Documentation/hwmon/pmbus

   1 Kernel driver pmbus
   2 ====================
   3
   4 Supported chips:
   5   * Ericsson BMR453, BMR454
   6     Prefixes: 'bmr453', 'bmr454'
   7     Addresses scanned: -
   8     Datasheet:
   9  http://archive.ericsson.net/service/internet/picov/get?DocNo=28701-EN/LZT146395
  10   * ON Semiconductor ADP4000, NCP4200, NCP4208
  11     Prefixes: 'adp4000', 'ncp4200', 'ncp4208'
  12     Addresses scanned: -
  13     Datasheets:
  14         http://www.onsemi.com/pub_link/Collateral/ADP4000-D.PDF
  15         http://www.onsemi.com/pub_link/Collateral/NCP4200-D.PDF
  16         http://www.onsemi.com/pub_link/Collateral/JUNE%202009-%20REV.%200.PDF
  17   * Lineage Power
  18     Prefixes: 'mdt040', 'pdt003', 'pdt006', 'pdt012', 'udt020'
  19     Addresses scanned: -
  20     Datasheets:
  21         http://www.lineagepower.com/oem/pdf/PDT003A0X.pdf
  22         http://www.lineagepower.com/oem/pdf/PDT006A0X.pdf
  23         http://www.lineagepower.com/oem/pdf/PDT012A0X.pdf
  24         http://www.lineagepower.com/oem/pdf/UDT020A0X.pdf
  25         http://www.lineagepower.com/oem/pdf/MDT040A0X.pdf
  26   * Texas Instruments TPS40400, TPS40422
  27     Prefixes: 'tps40400', 'tps40422'
  28     Addresses scanned: -
  29     Datasheets:
  30         http://www.ti.com/lit/gpn/tps40400
  31         http://www.ti.com/lit/gpn/tps40422
  32   * Generic PMBus devices
  33     Prefix: 'pmbus'
  34     Addresses scanned: -
  35     Datasheet: n.a.
  36
  37 Author: Guenter Roeck <linux@roeck-us.net>
  38
  39
  40 Description
  41 -----------
  42
  43 This driver supports hardware montoring for various PMBus compliant devices.
  44 It supports voltage, current, power, and temperature sensors as supported
  45 by the device.
  46
  47 Each monitored channel has its own high and low limits, plus a critical
  48 limit.
  49
  50 Fan support will be added in a later version of this driver.
  51
  52
  53 Usage Notes
  54 -----------
  55
  56 This driver does not probe for PMBus devices, since there is no register
  57 which can be safely used to identify the chip (The MFG_ID register is not
  58 supported by all chips), and since there is no well defined address range for
  59 PMBus devices. You will have to instantiate the devices explicitly.
  60
  61 Example: the following will load the driver for an LTC2978 at address 0x60
  62 on I2C bus #1:
  63 $ modprobe pmbus
  64 $ echo ltc2978 0x60 > /sys/bus/i2c/devices/i2c-1/new_device
  65
  66
  67 Platform data support
  68 ---------------------
  69
  70 Support for additional PMBus chips can be added by defining chip parameters in
  71 a new chip specific driver file. For example, (untested) code to add support for
  72 Emerson DS1200 power modules might look as follows.
  73
  74 static struct pmbus_driver_info ds1200_info = {
  75         .pages = 1,
  76         /* Note: All other sensors are in linear mode */
  77         .direct[PSC_VOLTAGE_OUT] = true,
  78         .direct[PSC_TEMPERATURE] = true,
  79         .direct[PSC_CURRENT_OUT] = true,
  80         .m[PSC_VOLTAGE_IN] = 1,
  81         .b[PSC_VOLTAGE_IN] = 0,
  82         .R[PSC_VOLTAGE_IN] = 3,
  83         .m[PSC_VOLTAGE_OUT] = 1,
  84         .b[PSC_VOLTAGE_OUT] = 0,
  85         .R[PSC_VOLTAGE_OUT] = 3,
  86         .m[PSC_TEMPERATURE] = 1,
  87         .b[PSC_TEMPERATURE] = 0,
  88         .R[PSC_TEMPERATURE] = 3,
  89         .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT
  90                    | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
  91                    | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
  92                    | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT
  93                    | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
  94                    | PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12,
  95 };
  96
  97 static int ds1200_probe(struct i2c_client *client,
  98                         const struct i2c_device_id *id)
  99 {
 100         return pmbus_do_probe(client, id, &ds1200_info);
 101 }
 102
 103 static int ds1200_remove(struct i2c_client *client)
 104 {
 105         return pmbus_do_remove(client);
 106 }
 107
 108 static const struct i2c_device_id ds1200_id[] = {
 109         {"ds1200", 0},
 110         {}
 111 };
 112
 113 MODULE_DEVICE_TABLE(i2c, ds1200_id);
 114
 115 /* This is the driver that will be inserted */
 116 static struct i2c_driver ds1200_driver = {
 117         .driver = {
 118                    .name = "ds1200",
 119                    },
 120         .probe = ds1200_probe,
 121         .remove = ds1200_remove,
 122         .id_table = ds1200_id,
 123 };
 124
 125 static int __init ds1200_init(void)
 126 {
 127         return i2c_add_driver(&ds1200_driver);
 128 }
 129
 130 static void __exit ds1200_exit(void)
 131 {
 132         i2c_del_driver(&ds1200_driver);
 133 }
 134
 135
 136 Sysfs entries
 137 -------------
 138
 139 When probing the chip, the driver identifies which PMBus registers are
 140 supported, and determines available sensors from this information.
