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Diffstat (limited to 'kernel/Documentation/hwmon/w83791d')
| -rw-r--r-- | kernel/Documentation/hwmon/w83791d | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/kernel/Documentation/hwmon/w83791d b/kernel/Documentation/hwmon/w83791d new file mode 100644 index 000000000..f4021a285 --- /dev/null +++ b/kernel/Documentation/hwmon/w83791d @@ -0,0 +1,161 @@ +Kernel driver w83791d +===================== + +Supported chips: + * Winbond W83791D + Prefix: 'w83791d' + Addresses scanned: I2C 0x2c - 0x2f + Datasheet: http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83791D_W83791Gb.pdf + +Author: Charles Spirakis <bezaur@gmail.com> + +This driver was derived from the w83781d.c and w83792d.c source files. + +Credits: + w83781d.c: + Frodo Looijaard <frodol@dds.nl>, + Philip Edelbrock <phil@netroedge.com>, + and Mark Studebaker <mdsxyz123@yahoo.com> + w83792d.c: + Shane Huang (Winbond), + Rudolf Marek <r.marek@assembler.cz> + +Additional contributors: + Sven Anders <anders@anduras.de> + Marc Hulsman <m.hulsman@tudelft.nl> + +Module Parameters +----------------- + +* init boolean + (default 0) + Use 'init=1' to have the driver do extra software initializations. + The default behavior is to do the minimum initialization possible + and depend on the BIOS to properly setup the chip. If you know you + have a w83791d and you're having problems, try init=1 before trying + reset=1. + +* reset boolean + (default 0) + Use 'reset=1' to reset the chip (via index 0x40, bit 7). The default + behavior is no chip reset to preserve BIOS settings. + +* force_subclients=bus,caddr,saddr,saddr + This is used to force the i2c addresses for subclients of + a certain chip. Example usage is `force_subclients=0,0x2f,0x4a,0x4b' + to force the subclients of chip 0x2f on bus 0 to i2c addresses + 0x4a and 0x4b. + + +Description +----------- + +This driver implements support for the Winbond W83791D chip. The W83791G +chip appears to be the same as the W83791D but is lead free. + +Detection of the chip can sometimes be foiled because it can be in an +internal state that allows no clean access (Bank with ID register is not +currently selected). If you know the address of the chip, use a 'force' +parameter; this will put it into a more well-behaved state first. + +The driver implements three temperature sensors, ten voltage sensors, +five fan rotation speed sensors and manual PWM control of each fan. + +Temperatures are measured in degrees Celsius and measurement resolution is 1 +degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when +the temperature gets higher than the Overtemperature Shutdown value; it stays +on until the temperature falls below the Hysteresis value. + +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. + +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 for all fans) to give the readings more range or accuracy. + +Each fan controlled is controlled by PWM. The PWM duty cycle can be read and +set for each fan separately. Valid values range from 0 (stop) to 255 (full). +PWM 1-3 support Thermal Cruise mode, in which the PWMs are automatically +regulated to keep respectively temp 1-3 at a certain target temperature. +See below for the description of the sysfs-interface. + +The w83791d has a global bit used to enable beeping from the speaker when an +alarm is triggered as well as a bitmask to enable or disable the beep for +specific alarms. You need both the global beep enable bit and the +corresponding beep bit to be on for a triggered alarm to sound a beep. + +The sysfs interface to the global enable is via the sysfs beep_enable file. +This file is used for both legacy and new code. + +The sysfs interface to the beep bitmask has migrated from the original legacy +method of a single sysfs beep_mask file to a newer method using multiple +*_beep files as described in .../Documentation/hwmon/sysfs-interface. + +A similar change has occurred for the bitmap corresponding to the alarms. The +original legacy method used a single sysfs alarms file containing a bitmap +of triggered alarms. The newer method uses multiple sysfs *_alarm files +(again following the pattern described in sysfs-interface). + +Since both methods read and write the underlying hardware, they can be used +interchangeably and changes in one will automatically be reflected by +the other. If you use the legacy bitmask method, your user-space code is +responsible for handling the fact that the alarms and beep_mask bitmaps +are not the same (see the table below). + +NOTE: All new code should be written to use the newer sysfs-interface +specification as that avoids bitmap problems and is the preferred interface +going forward. + +The driver reads the hardware chip values at most once every three seconds. +User mode code requesting values more often will receive cached values. + +/sys files +---------- +The sysfs-interface is documented in the 'sysfs-interface' file. Only +chip-specific options are documented here. + +pwm[1-3]_enable - this file controls mode of fan/temperature control for + fan 1-3. Fan/PWM 4-5 only support manual mode. + * 1 Manual mode + * 2 Thermal Cruise mode + * 3 Fan Speed Cruise mode (no further support) + +temp[1-3]_target - defines the target temperature for Thermal Cruise mode. + Unit: millidegree Celsius + RW + +temp[1-3]_tolerance - temperature tolerance for Thermal Cruise mode. + Specifies an interval around the target temperature + in which the fan speed is not changed. + Unit: millidegree Celsius + RW + +Alarms bitmap vs. beep_mask bitmask +------------------------------------ +For legacy code using the alarms and beep_mask files: + +in0 (VCORE) : alarms: 0x000001 beep_mask: 0x000001 +in1 (VINR0) : alarms: 0x000002 beep_mask: 0x002000 <== mismatch +in2 (+3.3VIN): alarms: 0x000004 beep_mask: 0x000004 +in3 (5VDD) : alarms: 0x000008 beep_mask: 0x000008 +in4 (+12VIN) : alarms: 0x000100 beep_mask: 0x000100 +in5 (-12VIN) : alarms: 0x000200 beep_mask: 0x000200 +in6 (-5VIN) : alarms: 0x000400 beep_mask: 0x000400 +in7 (VSB) : alarms: 0x080000 beep_mask: 0x010000 <== mismatch +in8 (VBAT) : alarms: 0x100000 beep_mask: 0x020000 <== mismatch +in9 (VINR1) : alarms: 0x004000 beep_mask: 0x004000 +temp1 : alarms: 0x000010 beep_mask: 0x000010 +temp2 : alarms: 0x000020 beep_mask: 0x000020 +temp3 : alarms: 0x002000 beep_mask: 0x000002 <== mismatch +fan1 : alarms: 0x000040 beep_mask: 0x000040 +fan2 : alarms: 0x000080 beep_mask: 0x000080 +fan3 : alarms: 0x000800 beep_mask: 0x000800 +fan4 : alarms: 0x200000 beep_mask: 0x200000 +fan5 : alarms: 0x400000 beep_mask: 0x400000 +tart1 : alarms: 0x010000 beep_mask: 0x040000 <== mismatch +tart2 : alarms: 0x020000 beep_mask: 0x080000 <== mismatch +tart3 : alarms: 0x040000 beep_mask: 0x100000 <== mismatch +case_open : alarms: 0x001000 beep_mask: 0x001000 +global_enable: alarms: -------- beep_mask: 0x800000 (modified via beep_enable) |