patch "iio: adc: axp20x_adc: fix charging current reporting on AXP22x" added to char-misc-linus

This is a note to let you know that I've just added the patch titled

    iio: adc: axp20x_adc: fix charging current reporting on AXP22x

to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-linus branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.

If you have any questions about this process, please let me know.

From 92beafb76a31bdc02649eb44e93a8e4f4cfcdbe8 Mon Sep 17 00:00:00 2001
From: Evgeny Boger <[email protected]>
Date: Wed, 17 Nov 2021 00:37:46 +0300
Subject: iio: adc: axp20x_adc: fix charging current reporting on AXP22x

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.

---
 drivers/iio/adc/axp20x_adc.c | 18 +++---------------
 1 file changed, 3 insertions(+), 15 deletions(-)

index 3e0c0233b431..df99f1365c39 100644
@@ -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;

2.34.1