Re: [PATCH v2] staging:iio:accel:adis16240: sign extend function avoiding code duplication

From: Jonathan Cameron
Date: Sat Jun 16 2018 - 14:02:57 EST


On Tue, 12 Jun 2018 18:21:53 +0200
Karim Eshapa <karim.eshapa@xxxxxxxxx> wrote:

> Use sign_extend32 kernel function instead of code duplication,
> Safe also for 16 bit. and remove declaration of bits variable not needed.
>
> Signed-off-by: Karim Eshapa <karim.eshapa@xxxxxxxxx>

Please consider how a patch is applied and resend as a v3 which can actually
be applied. Test it (by applying it yourself) to make sure you have everything correct...

Jonathan

>
> >On Tue, 2018-06-12 at 01:38 +0200, Karim Eshapa wrote:
> >> Use sign_extend32 kernel function instead of code duplication.
> >> Safe also for 16 bit.
> >
> >Perhaps remove the bits declaration and assignments
> >and just use 9 directly.
> >
> >> diff --git a/drivers/staging/iio/accel/adis16240.c b/drivers/staging/iio/accel/adis16240.c
> >
> >> @@ -292,9 +292,7 @@ static int adis16240_read_raw(struct iio_dev *indio_dev,
> >> ret = adis_read_reg_16(st, addr, &val16);
> >> if (ret)
> >> return ret;
> >> - val16 &= (1 << bits) - 1;
> >> - val16 = (s16)(val16 << (16 - bits)) >> (16 - bits);
> >> - *val = val16;
> >> + *val = sign_extend32(val16, bits - 1);
> >> return IIO_VAL_INT;
> >> case IIO_CHAN_INFO_PEAK:
> >> bits = 10;
> >> @@ -302,9 +300,7 @@ static int adis16240_read_raw(struct iio_dev *indio_dev,
> >> ret = adis_read_reg_16(st, addr, &val16);
> >> if (ret)
> >> return ret;
> >> - val16 &= (1 << bits) - 1;
> >> - val16 = (s16)(val16 << (16 - bits)) >> (16 - bits);
> >> - *val = val16;
> >> + *val = sign_extend32(val16, bits - 1);
> >> return IIO_VAL_INT;
> >> }
> >> return -EINVAL;
> ---
> drivers/staging/iio/accel/adis16240.c | 11 ++---------
> 1 file changed, 2 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/staging/iio/accel/adis16240.c b/drivers/staging/iio/accel/adis16240.c
> index fff6d99089cc..24e525f1ef25 100644
> --- a/drivers/staging/iio/accel/adis16240.c
> +++ b/drivers/staging/iio/accel/adis16240.c
> @@ -250,7 +250,6 @@ static int adis16240_read_raw(struct iio_dev *indio_dev,
> {
> struct adis *st = iio_priv(indio_dev);
> int ret;
> - int bits;
> u8 addr;
> s16 val16;
>
> @@ -287,24 +286,18 @@ static int adis16240_read_raw(struct iio_dev *indio_dev,
> *val = 25000 / 244 - 0x133; /* 25 C = 0x133 */
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_CALIBBIAS:
> - bits = 10;
> addr = adis16240_addresses[chan->scan_index][0];
> ret = adis_read_reg_16(st, addr, &val16);
> if (ret)
> return ret;
> - val16 &= (1 << bits) - 1;
> - val16 = (s16)(val16 << (16 - bits)) >> (16 - bits);
> - *val = val16;
> + *val = sign_extend32(val16, 9);
> return IIO_VAL_INT;
> case IIO_CHAN_INFO_PEAK:
> - bits = 10;
> addr = adis16240_addresses[chan->scan_index][1];
> ret = adis_read_reg_16(st, addr, &val16);
> if (ret)
> return ret;
> - val16 &= (1 << bits) - 1;
> - val16 = (s16)(val16 << (16 - bits)) >> (16 - bits);
> - *val = val16;
> + *val = sign_extend32(val16, 9);
> return IIO_VAL_INT;
> }
> return -EINVAL;