ALSA: add LaCie FireWire Speakers/Griffin FireWave Surround driver

Add a driver for two playback-only FireWire devices based on the OXFW970
chip.

v2: better AMDTP API abstraction; fix fw_unit leak; small fixes
v3: cache the iPCR value
v4: FireWave constraints; fix fw_device reference counting;
    fix PCR caching; small changes and fixes
v5: volume/mute support; fix crashing due to pcm stop races
v6: fix build; one-channel volume for LaCie
v7: use signed values to make volume (range checks) work; fix function
    block IDs for volume/mute; always use channel 0 for LaCie volume

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Tested-by: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/firewire/Kconfig b/sound/firewire/Kconfig
new file mode 100644
index 0000000..e486f48
--- /dev/null
+++ b/sound/firewire/Kconfig
@@ -0,0 +1,25 @@
+menuconfig SND_FIREWIRE
+	bool "FireWire sound devices"
+	depends on FIREWIRE
+	default y
+	help
+	  Support for IEEE-1394/FireWire/iLink sound devices.
+
+if SND_FIREWIRE && FIREWIRE
+
+config SND_FIREWIRE_LIB
+	tristate
+	depends on SND_PCM
+
+config SND_FIREWIRE_SPEAKERS
+	tristate "FireWire speakers"
+	select SND_PCM
+	select SND_FIREWIRE_LIB
+	help
+	  Say Y here to include support for the Griffin FireWave Surround
+	  and the LaCie FireWire Speakers.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-firewire-speakers.
+
+endif # SND_FIREWIRE