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Roland Stigge60994692011-01-09 09:31:39 -05001Kernel driver ds620
2===================
3
4Supported chips:
5 * Dallas Semiconductor DS620
6 Prefix: 'ds620'
7 Datasheet: Publicly available at the Dallas Semiconductor website
8 http://www.dalsemi.com/
9
10Authors:
11 Roland Stigge <stigge@antcom.de>
12 based on ds1621.c by
13 Christian W. Zuckschwerdt <zany@triq.net>
14
15Description
16-----------
17
18The DS620 is a (one instance) digital thermometer and thermostat. It has both
19high and low temperature limits which can be user defined (i.e. programmed
20into non-volatile on-chip registers). Temperature range is -55 degree Celsius
21to +125. Between 0 and 70 degree Celsius, accuracy is 0.5 Kelvin. The value
22returned via sysfs displays post decimal positions.
23
24The thermostat function works as follows: When configured via platform_data
25(struct ds620_platform_data) .pomode == 0 (default), the thermostat output pin
26PO is always low. If .pomode == 1, the thermostat is in PO_LOW mode. I.e., the
27output pin PO becomes active when the temperature falls below temp1_min and
28stays active until the temperature goes above temp1_max.
29
30Likewise, with .pomode == 2, the thermostat is in PO_HIGH mode. I.e., the PO
31output pin becomes active when the temperature goes above temp1_max and stays
32active until the temperature falls below temp1_min.
33
34The PO output pin of the DS620 operates active-low.