[linux-block.git] / sound / firewire / motu / amdtp-motu.c

/*
 * amdtp-motu.c - a part of driver for MOTU FireWire series
 *
 * Copyright (c) 2015-2017 Takashi Sakamoto <o-takashi@sakamocchi.jp>
 *
 * Licensed under the terms of the GNU General Public License, version 2.
 */

#include <linux/slab.h>
#include <sound/pcm.h>
#include "motu.h"

#define CREATE_TRACE_POINTS
#include "amdtp-motu-trace.h"

#define CIP_FMT_MOTU		0x02
#define CIP_FMT_MOTU_TX_V3	0x22
#define MOTU_FDF_AM824		0x22

/*
 * Nominally 3125 bytes/second, but the MIDI port's clock might be
 * 1% too slow, and the bus clock 100 ppm too fast.
 */
#define MIDI_BYTES_PER_SECOND	3093

struct amdtp_motu {
	/* For timestamp processing.  */
	unsigned int quotient_ticks_per_event;
	unsigned int remainder_ticks_per_event;
	unsigned int next_ticks;
	unsigned int next_accumulated;
	unsigned int next_cycles;
	unsigned int next_seconds;

	unsigned int pcm_chunks;
	unsigned int pcm_byte_offset;

	struct snd_rawmidi_substream *midi;
	unsigned int midi_ports;
	unsigned int midi_flag_offset;
	unsigned int midi_byte_offset;

	int midi_db_count;
	unsigned int midi_db_interval;
};

int amdtp_motu_set_parameters(struct amdtp_stream *s, unsigned int rate,
			      unsigned int midi_ports,
			      struct snd_motu_packet_format *formats)
{
	static const struct {
		unsigned int quotient_ticks_per_event;
		unsigned int remainder_ticks_per_event;
	} params[] = {
		[CIP_SFC_44100]  = { 557, 123 },
		[CIP_SFC_48000]  = { 512,   0 },
		[CIP_SFC_88200]  = { 278, 282 },
		[CIP_SFC_96000]  = { 256,   0 },
		[CIP_SFC_176400] = { 139, 141 },
		[CIP_SFC_192000] = { 128,   0 },
	};
	struct amdtp_motu *p = s->protocol;
	unsigned int pcm_chunks, data_chunks, data_block_quadlets;
	unsigned int delay;
	unsigned int mode;
	int i, err;

	if (amdtp_stream_running(s))
		return -EBUSY;

	for (i = 0; i < ARRAY_SIZE(snd_motu_clock_rates); ++i) {
		if (snd_motu_clock_rates[i] == rate) {
			mode = i >> 1;
			break;
		}
	}
	if (i == ARRAY_SIZE(snd_motu_clock_rates))
		return -EINVAL;

	pcm_chunks = formats->fixed_part_pcm_chunks[mode] +
		     formats->differed_part_pcm_chunks[mode];
	data_chunks = formats->msg_chunks + pcm_chunks;

	/*
	 * Each data block includes SPH in its head. Data chunks follow with
	 * 3 byte alignment. Padding follows with zero to conform to quadlet
	 * alignment.
	 */
	data_block_quadlets = 1 + DIV_ROUND_UP(data_chunks * 3, 4);

	err = amdtp_stream_set_parameters(s, rate, data_block_quadlets);
	if (err < 0)
		return err;

	p->pcm_chunks = pcm_chunks;
	p->pcm_byte_offset = formats->pcm_byte_offset;

	p->midi_ports = midi_ports;
	p->midi_flag_offset = formats->midi_flag_offset;
	p->midi_byte_offset = formats->midi_byte_offset;

	p->midi_db_count = 0;
	p->midi_db_interval = rate / MIDI_BYTES_PER_SECOND;

	/* IEEE 1394 bus requires. */
	delay = 0x2e00;

