hwmon: Driver for Andigilog aSC7621 family monitoring chips

Hwmon driver for Andigilog aSC7621 family monitoring chips.

Signed-off-by: George Joseph <george.joseph@fairview5.com>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 296 insertions, 0 deletions

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+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)