linux/Documentation/hwmon/dme1737.rst
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   1Kernel driver dme1737
   2=====================
   3
   4Supported chips:
   5
   6  * SMSC DME1737 and compatibles (like Asus A8000)
   7
   8    Prefix: 'dme1737'
   9
  10    Addresses scanned: I2C 0x2c, 0x2d, 0x2e
  11
  12    Datasheet: Provided by SMSC upon request and under NDA
  13
  14  * SMSC SCH3112, SCH3114, SCH3116
  15
  16    Prefix: 'sch311x'
  17
  18    Addresses scanned: none, address read from Super-I/O config space
  19
  20    Datasheet: Available on the Internet
  21
  22  * SMSC SCH5027
  23
  24    Prefix: 'sch5027'
  25
  26    Addresses scanned: I2C 0x2c, 0x2d, 0x2e
  27
  28    Datasheet: Provided by SMSC upon request and under NDA
  29
  30  * SMSC SCH5127
  31
  32    Prefix: 'sch5127'
  33
  34    Addresses scanned: none, address read from Super-I/O config space
  35
  36    Datasheet: Provided by SMSC upon request and under NDA
  37
  38Authors:
  39    Juerg Haefliger <juergh@gmail.com>
  40
  41
  42Module Parameters
  43-----------------
  44
  45* force_start: bool
  46                        Enables the monitoring of voltage, fan and temp inputs
  47                        and PWM output control functions. Using this parameter
  48                        shouldn't be required since the BIOS usually takes care
  49                        of this.
  50
  51* probe_all_addr: bool
  52                        Include non-standard LPC addresses 0x162e and 0x164e
  53                        when probing for ISA devices. This is required for the
  54                        following boards:
  55                        - VIA EPIA SN18000
  56
  57
  58Description
  59-----------
  60
  61This driver implements support for the hardware monitoring capabilities of the
  62SMSC DME1737 and Asus A8000 (which are the same), SMSC SCH5027, SCH311x,
  63and SCH5127 Super-I/O chips. These chips feature monitoring of 3 temp sensors
  64temp[1-3] (2 remote diodes and 1 internal), 8 voltages in[0-7] (7 external and
  651 internal) and up to 6 fan speeds fan[1-6]. Additionally, the chips implement
  66up to 5 PWM outputs pwm[1-3,5-6] for controlling fan speeds both manually and
  67automatically.
  68
  69For the DME1737, A8000 and SCH5027, fan[1-2] and pwm[1-2] are always present.
  70Fan[3-6] and pwm[3,5-6] are optional features and their availability depends on
  71the configuration of the chip. The driver will detect which features are
  72present during initialization and create the sysfs attributes accordingly.
  73
  74For the SCH311x and SCH5127, fan[1-3] and pwm[1-3] are always present and
  75fan[4-6] and pwm[5-6] don't exist.
  76
  77The hardware monitoring features of the DME1737, A8000, and SCH5027 are only
  78accessible via SMBus, while the SCH311x and SCH5127 only provide access via
  79the ISA bus. The driver will therefore register itself as an I2C client driver
  80if it detects a DME1737, A8000, or SCH5027 and as a platform driver if it
  81detects a SCH311x or SCH5127 chip.
