Documentation/hwmon/pmbus.rst

   1 Kernel driver pmbus
   2 ===================
   3
   4 Supported chips:
   5
   6   * Ericsson BMR453, BMR454
   7
   8     Prefixes: 'bmr453', 'bmr454'
   9
  10     Addresses scanned: -
  11
  12     Datasheet:
  13
  14  http://archive.ericsson.net/service/internet/picov/get?DocNo=28701-EN/LZT146395
  15
  16   * ON Semiconductor ADP4000, NCP4200, NCP4208
  17
  18     Prefixes: 'adp4000', 'ncp4200', 'ncp4208'
  19
  20     Addresses scanned: -
  21
  22     Datasheets:
  23
  24         https://www.onsemi.com/pub_link/Collateral/ADP4000-D.PDF
  25
  26         https://www.onsemi.com/pub_link/Collateral/NCP4200-D.PDF
  27
  28         https://www.onsemi.com/pub_link/Collateral/JUNE%202009-%20REV.%200.PDF
  29
  30   * Lineage Power
  31
  32     Prefixes: 'mdt040', 'pdt003', 'pdt006', 'pdt012', 'udt020'
  33
  34     Addresses scanned: -
  35
  36     Datasheets:
  37
  38         http://www.lineagepower.com/oem/pdf/PDT003A0X.pdf
  39
  40         http://www.lineagepower.com/oem/pdf/PDT006A0X.pdf
  41
  42         http://www.lineagepower.com/oem/pdf/PDT012A0X.pdf
  43
  44         http://www.lineagepower.com/oem/pdf/UDT020A0X.pdf
  45
  46         http://www.lineagepower.com/oem/pdf/MDT040A0X.pdf
  47
  48   * Texas Instruments TPS40400, TPS544B20, TPS544B25, TPS544C20, TPS544C25
  49
  50     Prefixes: 'tps40400', 'tps544b20', 'tps544b25', 'tps544c20', 'tps544c25'
  51
  52     Addresses scanned: -
  53
  54     Datasheets:
  55
  56         https://www.ti.com/lit/gpn/tps40400
  57
  58         https://www.ti.com/lit/gpn/tps544b20
  59
  60         https://www.ti.com/lit/gpn/tps544b25
  61
  62         https://www.ti.com/lit/gpn/tps544c20
  63
  64         https://www.ti.com/lit/gpn/tps544c25
  65
  66   * Maxim MAX20796
  67
  68     Prefix: 'max20796'
  69
  70     Addresses scanned: -
  71
  72     Datasheet:
  73
  74         Not published
  75
  76   * Generic PMBus devices
  77
  78     Prefix: 'pmbus'
  79
  80     Addresses scanned: -
  81
  82     Datasheet: n.a.
  83
  84
  85 Author: Guenter Roeck <linux@roeck-us.net>
  86
  87
  88 Description
  89 -----------
  90
  91 This driver supports hardware monitoring for various PMBus compliant devices.
  92 It supports voltage, current, power, and temperature sensors as supported
  93 by the device.
  94
  95 Each monitored channel has its own high and low limits, plus a critical
  96 limit.
  97
  98 Fan support will be added in a later version of this driver.
  99
 100
 101 Usage Notes
 102 -----------
 103
 104 This driver does not probe for PMBus devices, since there is no register
 105 which can be safely used to identify the chip (The MFG_ID register is not
 106 supported by all chips), and since there is no well defined address range for
