From 6700ce035f830149d48c270d84736debfb67179e Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Sat, 11 Jan 2014 10:28:05 -0800 Subject: hwmon: Driver for Linear Technologies LTC2945 LTC2945 is a system monitor that measures current, voltage, and power. Signed-off-by: Guenter Roeck --- Documentation/hwmon/ltc2945 | 84 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 84 insertions(+) create mode 100644 Documentation/hwmon/ltc2945 (limited to 'Documentation/hwmon/ltc2945') diff --git a/Documentation/hwmon/ltc2945 b/Documentation/hwmon/ltc2945 new file mode 100644 index 000000000000..f8d0f7f19adb --- /dev/null +++ b/Documentation/hwmon/ltc2945 @@ -0,0 +1,84 @@ +Kernel driver ltc2945 +===================== + +Supported chips: + * Linear Technology LTC2945 + Prefix: 'ltc2945' + Addresses scanned: - + Datasheet: + http://cds.linear.com/docs/en/datasheet/2945fa.pdf + +Author: Guenter Roeck + + +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 -- cgit v1.2.3-59-g8ed1b