ALSA: dice: support dual-wire stream format at 192 kHz

Change the AMDTP streaming code to handle the non-standard stream format
that DICE devices use at sample rates greater than 96 kHz.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>

4 files changed, 164 insertions, 67 deletions

diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c
index d56b8e736b7..a09c3b393c0 100644
--- a/sound/firewire/amdtp.c
+++ b/sound/firewire/amdtp.c
@@ -65,42 +65,66 @@ void amdtp_out_stream_destroy(struct amdtp_out_stream *s)
 }
 EXPORT_SYMBOL(amdtp_out_stream_destroy);
 
+unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = {
+	[CIP_SFC_32000]  =  8,
+	[CIP_SFC_44100]  =  8,
+	[CIP_SFC_48000]  =  8,
+	[CIP_SFC_88200]  = 16,
+	[CIP_SFC_96000]  = 16,
+	[CIP_SFC_176400] = 32,
+	[CIP_SFC_192000] = 32,
+};
+EXPORT_SYMBOL(amdtp_syt_intervals);
+
 /**
- * amdtp_out_stream_set_rate - set the sample rate
+ * amdtp_out_stream_set_parameters - set stream parameters
  * @s: the AMDTP output stream to configure
  * @rate: the sample rate
+ * @pcm_channels: the number of PCM samples in each data block, to be encoded
+ *                as AM824 multi-bit linear audio
+ * @midi_ports: the number of MIDI ports (i.e., MPX-MIDI Data Channels)
  *
- * The sample rate must be set before the stream is started, and must not be
+ * The parameters must be set before the stream is started, and must not be
  * changed while the stream is running.
  */
-void amdtp_out_stream_set_rate(struct amdtp_out_stream *s, unsigned int rate)
+void amdtp_out_stream_set_parameters(struct amdtp_out_stream *s,
+				     unsigned int rate,
+				     unsigned int pcm_channels,
+				     unsigned int midi_ports)
 {
-	static const struct {
-		unsigned int rate;
-		unsigned int syt_interval;
-	} rate_info[] = {
-		[CIP_SFC_32000]  = {  32000,  8, },
-		[CIP_SFC_44100]  = {  44100,  8, },
-		[CIP_SFC_48000]  = {  48000,  8, },
-		[CIP_SFC_88200]  = {  88200, 16, },
-		[CIP_SFC_96000]  = {  96000, 16, },
-		[CIP_SFC_176400] = { 176400, 32, },
-		[CIP_SFC_192000] = { 192000, 32, },
+	static const unsigned int rates[] = {
+		[CIP_SFC_32000]  =  32000,
+		[CIP_SFC_44100]  =  44100,
+		[CIP_SFC_48000]  =  48000,
+		[CIP_SFC_88200]  =  88200,
+		[CIP_SFC_96000]  =  96000,
+		[CIP_SFC_176400] = 176400,
+		[CIP_SFC_192000] = 192000,
 	};
 	unsigned int sfc;
 
 	if (WARN_ON(amdtp_out_stream_running(s)))
 		return;
 
-	for (sfc = 0; sfc < ARRAY_SIZE(rate_info); ++sfc)
-		if (rate_info[sfc].rate == rate)
+	for (sfc = 0; sfc < CIP_SFC_COUNT; ++sfc)
+		if (rates[sfc] == rate)
 			goto sfc_found;
 	WARN_ON(1);
 	return;
 
 sfc_found:
+	s->dual_wire = (s->flags & CIP_HI_DUALWIRE) && sfc > CIP_SFC_96000;
+	if (s->dual_wire) {
+		sfc -= 2;
+		rate /= 2;
+		pcm_channels *= 2;
+	}
 	s->sfc = sfc;
-	s->syt_interval = rate_info[sfc].syt_interval;
+	s->data_block_quadlets = pcm_channels + DIV_ROUND_UP(midi_ports, 8);
+	s->pcm_channels = pcm_channels;
+	s->midi_ports = midi_ports;
+
+	s->syt_interval = amdtp_syt_intervals[sfc];
 
 	/* default buffering in the device */
 	s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
@@ -108,21 +132,17 @@ sfc_found:
 		/* additional buffering needed to adjust for no-data packets */
 		s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate;
 }
-EXPORT_SYMBOL(amdtp_out_stream_set_rate);
+EXPORT_SYMBOL(amdtp_out_stream_set_parameters);
 
