Commit 9de2e2e8 authored by Guenter Roeck's avatar Guenter Roeck
Browse files

hwmon: Driver for Nuvoton NCT6775F, NCT6776F, and NCT6779D 



This driver will replace the w83627ehf driver for NCT6775F and NCT6776F,
and provides support for NCT6779D.

This patch provides support for voltage monitor attributes.

Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent 24f9c539

Documentation/hwmon/nct6775

0 → 100644
+81 −0
Original line number Diff line number Diff line 
Note

====



This driver supersedes the NCT6775F and NCT6776F support in the W83627EHF

driver.



Kernel driver NCT6775

=====================



Supported chips:

  * Nuvoton NCT6775F/W83667HG-I

    Prefix: 'nct6775'

    Addresses scanned: ISA address retrieved from Super I/O registers

    Datasheet: Available from Nuvoton upon request

  * Nuvoton NCT6776F

    Prefix: 'nct6776'

    Addresses scanned: ISA address retrieved from Super I/O registers

    Datasheet: Available from Nuvoton upon request

  * Nuvoton NCT6779D

    Prefix: 'nct6779'

    Addresses scanned: ISA address retrieved from Super I/O registers

    Datasheet: Available from Nuvoton upon request



Authors:

        Guenter Roeck <linux@roeck-us.net>



Description

-----------



This driver implements support for the Nuvoton NCT6775F, NCT6776F, and NCT6779D

super I/O chips.



The chips support up to 25 temperature monitoring sources. Up to 6 of those are

direct temperature sensor inputs, the others are special sources such as PECI,

PCH, and SMBUS. Depending on the chip type, 2 to 6 of the temperature sources

can be monitored and compared against minimum, maximum, and critical

temperatures. The driver reports up to 10 of the temperatures to the user.

There are 4 to 5 fan rotation speed sensors, 8 to 15 analog voltage sensors,

one VID, alarms with beep warnings (control unimplemented), and some automatic

fan regulation strategies (plus manual fan control mode).



The temperature sensor sources on all chips are configurable. The configured

source for each of the temperature sensors is provided in tempX_label.



Temperatures are measured in degrees Celsius and measurement resolution is

either 1 degC or 0.5 degC, depending on the temperature source and

configuration. An alarm is triggered when the temperature gets higher than

the high limit; it stays on until the temperature falls below the hysteresis

value. Alarms are only supported for temp1 to temp6, depending on the chip type.



Fan rotation speeds are reported in RPM (rotations per minute). An alarm is

triggered if the rotation speed has dropped below a programmable limit. On

NCT6775F, fan readings can be divided by a programmable divider (1, 2, 4, 8,

16, 32, 64 or 128) to give the readings more range or accuracy; the other chips

do not have a fan speed divider. The driver sets the most suitable fan divisor

itself; specifically, it doubles the divider value each time a fan speed reading

returns an invalid value. Some fans might not be present because they share pins

with other functions.



Voltage sensors (also known as IN sensors) report their values in millivolts.

An alarm is triggered if the voltage has crossed a programmable minimum

or maximum limit.



The driver supports automatic fan control mode known as Thermal Cruise.

In this mode, the chip attempts to keep the measured temperature in a

predefined temperature range. If the temperature goes out of range, fan

is driven slower/faster to reach the predefined range again.



The mode works for fan1-fan5.



Usage Notes

-----------



On various ASUS boards with NCT6776F, it appears that CPUTIN is not really

connected to anything and floats, or that it is connected to some non-standard

temperature measurement device. As a result, the temperature reported on CPUTIN

will not reflect a usable value. It often reports unreasonably high

temperatures, and in some cases the reported temperature declines if the actual

temperature increases (similar to the raw PECI temperature value - see PECI

specification for details). CPUTIN should therefore be be ignored on ASUS

boards. The CPU temperature on ASUS boards is reported from PECI 0.

drivers/hwmon/Kconfig

+13 −0
Original line number Diff line number Diff line
@@ -897,6 +897,19 @@ config SENSORS_MCP3021 
	  This driver can also be built as a module.  If so, the module

	  will be called mcp3021.



config SENSORS_NCT6775

	tristate "Nuvoton NCT6775F, NCT6776F, NCT6779D"

	depends on !PPC

	select HWMON_VID

	help

	  If you say yes here you get support for the hardware monitoring

	  functionality of the Nuvoton NCT6775F, NCT6776F, and NCT6779D

	  Super-I/O chips. This driver replaces the w83627ehf driver for

	  NCT6775F and NCT6776F.



	  This driver can also be built as a module.  If so, the module

	  will be called nct6775.



config SENSORS_NTC_THERMISTOR

	tristate "NTC thermistor support"

	depends on (!OF && !IIO) || (OF && IIO)

drivers/hwmon/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -105,6 +105,7 @@ obj-$(CONFIG_SENSORS_MAX6650) += max6650.o 
obj-$(CONFIG_SENSORS_MAX6697)	+= max6697.o

obj-$(CONFIG_SENSORS_MC13783_ADC)+= mc13783-adc.o

obj-$(CONFIG_SENSORS_MCP3021)	+= mcp3021.o

obj-$(CONFIG_SENSORS_NCT6775)	+= nct6775.o

obj-$(CONFIG_SENSORS_NTC_THERMISTOR)	+= ntc_thermistor.o

obj-$(CONFIG_SENSORS_PC87360)	+= pc87360.o

obj-$(CONFIG_SENSORS_PC87427)	+= pc87427.o

drivers/hwmon/nct6775.c

0 → 100644
+1021 −0

File added.

Preview size limit exceeded, changes collapsed.