 107 PMBus devices. You will have to instantiate the devices explicitly.
 108
 109 Example: the following will load the driver for an LTC2978 at address 0x60
 110 on I2C bus #1::
 111
 112         $ modprobe pmbus
 113         $ echo ltc2978 0x60 > /sys/bus/i2c/devices/i2c-1/new_device
 114
 115
 116 Platform data support
 117 ---------------------
 118
 119 Support for additional PMBus chips can be added by defining chip parameters in
 120 a new chip specific driver file. For example, (untested) code to add support for
 121 Emerson DS1200 power modules might look as follows::
 122
 123   static struct pmbus_driver_info ds1200_info = {
 124         .pages = 1,
 125         /* Note: All other sensors are in linear mode */
 126         .direct[PSC_VOLTAGE_OUT] = true,
 127         .direct[PSC_TEMPERATURE] = true,
 128         .direct[PSC_CURRENT_OUT] = true,
 129         .m[PSC_VOLTAGE_IN] = 1,
 130         .b[PSC_VOLTAGE_IN] = 0,
 131         .R[PSC_VOLTAGE_IN] = 3,
 132         .m[PSC_VOLTAGE_OUT] = 1,
 133         .b[PSC_VOLTAGE_OUT] = 0,
 134         .R[PSC_VOLTAGE_OUT] = 3,
 135         .m[PSC_TEMPERATURE] = 1,
 136         .b[PSC_TEMPERATURE] = 0,
 137         .R[PSC_TEMPERATURE] = 3,
 138         .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT
 139                    | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 140                    | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 141                    | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT
 142                    | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
 143                    | PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12,
 144   };
 145
 146   static int ds1200_probe(struct i2c_client *client)
 147   {
 148         return pmbus_do_probe(client, &ds1200_info);
 149   }
 150
 151   static const struct i2c_device_id ds1200_id[] = {
 152         {"ds1200", 0},
 153         {}
 154   };
 155
 156   MODULE_DEVICE_TABLE(i2c, ds1200_id);
 157
 158   /* This is the driver that will be inserted */
 159   static struct i2c_driver ds1200_driver = {
 160         .driver = {
 161                    .name = "ds1200",
 162                    },
 163         .probe_new = ds1200_probe,
 164         .id_table = ds1200_id,
 165   };
 166
 167   static int __init ds1200_init(void)
 168   {
 169         return i2c_add_driver(&ds1200_driver);
 170   }
 171
 172   static void __exit ds1200_exit(void)
 173   {
 174         i2c_del_driver(&ds1200_driver);
 175   }
 176
 177
 178 Sysfs entries
 179 -------------
 180
 181 When probing the chip, the driver identifies which PMBus registers are
 182 supported, and determines available sensors from this information.
 183 Attribute files only exist if respective sensors are supported by the chip.
 184 Labels are provided to inform the user about the sensor associated with
 185 a given sysfs entry.
 186
 187 The following attributes are supported. Limits are read-write; all other
 188 attributes are read-only.
 189
 190 ======================= ========================================================
 191 inX_input               Measured voltage. From READ_VIN or READ_VOUT register.
 192 inX_min                 Minimum Voltage.
 193                         From VIN_UV_WARN_LIMIT or VOUT_UV_WARN_LIMIT register.
 194 inX_max                 Maximum voltage.
 195                         From VIN_OV_WARN_LIMIT or VOUT_OV_WARN_LIMIT register.
 196 inX_lcrit               Critical minimum Voltage.
 197                         From VIN_UV_FAULT_LIMIT or VOUT_UV_FAULT_LIMIT register.
 198 inX_crit                Critical maximum voltage.
 199                         From VIN_OV_FAULT_LIMIT or VOUT_OV_FAULT_LIMIT register.
 200 inX_min_alarm           Voltage low alarm. From VOLTAGE_UV_WARNING status.
 201 inX_max_alarm           Voltage high alarm. From VOLTAGE_OV_WARNING status.
 202 inX_lcrit_alarm         Voltage critical low alarm.
 203                         From VOLTAGE_UV_FAULT status.
 204 inX_crit_alarm          Voltage critical high alarm.
 205                         From VOLTAGE_OV_FAULT status.
 206 inX_label               "vin", "vcap", or "voutY"
 207 inX_rated_min           Minimum rated voltage.
 208                         From MFR_VIN_MIN or MFR_VOUT_MIN register.
 209 inX_rated_max           Maximum rated voltage.
