ds620.rst (1339B)
1Kernel driver ds620 2=================== 3 4Supported chips: 5 6 * Dallas Semiconductor DS620 7 8 Prefix: 'ds620' 9 10 Datasheet: Publicly available at the Dallas Semiconductor website 11 12 http://www.dalsemi.com/ 13 14Authors: 15 Roland Stigge <stigge@antcom.de> 16 based on ds1621.c by 17 Christian W. Zuckschwerdt <zany@triq.net> 18 19Description 20----------- 21 22The DS620 is a (one instance) digital thermometer and thermostat. It has both 23high and low temperature limits which can be user defined (i.e. programmed 24into non-volatile on-chip registers). Temperature range is -55 degree Celsius 25to +125. Between 0 and 70 degree Celsius, accuracy is 0.5 Kelvin. The value 26returned via sysfs displays post decimal positions. 27 28The thermostat function works as follows: When configured via platform_data 29(struct ds620_platform_data) .pomode == 0 (default), the thermostat output pin 30PO is always low. If .pomode == 1, the thermostat is in PO_LOW mode. I.e., the 31output pin PO becomes active when the temperature falls below temp1_min and 32stays active until the temperature goes above temp1_max. 33 34Likewise, with .pomode == 2, the thermostat is in PO_HIGH mode. I.e., the PO 35output pin becomes active when the temperature goes above temp1_max and stays 36active until the temperature falls below temp1_min. 37 38The PO output pin of the DS620 operates active-low.