1*4882a593SmuzhiyunKernel driver max31790 2*4882a593Smuzhiyun====================== 3*4882a593Smuzhiyun 4*4882a593SmuzhiyunSupported chips: 5*4882a593Smuzhiyun 6*4882a593Smuzhiyun * Maxim MAX31790 7*4882a593Smuzhiyun 8*4882a593Smuzhiyun Prefix: 'max31790' 9*4882a593Smuzhiyun 10*4882a593Smuzhiyun Addresses scanned: - 11*4882a593Smuzhiyun 12*4882a593Smuzhiyun Datasheet: https://pdfserv.maximintegrated.com/en/ds/MAX31790.pdf 13*4882a593Smuzhiyun 14*4882a593SmuzhiyunAuthor: Il Han <corone.il.han@gmail.com> 15*4882a593Smuzhiyun 16*4882a593Smuzhiyun 17*4882a593SmuzhiyunDescription 18*4882a593Smuzhiyun----------- 19*4882a593Smuzhiyun 20*4882a593SmuzhiyunThis driver implements support for the Maxim MAX31790 chip. 21*4882a593Smuzhiyun 22*4882a593SmuzhiyunThe MAX31790 controls the speeds of up to six fans using six independent 23*4882a593SmuzhiyunPWM outputs. The desired fan speeds (or PWM duty cycles) are written 24*4882a593Smuzhiyunthrough the I2C interface. The outputs drive "4-wire" fans directly, 25*4882a593Smuzhiyunor can be used to modulate the fan's power terminals using an external 26*4882a593Smuzhiyunpass transistor. 27*4882a593Smuzhiyun 28*4882a593SmuzhiyunTachometer inputs monitor fan tachometer logic outputs for precise (+/-1%) 29*4882a593Smuzhiyunmonitoring and control of fan RPM as well as detection of fan failure. 30*4882a593SmuzhiyunSix pins are dedicated tachometer inputs. Any of the six PWM outputs can 31*4882a593Smuzhiyunalso be configured to serve as tachometer inputs. 32*4882a593Smuzhiyun 33*4882a593Smuzhiyun 34*4882a593SmuzhiyunSysfs entries 35*4882a593Smuzhiyun------------- 36*4882a593Smuzhiyun 37*4882a593Smuzhiyun================== === ======================================================= 38*4882a593Smuzhiyunfan[1-12]_input RO fan tachometer speed in RPM 39*4882a593Smuzhiyunfan[1-12]_fault RO fan experienced fault 40*4882a593Smuzhiyunfan[1-6]_target RW desired fan speed in RPM 41*4882a593Smuzhiyunpwm[1-6]_enable RW regulator mode, 0=disabled (duty cycle=0%), 1=manual mode, 2=rpm mode 42*4882a593Smuzhiyunpwm[1-6] RW read: current pwm duty cycle, 43*4882a593Smuzhiyun write: target pwm duty cycle (0-255) 44*4882a593Smuzhiyun================== === ======================================================= 45