Documentation/hwmon/amc6821

   1 Kernel driver amc6821
   2 =====================
   3
   4 Supported chips:
   5         Prefix: 'amc6821'
   6         Addresses scanned: 0x18, 0x19, 0x1a, 0x2c, 0x2d, 0x2e, 0x4c, 0x4d, 0x4e
   7         Datasheet: http://focus.ti.com/docs/prod/folders/print/amc6821.html
   8
   9 Authors:
  10         Tomaz Mertelj <tomaz.mertelj@guest.arnes.si>
  11
  12
  13 Description
  14 -----------
  15
  16 This driver implements support for the Texas Instruments amc6821 chip.
  17 The chip has one on-chip and one remote temperature sensor and one pwm fan
  18 regulator.
  19 The pwm can be controlled either from software or automatically.
  20
  21 The driver provides the following sensor accesses in sysfs:
  22
  23 temp1_input             ro      on-chip temperature
  24 temp1_min               rw      "
  25 temp1_max               rw      "
  26 temp1_crit              rw      "
  27 temp1_min_alarm         ro      "
  28 temp1_max_alarm         ro      "
  29 temp1_crit_alarm        ro      "
  30
  31 temp2_input             ro      remote temperature
  32 temp2_min               rw      "
  33 temp2_max               rw      "
  34 temp2_crit              rw      "
  35 temp2_min_alarm         ro      "
  36 temp2_max_alarm         ro      "
  37 temp2_crit_alarm        ro      "
  38 temp2_fault             ro      "
  39
  40 fan1_input              ro      tachometer speed
  41 fan1_min                rw      "
  42 fan1_max                rw      "
  43 fan1_fault              ro      "
  44 fan1_div                rw      Fan divisor can be either 2 or 4.
  45
  46 pwm1                    rw      pwm1
  47 pwm1_enable             rw      regulator mode, 1=open loop, 2=fan controlled
  48                                 by remote temperature, 3=fan controlled by
  49                                 combination of the on-chip temperature and
  50                                 remote-sensor temperature,
  51 pwm1_auto_channels_temp ro      1 if pwm_enable==2, 3 if pwm_enable==3
  52 pwm1_auto_point1_pwm    ro      Hardwired to 0, shared for both
  53                                 temperature channels.
  54 pwm1_auto_point2_pwm    rw      This value is shared for both temperature
  55                                 channels.
  56 pwm1_auto_point3_pwm    rw      Hardwired to 255, shared for both
  57                                 temperature channels.
  58
  59 temp1_auto_point1_temp  ro      Hardwired to temp2_auto_point1_temp
  60                                 which is rw. Below this temperature fan stops.
  61 temp1_auto_point2_temp  rw      The low-temperature limit of the proportional
  62                                 range. Below this temperature
  63                                 pwm1 = pwm1_auto_point2_pwm. It can go from
  64                                 0 degree C to 124 degree C in steps of
  65                                 4 degree C. Read it out after writing to get
  66                                 the actual value.
  67 temp1_auto_point3_temp  rw      Above this temperature fan runs at maximum
  68                                 speed. It can go from temp1_auto_point2_temp.
  69                                 It can only have certain discrete values
  70                                 which depend on temp1_auto_point2_temp and
  71                                 pwm1_auto_point2_pwm. Read it out after
  72                                 writing to get the actual value.
  73
  74 temp2_auto_point1_temp  rw      Must be between 0 degree C and 63 degree C and
  75                                 it defines the passive cooling temperature.
  76                                 Below this temperature the fan stops in
  77                                 the closed loop mode.
  78 temp2_auto_point2_temp  rw      The low-temperature limit of the proportional
  79                                 range. Below this temperature
  80                                 pwm1 = pwm1_auto_point2_pwm. It can go from
  81                                 0 degree C to 124 degree C in steps
  82                                 of 4 degree C.
  83
  84 temp2_auto_point3_temp  rw      Above this temperature fan runs at maximum
  85                                 speed. It can only have certain discrete
  86                                 values which depend on temp2_auto_point2_temp
  87                                 and pwm1_auto_point2_pwm. Read it out after
  88                                 writing to get actual value.
  89
  90
  91 Module parameters
  92 -----------------
  93
  94 If your board has a BIOS that initializes the amc6821 correctly, you should
  95 load the module with: init=0.
  96
  97 If your board BIOS doesn't initialize the chip, or you want
  98 different settings, you can set the following parameters:
  99 init=1,
 100 pwminv: 0 default pwm output, 1 inverts pwm output.
 101