The ad5251/ad5252 devices have rdac1 and rdac3, but no rdac0. So make
sure we use the right channels so userspace gets correct data and not just
garbage.
Signed-off-by: steven miao <realmz6@gmail.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Cc: Michael Hennerich <michael.hennerich@analog.com> Cc: Chris Verges <chrisv@cyberswitching.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>