1Kernel driver max31790
2======================
3
4Supported chips:
5
6  * Maxim MAX31790
7
8    Prefix: 'max31790'
9
10    Addresses scanned: -
11
12    Datasheet: https://pdfserv.maximintegrated.com/en/ds/MAX31790.pdf
13
14Author: Il Han <corone.il.han@gmail.com>
15
16
17Description
18-----------
19
20This driver implements support for the Maxim MAX31790 chip.
21
22The MAX31790 controls the speeds of up to six fans using six independent
23PWM outputs. The desired fan speeds (or PWM duty cycles) are written
24through the I2C interface. The outputs drive "4-wire" fans directly,
25or can be used to modulate the fan's power terminals using an external
26pass transistor.
27
28Tachometer inputs monitor fan tachometer logic outputs for precise (+/-1%)
29monitoring and control of fan RPM as well as detection of fan failure.
30Six pins are dedicated tachometer inputs. Any of the six PWM outputs can
31also be configured to serve as tachometer inputs.
32
33
34Sysfs entries
35-------------
36
37================== === =======================================================
38fan[1-12]_input    RO  fan tachometer speed in RPM
39fan[1-12]_fault    RO  fan experienced fault
40fan[1-6]_target    RW  desired fan speed in RPM
41fan[1-6]_enable    RW  enable or disable the tachometer input
42pwm[1-6]_enable    RW  regulator mode, 0=disabled (duty cycle=0%), 1=manual mode, 2=rpm mode
43pwm[1-6]           RW  read: current pwm duty cycle,
44                       write: target pwm duty cycle (0-255)
45================== === =======================================================
46