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hwmon: (ina238) Report energy in microjoules

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The hwmon sysfs interface specifies that energy values should be
reported in microjoules. This is also what tools such as lmsensors
expect, reporting wrong values otherwise.

Adjust the driver to scale the output accordingly and adjust ina238
driver documentation.

Fixes: 6daaf15a11 ("hwmon: (ina238) Add support for SQ52206")
Signed-off-by: Jonas Rebmann <jre@pengutronix.de>
Link: https://lore.kernel.org/r/20250715-hwmon-ina238-microjoules-v1-1-9df678568a41@pengutronix.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Jonas Rebmann
2025-07-15 15:02:41 +02:00
committed by Guenter Roeck
parent 495a4f0dce
commit 3e8e93cbb8
2 changed files with 5 additions and 5 deletions
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2
Documentation/hwmon/ina238.rst
View File

@@ -65,7 +65,7 @@ Additional sysfs entries for sq52206
------------------------------------
======================= =======================================================
energy1_input Energy measurement (mJ)
energy1_input Energy measurement (uJ)
power1_input_highest Peak Power (uW)
======================= =======================================================

8
drivers/hwmon/ina238.c
View File

@@ -97,7 +97,7 @@
* Power (mW) = 0.2 * register value * 20000 / rshunt / 4 * gain
* (Specific for SQ52206)
* Power (mW) = 0.24 * register value * 20000 / rshunt / 4 * gain
* Energy (mJ) = 16 * 0.24 * register value * 20000 / rshunt / 4 * gain
* Energy (uJ) = 16 * 0.24 * register value * 20000 / rshunt / 4 * gain * 1000
*/
#define INA238_CALIBRATION_VALUE 16384
#define INA238_FIXED_SHUNT 20000
@@ -500,9 +500,9 @@ static ssize_t energy1_input_show(struct device *dev,
if (ret)
return ret;
/* result in mJ */
energy = div_u64(regval * INA238_FIXED_SHUNT * data->gain * 16 *
data->config->power_calculate_factor, 4 * 100 * data->rshunt);
/* result in uJ */
energy = div_u64(regval * INA238_FIXED_SHUNT * data->gain * 16 * 10 *
data->config->power_calculate_factor, 4 * data->rshunt);
return sysfs_emit(buf, "%llu\n", energy);
}