b180d05084
Add support for the ADT7473 to the adt7475 driver, and mark the adt7473 driver for removal. The ADT7473 and ADT7475 chips are almost the same chip and essentially compatible, so there's no point in having separate drivers for them. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: "Mark M. Hoffman" <mhoffman@lightlink.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Jordan Crouse <jordan@cosmicpenguin.net> Cc: "Darrick J. Wong" <djwong@us.ibm.com>
74 lines
2.8 KiB
Text
74 lines
2.8 KiB
Text
Kernel driver adt7473
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======================
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Supported chips:
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* Analog Devices ADT7473
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Prefix: 'adt7473'
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Addresses scanned: I2C 0x2C, 0x2D, 0x2E
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Datasheet: Publicly available at the Analog Devices website
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Author: Darrick J. Wong
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This driver is depreacted, please use the adt7475 driver instead.
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Description
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-----------
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This driver implements support for the Analog Devices ADT7473 chip family.
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The ADT7473 uses the 2-wire interface compatible with the SMBUS 2.0
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specification. Using an analog to digital converter it measures three (3)
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temperatures and two (2) voltages. It has four (4) 16-bit counters for
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measuring fan speed. There are three (3) PWM outputs that can be used
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to control fan speed.
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A sophisticated control system for the PWM outputs is designed into the
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ADT7473 that allows fan speed to be adjusted automatically based on any of the
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three temperature sensors. Each PWM output is individually adjustable and
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programmable. Once configured, the ADT7473 will adjust the PWM outputs in
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response to the measured temperatures without further host intervention.
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This feature can also be disabled for manual control of the PWM's.
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Each of the measured inputs (voltage, temperature, fan speed) has
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corresponding high/low limit values. The ADT7473 will signal an ALARM if
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any measured value exceeds either limit.
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The ADT7473 samples all inputs continuously. The driver will not read
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the registers more often than once every other second. Further,
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configuration data is only read once per minute.
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Special Features
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----------------
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The ADT7473 have a 10-bit ADC and can therefore measure temperatures
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with 0.25 degC resolution. Temperature readings can be configured either
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for twos complement format or "Offset 64" format, wherein 63 is subtracted
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from the raw value to get the temperature value.
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The Analog Devices datasheet is very detailed and describes a procedure for
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determining an optimal configuration for the automatic PWM control.
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Configuration Notes
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-------------------
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Besides standard interfaces driver adds the following:
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* PWM Control
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* pwm#_auto_point1_pwm and temp#_auto_point1_temp and
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* pwm#_auto_point2_pwm and temp#_auto_point2_temp -
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point1: Set the pwm speed at a lower temperature bound.
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point2: Set the pwm speed at a higher temperature bound.
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The ADT7473 will scale the pwm between the lower and higher pwm speed when
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the temperature is between the two temperature boundaries. PWM values range
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from 0 (off) to 255 (full speed). Fan speed will be set to maximum when the
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temperature sensor associated with the PWM control exceeds temp#_max.
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Notes
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-----
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The NVIDIA binary driver presents an ADT7473 chip via an on-card i2c bus.
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Unfortunately, they fail to set the i2c adapter class, so this driver may
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fail to find the chip until the nvidia driver is patched.
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