| Message ID | 20210306235238.30379-1-boger@wirenboard.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | iio: adc: axp20x_adc: fix charging current reporting on AXP22x | expand |
On Sun, 7 Mar 2021 02:52:38 +0300 Evgeny Boger <boger@wirenboard.com> wrote: > 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 additional bit in register width. > > Tested on custom A40i+AXP221s board with external ammeter as > a reference. > > Signed-off-by: Evgeny Boger <boger@wirenboard.com> +CC Quentin's bootlin address. One comment inline, Jonathan > --- > drivers/iio/adc/axp20x_adc.c | 14 ++------------ > 1 file changed, 2 insertions(+), 12 deletions(-) > > diff --git a/drivers/iio/adc/axp20x_adc.c b/drivers/iio/adc/axp20x_adc.c > index 3e0c0233b431..8db6699c20c3 100644 > --- a/drivers/iio/adc/axp20x_adc.c > +++ b/drivers/iio/adc/axp20x_adc.c > @@ -253,17 +253,7 @@ static int axp22x_adc_raw(struct iio_dev *indio_dev, > 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; > > @@ -387,7 +377,7 @@ static int axp22x_adc_scale(struct iio_chan_spec const *chan, int *val, > > case IIO_CURRENT: > *val = 0; > - *val2 = 500000; > + *val2 = 1000000; > return IIO_VAL_INT_PLUS_MICRO; *val = 1; return IIO_VAL_INT; Should work if the scale factor is 1. Note that we could just have reported the channel as _processed in the first place, but given we didn't better to keep the ABI the same and just have a noop scale factor. > > case IIO_TEMP:
diff --git a/drivers/iio/adc/axp20x_adc.c b/drivers/iio/adc/axp20x_adc.c index 3e0c0233b431..8db6699c20c3 100644 --- a/drivers/iio/adc/axp20x_adc.c +++ b/drivers/iio/adc/axp20x_adc.c @@ -253,17 +253,7 @@ static int axp22x_adc_raw(struct iio_dev *indio_dev, 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; @@ -387,7 +377,7 @@ static int axp22x_adc_scale(struct iio_chan_spec const *chan, int *val, case IIO_CURRENT: *val = 0; - *val2 = 500000; + *val2 = 1000000; return IIO_VAL_INT_PLUS_MICRO; case IIO_TEMP:
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 additional bit in register width. Tested on custom A40i+AXP221s board with external ammeter as a reference. Signed-off-by: Evgeny Boger <boger@wirenboard.com> --- drivers/iio/adc/axp20x_adc.c | 14 ++------------ 1 file changed, 2 insertions(+), 12 deletions(-)