From: Evgeny Boger boger@wirenboard.com
commit 92beafb76a31bdc02649eb44e93a8e4f4cfcdbe8 upstream.
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.
Fixes: 0e34d5de961d ("iio: adc: add support for X-Powers AXP20X and AXP22X PMICs ADCs") Signed-off-by: Evgeny Boger boger@wirenboard.com Acked-by: Chen-Yu Tsai wens@csie.org Link: https://lore.kernel.org/r/20211116213746.264378-1-boger@wirenboard.com Cc: Stable@vger.kernel.org Signed-off-by: Jonathan Cameron Jonathan.Cameron@huawei.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/iio/adc/axp20x_adc.c | 18 +++--------------- 1 file changed, 3 insertions(+), 15 deletions(-)
--- a/drivers/iio/adc/axp20x_adc.c +++ b/drivers/iio/adc/axp20x_adc.c @@ -254,19 +254,8 @@ static int axp22x_adc_raw(struct iio_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;
@@ -389,9 +378,8 @@ static int axp22x_adc_scale(struct iio_c 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;