Documentation/hwmon/w83792d - kernel/common - Git at Google

 Kernel driver w83792d
 =====================

 Supported chips:
   * Winbond W83792D
     Prefix: 'w83792d'
     Addresses scanned: I2C 0x2c - 0x2f
     Datasheet: http://www.winbond.com.tw

 Author: Shane Huang (Winbond)
 Updated: Roger Lucas


 Module Parameters
 -----------------

 * init int
   (default 1)
   Use 'init=0' to bypass initializing the chip.
   Try this if your computer crashes when you load the module.

 * force_subclients=bus,caddr,saddr,saddr
   This is used to force the i2c addresses for subclients of
   a certain chip. Example usage is `force_subclients=0,0x2f,0x4a,0x4b'
   to force the subclients of chip 0x2f on bus 0 to i2c addresses
   0x4a and 0x4b.


 Description
 -----------

 This driver implements support for the Winbond W83792AD/D.

 Detection of the chip can sometimes be foiled because it can be in an
 internal state that allows no clean access (Bank with ID register is not
 currently selected). If you know the address of the chip, use a 'force'
 parameter; this will put it into a more well-behaved state first.

 The driver implements three temperature sensors, seven fan rotation speed
 sensors, nine voltage sensors, and two automatic fan regulation
 strategies called: Smart Fan I (Thermal Cruise mode) and Smart Fan II.

 The driver also implements up to seven fan control outputs: pwm1-7.  Pwm1-7
 can be configured to PWM output or Analogue DC output via their associated
 pwmX_mode. Outputs pwm4 through pwm7 may or may not be present depending on
 how the W83792AD/D was configured by the BIOS.

 Automatic fan control mode is possible only for fan1-fan3.

 For all pwmX outputs, a value of 0 means minimum fan speed and a value of
 255 means maximum fan speed.

 Temperatures are measured in degrees Celsius and measurement resolution is 1
 degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when
 the temperature gets higher than the Overtemperature Shutdown value; it stays
 on until the temperature falls below the Hysteresis value.

 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
 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.

 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.

 Alarms are provided as output from "realtime status register". Following bits
 are defined:

 bit - alarm on:
 0  - in0
 1  - in1
 2  - temp1
 3  - temp2
 4  - temp3
 5  - fan1
 6  - fan2
 7  - fan3
 8  - in2
 9  - in3
 10 - in4
 11 - in5
 12 - in6
 13 - VID change
 14 - chassis
 15 - fan7
 16 - tart1
 17 - tart2
 18 - tart3
 19 - in7
 20 - in8
 21 - fan4
 22 - fan5
 23 - fan6

 Tart will be asserted while target temperature cannot be achieved after 3 minutes
 of full speed rotation of corresponding fan.

 In addition to the alarms described above, there is a CHAS alarm on the chips
 which triggers if your computer case is open (This one is latched, contrary
 to realtime alarms).

 The chips only update values each 3 seconds; reading them more often will
 do no harm, but will return 'old' values.


 W83792D PROBLEMS
 ----------------
 Known problems:
 	- This driver is only for Winbond W83792D C version device, there
 	  are also some motherboards with B version W83792D device. The
 	  calculation method to in6-in7(measured value, limits) is a little
 	  different between C and B version. C or B version can be identified
 	  by CR[0x49h].
 	- The function of vid and vrm has not been finished, because I'm NOT
 	  very familiar with them. Adding support is welcome.
  	- The function of chassis open detection needs more tests.
 	- If you have ASUS server board and chip was not found: Then you will
 	  need to upgrade to latest (or beta) BIOS. If it does not help please
 	  contact us.

 Fan control
 -----------

 Manual mode
 -----------

 Works as expected. You just need to specify desired PWM/DC value (fan speed)
 in appropriate pwm# file.