	/* For no-data or empty packets to adjust PCM sampling frequency. */
	delay += 8000 * 3072 * s->syt_interval / rate;

	p->next_seconds = 0;
	p->next_cycles = delay / 3072;
	p->quotient_ticks_per_event = params[s->sfc].quotient_ticks_per_event;
	p->remainder_ticks_per_event = params[s->sfc].remainder_ticks_per_event;
	p->next_ticks = delay % 3072;
	p->next_accumulated = 0;

	return 0;
}

static void read_pcm_s32(struct amdtp_stream *s,
			 struct snd_pcm_runtime *runtime,
			 __be32 *buffer, unsigned int data_blocks)
{
	struct amdtp_motu *p = s->protocol;
	unsigned int channels, remaining_frames, i, c;
	u8 *byte;
	u32 *dst;

	channels = p->pcm_chunks;
	dst = (void *)runtime->dma_area +
			frames_to_bytes(runtime, s->pcm_buffer_pointer);
	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;

	for (i = 0; i < data_blocks; ++i) {
		byte = (u8 *)buffer + p->pcm_byte_offset;

		for (c = 0; c < channels; ++c) {
			*dst = (byte[0] << 24) | (byte[1] << 16) | byte[2];
			byte += 3;
			dst++;
		}
		buffer += s->data_block_quadlets;
		if (--remaining_frames == 0)
			dst = (void *)runtime->dma_area;
	}
}

static void write_pcm_s32(struct amdtp_stream *s,
			  struct snd_pcm_runtime *runtime,
			  __be32 *buffer, unsigned int data_blocks)
{
	struct amdtp_motu *p = s->protocol;
	unsigned int channels, remaining_frames, i, c;
	u8 *byte;
	const u32 *src;

	channels = p->pcm_chunks;
	src = (void *)runtime->dma_area +
			frames_to_bytes(runtime, s->pcm_buffer_pointer);
	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;

	for (i = 0; i < data_blocks; ++i) {
		byte = (u8 *)buffer + p->pcm_byte_offset;

		for (c = 0; c < channels; ++c) {
			byte[0] = (*src >> 24) & 0xff;
			byte[1] = (*src >> 16) & 0xff;
			byte[2] = (*src >>  8) & 0xff;
			byte += 3;
			src++;
		}

		buffer += s->data_block_quadlets;
		if (--remaining_frames == 0)
			src = (void *)runtime->dma_area;
	}
}

static void write_pcm_silence(struct amdtp_stream *s, __be32 *buffer,
			      unsigned int data_blocks)
{
	struct amdtp_motu *p = s->protocol;
	unsigned int channels, i, c;
	u8 *byte;

	channels = p->pcm_chunks;

	for (i = 0; i < data_blocks; ++i) {
		byte = (u8 *)buffer + p->pcm_byte_offset;

		for (c = 0; c < channels; ++c) {
			byte[0] = 0;
			byte[1] = 0;
			byte[2] = 0;
			byte += 3;
		}

		buffer += s->data_block_quadlets;
	}
}

int amdtp_motu_add_pcm_hw_constraints(struct amdtp_stream *s,
				      struct snd_pcm_runtime *runtime)
{
	int err;

	/* TODO: how to set an constraint for exactly 24bit PCM sample? */
	err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
	if (err < 0)
		return err;

	return amdtp_stream_add_pcm_hw_constraints(s, runtime);
}

void amdtp_motu_midi_trigger(struct amdtp_stream *s, unsigned int port,
			     struct snd_rawmidi_substream *midi)
{
	struct amdtp_motu *p = s->protocol;

	if (port < p->midi_ports)
		WRITE_ONCE(p->midi, midi);
}

static void write_midi_messages(struct amdtp_stream *s, __be32 *buffer,
				unsigned int data_blocks)
{
	struct amdtp_motu *p = s->protocol;
	struct snd_rawmidi_substream *midi = READ_ONCE(p->midi);
	u8 *b;
	int i;

	for (i = 0; i < data_blocks; i++) {
		b = (u8 *)buffer;

		if (midi && p->midi_db_count == 0 &&
		    snd_rawmidi_transmit(midi, b + p->midi_byte_offset, 1) == 1) {
			b[p->midi_flag_offset] = 0x01;
		} else {
			b[p->midi_byte_offset] = 0x00;
			b[p->midi_flag_offset] = 0x00;
		}

		buffer += s->data_block_quadlets;

