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diff --git a/Documentation/hwmon/asc7621.rst b/Documentation/hwmon/asc7621.rst new file mode 100644 index 000000000000..b5a9fad0f172 --- /dev/null +++ b/Documentation/hwmon/asc7621.rst @@ -0,0 +1,326 @@ +===================== +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) + = ================================================== |