| 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. |