mirror of
https://github.com/torvalds/linux.git
synced 2024-11-08 21:21:47 +00:00
c43524b580
Add description of pwm[1-4]_start_output, pwm[1-4]_step_output, pwm[1-4]_stop_output, and pwm[1-4]_max_output attributes to driver documentation. Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com> Acked-by: Jean Delvare <khali@linux-fr.org>
191 lines
8.0 KiB
Plaintext
191 lines
8.0 KiB
Plaintext
Kernel driver w83627ehf
|
|
=======================
|
|
|
|
Supported chips:
|
|
* Winbond W83627EHF/EHG (ISA access ONLY)
|
|
Prefix: 'w83627ehf'
|
|
Addresses scanned: ISA address retrieved from Super I/O registers
|
|
Datasheet: not available
|
|
* Winbond W83627DHG
|
|
Prefix: 'w83627dhg'
|
|
Addresses scanned: ISA address retrieved from Super I/O registers
|
|
Datasheet: not available
|
|
* Winbond W83627DHG-P
|
|
Prefix: 'w83627dhg'
|
|
Addresses scanned: ISA address retrieved from Super I/O registers
|
|
Datasheet: not available
|
|
* Winbond W83627UHG
|
|
Prefix: 'w83627uhg'
|
|
Addresses scanned: ISA address retrieved from Super I/O registers
|
|
Datasheet: available from www.nuvoton.com
|
|
* Winbond W83667HG
|
|
Prefix: 'w83667hg'
|
|
Addresses scanned: ISA address retrieved from Super I/O registers
|
|
Datasheet: not available
|
|
* Winbond W83667HG-B
|
|
Prefix: 'w83667hg'
|
|
Addresses scanned: ISA address retrieved from Super I/O registers
|
|
Datasheet: Available from Nuvoton upon request
|
|
* Nuvoton NCT6775F/W83667HG-I
|
|
Prefix: 'nct6775'
|
|
Addresses scanned: ISA address retrieved from Super I/O registers
|
|
Datasheet: Available from Nuvoton upon request
|
|
* Nuvoton NCT6776F
|
|
Prefix: 'nct6776'
|
|
Addresses scanned: ISA address retrieved from Super I/O registers
|
|
Datasheet: Available from Nuvoton upon request
|
|
|
|
Authors:
|
|
Jean Delvare <khali@linux-fr.org>
|
|
Yuan Mu (Winbond)
|
|
Rudolf Marek <r.marek@assembler.cz>
|
|
David Hubbard <david.c.hubbard@gmail.com>
|
|
Gong Jun <JGong@nuvoton.com>
|
|
|
|
Description
|
|
-----------
|
|
|
|
This driver implements support for the Winbond W83627EHF, W83627EHG,
|
|
W83627DHG, W83627DHG-P, W83627UHG, W83667HG, W83667HG-B, W83667HG-I
|
|
(NCT6775F), and NCT6776F super I/O chips. We will refer to them collectively
|
|
as Winbond chips.
|
|
|
|
The chips implement 3 to 4 temperature sensors (9 for NCT6775F and NCT6776F),
|
|
2 to 5 fan rotation speed sensors, 8 to 10 analog voltage sensors, one VID
|
|
(except for 627UHG), alarms with beep warnings (control unimplemented),
|
|
and some automatic fan regulation strategies (plus manual fan control mode).
|
|
|
|
The temperature sensor sources on W82677HG-B, NCT6775F, and NCT6776F are
|
|
configurable. temp4 and higher attributes are only reported if its temperature
|
|
source differs from the temperature sources of the already reported temperature
|
|
sensors. The configured source for each of the temperature sensors is provided
|
|
in tempX_label.
|
|
|
|
Temperatures are measured in degrees Celsius and measurement resolution is 1
|
|
degC for temp1 and and 0.5 degC for temp2 and temp3. For temp4 and higher,
|
|
resolution is 1 degC for W83667HG-B and 0.0 degC for NCT6775F and NCT6776F.
|
|
An alarm is triggered when the temperature gets higher than high limit;
|
|
it stays on until the temperature falls below the hysteresis value.
|
|
Alarms are only supported for temp1, temp2, and temp3.
|
|
|
|
Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
|
|
triggered if the rotation speed has dropped below a programmable limit. Fan
|
|
readings can be divided by a programmable divider (1, 2, 4, 8, 16, 32, 64 or
|
|
128) to give the readings more range or accuracy. The driver sets the most
|
|
suitable fan divisor itself. Some fans might not be present because they
|
|
share pins with other functions.
|
|
|
|
Voltage sensors (also known as IN sensors) report their values in millivolts.
|
|
An alarm is triggered if the voltage has crossed a programmable minimum
|
|
or maximum limit.
|
|
|
|
The driver supports automatic fan control mode known as Thermal Cruise.
|
|
In this mode, the chip attempts to keep the measured temperature in a
|
|
predefined temperature range. If the temperature goes out of range, fan
|
|
is driven slower/faster to reach the predefined range again.
