Documentation/hwmon/pmbus - arm/linux-arm64-legacy - Git at Google

 Kernel driver pmbus
 ====================

 Supported chips:
   * Ericsson BMR45X series
     DC/DC Converter
     Prefixes: 'bmr450', 'bmr451', 'bmr453', 'bmr454'
     Addresses scanned: -
     Datasheet:
  http://archive.ericsson.net/service/internet/picov/get?DocNo=28701-EN/LZT146395
   * Linear Technology LTC2978
     Octal PMBus Power Supply Monitor and Controller
     Prefix: 'ltc2978'
     Addresses scanned: -
     Datasheet: http://cds.linear.com/docs/Datasheet/2978fa.pdf
   * Maxim MAX16064
     Quad Power-Supply Controller
     Prefix: 'max16064'
     Addresses scanned: -
     Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX16064.pdf
   * Maxim MAX34440
     PMBus 6-Channel Power-Supply Manager
     Prefixes: 'max34440'
     Addresses scanned: -
     Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX34440.pdf
   * Maxim MAX34441
     PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller
     Prefixes: 'max34441'
     Addresses scanned: -
     Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX34441.pdf
   * Maxim MAX8688
     Digital Power-Supply Controller/Monitor
     Prefix: 'max8688'
     Addresses scanned: -
     Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8688.pdf
   * Generic PMBus devices
     Prefix: 'pmbus'
     Addresses scanned: -
     Datasheet: n.a.

 Author: Guenter Roeck <guenter.roeck@ericsson.com>


 Description
 -----------

 This driver supports hardware montoring for various PMBus compliant devices.
 It supports voltage, current, power, and temperature sensors as supported
 by the device.

 Each monitored channel has its own high and low limits, plus a critical
 limit.

 Fan support will be added in a later version of this driver.


 Usage Notes
 -----------

 This driver does not probe for PMBus devices, since there is no register
 which can be safely used to identify the chip (The MFG_ID register is not
 supported by all chips), and since there is no well defined address range for
 PMBus devices. You will have to instantiate the devices explicitly.

 Example: the following will load the driver for an LTC2978 at address 0x60
 on I2C bus #1:
 $ modprobe pmbus
 $ echo ltc2978 0x60 > /sys/bus/i2c/devices/i2c-1/new_device


 Platform data support
 ---------------------

 Support for additional PMBus chips can be added by defining chip parameters in
 a new chip specific driver file. For example, (untested) code to add support for
 Emerson DS1200 power modules might look as follows.

 static struct pmbus_driver_info ds1200_info = {
 	.pages = 1,
 	/* Note: All other sensors are in linear mode */
 	.direct[PSC_VOLTAGE_OUT] = true,
 	.direct[PSC_TEMPERATURE] = true,
 	.direct[PSC_CURRENT_OUT] = true,
 	.m[PSC_VOLTAGE_IN] = 1,
 	.b[PSC_VOLTAGE_IN] = 0,
 	.R[PSC_VOLTAGE_IN] = 3,
 	.m[PSC_VOLTAGE_OUT] = 1,
 	.b[PSC_VOLTAGE_OUT] = 0,
 	.R[PSC_VOLTAGE_OUT] = 3,
 	.m[PSC_TEMPERATURE] = 1,
 	.b[PSC_TEMPERATURE] = 0,
 	.R[PSC_TEMPERATURE] = 3,
 	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT
 		   | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
 		   | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
 		   | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT
 		   | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
 		   | PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12,
 };

 static int ds1200_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	return pmbus_do_probe(client, id, &ds1200_info);
 }

 static int ds1200_remove(struct i2c_client *client)
 {
 	return pmbus_do_remove(client);
 }

 static const struct i2c_device_id ds1200_id[] = {
 	{"ds1200", 0},
 	{}
 };

 MODULE_DEVICE_TABLE(i2c, ds1200_id);

 /* This is the driver that will be inserted */
 static struct i2c_driver ds1200_driver = {
 	.driver = {
 		   .name = "ds1200",
 		   },
 	.probe = ds1200_probe,
 	.remove = ds1200_remove,
 	.id_table = ds1200_id,
 };

 static int __init ds1200_init(void)
 {
 	return i2c_add_driver(&ds1200_driver);
 }

 static void __exit ds1200_exit(void)
 {
 	i2c_del_driver(&ds1200_driver);
 }


 Sysfs entries
 -------------

 When probing the chip, the driver identifies which PMBus registers are
 supported, and determines available sensors from this information.
 Attribute files only exist if respective sensors are suported by the chip.
 Labels are provided to inform the user about the sensor associated with
 a given sysfs entry.

