iio: accel: kxsd9: Fix scaling bug

BugLink: http://bugs.launchpad.net/bugs/1627730
commit 307fe9dd11ae44d4f8881ee449a7cbac36e1f5de upstream.

All the scaling of the KXSD9 involves multiplication with a
fraction number < 1.

However the scaling value returned from IIO_INFO_SCALE was
unpredictable as only the micros of the value was assigned, and
not the integer part, resulting in scaling like this:

$cat in_accel_scale
-1057462640.011978

Fix this by assigning zero to the integer part.

Tested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/drivers/iio/accel/kxsd9.c b/drivers/iio/accel/kxsd9.c
index da5fb67ecb3465c7123352cf90db0f85166e8499..9d72d4bcf5e9b316034219bb1b880fc55a72c076 100644 (file)
--- a/drivers/iio/accel/kxsd9.c
+++ b/drivers/iio/accel/kxsd9.c
@@ -166,6 +166,7 @@ static int kxsd9_read_raw(struct iio_dev *indio_dev,
                ret = spi_w8r8(st->us, KXSD9_READ(KXSD9_REG_CTRL_C));
                if (ret < 0)
                        goto error_ret;
+               *val = 0;
                *val2 = kxsd9_micro_scales[ret & KXSD9_FS_MASK];
                ret = IIO_VAL_INT_PLUS_MICRO;
                break;