This patch implements the summation feature of INA3221, mainly the
SCC (enabling) and SF (warning flag) bits of MASK_ENABLE register,
INA3221_SHUNT_SUM (summation of shunt voltages) register, and the
INA3221_CRIT_SUM (its critical alert setting) register.
Although the summation feature allows user to select which channels
to be added to the result, as an initial support, this patch simply
selects all channels by default, with one only condition: all shunt
resistor values need to be the same. This is because the summation
of current channels can be only accurately calculated, using shunt
voltage sum register, if all shunt resistors are equivalent.
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Link: https://lore.kernel.org/r/20191016235702.22039-1-nicoleotsuka@gmail.com
[groeck: summation->sum in documentation and label]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
The CONFIG register has two 3-bit fields for conversion time
settings of Bus-voltage and Shunt-voltage, respectively. The
conversion settings, along with averaging mode, allow users
to optimize available timing requirement.
This patch adds an 'update_interval' sysfs node through the
hwmon_chip_info of hwmon core. It reflects a total hardware
conversion time:
samples * channels * (Bus + Shunt conversion times)
Though INA3221 supports different conversion time setups for
Bus and Shunt voltages, this patch only adds the support of
a unified setting for both conversion times, by dividing the
conversion time into two equal values.
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
[groeck: .rst related formatting changes in documentation]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Now that all files were converted to ReST format, rename them
and add an index.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
