iio: adc: ad7944: mask high bits on direct read

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commit 7cdfbc0113 upstream.

Apply a mask to the raw value received over the SPI bus for unsigned
direct reads. As we found recently, SPI controllers may not set unused
bits to 0 when reading with bits_per_word != {8,16,32}. The ad7944 uses
bits_per_word of 14 and 18, so we need to mask the value to be sure we
returning the correct value to userspace during a direct read.

Fixes: d1efcf8871 ("iio: adc: ad7944: add driver for AD7944/AD7985/AD7986")
Signed-off-by: David Lechner <dlechner@baylibre.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://patch.msgid.link/20250505-iio-adc-ad7944-max-high-bits-on-direct-read-v1-1-b173facceefe@baylibre.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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David Lechner 2025-05-05 13:28:40 -05:00 • committed by Greg Kroah-Hartman

parent ea66a9effa

commit aaa25db0b8

1 changed files with 2 additions and 0 deletions

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drivers/iio/adc/ad7944.c

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