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/amdtp.h b/sound/firewire/amdtp.h
new file mode 100644
index 0000000..02dc1a6
--- /dev/null
+++ b/sound/firewire/amdtp.h
@@ -0,0 +1,157 @@
+#ifndef SOUND_FIREWIRE_AMDTP_H_INCLUDED
+#define SOUND_FIREWIRE_AMDTP_H_INCLUDED
+
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+#include "packets-buffer.h"
+
+/**
+ * enum cip_out_flags - describes details of the streaming protocol
+ * @CIP_NONBLOCKING: In non-blocking mode, each packet contains
+ *	sample_rate/8000 samples, with rounding up or down to adjust
+ *	for clock skew and left-over fractional samples.  This should
+ *	be used if supported by the device.
+ */
+enum cip_out_flags {
+	CIP_NONBLOCKING = 0,
+};
+
+/**
+ * enum cip_sfc - a stream's sample rate
+ */
+enum cip_sfc {
+	CIP_SFC_32000  = 0,
+	CIP_SFC_44100  = 1,
+	CIP_SFC_48000  = 2,
+	CIP_SFC_88200  = 3,
+	CIP_SFC_96000  = 4,
+	CIP_SFC_176400 = 5,
+	CIP_SFC_192000 = 6,
+};
+
+#define AMDTP_OUT_PCM_FORMAT_BITS	(SNDRV_PCM_FMTBIT_S16 | \
+					 SNDRV_PCM_FMTBIT_S32)
+
+struct fw_unit;
+struct fw_iso_context;
+struct snd_pcm_substream;
+
+struct amdtp_out_stream {
+	struct fw_unit *unit;
+	enum cip_out_flags flags;
+	struct fw_iso_context *context;
+	struct mutex mutex;
+
+	enum cip_sfc sfc;
+	unsigned int data_block_quadlets;
+	unsigned int pcm_channels;
+	unsigned int midi_ports;
+	void (*transfer_samples)(struct amdtp_out_stream *s,
+				 struct snd_pcm_substream *pcm,
+				 __be32 *buffer, unsigned int frames);
+
+	unsigned int syt_interval;
+	unsigned int source_node_id_field;
+	struct iso_packets_buffer buffer;
+
+	struct snd_pcm_substream *pcm;
+
+	unsigned int packet_counter;
+	unsigned int data_block_counter;
+
+	unsigned int data_block_state;
+
+	unsigned int last_syt_offset;
+	unsigned int syt_offset_state;
+
+	unsigned int pcm_buffer_pointer;
+	unsigned int pcm_period_pointer;
+};
+
+int amdtp_out_stream_init(struct amdtp_out_stream *s, struct fw_unit *unit,
+			  enum cip_out_flags flags);
+void amdtp_out_stream_destroy(struct amdtp_out_stream *s);
+
+void amdtp_out_stream_set_rate(struct amdtp_out_stream *s, unsigned int rate);
+unsigned int amdtp_out_stream_get_max_payload(struct amdtp_out_stream *s);
+
+int amdtp_out_stream_start(struct amdtp_out_stream *s, int channel, int speed);
+void amdtp_out_stream_update(struct amdtp_out_stream *s);
+void amdtp_out_stream_stop(struct amdtp_out_stream *s);
+
+void amdtp_out_stream_set_pcm_format(struct amdtp_out_stream *s,
+				     snd_pcm_format_t format);
+void amdtp_out_stream_pcm_abort(struct amdtp_out_stream *s);
+
+/**
+ * amdtp_out_stream_set_pcm - configure format of PCM samples
+ * @s: the AMDTP output stream to be configured
+ * @pcm_channels: the number of PCM samples in each data block, to be encoded
+ *                as AM824 multi-bit linear audio
+ *
+ * This function must not be called while the stream is running.
+ */
+static inline void amdtp_out_stream_set_pcm(struct amdtp_out_stream *s,
+					    unsigned int pcm_channels)
+{
+	s->pcm_channels = pcm_channels;
+}
+
+/**
+ * amdtp_out_stream_set_midi - configure format of MIDI data
+ * @s: the AMDTP output stream to be configured
+ * @midi_ports: the number of MIDI ports (i.e., MPX-MIDI Data Channels)
+ *
+ * This function must not be called while the stream is running.
+ */
+static inline void amdtp_out_stream_set_midi(struct amdtp_out_stream *s,
+					     unsigned int midi_ports)
+{
+	s->midi_ports = midi_ports;
+}
+
+/**
+ * amdtp_out_stream_pcm_prepare - prepare PCM device for running
+ * @s: the AMDTP output stream
+ *
+ * This function should be called from the PCM device's .prepare callback.
+ */
+static inline void amdtp_out_stream_pcm_prepare(struct amdtp_out_stream *s)
+{
+	s->pcm_buffer_pointer = 0;
+	s->pcm_period_pointer = 0;
+}
+
+/**
+ * amdtp_out_stream_pcm_trigger - start/stop playback from a PCM device
+ * @s: the AMDTP output stream
+ * @pcm: the PCM device to be started, or %NULL to stop the current device
+ *
+ * Call this function on a running isochronous stream to enable the actual
+ * transmission of PCM data.  This function should be called from the PCM
+ * device's .trigger callback.
+ */
+static inline void amdtp_out_stream_pcm_trigger(struct amdtp_out_stream *s,
+						struct snd_pcm_substream *pcm)
+{
+	ACCESS_ONCE(s->pcm) = pcm;
+}
+
+/**
+ * amdtp_out_stream_pcm_pointer - get the PCM buffer position
+ * @s: the AMDTP output stream that transports the PCM data
+ *
+ * Returns the current buffer position, in frames.
+ */
+static inline unsigned long
+amdtp_out_stream_pcm_pointer(struct amdtp_out_stream *s)
+{
+	return ACCESS_ONCE(s->pcm_buffer_pointer);
+}
+
+static inline bool cip_sfc_is_base_44100(enum cip_sfc sfc)
+{
+	return sfc & 1;
+}
+
+#endif