1 Kernel drivers ltc2947-i2c and ltc2947-spi 1 Kernel drivers ltc2947-i2c and ltc2947-spi
2 ========================================== 2 ==========================================
3 3
4 Supported chips: 4 Supported chips:
5 5
6 * Analog Devices LTC2947 6 * Analog Devices LTC2947
7 7
8 Prefix: 'ltc2947' 8 Prefix: 'ltc2947'
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/LTC2947.pdf
15 15
16 Author: Nuno Sá <nuno.sa@analog.com> 16 Author: Nuno Sá <nuno.sa@analog.com>
17 17
18 Description 18 Description
19 ___________ 19 ___________
20 20
21 The LTC2947 is a high precision power and ener 21 The LTC2947 is a high precision power and energy monitor that measures current,
22 voltage, power, temperature, charge and energy 22 voltage, power, temperature, charge and energy. The device supports both SPI
23 and I2C depending on the chip configuration. 23 and I2C depending on the chip configuration.
24 The device also measures accumulated quantitie 24 The device also measures accumulated quantities as energy. It has two banks of
25 register's to read/set energy related values. 25 register's to read/set energy related values. These banks can be configured
26 independently to have setups like: energy1 acc 26 independently to have setups like: energy1 accumulates always and enrgy2 only
27 accumulates if current is positive (to check b 27 accumulates if current is positive (to check battery charging efficiency for
28 example). The device also supports a GPIO pin 28 example). The device also supports a GPIO pin that can be configured as output
29 to control a fan as a function of measured tem 29 to control a fan as a function of measured temperature. Then, the GPIO becomes
30 active as soon as a temperature reading is hig 30 active as soon as a temperature reading is higher than a defined threshold. The
31 temp2 channel is used to control this threshol 31 temp2 channel is used to control this thresholds and to read the respective
32 alarms. 32 alarms.
33 33
34 Sysfs entries 34 Sysfs entries
35 _____________ 35 _____________
36 36
37 The following attributes are supported. Limits 37 The following attributes are supported. Limits are read-write, reset_history
38 is write-only and all the other attributes are 38 is write-only and all the other attributes are read-only.
39 39
40 ======================= ====================== 40 ======================= ==========================================
41 in0_input VP-VM voltage (mV). 41 in0_input VP-VM voltage (mV).
42 in0_min Undervoltage threshold 42 in0_min Undervoltage threshold
43 in0_max Overvoltage threshold 43 in0_max Overvoltage threshold
44 in0_lowest Lowest measured voltag 44 in0_lowest Lowest measured voltage
45 in0_highest Highest measured volta 45 in0_highest Highest measured voltage
46 in0_reset_history Write 1 to reset in1 h 46 in0_reset_history Write 1 to reset in1 history
47 in0_min_alarm Undervoltage alarm 47 in0_min_alarm Undervoltage alarm
48 in0_max_alarm Overvoltage alarm 48 in0_max_alarm Overvoltage alarm
49 in0_label Channel label (VP-VM) 49 in0_label Channel label (VP-VM)
50 50
51 in1_input DVCC voltage (mV) 51 in1_input DVCC voltage (mV)
52 in1_min Undervoltage threshold 52 in1_min Undervoltage threshold
53 in1_max Overvoltage threshold 53 in1_max Overvoltage threshold
54 in1_lowest Lowest measured voltag 54 in1_lowest Lowest measured voltage
55 in1_highest Highest measured volta 55 in1_highest Highest measured voltage
56 in1_reset_history Write 1 to reset in2 h 56 in1_reset_history Write 1 to reset in2 history
57 in1_min_alarm Undervoltage alarm 57 in1_min_alarm Undervoltage alarm
58 in1_max_alarm Overvoltage alarm 58 in1_max_alarm Overvoltage alarm
59 in1_label Channel label (DVCC) 59 in1_label Channel label (DVCC)
60 60
61 curr1_input IP-IM Sense current (m 61 curr1_input IP-IM Sense current (mA)
62 curr1_min Undercurrent threshold 62 curr1_min Undercurrent threshold
63 curr1_max Overcurrent threshold 63 curr1_max Overcurrent threshold
64 curr1_lowest Lowest measured curren 64 curr1_lowest Lowest measured current
65 curr1_highest Highest measured curre 65 curr1_highest Highest measured current
66 curr1_reset_history Write 1 to reset curr1 66 curr1_reset_history Write 1 to reset curr1 history
67 curr1_min_alarm Undercurrent alarm 67 curr1_min_alarm Undercurrent alarm
68 curr1_max_alarm Overcurrent alarm 68 curr1_max_alarm Overcurrent alarm
69 curr1_label Channel label (IP-IM) 69 curr1_label Channel label (IP-IM)
70 70
71 power1_input Power (in uW) 71 power1_input Power (in uW)
72 power1_min Low power threshold 72 power1_min Low power threshold
73 power1_max High power threshold 73 power1_max High power threshold
74 power1_input_lowest Historical minimum pow 74 power1_input_lowest Historical minimum power use
75 power1_input_highest Historical maximum pow 75 power1_input_highest Historical maximum power use
76 power1_reset_history Write 1 to reset power 76 power1_reset_history Write 1 to reset power1 history
77 power1_min_alarm Low power alarm 77 power1_min_alarm Low power alarm
78 power1_max_alarm High power alarm 78 power1_max_alarm High power alarm
79 power1_label Channel label (Power) 79 power1_label Channel label (Power)
80 80
81 temp1_input Chip Temperature (in m 81 temp1_input Chip Temperature (in milliC)
82 temp1_min Low temperature thresh 82 temp1_min Low temperature threshold
83 temp1_max High temperature thres 83 temp1_max High temperature threshold
84 temp1_input_lowest Historical minimum tem 84 temp1_input_lowest Historical minimum temperature use
85 temp1_input_highest Historical maximum tem 85 temp1_input_highest Historical maximum temperature use
86 temp1_reset_history Write 1 to reset temp1 86 temp1_reset_history Write 1 to reset temp1 history
87 temp1_min_alarm Low temperature alarm 87 temp1_min_alarm Low temperature alarm
88 temp1_max_alarm High temperature alarm 88 temp1_max_alarm High temperature alarm
89 temp1_label Channel label (Ambient 89 temp1_label Channel label (Ambient)
90 90
91 temp2_min Low temperature thresh 91 temp2_min Low temperature threshold for fan control
92 temp2_max High temperature thres 92 temp2_max High temperature threshold for fan control
93 temp2_min_alarm Low temperature fan co 93 temp2_min_alarm Low temperature fan control alarm
94 temp2_max_alarm High temperature fan c 94 temp2_max_alarm High temperature fan control alarm
95 temp2_label Channel label (TEMPFAN 95 temp2_label Channel label (TEMPFAN)
96 96
97 energy1_input Measured energy over t 97 energy1_input Measured energy over time (in microJoule)
98 98
99 energy2_input Measured energy over t 99 energy2_input Measured energy over time (in microJoule)
100 ======================= ====================== 100 ======================= ==========================================
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