|
|
|
|
The mode works for fan1-fan4. Mapping of temperatures to pwm outputs is as
|
|
follows:
|
|
|
|
temp1 -> pwm1
|
|
temp2 -> pwm2
|
|
temp3 -> pwm3 (not on 627UHG)
|
|
prog -> pwm4 (not on 667HG and 667HG-B; the programmable setting is not
|
|
supported by the driver)
|
|
|
|
/sys files
|
|
----------
|
|
|
|
name - this is a standard hwmon device entry, it contains the name of
|
|
the device (see the prefix in the list of supported devices at
|
|
the top of this file)
|
|
|
|
pwm[1-4] - this file stores PWM duty cycle or DC value (fan speed) in range:
|
|
0 (stop) to 255 (full)
|
|
|
|
pwm[1-4]_enable - this file controls mode of fan/temperature control:
|
|
* 1 Manual mode, write to pwm file any value 0-255 (full speed)
|
|
* 2 "Thermal Cruise" mode
|
|
* 3 "Fan Speed Cruise" mode
|
|
* 4 "Smart Fan III" mode
|
|
* 5 "Smart Fan IV" mode
|
|
|
|
SmartFan III mode is not supported on NCT6776F.
|
|
|
|
SmartFan IV mode is configurable only if it was configured at system
|
|
startup, and is only supported for W83677HG-B, NCT6775F, and NCT6776F.
|
|
SmartFan IV operational parameters can not be configured at this time,
|
|
and the various pwm attributes are not used in SmartFan IV mode.
|
|
The attributes can be written to, which is useful if you plan to
|
|
configure the system for a different pwm mode. However, the information
|
|
returned when reading pwm attributes is unrelated to SmartFan IV
|
|
operation.
|
|
|
|
pwm[1-4]_mode - controls if output is PWM or DC level
|
|
* 0 DC output (0 - 12v)
|
|
* 1 PWM output
|
|
|
|
Thermal Cruise mode
|
|
-------------------
|
|
|
|
If the temperature is in the range defined by:
|
|
|
|
pwm[1-4]_target - set target temperature, unit millidegree Celsius
|
|
(range 0 - 127000)
|
|
pwm[1-4]_tolerance - tolerance, unit millidegree Celsius (range 0 - 15000)
|
|
|
|
there are no changes to fan speed. Once the temperature leaves the interval,
|
|
fan speed increases (temp is higher) or decreases if lower than desired.
|
|
There are defined steps and times, but not exported by the driver yet.
|
|
|
|
pwm[1-4]_min_output - minimum fan speed (range 1 - 255), when the temperature
|
|
is below defined range.
|
|
pwm[1-4]_stop_time - how many milliseconds [ms] must elapse to switch
|
|
corresponding fan off. (when the temperature was below
|
|
defined range).
|
|
pwm[1-4]_start_output-minimum fan speed (range 1 - 255) when spinning up
|
|
pwm[1-4]_step_output- rate of fan speed change (1 - 255)
|
|
pwm[1-4]_stop_output- minimum fan speed (range 1 - 255) when spinning down
|
|
pwm[1-4]_max_output - maximum fan speed (range 1 - 255), when the temperature
|
|
is above defined range.
|
|
|
|
Note: last six functions are influenced by other control bits, not yet exported
|
|
by the driver, so a change might not have any effect.
|
|
|
|
Implementation Details
|
|
----------------------
|
|
|
|
Future driver development should bear in mind that the following registers have
|
|
different functions on the 627EHF and the 627DHG. Some registers also have
|
|
different power-on default values, but BIOS should already be loading
|
|
appropriate defaults. Note that bank selection must be performed as is currently
|
|
done in the driver for all register addresses.
|
|
|
|
0x49: only on DHG, selects temperature source for AUX fan, CPU fan0
|
|
0x4a: not completely documented for the EHF and the DHG documentation assigns
|
|
different behavior to bits 7 and 6, including extending the temperature
|
|
input selection to SmartFan I, not just SmartFan III. Testing on the EHF
|
|
will reveal whether they are compatible or not.
|
|
|
|
0x58: Chip ID: 0xa1=EHF 0xc1=DHG
|
|
0x5e: only on DHG, has bits to enable "current mode" temperature detection and
|
|
critical temperature protection
|
|
0x45b: only on EHF, bit 3, vin4 alarm (EHF supports 10 inputs, only 9 on DHG)
|
|
0x552: only on EHF, vin4
|
|
0x558: only on EHF, vin4 high limit
|
|
0x559: only on EHF, vin4 low limit
|
|
0x6b: only on DHG, SYS fan critical temperature
|
|
0x6c: only on DHG, CPU fan0 critical temperature
|
|
0x6d: only on DHG, AUX fan critical temperature
|
|
0x6e: only on DHG, CPU fan1 critical temperature
|
|
|
|
0x50-0x55 and 0x650-0x657 are marked "Test Register" for the EHF, but "Reserved
|
|
Register" for the DHG
|
|
|
|
The DHG also supports PECI, where the DHG queries Intel CPU temperatures, and
|
|
the ICH8 southbridge gets that data via PECI from the DHG, so that the
|
|
southbridge drives the fans. And the DHG supports SST, a one-wire serial bus.
|
|
|
|
The DHG-P has an additional automatic fan speed control mode named Smart Fan
|
|
(TM) III+. This mode is not yet supported by the driver.
|