Hi Seb,
On Wed, Mar 27, 2013 at 09:17:43AM +0100, seb wrote:
> Event value is wrong. Should be in range -2048 to 2047, but is in range 0 to
> 4095.
> Use int8_t to int conversion and remove 0xfff mask.
>
> Signed-off-by: seb <sebastien.ro...@armadeus.com>
> ---
> drivers/input/misc/mma8450.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/input/misc/mma8450.c b/drivers/input/misc/mma8450.c
> index 480557f..c3781a1 100644
> --- a/drivers/input/misc/mma8450.c
> +++ b/drivers/input/misc/mma8450.c
> @@ -110,7 +110,7 @@ static void mma8450_poll(struct input_polled_dev *dev)
> struct mma8450 *m = dev->private;
> int x, y, z;
> int ret;
> - u8 buf[6];
> + int8_t buf[6];
>
> ret = mma8450_read(m, MMA8450_STATUS);
> if (ret < 0)
> @@ -119,13 +119,18 @@ static void mma8450_poll(struct input_polled_dev *dev)
> if (!(ret & MMA8450_STATUS_ZXYDR))
> return;
>
> - ret = mma8450_read_block(m, MMA8450_OUT_X_LSB, buf, sizeof(buf));
> + ret = mma8450_read_block(m, MMA8450_OUT_X_LSB, (u8*)buf, sizeof(buf));
> if (ret < 0)
> return;
>
> - x = ((buf[1] << 4) & 0xff0) | (buf[0] & 0xf);
> - y = ((buf[3] << 4) & 0xff0) | (buf[2] & 0xf);
> - z = ((buf[5] << 4) & 0xff0) | (buf[4] & 0xf);
> + /* convert 8 MSB from int8_t to int */
> + x = buf[1];
> + y = buf[3];
> + z = buf[5];
> + /* add 4 LSB */
> + x = (x << 4) | (buf[0] & 0xf);
> + y = (y << 4) | (buf[2] & 0xf);
> + z = (z << 4) | (buf[4] & 0xf);
Should we just say:
x = ((int)(s8)buf[1] << 4) | (buf[0] & 0xf);
y = ...
z = ...
and leave the rest as is?
Thanks.
--
Dmitry
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