[PATCH v2 08/10] iio: adc: mcp3911: add support for phase

[Marcus Folkesson <marcus.folkesson@gmail.com>]

The MCP3911 incorporates a phase delay generator,
which ensures that the two ADCs are converting the
inputs with a fixed delay between them.
Expose it to userspace.

Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
---

Notes:
    v2:
        - Fix formatting (Andy Schevchenko)

 drivers/iio/adc/mcp3911.c | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/adc/mcp3911.c b/drivers/iio/adc/mcp3911.c
index ede1ad97ed4d..a0609d7663e1 100644
--- a/drivers/iio/adc/mcp3911.c
+++ b/drivers/iio/adc/mcp3911.c
@@ -155,6 +155,17 @@ static int mcp3911_read_raw(struct iio_dev *indio_dev,
 
 		ret = IIO_VAL_INT;
 		break;
+
+	case IIO_CHAN_INFO_PHASE:
+		ret = mcp3911_read(adc,
+				   MCP3911_REG_PHASE, val, 2);
+		if (ret)
+			goto out;
+
+		*val = sign_extend32(*val, 12);
+		ret = IIO_VAL_INT;
+		break;
+
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		ret = mcp3911_read(adc,
 				MCP3911_REG_CONFIG, val, 2);
@@ -225,6 +236,15 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
 				MCP3911_STATUSCOM_EN_OFFCAL, 2);
 		break;
 
+	case IIO_CHAN_INFO_PHASE:
+		if (val2 != 0 || val > 0xfff) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		/* Write phase */
+		ret = mcp3911_write(adc, MCP3911_REG_PHASE, val, 2);
+		break;
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		for (int i = 0; i < sizeof(mcp3911_osr_table); i++) {
 			if (val == mcp3911_osr_table[i]) {
@@ -248,7 +268,9 @@ static int mcp3911_write_raw(struct iio_dev *indio_dev,
 		.channel = idx,					\
 		.scan_index = idx,				\
 		.scan_index = idx,				\
-		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
+		.info_mask_shared_by_type =			\
+			BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO)|	\
+			BIT(IIO_CHAN_INFO_PHASE),		\
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
 			BIT(IIO_CHAN_INFO_OFFSET) |		\
 			BIT(IIO_CHAN_INFO_SCALE),		\
-- 
2.36.1