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review.shift-gmbh.com / SHIFTPHONES / mainline / linux / 8c4a93a1270ddffc7660ae43fa8030ecfe9c06d9 / . / Documentation / hwmon / ltc2990.rst
blob: e0a369e679d3172844057ba18c3eb9c59f8aa87e [file] [log] [blame]
Mike Looijmansdf922702016-01-15 10:54:59 +0100[diff] [blame]1Kernel driver ltc2990
2=====================
3
Mauro Carvalho Chehabb04f2f72019-04-17 06:46:28 -0300[diff] [blame]4
Mike Looijmansdf922702016-01-15 10:54:59 +0100[diff] [blame]5Supported chips:
Mauro Carvalho Chehabb04f2f72019-04-17 06:46:28 -0300[diff] [blame]6
Mike Looijmansdf922702016-01-15 10:54:59 +0100[diff] [blame]7 * Linear Technology LTC2990
Mauro Carvalho Chehabb04f2f72019-04-17 06:46:28 -0300[diff] [blame]8
Mike Looijmansdf922702016-01-15 10:54:59 +0100[diff] [blame]9 Prefix: 'ltc2990'
Mauro Carvalho Chehabb04f2f72019-04-17 06:46:28 -0300[diff] [blame]10
Mike Looijmansdf922702016-01-15 10:54:59 +0100[diff] [blame]11 Addresses scanned: -
Mauro Carvalho Chehabb04f2f72019-04-17 06:46:28 -0300[diff] [blame]12
Mike Looijmansdf922702016-01-15 10:54:59 +0100[diff] [blame]13 Datasheet: http://www.linear.com/product/ltc2990
14
Mauro Carvalho Chehabb04f2f72019-04-17 06:46:28 -0300[diff] [blame]15
16
17Author:
18
19 - Mike Looijmans <mike.looijmans@topic.nl>
20 - Tom Levens <tom.levens@cern.ch>
Mike Looijmansdf922702016-01-15 10:54:59 +0100[diff] [blame]21
22
23Description
24-----------
25
26LTC2990 is a Quad I2C Voltage, Current and Temperature Monitor.
27The chip's inputs can measure 4 voltages, or two inputs together (1+2 and 3+4)
28can be combined to measure a differential voltage, which is typically used to
Tom Levens5d9ca432017-07-03 06:29:00 +0200[diff] [blame]29measure current through a series resistor, or a temperature with an external
30diode.
Mike Looijmansdf922702016-01-15 10:54:59 +0100[diff] [blame]31
32
33Usage Notes
34-----------
35
36This driver does not probe for PMBus devices. You will have to instantiate
37devices explicitly.
38
39
40Sysfs attributes
41----------------
42
Mauro Carvalho Chehabb04f2f72019-04-17 06:46:28 -0300[diff] [blame]43============= ==================================================
Tom Levens5d9ca432017-07-03 06:29:00 +0200[diff] [blame]44in0_input Voltage at Vcc pin in millivolt (range 2.5V to 5V)
Mauro Carvalho Chehabb04f2f72019-04-17 06:46:28 -0300[diff] [blame]45temp1_input Internal chip temperature in millidegrees Celsius
46============= ==================================================
Tom Levens5d9ca432017-07-03 06:29:00 +0200[diff] [blame]47
48A subset of the following attributes are visible, depending on the measurement
49mode of the chip.
50
Mauro Carvalho Chehabb04f2f72019-04-17 06:46:28 -0300[diff] [blame]51============= ==========================================================
Tom Levens5d9ca432017-07-03 06:29:00 +0200[diff] [blame]52in[1-4]_input Voltage at V[1-4] pin in millivolt
Mauro Carvalho Chehabb04f2f72019-04-17 06:46:28 -0300[diff] [blame]53temp2_input External temperature sensor TR1 in millidegrees Celsius
54temp3_input External temperature sensor TR2 in millidegrees Celsius
Tom Levens5d9ca432017-07-03 06:29:00 +0200[diff] [blame]55curr1_input Current in mA across V1-V2 assuming a 1mOhm sense resistor
56curr2_input Current in mA across V3-V4 assuming a 1mOhm sense resistor
Mauro Carvalho Chehabb04f2f72019-04-17 06:46:28 -0300[diff] [blame]57============= ==========================================================
Tom Levens5d9ca432017-07-03 06:29:00 +0200[diff] [blame]58
Mike Looijmansdf922702016-01-15 10:54:59 +0100[diff] [blame]59The "curr*_input" measurements actually report the voltage drop across the
60input pins in microvolts. This is equivalent to the current through a 1mOhm
61sense resistor. Divide the reported value by the actual sense resistor value
62in mOhm to get the actual value.