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hwmon: (tps23861) set current shunt value

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TPS23861 has a configuration bit for setting of the
current shunt value used on the board.
Its bit 0 of the General Mask 1 register.

According to the datasheet bit values are:
0 for 255 mOhm (Default)
1 for 250 mOhm

So, configure the bit before registering the hwmon
device according to the value passed in the DTS or
default one if none is passed.

This caused potentially reading slightly skewed values
due to max current value being 1.02A when 250mOhm shunt
is used instead of 1.0A when 255mOhm is used.

Fixes: fff7b8ab22 ("hwmon: add Texas Instruments TPS23861 driver")
Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Link: https://lore.kernel.org/r/20210609220728.499879-2-robert.marko@sartura.hr
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
This commit is contained in:
Robert Marko 2021-06-10 00:07:27 +02:00 committed by Guenter Roeck
parent fb8543fb86
commit b325d3526e
1 changed files with 12 additions and 0 deletions
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12
drivers/hwmon/tps23861.c
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@ -99,6 +99,9 @@
#define POWER_ENABLE 0x19
#define TPS23861_NUM_PORTS 4
#define TPS23861_GENERAL_MASK_1 0x17
#define TPS23861_CURRENT_SHUNT_MASK BIT(0)
#define TEMPERATURE_LSB 652 /* 0.652 degrees Celsius */
#define VOLTAGE_LSB 3662 /* 3.662 mV */
#define SHUNT_RESISTOR_DEFAULT 255000 /* 255 mOhm */
@ -561,6 +564,15 @@ static int tps23861_probe(struct i2c_client *client)
else
data->shunt_resistor = SHUNT_RESISTOR_DEFAULT;
if (data->shunt_resistor == SHUNT_RESISTOR_DEFAULT)
regmap_clear_bits(data->regmap,
TPS23861_GENERAL_MASK_1,
TPS23861_CURRENT_SHUNT_MASK);
else
regmap_set_bits(data->regmap,
TPS23861_GENERAL_MASK_1,
TPS23861_CURRENT_SHUNT_MASK);
hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
data, &tps23861_chip_info,
NULL);