| Roland Stigge | 6099469 | 2011-01-09 09:31:39 -0500 | [diff] [blame] | 1 | Kernel driver ds620 |
| 2 | =================== |
| 3 | |
| 4 | Supported chips: |
| 5 | * Dallas Semiconductor DS620 |
| 6 | Prefix: 'ds620' |
| 7 | Datasheet: Publicly available at the Dallas Semiconductor website |
| 8 | http://www.dalsemi.com/ |
| 9 | |
| 10 | Authors: |
| 11 | Roland Stigge <stigge@antcom.de> |
| 12 | based on ds1621.c by |
| 13 | Christian W. Zuckschwerdt <zany@triq.net> |
| 14 | |
| 15 | Description |
| 16 | ----------- |
| 17 | |
| 18 | The DS620 is a (one instance) digital thermometer and thermostat. It has both |
| 19 | high and low temperature limits which can be user defined (i.e. programmed |
| 20 | into non-volatile on-chip registers). Temperature range is -55 degree Celsius |
| 21 | to +125. Between 0 and 70 degree Celsius, accuracy is 0.5 Kelvin. The value |
| 22 | returned via sysfs displays post decimal positions. |
| 23 | |
| 24 | The thermostat function works as follows: When configured via platform_data |
| 25 | (struct ds620_platform_data) .pomode == 0 (default), the thermostat output pin |
| 26 | PO is always low. If .pomode == 1, the thermostat is in PO_LOW mode. I.e., the |
| 27 | output pin PO becomes active when the temperature falls below temp1_min and |
| 28 | stays active until the temperature goes above temp1_max. |
| 29 | |
| 30 | Likewise, with .pomode == 2, the thermostat is in PO_HIGH mode. I.e., the PO |
| 31 | output pin becomes active when the temperature goes above temp1_max and stays |
| 32 | active until the temperature falls below temp1_min. |
| 33 | |
| 34 | The PO output pin of the DS620 operates active-low. |