hwmon: Driver for Andigilog aSC7621 family monitoring chips

Kernel driver asc7621

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

Supported chips:

    Andigilog aSC7621 and aSC7621a

    Prefix: 'asc7621'

    Addresses scanned: I2C 0x2c, 0x2d, 0x2e

    Datasheet: http://www.fairview5.com/linux/asc7621/asc7621.pdf

Author:

		George Joseph

Description provided by Dave Pivin @ Andigilog:

Andigilog has both the PECI and pre-PECI versions of the Heceta-6, as

Intel calls them. Heceta-6e has high frequency PWM and Heceta-6p has

added PECI and a 4th thermal zone. The Andigilog aSC7611 is the

Heceta-6e part and aSC7621 is the Heceta-6p part. They are both in

volume production, shipping to Intel and their subs.

We have enhanced both parts relative to the governing Intel

specification. First enhancement is temperature reading resolution. We

have used registers below 20h for vendor-specific functions in addition

to those in the Intel-specified vendor range.

Our conversion process produces a result that is reported as two bytes.

The fan speed control uses this finer value to produce a "step-less" fan

PWM output. These two bytes are "read-locked" to guarantee that once a

high or low byte is read, the other byte is locked-in until after the

next read of any register. So to get an atomic reading, read high or low

byte, then the very next read should be the opposite byte. Our data

sheet says 10-bits of resolution, although you may find the lower bits

are active, they are not necessarily reliable or useful externally. We

chose not to mask them.

We employ significant filtering that is user tunable as described in the

data sheet. Our temperature reports and fan PWM outputs are very smooth

when compared to the competition, in addition to the higher resolution

temperature reports. The smoother PWM output does not require user

intervention.

We offer GPIO features on the former VID pins. These are open-drain

outputs or inputs and may be used as general purpose I/O or as alarm

outputs that are based on temperature limits. These are in 19h and 1Ah.

We offer flexible mapping of temperature readings to thermal zones. Any

temperature may be mapped to any zone, which has a default assignment

that follows Intel's specs.

Since there is a fan to zone assignment that allows for the "hotter" of

a set of zones to control the PWM of an individual fan, but there is no

indication to the user, we have added an indicator that shows which zone

is currently controlling the PWM for a given fan. This is in register

00h.

Both remote diode temperature readings may be given an offset value such

that the reported reading as well as the temperature used to determine

PWM may be offset for system calibration purposes.

PECI Extended configuration allows for having more than two domains per

PECI address and also provides an enabling function for each PECI

address. One could use our flexible zone assignment to have a zone

assigned to up to 4 PECI addresses. This is not possible in the default

Intel configuration. This would be useful in multi-CPU systems with

individual fans on each that would benefit from individual fan control.

This is in register 0Eh.

The tachometer measurement system is flexible and able to adapt to many

fan types. We can also support pulse-stretched PWM so that 3-wire fans

may be used. These characteristics are in registers 04h to 07h.

Finally, we have added a tach disable function that turns off the tach

measurement system for individual tachs in order to save power. That is

in register 75h.

--

aSC7621 Product Description

The aSC7621 has a two wire digital interface compatible with SMBus 2.0.

Using a 10-bit ADC, the aSC7621 measures the temperature of two remote diode

connected transistors as well as its own die. Support for Platform

Environmental Control Interface (PECI) is included.

Using temperature information from these four zones, an automatic fan speed

control algorithm is employed to minimize acoustic impact while achieving

recommended CPU temperature under varying operational loads.

To set fan speed, the aSC7621 has three independent pulse width modulation

(PWM) outputs that are controlled by one, or a combination of three,

temperature zones. Both high- and low-frequency PWM ranges are supported.

The aSC7621 also includes a digital filter that can be invoked to smooth

temperature readings for better control of fan speed and minimum acoustic

impact.

The aSC7621 has tachometer inputs to measure fan speed on up to four fans.

Limit and status registers for all measured values are included to alert

the system host that any measurements are outside of programmed limits

via status registers.

System voltages of VCCP, 2.5V, 3.3V, 5.0V, and 12V motherboard power are

monitored efficiently with internal scaling resistors.

Features

- Supports PECI interface and monitors internal and remote thermal diodes

- 2-wire, SMBus 2.0 compliant, serial interface

- 10-bit ADC

- Monitors VCCP, 2.5V, 3.3V, 5.0V, and 12V motherboard/processor supplies

- Programmable autonomous fan control based on temperature readings

- Noise filtering of temperature reading for fan speed control

- 0.25C digital temperature sensor resolution

- 3 PWM fan speed control outputs for 2-, 3- or 4-wire fans and up to 4 fan

	tachometer inputs

- Enhanced measured temperature to Temperature Zone assignment.

- Provides high and low PWM frequency ranges

- 3 GPIO pins for custom use

- 24-Lead QSOP package

Configuration Notes

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

Except where noted below, the sysfs entries created by this driver follow

the standards defined in "sysfs-interface".

