1 files changed, 67 insertions, 0 deletions
diff --git a/Documentation/hwmon/nct7904.rst b/Documentation/hwmon/nct7904.rst
new file mode 100644
index 000000000000..5b2f111582ff
--- /dev/null
+++ b/Documentation/hwmon/nct7904.rst
@@ -0,0 +1,67 @@
+Kernel driver nct7904
+=====================
+
+Supported chip:
+
+  * Nuvoton NCT7904D
+
+    Prefix: nct7904
+
+    Addresses: I2C 0x2d, 0x2e
+
+    Datasheet: Publicly available at Nuvoton website
+
+	http://www.nuvoton.com/
+
+Author: Vadim V. Vlasov <vvlasov@dev.rtsoft.ru>
+
+
+Description
+-----------
+
+The NCT7904D is a hardware monitor supporting up to 20 voltage sensors,
+internal temperature sensor, Intel PECI and AMD SB-TSI CPU temperature
+interface, up to 12 fan tachometer inputs, up to 4 fan control channels
+with SmartFan.
+
+
+Sysfs entries
+-------------
+
+Currently, the driver supports only the following features:
+
+======================= =======================================================
+in[1-20]_input		Input voltage measurements (mV)
+
+fan[1-12]_input		Fan tachometer measurements (rpm)
+
+temp1_input		Local temperature (1/1000 degree,
+			0.125 degree resolution)
+
+temp[2-9]_input		CPU temperatures (1/1000 degree,
+			0.125 degree resolution)
+
+pwm[1-4]_enable		R/W, 1/2 for manual or SmartFan mode
+			Setting SmartFan mode is supported only if it has been
+			previously configured by BIOS (or configuration EEPROM)
+
+pwm[1-4]		R/O in SmartFan mode, R/W in manual control mode
+======================= =======================================================
+
+The driver checks sensor control registers and does not export the sensors
+that are not enabled. Anyway, a sensor that is enabled may actually be not
+connected and thus provide zero readings.
+
+
+Limitations
+-----------
+
+The following features are not supported in current version:
+
+ - SmartFan control
+ - Watchdog
+ - GPIO
+ - external temperature sensors
+ - SMI
+ - min/max values
+ - many other...