1*7ebd8b66SMauro Carvalho ChehabKernel driver ds620 2*7ebd8b66SMauro Carvalho Chehab=================== 3*7ebd8b66SMauro Carvalho Chehab 4*7ebd8b66SMauro Carvalho ChehabSupported chips: 5*7ebd8b66SMauro Carvalho Chehab 6*7ebd8b66SMauro Carvalho Chehab * Dallas Semiconductor DS620 7*7ebd8b66SMauro Carvalho Chehab 8*7ebd8b66SMauro Carvalho Chehab Prefix: 'ds620' 9*7ebd8b66SMauro Carvalho Chehab 10*7ebd8b66SMauro Carvalho Chehab Datasheet: Publicly available at the Dallas Semiconductor website 11*7ebd8b66SMauro Carvalho Chehab 12*7ebd8b66SMauro Carvalho Chehab http://www.dalsemi.com/ 13*7ebd8b66SMauro Carvalho Chehab 14*7ebd8b66SMauro Carvalho ChehabAuthors: 15*7ebd8b66SMauro Carvalho Chehab Roland Stigge <stigge@antcom.de> 16*7ebd8b66SMauro Carvalho Chehab based on ds1621.c by 17*7ebd8b66SMauro Carvalho Chehab Christian W. Zuckschwerdt <zany@triq.net> 18*7ebd8b66SMauro Carvalho Chehab 19*7ebd8b66SMauro Carvalho ChehabDescription 20*7ebd8b66SMauro Carvalho Chehab----------- 21*7ebd8b66SMauro Carvalho Chehab 22*7ebd8b66SMauro Carvalho ChehabThe DS620 is a (one instance) digital thermometer and thermostat. It has both 23*7ebd8b66SMauro Carvalho Chehabhigh and low temperature limits which can be user defined (i.e. programmed 24*7ebd8b66SMauro Carvalho Chehabinto non-volatile on-chip registers). Temperature range is -55 degree Celsius 25*7ebd8b66SMauro Carvalho Chehabto +125. Between 0 and 70 degree Celsius, accuracy is 0.5 Kelvin. The value 26*7ebd8b66SMauro Carvalho Chehabreturned via sysfs displays post decimal positions. 27*7ebd8b66SMauro Carvalho Chehab 28*7ebd8b66SMauro Carvalho ChehabThe thermostat function works as follows: When configured via platform_data 29*7ebd8b66SMauro Carvalho Chehab(struct ds620_platform_data) .pomode == 0 (default), the thermostat output pin 30*7ebd8b66SMauro Carvalho ChehabPO is always low. If .pomode == 1, the thermostat is in PO_LOW mode. I.e., the 31*7ebd8b66SMauro Carvalho Chehaboutput pin PO becomes active when the temperature falls below temp1_min and 32*7ebd8b66SMauro Carvalho Chehabstays active until the temperature goes above temp1_max. 33*7ebd8b66SMauro Carvalho Chehab 34*7ebd8b66SMauro Carvalho ChehabLikewise, with .pomode == 2, the thermostat is in PO_HIGH mode. I.e., the PO 35*7ebd8b66SMauro Carvalho Chehaboutput pin becomes active when the temperature goes above temp1_max and stays 36*7ebd8b66SMauro Carvalho Chehabactive until the temperature falls below temp1_min. 37*7ebd8b66SMauro Carvalho Chehab 38*7ebd8b66SMauro Carvalho ChehabThe PO output pin of the DS620 operates active-low. 39