1 Kernel driver ds620 1 Kernel driver ds620
2 =================== 2 ===================
3 3
4 Supported chips: 4 Supported chips:
5 5
6 * Dallas Semiconductor DS620 6 * Dallas Semiconductor DS620
7 7
8 Prefix: 'ds620' 8 Prefix: 'ds620'
9 9
10 Datasheet: Publicly available at the Dalla 10 Datasheet: Publicly available at the Dallas Semiconductor website
11 11
12 http://www.dalsemi.com/ 12 http://www.dalsemi.com/
13 13
14 Authors: 14 Authors:
15 Roland Stigge <stigge@antcom.de> 15 Roland Stigge <stigge@antcom.de>
16 based on ds1621.c by 16 based on ds1621.c by
17 Christian W. Zuckschwerdt <zany@triq.ne 17 Christian W. Zuckschwerdt <zany@triq.net>
18 18
19 Description 19 Description
20 ----------- 20 -----------
21 21
22 The DS620 is a (one instance) digital thermome 22 The DS620 is a (one instance) digital thermometer and thermostat. It has both
23 high and low temperature limits which can be u 23 high and low temperature limits which can be user defined (i.e. programmed
24 into non-volatile on-chip registers). Temperat 24 into non-volatile on-chip registers). Temperature range is -55 degree Celsius
25 to +125. Between 0 and 70 degree Celsius, accu 25 to +125. Between 0 and 70 degree Celsius, accuracy is 0.5 Kelvin. The value
26 returned via sysfs displays post decimal posit 26 returned via sysfs displays post decimal positions.
27 27
28 The thermostat function works as follows: When 28 The thermostat function works as follows: When configured via platform_data
29 (struct ds620_platform_data) .pomode == 0 (def 29 (struct ds620_platform_data) .pomode == 0 (default), the thermostat output pin
30 PO is always low. If .pomode == 1, the thermos 30 PO is always low. If .pomode == 1, the thermostat is in PO_LOW mode. I.e., the
31 output pin PO becomes active when the temperat 31 output pin PO becomes active when the temperature falls below temp1_min and
32 stays active until the temperature goes above 32 stays active until the temperature goes above temp1_max.
33 33
34 Likewise, with .pomode == 2, the thermostat is 34 Likewise, with .pomode == 2, the thermostat is in PO_HIGH mode. I.e., the PO
35 output pin becomes active when the temperature 35 output pin becomes active when the temperature goes above temp1_max and stays
36 active until the temperature falls below temp1 36 active until the temperature falls below temp1_min.
37 37
38 The PO output pin of the DS620 operates active 38 The PO output pin of the DS620 operates active-low.
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