		if (--p->midi_db_count < 0)
			p->midi_db_count = p->midi_db_interval;
	}
}

static void read_midi_messages(struct amdtp_stream *s, __be32 *buffer,
			       unsigned int data_blocks)
{
	struct amdtp_motu *p = s->protocol;
	struct snd_rawmidi_substream *midi;
	u8 *b;
	int i;

	for (i = 0; i < data_blocks; i++) {
		b = (u8 *)buffer;
		midi = READ_ONCE(p->midi);

		if (midi && (b[p->midi_flag_offset] & 0x01))
			snd_rawmidi_receive(midi, b + p->midi_byte_offset, 1);

		buffer += s->data_block_quadlets;
	}
}

/* For tracepoints. */
static void copy_sph(u32 *frames, __be32 *buffer, unsigned int data_blocks,
		     unsigned int data_block_quadlets)
{
	unsigned int i;

	for (i = 0; i < data_blocks; ++i) {
		*frames = be32_to_cpu(*buffer);
		buffer += data_block_quadlets;
		frames++;
	}
}

static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
				__be32 *buffer, unsigned int data_blocks,
				unsigned int *syt)
{
	struct amdtp_motu *p = s->protocol;
	struct snd_pcm_substream *pcm;

	trace_in_data_block_sph(s, data_blocks, buffer);

	if (p->midi_ports)
		read_midi_messages(s, buffer, data_blocks);

	pcm = ACCESS_ONCE(s->pcm);
	if (data_blocks > 0 && pcm)
		read_pcm_s32(s, pcm->runtime, buffer, data_blocks);

	return data_blocks;
}

static inline void compute_next_elapse_from_start(struct amdtp_motu *p)
{
	p->next_accumulated += p->remainder_ticks_per_event;
	if (p->next_accumulated >= 441) {
		p->next_accumulated -= 441;
		p->next_ticks++;
	}

	p->next_ticks += p->quotient_ticks_per_event;
	if (p->next_ticks >= 3072) {
		p->next_ticks -= 3072;
		p->next_cycles++;
	}

	if (p->next_cycles >= 8000) {
		p->next_cycles -= 8000;
		p->next_seconds++;
	}

	if (p->next_seconds >= 128)
		p->next_seconds -= 128;
}

static void write_sph(struct amdtp_stream *s, __be32 *buffer,
		      unsigned int data_blocks)
{
	struct amdtp_motu *p = s->protocol;
	unsigned int next_cycles;
	unsigned int i;
	u32 sph;

	for (i = 0; i < data_blocks; i++) {
		next_cycles = (s->start_cycle + p->next_cycles) % 8000;
		sph = ((next_cycles << 12) | p->next_ticks) & 0x01ffffff;
		*buffer = cpu_to_be32(sph);

		compute_next_elapse_from_start(p);

		buffer += s->data_block_quadlets;
	}
}

static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
				__be32 *buffer, unsigned int data_blocks,
				unsigned int *syt)
{
	struct amdtp_motu *p = (struct amdtp_motu *)s->protocol;
	struct snd_pcm_substream *pcm;

	/* Not used. */
	*syt = 0xffff;

	/* TODO: how to interact control messages between userspace? */

	if (p->midi_ports)
		write_midi_messages(s, buffer, data_blocks);

	pcm = ACCESS_ONCE(s->pcm);
	if (pcm)
		write_pcm_s32(s, pcm->runtime, buffer, data_blocks);
	else
		write_pcm_silence(s, buffer, data_blocks);

	write_sph(s, buffer, data_blocks);

	trace_out_data_block_sph(s, data_blocks, buffer);

	return data_blocks;
}

int amdtp_motu_init(struct amdtp_stream *s, struct fw_unit *unit,
		    enum amdtp_stream_direction dir,
		    const struct snd_motu_protocol *const protocol)
{
	amdtp_stream_process_data_blocks_t process_data_blocks;
	int fmt = CIP_FMT_MOTU;
	int flags = CIP_BLOCKING;
	int err;

	if (dir == AMDTP_IN_STREAM) {
		process_data_blocks = process_tx_data_blocks;