  82
  83
  84Voltage Monitoring
  85------------------
  86
  87The voltage inputs are sampled with 12-bit resolution and have internal
  88scaling resistors. The values returned by the driver therefore reflect true
  89millivolts and don't need scaling. The voltage inputs are mapped as follows
  90(the last column indicates the input ranges):
  91
  92DME1737, A8000::
  93
  94        in0: +5VTR      (+5V standby)           0V - 6.64V
  95        in1: Vccp       (processor core)        0V - 3V
  96        in2: VCC        (internal +3.3V)        0V - 4.38V
  97        in3: +5V                                0V - 6.64V
  98        in4: +12V                               0V - 16V
  99        in5: VTR        (+3.3V standby)         0V - 4.38V
 100        in6: Vbat       (+3.0V)                 0V - 4.38V
 101
 102SCH311x::
 103
 104        in0: +2.5V                              0V - 3.32V
 105        in1: Vccp       (processor core)        0V - 2V
 106        in2: VCC        (internal +3.3V)        0V - 4.38V
 107        in3: +5V                                0V - 6.64V
 108        in4: +12V                               0V - 16V
 109        in5: VTR        (+3.3V standby)         0V - 4.38V
 110        in6: Vbat       (+3.0V)                 0V - 4.38V
 111
 112SCH5027::
 113
 114        in0: +5VTR      (+5V standby)           0V - 6.64V
 115        in1: Vccp       (processor core)        0V - 3V
 116        in2: VCC        (internal +3.3V)        0V - 4.38V
 117        in3: V2_IN                              0V - 1.5V
 118        in4: V1_IN                              0V - 1.5V
 119        in5: VTR        (+3.3V standby)         0V - 4.38V
 120        in6: Vbat       (+3.0V)                 0V - 4.38V
 121
 122SCH5127::
 123
 124        in0: +2.5                               0V - 3.32V
 125        in1: Vccp       (processor core)        0V - 3V
 126        in2: VCC        (internal +3.3V)        0V - 4.38V
 127        in3: V2_IN                              0V - 1.5V
 128        in4: V1_IN                              0V - 1.5V
 129        in5: VTR        (+3.3V standby)         0V - 4.38V
 130        in6: Vbat       (+3.0V)                 0V - 4.38V
 131        in7: Vtrip      (+1.5V)                 0V - 1.99V
 132
 133Each voltage input has associated min and max limits which trigger an alarm
 134when crossed.
 135
 136
 137Temperature Monitoring
 138----------------------
 139
 140Temperatures are measured with 12-bit resolution and reported in millidegree
 141Celsius. The chip also features offsets for all 3 temperature inputs which -
 142when programmed - get added to the input readings. The chip does all the
 143scaling by itself and the driver therefore reports true temperatures that don't
 144need any user-space adjustments. The temperature inputs are mapped as follows
 145(the last column indicates the input ranges)::
 146
 147        temp1: Remote diode 1 (3904 type) temperature   -127C - +127C
 148        temp2: DME1737 internal temperature             -127C - +127C
 149        temp3: Remote diode 2 (3904 type) temperature   -127C - +127C
 150
 151Each temperature input has associated min and max limits which trigger an alarm
 152when crossed. Additionally, each temperature input has a fault attribute that
 153returns 1 when a faulty diode or an unconnected input is detected and 0
 154otherwise.
 155
 156
 157Fan Monitoring
 158--------------
 159
 160Fan RPMs are measured with 16-bit resolution. The chip provides inputs for 6
 161fan tachometers. All 6 inputs have an associated min limit which triggers an
 162alarm when crossed. Fan inputs 1-4 provide type attributes that need to be set
 163to the number of pulses per fan revolution that the connected tachometer
 164generates. Supported values are 1, 2, and 4. Fan inputs 5-6 only support fans
 165that generate 2 pulses per revolution. Fan inputs 5-6 also provide a max
 166attribute that needs to be set to the maximum attainable RPM (fan at 100% duty-
 167cycle) of the input. The chip adjusts the sampling rate based on this value.
 168
 169
 170PWM Output Control
 171------------------
 172
 173This chip features 5 PWM outputs. PWM outputs 1-3 are associated with fan
 174inputs 1-3 and PWM outputs 5-6 are associated with fan inputs 5-6. PWM outputs
 1751-3 can be configured to operate either in manual or automatic mode by setting
 176the appropriate enable attribute accordingly. PWM outputs 5-6 can only operate
 177in manual mode, their enable attributes are therefore read-only. When set to
 178manual mode, the fan speed is set by writing the duty-cycle value to the
 179appropriate PWM attribute. In automatic mode, the PWM attribute returns the
 180current duty-cycle as set by the fan controller in the chip. All PWM outputs
 181support the setting of the output frequency via the freq attribute.
