patch "iio: mtk-auxadc: fix case IIO_CHAN_INFO_PROCESSED" added to staging-linus

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

iio: mtk-auxadc: fix case IIO_CHAN_INFO_PROCESSED

to my staging git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging.git
in the staging-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 c2980c64c7fd4585d684574c92d1624d44961edd Mon Sep 17 00:00:00 2001
From: Hui Liu <[email protected]>
Date: Sun, 26 Sep 2021 15:30:28 +0800
Subject: iio: mtk-auxadc: fix case IIO_CHAN_INFO_PROCESSED

The previous driver does't apply the necessary scaling to take the voltage range into account.
We change readback value from raw data to input voltage to fix case IIO_CHAN_INFO_PROCESSED.

---
 drivers/iio/adc/mt6577_auxadc.c | 8 ++++++++
 1 file changed, 8 insertions(+)

index 79c1dd68b909..d4fccd52ef08 100644
@@ -82,6 +82,10 @@ static const struct iio_chan_spec mt6577_auxadc_iio_channels[] = {
 	MT6577_AUXADC_CHANNEL(15),
 };
 
+/* For Voltage calculation */
+#define VOLTAGE_FULL_RANGE  1500	/* VA voltage */
+#define AUXADC_PRECISE      4096	/* 12 bits */
+
 static int mt_auxadc_get_cali_data(int rawdata, bool enable_cali)
 {
 	return rawdata;

@@ -191,6 +195,10 @@ static int mt6577_auxadc_read_raw(struct iio_dev *indio_dev,
 		}
 		if (adc_dev->dev_comp->sample_data_cali)
 			*val = mt_auxadc_get_cali_data(*val, true);
+
+		/* Convert adc raw data to voltage: 0 - 1500 mV */
+		*val = *val * VOLTAGE_FULL_RANGE / AUXADC_PRECISE;
+
 		return IIO_VAL_INT;
 
 	default:

2.33.0