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, 41 insertions, 0 deletions

diff --git a/sound/firewire/cmp.h b/sound/firewire/cmp.h
new file mode 100644
index 000000000000..f47de08feb12
--- /dev/null
+++ b/sound/firewire/cmp.h
@@ -0,0 +1,41 @@
+#ifndef SOUND_FIREWIRE_CMP_H_INCLUDED
+#define SOUND_FIREWIRE_CMP_H_INCLUDED
+
+#include <linux/mutex.h>
+#include <linux/types.h>
+#include "iso-resources.h"
+
+struct fw_unit;
+
+/**
+ * struct cmp_connection - manages an isochronous connection to a device
+ * @speed: the connection's actual speed
+ *
+ * This structure manages (using CMP) an isochronous stream from the local
+ * computer to a device's input plug (iPCR).
+ *
+ * There is no corresponding oPCR created on the local computer, so it is not
+ * possible to overlay connections on top of this one.
+ */
+struct cmp_connection {
+        int speed;
+        /* private: */
+        bool connected;
+        struct mutex mutex;
+        struct fw_iso_resources resources;
+        __be32 last_pcr_value;
+        unsigned int pcr_index;
+        unsigned int max_speed;
+};
+
+int cmp_connection_init(struct cmp_connection *connection,
+                        struct fw_unit *unit,
+                        unsigned int ipcr_index);
+void cmp_connection_destroy(struct cmp_connection *connection);
+
+int cmp_connection_establish(struct cmp_connection *connection,
+                             unsigned int max_payload);
+int cmp_connection_update(struct cmp_connection *connection);
+void cmp_connection_break(struct cmp_connection *connection);
+
+#endif