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+Kernel driver w83791d
+ * 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 <firstname.lastname@example.org>
+This driver was derived from the w83781d.c and w83792d.c source files.
+ Frodo Looijaard <email@example.com>,
+ Philip Edelbrock <firstname.lastname@example.org>,
+ and Mark Studebaker <email@example.com>
+ Chunhao Huang <DZShen@Winbond.com.tw>,
+ Rudolf Marek <firstname.lastname@example.org>
+ Sven Anders <email@example.com>
+ Marc Hulsman <firstname.lastname@example.org>
+* 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 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.
+ 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.
+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
+The driver reads the hardware chip values at most once every three seconds.
+User mode code requesting values more often will receive cached values.
+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
+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
+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)