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The W83627EHF and similar chips have 6 VID input pins, add support for them. The driver changes the input voltage level automatically if the current setting is not correct for the detected CPU model. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
126 lines
5.2 KiB
Plaintext
126 lines
5.2 KiB
Plaintext
Kernel driver w83627ehf
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=======================
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Supported chips:
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* Winbond W83627EHF/EHG/DHG (ISA access ONLY)
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Prefix: 'w83627ehf'
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Addresses scanned: ISA address retrieved from Super I/O registers
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Datasheet:
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http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83627EHF_%20W83627EHGb.pdf
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DHG datasheet confidential.
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Authors:
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Jean Delvare <khali@linux-fr.org>
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Yuan Mu (Winbond)
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Rudolf Marek <r.marek@assembler.cz>
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David Hubbard <david.c.hubbard@gmail.com>
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Description
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-----------
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This driver implements support for the Winbond W83627EHF, W83627EHG, and
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W83627DHG super I/O chips. We will refer to them collectively as Winbond chips.
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The chips implement three temperature sensors, five fan rotation
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speed sensors, ten analog voltage sensors (only nine for the 627DHG), one
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VID (6 pins), alarms with beep warnings (control unimplemented), and
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some automatic fan regulation strategies (plus manual fan control mode).
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Temperatures are measured in degrees Celsius and measurement resolution is 1
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degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when
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the temperature gets higher than high limit; it stays on until the temperature
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falls below the hysteresis value.
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Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
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triggered if the rotation speed has dropped below a programmable limit. Fan
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readings can be divided by a programmable divider (1, 2, 4, 8, 16, 32, 64 or
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128) to give the readings more range or accuracy. The driver sets the most
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suitable fan divisor itself. Some fans might not be present because they
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share pins with other functions.
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Voltage sensors (also known as IN sensors) report their values in millivolts.
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An alarm is triggered if the voltage has crossed a programmable minimum
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or maximum limit.
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The driver supports automatic fan control mode known as Thermal Cruise.
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In this mode, the chip attempts to keep the measured temperature in a
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predefined temperature range. If the temperature goes out of range, fan
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is driven slower/faster to reach the predefined range again.
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The mode works for fan1-fan4. Mapping of temperatures to pwm outputs is as
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follows:
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temp1 -> pwm1
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temp2 -> pwm2
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temp3 -> pwm3
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prog -> pwm4 (the programmable setting is not supported by the driver)
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/sys files
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----------
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name - this is a standard hwmon device entry. For the W83627EHF and W83627EHG,
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it is set to "w83627ehf" and for the W83627DHG it is set to "w83627dhg"
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pwm[1-4] - this file stores PWM duty cycle or DC value (fan speed) in range:
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0 (stop) to 255 (full)
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pwm[1-4]_enable - this file controls mode of fan/temperature control:
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* 1 Manual Mode, write to pwm file any value 0-255 (full speed)
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* 2 Thermal Cruise
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Thermal Cruise mode
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-------------------
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If the temperature is in the range defined by:
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pwm[1-4]_target - set target temperature, unit millidegree Celsius
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(range 0 - 127000)
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pwm[1-4]_tolerance - tolerance, unit millidegree Celsius (range 0 - 15000)
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there are no changes to fan speed. Once the temperature leaves the interval,
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fan speed increases (temp is higher) or decreases if lower than desired.
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There are defined steps and times, but not exported by the driver yet.
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pwm[1-4]_min_output - minimum fan speed (range 1 - 255), when the temperature
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is below defined range.
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pwm[1-4]_stop_time - how many milliseconds [ms] must elapse to switch
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corresponding fan off. (when the temperature was below
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defined range).
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Note: last two functions are influenced by other control bits, not yet exported
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by the driver, so a change might not have any effect.
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Implementation Details
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----------------------
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Future driver development should bear in mind that the following registers have
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different functions on the 627EHF and the 627DHG. Some registers also have
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different power-on default values, but BIOS should already be loading
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appropriate defaults. Note that bank selection must be performed as is currently
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done in the driver for all register addresses.
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0x49: only on DHG, selects temperature source for AUX fan, CPU fan0
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0x4a: not completely documented for the EHF and the DHG documentation assigns
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different behavior to bits 7 and 6, including extending the temperature
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input selection to SmartFan I, not just SmartFan III. Testing on the EHF
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will reveal whether they are compatible or not.
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0x58: Chip ID: 0xa1=EHF 0xc1=DHG
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0x5e: only on DHG, has bits to enable "current mode" temperature detection and
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critical temperature protection
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0x45b: only on EHF, bit 3, vin4 alarm (EHF supports 10 inputs, only 9 on DHG)
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0x552: only on EHF, vin4
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0x558: only on EHF, vin4 high limit
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0x559: only on EHF, vin4 low limit
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0x6b: only on DHG, SYS fan critical temperature
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0x6c: only on DHG, CPU fan0 critical temperature
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0x6d: only on DHG, AUX fan critical temperature
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0x6e: only on DHG, CPU fan1 critical temperature
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0x50-0x55 and 0x650-0x657 are marked "Test Register" for the EHF, but "Reserved
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Register" for the DHG
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The DHG also supports PECI, where the DHG queries Intel CPU temperatures, and
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the ICH8 southbridge gets that data via PECI from the DHG, so that the
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southbridge drives the fans. And the DHG supports SST, a one-wire serial bus.
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