temp1_source

	0 	(default) peci_legacy = 0, Remote 1 Temperature

			peci_legacy = 1, PECI Processor Temperature 0

	1 	Remote 1 Temperature

	2 	Remote 2 Temperature

	3 	Internal Temperature

	4 	PECI Processor Temperature 0

	5 	PECI Processor Temperature 1

	6 	PECI Processor Temperature 2

	7  PECI Processor Temperature 3

temp2_source

	0 	(default) Internal Temperature

	1 	Remote 1 Temperature

	2 	Remote 2 Temperature

	3 	Internal Temperature

	4 	PECI Processor Temperature 0

	5 	PECI Processor Temperature 1

	6 	PECI Processor Temperature 2

	7 	PECI Processor Temperature 3

temp3_source

	0 	(default) Remote 2 Temperature

	1 	Remote 1 Temperature

	2 	Remote 2 Temperature

	3 	Internal Temperature

	4 	PECI Processor Temperature 0

	5 	PECI Processor Temperature 1

	6 	PECI Processor Temperature 2

	7 	PECI Processor Temperature 3

temp4_source

	0 	(default) peci_legacy = 0, PECI Processor Temperature 0

			peci_legacy = 1, Remote 1 Temperature

	1 	Remote 1 Temperature

	2 	Remote 2 Temperature

	3 	Internal Temperature

	4 	PECI Processor Temperature 0

	5 	PECI Processor Temperature 1

	6 	PECI Processor Temperature 2

	7 	PECI Processor Temperature 3

temp[1-4]_smoothing_enable

temp[1-4]_smoothing_time

	Smooths spikes in temp readings caused by noise.

	Valid values in milliseconds are:

	35000

	17600

	11800

	 7000

	 4400

	 3000

	 1600

	  800

temp[1-4]_crit

	When the corresponding zone temperature reaches this value,

	ALL pwm outputs will got to 100%.

temp[5-8]_input

temp[5-8]_enable

	The aSC7621 can also read temperatures provided by the processor

	via the PECI bus.  Usually these are "core" temps and are relative

	to the point where the automatic thermal control circuit starts

	throttling.  This means that these are usually negative numbers.

pwm[1-3]_enable

	0		Fan off.

	1		Fan on manual control.

	2		Fan on automatic control and will run at the minimum pwm

				if the temperature for the zone is below the minimum.

	3		Fan on automatic control but will be off if the temperature

				for the zone is below the minimum.

	4-254	Ignored.

	255		Fan on full.

pwm[1-3]_auto_channels

	Bitmap as described in sysctl-interface with the following

	exceptions...

	Only the following combination of zones (and their corresponding masks)

	are valid:

	1

	2

	3

	2,3

	1,2,3

	4

	1,2,3,4

	Special values:

	0			Disabled.

	16		Fan on manual control.

	31		Fan on full.

pwm[1-3]_invert

	When set, inverts the meaning of pwm[1-3].

	i.e.  when pwm = 0, the fan will be on full and

	when pwm = 255 the fan will be off.

pwm[1-3]_freq

	PWM frequency in Hz

	Valid values in Hz are:

	10

	15

	23

	30  (default)

	38

	47

	62

	94

	23000

	24000

	25000

	26000

	27000

	28000

	29000

	30000

	Setting any other value will be ignored.

peci_enable

	Enables or disables PECI

peci_avg

	Input filter average time.

	0 	0 Sec. (no Smoothing) (default)

	1 	0.25 Sec.

	2 	0.5 Sec.

	3 	1.0 Sec.

	4 	2.0 Sec.

	5 	4.0 Sec.

	6 	8.0 Sec.

	7 	0.0 Sec.

peci_legacy

	0	Standard Mode (default)

		Remote Diode 1 reading is associated with

		Temperature Zone 1, PECI is associated with

		Zone 4

	1	Legacy Mode

		PECI is associated with Temperature Zone 1,

		Remote Diode 1 is associated with Zone 4

peci_diode

	Diode filter

	0	0.25 Sec.

	1 	1.1 Sec.

	2 	2.4 Sec.  (default)

	3 	3.4 Sec.

	4 	5.0 Sec.

	5 	6.8 Sec.

	6 	10.2 Sec.

	7 	16.4 Sec.

peci_4domain

	Four domain enable

	0 	1 or 2 Domains for enabled processors (default)

	1 	3 or 4 Domains for enabled processors

peci_domain

	Domain

	0 	Processor contains a single domain (0) 	 (default)

	1 	Processor contains two domains (0,1)

S:	Maintained

F:	arch/arm/vfp/

ASC7621 HARDWARE MONITOR DRIVER

M:	George Joseph <george.joseph@fairview5.com>

L:	lm-sensors@lm-sensors.org

S:	Maintained

F:	Documentation/hwmon/asc7621

F:	drivers/hwmon/asc7621.c

ASUS ACPI EXTRAS DRIVER

M:	Corentin Chary <corentincj@iksaif.net>

M:	Karol Kozimor <sziwan@users.sourceforge.net>

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

	  will be called adt7475.

config SENSORS_ASC7621

	tristate "Andigilog aSC7621"

	depends on HWMON && I2C

	help

	  If you say yes here you get support for the aSC7621

	  family of SMBus sensors chip found on most Intel X48, X38, 975,

	  965 and 945 desktop boards.  Currently supported chips:

	  aSC7621

	  aSC7621a

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

	  will be called asc7621.

config SENSORS_K8TEMP

	tristate "AMD Athlon64/FX or Opteron temperature sensor"

	depends on X86 && PCI && EXPERIMENTAL

obj-$(CONFIG_SENSORS_ADT7475)	+= adt7475.o

obj-$(CONFIG_SENSORS_APPLESMC)	+= applesmc.o

obj-$(CONFIG_SENSORS_AMS)	+= ams/

obj-$(CONFIG_SENSORS_ASC7621)	+= asc7621.o

obj-$(CONFIG_SENSORS_ATXP1)	+= atxp1.o

obj-$(CONFIG_SENSORS_CORETEMP)	+= coretemp.o

obj-$(CONFIG_SENSORS_DME1737)	+= dme1737.o