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Guenter Roeck44f5a402010-06-28 14:29:03 -07001Kernel driver pmbus
2====================
3
4Supported chips:
5 * Ericsson BMR45X series
6 DC/DC Converter
7 Prefixes: 'bmr450', 'bmr451', 'bmr453', 'bmr454'
8 Addresses scanned: -
9 Datasheet:
10 http://archive.ericsson.net/service/internet/picov/get?DocNo=28701-EN/LZT146395
11 * Linear Technology LTC2978
12 Octal PMBus Power Supply Monitor and Controller
13 Prefix: 'ltc2978'
14 Addresses scanned: -
15 Datasheet: http://cds.linear.com/docs/Datasheet/2978fa.pdf
16 * Maxim MAX16064
17 Quad Power-Supply Controller
18 Prefix: 'max16064'
19 Addresses scanned: -
20 Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX16064.pdf
21 * Maxim MAX34440
22 PMBus 6-Channel Power-Supply Manager
23 Prefixes: 'max34440'
24 Addresses scanned: -
25 Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX34440.pdf
26 * Maxim MAX34441
27 PMBus 5-Channel Power-Supply Manager and Intelligent Fan Controller
28 Prefixes: 'max34441'
29 Addresses scanned: -
30 Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX34441.pdf
31 * Maxim MAX8688
32 Digital Power-Supply Controller/Monitor
33 Prefix: 'max8688'
34 Addresses scanned: -
35 Datasheet: http://datasheets.maxim-ic.com/en/ds/MAX8688.pdf
36 * Generic PMBus devices
37 Prefix: 'pmbus'
38 Addresses scanned: -
39 Datasheet: n.a.
40
41Author: Guenter Roeck <guenter.roeck@ericsson.com>
42
43
44Description
45-----------
46
47This driver supports hardware montoring for various PMBus compliant devices.
48It supports voltage, current, power, and temperature sensors as supported
49by the device.
50
51Each monitored channel has its own high and low limits, plus a critical
52limit.
53
54Fan support will be added in a later version of this driver.
55
56
57Usage Notes
58-----------
59
60This driver does not probe for PMBus devices, since there is no register
61which can be safely used to identify the chip (The MFG_ID register is not
62supported by all chips), and since there is no well defined address range for
63PMBus devices. You will have to instantiate the devices explicitly.
64
65Example: the following will load the driver for an LTC2978 at address 0x60
66on I2C bus #1:
67$ modprobe pmbus
68$ echo ltc2978 0x60 > /sys/bus/i2c/devices/i2c-1/new_device
69
70
71Platform data support
72---------------------
73
74Support for additional PMBus chips can be added by defining chip parameters in
75a new chip specific driver file. For example, (untested) code to add support for
76Emerson DS1200 power modules might look as follows.
77
78static struct pmbus_driver_info ds1200_info = {
79 .pages = 1,
80 /* Note: All other sensors are in linear mode */
81 .direct[PSC_VOLTAGE_OUT] = true,
82 .direct[PSC_TEMPERATURE] = true,
83 .direct[PSC_CURRENT_OUT] = true,
84 .m[PSC_VOLTAGE_IN] = 1,
85 .b[PSC_VOLTAGE_IN] = 0,
86 .R[PSC_VOLTAGE_IN] = 3,
87 .m[PSC_VOLTAGE_OUT] = 1,
88 .b[PSC_VOLTAGE_OUT] = 0,
89 .R[PSC_VOLTAGE_OUT] = 3,
90 .m[PSC_TEMPERATURE] = 1,
91 .b[PSC_TEMPERATURE] = 0,
92 .R[PSC_TEMPERATURE] = 3,
93 .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_STATUS_INPUT
94 | PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT
95 | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT
96 | PMBUS_HAVE_PIN | PMBUS_HAVE_POUT
97 | PMBUS_HAVE_TEMP | PMBUS_HAVE_STATUS_TEMP
98 | PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12,
99};
100
101static int ds1200_probe(struct i2c_client *client,
102 const struct i2c_device_id *id)
103{
104 return pmbus_do_probe(client, id, &ds1200_info);
105}
106
107static int ds1200_remove(struct i2c_client *client)
108{
109 return pmbus_do_remove(client);
110}
111
112static const struct i2c_device_id ds1200_id[] = {
113 {"ds1200", 0},
114 {}
115};
116
117MODULE_DEVICE_TABLE(i2c, ds1200_id);
118
119/* This is the driver that will be inserted */
120static struct i2c_driver ds1200_driver = {
121 .driver = {
122 .name = "ds1200",
123 },
124 .probe = ds1200_probe,
125 .remove = ds1200_remove,
126 .id_table = ds1200_id,
127};
128
129static int __init ds1200_init(void)
130{
131 return i2c_add_driver(&ds1200_driver);
132}
133
134static void __exit ds1200_exit(void)
135{
136 i2c_del_driver(&ds1200_driver);
137}
138
139
140Sysfs entries
141-------------
142
143When probing the chip, the driver identifies which PMBus registers are
144supported, and determines available sensors from this information.
