Documentation/hwmon/pmbus.rst

   1 Kernel driver pmbus
   2 ===================
   3
   4 Supported chips:
   5
   6   * Flex BMR310, BMR453, BMR454, BMR456, BMR457, BMR458, BMR480,
   7     BMR490, BMR491, BMR492
   8
   9     Prefixes: 'bmr310', 'bmr453', 'bmr454', 'bmr456', 'bmr457', 'bmr458', 'bmr480',
  10     'bmr490', 'bmr491', 'bmr492'
  11
  12     Addresses scanned: -
  13
  14     Datasheets:
  15
  16         https://flexpowermodules.com/products
  17
  18
  19   * ON Semiconductor ADP4000, NCP4200, NCP4208
  20
  21     Prefixes: 'adp4000', 'ncp4200', 'ncp4208'
  22
  23     Addresses scanned: -
  24
  25     Datasheets:
  26
  27         https://www.onsemi.com/pub_link/Collateral/ADP4000-D.PDF
  28
  29         https://www.onsemi.com/pub_link/Collateral/NCP4200-D.PDF
  30
  31         https://www.onsemi.com/pub_link/Collateral/JUNE%202009-%20REV.%200.PDF
  32
  33   * Lineage Power
  34
  35     Prefixes: 'mdt040', 'pdt003', 'pdt006', 'pdt012', 'udt020'
  36
  37     Addresses scanned: -
  38
  39     Datasheets:
  40
  41         http://www.lineagepower.com/oem/pdf/PDT003A0X.pdf
  42
  43         http://www.lineagepower.com/oem/pdf/PDT006A0X.pdf
  44
  45         http://www.lineagepower.com/oem/pdf/PDT012A0X.pdf
  46
  47         http://www.lineagepower.com/oem/pdf/UDT020A0X.pdf
  48
  49         http://www.lineagepower.com/oem/pdf/MDT040A0X.pdf
  50
  51   * Texas Instruments TPS40400, TPS544B20, TPS544B25, TPS544C20, TPS544C25
  52
  53     Prefixes: 'tps40400', 'tps544b20', 'tps544b25', 'tps544c20', 'tps544c25'
  54
  55     Addresses scanned: -
  56
  57     Datasheets:
  58
  59         https://www.ti.com/lit/gpn/tps40400
  60
  61         https://www.ti.com/lit/gpn/tps544b20
  62
  63         https://www.ti.com/lit/gpn/tps544b25
  64
  65         https://www.ti.com/lit/gpn/tps544c20
  66
  67         https://www.ti.com/lit/gpn/tps544c25
  68
  69   * Maxim MAX20796
  70
  71     Prefix: 'max20796'
  72
  73     Addresses scanned: -
  74
  75     Datasheet:
  76
  77         Not published
  78
  79   * Generic PMBus devices
  80
  81     Prefix: 'pmbus'
  82
  83     Addresses scanned: -
  84
  85     Datasheet: n.a.
  86
  87
  88 Author: Guenter Roeck <linux@roeck-us.net>
  89
  90
  91 Description
  92 -----------
  93
  94 This driver supports hardware monitoring for various PMBus compliant devices.
  95 It supports voltage, current, power, and temperature sensors as supported
  96 by the device.
  97
  98 Each monitored channel has its own high and low limits, plus a critical
  99 limit.
 100
 101 Fan support will be added in a later version of this driver.
 102
 103
 104 Usage Notes
 105 -----------
 106
 107 This driver does not probe for PMBus devices, since there is no register
 108 which can be safely used to identify the chip (The MFG_ID register is not
 109 supported by all chips), and since there is no well defined address range for