 /**
  * amdtp_out_stream_get_max_payload - get the stream's packet size
  * @s: the AMDTP output stream
  *
  * This function must not be called before the stream has been configured
- * with amdtp_out_stream_set_rate(), amdtp_out_stream_set_pcm(), and
- * amdtp_out_stream_set_midi().
+ * with amdtp_out_stream_set_parameters().
  */
 unsigned int amdtp_out_stream_get_max_payload(struct amdtp_out_stream *s)
 {
-	s->data_block_quadlets = s->pcm_channels;
-	s->data_block_quadlets += DIV_ROUND_UP(s->midi_ports, 8);
-
 	return 8 + s->syt_interval * s->data_block_quadlets * 4;
 }
 EXPORT_SYMBOL(amdtp_out_stream_get_max_payload);
@@ -133,14 +153,21 @@ static void amdtp_write_s16(struct amdtp_out_stream *s,
 static void amdtp_write_s32(struct amdtp_out_stream *s,
 			    struct snd_pcm_substream *pcm,
 			    __be32 *buffer, unsigned int frames);
+static void amdtp_write_s16_dualwire(struct amdtp_out_stream *s,
+				     struct snd_pcm_substream *pcm,
+				     __be32 *buffer, unsigned int frames);
+static void amdtp_write_s32_dualwire(struct amdtp_out_stream *s,
+				     struct snd_pcm_substream *pcm,
+				     __be32 *buffer, unsigned int frames);
 
 /**
  * amdtp_out_stream_set_pcm_format - set the PCM format
  * @s: the AMDTP output stream to configure
  * @format: the format of the ALSA PCM device
  *
- * The sample format must be set before the stream is started, and must not be
- * changed while the stream is running.
+ * The sample format must be set after the other paramters (rate/PCM channels/
+ * MIDI) and before the stream is started, and must not be changed while the
+ * stream is running.
  */
 void amdtp_out_stream_set_pcm_format(struct amdtp_out_stream *s,
 				     snd_pcm_format_t format)
@@ -153,10 +180,16 @@ void amdtp_out_stream_set_pcm_format(struct amdtp_out_stream *s,
 		WARN_ON(1);
 		/* fall through */
 	case SNDRV_PCM_FORMAT_S16:
-		s->transfer_samples = amdtp_write_s16;
+		if (s->dual_wire)
+			s->transfer_samples = amdtp_write_s16_dualwire;
+		else
+			s->transfer_samples = amdtp_write_s16;
 		break;
 	case SNDRV_PCM_FORMAT_S32:
-		s->transfer_samples = amdtp_write_s32;
+		if (s->dual_wire)
+			s->transfer_samples = amdtp_write_s32_dualwire;
+		else
+			s->transfer_samples = amdtp_write_s32;
 		break;
 	}
 }
@@ -305,6 +338,68 @@ static void amdtp_write_s16(struct amdtp_out_stream *s,
 	}
 }
 
+static void amdtp_write_s32_dualwire(struct amdtp_out_stream *s,
+				     struct snd_pcm_substream *pcm,
+				     __be32 *buffer, unsigned int frames)
+{
+	struct snd_pcm_runtime *runtime = pcm->runtime;
+	unsigned int channels, frame_adjust_1, frame_adjust_2, i, c;
+	const u32 *src;
+
+	channels = s->pcm_channels;
+	src = (void *)runtime->dma_area +
+			s->pcm_buffer_pointer * (runtime->frame_bits / 8);
+	frame_adjust_1 = channels - 1;
+	frame_adjust_2 = 1 - (s->data_block_quadlets - channels);
+
+	channels /= 2;
+	for (i = 0; i < frames; ++i) {
+		for (c = 0; c < channels; ++c) {
+			*buffer = cpu_to_be32((*src >> 8) | 0x40000000);
+			src++;
+			buffer += 2;
+		}
+		buffer -= frame_adjust_1;
+		for (c = 0; c < channels; ++c) {
+			*buffer = cpu_to_be32((*src >> 8) | 0x40000000);
+			src++;
+			buffer += 2;
+		}
+		buffer -= frame_adjust_2;
+	}
+}
+
+static void amdtp_write_s16_dualwire(struct amdtp_out_stream *s,
+				     struct snd_pcm_substream *pcm,
+				     __be32 *buffer, unsigned int frames)
+{
+	struct snd_pcm_runtime *runtime = pcm->runtime;
+	unsigned int channels, frame_adjust_1, frame_adjust_2, i, c;
+	const u16 *src;
+
+	channels = s->pcm_channels;
+	src = (void *)runtime->dma_area +
+			s->pcm_buffer_pointer * (runtime->frame_bits / 8);
+	frame_adjust_1 = channels - 1;
+	frame_adjust_2 = 1 - (s->data_block_quadlets - channels);
+
+	channels /= 2;
+	for (i = 0; i < frames; ++i) {
+		for (c = 0; c < channels; ++c) {
+			*buffer = cpu_to_be32((*src << 8) | 0x40000000);
+			src++;
+			buffer += 2;
+		}
+		buffer -= frame_adjust_1;
+		for (c = 0; c < channels; ++c) {
+			*buffer = cpu_to_be32((*src << 8) | 0x40000000);
+			src++;
+			buffer += 2;
+		}
+		buffer -= frame_adjust_2;
+	}
+}
+
 static void amdtp_fill_pcm_silence(struct amdtp_out_stream *s,
 				   __be32 *buffer, unsigned int frames)
 {
@@ -390,6 +485,9 @@ static void queue_out_packet(struct amdtp_out_stream *s, unsigned int cycle)
 	s->packet_index = index;
 
