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>

1 files changed, 126 insertions, 29 deletions

diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c
index d56b8e736b7d..a09c3b393c0b 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)