 110 PMBus devices. You will have to instantiate the devices explicitly.
 111
 112 Example: the following will load the driver for an LTC2978 at address 0x60
 113 on I2C bus #1::
 114
 115         $ modprobe pmbus
 116         $ echo ltc2978 0x60 > /sys/bus/i2c/devices/i2c-1/new_device
 117
 118
 119 Platform data support
 120 ---------------------
 121
 122 Support for additional PMBus chips can be added by defining chip parameters in
 123 a new chip specific driver file. For example, (untested) code to add support for
 124 Emerson DS1200 power modules might look as follows::
 125
 126   static struct pmbus_driver_info ds1200_info = {
 127         .pages = 1,
 128         /* Note: All other sensors are in linear mode */
 129         .direct[PSC_VOLTAGE_OUT] = true,
 130         .direct[PSC_TEMPERATURE] = true,
 131         .direct[PSC_CURRENT_OUT] = true,
 132         .m[PSC_VOLTAGE_IN] = 1,
 133         .b[PSC_VOLTAGE_IN] = 0,
 134         .R[PSC_VOLTAGE_IN] = 3,
 135         .m[PSC_VOLTAGE_OUT] = 1,
 136         .b[PSC_VOLTAGE_OUT] = 0,
 137         .R[PSC_VOLTAGE_OUT] = 3,
 138         .m[PSC_TEMPERATURE] = 1,
 139         .b[PSC_TEMPERATURE] = 0,
 140         .R[PSC_TEMPERATURE] = 3,
 141         .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT
 142                    | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 143                    | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 144                    | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT
 145                    | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
 146                    | PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12,
 147   };
 148
 149   static int ds1200_probe(struct i2c_client *client)
 150   {
 151         return pmbus_do_probe(client, &ds1200_info);
 152   }
 153
 154   static const struct i2c_device_id ds1200_id[] = {
 155         {"ds1200", 0},
 156         {}
 157   };
 158
 159   MODULE_DEVICE_TABLE(i2c, ds1200_id);
 160
 161   /* This is the driver that will be inserted */
 162   static struct i2c_driver ds1200_driver = {
 163         .driver = {
 164                    .name = "ds1200",
 165                    },
 166         .probe_new = ds1200_probe,
 167         .id_table = ds1200_id,
 168   };
 169
 170   static int __init ds1200_init(void)
 171   {
 172         return i2c_add_driver(&ds1200_driver);
 173   }
 174
 175   static void __exit ds1200_exit(void)
 176   {
 177         i2c_del_driver(&ds1200_driver);
 178   }
 179
 180
 181 Sysfs entries
 182 -------------
 183
 184 When probing the chip, the driver identifies which PMBus registers are
 185 supported, and determines available sensors from this information.
 186 Attribute files only exist if respective sensors are supported by the chip.
 187 Labels are provided to inform the user about the sensor associated with
 188 a given sysfs entry.
 189
 190 The following attributes are supported. Limits are read-write; all other
 191 attributes are read-only.
 192
 193 ======================= ========================================================
 194 inX_input               Measured voltage. From READ_VIN or READ_VOUT register.
 195 inX_min                 Minimum Voltage.
 196                         From VIN_UV_WARN_LIMIT or VOUT_UV_WARN_LIMIT register.
 197 inX_max                 Maximum voltage.
 198                         From VIN_OV_WARN_LIMIT or VOUT_OV_WARN_LIMIT register.
 199 inX_lcrit               Critical minimum Voltage.
 200                         From VIN_UV_FAULT_LIMIT or VOUT_UV_FAULT_LIMIT register.
 201 inX_crit                Critical maximum voltage.
 202                         From VIN_OV_FAULT_LIMIT or VOUT_OV_FAULT_LIMIT register.
 203 inX_min_alarm           Voltage low alarm. From VOLTAGE_UV_WARNING status.
 204 inX_max_alarm           Voltage high alarm. From VOLTAGE_OV_WARNING status.
 205 inX_lcrit_alarm         Voltage critical low alarm.
 206                         From VOLTAGE_UV_FAULT status.
 207 inX_crit_alarm          Voltage critical high alarm.
 208                         From VOLTAGE_OV_FAULT status.
 209 inX_label               "vin", "vcap", or "voutY"
 210 inX_rated_min           Minimum rated voltage.
 211                         From MFR_VIN_MIN or MFR_VOUT_MIN register.
 212 inX_rated_max           Maximum rated voltage.
