Note
====
-This driver is experimental and has only been tested on NCT6775F.
+This driver supercedes the NCT6775F and NCT6776F support in the W83627EHF
+driver. It supports NCT6775F, NCT6776F, and NCT6779D.
-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.
+Preliminary support for NCT6106D is available in the nct6106 git branch.
+The code in this branch is untested.
-This driver supercedes the NCT6775F and NCT6776F support in the W83627EHF
-driver.
+The driver should be in shape for upstream integration, and has been submitted
+to the lm-sensors mailing list for that purpose. Testing and review feedback
+will be required for the driver to be actually integrated. If you use the latest
+version of this driver, and/or if you can provide review feedback, please let
+the author know.
Kernel driver NCT6775
=======================
Supported chips:
+ * Nuvoton NCT6106
+ 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
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,
+and NCT6779D 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:
+The mode works for fan1-fan5.
-temp1 -> pwm1
-temp2 -> pwm2
-temp3 -> pwm3
-
-/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)
+---------------------
-Implementation Details
-----------------------
+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.
+
+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
+pwm[1-5]_step_enable Set to 1 to enable fine grain speed control.
+ If disabled, pwm values will increase or decrease to
+ the values configured in the auto_point_pwm attributes.
+ If enabled, pwm values will be interpolated, resulting
+ in a more fine-grained fan control, resulting in a more
+ fine-grained fan control
+
+
+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.
projects / groeck-nct6775 / blobdiff