 182
 183In automatic mode, the chip supports the setting of the PWM ramp rate which
 184defines how fast the PWM output is adjusting to changes of the associated
 185temperature input. Associating PWM outputs to temperature inputs is done via
 186temperature zones. The chip features 3 zones whose assignments to temperature
 187inputs is static and determined during initialization. These assignments can
 188be retrieved via the zone[1-3]_auto_channels_temp attributes. Each PWM output
 189is assigned to one (or hottest of multiple) temperature zone(s) through the
 190pwm[1-3]_auto_channels_zone attributes. Each PWM output has 3 distinct output
 191duty-cycles: full, low, and min. Full is internally hard-wired to 255 (100%)
 192and low and min can be programmed via pwm[1-3]_auto_point1_pwm and
 193pwm[1-3]_auto_pwm_min, respectively. The thermal thresholds of the zones are
 194programmed via zone[1-3]_auto_point[1-3]_temp and
 195zone[1-3]_auto_point1_temp_hyst:
 196
 197        =============================== =======================================
 198        pwm[1-3]_auto_point2_pwm        full-speed duty-cycle (255, i.e., 100%)
 199        pwm[1-3]_auto_point1_pwm        low-speed duty-cycle
 200        pwm[1-3]_auto_pwm_min           min-speed duty-cycle
 201
 202        zone[1-3]_auto_point3_temp      full-speed temp (all outputs)
 203        zone[1-3]_auto_point2_temp      full-speed temp
 204        zone[1-3]_auto_point1_temp      low-speed temp
 205        zone[1-3]_auto_point1_temp_hyst min-speed temp
 206        =============================== =======================================
 207
 208The chip adjusts the output duty-cycle linearly in the range of auto_point1_pwm
 209to auto_point2_pwm if the temperature of the associated zone is between
 210auto_point1_temp and auto_point2_temp. If the temperature drops below the
 211auto_point1_temp_hyst value, the output duty-cycle is set to the auto_pwm_min
 212value which only supports two values: 0 or auto_point1_pwm. That means that the
 213fan either turns completely off or keeps spinning with the low-speed
 214duty-cycle. If any of the temperatures rise above the auto_point3_temp value,
 215all PWM outputs are set to 100% duty-cycle.
 216
 217Following is another representation of how the chip sets the output duty-cycle
 218based on the temperature of the associated thermal zone:
 219
 220        =============== =============== =================
 221        Temperature     Duty-Cycle      Duty-Cycle
 222                        Rising Temp     Falling Temp
 223        =============== =============== =================
 224        full-speed      full-speed      full-speed
 225
 226        -               < linearly      -
 227                        adjusted
 228                        duty-cycle >
 229
 230        low-speed       low-speed       low-speed
 231        -               min-speed       low-speed
 232        min-speed       min-speed       min-speed
 233        -               min-speed       min-speed
 234        =============== =============== =================
 235
 236
 237Sysfs Attributes
 238----------------
 239
 240Following is a list of all sysfs attributes that the driver provides, their
 241permissions and a short description:
 242
 243=============================== ======= =======================================
 244Name                            Perm    Description
 245=============================== ======= =======================================
 246cpu0_vid                        RO      CPU core reference voltage in
 247                                        millivolts.
 248vrm                             RW      Voltage regulator module version
 249                                        number.
 250
 251in[0-7]_input                   RO      Measured voltage in millivolts.
 252in[0-7]_min                     RW      Low limit for voltage input.
 253in[0-7]_max                     RW      High limit for voltage input.
 254in[0-7]_alarm                   RO      Voltage input alarm. Returns 1 if
 255                                        voltage input is or went outside the
 256                                        associated min-max range, 0 otherwise.
 257
 258temp[1-3]_input                 RO      Measured temperature in millidegree
 259                                        Celsius.
 260temp[1-3]_min                   RW      Low limit for temp input.
 261temp[1-3]_max                   RW      High limit for temp input.
 262temp[1-3]_offset                RW      Offset for temp input. This value will
 263                                        be added by the chip to the measured
 264                                        temperature.
 265temp[1-3]_alarm                 RO      Alarm for temp input. Returns 1 if temp
 266                                        input is or went outside the associated
 267                                        min-max range, 0 otherwise.
 268temp[1-3]_fault                 RO      Temp input fault. Returns 1 if the chip
 269                                        detects a faulty thermal diode or an
 270                                        unconnected temp input, 0 otherwise.
 271
 272zone[1-3]_auto_channels_temp    RO      Temperature zone to temperature input
 273                                        mapping. This attribute is a bitfield
 274                                        and supports the following values:
 275
 276                                                - 1: temp1
 277                                                - 2: temp2
 278                                                - 4: temp3
 279zone[1-3]_auto_point1_temp_hyst RW      Auto PWM temp point1 hysteresis. The
 280                                        output of the corresponding PWM is set
 281                                        to the pwm_auto_min value if the temp
 282                                        falls below the auto_point1_temp_hyst
 283                                        value.
