iio: adc: sc27xx: Add raw data support

The headset device will use channel 20 of ADC controller to detect events,
but it needs the raw ADC data to do conversion according to its own formula.

Thus we should configure the channel mask separately and configure channel
20 as IIO_CHAN_INFO_RAW, as well as adding raw data read support.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/adc/sc27xx_adc.c

@@ -273,6 +273,17 @@ static int sc27xx_adc_read_raw(struct iio_dev *indio_dev,
 	int ret, tmp;
 
 	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		mutex_lock(&indio_dev->mlock);
+		ret = sc27xx_adc_read(data, chan->channel, scale, &tmp);
+		mutex_unlock(&indio_dev->mlock);
+
+		if (ret)
+			return ret;
+
+		*val = tmp;
+		return IIO_VAL_INT;
+
 	case IIO_CHAN_INFO_PROCESSED:
 		mutex_lock(&indio_dev->mlock);
 		ret = sc27xx_adc_read_processed(data, chan->channel, scale,
@@ -315,48 +326,47 @@ static const struct iio_info sc27xx_info = {
 	.write_raw = &sc27xx_adc_write_raw,
 };
 
-#define SC27XX_ADC_CHANNEL(index) {				\
+#define SC27XX_ADC_CHANNEL(index, mask) {			\
 	.type = IIO_VOLTAGE,					\
 	.channel = index,					\
-	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |	\
-			      BIT(IIO_CHAN_INFO_SCALE),		\
+	.info_mask_separate = mask | BIT(IIO_CHAN_INFO_SCALE),	\
 	.datasheet_name = "CH##index",				\
 	.indexed = 1,						\
 }
 
 static const struct iio_chan_spec sc27xx_channels[] = {
-	SC27XX_ADC_CHANNEL(0),
-	SC27XX_ADC_CHANNEL(1),
-	SC27XX_ADC_CHANNEL(2),
-	SC27XX_ADC_CHANNEL(3),
-	SC27XX_ADC_CHANNEL(4),
-	SC27XX_ADC_CHANNEL(5),
-	SC27XX_ADC_CHANNEL(6),
-	SC27XX_ADC_CHANNEL(7),
-	SC27XX_ADC_CHANNEL(8),
-	SC27XX_ADC_CHANNEL(9),
-	SC27XX_ADC_CHANNEL(10),
-	SC27XX_ADC_CHANNEL(11),
-	SC27XX_ADC_CHANNEL(12),
-	SC27XX_ADC_CHANNEL(13),
-	SC27XX_ADC_CHANNEL(14),
-	SC27XX_ADC_CHANNEL(15),
-	SC27XX_ADC_CHANNEL(16),
-	SC27XX_ADC_CHANNEL(17),
-	SC27XX_ADC_CHANNEL(18),
-	SC27XX_ADC_CHANNEL(19),
-	SC27XX_ADC_CHANNEL(20),
-	SC27XX_ADC_CHANNEL(21),
-	SC27XX_ADC_CHANNEL(22),
-	SC27XX_ADC_CHANNEL(23),
-	SC27XX_ADC_CHANNEL(24),
-	SC27XX_ADC_CHANNEL(25),
-	SC27XX_ADC_CHANNEL(26),
-	SC27XX_ADC_CHANNEL(27),
-	SC27XX_ADC_CHANNEL(28),
-	SC27XX_ADC_CHANNEL(29),
-	SC27XX_ADC_CHANNEL(30),
-	SC27XX_ADC_CHANNEL(31),
+	SC27XX_ADC_CHANNEL(0, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(1, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(2, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(3, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(4, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(5, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(6, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(7, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(8, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(9, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(10, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(11, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(12, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(13, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(14, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(15, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(16, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(17, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(18, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(19, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(20, BIT(IIO_CHAN_INFO_RAW)),
+	SC27XX_ADC_CHANNEL(21, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(22, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(23, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(24, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(25, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(26, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(27, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(28, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(29, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(30, BIT(IIO_CHAN_INFO_PROCESSED)),
+	SC27XX_ADC_CHANNEL(31, BIT(IIO_CHAN_INFO_PROCESSED)),
 };
 
 static int sc27xx_adc_enable(struct sc27xx_adc_data *data)