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Andrew Jeffery4d420a62017-11-03 15:53:02 +11001Kernel driver max31785
2======================
3
4Supported chips:
Mauro Carvalho Chehab1f234ff2019-04-17 06:46:26 -03005
Andrew Jeffery4d420a62017-11-03 15:53:02 +11006 * Maxim MAX31785, MAX31785A
Mauro Carvalho Chehab1f234ff2019-04-17 06:46:26 -03007
Andrew Jeffery4d420a62017-11-03 15:53:02 +11008 Prefix: 'max31785' or 'max31785a'
Mauro Carvalho Chehab1f234ff2019-04-17 06:46:26 -03009
Andrew Jeffery4d420a62017-11-03 15:53:02 +110010 Addresses scanned: -
Mauro Carvalho Chehab1f234ff2019-04-17 06:46:26 -030011
Andrew Jeffery4d420a62017-11-03 15:53:02 +110012 Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX31785.pdf
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14Author: Andrew Jeffery <andrew@aj.id.au>
15
16Description
17-----------
18
19The Maxim MAX31785 is a PMBus device providing closed-loop, multi-channel fan
20management with temperature and remote voltage sensing. Various fan control
21features are provided, including PWM frequency control, temperature hysteresis,
22dual tachometer measurements, and fan health monitoring.
23
Andrew Jefferycf583b42017-11-20 15:12:06 +103024For dual-rotor configurations the MAX31785A exposes the second rotor tachometer
25readings in attributes fan[5-8]_input. By contrast the MAX31785 only exposes
26the slowest rotor measurement, and does so in the fan[1-4]_input attributes.
Andrew Jeffery4d420a62017-11-03 15:53:02 +110027
28Usage Notes
29-----------
30
31This driver does not probe for PMBus devices. You will have to instantiate
32devices explicitly.
33
34Sysfs attributes
35----------------
36
Mauro Carvalho Chehab1f234ff2019-04-17 06:46:26 -030037======================= =======================================================
Andrew Jeffery4d420a62017-11-03 15:53:02 +110038fan[1-4]_alarm Fan alarm.
39fan[1-4]_fault Fan fault.
Andrew Jefferycf583b42017-11-20 15:12:06 +103040fan[1-8]_input Fan RPM. On the MAX31785A, inputs 5-8 correspond to the
41 second rotor of fans 1-4
Andrew Jeffery56ad86b2017-11-20 15:12:04 +103042fan[1-4]_target Fan input target
Andrew Jeffery4d420a62017-11-03 15:53:02 +110043
44in[1-6]_crit Critical maximum output voltage
45in[1-6]_crit_alarm Output voltage critical high alarm
46in[1-6]_input Measured output voltage
47in[1-6]_label "vout[18-23]"
48in[1-6]_lcrit Critical minimum output voltage
49in[1-6]_lcrit_alarm Output voltage critical low alarm
50in[1-6]_max Maximum output voltage
51in[1-6]_max_alarm Output voltage high alarm
52in[1-6]_min Minimum output voltage
53in[1-6]_min_alarm Output voltage low alarm
54
Andrew Jeffery56ad86b2017-11-20 15:12:04 +103055pwm[1-4] Fan target duty cycle (0..255)
56pwm[1-4]_enable 0: Full-speed
57 1: Manual PWM control
58 2: Automatic PWM (tach-feedback RPM fan-control)
59 3: Automatic closed-loop (temp-feedback fan-control)
60
Andrew Jeffery4d420a62017-11-03 15:53:02 +110061temp[1-11]_crit Critical high temperature
62temp[1-11]_crit_alarm Chip temperature critical high alarm
63temp[1-11]_input Measured temperature
64temp[1-11]_max Maximum temperature
65temp[1-11]_max_alarm Chip temperature high alarm
Mauro Carvalho Chehab1f234ff2019-04-17 06:46:26 -030066======================= =======================================================