When doing register reads, it is possible for there to be a stale
data ready bit set which will cause subsequent reads to return
prematurely with incorrect data.  This patch fixes the issues by
ensuring stale data is cleared before starting another transaction.
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NJon Smirl <jonsmirl@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The function signature for spin_event_timeout() has changed in version V9.
Adjust the mpc5200 AC97 driver to use the new function.
Signed-off-by: NJon Smirl <jonsmirl@gmail.com>
Acked-by: NTimur Tabi <timur@freescale.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

I've implemented retries for when the AC97 hardware doesn't reset on
first try. About 10% of the time both the Efika and pcm030 AC97 codecs
don't reset on first try and need to be poked multiple times.  Failure
is indicated by not having the link clock start ticking. Every once in
a while even five pokes won't get the link started and I have to power
cycle.
Signed-off-by: NJon Smirl <jonsmirl@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>