staging: iio: ad2s1200: Add scaling factor for angular velocity channel

The sysfs iio ABI states radians per second is expected as the unit for
angular velocity, but the 12-bit angular velocity register has
revolution per seconds as its unit. So a scaling factor of approximately
2 * Pi is added to the angular velocity channel.

Signed-off-by: David Veenstra <davidjulianveenstra@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/staging/iio/resolver/ad2s1200.c b/drivers/staging/iio/resolver/ad2s1200.c
index 67d9747f88a69af5dd7b14ec9bb11bf9622197d8..7b8af558e92109885f1ddf4ac24e4b694ab74971 100644 (file)
--- a/drivers/staging/iio/resolver/ad2s1200.c
+++ b/drivers/staging/iio/resolver/ad2s1200.c
@@ -55,37 +55,55 @@ static int ad2s1200_read_raw(struct iio_dev *indio_dev,
        struct ad2s1200_state *st = iio_priv(indio_dev);
        int ret;
 
-       mutex_lock(&st->lock);
-       gpiod_set_value(st->sample, 0);
-
-       /* delay (6 * AD2S1200_TSCLK + 20) nano seconds */
-       udelay(1);
-       gpiod_set_value(st->sample, 1);
-       gpiod_set_value(st->rdvel, !!(chan->type == IIO_ANGL));
-
-       ret = spi_read(st->sdev, &st->rx, 2);
-       if (ret < 0) {
+       switch (m) {
+       case IIO_CHAN_INFO_SCALE:
+               switch (chan->type) {
+               case IIO_ANGL_VEL:
+                       /* 2 * Pi ~= 6.283185 */
+                       *val = 6;
+                       *val2 = 283185;
+                       return IIO_VAL_INT_PLUS_MICRO;
+               default:
+                       return -EINVAL;
+               }
+               break;
+       case IIO_CHAN_INFO_RAW:
+               mutex_lock(&st->lock);
+               gpiod_set_value(st->sample, 0);
+
+               /* delay (6 * AD2S1200_TSCLK + 20) nano seconds */
+               udelay(1);
+               gpiod_set_value(st->sample, 1);
+               gpiod_set_value(st->rdvel, !!(chan->type == IIO_ANGL));
+
+               ret = spi_read(st->sdev, &st->rx, 2);
+               if (ret < 0) {
+                       mutex_unlock(&st->lock);
+                       return ret;
+               }
+
+               switch (chan->type) {
+               case IIO_ANGL:
+                       *val = be16_to_cpup(&st->rx) >> 4;
+                       break;
+               case IIO_ANGL_VEL:
+                       *val = sign_extend32(be16_to_cpup(&st->rx) >> 4, 11);
+                       break;
+               default:
+                       mutex_unlock(&st->lock);
+                       return -EINVAL;
+               }
+
+               /* delay (2 * AD2S1200_TSCLK + 20) ns for sample pulse */
+               udelay(1);
                mutex_unlock(&st->lock);
-               return ret;
-       }
 
-       switch (chan->type) {
-       case IIO_ANGL:
-               *val = be16_to_cpup(&st->rx) >> 4;
-               break;
-       case IIO_ANGL_VEL:
-               *val = sign_extend32(be16_to_cpup(&st->rx) >> 4, 11);
-               break;
+               return IIO_VAL_INT;
        default:
-               mutex_unlock(&st->lock);
-               return -EINVAL;
+               break;
        }
 
-       /* delay (2 * AD2S1200_TSCLK + 20) ns for sample pulse */
-       udelay(1);
-       mutex_unlock(&st->lock);
-
-       return IIO_VAL_INT;
+       return -EINVAL;
 }
 
 static const struct iio_chan_spec ad2s1200_channels[] = {
@@ -99,6 +117,7 @@ static const struct iio_chan_spec ad2s1200_channels[] = {
                .indexed = 1,
                .channel = 0,
                .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+               .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
        }
 };