		/*
		 * Units of version 3 transmits packets with invalid CIP header
		 * against IEC 61883-1.
		 */
		if (protocol == &snd_motu_protocol_v3) {
			flags |= CIP_WRONG_DBS |
				 CIP_SKIP_DBC_ZERO_CHECK |
				 CIP_HEADER_WITHOUT_EOH;
			fmt = CIP_FMT_MOTU_TX_V3;
		}
	} else {
		process_data_blocks = process_rx_data_blocks;
		flags |= CIP_DBC_IS_END_EVENT;
	}

	err = amdtp_stream_init(s, unit, dir, flags, fmt, process_data_blocks,
				sizeof(struct amdtp_motu));
	if (err < 0)
		return err;

	s->sph = 1;
	s->fdf = MOTU_FDF_AM824;

	return 0;
}
Commit	Line	Data
4641c939 TS	1	/*
	2	* amdtp-motu.c - a part of driver for MOTU FireWire series
	3	*
	4	* Copyright (c) 2015-2017 Takashi Sakamoto <o-takashi@sakamocchi.jp>
	5	*
	6	* Licensed under the terms of the GNU General Public License, version 2.
	7	*/
	8
	9	#include <linux/slab.h>
	10	#include <sound/pcm.h>
	11	#include "motu.h"
	12
17909c1b TS	13	#define CREATE_TRACE_POINTS
	14	#include "amdtp-motu-trace.h"
	15
4641c939	16	#define CIP_FMT_MOTU 0x02
5992e300	17	#define CIP_FMT_MOTU_TX_V3 0x22
4641c939 TS	18	#define MOTU_FDF_AM824 0x22
4641c939 TS	19
9e796e7d TS	20	/*
	21	* Nominally 3125 bytes/second, but the MIDI port's clock might be
	22	* 1% too slow, and the bus clock 100 ppm too fast.
	23	*/
	24	#define MIDI_BYTES_PER_SECOND 3093
	25
4641c939 TS	26	struct amdtp_motu {
	27	/* For timestamp processing. */
	28	unsigned int quotient_ticks_per_event;
	29	unsigned int remainder_ticks_per_event;
	30	unsigned int next_ticks;
	31	unsigned int next_accumulated;
	32	unsigned int next_cycles;
	33	unsigned int next_seconds;
	34
	35	unsigned int pcm_chunks;
	36	unsigned int pcm_byte_offset;
9e796e7d TS	37
	38	struct snd_rawmidi_substream *midi;
	39	unsigned int midi_ports;
	40	unsigned int midi_flag_offset;
	41	unsigned int midi_byte_offset;
	42
	43	int midi_db_count;
	44	unsigned int midi_db_interval;
4641c939 TS	45	};
	46
	47	int amdtp_motu_set_parameters(struct amdtp_stream *s, unsigned int rate,
9e796e7d	48	unsigned int midi_ports,
4641c939 TS	49	struct snd_motu_packet_format *formats)
	50	{
	51	static const struct {
	52	unsigned int quotient_ticks_per_event;
	53	unsigned int remainder_ticks_per_event;
	54	} params[] = {
	55	[CIP_SFC_44100] = { 557, 123 },
	56	[CIP_SFC_48000] = { 512, 0 },
	57	[CIP_SFC_88200] = { 278, 282 },
	58	[CIP_SFC_96000] = { 256, 0 },
	59	[CIP_SFC_176400] = { 139, 141 },
	60	[CIP_SFC_192000] = { 128, 0 },
	61	};
	62	struct amdtp_motu *p = s->protocol;
	63	unsigned int pcm_chunks, data_chunks, data_block_quadlets;
	64	unsigned int delay;
	65	unsigned int mode;
	66	int i, err;
	67
	68	if (amdtp_stream_running(s))
	69	return -EBUSY;
	70
	71	for (i = 0; i < ARRAY_SIZE(snd_motu_clock_rates); ++i) {
	72	if (snd_motu_clock_rates[i] == rate) {
	73	mode = i >> 1;
	74	break;
	75	}
	76	}
	77	if (i == ARRAY_SIZE(snd_motu_clock_rates))
	78	return -EINVAL;
	79
	80	pcm_chunks = formats->fixed_part_pcm_chunks[mode] +
	81	formats->differed_part_pcm_chunks[mode];
	82	data_chunks = formats->msg_chunks + pcm_chunks;
	83
	84	/*
