Documentation/hwmon/w83791d

   1 Kernel driver w83791d
   2 =====================
   3
   4 Supported chips:
   5   * Winbond W83791D
   6     Prefix: 'w83791d'
   7     Addresses scanned: I2C 0x2c - 0x2f
   8     Datasheet: http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83791D_W83791Gb.pdf
   9
  10 Author: Charles Spirakis <bezaur@gmail.com>
  11
  12 This driver was derived from the w83781d.c and w83792d.c source files.
  13
  14 Credits:
  15   w83781d.c:
  16     Frodo Looijaard <frodol@dds.nl>,
  17     Philip Edelbrock <phil@netroedge.com>,
  18     and Mark Studebaker <mdsxyz123@yahoo.com>
  19   w83792d.c:
  20     Shane Huang (Winbond),
  21     Rudolf Marek <r.marek@assembler.cz>
  22
  23 Additional contributors:
  24     Sven Anders <anders@anduras.de>
  25     Marc Hulsman <m.hulsman@tudelft.nl>
  26
  27 Module Parameters
  28 -----------------
  29
  30 * init boolean
  31   (default 0)
  32   Use 'init=1' to have the driver do extra software initializations.
  33   The default behavior is to do the minimum initialization possible
  34   and depend on the BIOS to properly setup the chip. If you know you
  35   have a w83791d and you're having problems, try init=1 before trying
  36   reset=1.
  37
  38 * reset boolean
  39   (default 0)
  40   Use 'reset=1' to reset the chip (via index 0x40, bit 7). The default
  41   behavior is no chip reset to preserve BIOS settings.
  42
  43 * force_subclients=bus,caddr,saddr,saddr
  44   This is used to force the i2c addresses for subclients of
  45   a certain chip. Example usage is `force_subclients=0,0x2f,0x4a,0x4b'
  46   to force the subclients of chip 0x2f on bus 0 to i2c addresses
  47   0x4a and 0x4b.
  48
  49
  50 Description
  51 -----------
  52
  53 This driver implements support for the Winbond W83791D chip. The W83791G
  54 chip appears to be the same as the W83791D but is lead free.
  55
  56 Detection of the chip can sometimes be foiled because it can be in an
  57 internal state that allows no clean access (Bank with ID register is not
  58 currently selected). If you know the address of the chip, use a 'force'
  59 parameter; this will put it into a more well-behaved state first.
  60
  61 The driver implements three temperature sensors, ten voltage sensors,
  62 five fan rotation speed sensors and manual PWM control of each fan.
  63
  64 Temperatures are measured in degrees Celsius and measurement resolution is 1
  65 degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when
  66 the temperature gets higher than the Overtemperature Shutdown value; it stays
  67 on until the temperature falls below the Hysteresis value.
  68
  69 Voltage sensors (also known as IN sensors) report their values in millivolts.
  70 An alarm is triggered if the voltage has crossed a programmable minimum
  71 or maximum limit.
  72
  73 Fan rotation speeds are reported in RPM (rotations per minute). An alarm is
  74 triggered if the rotation speed has dropped below a programmable limit. Fan
  75 readings can be divided by a programmable divider (1, 2, 4, 8, 16,
  76 32, 64 or 128 for all fans) to give the readings more range or accuracy.
  77
  78 Each fan controlled is controlled by PWM. The PWM duty cycle can be read and
  79 set for each fan separately. Valid values range from 0 (stop) to 255 (full).
  80 PWM 1-3 support Thermal Cruise mode, in which the PWMs are automatically
  81 regulated to keep respectively temp 1-3 at a certain target temperature.
  82 See below for the description of the sysfs-interface.
  83
  84 The w83791d has a global bit used to enable beeping from the speaker when an
  85 alarm is triggered as well as a bitmask to enable or disable the beep for
  86 specific alarms. You need both the global beep enable bit and the
  87 corresponding beep bit to be on for a triggered alarm to sound a beep.
  88
  89 The sysfs interface to the global enable is via the sysfs beep_enable file.
  90 This file is used for both legacy and new code.
  91
  92 The sysfs interface to the beep bitmask has migrated from the original legacy
  93 method of a single sysfs beep_mask file to a newer method using multiple
  94 *_beep files as described in .../Documentation/hwmon/sysfs-interface.
