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authorIan Ray <ian.ray@ge.com>2023-01-27 15:57:14 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-04-13 17:55:26 +0300
commitb3ea2426cc224394516a97faed2087f14721a915 (patch)
tree8c80f15f358b025dd5bcef14b5700e70abf725ea /drivers/iio
parent2fc86605075122e0b0744635e3e9f3c43ab2c44c (diff)
downloadlinux-b3ea2426cc224394516a97faed2087f14721a915.tar.xz
drivers: iio: adc: ltc2497: fix LSB shift
commit 6327a930ab7bfa1ab33bcdffd5f5f4b1e7131504 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/iio')
-rw-r--r--drivers/iio/adc/ltc2497.c6
1 files changed, 2 insertions, 4 deletions
diff --git a/drivers/iio/adc/ltc2497.c b/drivers/iio/adc/ltc2497.c
index 556f10dfb502..e1e14f5d237d 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);