 The following attributes are supported. Limits are read-write; all other
 attributes are read-only.

 inX_input		Measured voltage. From READ_VIN or READ_VOUT register.
 inX_min			Minimum Voltage.
 			From VIN_UV_WARN_LIMIT or VOUT_UV_WARN_LIMIT register.
 inX_max			Maximum voltage.
 			From VIN_OV_WARN_LIMIT or VOUT_OV_WARN_LIMIT register.
 inX_lcrit		Critical minimum Voltage.
 			From VIN_UV_FAULT_LIMIT or VOUT_UV_FAULT_LIMIT register.
 inX_crit		Critical maximum voltage.
 			From VIN_OV_FAULT_LIMIT or VOUT_OV_FAULT_LIMIT register.
 inX_min_alarm		Voltage low alarm. From VOLTAGE_UV_WARNING status.
 inX_max_alarm		Voltage high alarm. From VOLTAGE_OV_WARNING status.
 inX_lcrit_alarm		Voltage critical low alarm.
 			From VOLTAGE_UV_FAULT status.
 inX_crit_alarm		Voltage critical high alarm.
 			From VOLTAGE_OV_FAULT status.
 inX_label		"vin", "vcap", or "voutY"

 currX_input		Measured current. From READ_IIN or READ_IOUT register.
 currX_max		Maximum current.
 			From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT register.
 currX_lcrit		Critical minimum output current.
 			From IOUT_UC_FAULT_LIMIT register.
 currX_crit		Critical maximum current.
 			From IIN_OC_FAULT_LIMIT or IOUT_OC_FAULT_LIMIT register.
 currX_alarm		Current high alarm.
 			From IIN_OC_WARNING or IOUT_OC_WARNING status.
 currX_lcrit_alarm	Output current critical low alarm.
 			From IOUT_UC_FAULT status.
 currX_crit_alarm	Current critical high alarm.
 			From IIN_OC_FAULT or IOUT_OC_FAULT status.
 currX_label		"iin" or "vinY"

 powerX_input		Measured power. From READ_PIN or READ_POUT register.
 powerX_cap		Output power cap. From POUT_MAX register.
 powerX_max		Power limit. From PIN_OP_WARN_LIMIT or
 			POUT_OP_WARN_LIMIT register.
 powerX_crit		Critical output power limit.
 			From POUT_OP_FAULT_LIMIT register.
 powerX_alarm		Power high alarm.
 			From PIN_OP_WARNING or POUT_OP_WARNING status.
 powerX_crit_alarm	Output power critical high alarm.
 			From POUT_OP_FAULT status.
 powerX_label		"pin" or "poutY"

 tempX_input		Measured tempererature.
 			From READ_TEMPERATURE_X register.
 tempX_min		Mimimum tempererature. From UT_WARN_LIMIT register.
 tempX_max		Maximum tempererature. From OT_WARN_LIMIT register.
 tempX_lcrit		Critical low tempererature.
 			From UT_FAULT_LIMIT register.
 tempX_crit		Critical high tempererature.
 			From OT_FAULT_LIMIT register.
 tempX_min_alarm		Chip temperature low alarm. Set by comparing
 			READ_TEMPERATURE_X with UT_WARN_LIMIT if
 			TEMP_UT_WARNING status is set.
 tempX_max_alarm		Chip temperature high alarm. Set by comparing
 			READ_TEMPERATURE_X with OT_WARN_LIMIT if
 			TEMP_OT_WARNING status is set.
 tempX_lcrit_alarm	Chip temperature critical low alarm. Set by comparing
 			READ_TEMPERATURE_X with UT_FAULT_LIMIT if
 			TEMP_UT_FAULT status is set.
 tempX_crit_alarm	Chip temperature critical high alarm. Set by comparing
 			READ_TEMPERATURE_X with OT_FAULT_LIMIT if
 			TEMP_OT_FAULT status is set.
	Kernel driver pmbus
	====================

