1Kernel driver pmbus
2====================
3
4Supported 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, TPS544B20, TPS544B25, TPS544C20, TPS544C25
27    Prefixes: 'tps40400', 'tps544b20', 'tps544b25', 'tps544c20', 'tps544c25'
28    Addresses scanned: -
29    Datasheets:
30	http://www.ti.com/lit/gpn/tps40400
31	http://www.ti.com/lit/gpn/tps544b20
32	http://www.ti.com/lit/gpn/tps544b25
33	http://www.ti.com/lit/gpn/tps544c20
34	http://www.ti.com/lit/gpn/tps544c25
35  * Generic PMBus devices
36    Prefix: 'pmbus'
37    Addresses scanned: -
38    Datasheet: n.a.
39
40Author: Guenter Roeck <linux@roeck-us.net>
41
42
43Description
44-----------
45
46This driver supports hardware montoring for various PMBus compliant devices.
47It supports voltage, current, power, and temperature sensors as supported
48by the device.
49
50Each monitored channel has its own high and low limits, plus a critical
51limit.
52
53Fan support will be added in a later version of this driver.
54
55
56Usage Notes
57-----------
58
59This driver does not probe for PMBus devices, since there is no register
60which can be safely used to identify the chip (The MFG_ID register is not
61supported by all chips), and since there is no well defined address range for
62PMBus devices. You will have to instantiate the devices explicitly.
63
64Example: the following will load the driver for an LTC2978 at address 0x60
65on I2C bus #1:
66$ modprobe pmbus
67$ echo ltc2978 0x60 > /sys/bus/i2c/devices/i2c-1/new_device
68
69
70Platform data support
71---------------------
72
73Support for additional PMBus chips can be added by defining chip parameters in
74a new chip specific driver file. For example, (untested) code to add support for
75Emerson DS1200 power modules might look as follows.
76
77static struct pmbus_driver_info ds1200_info = {
78	.pages = 1,
79	/* Note: All other sensors are in linear mode */
80	.direct[PSC_VOLTAGE_OUT] = true,
81	.direct[PSC_TEMPERATURE] = true,
82	.direct[PSC_CURRENT_OUT] = true,
83	.m[PSC_VOLTAGE_IN] = 1,
84	.b[PSC_VOLTAGE_IN] = 0,
85	.R[PSC_VOLTAGE_IN] = 3,
86	.m[PSC_VOLTAGE_OUT] = 1,
87	.b[PSC_VOLTAGE_OUT] = 0,
88	.R[PSC_VOLTAGE_OUT] = 3,
89	.m[PSC_TEMPERATURE] = 1,
90	.b[PSC_TEMPERATURE] = 0,
91	.R[PSC_TEMPERATURE] = 3,
92	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT
93		   | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
94		   | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
95		   | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT
96		   | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
97		   | PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12,
98};
99
100static int ds1200_probe(struct i2c_client *client,
101			const struct i2c_device_id *id)
102{
103	return pmbus_do_probe(client, id, &ds1200_info);
104}
105
106static int ds1200_remove(struct i2c_client *client)
107{
108	return pmbus_do_remove(client);
109}
110
111static const struct i2c_device_id ds1200_id[] = {
112	{"ds1200", 0},
113	{}
114};
115
116MODULE_DEVICE_TABLE(i2c, ds1200_id);
117
118/* This is the driver that will be inserted */
119static struct i2c_driver ds1200_driver = {
120	.driver = {
121		   .name = "ds1200",
122		   },
123	.probe = ds1200_probe,
124	.remove = ds1200_remove,
125	.id_table = ds1200_id,
126};
127
128static int __init ds1200_init(void)
129{
130	return i2c_add_driver(&ds1200_driver);
131}
132
133static void __exit ds1200_exit(void)
134{
135	i2c_del_driver(&ds1200_driver);
136}
137
138
139Sysfs entries
140-------------
141
142When probing the chip, the driver identifies which PMBus registers are
143supported, and determines available sensors from this information.
144Attribute files only exist if respective sensors are supported by the chip.
