Apparently some firmware versions forget enabling the dual-edge bit,
snd-powermac did that too and even OSX does sometimes. This should fix
headphone plug detection on those machines.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
Signed-off-by: NJaroslav Kysela <perex@suse.cz>

This large patch adds all of snd-aoa.
Consisting of many modules, it currently replaces snd-powermac
for all layout-id based machines and handles many more (for
example new powerbooks and powermacs with digital output that
previously couldn't be used at all).
It also has support for all layout-IDs that Apple has (judging
from their Info.plist file) but not all are tested.
The driver currently has 2 known regressions over snd-powermac:
 * it doesn't handle powermac 7,2 and 7,3
 * it doesn't have a DRC control on snapper-based machines
I will fix those during the 2.6.18 development cycle.
Signed-off-by: NJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: NTakashi Iwai <tiwai@suse.de>