diff options
Diffstat (limited to 'Documentation/hwmon/w83791d.rst')
| -rw-r--r-- | Documentation/hwmon/w83791d.rst | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/Documentation/hwmon/w83791d.rst b/Documentation/hwmon/w83791d.rst new file mode 100644 index 000000000..3adaed39b --- /dev/null +++ b/Documentation/hwmon/w83791d.rst @@ -0,0 +1,180 @@ +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>, + - 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.rst`. + +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: + +============= ======== ========= ========================== +Signal Alarms beep_mask Obs +============= ======== ========= ========================== +in0 (VCORE) 0x000001 0x000001 +in1 (VINR0) 0x000002 0x002000 <== mismatch +in2 (+3.3VIN) 0x000004 0x000004 +in3 (5VDD) 0x000008 0x000008 +in4 (+12VIN) 0x000100 0x000100 +in5 (-12VIN) 0x000200 0x000200 +in6 (-5VIN) 0x000400 0x000400 +in7 (VSB) 0x080000 0x010000 <== mismatch +in8 (VBAT) 0x100000 0x020000 <== mismatch +in9 (VINR1) 0x004000 0x004000 +temp1 0x000010 0x000010 +temp2 0x000020 0x000020 +temp3 0x002000 0x000002 <== mismatch +fan1 0x000040 0x000040 +fan2 0x000080 0x000080 +fan3 0x000800 0x000800 +fan4 0x200000 0x200000 +fan5 0x400000 0x400000 +tart1 0x010000 0x040000 <== mismatch +tart2 0x020000 0x080000 <== mismatch +tart3 0x040000 0x100000 <== mismatch +case_open 0x001000 0x001000 +global_enable - 0x800000 (modified via beep_enable) +============= ======== ========= ========================== |