diff options
| author | Ian Ray <ian.ray@ge.com> | 2023-01-27 14:57:14 +0200 |
|---|---|---|
| committer | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2023-01-28 17:58:56 +0000 |
| commit | 6327a930ab7bfa1ab33bcdffd5f5f4b1e7131504 (patch) | |
| tree | 9a342c4171b0629e3225623edc76a4f11cf3edbe /drivers/iio/adc | |
| parent | 701c875aded880013aacac608832995c4b052257 (diff) | |
| download | lwn-6327a930ab7bfa1ab33bcdffd5f5f4b1e7131504.tar.gz lwn-6327a930ab7bfa1ab33bcdffd5f5f4b1e7131504.zip | |
drivers: iio: adc: ltc2497: fix LSB shift
Correct the "sub_lsb" shift for the ltc2497 and drop the sub_lsb element
which is now constant.
An earlier version of the code shifted by 14 but this was a consequence
of reading three bytes into a __be32 buffer and using be32_to_cpu(), so
eight extra bits needed to be skipped. Now we use get_unaligned_be24()
and thus the additional skip is wrong.
Fixes: 2187cfeb3626 ("drivers: iio: adc: ltc2497: LTC2499 support")
Signed-off-by: Ian Ray <ian.ray@ge.com>
Link: https://lore.kernel.org/r/20230127125714.44608-1-ian.ray@ge.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Diffstat (limited to 'drivers/iio/adc')
| -rw-r--r-- | drivers/iio/adc/ltc2497.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/drivers/iio/adc/ltc2497.c b/drivers/iio/adc/ltc2497.c index 17370c5eb6fe..ec198c6f13d6 100644 --- a/drivers/iio/adc/ltc2497.c +++ b/drivers/iio/adc/ltc2497.c @@ -28,7 +28,6 @@ struct ltc2497_driverdata { struct ltc2497core_driverdata common_ddata; struct i2c_client *client; u32 recv_size; - u32 sub_lsb; /* * DMA (thus cache coherency maintenance) may require the * transfer buffers to live in their own cache lines. @@ -65,10 +64,10 @@ static int ltc2497_result_and_measure(struct ltc2497core_driverdata *ddata, * equivalent to a sign extension. */ if (st->recv_size == 3) { - *val = (get_unaligned_be24(st->data.d8) >> st->sub_lsb) + *val = (get_unaligned_be24(st->data.d8) >> 6) - BIT(ddata->chip_info->resolution + 1); } else { - *val = (be32_to_cpu(st->data.d32) >> st->sub_lsb) + *val = (be32_to_cpu(st->data.d32) >> 6) - BIT(ddata->chip_info->resolution + 1); } @@ -122,7 +121,6 @@ static int ltc2497_probe(struct i2c_client *client) st->common_ddata.chip_info = chip_info; resolution = chip_info->resolution; - st->sub_lsb = 31 - (resolution + 1); st->recv_size = BITS_TO_BYTES(resolution) + 1; return ltc2497core_probe(dev, indio_dev); |