	85	* Each data block includes SPH in its head. Data chunks follow with
	86	* 3 byte alignment. Padding follows with zero to conform to quadlet
	87	* alignment.
	88	*/
	89	data_block_quadlets = 1 + DIV_ROUND_UP(data_chunks * 3, 4);
	90
	91	err = amdtp_stream_set_parameters(s, rate, data_block_quadlets);
	92	if (err < 0)
	93	return err;
	94
	95	p->pcm_chunks = pcm_chunks;
	96	p->pcm_byte_offset = formats->pcm_byte_offset;
	97
9e796e7d TS	98	p->midi_ports = midi_ports;
	99	p->midi_flag_offset = formats->midi_flag_offset;
	100	p->midi_byte_offset = formats->midi_byte_offset;
	101
	102	p->midi_db_count = 0;
	103	p->midi_db_interval = rate / MIDI_BYTES_PER_SECOND;
	104
4641c939 TS	105	/* IEEE 1394 bus requires. */
	106	delay = 0x2e00;
	107
	108	/* For no-data or empty packets to adjust PCM sampling frequency. */
	109	delay += 8000 * 3072 * s->syt_interval / rate;
	110
	111	p->next_seconds = 0;
	112	p->next_cycles = delay / 3072;
	113	p->quotient_ticks_per_event = params[s->sfc].quotient_ticks_per_event;
	114	p->remainder_ticks_per_event = params[s->sfc].remainder_ticks_per_event;
	115	p->next_ticks = delay % 3072;
	116	p->next_accumulated = 0;
	117
	118	return 0;
	119	}
	120
	121	static void read_pcm_s32(struct amdtp_stream *s,
	122	struct snd_pcm_runtime *runtime,
	123	__be32 *buffer, unsigned int data_blocks)
	124	{
	125	struct amdtp_motu *p = s->protocol;
	126	unsigned int channels, remaining_frames, i, c;
	127	u8 *byte;
	128	u32 *dst;
	129
	130	channels = p->pcm_chunks;
	131	dst = (void *)runtime->dma_area +
	132	frames_to_bytes(runtime, s->pcm_buffer_pointer);
	133	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
	134
	135	for (i = 0; i < data_blocks; ++i) {
	136	byte = (u8 *)buffer + p->pcm_byte_offset;
	137
	138	for (c = 0; c < channels; ++c) {
	139	*dst = (byte[0] << 24) \| (byte[1] << 16) \| byte[2];
	140	byte += 3;
	141	dst++;
	142	}
	143	buffer += s->data_block_quadlets;
	144	if (--remaining_frames == 0)
	145	dst = (void *)runtime->dma_area;
	146	}
	147	}
	148
	149	static void write_pcm_s32(struct amdtp_stream *s,
	150	struct snd_pcm_runtime *runtime,
	151	__be32 *buffer, unsigned int data_blocks)
	152	{
	153	struct amdtp_motu *p = s->protocol;
	154	unsigned int channels, remaining_frames, i, c;
	155	u8 *byte;
	156	const u32 *src;
	157
	158	channels = p->pcm_chunks;
	159	src = (void *)runtime->dma_area +
	160	frames_to_bytes(runtime, s->pcm_buffer_pointer);
	161	remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
	162
	163	for (i = 0; i < data_blocks; ++i) {
	164	byte = (u8 *)buffer + p->pcm_byte_offset;
	165
	166	for (c = 0; c < channels; ++c) {
	167	byte[0] = (*src >> 24) & 0xff;
	168	byte[1] = (*src >> 16) & 0xff;
169	byte[2] = (*src >> 8) & 0xff;
170	byte += 3;
171	src++;
172	}
173
174	buffer += s->data_block_quadlets;
175	if (--remaining_frames == 0)
176	src = (void *)runtime->dma_area;
177	}
178	}
179
180	static void write_pcm_silence(struct amdtp_stream s, __be32 buffer,
181	unsigned int data_blocks)
182	{
183	struct amdtp_motu *p = s->protocol;
