iio: dht11: Use new function ktime_get_resolution_ns()
This cleans up the most ugly workaround in this driver. There are no
functional changes yet in the decoding algorithm, but we improve the
following things:
* Get rid of spurious warning messages on systems with fast HRTIMER.
* If the clock is not fast enough for decoding to work, we give
up immediately.
* In that case we return EAGAIN instead of EIO, so it's easier to
discriminate causes of failure.
Returning EAGAIN is somewhat controversial: It's technically correct
as a faster clock might become available. OTOH once all clocks are
enabled this is a permanent error. There is no ECLOCKTOOSLOW error
code.
Signed-off-by: Harald Geyer <harald@ccbib.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
1 file changed