 141 Attribute files only exist if respective sensors are supported by the chip.
 142 Labels are provided to inform the user about the sensor associated with
 143 a given sysfs entry.
 144
 145 The following attributes are supported. Limits are read-write; all other
 146 attributes are read-only.
 147
 148 inX_input               Measured voltage. From READ_VIN or READ_VOUT register.
 149 inX_min                 Minimum Voltage.
 150                         From VIN_UV_WARN_LIMIT or VOUT_UV_WARN_LIMIT register.
 151 inX_max                 Maximum voltage.
 152                         From VIN_OV_WARN_LIMIT or VOUT_OV_WARN_LIMIT register.
 153 inX_lcrit               Critical minimum Voltage.
 154                         From VIN_UV_FAULT_LIMIT or VOUT_UV_FAULT_LIMIT register.
 155 inX_crit                Critical maximum voltage.
 156                         From VIN_OV_FAULT_LIMIT or VOUT_OV_FAULT_LIMIT register.
 157 inX_min_alarm           Voltage low alarm. From VOLTAGE_UV_WARNING status.
 158 inX_max_alarm           Voltage high alarm. From VOLTAGE_OV_WARNING status.
 159 inX_lcrit_alarm         Voltage critical low alarm.
 160                         From VOLTAGE_UV_FAULT status.
 161 inX_crit_alarm          Voltage critical high alarm.
 162                         From VOLTAGE_OV_FAULT status.
 163 inX_label               "vin", "vcap", or "voutY"
 164
 165 currX_input             Measured current. From READ_IIN or READ_IOUT register.
 166 currX_max               Maximum current.
 167                         From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT register.
 168 currX_lcrit             Critical minimum output current.
 169                         From IOUT_UC_FAULT_LIMIT register.
 170 currX_crit              Critical maximum current.
 171                         From IIN_OC_FAULT_LIMIT or IOUT_OC_FAULT_LIMIT register.
 172 currX_alarm             Current high alarm.
 173                         From IIN_OC_WARNING or IOUT_OC_WARNING status.
 174 currX_max_alarm         Current high alarm.
 175                         From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT status.
 176 currX_lcrit_alarm       Output current critical low alarm.
 177                         From IOUT_UC_FAULT status.
 178 currX_crit_alarm        Current critical high alarm.
 179                         From IIN_OC_FAULT or IOUT_OC_FAULT status.
 180 currX_label             "iin" or "ioutY"
 181
 182 powerX_input            Measured power. From READ_PIN or READ_POUT register.
 183 powerX_cap              Output power cap. From POUT_MAX register.
 184 powerX_max              Power limit. From PIN_OP_WARN_LIMIT or
 185                         POUT_OP_WARN_LIMIT register.
 186 powerX_crit             Critical output power limit.
 187                         From POUT_OP_FAULT_LIMIT register.
 188 powerX_alarm            Power high alarm.
 189                         From PIN_OP_WARNING or POUT_OP_WARNING status.
 190 powerX_crit_alarm       Output power critical high alarm.
 191                         From POUT_OP_FAULT status.
 192 powerX_label            "pin" or "poutY"
 193
 194 tempX_input             Measured temperature.
 195                         From READ_TEMPERATURE_X register.
 196 tempX_min               Mimimum temperature. From UT_WARN_LIMIT register.
 197 tempX_max               Maximum temperature. From OT_WARN_LIMIT register.
 198 tempX_lcrit             Critical low temperature.
 199                         From UT_FAULT_LIMIT register.
 200 tempX_crit              Critical high temperature.
 201                         From OT_FAULT_LIMIT register.
 202 tempX_min_alarm         Chip temperature low alarm. Set by comparing
 203                         READ_TEMPERATURE_X with UT_WARN_LIMIT if
 204                         TEMP_UT_WARNING status is set.
 205 tempX_max_alarm         Chip temperature high alarm. Set by comparing
 206                         READ_TEMPERATURE_X with OT_WARN_LIMIT if
 207                         TEMP_OT_WARNING status is set.
 208 tempX_lcrit_alarm       Chip temperature critical low alarm. Set by comparing
 209                         READ_TEMPERATURE_X with UT_FAULT_LIMIT if
 210                         TEMP_UT_FAULT status is set.
 211 tempX_crit_alarm        Chip temperature critical high alarm. Set by comparing
 212                         READ_TEMPERATURE_X with OT_FAULT_LIMIT if
 213                         TEMP_OT_FAULT status is set.