2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-26 06:04:14 +08:00
linux-next/Documentation/hwmon/ina3221.rst
Nicolin Chen 023912dbb8 hwmon: (ina3221) Add voltage conversion time settings
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>
2019-04-18 06:44:11 -07:00

63 lines
2.3 KiB
ReStructuredText

Kernel driver ina3221
=====================
Supported chips:
* Texas Instruments INA3221
Prefix: 'ina3221'
Addresses: I2C 0x40 - 0x43
Datasheet: Publicly available at the Texas Instruments website
http://www.ti.com/
Author: Andrew F. Davis <afd@ti.com>
Description
-----------
The Texas Instruments INA3221 monitors voltage, current, and power on the high
side of up to three D.C. power supplies. The INA3221 monitors both shunt drop
and supply voltage, with programmable conversion times and averaging, current
and power are calculated host-side from these.
Sysfs entries
-------------
======================= =======================================================
in[123]_label Voltage channel labels
in[123]_enable Voltage channel enable controls
in[123]_input Bus voltage(mV) channels
curr[123]_input Current(mA) measurement channels
shunt[123]_resistor Shunt resistance(uOhm) channels
curr[123]_crit Critical alert current(mA) setting, activates the
corresponding alarm when the respective current
is above this value
curr[123]_crit_alarm Critical alert current limit exceeded
curr[123]_max Warning alert current(mA) setting, activates the
corresponding alarm when the respective current
average is above this value.
curr[123]_max_alarm Warning alert current limit exceeded
in[456]_input Shunt voltage(uV) for channels 1, 2, and 3 respectively
samples Number of samples using in the averaging mode.
Supports the list of number of samples:
1, 4, 16, 64, 128, 256, 512, 1024
update_interval Data conversion time in millisecond, following:
update_interval = C x S x (BC + SC)
* C: number of enabled channels
* S: number of samples
* BC: bus-voltage conversion time in millisecond
* SC: shunt-voltage conversion time in millisecond
Affects both Bus- and Shunt-voltage conversion time.
Note that setting update_interval to 0ms sets both BC
and SC to 140 us (minimum conversion time).
======================= =======================================================