xref: /OK3568_Linux_fs/kernel/Documentation/hwmon/nct7904.rst (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593SmuzhiyunKernel driver nct7904
2*4882a593Smuzhiyun=====================
3*4882a593Smuzhiyun
4*4882a593SmuzhiyunSupported chip:
5*4882a593Smuzhiyun
6*4882a593Smuzhiyun  * Nuvoton NCT7904D
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8*4882a593Smuzhiyun    Prefix: nct7904
9*4882a593Smuzhiyun
10*4882a593Smuzhiyun    Addresses: I2C 0x2d, 0x2e
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun    Datasheet: Publicly available at Nuvoton website
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14*4882a593Smuzhiyun	http://www.nuvoton.com/
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16*4882a593SmuzhiyunAuthor: Vadim V. Vlasov <vvlasov@dev.rtsoft.ru>
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19*4882a593SmuzhiyunDescription
20*4882a593Smuzhiyun-----------
21*4882a593Smuzhiyun
22*4882a593SmuzhiyunThe NCT7904D is a hardware monitor supporting up to 20 voltage sensors,
23*4882a593Smuzhiyuninternal temperature sensor, Intel PECI and AMD SB-TSI CPU temperature
24*4882a593Smuzhiyuninterface, up to 12 fan tachometer inputs, up to 4 fan control channels
25*4882a593Smuzhiyunwith SmartFan.
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27*4882a593Smuzhiyun
28*4882a593SmuzhiyunSysfs entries
29*4882a593Smuzhiyun-------------
30*4882a593Smuzhiyun
31*4882a593SmuzhiyunCurrently, the driver supports only the following features:
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun======================= =======================================================
34*4882a593Smuzhiyunin[1-20]_input		Input voltage measurements (mV)
35*4882a593Smuzhiyun
36*4882a593Smuzhiyunfan[1-12]_input		Fan tachometer measurements (rpm)
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38*4882a593Smuzhiyuntemp1_input		Local temperature (1/1000 degree,
39*4882a593Smuzhiyun			0.125 degree resolution)
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41*4882a593Smuzhiyuntemp[2-9]_input		CPU temperatures (1/1000 degree,
42*4882a593Smuzhiyun			0.125 degree resolution)
43*4882a593Smuzhiyun
44*4882a593Smuzhiyunpwm[1-4]_enable		R/W, 1/2 for manual or SmartFan mode
45*4882a593Smuzhiyun			Setting SmartFan mode is supported only if it has been
46*4882a593Smuzhiyun			previously configured by BIOS (or configuration EEPROM)
47*4882a593Smuzhiyun
48*4882a593Smuzhiyunpwm[1-4]		R/O in SmartFan mode, R/W in manual control mode
49*4882a593Smuzhiyun======================= =======================================================
50*4882a593Smuzhiyun
51*4882a593SmuzhiyunThe driver checks sensor control registers and does not export the sensors
52*4882a593Smuzhiyunthat are not enabled. Anyway, a sensor that is enabled may actually be not
53*4882a593Smuzhiyunconnected and thus provide zero readings.
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun
56*4882a593SmuzhiyunLimitations
57*4882a593Smuzhiyun-----------
58*4882a593Smuzhiyun
59*4882a593SmuzhiyunThe following features are not supported in current version:
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun - SmartFan control
62*4882a593Smuzhiyun - Watchdog
63*4882a593Smuzhiyun - GPIO
64*4882a593Smuzhiyun - external temperature sensors
65*4882a593Smuzhiyun - SMI
66*4882a593Smuzhiyun - min/max values
67*4882a593Smuzhiyun - many other...
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