1 Kernel driver ina3221 1 Kernel driver ina3221
2 ===================== 2 =====================
3 3
4 Supported chips: 4 Supported chips:
5 5
6 * Texas Instruments INA3221 6 * Texas Instruments INA3221
7 7
8 Prefix: 'ina3221' 8 Prefix: 'ina3221'
9 9
10 Addresses: I2C 0x40 - 0x43 10 Addresses: I2C 0x40 - 0x43
11 11
12 Datasheet: Publicly available at the Texas 12 Datasheet: Publicly available at the Texas Instruments website
13 13
14 https://www.ti.com/ 14 https://www.ti.com/
15 15
16 Author: Andrew F. Davis <afd@ti.com> 16 Author: Andrew F. Davis <afd@ti.com>
17 17
18 Description 18 Description
19 ----------- 19 -----------
20 20
21 The Texas Instruments INA3221 monitors voltage 21 The Texas Instruments INA3221 monitors voltage, current, and power on the high
22 side of up to three D.C. power supplies. The I 22 side of up to three D.C. power supplies. The INA3221 monitors both shunt drop
23 and supply voltage, with programmable conversi 23 and supply voltage, with programmable conversion times and averaging, current
24 and power are calculated host-side from these. 24 and power are calculated host-side from these.
25 25
26 Sysfs entries 26 Sysfs entries
27 ------------- 27 -------------
28 28
29 ======================= ====================== 29 ======================= =======================================================
30 in[123]_label Voltage channel labels 30 in[123]_label Voltage channel labels
31 in[123]_enable Voltage channel enable 31 in[123]_enable Voltage channel enable controls
32 in[123]_input Bus voltage(mV) channe 32 in[123]_input Bus voltage(mV) channels
33 curr[123]_input Current(mA) measuremen 33 curr[123]_input Current(mA) measurement channels
34 shunt[123]_resistor Shunt resistance(uOhm) 34 shunt[123]_resistor Shunt resistance(uOhm) channels
35 curr[123]_crit Critical alert current 35 curr[123]_crit Critical alert current(mA) setting, activates the
36 corresponding alarm wh 36 corresponding alarm when the respective current
37 is above this value 37 is above this value
38 curr[123]_crit_alarm Critical alert current 38 curr[123]_crit_alarm Critical alert current limit exceeded
39 curr[123]_max Warning alert current( 39 curr[123]_max Warning alert current(mA) setting, activates the
40 corresponding alarm wh 40 corresponding alarm when the respective current
41 average is above this 41 average is above this value.
42 curr[123]_max_alarm Warning alert current 42 curr[123]_max_alarm Warning alert current limit exceeded
43 in[456]_input Shunt voltage(uV) for 43 in[456]_input Shunt voltage(uV) for channels 1, 2, and 3 respectively
44 in7_input Sum of shunt voltage(u 44 in7_input Sum of shunt voltage(uV) channels
45 in7_label Channel label for sum 45 in7_label Channel label for sum of shunt voltage
46 curr4_input Sum of current(mA) mea 46 curr4_input Sum of current(mA) measurement channels,
47 (only available when a 47 (only available when all channels use the same resistor
48 value for their shunt 48 value for their shunt resistors)
49 curr4_crit Critical alert current 49 curr4_crit Critical alert current(mA) setting for sum of current
50 measurements, activate 50 measurements, activates the corresponding alarm
51 when the respective cu 51 when the respective current is above this value
52 (only effective when a 52 (only effective when all channels use the same resistor
53 value for their shunt 53 value for their shunt resistors)
54 curr4_crit_alarm Critical alert current 54 curr4_crit_alarm Critical alert current limit exceeded for sum of
55 current measurements. 55 current measurements.
56 samples Number of samples usin 56 samples Number of samples using in the averaging mode.
57 57
58 Supports the list of n 58 Supports the list of number of samples:
59 59
60 1, 4, 16, 64, 128, 2 60 1, 4, 16, 64, 128, 256, 512, 1024
61 61
62 update_interval Data conversion time i 62 update_interval Data conversion time in millisecond, following:
63 63
64 update_interval = C 64 update_interval = C x S x (BC + SC)
65 65
66 * C: number of enab 66 * C: number of enabled channels
67 * S: number of samp 67 * S: number of samples
68 * BC: bus-voltage co 68 * BC: bus-voltage conversion time in millisecond
69 * SC: shunt-voltage 69 * SC: shunt-voltage conversion time in millisecond
70 70
71 Affects both Bus- and 71 Affects both Bus- and Shunt-voltage conversion time.
72 Note that setting upda 72 Note that setting update_interval to 0ms sets both BC
73 and SC to 140 us (mini 73 and SC to 140 us (minimum conversion time).
74 ======================= ====================== 74 ======================= =======================================================
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