver emc1403
  =====================
  
  Supported chips:
    * SMSC / Microchip EMC1402, EMC1412
      Addresses scanned: I2C 0x18, 0x1c, 0x29, 0x4c, 0x4d, 0x5c
      Prefix: 'emc1402'
      Datasheets:
  	http://ww1.microchip.com/downloads/en/DeviceDoc/1412.pdf
  	http://ww1.microchip.com/downloads/en/DeviceDoc/1402.pdf
    * SMSC / Microchip EMC1403, EMC1404, EMC1413, EMC1414
      Addresses scanned: I2C 0x18, 0x29, 0x4c, 0x4d
      Prefix: 'emc1403', 'emc1404'
      Datasheets:
  	http://ww1.microchip.com/downloads/en/DeviceDoc/1403_1404.pdf
  	http://ww1.microchip.com/downloads/en/DeviceDoc/1413_1414.pdf
    * SMSC / Microchip EMC1422
      Addresses scanned: I2C 0x4c
      Prefix: 'emc1422'
      Datasheet:
  	http://ww1.microchip.com/downloads/en/DeviceDoc/1422.pdf
    * SMSC / Microchip EMC1423, EMC1424
      Addresses scanned: I2C 0x4c
      Prefix: 'emc1423', 'emc1424'
      Datasheet:
  	http://ww1.microchip.com/downloads/en/DeviceDoc/1423_1424.pdf
  
  Author:
      Kalhan Trisal <kalhan.trisal@intel.com
  
  
  Description
  -----------
  
  The Standard Microsystems Corporation (SMSC) / Microchip EMC14xx chips
  contain up to four temperature sensors. EMC14x2 support two sensors
  (one internal, one external). EMC14x3 support three sensors (one internal,
  two external), and EMC14x4 support four sensors (one internal, three
  external).
  
  The chips implement three limits for each sensor: low (tempX_min), high
  (tempX_max) and critical (tempX_crit.) The chips also implement an
  hysteresis mechanism which applies to all limits. The relative difference
  is stored in a single register on the chip, which means that the relative
  difference between the limit and its hysteresis is always the same for
  all three limits.
  
  This implementation detail implies the following:
  * When setting a limit, its hysteresis will automatically follow, the
    difference staying unchanged. For example, if the old critical limit
    was 80 degrees C, and the hysteresis was 75 degrees C, and you change
    the critical limit to 90 degrees C, then the hysteresis will
    automatically change to 85 degrees C.
  * The hysteresis values can't be set independently. We decided to make
    only temp1_crit_hyst writable, while all other hysteresis attributes
    are read-only. Setting temp1_crit_hyst writes the difference between
    temp1_crit_hyst and temp1_crit into the chip, and the same relative
    hysteresis applies automatically to all other limits.
  * The limits should be set before the hysteresis.