184	unsigned int channels, i, c;
185	u8 *byte;
186
187	channels = p->pcm_chunks;
188
189	for (i = 0; i < data_blocks; ++i) {
190	byte = (u8 *)buffer + p->pcm_byte_offset;
191
192	for (c = 0; c < channels; ++c) {
193	byte[0] = 0;
194	byte[1] = 0;
195	byte[2] = 0;
196	byte += 3;
197	}
198
199	buffer += s->data_block_quadlets;
200	}
201	}
202
203	int amdtp_motu_add_pcm_hw_constraints(struct amdtp_stream *s,
204	struct snd_pcm_runtime *runtime)
205	{
206	int err;
207
208	/* TODO: how to set an constraint for exactly 24bit PCM sample? */
209	err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
210	if (err < 0)
211	return err;
212
213	return amdtp_stream_add_pcm_hw_constraints(s, runtime);
214	}
215
9e796e7d TS	216	void amdtp_motu_midi_trigger(struct amdtp_stream *s, unsigned int port,
	217	struct snd_rawmidi_substream *midi)
	218	{
	219	struct amdtp_motu *p = s->protocol;
	220
	221	if (port < p->midi_ports)
	222	WRITE_ONCE(p->midi, midi);
	223	}
	224
	225	static void write_midi_messages(struct amdtp_stream s, __be32 buffer,
	226	unsigned int data_blocks)
	227	{
	228	struct amdtp_motu *p = s->protocol;
	229	struct snd_rawmidi_substream *midi = READ_ONCE(p->midi);
	230	u8 *b;
	231	int i;
	232
	233	for (i = 0; i < data_blocks; i++) {
	234	b = (u8 *)buffer;
	235
	236	if (midi && p->midi_db_count == 0 &&
	237	snd_rawmidi_transmit(midi, b + p->midi_byte_offset, 1) == 1) {
	238	b[p->midi_flag_offset] = 0x01;
	239	} else {
	240	b[p->midi_byte_offset] = 0x00;
	241	b[p->midi_flag_offset] = 0x00;
	242	}
	243
	244	buffer += s->data_block_quadlets;
	245
	246	if (--p->midi_db_count < 0)
	247	p->midi_db_count = p->midi_db_interval;
	248	}
	249	}
	250
	251	static void read_midi_messages(struct amdtp_stream s, __be32 buffer,
	252	unsigned int data_blocks)
	253	{
	254	struct amdtp_motu *p = s->protocol;
	255	struct snd_rawmidi_substream *midi;
	256	u8 *b;
	257	int i;
	258
	259	for (i = 0; i < data_blocks; i++) {
	260	b = (u8 *)buffer;
	261	midi = READ_ONCE(p->midi);
	262
	263	if (midi && (b[p->midi_flag_offset] & 0x01))
	264	snd_rawmidi_receive(midi, b + p->midi_byte_offset, 1);
	265
	266	buffer += s->data_block_quadlets;
	267	}
	268	}
	269
17909c1b TS	270	/* For tracepoints. */
	271	static void copy_sph(u32 frames, __be32 buffer, unsigned int data_blocks,
	272	unsigned int data_block_quadlets)
	273	{
	274	unsigned int i;
	275
	276	for (i = 0; i < data_blocks; ++i) {
	277	frames = be32_to_cpu(buffer);
	278	buffer += data_block_quadlets;
	279	frames++;
	280	}
	281	}
	282
4641c939 TS	283	static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
	284	__be32 *buffer, unsigned int data_blocks,
	285	unsigned int *syt)
	286	{
9e796e7d	287	struct amdtp_motu *p = s->protocol;
4641c939 TS	288	struct snd_pcm_substream *pcm;
4641c939 TS	289
17909c1b TS	290	trace_in_data_block_sph(s, data_blocks, buffer);
17909c1b TS	291
9e796e7d TS	292	if (p->midi_ports)
	293	read_midi_messages(s, buffer, data_blocks);
	294
4641c939 TS	295	pcm = ACCESS_ONCE(s->pcm);
	296	if (data_blocks > 0 && pcm)
	297	read_pcm_s32(s, pcm->runtime, buffer, data_blocks);
