[ALSA] Xilinx ML403 AC97 Controller Reference device driver

Add ALSA support for the opb_ac97_controller_ref_v1_00_a ip core found
in Xilinx' ML403 reference design.
Known issue: Currently this driver hits a WARN_ON_ONCE(1) statement in
kernel/irq/resend.c (line 70). According to Linus
(http://lkml.org/lkml/2007/8/5/5) this may be ignored, right? I haven't
had a look into this 'problem' yet.

Signed-off-by: Joachim Foerster <JOFT@gmx.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>

sound/drivers/Kconfig

@@ -120,4 +120,16 @@ config SND_PORTMAN2X4
 	  To compile this driver as a module, choose M here: the module
 	  will be called snd-portman2x4.
 
+config SND_ML403_AC97CR
+	tristate "Xilinx ML403 AC97 Controller Reference"
+	depends on SND && XILINX_VIRTEX
+	select SND_AC97_CODEC
+	help
+	  Say Y here to include support for the
+	  opb_ac97_controller_ref_v1_00_a ip core found in Xilinx' ML403
+	  reference design.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-ml403_ac97cr.
+
 endmenu

sound/drivers/Makefile

@@ -9,6 +9,7 @@ snd-mts64-objs := mts64.o
 snd-portman2x4-objs := portman2x4.o
 snd-serial-u16550-objs := serial-u16550.o
 snd-virmidi-objs := virmidi.o
+snd-ml403-ac97cr-objs := ml403-ac97cr.o pcm-indirect2.o
 
 # Toplevel Module Dependency
 obj-$(CONFIG_SND_DUMMY) += snd-dummy.o
@@ -17,5 +18,6 @@ obj-$(CONFIG_SND_SERIAL_U16550) += snd-serial-u16550.o
 obj-$(CONFIG_SND_MTPAV) += snd-mtpav.o
 obj-$(CONFIG_SND_MTS64) += snd-mts64.o
 obj-$(CONFIG_SND_PORTMAN2X4) += snd-portman2x4.o
+obj-$(CONFIG_SND_ML403_AC97CR) += snd-ml403-ac97cr.o
 
 obj-$(CONFIG_SND) += opl3/ opl4/ mpu401/ vx/