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f22aaaa70   Donggeun Kim   hwmon: Driver for... 
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  Kernel driver ntc_thermistor
  =================
  
  Supported thermistors:
  * Murata NTC Thermistors NCP15WB473, NCP18WB473, NCP21WB473, NCP03WB473, NCP15WL333
    Prefixes: 'ncp15wb473', 'ncp18wb473', 'ncp21wb473', 'ncp03wb473', 'ncp15wl333'
    Datasheet: Publicly available at Murata
  
  Other NTC thermistors can be supported simply by adding compensation
  tables; e.g., NCP15WL333 support is added by the table ncpXXwl333.
  
  Authors:
  	MyungJoo Ham <myungjoo.ham@samsung.com>
  
  Description
  -----------
  
  The NTC thermistor is a simple thermistor that requires users to provide the
  resistance and lookup the corresponding compensation table to get the
  temperature input.
  
  The NTC driver provides lookup tables with a linear approximation function
  and four circuit models with an option not to use any of the four models.
  
  The four circuit models provided are:
  
  	$: resister, [TH]: the thermistor
  
   1. connect = NTC_CONNECTED_POSITIVE, pullup_ohm > 0
  
     [pullup_uV]
         |    |
        [TH]  $ (pullup_ohm)
         |    |
         +----+-----------------------[read_uV]
         |
         $ (pulldown_ohm)
         |
        --- (ground)
  
   2. connect = NTC_CONNECTED_POSITIVE, pullup_ohm = 0 (not-connected)
  
     [pullup_uV]
         |
        [TH]
         |
         +----------------------------[read_uV]
         |
         $ (pulldown_ohm)
         |
        --- (ground)
  
   3. connect = NTC_CONNECTED_GROUND, pulldown_ohm > 0
  
     [pullup_uV]
         |
         $ (pullup_ohm)
         |
         +----+-----------------------[read_uV]
         |    |
        [TH]  $ (pulldown_ohm)
         |    |
        -------- (ground)
  
   4. connect = NTC_CONNECTED_GROUND, pulldown_ohm = 0 (not-connected)
  
     [pullup_uV]
         |
         $ (pullup_ohm)
         |
         +----------------------------[read_uV]
         |
        [TH]
         |
        --- (ground)
  
  When one of the four circuit models is used, read_uV, pullup_uV, pullup_ohm,
  pulldown_ohm, and connect should be provided. When none of the four models
  are suitable or the user can get the resistance directly, the user should
  provide read_ohm and _not_ provide the others.
  
  Sysfs Interface
  ---------------
  name		the mandatory global attribute, the thermistor name.
  
  temp1_type	always 4 (thermistor)
  		RO
  
  temp1_input	measure the temperature and provide the measured value.
  		(reading this file initiates the reading procedure.)
  		RO
  
  Note that each NTC thermistor has only _one_ thermistor; thus, only temp1 exists.