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