  95
  96 A similar change has occurred for the bitmap corresponding to the alarms. The
  97 original legacy method used a single sysfs alarms file containing a bitmap
  98 of triggered alarms. The newer method uses multiple sysfs *_alarm files
  99 (again following the pattern described in sysfs-interface).
 100
 101 Since both methods read and write the underlying hardware, they can be used
 102 interchangeably and changes in one will automatically be reflected by
 103 the other. If you use the legacy bitmask method, your user-space code is
 104 responsible for handling the fact that the alarms and beep_mask bitmaps
 105 are not the same (see the table below).
 106
 107 NOTE: All new code should be written to use the newer sysfs-interface
 108 specification as that avoids bitmap problems and is the preferred interface
 109 going forward.
 110
 111 The driver reads the hardware chip values at most once every three seconds.
 112 User mode code requesting values more often will receive cached values.
 113
 114 /sys files
 115 ----------
 116 The sysfs-interface is documented in the 'sysfs-interface' file. Only
 117 chip-specific options are documented here.
 118
 119 pwm[1-3]_enable -       this file controls mode of fan/temperature control for
 120                         fan 1-3. Fan/PWM 4-5 only support manual mode.
 121                             * 1 Manual mode
 122                             * 2 Thermal Cruise mode
 123                             * 3 Fan Speed Cruise mode (no further support)
 124
 125 temp[1-3]_target -      defines the target temperature for Thermal Cruise mode.
 126                         Unit: millidegree Celsius
 127                         RW
 128
 129 temp[1-3]_tolerance -   temperature tolerance for Thermal Cruise mode.
 130                         Specifies an interval around the target temperature
 131                         in which the fan speed is not changed.
 132                         Unit: millidegree Celsius
 133                         RW
 134
 135 Alarms bitmap vs. beep_mask bitmask
 136 ------------------------------------
 137 For legacy code using the alarms and beep_mask files:
 138
 139 in0 (VCORE)  :  alarms: 0x000001 beep_mask: 0x000001
 140 in1 (VINR0)  :  alarms: 0x000002 beep_mask: 0x002000 <== mismatch
 141 in2 (+3.3VIN):  alarms: 0x000004 beep_mask: 0x000004
 142 in3 (5VDD)   :  alarms: 0x000008 beep_mask: 0x000008
 143 in4 (+12VIN) :  alarms: 0x000100 beep_mask: 0x000100
 144 in5 (-12VIN) :  alarms: 0x000200 beep_mask: 0x000200
 145 in6 (-5VIN)  :  alarms: 0x000400 beep_mask: 0x000400
 146 in7 (VSB)    :  alarms: 0x080000 beep_mask: 0x010000 <== mismatch
 147 in8 (VBAT)   :  alarms: 0x100000 beep_mask: 0x020000 <== mismatch
 148 in9 (VINR1)  :  alarms: 0x004000 beep_mask: 0x004000
 149 temp1        :  alarms: 0x000010 beep_mask: 0x000010
 150 temp2        :  alarms: 0x000020 beep_mask: 0x000020
 151 temp3        :  alarms: 0x002000 beep_mask: 0x000002 <== mismatch
 152 fan1         :  alarms: 0x000040 beep_mask: 0x000040
 153 fan2         :  alarms: 0x000080 beep_mask: 0x000080
 154 fan3         :  alarms: 0x000800 beep_mask: 0x000800
 155 fan4         :  alarms: 0x200000 beep_mask: 0x200000
 156 fan5         :  alarms: 0x400000 beep_mask: 0x400000
 157 tart1        :  alarms: 0x010000 beep_mask: 0x040000 <== mismatch
 158 tart2        :  alarms: 0x020000 beep_mask: 0x080000 <== mismatch
 159 tart3        :  alarms: 0x040000 beep_mask: 0x100000 <== mismatch
 160 case_open    :  alarms: 0x001000 beep_mask: 0x001000
 161 global_enable:  alarms: -------- beep_mask: 0x800000 (modified via beep_enable)