 213                         From MFR_VIN_MAX or MFR_VOUT_MAX register.
 214
 215 currX_input             Measured current. From READ_IIN or READ_IOUT register.
 216 currX_max               Maximum current.
 217                         From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT register.
 218 currX_lcrit             Critical minimum output current.
 219                         From IOUT_UC_FAULT_LIMIT register.
 220 currX_crit              Critical maximum current.
 221                         From IIN_OC_FAULT_LIMIT or IOUT_OC_FAULT_LIMIT register.
 222 currX_alarm             Current high alarm.
 223                         From IIN_OC_WARNING or IOUT_OC_WARNING status.
 224 currX_max_alarm         Current high alarm.
 225                         From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT status.
 226 currX_lcrit_alarm       Output current critical low alarm.
 227                         From IOUT_UC_FAULT status.
 228 currX_crit_alarm        Current critical high alarm.
 229                         From IIN_OC_FAULT or IOUT_OC_FAULT status.
 230 currX_label             "iin", "iinY", "iinY.Z", "ioutY", or "ioutY.Z",
 231                         where Y reflects the page number and Z reflects the
 232                         phase.
 233 currX_rated_max         Maximum rated current.
 234                         From MFR_IIN_MAX or MFR_IOUT_MAX register.
 235
 236 powerX_input            Measured power. From READ_PIN or READ_POUT register.
 237 powerX_cap              Output power cap. From POUT_MAX register.
 238 powerX_max              Power limit. From PIN_OP_WARN_LIMIT or
 239                         POUT_OP_WARN_LIMIT register.
 240 powerX_crit             Critical output power limit.
 241                         From POUT_OP_FAULT_LIMIT register.
 242 powerX_alarm            Power high alarm.
 243                         From PIN_OP_WARNING or POUT_OP_WARNING status.
 244 powerX_crit_alarm       Output power critical high alarm.
 245                         From POUT_OP_FAULT status.
 246 powerX_label            "pin", "pinY", "pinY.Z", "poutY", or "poutY.Z",
 247                         where Y reflects the page number and Z reflects the
 248                         phase.
 249 powerX_rated_max        Maximum rated power.
 250                         From MFR_PIN_MAX or MFR_POUT_MAX register.
 251
 252 tempX_input             Measured temperature.
 253                         From READ_TEMPERATURE_X register.
 254 tempX_min               Minimum temperature. From UT_WARN_LIMIT register.
 255 tempX_max               Maximum temperature. From OT_WARN_LIMIT register.
 256 tempX_lcrit             Critical low temperature.
 257                         From UT_FAULT_LIMIT register.
 258 tempX_crit              Critical high temperature.
 259                         From OT_FAULT_LIMIT register.
 260 tempX_min_alarm         Chip temperature low alarm. Set by comparing
 261                         READ_TEMPERATURE_X with UT_WARN_LIMIT if
 262                         TEMP_UT_WARNING status is set.
 263 tempX_max_alarm         Chip temperature high alarm. Set by comparing
 264                         READ_TEMPERATURE_X with OT_WARN_LIMIT if
 265                         TEMP_OT_WARNING status is set.
 266 tempX_lcrit_alarm       Chip temperature critical low alarm. Set by comparing
 267                         READ_TEMPERATURE_X with UT_FAULT_LIMIT if
 268                         TEMP_UT_FAULT status is set.
 269 tempX_crit_alarm        Chip temperature critical high alarm. Set by comparing
 270                         READ_TEMPERATURE_X with OT_FAULT_LIMIT if
 271                         TEMP_OT_FAULT status is set.
 272 tempX_rated_min         Minimum rated temperature.
 273                         From MFR_TAMBIENT_MIN register.
 274 tempX_rated_max         Maximum rated temperature.
 275                         From MFR_TAMBIENT_MAX, MFR_MAX_TEMP_1, MFR_MAX_TEMP_2 or
 276                         MFR_MAX_TEMP_3 register.
 277 ======================= ========================================================