 Thermal cruise
 --------------

 In this mode, W83792D provides the Smart Fan system to automatically control
 fan speed to keep the temperatures of CPU and the system within specific
 range. At first a wanted temperature and interval must be set. This is done
 via thermal_cruise# file. The tolerance# file serves to create T +- tolerance
 interval. The fan speed will be lowered as long as the current temperature
 remains below the thermal_cruise# +- tolerance# value. Once the temperature
 exceeds the high limit (T+tolerance), the fan will be turned on with a
 specific speed set by pwm# and automatically controlled its PWM duty cycle
 with the temperature varying. Three conditions may occur:

 (1) If the temperature still exceeds the high limit, PWM duty
 cycle will increase slowly.

 (2) If the temperature goes below the high limit, but still above the low
 limit (T-tolerance), the fan speed will be fixed at the current speed because
 the temperature is in the target range.

 (3) If the temperature goes below the low limit, PWM duty cycle will decrease
 slowly to 0 or a preset stop value until the temperature exceeds the low
 limit. (The preset stop value handling is not yet implemented in driver)

 Smart Fan II
 ------------

 W83792D also provides a special mode for fan. Four temperature points are
 available. When related temperature sensors detects the temperature in preset
 temperature region (sf2_point@_fan# +- tolerance#) it will cause fans to run
 on programmed value from sf2_level@_fan#. You need to set four temperatures
 for each fan.


 /sys files
 ----------

 pwm[1-7] - this file stores PWM duty cycle or DC value (fan speed) in range:
 	0 (stop) to 255 (full)
 pwm[1-3]_enable - this file controls mode of fan/temperature control:
             * 0 Disabled
             * 1 Manual mode
             * 2 Smart Fan II
             * 3 Thermal Cruise
 pwm[1-7]_mode - Select PWM or DC mode
             * 0 DC
             * 1 PWM
 thermal_cruise[1-3] - Selects the desired temperature for cruise (degC)
 tolerance[1-3] - Value in degrees of Celsius (degC) for +- T
 sf2_point[1-4]_fan[1-3] - four temperature points for each fan for Smart Fan II
 sf2_level[1-3]_fan[1-3] - three PWM/DC levels for each fan for Smart Fan II
	Kernel driver w83792d
	=====================

	Supported chips:
	* Winbond W83792D
	Prefix: 'w83792d'
	Addresses scanned: I2C 0x2c - 0x2f
	Datasheet: http://www.winbond.com.tw

	Author: Shane Huang (Winbond)
	Updated: Roger Lucas


	Module Parameters
	-----------------

	* init int
	(default 1)
	Use 'init=0' to bypass initializing the chip.
	Try this if your computer crashes when you load the module.

	* force_subclients=bus,caddr,saddr,saddr
	This is used to force the i2c addresses for subclients of
	a certain chip. Example usage is `force_subclients=0,0x2f,0x4a,0x4b'
	to force the subclients of chip 0x2f on bus 0 to i2c addresses
	0x4a and 0x4b.


	Description
	-----------

	This driver implements support for the Winbond W83792AD/D.

	Detection of the chip can sometimes be foiled because it can be in an
	internal state that allows no clean access (Bank with ID register is not
	currently selected). If you know the address of the chip, use a 'force'
	parameter; this will put it into a more well-behaved state first.

	The driver implements three temperature sensors, seven fan rotation speed
	sensors, nine voltage sensors, and two automatic fan regulation
	strategies called: Smart Fan I (Thermal Cruise mode) and Smart Fan II.

	The driver also implements up to seven fan control outputs: pwm1-7. Pwm1-7
	can be configured to PWM output or Analogue DC output via their associated
	pwmX_mode. Outputs pwm4 through pwm7 may or may not be present depending on
	how the W83792AD/D was configured by the BIOS.

	Automatic fan control mode is possible only for fan1-fan3.

	For all pwmX outputs, a value of 0 means minimum fan speed and a value of
	255 means maximum fan speed.

	Temperatures are measured in degrees Celsius and measurement resolution is 1
	degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when
	the temperature gets higher than the Overtemperature Shutdown value; it stays
	on until the temperature falls below the Hysteresis value.

