A recent change in clang strengthened its -Wbitfield-constant-conversion
to warn when 1 is assigned to a 1-bit signed integer bitfield, as it can
only be 0 or -1, not 1:
sound/soc/atmel/mchp-spdiftx.c:505:20: error: implicit truncation from 'int' to bit-field changes value from 1 to -1 [-Werror,-Wbitfield-constant-conversion]
dev->gclk_enabled = 1;
^ ~
1 error generated.
The actual value of the field is never checked, just that it is not
zero, so there is not a real bug here. However, it is simple enough to
silence the warning by making the bitfield unsigned, which matches the
mchp-spdifrx driver.