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1.. SPDX-License-Identifier: GPL-2.0-or-later2 3Kernel driver max317604======================5 6Supported chips:7 * Analog Devices MAX317608 9 Prefix: 'max31760'10 11 Addresses scanned: none12 13 Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX31760.pdf14 15 16Author: Ibrahim Tilki <Ibrahim.Tilki@analog.com>17 18Description19-----------20 21The MAX31760 integrates temperature sensing along with precision PWM fan22control. It accurately measures its local die temperature and the remote23temperature of a discrete diode-connected transistor, such as a 2N3906,24or a thermal diode commonly found on CPUs, graphics processor units (GPUs),25and other ASICs. Multiple temperature thresholds, such as local26high/overtemperature (OT) and remote high/overtemperature, can be set by an27I2C-compatible interface. Fan speed is controlled based on the temperature28reading as an index to a 48-byte lookup table (LUT) containing29user-programmed PWM values. The flexible LUT-based architecture enables30the user to program a smooth nonlinear fan speed vs. temperature transfer31function to minimize acoustic fan noise. Two tachometer inputs allow32measuring the speeds of two fans independently. When the local or remote33OT threshold is exceeded, the SHDN pin is asserted low and can be used to34shut down the system. A dedicated ALERT pin reports that either a local or35remote high-temperature threshold has been exceeded.36 37Temperature measurement range: from -55°C to 125°C38 39Temperature Resolution: 11 Bits, ±0.125°C40 41Please refer how to instantiate this driver: Documentation/i2c/instantiating-devices.rst42 43Lookup table for auto fan control44---------------------------------45 46========= =================================47LUT Index Name48========= =================================491 PWM value for T < +18°C502 PWM value for +18°C ≤ T < +20°C513 PWM value for +20°C ≤ T < +22°C52... ...5347 PWM value for +108°C ≤ T < +110°C5448 PWM value for T ≥ +110°C55========= =================================56 57Sysfs entries58-------------59 60=============================== =================================================================================61fan[1-2]_input Fan speed (in RPM)62fan[1-2]_enable Enable fan readings and fan fault alarms63fan[1-2]_fault Fan fault status64temp[1-2]_label "Remote" and "Local" temperature channel labels65temp[1-2]_input Temperature sensor readings (in millidegrees Celsius)66temp1_fault Remote temperature sensor fault status67temp[1-2]_max Temperature max value. Asserts "ALERT" pin when exceeded68temp[1-2]_max_alarm Temperature max alarm status69temp[1-2]_crit Temperature critical value. Asserts "SHDN" pin when exceeded70temp[1-2]_crit_alarm Temperature critical alarm status71pwm1 PWM value for direct fan control72pwm1_enable 1: direct fan control, 2: temperature based auto fan control73pwm1_freq PWM frequency in hertz74pwm1_auto_channels_temp Temperature source for auto fan control. 1: temp1, 2: temp2, 3: max(temp1, temp2)75pwm1_auto_point[1-48]_pwm PWM value for LUT point76pwm1_auto_point_temp_hyst Temperature hysteresis for auto fan control. Can be either 2000mC or 4000mC77=============================== =================================================================================78