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diff --git a/Documentation/i2c/chips/lm85 b/Documentation/i2c/chips/lm85 deleted file mode 100644 index 9549237530cf..000000000000 --- a/Documentation/i2c/chips/lm85 +++ /dev/null @@ -1,221 +0,0 @@ -Kernel driver lm85 -================== - -Supported chips: - * National Semiconductor LM85 (B and C versions) - Prefix: 'lm85' - Addresses scanned: I2C 0x2c, 0x2d, 0x2e - Datasheet: http://www.national.com/pf/LM/LM85.html - * Analog Devices ADM1027 - Prefix: 'adm1027' - Addresses scanned: I2C 0x2c, 0x2d, 0x2e - Datasheet: http://www.analog.com/en/prod/0,,766_825_ADM1027,00.html - * Analog Devices ADT7463 - Prefix: 'adt7463' - Addresses scanned: I2C 0x2c, 0x2d, 0x2e - Datasheet: http://www.analog.com/en/prod/0,,766_825_ADT7463,00.html - * SMSC EMC6D100, SMSC EMC6D101 - Prefix: 'emc6d100' - Addresses scanned: I2C 0x2c, 0x2d, 0x2e - Datasheet: http://www.smsc.com/main/tools/discontinued/6d100.pdf - * SMSC EMC6D102 - Prefix: 'emc6d102' - Addresses scanned: I2C 0x2c, 0x2d, 0x2e - Datasheet: http://www.smsc.com/main/catalog/emc6d102.html - -Authors: - Philip Pokorny <ppokorny@penguincomputing.com>, - Frodo Looijaard <frodol@dds.nl>, - Richard Barrington <rich_b_nz@clear.net.nz>, - Margit Schubert-While <margitsw@t-online.de>, - Justin Thiessen <jthiessen@penguincomputing.com> - -Description ------------ - -This driver implements support for the National Semiconductor LM85 and -compatible chips including the Analog Devices ADM1027, ADT7463 and -SMSC EMC6D10x chips family. - -The LM85 uses the 2-wire interface compatible with the SMBUS 2.0 -specification. Using an analog to digital converter it measures three (3) -temperatures and five (5) voltages. It has four (4) 16-bit counters for -measuring fan speed. Five (5) digital inputs are provided for sampling the -VID signals from the processor to the VRM. Lastly, there are three (3) PWM -outputs that can be used to control fan speed. - -The voltage inputs have internal scaling resistors so that the following -voltage can be measured without external resistors: - - 2.5V, 3.3V, 5V, 12V, and CPU core voltage (2.25V) - -The temperatures measured are one internal diode, and two remote diodes. -Remote 1 is generally the CPU temperature. These inputs are designed to -measure a thermal diode like the one in a Pentium 4 processor in a socket -423 or socket 478 package. They can also measure temperature using a -transistor like the 2N3904. - -A sophisticated control system for the PWM outputs is designed into the -LM85 that allows fan speed to be adjusted automatically based on any of the -three temperature sensors. Each PWM output is individually adjustable and -programmable. Once configured, the LM85 will adjust the PWM outputs in -response to the measured temperatures without further host intervention. -This feature can also be disabled for manual control of the PWM's. - -Each of the measured inputs (voltage, temperature, fan speed) has -corresponding high/low limit values. The LM85 will signal an ALARM if any -measured value exceeds either limit. - -The LM85 samples all inputs continuously. The lm85 driver will not read -the registers more often than once a second. Further, configuration data is -only read once each 5 minutes. There is twice as much config data as -measurements, so this would seem to be a worthwhile optimization. - -Special Features ----------------- - -The LM85 has four fan speed monitoring modes. The ADM1027 has only two. -Both have special circuitry to compensate for PWM interactions with the -TACH signal from the fans. The ADM1027 can be configured to measure the -speed of a two wire fan, but the input conditioning circuitry is different -for 3-wire and 2-wire mode. For this reason, the 2-wire fan modes are not -exposed to user control. The BIOS should initialize them to the correct -mode. If you've designed your own ADM1027, you'll have to modify the -init_client function and add an insmod parameter to set this up. - -To smooth the response of fans to changes in temperature, the LM85 has an -optional filter for smoothing temperatures. The ADM1027 has the same -config option but uses it to rate limit the changes to fan speed instead. - -The ADM1027 and ADT7463 have a 10-bit ADC and can therefore measure -temperatures with 0.25 degC resolution. They also provide an offset to the -temperature readings that is automatically applied during measurement. -This offset can be used to zero out any errors due to traces and placement. -The documentation says that the offset is in 0.25 degC steps, but in -initial testing of the ADM1027 it was 1.00 degC steps. Analog Devices has -confirmed this "bug". The ADT7463 is reported to work as described in the -documentation. The current lm85 driver does not show the offset register. - -The ADT7463 has a THERM asserted counter. This counter has a 22.76ms -resolution and a range of 5.8 seconds. The driver implements a 32-bit -accumulator of the counter value to extend the range to over a year. The -counter will stay at it's max value until read. - -See the vendor datasheets for more information. There is application note -from National (AN-1260) with some additional information about the LM85. -The Analog Devices datasheet is very detailed and describes a