[PATCH v3 5/6] staging:iio:ad2s90: Add IIO_CHAN_INFO_SCALE to channel spec and read_raw

[Matheus Tavares]

This patch adds the IIO_CHAN_INFO_SCALE mask to ad2s90_chan and
implements the relative read behavior at ad2s90_read_raw.

Signed-off-by: Victor Colombo <victorcolo...@gmail.com>
Signed-off-by: Matheus Tavares <matheus.bernard...@usp.br>
---
 drivers/staging/iio/resolver/ad2s90.c | 30 +++++++++++++++++++--------
 1 file changed, 21 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/iio/resolver/ad2s90.c 
b/drivers/staging/iio/resolver/ad2s90.c
index 8f79cccf4814..9c168b7410d0 100644
--- a/drivers/staging/iio/resolver/ad2s90.c
+++ b/drivers/staging/iio/resolver/ad2s90.c
@@ -34,17 +34,29 @@ static int ad2s90_read_raw(struct iio_dev *indio_dev,
        int ret;
        struct ad2s90_state *st = iio_priv(indio_dev);
 
-       mutex_lock(&st->lock);
-       ret = spi_read(st->sdev, st->rx, 2);
-       if (ret < 0) {
+       switch (m) {
+       case IIO_CHAN_INFO_SCALE:
+               /* 2 * Pi / 2^12 */
+               *val = 6283; /* mV */
+               *val2 = 12;
+               return IIO_VAL_FRACTIONAL_LOG2;
+       case IIO_CHAN_INFO_RAW:
+               mutex_lock(&st->lock);
+               ret = spi_read(st->sdev, st->rx, 2);
+               if (ret < 0) {
+                       mutex_unlock(&st->lock);
+                       return ret;
+               }
+               *val = (((u16)(st->rx[0])) << 4) | ((st->rx[1] & 0xF0) >> 4);
+
                mutex_unlock(&st->lock);
-               return ret;
-       }
-       *val = (((u16)(st->rx[0])) << 4) | ((st->rx[1] & 0xF0) >> 4);
 
-       mutex_unlock(&st->lock);
+               return IIO_VAL_INT;
+       default:
+               break;
+       }
 
-       return IIO_VAL_INT;
+       return -EINVAL;
 }
 
 static const struct iio_info ad2s90_info = {
@@ -55,7 +67,7 @@ static const struct iio_chan_spec ad2s90_chan = {
        .type = IIO_ANGL,
        .indexed = 1,
        .channel = 0,
-       .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+       .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
 };
 
 static int ad2s90_probe(struct spi_device *spi)
-- 
2.18.0