	Supported chips:
	* Ericsson BMR45X series
	DC/DC Converter
	Prefixes: 'bmr450', 'bmr451', 'bmr453', 'bmr454'
	Addresses scanned: -
	Datasheet:
	http://archive.ericsson.net/service/internet/picov/get?DocNo=28701-EN/LZT146395
	* Linear Technology LTC2978
	Octal PMBus Power Supply Monitor and Controller
	Prefix: 'ltc2978'
	Addresses scanned: -
	Datasheet: http://cds.linear.com/docs/Datasheet/2978fa.pdf
	* Maxim MAX16064
	Quad Power-Supply Controller
	Prefix: 'max16064'
	Addresses scanned: -
	Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX16064.pdf
	* Maxim MAX34440
	PMBus 6-Channel Power-Supply Manager
	Prefixes: 'max34440'
	Addresses scanned: -
	Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX34440.pdf
	* Maxim MAX34441
	PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller
	Prefixes: 'max34441'
	Addresses scanned: -
	Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX34441.pdf
	* Maxim MAX8688
	Digital Power-Supply Controller/Monitor
	Prefix: 'max8688'
	Addresses scanned: -
	Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8688.pdf
	* Generic PMBus devices
	Prefix: 'pmbus'
	Addresses scanned: -
	Datasheet: n.a.

	Author: Guenter Roeck <guenter.roeck@ericsson.com>


	Description
	-----------

	This driver supports hardware montoring for various PMBus compliant devices.
	It supports voltage, current, power, and temperature sensors as supported
	by the device.

	Each monitored channel has its own high and low limits, plus a critical
	limit.

	Fan support will be added in a later version of this driver.


	Usage Notes
	-----------

	This driver does not probe for PMBus devices, since there is no register
	which can be safely used to identify the chip (The MFG_ID register is not
	supported by all chips), and since there is no well defined address range for
	PMBus devices. You will have to instantiate the devices explicitly.

	Example: the following will load the driver for an LTC2978 at address 0x60
	on I2C bus #1:
	$ modprobe pmbus
	$ echo ltc2978 0x60 > /sys/bus/i2c/devices/i2c-1/new_device


	Platform data support
	---------------------

	Support for additional PMBus chips can be added by defining chip parameters in
	a new chip specific driver file. For example, (untested) code to add support for
	Emerson DS1200 power modules might look as follows.

	static struct pmbus_driver_info ds1200_info = {
	.pages = 1,
	/* Note: All other sensors are in linear mode */
	.direct[PSC_VOLTAGE_OUT] = true,
	.direct[PSC_TEMPERATURE] = true,
	.direct[PSC_CURRENT_OUT] = true,
	.m[PSC_VOLTAGE_IN] = 1,
	.b[PSC_VOLTAGE_IN] = 0,
	.R[PSC_VOLTAGE_IN] = 3,
	.m[PSC_VOLTAGE_OUT] = 1,
	.b[PSC_VOLTAGE_OUT] = 0,
	.R[PSC_VOLTAGE_OUT] = 3,
	.m[PSC_TEMPERATURE] = 1,
	.b[PSC_TEMPERATURE] = 0,
	.R[PSC_TEMPERATURE] = 3,
	.func[0] = PMBUS_HAVE_VIN \| PMBUS_HAVE_IIN \| PMBUS_HAVE_STATUS_INPUT
	\| PMBUS_HAVE_VOUT \| PMBUS_HAVE_STATUS_VOUT
	\| PMBUS_HAVE_IOUT \| PMBUS_HAVE_STATUS_IOUT
	\| PMBUS_HAVE_PIN \| PMBUS_HAVE_POUT
	\| PMBUS_HAVE_TEMP \| PMBUS_HAVE_STATUS_TEMP
	\| PMBUS_HAVE_FAN12 \| PMBUS_HAVE_STATUS_FAN12,
	};

	static int ds1200_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	return pmbus_do_probe(client, id, &ds1200_info);
	}

	static int ds1200_remove(struct i2c_client *client)
	{
	return pmbus_do_remove(client);
	}

	static const struct i2c_device_id ds1200_id[] = {
	{"ds1200", 0},
	{}
	};

	MODULE_DEVICE_TABLE(i2c, ds1200_id);

	/* This is the driver that will be inserted */
	static struct i2c_driver ds1200_driver = {
	.driver = {
	.name = "ds1200",
	},
	.probe = ds1200_probe,
	.remove = ds1200_remove,
	.id_table = ds1200_id,
	};

	static int __init ds1200_init(void)
	{
	return i2c_add_driver(&ds1200_driver);
	}

	static void __exit ds1200_exit(void)
	{
	i2c_del_driver(&ds1200_driver);
	}


	Sysfs entries
	-------------

	When probing the chip, the driver identifies which PMBus registers are
	supported, and determines available sensors from this information.
	Attribute files only exist if respective sensors are suported by the chip.
	Labels are provided to inform the user about the sensor associated with
	a given sysfs entry.

