Both the charging and discharging currents on AXP22x are stored as
12-bit integers, in accordance with the datasheet.
It's also confirmed by vendor BSP (axp20x_adc.c:axp22_icharge_to_mA).
The scale factor of 0.5 is never mentioned in datasheet, nor in the
vendor source code. I think it was here to compensate for
erroneous addition bit in register width.
Tested on custom A40i+AXP221s board with external ammeter as
a reference.
Signed-off-by: Evgeny Boger <boger@xxxxxxxxxxxxxx>
---
Notes:
Changes from v1:
- return scale factor of 1 as IIO_VAL_INT, not IIO_VAL_INT_PLUS_MICRO
- get rid of unused variable
drivers/iio/adc/axp20x_adc.c | 18 +++---------------
1 file changed, 3 insertions(+), 15 deletions(-)
diff --git a/drivers/iio/adc/axp20x_adc.c b/drivers/iio/adc/axp20x_adc.c
index 3e0c0233b431..df99f1365c39 100644
--- a/drivers/iio/adc/axp20x_adc.c
+++ b/drivers/iio/adc/axp20x_adc.c
@@ -251,19 +251,8 @@ static int axp22x_adc_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int *val)
{
struct axp20x_adc_iio *info = iio_priv(indio_dev);
- int size;
- /*
- * N.B.: Unlike the Chinese datasheets tell, the charging current is
- * stored on 12 bits, not 13 bits. Only discharging current is on 13
- * bits.
- */
- if (chan->type == IIO_CURRENT && chan->channel == AXP22X_BATT_DISCHRG_I)
- size = 13;
- else
- size = 12;
-
- *val = axp20x_read_variable_width(info->regmap, chan->address, size);
+ *val = axp20x_read_variable_width(info->regmap, chan->address, 12);
if (*val < 0)
return *val;
@@ -386,9 +375,8 @@ static int axp22x_adc_scale(struct iio_chan_spec const *chan, int *val,
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CURRENT:
- *val = 0;
- *val2 = 500000;
- return IIO_VAL_INT_PLUS_MICRO;
+ *val = 1;
+ return IIO_VAL_INT;
case IIO_TEMP:
*val = 100;
--
2.25.1
