1.. SPDX-License-Identifier: GPL-2.0
2
3Kernel driver tmp513
4====================
5
6Supported chips:
7
8  * Texas Instruments TMP512
9
10    Prefix: 'tmp512'
11
12    Datasheet: http://www.ti.com/lit/ds/symlink/tmp512.pdf
13
14  * Texas Instruments TMP513
15
16    Prefix: 'tmp513'
17
18    Datasheet: http://www.ti.com/lit/ds/symlink/tmp513.pdf
19
20Authors:
21
22	Eric Tremblay <etremblay@distech-controls.com>
23
24Description
25-----------
26
27This driver implements support for Texas Instruments TMP512, and TMP513.
28The TMP512 (dual-channel) and TMP513 (triple-channel) are system monitors
29that include remote sensors, a local temperature sensor, and a high-side current
30shunt monitor. These system monitors have the capability of measuring remote
31temperatures, on-chip temperatures, and system voltage/power/current
32consumption.
33
34The temperatures are measured in degrees Celsius with a range of
35-40 to + 125 degrees with a resolution of 0.0625 degree C.
36
37For hysteresis value, only the first channel is writable. Writing to it
38will affect all other values since each channels are sharing the same
39hysteresis value. The hysteresis is in degrees Celsius with a range of
400 to 127.5 degrees with a resolution of 0.5 degree.
41
42The driver exports the temperature values via the following sysfs files:
43
44**temp[1-4]_input**
45
46**temp[1-4]_crit**
47
48**temp[1-4]_crit_alarm**
49
50**temp[1-4]_crit_hyst**
51
52The driver read the shunt voltage from the chip and convert it to current.
53The readable range depends on the "ti,pga-gain" property (default to 8) and the
54shunt resistor value. The value resolution will be equal to 10uV/Rshunt.
55
56The driver exports the shunt currents values via the following sysFs files:
57
58**curr1_input**
59
60**curr1_lcrit**
61
62**curr1_lcrit_alarm**
63
64**curr1_crit**
65
66**curr1_crit_alarm**
67
68The bus voltage range is read from the chip with a resolution of 4mV. The chip
69can be configurable in two different range (32V or 16V) using the
70ti,bus-range-microvolt property in the devicetree.
71
72The driver exports the bus voltage values via the following sysFs files:
73
74**in0_input**
75
76**in0_lcrit**
77
78**in0_lcrit_alarm**
79
80**in0_crit**
81
82**in0_crit_alarm**
83
84The bus power and bus currents range and resolution depends on the calibration
85register value. Those values are calculate by the hardware using those
86formulas:
87
88Current = (ShuntVoltage * CalibrationRegister) / 4096
89Power   = (Current * BusVoltage) / 5000
90
91The driver exports the bus current and bus power values via the following
92sysFs files:
93
94**curr2_input**
95
96**power1_input**
97
98**power1_crit**
99
100**power1_crit_alarm**
101
102The calibration process follow the procedure of the datasheet (without overflow)
103and depend on the shunt resistor value and the pga_gain value.
104