1*4882a593SmuzhiyunKernel driver ltc2990 2*4882a593Smuzhiyun===================== 3*4882a593Smuzhiyun 4*4882a593Smuzhiyun 5*4882a593SmuzhiyunSupported chips: 6*4882a593Smuzhiyun 7*4882a593Smuzhiyun * Linear Technology LTC2990 8*4882a593Smuzhiyun 9*4882a593Smuzhiyun Prefix: 'ltc2990' 10*4882a593Smuzhiyun 11*4882a593Smuzhiyun Addresses scanned: - 12*4882a593Smuzhiyun 13*4882a593Smuzhiyun Datasheet: http://www.linear.com/product/ltc2990 14*4882a593Smuzhiyun 15*4882a593Smuzhiyun 16*4882a593Smuzhiyun 17*4882a593SmuzhiyunAuthor: 18*4882a593Smuzhiyun 19*4882a593Smuzhiyun - Mike Looijmans <mike.looijmans@topic.nl> 20*4882a593Smuzhiyun - Tom Levens <tom.levens@cern.ch> 21*4882a593Smuzhiyun 22*4882a593Smuzhiyun 23*4882a593SmuzhiyunDescription 24*4882a593Smuzhiyun----------- 25*4882a593Smuzhiyun 26*4882a593SmuzhiyunLTC2990 is a Quad I2C Voltage, Current and Temperature Monitor. 27*4882a593SmuzhiyunThe chip's inputs can measure 4 voltages, or two inputs together (1+2 and 3+4) 28*4882a593Smuzhiyuncan be combined to measure a differential voltage, which is typically used to 29*4882a593Smuzhiyunmeasure current through a series resistor, or a temperature with an external 30*4882a593Smuzhiyundiode. 31*4882a593Smuzhiyun 32*4882a593Smuzhiyun 33*4882a593SmuzhiyunUsage Notes 34*4882a593Smuzhiyun----------- 35*4882a593Smuzhiyun 36*4882a593SmuzhiyunThis driver does not probe for PMBus devices. You will have to instantiate 37*4882a593Smuzhiyundevices explicitly. 38*4882a593Smuzhiyun 39*4882a593Smuzhiyun 40*4882a593SmuzhiyunSysfs attributes 41*4882a593Smuzhiyun---------------- 42*4882a593Smuzhiyun 43*4882a593Smuzhiyun============= ================================================== 44*4882a593Smuzhiyunin0_input Voltage at Vcc pin in millivolt (range 2.5V to 5V) 45*4882a593Smuzhiyuntemp1_input Internal chip temperature in millidegrees Celsius 46*4882a593Smuzhiyun============= ================================================== 47*4882a593Smuzhiyun 48*4882a593SmuzhiyunA subset of the following attributes are visible, depending on the measurement 49*4882a593Smuzhiyunmode of the chip. 50*4882a593Smuzhiyun 51*4882a593Smuzhiyun============= ========================================================== 52*4882a593Smuzhiyunin[1-4]_input Voltage at V[1-4] pin in millivolt 53*4882a593Smuzhiyuntemp2_input External temperature sensor TR1 in millidegrees Celsius 54*4882a593Smuzhiyuntemp3_input External temperature sensor TR2 in millidegrees Celsius 55*4882a593Smuzhiyuncurr1_input Current in mA across V1-V2 assuming a 1mOhm sense resistor 56*4882a593Smuzhiyuncurr2_input Current in mA across V3-V4 assuming a 1mOhm sense resistor 57*4882a593Smuzhiyun============= ========================================================== 58*4882a593Smuzhiyun 59*4882a593SmuzhiyunThe "curr*_input" measurements actually report the voltage drop across the 60*4882a593Smuzhiyuninput pins in microvolts. This is equivalent to the current through a 1mOhm 61*4882a593Smuzhiyunsense resistor. Divide the reported value by the actual sense resistor value 62*4882a593Smuzhiyunin mOhm to get the actual value. 63