mirror of
https://github.com/torvalds/linux.git
synced 2024-11-22 04:02:20 +00:00
9f90fd652b
The ltc2947 is a high precision power and energy monitor with an internal sense resistor supporting up to +/- 30A. Three internal no Latency ADCs ensure accurate measurement of voltage and current, while high-bandwidth analog multiplication of voltage and current provides accurate power measurement in a wide range of applications. Internal or external clocking options enable precise charge and energy measurements. Signed-off-by: Nuno Sá <nuno.sa@analog.com> Link: https://lore.kernel.org/r/20191021154115.319073-1-nuno.sa@analog.com [groeck: Removed unnecessary checks when reading temperature and energy; PAGE{0,1} -> LTC2947_PAGE_{0,1}] Signed-off-by: Guenter Roeck <linux@roeck-us.net>
101 lines
3.5 KiB
ReStructuredText
101 lines
3.5 KiB
ReStructuredText
Kernel drivers ltc2947-i2c and ltc2947-spi
|
|
==========================================
|
|
|
|
Supported chips:
|
|
|
|
* Analog Devices LTC2947
|
|
|
|
Prefix: 'ltc2947'
|
|
|
|
Addresses scanned: -
|
|
|
|
Datasheet:
|
|
|
|
https://www.analog.com/media/en/technical-documentation/data-sheets/LTC2947.pdf
|
|
|
|
Author: Nuno Sá <nuno.sa@analog.com>
|
|
|
|
Description
|
|
___________
|
|
|
|
The LTC2947 is a high precision power and energy monitor that measures current,
|
|
voltage, power, temperature, charge and energy. The device supports both SPI
|
|
and I2C depending on the chip configuration.
|
|
The device also measures accumulated quantities as energy. It has two banks of
|
|
register's to read/set energy related values. These banks can be configured
|
|
independently to have setups like: energy1 accumulates always and enrgy2 only
|
|
accumulates if current is positive (to check battery charging efficiency for
|
|
example). The device also supports a GPIO pin that can be configured as output
|
|
to control a fan as a function of measured temperature. Then, the GPIO becomes
|
|
active as soon as a temperature reading is higher than a defined threshold. The
|
|
temp2 channel is used to control this thresholds and to read the respective
|
|
alarms.
|
|
|
|
Sysfs entries
|
|
_____________
|
|
|
|
The following attributes are supported. Limits are read-write, reset_history
|
|
is write-only and all the other attributes are read-only.
|
|
|
|
======================= ==========================================
|
|
in0_input VP-VM voltage (mV).
|
|
in0_min Undervoltage threshold
|
|
in0_max Overvoltage threshold
|
|
in0_lowest Lowest measured voltage
|
|
in0_highest Highest measured voltage
|
|
in0_reset_history Write 1 to reset in1 history
|
|
in0_min_alarm Undervoltage alarm
|
|
in0_max_alarm Overvoltage alarm
|
|
in0_label Channel label (VP-VM)
|
|
|
|
in1_input DVCC voltage (mV)
|
|
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 in2 history
|
|
in1_min_alarm Undervoltage alarm
|
|
in1_max_alarm Overvoltage alarm
|
|
in1_label Channel label (DVCC)
|
|
|
|
curr1_input IP-IM 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
|
|
curr1_label Channel label (IP-IM)
|
|
|
|
power1_input Power (in uW)
|
|
power1_min Low power 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
|
|
power1_label Channel label (Power)
|
|
|
|
temp1_input Chip Temperature (in milliC)
|
|
temp1_min Low temperature threshold
|
|
temp1_max High temperature threshold
|
|
temp1_input_lowest Historical minimum temperature use
|
|
temp1_input_highest Historical maximum temperature use
|
|
temp1_reset_history Write 1 to reset temp1 history
|
|
temp1_min_alarm Low temperature alarm
|
|
temp1_max_alarm High temperature alarm
|
|
temp1_label Channel label (Ambient)
|
|
|
|
temp2_min Low temperature threshold for fan control
|
|
temp2_max High temperature threshold for fan control
|
|
temp2_min_alarm Low temperature fan control alarm
|
|
temp2_max_alarm High temperature fan control alarm
|
|
temp2_label Channel label (TEMPFAN)
|
|
|
|
energy1_input Measured energy over time (in microJoule)
|
|
|
|
energy2_input Measured energy over time (in microJoule)
|
|
======================= ==========================================
|