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>

1 files changed, 19 insertions, 0 deletions

diff --git a/sound/firewire/lib.h b/sound/firewire/lib.h
new file mode 100644
index 000000000000..064f3fd9ab06
--- /dev/null
+++ b/sound/firewire/lib.h
@@ -0,0 +1,19 @@
+#ifndef SOUND_FIREWIRE_LIB_H_INCLUDED
+#define SOUND_FIREWIRE_LIB_H_INCLUDED
+
+#include <linux/firewire-constants.h>
+#include <linux/types.h>
+
+struct fw_unit;
+
+int snd_fw_transaction(struct fw_unit *unit, int tcode,
+                       u64 offset, void *buffer, size_t length);
+const char *rcode_string(unsigned int rcode);
+
+/* returns true if retrying the transaction would not make sense */
+static inline bool rcode_is_permanent_error(int rcode)
+{
+        return rcode == RCODE_TYPE_ERROR || rcode == RCODE_ADDRESS_ERROR;
+}
+
+#endif