 284zone[1-3]_auto_point[1-3]_temp  RW      Auto PWM temp points. Auto_point1 is
 285                                        the low-speed temp, auto_point2 is the
 286                                        full-speed temp, and auto_point3 is the
 287                                        temp at which all PWM outputs are set
 288                                        to full-speed (100% duty-cycle).
 289
 290fan[1-6]_input                  RO      Measured fan speed in RPM.
 291fan[1-6]_min                    RW      Low limit for fan input.
 292fan[1-6]_alarm                  RO      Alarm for fan input. Returns 1 if fan
 293                                        input is or went below the associated
 294                                        min value, 0 otherwise.
 295fan[1-4]_type                   RW      Type of attached fan. Expressed in
 296                                        number of pulses per revolution that
 297                                        the fan generates. Supported values are
 298                                        1, 2, and 4.
 299fan[5-6]_max                    RW      Max attainable RPM at 100% duty-cycle.
 300                                        Required for chip to adjust the
 301                                        sampling rate accordingly.
 302
 303pmw[1-3,5-6]                    RO/RW   Duty-cycle of PWM output. Supported
 304                                        values are 0-255 (0%-100%). Only
 305                                        writeable if the associated PWM is in
 306                                        manual mode.
 307pwm[1-3]_enable                 RW      Enable of PWM outputs 1-3. Supported
 308                                        values are:
 309
 310                                                - 0: turned off (output @ 100%)
 311                                                - 1: manual mode
 312                                                - 2: automatic mode
 313pwm[5-6]_enable                 RO      Enable of PWM outputs 5-6. Always
 314                                        returns 1 since these 2 outputs are
 315                                        hard-wired to manual mode.
 316pmw[1-3,5-6]_freq               RW      Frequency of PWM output. Supported
 317                                        values are in the range 11Hz-30000Hz
 318                                        (default is 25000Hz).
 319pmw[1-3]_ramp_rate              RW      Ramp rate of PWM output. Determines how
 320                                        fast the PWM duty-cycle will change
 321                                        when the PWM is in automatic mode.
 322                                        Expressed in ms per PWM step. Supported
 323                                        values are in the range 0ms-206ms
 324                                        (default is 0, which means the duty-
 325                                        cycle changes instantly).
 326pwm[1-3]_auto_channels_zone     RW      PWM output to temperature zone mapping.
 327                                        This attribute is a bitfield and
 328                                        supports the following values:
 329
 330                                                - 1: zone1
 331                                                - 2: zone2
 332                                                - 4: zone3
 333                                                - 6: highest of zone[2-3]
 334                                                - 7: highest of zone[1-3]
 335pwm[1-3]_auto_pwm_min           RW      Auto PWM min pwm. Minimum PWM duty-
 336                                        cycle. Supported values are 0 or
 337                                        auto_point1_pwm.
 338pwm[1-3]_auto_point1_pwm        RW      Auto PWM pwm point. Auto_point1 is the
 339                                        low-speed duty-cycle.
 340pwm[1-3]_auto_point2_pwm        RO      Auto PWM pwm point. Auto_point2 is the
 341                                        full-speed duty-cycle which is hard-
 342                                        wired to 255 (100% duty-cycle).
 343=============================== ======= =======================================
 344
 345Chip Differences
 346----------------
 347
 348======================= ======= ======= ======= =======
 349Feature                 dme1737 sch311x sch5027 sch5127
 350======================= ======= ======= ======= =======
 351temp[1-3]_offset        yes     yes
 352vid                     yes
 353zone3                   yes     yes     yes
 354zone[1-3]_hyst          yes     yes
 355pwm min/off             yes     yes
 356fan3                    opt     yes     opt     yes
 357pwm3                    opt     yes     opt     yes
 358fan4                    opt             opt
 359fan5                    opt             opt
 360pwm5                    opt             opt
 361fan6                    opt             opt
 362pwm6                    opt             opt
 363in7                                             yes
 364======================= ======= ======= ======= =======
 365