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         http://www.onsemi.com/pub_link/Collateral/ADP4000-D.PDF
  25
  26         http://www.onsemi.com/pub_link/Collateral/NCP4200-D.PDF
  27
  28         http://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         http://www.ti.com/lit/gpn/tps40400
  57
  58         http://www.ti.com/lit/gpn/tps544b20
  59
  60         http://www.ti.com/lit/gpn/tps544b25
  61
  62         http://www.ti.com/lit/gpn/tps544c20
  63
  64         http://www.ti.com/lit/gpn/tps544c25
  65
  66   * Generic PMBus devices
  67
  68     Prefix: 'pmbus'
  69
  70     Addresses scanned: -
  71
  72     Datasheet: n.a.
  73
  74
  75 Author: Guenter Roeck <linux@roeck-us.net>
  76
  77
  78 Description
  79 -----------
  80
  81 This driver supports hardware monitoring for various PMBus compliant devices.
  82 It supports voltage, current, power, and temperature sensors as supported
  83 by the device.
  84
  85 Each monitored channel has its own high and low limits, plus a critical
  86 limit.
  87
  88 Fan support will be added in a later version of this driver.
  89
  90
  91 Usage Notes
  92 -----------
  93
  94 This driver does not probe for PMBus devices, since there is no register
  95 which can be safely used to identify the chip (The MFG_ID register is not
  96 supported by all chips), and since there is no well defined address range for
  97 PMBus devices. You will have to instantiate the devices explicitly.
  98
  99 Example: the following will load the driver for an LTC2978 at address 0x60
 100 on I2C bus #1::
 101
 102         $ modprobe pmbus
 103         $ echo ltc2978 0x60 > /sys/bus/i2c/devices/i2c-1/new_device
 104
 105
 106 Platform data support
 107 ---------------------
 108
 109 Support for additional PMBus chips can be added by defining chip parameters in
 110 a new chip specific driver file. For example, (untested) code to add support for
 111 Emerson DS1200 power modules might look as follows::
 112
 113   static struct pmbus_driver_info ds1200_info = {
 114         .pages = 1,
 115         /* Note: All other sensors are in linear mode */
 116         .direct[PSC_VOLTAGE_OUT] = true,
 117         .direct[PSC_TEMPERATURE] = true,
 118         .direct[PSC_CURRENT_OUT] = true,
 119         .m[PSC_VOLTAGE_IN] = 1,
 120         .b[PSC_VOLTAGE_IN] = 0,
 121         .R[PSC_VOLTAGE_IN] = 3,
 122         .m[PSC_VOLTAGE_OUT] = 1,
 123         .b[PSC_VOLTAGE_OUT] = 0,
 124         .R[PSC_VOLTAGE_OUT] = 3,
 125         .m[PSC_TEMPERATURE] = 1,
 126         .b[PSC_TEMPERATURE] = 0,
 127         .R[PSC_TEMPERATURE] = 3,
 128         .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT
 129                    | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 130                    | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 131                    | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT
 132                    | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
 133                    | PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12,
 134   };
 135
 136   static int ds1200_probe(struct i2c_client *client,
 137                           const struct i2c_device_id *id)
 138   {
 139         return pmbus_do_probe(client, id, &ds1200_info);
 140   }
 141
 142   static int ds1200_remove(struct i2c_client *client)
 143   {
 144         return pmbus_do_remove(client);
 145   }
 146
 147   static const struct i2c_device_id ds1200_id[] = {
 148         {"ds1200", 0},
 149         {}
 150   };
 151
 152   MODULE_DEVICE_TABLE(i2c, ds1200_id);
 153
 154   /* This is the driver that will be inserted */
 155   static struct i2c_driver ds1200_driver = {
 156         .driver = {
 157                    .name = "ds1200",
 158                    },
 159         .probe = ds1200_probe,
 160         .remove = ds1200_remove,
 161         .id_table = ds1200_id,
 162   };
 163
 164   static int __init ds1200_init(void)
 165   {
 166         return i2c_add_driver(&ds1200_driver);
 167   }
 168
 169   static void __exit ds1200_exit(void)
 170   {
 171         i2c_del_driver(&ds1200_driver);
 172   }
 173
 174
 175 Sysfs entries
 176 -------------
 177
 178 When probing the chip, the driver identifies which PMBus registers are
 179 supported, and determines available sensors from this information.
 180 Attribute files only exist if respective sensors are supported by the chip.
 181 Labels are provided to inform the user about the sensor associated with
 182 a given sysfs entry.
