Note
====
-This driver is experimental and has only been tested on NCT6775F.
-
-ABI (sysfs attribute support) is not final and is expected to change
-repeatedly before the driver is stable. Until then, please feel free
-to provide your input.
-
This driver supercedes the NCT6775F and NCT6776F support in the W83627EHF
-driver.
+driver. It supports NCT6106D, NCT6775F, NCT6776F, NCT6779D, NCT6791D, and
+NCT6792D.
+
+The driver is also available in the upstream kernel. This version is maintained
+for backward compatibility with older kernels. I am trying to keep it buildable
+for older kernels, but may miss a problem once in a while. If you have a problem
+compiling this driver with any kernel version 2.6.32 or later, please let me
+know.
Kernel driver NCT6775
=======================
Supported chips:
+ * Nuvoton NCT6102D/NCT6104D/NCT6106D
+ Prefix: 'nct6106'
+ Addresses scanned: ISA address retrieved from Super I/O registers
+ Datasheet: Available from Nuvoton upon request
* Nuvoton NCT6775F/W83667HG-I
Prefix: 'nct6775'
Addresses scanned: ISA address retrieved from Super I/O registers
Addresses scanned: ISA address retrieved from Super I/O registers
Datasheet: Available from Nuvoton upon request
* Nuvoton NCT6779D
- Prefix: 'nct6776'
+ Prefix: 'nct6779'
+ Addresses scanned: ISA address retrieved from Super I/O registers
+ Datasheet: Available from Nuvoton upon request
+ * Nuvoton NCT6791D
+ Prefix: 'nct6791'
+ Addresses scanned: ISA address retrieved from Super I/O registers
+ Datasheet: Available from Nuvoton upon request
+ * Nuvoton NCT6792D
+ Prefix: 'nct6792'
Addresses scanned: ISA address retrieved from Super I/O registers
Datasheet: Available from Nuvoton upon request
Authors:
Guenter Roeck <linux@roeck-us.net>
+ David Bartley <andareed@gmail.com> (NCT6791D support)
Description
-----------
-This driver implements support for the Nuvoton NCT6775F, NCT6776F, and NCT6779D
-super I/O chips. We will refer to them collectively as Nuvoton chips.
+This driver implements support for the Nuvoton NCT6106D, NCT6775F, NCT6776F,
+NCT6779D, NCT6791D, and NCT6792D super I/O chips. We will refer to them
+collectively as Nuvoton chips.
-The chips implement 2 to 4 temperature sensors (9 for NCT6775F and NCT6776F),
-2 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 chips implement up to 8 temperature sensors depending on the chip type and
+configuration. Temperatures used to control fan speed are reported separately.
+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. temp4 and higher
attributes are only reported if its temperature source differs from the
The configured source for each of the temperature sensors is provided
in tempX_label.
-Temperatures are measured in degrees Celsius and measurement resolution is 1
-degC for temp1 and and 0.5 degC for temp2 and temp3. For temp4 and higher,
-resolution is 1 degC for W83667HG-B and 0.5 degC for NCT6775F and NCT6776F.
-An alarm is triggered when the temperature gets higher than high limit;
-it stays on until the temperature falls below the hysteresis value.
-Alarms are only supported for temp1, temp2, and temp3.
+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, temp2, and temp3.
Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
triggered if the rotation speed has dropped below a programmable limit. Fan
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-fan4. Mapping of temperatures to pwm outputs is as
-follows:
-
-temp1 -> pwm1
-temp2 -> pwm2
-temp3 -> pwm3
+The mode works for fan1-fan5.
-/sys files
-----------
+sysfs attributes
+----------------
name - this is a standard hwmon device entry, it contains the name of
the device (see the prefix in the list of supported devices at
* 1 Manual mode, write to pwm file any value 0-255 (full speed)
* 2 "Thermal Cruise" mode
* 3 "Fan Speed Cruise" mode
- * 4 "Smart Fan IV" mode
-
- SmartFan III mode is not supported by the driver.
