[PATCH 7/8] iio: adc: rzt2h: Use scan type for ADC scale

[Prabhakar]

From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

Prepare the driver for RZ/V2H(P) support, where the ADC supports both
12-bit and 8-bit conversion resolutions.

Use the current IIO scan type to determine the ADC resolution when
reporting the scale instead of assuming a fixed 12-bit resolution.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
---
 drivers/iio/adc/rzt2h_adc.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/adc/rzt2h_adc.c b/drivers/iio/adc/rzt2h_adc.c
index 26028856b175..953736b5475a 100644
--- a/drivers/iio/adc/rzt2h_adc.c
+++ b/drivers/iio/adc/rzt2h_adc.c
@@ -59,6 +59,8 @@
 					 RZT2H_ADC_DMA_PERIOD_SAMPLES)
 #define RZT2H_ADC_STOP_CYCLES		2
 
+#define RZT2H_ADC_VREF_MV		1800
+
 #define RZT2H_ADC_FEATURE_CALIBRATION	BIT(0)
 #define RZT2H_ADC_FEATURE_SAMPLE_STATE	BIT(1)
 
@@ -529,10 +531,18 @@ static int rzt2h_adc_read_raw(struct iio_dev *indio_dev,
 
 		return rzt2h_adc_read_single(adc, chan->channel, val);
 	}
-	case IIO_CHAN_INFO_SCALE:
-		*val = 1800;
-		*val2 = 12;
+	case IIO_CHAN_INFO_SCALE: {
+		const struct iio_scan_type *scan_type;
+
+		scan_type = iio_get_current_scan_type(indio_dev, chan);
+		if (IS_ERR(scan_type))
+			return PTR_ERR(scan_type);
+
+		*val = RZT2H_ADC_VREF_MV;
+		*val2 = scan_type->realbits;
+
 		return IIO_VAL_FRACTIONAL_LOG2;
+	}
 	case IIO_CHAN_INFO_SAMP_FREQ:
 		*val = adc->chip_info->sst_to_freq(adc, adc->sst[chan->channel]);
 		return IIO_VAL_INT;
-- 
2.55.0