Commit | Line | Data |
---|---|---|
60994698 RS |
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. |