 	if (pcm) {
+		if (s->dual_wire)
+			data_blocks *= 2;
+
 		ptr = s->pcm_buffer_pointer + data_blocks;
 		if (ptr >= pcm->runtime->buffer_size)
 			ptr -= pcm->runtime->buffer_size;
@@ -459,8 +557,7 @@ static int queue_initial_skip_packets(struct amdtp_out_stream *s)
  * @speed: firewire speed code
  *
  * The stream cannot be started until it has been configured with
- * amdtp_out_stream_set_rate(), amdtp_out_stream_set_pcm(),
- * amdtp_out_stream_set_midi(), and amdtp_out_stream_set_format();
+ * amdtp_out_stream_set_parameters() and amdtp_out_stream_set_pcm_format(),
  * and it must be started before any PCM or MIDI device can be started.
  */
 int amdtp_out_stream_start(struct amdtp_out_stream *s, int channel, int speed)
diff --git a/sound/firewire/amdtp.h b/sound/firewire/amdtp.h
index 28b1bf5891e..f3d03dd92c3 100644
--- a/sound/firewire/amdtp.h
+++ b/sound/firewire/amdtp.h
@@ -15,10 +15,15 @@
  * @CIP_BLOCKING: In blocking mode, each packet contains either zero or
  *	SYT_INTERVAL samples, with these two types alternating so that
  *	the overall sample rate comes out right.
+ * @CIP_HI_DUALWIRE: At rates above 96 kHz, pretend that the stream runs
+ *	at half the actual sample rate with twice the number of channels;
+ *	two samples of a channel are stored consecutively in the packet.
+ *	Requires blocking mode and SYT_INTERVAL-aligned PCM buffer size.
  */
 enum cip_out_flags {
 	CIP_NONBLOCKING	= 0x00,
 	CIP_BLOCKING	= 0x01,
+	CIP_HI_DUALWIRE	= 0x02,
 };
 
 /**
@@ -32,6 +37,7 @@ enum cip_sfc {
 	CIP_SFC_96000  = 4,
 	CIP_SFC_176400 = 5,
 	CIP_SFC_192000 = 6,
+	CIP_SFC_COUNT
 };
 
 #define AMDTP_OUT_PCM_FORMAT_BITS	(SNDRV_PCM_FMTBIT_S16 | \
@@ -48,6 +54,7 @@ struct amdtp_out_stream {
 	struct mutex mutex;
 
 	enum cip_sfc sfc;
+	bool dual_wire;
 	unsigned int data_block_quadlets;
 	unsigned int pcm_channels;
 	unsigned int midi_ports;
@@ -80,7 +87,10 @@ 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);
+void amdtp_out_stream_set_parameters(struct amdtp_out_stream *s,
+				     unsigned int rate,
+				     unsigned int pcm_channels,
+				     unsigned int midi_ports);
 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);
@@ -93,39 +103,14 @@ void amdtp_out_stream_pcm_prepare(struct amdtp_out_stream *s);
 unsigned long amdtp_out_stream_pcm_pointer(struct amdtp_out_stream *s);
 void amdtp_out_stream_pcm_abort(struct amdtp_out_stream *s);
 
