ltc2947.rst (3565B)
1Kernel drivers ltc2947-i2c and ltc2947-spi 2========================================== 3 4Supported chips: 5 6 * Analog Devices LTC2947 7 8 Prefix: 'ltc2947' 9 10 Addresses scanned: - 11 12 Datasheet: 13 14 https://www.analog.com/media/en/technical-documentation/data-sheets/LTC2947.pdf 15 16Author: Nuno Sá <nuno.sa@analog.com> 17 18Description 19___________ 20 21The LTC2947 is a high precision power and energy monitor that measures current, 22voltage, power, temperature, charge and energy. The device supports both SPI 23and I2C depending on the chip configuration. 24The device also measures accumulated quantities as energy. It has two banks of 25register's to read/set energy related values. These banks can be configured 26independently to have setups like: energy1 accumulates always and enrgy2 only 27accumulates if current is positive (to check battery charging efficiency for 28example). The device also supports a GPIO pin that can be configured as output 29to control a fan as a function of measured temperature. Then, the GPIO becomes 30active as soon as a temperature reading is higher than a defined threshold. The 31temp2 channel is used to control this thresholds and to read the respective 32alarms. 33 34Sysfs entries 35_____________ 36 37The following attributes are supported. Limits are read-write, reset_history 38is write-only and all the other attributes are read-only. 39 40======================= ========================================== 41in0_input VP-VM voltage (mV). 42in0_min Undervoltage threshold 43in0_max Overvoltage threshold 44in0_lowest Lowest measured voltage 45in0_highest Highest measured voltage 46in0_reset_history Write 1 to reset in1 history 47in0_min_alarm Undervoltage alarm 48in0_max_alarm Overvoltage alarm 49in0_label Channel label (VP-VM) 50 51in1_input DVCC voltage (mV) 52in1_min Undervoltage threshold 53in1_max Overvoltage threshold 54in1_lowest Lowest measured voltage 55in1_highest Highest measured voltage 56in1_reset_history Write 1 to reset in2 history 57in1_min_alarm Undervoltage alarm 58in1_max_alarm Overvoltage alarm 59in1_label Channel label (DVCC) 60 61curr1_input IP-IM Sense current (mA) 62curr1_min Undercurrent threshold 63curr1_max Overcurrent threshold 64curr1_lowest Lowest measured current 65curr1_highest Highest measured current 66curr1_reset_history Write 1 to reset curr1 history 67curr1_min_alarm Undercurrent alarm 68curr1_max_alarm Overcurrent alarm 69curr1_label Channel label (IP-IM) 70 71power1_input Power (in uW) 72power1_min Low power threshold 73power1_max High power threshold 74power1_input_lowest Historical minimum power use 75power1_input_highest Historical maximum power use 76power1_reset_history Write 1 to reset power1 history 77power1_min_alarm Low power alarm 78power1_max_alarm High power alarm 79power1_label Channel label (Power) 80 81temp1_input Chip Temperature (in milliC) 82temp1_min Low temperature threshold 83temp1_max High temperature threshold 84temp1_input_lowest Historical minimum temperature use 85temp1_input_highest Historical maximum temperature use 86temp1_reset_history Write 1 to reset temp1 history 87temp1_min_alarm Low temperature alarm 88temp1_max_alarm High temperature alarm 89temp1_label Channel label (Ambient) 90 91temp2_min Low temperature threshold for fan control 92temp2_max High temperature threshold for fan control 93temp2_min_alarm Low temperature fan control alarm 94temp2_max_alarm High temperature fan control alarm 95temp2_label Channel label (TEMPFAN) 96 97energy1_input Measured energy over time (in microJoule) 98 99energy2_input Measured energy over time (in microJoule) 100======================= ==========================================