procedure for -determining an optimal configuration for the automatic PWM control. - -The SMSC EMC6D100 & EMC6D101 monitor external voltages, temperatures, and -fan speeds. They use this monitoring capability to alert the system to out -of limit conditions and can automatically control the speeds of multiple -fans in a PC or embedded system. The EMC6D101, available in a 24-pin SSOP -package, and the EMC6D100, available in a 28-pin SSOP package, are designed -to be register compatible. The EMC6D100 offers all the features of the -EMC6D101 plus additional voltage monitoring and system control features. -Unfortunately it is not possible to distinguish between the package -versions on register level so these additional voltage inputs may read -zero. The EMC6D102 features addtional ADC bits thus extending precision -of voltage and temperature channels. - - -Hardware Configurations ------------------------ - -The LM85 can be jumpered for 3 different SMBus addresses. There are -no other hardware configuration options for the LM85. - -The lm85 driver detects both LM85B and LM85C revisions of the chip. See the -datasheet for a complete description of the differences. Other than -identifying the chip, the driver behaves no differently with regard to -these two chips. The LM85B is recommended for new designs. - -The ADM1027 and ADT7463 chips have an optional SMBALERT output that can be -used to signal the chipset in case a limit is exceeded or the temperature -sensors fail. Individual sensor interrupts can be masked so they won't -trigger SMBALERT. The SMBALERT output if configured replaces one of the other -functions (PWM2 or IN0). This functionality is not implemented in current -driver. - -The ADT7463 also has an optional THERM output/input which can be connected -to the processor PROC_HOT output. If available, the autofan control -dynamic Tmin feature can be enabled to keep the system temperature within -spec (just?!) with the least possible fan noise. - -Configuration Notes -------------------- - -Besides standard interfaces driver adds following: - -* Temperatures and Zones - -Each temperature sensor is associated with a Zone. There are three -sensors and therefore three zones (# 1, 2 and 3). Each zone has the following -temperature configuration points: - -* temp#_auto_temp_off - temperature below which fans should be off or spinning very low. -* temp#_auto_temp_min - temperature over which fans start to spin. -* temp#_auto_temp_max - temperature when fans spin at full speed. -* temp#_auto_temp_crit - temperature when all fans will run full speed. - -* PWM Control - -There are three PWM outputs. The LM85 datasheet suggests that the -pwm3 output control both fan3 and fan4. Each PWM can be individually -configured and assigned to a zone for it's control value. Each PWM can be -configured individually according to the following options. - -* pwm#_auto_pwm_min - this specifies the PWM value for temp#_auto_temp_off - temperature. (PWM value from 0 to 255) - -* pwm#_auto_pwm_freq - select base frequency of PWM output. You can select - in range of 10.0 to 94.0 Hz in .1 Hz units. - (Values 100 to 940). - -The pwm#_auto_pwm_freq can be set to one of the following 8 values. Setting the -frequency to a value not on this list, will result in the next higher frequency -being selected. The actual device frequency may vary slightly from this -specification as designed by the manufacturer. Consult the datasheet for more -details. (PWM Frequency values: 100, 150, 230, 300, 380, 470, 620, 940) - -* pwm#_auto_pwm_minctl - this flags selects for temp#_auto_temp_off temperature - the bahaviour of fans. Write 1 to let fans spinning at - pwm#_auto_pwm_min or write 0 to let them off. - -NOTE: It has been reported that there is a bug in the LM85 that causes the flag -to be associated with the zones not the PWMs. This contradicts all the -published documentation. Setting pwm#_min_ctl in this case actually affects all -PWMs controlled by zone '#'. - -* PWM Controlling Zone selection - -* pwm#_auto_channels - controls zone that is associated with PWM - -Configuration choices: - - Value Meaning - ------ ------------------------------------------------ - 1 Controlled by Zone 1 - 2 Controlled by Zone 2 - 3 Controlled by Zone 3 - 23 Controlled by higher temp of Zone 2 or 3 - 123 Controlled by highest temp of Zone 1, 2 or 3 - 0 PWM always 0% (off) - -1 PWM always 100% (full on) - -2 Manual control (write to 'pwm#' to set) - -The National LM85's have two vendor specific configuration -features. Tach. mode and Spinup Control. For more details on these, -see the LM85 datasheet or Application Note AN-1260. - -The Analog Devices ADM1027 has several vendor specific enhancements. -The number of pulses-per-rev of the fans can be set, Tach monitoring -can be optimized for PWM operation, and an offset can be applied to -the temperatures to compensate for systemic errors in the -measurements. - -In addition to the ADM1027 features, the ADT7463 also has Tmin control -and THERM asserted counts. Automatic Tmin control acts to adjust the -Tmin value to maintain the measured temperature sensor at a specified -temperature. There isn't much documentation on this feature in the -ADT7463 data sheet. This is not supported by current driver. |