stable inclusion
from stable-5.10.26
commit d894acab284426d1500f84dca4bfc4634711b28a
bugzilla: 51363

--------------------------------

commit f890987f upstream.

Fixes a wrong bit mask used for the ADC's result, which was caused by an
improper usage of the GENMASK() macro. The bits higher than ADC's
resolution are undefined and if not masked out correctly, a wrong result
can be given. The GENMASK() macro indexing is zero based, so the mask has
to go from [resolution - 1 , 0].

Fixes: 7f40e061 ("iio:adc:ad7949: Add AD7949 ADC driver family")
Signed-off-by: NWilfried Wessner <wilfried.wessner@gmail.com>
Reviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: NCharles-Antoine Couret <charles-antoine.couret@essensium.com>
Cc: <Stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210208142705.GA51260@ubuntuSigned-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: N  Weilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>