	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
	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.

	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.

	Alarms are provided as output from "realtime status register". Following bits
	are defined:

	bit - alarm on:
	0 - in0
	1 - in1
	2 - temp1
	3 - temp2
	4 - temp3
	5 - fan1
	6 - fan2
	7 - fan3
	8 - in2
	9 - in3
	10 - in4
	11 - in5
	12 - in6
	13 - VID change
	14 - chassis
	15 - fan7
	16 - tart1
	17 - tart2
	18 - tart3
	19 - in7
	20 - in8
	21 - fan4
	22 - fan5
	23 - fan6

	Tart will be asserted while target temperature cannot be achieved after 3 minutes
	of full speed rotation of corresponding fan.

	In addition to the alarms described above, there is a CHAS alarm on the chips
	which triggers if your computer case is open (This one is latched, contrary
	to realtime alarms).

	The chips only update values each 3 seconds; reading them more often will
	do no harm, but will return 'old' values.


	W83792D PROBLEMS
	----------------
	Known problems:
	- This driver is only for Winbond W83792D C version device, there
	are also some motherboards with B version W83792D device. The
	calculation method to in6-in7(measured value, limits) is a little
	different between C and B version. C or B version can be identified
	by CR[0x49h].
	- The function of vid and vrm has not been finished, because I'm NOT
	very familiar with them. Adding support is welcome.
	- The function of chassis open detection needs more tests.
	- If you have ASUS server board and chip was not found: Then you will
	need to upgrade to latest (or beta) BIOS. If it does not help please
	contact us.

	Fan control
	-----------

	Manual mode
	-----------

	Works as expected. You just need to specify desired PWM/DC value (fan speed)
	in appropriate pwm# file.

	Thermal cruise
	--------------

	In this mode, W83792D provides the Smart Fan system to automatically control
	fan speed to keep the temperatures of CPU and the system within specific
	range. At first a wanted temperature and interval must be set. This is done
	via thermal_cruise# file. The tolerance# file serves to create T +- tolerance
	interval. The fan speed will be lowered as long as the current temperature
	remains below the thermal_cruise# +- tolerance# value. Once the temperature
	exceeds the high limit (T+tolerance), the fan will be turned on with a
	specific speed set by pwm# and automatically controlled its PWM duty cycle
	with the temperature varying. Three conditions may occur:

	(1) If the temperature still exceeds the high limit, PWM duty
	cycle will increase slowly.

	(2) If the temperature goes below the high limit, but still above the low
	limit (T-tolerance), the fan speed will be fixed at the current speed because
	the temperature is in the target range.

	(3) If the temperature goes below the low limit, PWM duty cycle will decrease
	slowly to 0 or a preset stop value until the temperature exceeds the low
	limit. (The preset stop value handling is not yet implemented in driver)

	Smart Fan II
	------------

	W83792D also provides a special mode for fan. Four temperature points are
	available. When related temperature sensors detects the temperature in preset
	temperature region (sf2_point@_fan# +- tolerance#) it will cause fans to run
	on programmed value from sf2_level@_fan#. You need to set four temperatures
	for each fan.


	/sys files
	----------

	pwm[1-7] - this file stores PWM duty cycle or DC value (fan speed) in range:
	0 (stop) to 255 (full)
	pwm[1-3]_enable - this file controls mode of fan/temperature control:
	* 0 Disabled
	* 1 Manual mode
	* 2 Smart Fan II
	* 3 Thermal Cruise
	pwm[1-7]_mode - Select PWM or DC mode
	* 0 DC
	* 1 PWM
	thermal_cruise[1-3] - Selects the desired temperature for cruise (degC)
	tolerance[1-3] - Value in degrees of Celsius (degC) for +- T
	sf2_point[1-4]_fan[1-3] - four temperature points for each fan for Smart Fan II
	sf2_level[1-3]_fan[1-3] - three PWM/DC levels for each fan for Smart Fan II