	The following attributes are supported. Limits are read-write; all other
	attributes are read-only.

	inX_input Measured voltage. From READ_VIN or READ_VOUT register.
	inX_min Minimum Voltage.
	From VIN_UV_WARN_LIMIT or VOUT_UV_WARN_LIMIT register.
	inX_max Maximum voltage.
	From VIN_OV_WARN_LIMIT or VOUT_OV_WARN_LIMIT register.
	inX_lcrit Critical minimum Voltage.
	From VIN_UV_FAULT_LIMIT or VOUT_UV_FAULT_LIMIT register.
	inX_crit Critical maximum voltage.
	From VIN_OV_FAULT_LIMIT or VOUT_OV_FAULT_LIMIT register.
	inX_min_alarm Voltage low alarm. From VOLTAGE_UV_WARNING status.
	inX_max_alarm Voltage high alarm. From VOLTAGE_OV_WARNING status.
	inX_lcrit_alarm Voltage critical low alarm.
	From VOLTAGE_UV_FAULT status.
	inX_crit_alarm Voltage critical high alarm.
	From VOLTAGE_OV_FAULT status.
	inX_label "vin", "vcap", or "voutY"

	currX_input Measured current. From READ_IIN or READ_IOUT register.
	currX_max Maximum current.
	From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT register.
	currX_lcrit Critical minimum output current.
	From IOUT_UC_FAULT_LIMIT register.
	currX_crit Critical maximum current.
	From IIN_OC_FAULT_LIMIT or IOUT_OC_FAULT_LIMIT register.
	currX_alarm Current high alarm.
	From IIN_OC_WARNING or IOUT_OC_WARNING status.
	currX_lcrit_alarm Output current critical low alarm.
	From IOUT_UC_FAULT status.
	currX_crit_alarm Current critical high alarm.
	From IIN_OC_FAULT or IOUT_OC_FAULT status.
	currX_label "iin" or "vinY"

	powerX_input Measured power. From READ_PIN or READ_POUT register.
	powerX_cap Output power cap. From POUT_MAX register.
	powerX_max Power limit. From PIN_OP_WARN_LIMIT or
	POUT_OP_WARN_LIMIT register.
	powerX_crit Critical output power limit.
	From POUT_OP_FAULT_LIMIT register.
	powerX_alarm Power high alarm.
	From PIN_OP_WARNING or POUT_OP_WARNING status.
	powerX_crit_alarm Output power critical high alarm.
	From POUT_OP_FAULT status.
	powerX_label "pin" or "poutY"

	tempX_input Measured tempererature.
	From READ_TEMPERATURE_X register.
	tempX_min Mimimum tempererature. From UT_WARN_LIMIT register.
	tempX_max Maximum tempererature. From OT_WARN_LIMIT register.
	tempX_lcrit Critical low tempererature.
	From UT_FAULT_LIMIT register.
	tempX_crit Critical high tempererature.
	From OT_FAULT_LIMIT register.
	tempX_min_alarm Chip temperature low alarm. Set by comparing
	READ_TEMPERATURE_X with UT_WARN_LIMIT if
	TEMP_UT_WARNING status is set.
	tempX_max_alarm Chip temperature high alarm. Set by comparing
	READ_TEMPERATURE_X with OT_WARN_LIMIT if
	TEMP_OT_WARNING status is set.
	tempX_lcrit_alarm Chip temperature critical low alarm. Set by comparing
	READ_TEMPERATURE_X with UT_FAULT_LIMIT if
	TEMP_UT_FAULT status is set.
	tempX_crit_alarm Chip temperature critical high alarm. Set by comparing
	READ_TEMPERATURE_X with OT_FAULT_LIMIT if
	TEMP_OT_FAULT status is set.