145Labels are provided to inform the user about the sensor associated with
146a given sysfs entry.
147
148The following attributes are supported. Limits are read-write; all other
149attributes are read-only.
150
151inX_input		Measured voltage. From READ_VIN or READ_VOUT register.
152inX_min			Minimum Voltage.
153			From VIN_UV_WARN_LIMIT or VOUT_UV_WARN_LIMIT register.
154inX_max			Maximum voltage.
155			From VIN_OV_WARN_LIMIT or VOUT_OV_WARN_LIMIT register.
156inX_lcrit		Critical minimum Voltage.
157			From VIN_UV_FAULT_LIMIT or VOUT_UV_FAULT_LIMIT register.
158inX_crit		Critical maximum voltage.
159			From VIN_OV_FAULT_LIMIT or VOUT_OV_FAULT_LIMIT register.
160inX_min_alarm		Voltage low alarm. From VOLTAGE_UV_WARNING status.
161inX_max_alarm		Voltage high alarm. From VOLTAGE_OV_WARNING status.
162inX_lcrit_alarm		Voltage critical low alarm.
163			From VOLTAGE_UV_FAULT status.
164inX_crit_alarm		Voltage critical high alarm.
165			From VOLTAGE_OV_FAULT status.
166inX_label		"vin", "vcap", or "voutY"
167
168currX_input		Measured current. From READ_IIN or READ_IOUT register.
169currX_max		Maximum current.
170			From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT register.
171currX_lcrit		Critical minimum output current.
172			From IOUT_UC_FAULT_LIMIT register.
173currX_crit		Critical maximum current.
174			From IIN_OC_FAULT_LIMIT or IOUT_OC_FAULT_LIMIT register.
175currX_alarm		Current high alarm.
176			From IIN_OC_WARNING or IOUT_OC_WARNING status.
177currX_max_alarm		Current high alarm.
178			From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT status.
179currX_lcrit_alarm	Output current critical low alarm.
180			From IOUT_UC_FAULT status.
181currX_crit_alarm	Current critical high alarm.
182			From IIN_OC_FAULT or IOUT_OC_FAULT status.
183currX_label		"iin" or "ioutY"
184
185powerX_input		Measured power. From READ_PIN or READ_POUT register.
186powerX_cap		Output power cap. From POUT_MAX register.
187powerX_max		Power limit. From PIN_OP_WARN_LIMIT or
188			POUT_OP_WARN_LIMIT register.
189powerX_crit		Critical output power limit.
190			From POUT_OP_FAULT_LIMIT register.
191powerX_alarm		Power high alarm.
192			From PIN_OP_WARNING or POUT_OP_WARNING status.
193powerX_crit_alarm	Output power critical high alarm.
194			From POUT_OP_FAULT status.
195powerX_label		"pin" or "poutY"
196
197tempX_input		Measured temperature.
198			From READ_TEMPERATURE_X register.
199tempX_min		Mimimum temperature. From UT_WARN_LIMIT register.
200tempX_max		Maximum temperature. From OT_WARN_LIMIT register.
201tempX_lcrit		Critical low temperature.
202			From UT_FAULT_LIMIT register.
203tempX_crit		Critical high temperature.
204			From OT_FAULT_LIMIT register.
205tempX_min_alarm		Chip temperature low alarm. Set by comparing
206			READ_TEMPERATURE_X with UT_WARN_LIMIT if
207			TEMP_UT_WARNING status is set.
208tempX_max_alarm		Chip temperature high alarm. Set by comparing
209			READ_TEMPERATURE_X with OT_WARN_LIMIT if
210			TEMP_OT_WARNING status is set.
211tempX_lcrit_alarm	Chip temperature critical low alarm. Set by comparing
212			READ_TEMPERATURE_X with UT_FAULT_LIMIT if
213			TEMP_UT_FAULT status is set.
214tempX_crit_alarm	Chip temperature critical high alarm. Set by comparing
215			READ_TEMPERATURE_X with OT_FAULT_LIMIT if
216			TEMP_OT_FAULT status is set.
217