[linux-2.6-block.git] / Documentation / hwmon / pmbus

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

Supported chips:
  * Ericsson BMR453, BMR454
    Prefixes: 'bmr453', 'bmr454'
    Addresses scanned: -
    Datasheet:
 http://archive.ericsson.net/service/internet/picov/get?DocNo=28701-EN/LZT146395
  * ON Semiconductor ADP4000, NCP4200, NCP4208
    Prefixes: 'adp4000', 'ncp4200', 'ncp4208'
    Addresses scanned: -
    Datasheets:
	http://www.onsemi.com/pub_link/Collateral/ADP4000-D.PDF
	http://www.onsemi.com/pub_link/Collateral/NCP4200-D.PDF
	http://www.onsemi.com/pub_link/Collateral/JUNE%202009-%20REV.%200.PDF
  * Lineage Power
    Prefixes: 'mdt040', 'pdt003', 'pdt006', 'pdt012', 'udt020'
    Addresses scanned: -
    Datasheets:
	http://www.lineagepower.com/oem/pdf/PDT003A0X.pdf
	http://www.lineagepower.com/oem/pdf/PDT006A0X.pdf
	http://www.lineagepower.com/oem/pdf/PDT012A0X.pdf
	http://www.lineagepower.com/oem/pdf/UDT020A0X.pdf
	http://www.lineagepower.com/oem/pdf/MDT040A0X.pdf
  * Texas Instruments TPS40400
    Prefixes: 'tps40400'
    Addresses scanned: -
    Datasheets:
	http://www.ti.com/lit/gpn/tps40400
  * Generic PMBus devices
    Prefix: 'pmbus'
    Addresses scanned: -
    Datasheet: n.a.

Author: Guenter Roeck <linux@roeck-us.net>


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 supported 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_max_alarm		Current high alarm.
			From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT 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 "ioutY"

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 temperature.
			From READ_TEMPERATURE_X register.
tempX_min		Mimimum temperature. From UT_WARN_LIMIT register.
tempX_max		Maximum temperature. From OT_WARN_LIMIT register.
tempX_lcrit		Critical low temperature.
			From UT_FAULT_LIMIT register.
tempX_crit		Critical high temperature.
			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.
Commit	Line	Data
44f5a408 GR	1	Kernel driver pmbus
	2	====================
	3
	4	Supported chips:
443830f6 GR	5	* Ericsson BMR453, BMR454
443830f6 GR	6	Prefixes: 'bmr453', 'bmr454'
44f5a408 GR	7	Addresses scanned: -
	8	Datasheet:
	9	http://archive.ericsson.net/service/internet/picov/get?DocNo=28701-EN/LZT146395
e0455e38 GR	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
bc365a7f	17	* Lineage Power
21633409	18	Prefixes: 'mdt040', 'pdt003', 'pdt006', 'pdt012', 'udt020'
bc365a7f GR	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
21633409	25	http://www.lineagepower.com/oem/pdf/MDT040A0X.pdf
a8bfeceb ZRNCB	26	* Texas Instruments TPS40400
a8bfeceb ZRNCB	27	Prefixes: 'tps40400'
c5f35c9d GR	28	Addresses scanned: -
	29	Datasheets:
	30	http://www.ti.com/lit/gpn/tps40400
44f5a408 GR	31	* Generic PMBus devices
	32	Prefix: 'pmbus'
	33	Addresses scanned: -
	34	Datasheet: n.a.
	35
e3333e57	36	Author: Guenter Roeck <linux@roeck-us.net>
44f5a408 GR	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.
02582e9b	140	Attribute files only exist if respective sensors are supported by the chip.
44f5a408 GR	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.
25985edc	148	inX_min Minimum Voltage.
44f5a408 GR	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.
25985edc	152	inX_lcrit Critical minimum Voltage.
44f5a408 GR	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.
25985edc	167	currX_lcrit Critical minimum output current.
44f5a408 GR	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.
180b3d88 GR	173	currX_max_alarm Current high alarm.
180b3d88 GR	174	From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT status.
44f5a408 GR	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.
180b3d88	179	currX_label "iin" or "ioutY"
44f5a408 GR	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
180b3d88	193	tempX_input Measured temperature.
44f5a408	194	From READ_TEMPERATURE_X register.
180b3d88 GR	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.
44f5a408	198	From UT_FAULT_LIMIT register.
180b3d88	199	tempX_crit Critical high temperature.
44f5a408 GR	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.