iio: mpl3115: Use scan_type.shift and realbit in mpl3115_read_raw

When processing raw data using channel scan_type.shift as source of
trust to shift data appropriately.
When processing the temperature channel, use a 16bit big endian variable
as buffer to increase conversion readability.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Link: https://lore.kernel.org/r/20211104082413.3681212-14-gwendal@chromium.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/pressure/mpl3115.c b/drivers/iio/pressure/mpl3115.c
index 1eb9e7b..e95b9a5 100644 (file)
--- a/drivers/iio/pressure/mpl3115.c
+++ b/drivers/iio/pressure/mpl3115.c
@@ -74,7 +74,6 @@ static int mpl3115_read_raw(struct iio_dev *indio_dev,
                            int *val, int *val2, long mask)
 {
        struct mpl3115_data *data = iio_priv(indio_dev);
-       __be32 tmp = 0;
        int ret;
 
        switch (mask) {
@@ -84,7 +83,9 @@ static int mpl3115_read_raw(struct iio_dev *indio_dev,
                        return ret;
 
                switch (chan->type) {
-               case IIO_PRESSURE: /* in 0.25 pascal / LSB */
+               case IIO_PRESSURE: { /* in 0.25 pascal / LSB */
+                       __be32 tmp = 0;
+
                        mutex_lock(&data->lock);
                        ret = mpl3115_request(data);
                        if (ret < 0) {
@@ -96,10 +97,13 @@ static int mpl3115_read_raw(struct iio_dev *indio_dev,
                        mutex_unlock(&data->lock);
                        if (ret < 0)
                                break;
-                       *val = be32_to_cpu(tmp) >> 12;
+                       *val = be32_to_cpu(tmp) >> chan->scan_type.shift;
                        ret = IIO_VAL_INT;
                        break;
-               case IIO_TEMP: /* in 0.0625 celsius / LSB */
+               }
+               case IIO_TEMP: { /* in 0.0625 celsius / LSB */
+                       __be16 tmp;
+
                        mutex_lock(&data->lock);
                        ret = mpl3115_request(data);
                        if (ret < 0) {
@@ -111,9 +115,11 @@ static int mpl3115_read_raw(struct iio_dev *indio_dev,
                        mutex_unlock(&data->lock);
                        if (ret < 0)
                                break;
-                       *val = sign_extend32(be32_to_cpu(tmp) >> 20, 11);
+                       *val = sign_extend32(be16_to_cpu(tmp) >> chan->scan_type.shift,
+                                            chan->scan_type.realbits - 1);
                        ret = IIO_VAL_INT;
                        break;
+               }
                default:
                        ret = -EINVAL;
                        break;