| Kernel driver ds620 | 
 | =================== | 
 |  | 
 | Supported chips: | 
 |   * Dallas Semiconductor DS620 | 
 |     Prefix: 'ds620' | 
 |     Datasheet: Publicly available at the Dallas Semiconductor website | 
 |                http://www.dalsemi.com/ | 
 |  | 
 | Authors: | 
 |         Roland Stigge <stigge@antcom.de> | 
 |         based on ds1621.c by | 
 |         Christian W. Zuckschwerdt <zany@triq.net> | 
 |  | 
 | Description | 
 | ----------- | 
 |  | 
 | The DS620 is a (one instance) digital thermometer and thermostat. It has both | 
 | high and low temperature limits which can be user defined (i.e.  programmed | 
 | into non-volatile on-chip registers). Temperature range is -55 degree Celsius | 
 | to +125. Between 0 and 70 degree Celsius, accuracy is 0.5 Kelvin. The value | 
 | returned via sysfs displays post decimal positions. | 
 |  | 
 | The thermostat function works as follows: When configured via platform_data | 
 | (struct ds620_platform_data) .pomode == 0 (default), the thermostat output pin | 
 | PO is always low. If .pomode == 1, the thermostat is in PO_LOW mode. I.e., the | 
 | output pin PO becomes active when the temperature falls below temp1_min and | 
 | stays active until the temperature goes above temp1_max. | 
 |  | 
 | Likewise, with .pomode == 2, the thermostat is in PO_HIGH mode. I.e., the PO | 
 | output pin becomes active when the temperature goes above temp1_max and stays | 
 | active until the temperature falls below temp1_min. | 
 |  | 
 | The PO output pin of the DS620 operates active-low. |