145Attribute files only exist if respective sensors are suported by the chip.
146Labels are provided to inform the user about the sensor associated with
147a given sysfs entry.
148
149The following attributes are supported. Limits are read-write; all other
150attributes are read-only.
151
152inX_input Measured voltage. From READ_VIN or READ_VOUT register.
153inX_min Minumum Voltage.
154 From VIN_UV_WARN_LIMIT or VOUT_UV_WARN_LIMIT register.
155inX_max Maximum voltage.
156 From VIN_OV_WARN_LIMIT or VOUT_OV_WARN_LIMIT register.
157inX_lcrit Critical minumum Voltage.
158 From VIN_UV_FAULT_LIMIT or VOUT_UV_FAULT_LIMIT register.
159inX_crit Critical maximum voltage.
160 From VIN_OV_FAULT_LIMIT or VOUT_OV_FAULT_LIMIT register.
161inX_min_alarm Voltage low alarm. From VOLTAGE_UV_WARNING status.
162inX_max_alarm Voltage high alarm. From VOLTAGE_OV_WARNING status.
163inX_lcrit_alarm Voltage critical low alarm.
164 From VOLTAGE_UV_FAULT status.
165inX_crit_alarm Voltage critical high alarm.
166 From VOLTAGE_OV_FAULT status.
167inX_label "vin", "vcap", or "voutY"
168
169currX_input Measured current. From READ_IIN or READ_IOUT register.
170currX_max Maximum current.
171 From IIN_OC_WARN_LIMIT or IOUT_OC_WARN_LIMIT register.
172currX_lcrit Critical minumum output current.
173 From IOUT_UC_FAULT_LIMIT register.
174currX_crit Critical maximum current.
175 From IIN_OC_FAULT_LIMIT or IOUT_OC_FAULT_LIMIT register.
176currX_alarm Current high alarm.
177 From IIN_OC_WARNING or IOUT_OC_WARNING status.
178currX_lcrit_alarm Output current critical low alarm.
179 From IOUT_UC_FAULT status.
180currX_crit_alarm Current critical high alarm.
181 From IIN_OC_FAULT or IOUT_OC_FAULT status.
182currX_label "iin" or "vinY"
183
184powerX_input Measured power. From READ_PIN or READ_POUT register.
185powerX_cap Output power cap. From POUT_MAX register.
186powerX_max Power limit. From PIN_OP_WARN_LIMIT or
187 POUT_OP_WARN_LIMIT register.
188powerX_crit Critical output power limit.
189 From POUT_OP_FAULT_LIMIT register.
190powerX_alarm Power high alarm.
191 From PIN_OP_WARNING or POUT_OP_WARNING status.
192powerX_crit_alarm Output power critical high alarm.
193 From POUT_OP_FAULT status.
194powerX_label "pin" or "poutY"
195
196tempX_input Measured tempererature.
197 From READ_TEMPERATURE_X register.
198tempX_min Mimimum tempererature. From UT_WARN_LIMIT register.
199tempX_max Maximum tempererature. From OT_WARN_LIMIT register.
200tempX_lcrit Critical low tempererature.
201 From UT_FAULT_LIMIT register.
202tempX_crit Critical high tempererature.
203 From OT_FAULT_LIMIT register.
204tempX_min_alarm Chip temperature low alarm. Set by comparing
205 READ_TEMPERATURE_X with UT_WARN_LIMIT if
206 TEMP_UT_WARNING status is set.
207tempX_max_alarm Chip temperature high alarm. Set by comparing
208 READ_TEMPERATURE_X with OT_WARN_LIMIT if
209 TEMP_OT_WARNING status is set.
210tempX_lcrit_alarm Chip temperature critical low alarm. Set by comparing
211 READ_TEMPERATURE_X with UT_FAULT_LIMIT if
212 TEMP_UT_FAULT status is set.
213tempX_crit_alarm Chip temperature critical high alarm. Set by comparing
214 READ_TEMPERATURE_X with OT_FAULT_LIMIT if
215 TEMP_OT_FAULT status is set.