blob: 270c5f865261a030cf026bdde2975f400ce73a65 [file] [log] [blame]
Andrew Jeffery4d420a62017-11-03 15:53:02 +11001Kernel driver max31785
2======================
3
4Supported chips:
5 * Maxim MAX31785, MAX31785A
6 Prefix: 'max31785' or 'max31785a'
7 Addresses scanned: -
8 Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX31785.pdf
9
10Author: Andrew Jeffery <andrew@aj.id.au>
11
12Description
13-----------
14
15The Maxim MAX31785 is a PMBus device providing closed-loop, multi-channel fan
16management with temperature and remote voltage sensing. Various fan control
17features are provided, including PWM frequency control, temperature hysteresis,
18dual tachometer measurements, and fan health monitoring.
19
Andrew Jefferycf583b42017-11-20 15:12:06 +103020For dual-rotor configurations the MAX31785A exposes the second rotor tachometer
21readings in attributes fan[5-8]_input. By contrast the MAX31785 only exposes
22the slowest rotor measurement, and does so in the fan[1-4]_input attributes.
Andrew Jeffery4d420a62017-11-03 15:53:02 +110023
24Usage Notes
25-----------
26
27This driver does not probe for PMBus devices. You will have to instantiate
28devices explicitly.
29
30Sysfs attributes
31----------------
32
33fan[1-4]_alarm Fan alarm.
34fan[1-4]_fault Fan fault.
Andrew Jefferycf583b42017-11-20 15:12:06 +103035fan[1-8]_input Fan RPM. On the MAX31785A, inputs 5-8 correspond to the
36 second rotor of fans 1-4
Andrew Jeffery56ad86b2017-11-20 15:12:04 +103037fan[1-4]_target Fan input target
Andrew Jeffery4d420a62017-11-03 15:53:02 +110038
39in[1-6]_crit Critical maximum output voltage
40in[1-6]_crit_alarm Output voltage critical high alarm
41in[1-6]_input Measured output voltage
42in[1-6]_label "vout[18-23]"
43in[1-6]_lcrit Critical minimum output voltage
44in[1-6]_lcrit_alarm Output voltage critical low alarm
45in[1-6]_max Maximum output voltage
46in[1-6]_max_alarm Output voltage high alarm
47in[1-6]_min Minimum output voltage
48in[1-6]_min_alarm Output voltage low alarm
49
Andrew Jeffery56ad86b2017-11-20 15:12:04 +103050pwm[1-4] Fan target duty cycle (0..255)
51pwm[1-4]_enable 0: Full-speed
52 1: Manual PWM control
53 2: Automatic PWM (tach-feedback RPM fan-control)
54 3: Automatic closed-loop (temp-feedback fan-control)
55
Andrew Jeffery4d420a62017-11-03 15:53:02 +110056temp[1-11]_crit Critical high temperature
57temp[1-11]_crit_alarm Chip temperature critical high alarm
58temp[1-11]_input Measured temperature
59temp[1-11]_max Maximum temperature
60temp[1-11]_max_alarm Chip temperature high alarm