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Based on kernel version 3.3. Page generated on 2012-03-23 21:32 EST.

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