Kernel driver ltc2945

Supported chips:

Author: Guenter Roeck <linux@roeck-us.net>

Description

The LTC2945 is a rail-to-rail system monitor that measures current, voltage, and power consumption.

Usage Notes

This driver does not probe for LTC2945 devices, since there is no register which can be safely used to identify the chip. You will have to instantiate the devices explicitly.

Example: the following will load the driver for an LTC2945 at address 0x10 on I2C bus #1:

$ modprobe ltc2945
$ echo ltc2945 0x10 > /sys/bus/i2c/devices/i2c-1/new_device

Sysfs entries

Voltage readings provided by this driver are reported as obtained from the ADC registers. If a set of voltage divider resistors is installed, calculate the real voltage by multiplying the reported value with (R1+R2)/R2, where R1 is the value of the divider resistor against the measured voltage and R2 is the value of the divider resistor against Ground.

Current reading provided by this driver is reported as obtained from the ADC Current Sense register. The reported value assumes that a 1 mOhm sense resistor is installed. If a different sense resistor is installed, calculate the real current by dividing the reported value by the sense resistor value in mOhm.

in1_input

VIN voltage (mV). Voltage is measured either at SENSE+ or VDD pin depending on chip configuration.

in1_min

Undervoltage threshold

in1_max

Overvoltage threshold

in1_lowest

Lowest measured voltage

in1_highest

Highest measured voltage

in1_reset_history

Write 1 to reset in1 history

in1_min_alarm

Undervoltage alarm

in1_max_alarm

Overvoltage alarm

in2_input

ADIN voltage (mV)

in2_min

Undervoltage threshold

in2_max

Overvoltage threshold

in2_lowest

Lowest measured voltage

in2_highest

Highest measured voltage

in2_reset_history

Write 1 to reset in2 history

in2_min_alarm

Undervoltage alarm

in2_max_alarm

Overvoltage alarm

curr1_input

SENSE current (mA)

curr1_min

Undercurrent threshold

curr1_max

Overcurrent threshold

curr1_lowest

Lowest measured current

curr1_highest

Highest measured current

curr1_reset_history

Write 1 to reset curr1 history

curr1_min_alarm

Undercurrent alarm

curr1_max_alarm

Overcurrent alarm

power1_input

Power (in uW). Power is calculated based on SENSE+/VDD voltage or ADIN voltage depending on chip configuration.

power1_min

Low lower threshold

power1_max

High power threshold

power1_input_lowest

Historical minimum power use

power1_input_highest

Historical maximum power use

power1_reset_history

Write 1 to reset power1 history

power1_min_alarm

Low power alarm

power1_max_alarm

High power alarm