+extern unsigned int amdtp_syt_intervals[CIP_SFC_COUNT];
+
 static inline bool amdtp_out_stream_running(struct amdtp_out_stream *s)
 {
 	return !IS_ERR(s->context);
 }
 
 /**
- * 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_streaming_error - check for streaming error
  * @s: the AMDTP output stream
  *
diff --git a/sound/firewire/dice.c b/sound/firewire/dice.c
index b4827ff45d6..8804e42a96c 100644
--- a/sound/firewire/dice.c
+++ b/sound/firewire/dice.c
@@ -375,7 +375,7 @@ static int dice_open(struct snd_pcm_substream *substream)
 	struct dice *dice = substream->private_data;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	__be32 clock_sel, number_audio, number_midi;
-	unsigned int rate;
+	unsigned int rate_index, rate;
 	int err;
 
 	err = dice_try_lock(dice);
@@ -387,12 +387,13 @@ static int dice_open(struct snd_pcm_substream *substream)
 				 &clock_sel, 4);
 	if (err < 0)
 		goto err_lock;
-	rate = (be32_to_cpu(clock_sel) & CLOCK_RATE_MASK) >> CLOCK_RATE_SHIFT;
-	if (rate >= ARRAY_SIZE(dice_rates)) {
+	rate_index = (be32_to_cpu(clock_sel) & CLOCK_RATE_MASK)
+							>> CLOCK_RATE_SHIFT;
+	if (rate_index >= ARRAY_SIZE(dice_rates)) {
 		err = -ENXIO;
 		goto err_lock;
 	}
-	rate = dice_rates[rate];
+	rate = dice_rates[rate_index];
 
 	err = snd_fw_transaction(dice->unit, TCODE_READ_QUADLET_REQUEST,
 				 rx_address(dice, RX_NUMBER_AUDIO),
@@ -413,9 +414,20 @@ static int dice_open(struct snd_pcm_substream *substream)
 	runtime->hw.channels_min = be32_to_cpu(number_audio);
 	runtime->hw.channels_max = be32_to_cpu(number_audio);
 
-	amdtp_out_stream_set_rate(&dice->stream, rate);
-	amdtp_out_stream_set_pcm(&dice->stream, be32_to_cpu(number_audio));
-	amdtp_out_stream_set_midi(&dice->stream, be32_to_cpu(number_midi));
+	amdtp_out_stream_set_parameters(&dice->stream, rate,
+					be32_to_cpu(number_audio),
+					be32_to_cpu(number_midi));
+
+	err = snd_pcm_hw_constraint_step(runtime, 0,
+					 SNDRV_PCM_HW_PARAM_PERIOD_SIZE,
+					 amdtp_syt_intervals[rate_index]);
+	if (err < 0)
+		goto err_lock;
+	err = snd_pcm_hw_constraint_step(runtime, 0,
+					 SNDRV_PCM_HW_PARAM_BUFFER_SIZE,
+					 amdtp_syt_intervals[rate_index]);
+	if (err < 0)
+		goto err_lock;
 
 	err = snd_pcm_hw_constraint_minmax(runtime,
 					   SNDRV_PCM_HW_PARAM_PERIOD_TIME,
@@ -993,7 +1005,8 @@ static int dice_probe(struct fw_unit *unit, const struct ieee1394_device_id *id)
 		goto err_notification_handler;
 	dice->resources.channels_mask = 0x00000000ffffffffuLL;
 
-	err = amdtp_out_stream_init(&dice->stream, unit, CIP_BLOCKING);
+	err = amdtp_out_stream_init(&dice->stream, unit,
+				    CIP_BLOCKING | CIP_HI_DUALWIRE);
 	if (err < 0)
 		goto err_resources;
 
diff --git a/sound/firewire/speakers.c b/sound/firewire/speakers.c
index 0ac56304baf..6a68caf1d04 100644
--- a/sound/firewire/speakers.c
+++ b/sound/firewire/speakers.c
@@ -245,8 +245,10 @@ static int fwspk_hw_params(struct snd_pcm_substream *substream,
 	if (err < 0)
 		goto error;
 
-	amdtp_out_stream_set_rate(&fwspk->stream, params_rate(hw_params));
-	amdtp_out_stream_set_pcm(&fwspk->stream, params_channels(hw_params));
+	amdtp_out_stream_set_parameters(&fwspk->stream,
+					params_rate(hw_params),
+					params_channels(hw_params),
+					0);
 
 	amdtp_out_stream_set_pcm_format(&fwspk->stream,
 					params_format(hw_params));