 210                         From MFR_VIN_MAX or MFR_VOUT_MAX register.
 211
 212 currX_input             Measured current. From READ_IIN or READ_IOUT register.
 213 currX_max               Maximum current.
 214                         From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT register.
 215 currX_lcrit             Critical minimum output current.
 216                         From IOUT_UC_FAULT_LIMIT register.
 217 currX_crit              Critical maximum current.
 218                         From IIN_OC_FAULT_LIMIT or IOUT_OC_FAULT_LIMIT register.
 219 currX_alarm             Current high alarm.
 220                         From IIN_OC_WARNING or IOUT_OC_WARNING status.
 221 currX_max_alarm         Current high alarm.
 222                         From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT status.
 223 currX_lcrit_alarm       Output current critical low alarm.
 224                         From IOUT_UC_FAULT status.
 225 currX_crit_alarm        Current critical high alarm.
 226                         From IIN_OC_FAULT or IOUT_OC_FAULT status.
 227 currX_label             "iin", "iinY", "iinY.Z", "ioutY", or "ioutY.Z",
 228                         where Y reflects the page number and Z reflects the
 229                         phase.
 230 currX_rated_max         Maximum rated current.
 231                         From MFR_IIN_MAX or MFR_IOUT_MAX register.
 232
 233 powerX_input            Measured power. From READ_PIN or READ_POUT register.
 234 powerX_cap              Output power cap. From POUT_MAX register.
 235 powerX_max              Power limit. From PIN_OP_WARN_LIMIT or
 236                         POUT_OP_WARN_LIMIT register.
 237 powerX_crit             Critical output power limit.
 238                         From POUT_OP_FAULT_LIMIT register.
 239 powerX_alarm            Power high alarm.
 240                         From PIN_OP_WARNING or POUT_OP_WARNING status.
 241 powerX_crit_alarm       Output power critical high alarm.
 242                         From POUT_OP_FAULT status.
 243 powerX_label            "pin", "pinY", "pinY.Z", "poutY", or "poutY.Z",
 244                         where Y reflects the page number and Z reflects the
 245                         phase.
 246 powerX_rated_max        Maximum rated power.
 247                         From MFR_PIN_MAX or MFR_POUT_MAX register.
 248
 249 tempX_input             Measured temperature.
 250                         From READ_TEMPERATURE_X register.
 251 tempX_min               Minimum temperature. From UT_WARN_LIMIT register.
 252 tempX_max               Maximum temperature. From OT_WARN_LIMIT register.
 253 tempX_lcrit             Critical low temperature.
 254                         From UT_FAULT_LIMIT register.
 255 tempX_crit              Critical high temperature.
 256                         From OT_FAULT_LIMIT register.
 257 tempX_min_alarm         Chip temperature low alarm. Set by comparing
 258                         READ_TEMPERATURE_X with UT_WARN_LIMIT if
 259                         TEMP_UT_WARNING status is set.
 260 tempX_max_alarm         Chip temperature high alarm. Set by comparing
 261                         READ_TEMPERATURE_X with OT_WARN_LIMIT if
 262                         TEMP_OT_WARNING status is set.
 263 tempX_lcrit_alarm       Chip temperature critical low alarm. Set by comparing
 264                         READ_TEMPERATURE_X with UT_FAULT_LIMIT if
 265                         TEMP_UT_FAULT status is set.
 266 tempX_crit_alarm        Chip temperature critical high alarm. Set by comparing
 267                         READ_TEMPERATURE_X with OT_FAULT_LIMIT if
 268                         TEMP_OT_FAULT status is set.
 269 tempX_rated_min         Minimum rated temperature.
 270                         From MFR_TAMBIENT_MIN register.
 271 tempX_rated_max         Maximum rated temperature.
 272                         From MFR_TAMBIENT_MAX, MFR_MAX_TEMP_1, MFR_MAX_TEMP_2 or
 273                         MFR_MAX_TEMP_3 register.
 274 ======================= ========================================================