xref: /OK3568_Linux_fs/kernel/Documentation/hwmon/max31785.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunKernel driver max31785
2*4882a593Smuzhiyun======================
3*4882a593Smuzhiyun
4*4882a593SmuzhiyunSupported chips:
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun  * Maxim MAX31785, MAX31785A
7*4882a593Smuzhiyun
8*4882a593Smuzhiyun    Prefix: 'max31785' or 'max31785a'
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun    Addresses scanned: -
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun    Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX31785.pdf
13*4882a593Smuzhiyun
14*4882a593SmuzhiyunAuthor: Andrew Jeffery <andrew@aj.id.au>
15*4882a593Smuzhiyun
16*4882a593SmuzhiyunDescription
17*4882a593Smuzhiyun-----------
18*4882a593Smuzhiyun
19*4882a593SmuzhiyunThe Maxim MAX31785 is a PMBus device providing closed-loop, multi-channel fan
20*4882a593Smuzhiyunmanagement with temperature and remote voltage sensing. Various fan control
21*4882a593Smuzhiyunfeatures are provided, including PWM frequency control, temperature hysteresis,
22*4882a593Smuzhiyundual tachometer measurements, and fan health monitoring.
23*4882a593Smuzhiyun
24*4882a593SmuzhiyunFor dual-rotor configurations the MAX31785A exposes the second rotor tachometer
25*4882a593Smuzhiyunreadings in attributes fan[5-8]_input. By contrast the MAX31785 only exposes
26*4882a593Smuzhiyunthe slowest rotor measurement, and does so in the fan[1-4]_input attributes.
27*4882a593Smuzhiyun
28*4882a593SmuzhiyunUsage Notes
29*4882a593Smuzhiyun-----------
30*4882a593Smuzhiyun
31*4882a593SmuzhiyunThis driver does not probe for PMBus devices. You will have to instantiate
32*4882a593Smuzhiyundevices explicitly.
33*4882a593Smuzhiyun
34*4882a593SmuzhiyunSysfs attributes
35*4882a593Smuzhiyun----------------
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun======================= =======================================================
38*4882a593Smuzhiyunfan[1-4]_alarm		Fan alarm.
39*4882a593Smuzhiyunfan[1-4]_fault		Fan fault.
40*4882a593Smuzhiyunfan[1-8]_input		Fan RPM. On the MAX31785A, inputs 5-8 correspond to the
41*4882a593Smuzhiyun			second rotor of fans 1-4
42*4882a593Smuzhiyunfan[1-4]_target		Fan input target
43*4882a593Smuzhiyun
44*4882a593Smuzhiyunin[1-6]_crit		Critical maximum output voltage
45*4882a593Smuzhiyunin[1-6]_crit_alarm	Output voltage critical high alarm
46*4882a593Smuzhiyunin[1-6]_input		Measured output voltage
47*4882a593Smuzhiyunin[1-6]_label		"vout[18-23]"
48*4882a593Smuzhiyunin[1-6]_lcrit		Critical minimum output voltage
49*4882a593Smuzhiyunin[1-6]_lcrit_alarm	Output voltage critical low alarm
50*4882a593Smuzhiyunin[1-6]_max		Maximum output voltage
51*4882a593Smuzhiyunin[1-6]_max_alarm	Output voltage high alarm
52*4882a593Smuzhiyunin[1-6]_min		Minimum output voltage
53*4882a593Smuzhiyunin[1-6]_min_alarm	Output voltage low alarm
54*4882a593Smuzhiyun
55*4882a593Smuzhiyunpwm[1-4]		Fan target duty cycle (0..255)
56*4882a593Smuzhiyunpwm[1-4]_enable		0: Full-speed
57*4882a593Smuzhiyun			1: Manual PWM control
58*4882a593Smuzhiyun			2: Automatic PWM (tach-feedback RPM fan-control)
59*4882a593Smuzhiyun			3: Automatic closed-loop (temp-feedback fan-control)
60*4882a593Smuzhiyun
61*4882a593Smuzhiyuntemp[1-11]_crit		Critical high temperature
62*4882a593Smuzhiyuntemp[1-11]_crit_alarm	Chip temperature critical high alarm
63*4882a593Smuzhiyuntemp[1-11]_input	Measured temperature
64*4882a593Smuzhiyuntemp[1-11]_max		Maximum temperature
65*4882a593Smuzhiyuntemp[1-11]_max_alarm	Chip temperature high alarm
66*4882a593Smuzhiyun======================= =======================================================
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