 183
 184 The following attributes are supported. Limits are read-write; all other
 185 attributes are read-only.
 186
 187 ======================= ========================================================
 188 inX_input               Measured voltage. From READ_VIN or READ_VOUT register.
 189 inX_min                 Minimum Voltage.
 190                         From VIN_UV_WARN_LIMIT or VOUT_UV_WARN_LIMIT register.
 191 inX_max                 Maximum voltage.
 192                         From VIN_OV_WARN_LIMIT or VOUT_OV_WARN_LIMIT register.
 193 inX_lcrit               Critical minimum Voltage.
 194                         From VIN_UV_FAULT_LIMIT or VOUT_UV_FAULT_LIMIT register.
 195 inX_crit                Critical maximum voltage.
 196                         From VIN_OV_FAULT_LIMIT or VOUT_OV_FAULT_LIMIT register.
 197 inX_min_alarm           Voltage low alarm. From VOLTAGE_UV_WARNING status.
 198 inX_max_alarm           Voltage high alarm. From VOLTAGE_OV_WARNING status.
 199 inX_lcrit_alarm         Voltage critical low alarm.
 200                         From VOLTAGE_UV_FAULT status.
 201 inX_crit_alarm          Voltage critical high alarm.
 202                         From VOLTAGE_OV_FAULT status.
 203 inX_label               "vin", "vcap", or "voutY"
 204
 205 currX_input             Measured current. From READ_IIN or READ_IOUT register.
 206 currX_max               Maximum current.
 207                         From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT register.
 208 currX_lcrit             Critical minimum output current.
 209                         From IOUT_UC_FAULT_LIMIT register.
 210 currX_crit              Critical maximum current.
 211                         From IIN_OC_FAULT_LIMIT or IOUT_OC_FAULT_LIMIT register.
 212 currX_alarm             Current high alarm.
 213                         From IIN_OC_WARNING or IOUT_OC_WARNING status.
 214 currX_max_alarm         Current high alarm.
 215                         From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT status.
 216 currX_lcrit_alarm       Output current critical low alarm.
 217                         From IOUT_UC_FAULT status.
 218 currX_crit_alarm        Current critical high alarm.
 219                         From IIN_OC_FAULT or IOUT_OC_FAULT status.
 220 currX_label             "iin" or "ioutY"
 221
 222 powerX_input            Measured power. From READ_PIN or READ_POUT register.
 223 powerX_cap              Output power cap. From POUT_MAX register.
 224 powerX_max              Power limit. From PIN_OP_WARN_LIMIT or
 225                         POUT_OP_WARN_LIMIT register.
 226 powerX_crit             Critical output power limit.
 227                         From POUT_OP_FAULT_LIMIT register.
 228 powerX_alarm            Power high alarm.
 229                         From PIN_OP_WARNING or POUT_OP_WARNING status.
 230 powerX_crit_alarm       Output power critical high alarm.
 231                         From POUT_OP_FAULT status.
 232 powerX_label            "pin" or "poutY"
 233
 234 tempX_input             Measured temperature.
 235                         From READ_TEMPERATURE_X register.
 236 tempX_min               Mimimum temperature. From UT_WARN_LIMIT register.
 237 tempX_max               Maximum temperature. From OT_WARN_LIMIT register.
 238 tempX_lcrit             Critical low temperature.
 239                         From UT_FAULT_LIMIT register.
 240 tempX_crit              Critical high temperature.
 241                         From OT_FAULT_LIMIT register.
 242 tempX_min_alarm         Chip temperature low alarm. Set by comparing
 243                         READ_TEMPERATURE_X with UT_WARN_LIMIT if
 244                         TEMP_UT_WARNING status is set.
 245 tempX_max_alarm         Chip temperature high alarm. Set by comparing
 246                         READ_TEMPERATURE_X with OT_WARN_LIMIT if
 247                         TEMP_OT_WARNING status is set.
 248 tempX_lcrit_alarm       Chip temperature critical low alarm. Set by comparing
 249                         READ_TEMPERATURE_X with UT_FAULT_LIMIT if
 250                         TEMP_UT_FAULT status is set.
 251 tempX_crit_alarm        Chip temperature critical high alarm. Set by comparing
 252                         READ_TEMPERATURE_X with OT_FAULT_LIMIT if
 253                         TEMP_OT_FAULT status is set.
 254 ======================= ========================================================