	298
	299	return data_blocks;
	300	}
	301
	302	static inline void compute_next_elapse_from_start(struct amdtp_motu *p)
	303	{
	304	p->next_accumulated += p->remainder_ticks_per_event;
	305	if (p->next_accumulated >= 441) {
	306	p->next_accumulated -= 441;
	307	p->next_ticks++;
	308	}
	309
	310	p->next_ticks += p->quotient_ticks_per_event;
	311	if (p->next_ticks >= 3072) {
	312	p->next_ticks -= 3072;
	313	p->next_cycles++;
	314	}
	315
	316	if (p->next_cycles >= 8000) {
	317	p->next_cycles -= 8000;
	318	p->next_seconds++;
	319	}
	320
	321	if (p->next_seconds >= 128)
	322	p->next_seconds -= 128;
	323	}
	324
	325	static void write_sph(struct amdtp_stream s, __be32 buffer,
	326	unsigned int data_blocks)
	327	{
	328	struct amdtp_motu *p = s->protocol;
	329	unsigned int next_cycles;
	330	unsigned int i;
	331	u32 sph;
	332
	333	for (i = 0; i < data_blocks; i++) {
	334	next_cycles = (s->start_cycle + p->next_cycles) % 8000;
	335	sph = ((next_cycles << 12) \| p->next_ticks) & 0x01ffffff;
	336	*buffer = cpu_to_be32(sph);
	337
	338	compute_next_elapse_from_start(p);
	339
	340	buffer += s->data_block_quadlets;
	341	}
	342	}
	343
	344	static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
	345	__be32 *buffer, unsigned int data_blocks,
	346	unsigned int *syt)
	347	{
9e796e7d	348	struct amdtp_motu p = (struct amdtp_motu )s->protocol;
4641c939 TS	349	struct snd_pcm_substream *pcm;
	350
	351	/* Not used. */
	352	*syt = 0xffff;
	353
	354	/* TODO: how to interact control messages between userspace? */
	355
9e796e7d TS	356	if (p->midi_ports)
	357	write_midi_messages(s, buffer, data_blocks);
	358
4641c939 TS	359	pcm = ACCESS_ONCE(s->pcm);
	360	if (pcm)
	361	write_pcm_s32(s, pcm->runtime, buffer, data_blocks);
	362	else
	363	write_pcm_silence(s, buffer, data_blocks);
	364
	365	write_sph(s, buffer, data_blocks);
	366
17909c1b TS	367	trace_out_data_block_sph(s, data_blocks, buffer);
17909c1b TS	368
4641c939 TS	369	return data_blocks;
	370	}
	371
	372	int amdtp_motu_init(struct amdtp_stream s, struct fw_unit unit,
	373	enum amdtp_stream_direction dir,
	374	const struct snd_motu_protocol *const protocol)
	375	{
	376	amdtp_stream_process_data_blocks_t process_data_blocks;
	377	int fmt = CIP_FMT_MOTU;
	378	int flags = CIP_BLOCKING;
	379	int err;
	380
	381	if (dir == AMDTP_IN_STREAM) {
	382	process_data_blocks = process_tx_data_blocks;
5992e300 TS	383
	384	/*
	385	* Units of version 3 transmits packets with invalid CIP header
	386	* against IEC 61883-1.
	387	*/
	388	if (protocol == &snd_motu_protocol_v3) {
	389	flags \|= CIP_WRONG_DBS \|
	390	CIP_SKIP_DBC_ZERO_CHECK \|
	391	CIP_HEADER_WITHOUT_EOH;
	392	fmt = CIP_FMT_MOTU_TX_V3;
	393	}
4641c939 TS	394	} else {
	395	process_data_blocks = process_rx_data_blocks;
	396	flags \|= CIP_DBC_IS_END_EVENT;
	397	}
	398
	399	err = amdtp_stream_init(s, unit, dir, flags, fmt, process_data_blocks,
	400	sizeof(struct amdtp_motu));
	401	if (err < 0)
	402	return err;
	403
	404	s->sph = 1;
	405	s->fdf = MOTU_FDF_AM824;
	406
	407	return 0;
	408	}