This is a note to let you know that I've just added the patch titled
drivers: iio: adc: ltc2497: fix LSB shift
to my char-misc git tree which can be found at git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git in the char-misc-linus branch.
The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)
The patch will hopefully also be merged in Linus's tree for the next -rc kernel release.
If you have any questions about this process, please let me know.
From 6327a930ab7bfa1ab33bcdffd5f5f4b1e7131504 Mon Sep 17 00:00:00 2001 From: Ian Ray ian.ray@ge.com Date: Fri, 27 Jan 2023 14:57:14 +0200 Subject: 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 --- drivers/iio/adc/ltc2497.c | 6 ++---- 1 file 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);