1 Kernel driver ltc2945 1 Kernel driver ltc2945
2 ===================== 2 =====================
3 3
4 Supported chips: 4 Supported chips:
5 5
6 * Linear Technology LTC2945 6 * Linear Technology LTC2945
7 7
8 Prefix: 'ltc2945' 8 Prefix: 'ltc2945'
9 9
10 Addresses scanned: - 10 Addresses scanned: -
11 11
12 Datasheet: 12 Datasheet:
13 13
14 https://www.analog.com/media/en/techni 14 https://www.analog.com/media/en/technical-documentation/data-sheets/2945fb.pdf
15 15
16 Author: Guenter Roeck <linux@roeck-us.net> 16 Author: Guenter Roeck <linux@roeck-us.net>
17 17
18 18
19 Description 19 Description
20 ----------- 20 -----------
21 21
22 The LTC2945 is a rail-to-rail system monitor 22 The LTC2945 is a rail-to-rail system monitor that measures current, voltage,
23 and power consumption. 23 and power consumption.
24 24
25 25
26 Usage Notes 26 Usage Notes
27 ----------- 27 -----------
28 28
29 This driver does not probe for LTC2945 devices 29 This driver does not probe for LTC2945 devices, since there is no register
30 which can be safely used to identify the chip. 30 which can be safely used to identify the chip. You will have to instantiate
31 the devices explicitly. 31 the devices explicitly.
32 32
33 Example: the following will load the driver fo 33 Example: the following will load the driver for an LTC2945 at address 0x10
34 on I2C bus #1:: 34 on I2C bus #1::
35 35
36 $ modprobe ltc2945 36 $ modprobe ltc2945
37 $ echo ltc2945 0x10 > /sys/bus/i2c/dev 37 $ echo ltc2945 0x10 > /sys/bus/i2c/devices/i2c-1/new_device
38 38
39 39
40 Sysfs entries 40 Sysfs entries
41 ------------- 41 -------------
42 42
43 Voltage readings provided by this driver are r 43 Voltage readings provided by this driver are reported as obtained from the ADC
44 registers. If a set of voltage divider resisto 44 registers. If a set of voltage divider resistors is installed, calculate the
45 real voltage by multiplying the reported value 45 real voltage by multiplying the reported value with (R1+R2)/R2, where R1 is the
46 value of the divider resistor against the meas 46 value of the divider resistor against the measured voltage and R2 is the value
47 of the divider resistor against Ground. 47 of the divider resistor against Ground.
48 48
49 Current reading provided by this driver is rep 49 Current reading provided by this driver is reported as obtained from the ADC
50 Current Sense register. The reported value ass 50 Current Sense register. The reported value assumes that a 1 mOhm sense resistor
51 is installed. If a different sense resistor is 51 is installed. If a different sense resistor is installed, calculate the real
52 current by dividing the reported value by the 52 current by dividing the reported value by the sense resistor value in mOhm.
53 53
54 ======================= ====================== 54 ======================= ========================================================
55 in1_input VIN voltage (mV). Volt 55 in1_input VIN voltage (mV). Voltage is measured either at
56 SENSE+ or VDD pin depe 56 SENSE+ or VDD pin depending on chip configuration.
57 in1_min Undervoltage threshold 57 in1_min Undervoltage threshold
58 in1_max Overvoltage threshold 58 in1_max Overvoltage threshold
59 in1_lowest Lowest measured voltag 59 in1_lowest Lowest measured voltage
60 in1_highest Highest measured volta 60 in1_highest Highest measured voltage
61 in1_reset_history Write 1 to reset in1 h 61 in1_reset_history Write 1 to reset in1 history
62 in1_min_alarm Undervoltage alarm 62 in1_min_alarm Undervoltage alarm
63 in1_max_alarm Overvoltage alarm 63 in1_max_alarm Overvoltage alarm
64 64
65 in2_input ADIN voltage (mV) 65 in2_input ADIN voltage (mV)
66 in2_min Undervoltage threshold 66 in2_min Undervoltage threshold
67 in2_max Overvoltage threshold 67 in2_max Overvoltage threshold
68 in2_lowest Lowest measured voltag 68 in2_lowest Lowest measured voltage
69 in2_highest Highest measured volta 69 in2_highest Highest measured voltage
70 in2_reset_history Write 1 to reset in2 h 70 in2_reset_history Write 1 to reset in2 history
71 in2_min_alarm Undervoltage alarm 71 in2_min_alarm Undervoltage alarm
72 in2_max_alarm Overvoltage alarm 72 in2_max_alarm Overvoltage alarm
73 73
74 curr1_input SENSE current (mA) 74 curr1_input SENSE current (mA)
75 curr1_min Undercurrent threshold 75 curr1_min Undercurrent threshold
76 curr1_max Overcurrent threshold 76 curr1_max Overcurrent threshold
77 curr1_lowest Lowest measured curren 77 curr1_lowest Lowest measured current
78 curr1_highest Highest measured curre 78 curr1_highest Highest measured current
79 curr1_reset_history Write 1 to reset curr1 79 curr1_reset_history Write 1 to reset curr1 history
80 curr1_min_alarm Undercurrent alarm 80 curr1_min_alarm Undercurrent alarm
81 curr1_max_alarm Overcurrent alarm 81 curr1_max_alarm Overcurrent alarm
82 82
83 power1_input Power (in uW). Power i 83 power1_input Power (in uW). Power is calculated based on SENSE+/VDD
84 voltage or ADIN voltag 84 voltage or ADIN voltage depending on chip configuration.
85 power1_min Low lower threshold 85 power1_min Low lower threshold
86 power1_max High power threshold 86 power1_max High power threshold
87 power1_input_lowest Historical minimum pow 87 power1_input_lowest Historical minimum power use
88 power1_input_highest Historical maximum pow 88 power1_input_highest Historical maximum power use
89 power1_reset_history Write 1 to reset power 89 power1_reset_history Write 1 to reset power1 history
90 power1_min_alarm Low power alarm 90 power1_min_alarm Low power alarm
91 power1_max_alarm High power alarm 91 power1_max_alarm High power alarm
92 ======================= ====================== 92 ======================= ========================================================
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