+ * 4 "Smart Fan III" mode (NCT6775F only)
+ * 5 "Smart Fan IV" mode
pwm[1-5]_mode - controls if output is PWM or DC level
* 0 DC output (0 - 12v)
* 1 PWM output
-Thermal Cruise mode
--------------------
+Common fan control attributes
+-----------------------------
+
+pwm[1-5]_temp_sel Temperature source. Value is temperature sensor index.
+ For example, select '1' for temp1_input.
+pwm[1-5]_weight_temp_sel
+ Secondary temperature source. Value is temperature
+ sensor index. For example, select '1' for temp1_input.
+pwm[1-5]_weight_enable Set to 1 to enable secondary temperature control.
+
+If secondary temperature functionality is enabled, it is controlled with the
+following attributes.
+
+pwm[1-5]_weight_duty_step
+ Duty step size.
+pwm[1-5]_weight_temp_step
+ Temperature step size. With each step over
+ temp_step_base, the value of weight_duty_step is added
+ to the current pwm value.
+pwm[1-5]_weight_temp_step_base
+ Temperature at which secondary temperature control kicks
+ in.
+pwm[1-5]_weight_temp_step_tol
+ Temperature step tolerance or hysteresis. This is a
+ relative value.
+
+
+Thermal Cruise mode (2)
+-----------------------
If the temperature is in the range defined by:
pwm[1-5]_start_output fan pwm start value (range 1 - 255), to start fan
when the temperature is above defined range.
-pwm[1-5]_stop_output fan pwm (range 1 - 255) to stop fan.
+pwm[1-5]_stop_output lowest fan pwm (range 1 - 255) if temperature is below
+ the defined range.
+pwm[1-5]_stop_output_enable
+ Set to 1 to enable pwm[1-5]_stop_output. If disabled
+ (set to 0), the fan will stop if the temperature is
+ below the defined range.
pwm[1-5]_step_up_time milliseconds [ms] before fan speed is increased
pwm[1-5]_step_down_time milliseconds [ms] before fan speed is decreased
pwm[1-5]_stop_time how many milliseconds [ms] must elapse to switch
- corresponding fan off. (when the temperature was below
+ corresponding fan off (when the temperature was below
defined range).
-Speed Cruise mode
------------------
+Speed Cruise mode (3)
+---------------------
This modes tries to keep the fan speed constant.
Untested; use at your own risk.
-Support may be removed in a later version of the driver.
+Smart Fan IV mode (5)
+---------------------
+
+The fan is regulated to maintain a target temperature. There are five data
+points. Subsequent data points should be set to higher temperatures and higher
+pwm values to achieve higher fan speeds with increasing temperature. The last
+data point reflects critical temperature mode, in which the fans should run at
+full speed.
-Implementation Details
-----------------------
+pwm[1-5]_auto_point[1-5]_pwm
+ pwm value to be set if temperature reaches matching
+ temperature range.
+pwm[1-5]_auto_point[1-5]_temp
+ Temperature at which the matching pwm is enabled.
+pwm[1-5]_step_up_time milliseconds [ms] before fan speed is increased
+pwm[1-5]_step_down_time milliseconds [ms] before fan speed is decreased
+
+
+Usage Notes
+-----------
-TBD
+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.
+
+Also, there have been reports that not all fan speeds are reported on at least
+some ASUS boards. P9X79 WS is one example, where fan speed is only reported
+for two of the fans on the board.
+
+Note that ASUS does not support Linux on desktop boards (this appears to be
+official ASUS policy) and does not release board specifications, so there is
+nothing we can do to improve support for such boards unless we get board
+specifications or a detailed description on how to control the fans on the
+affected boards.
+
+Known Problems
+--------------
+
+After a suspend/resume cycle, all fan control settings are restored to the BIOS
+defaults.
projects / groeck-nct6775 / blobdiff