[PATCH 4.4 105/146] iio: hudmidity: hdc100x: fix incorrect shifting and scaling

Greg Kroah-Hartman
2016-07-25T21:21:00Z

From: Matt Ranostay <mranostay@gmail.com>

commit 94bef000f1d4aa111f4ddda1482cf3b30ad069ce upstream.

Shifting sensor data to the right 2 bits was incorrect and caused the
scaling values + offsets to be invalid.

Reported-by: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Tested-by: Alison Schofield <amsfield22@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/iio/humidity/hdc100x.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

--- a/drivers/iio/humidity/hdc100x.c
+++ b/drivers/iio/humidity/hdc100x.c
@@ -164,14 +164,14 @@ static int hdc100x_get_measurement(struc
dev_err(&client->dev, "cannot read high byte measurement");
return ret;
}
- val = ret << 6;
+ val = ret << 8;

ret = i2c_smbus_read_byte(client);
if (ret < 0) {
dev_err(&client->dev, "cannot read low byte measurement");
return ret;
}
- val |= ret >> 2;
+ val |= ret;

return val;
}
@@ -212,17 +212,17 @@ static int hdc100x_read_raw(struct iio_d
case IIO_CHAN_INFO_SCALE:
if (chan->type == IIO_TEMP) {
*val = 165000;
- *val2 = 65536 >> 2;
+ *val2 = 65536;
return IIO_VAL_FRACTIONAL;
} else {
- *val = 0;
- *val2 = 10000;
- return IIO_VAL_INT_PLUS_MICRO;
+ *val = 100;
+ *val2 = 65536;
+ return IIO_VAL_FRACTIONAL;
}
break;
case IIO_CHAN_INFO_OFFSET:
- *val = -3971;
- *val2 = 879096;
+ *val = -15887;
+ *val2 = 515151;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;