amdtp-stream.c 24.6 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14
/*
 * Audio and Music Data Transmission Protocol (IEC 61883-6) streams
 * with Common Isochronous Packet (IEC 61883-1) headers
 *
 * Copyright (c) Clemens Ladisch <clemens@ladisch.de>
 * Licensed under the terms of the GNU General Public License, version 2.
 */

#include <linux/device.h>
#include <linux/err.h>
#include <linux/firewire.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <sound/pcm.h>
15
#include <sound/pcm_params.h>
16
#include "amdtp-stream.h"
17 18 19 20 21

#define TICKS_PER_CYCLE		3072
#define CYCLES_PER_SECOND	8000
#define TICKS_PER_SECOND	(TICKS_PER_CYCLE * CYCLES_PER_SECOND)

22 23 24 25
/* Always support Linux tracing subsystem. */
#define CREATE_TRACE_POINTS
#include "amdtp-stream-trace.h"

26
#define TRANSFER_DELAY_TICKS	0x2e00 /* 479.17 microseconds */
27

28 29
/* isochronous header parameters */
#define ISO_DATA_LENGTH_SHIFT	16
30 31
#define TAG_CIP			1

32
/* common isochronous packet header parameters */
33 34
#define CIP_EOH_SHIFT		31
#define CIP_EOH			(1u << CIP_EOH_SHIFT)
35
#define CIP_EOH_MASK		0x80000000
36 37 38 39
#define CIP_SID_SHIFT		24
#define CIP_SID_MASK		0x3f000000
#define CIP_DBS_MASK		0x00ff0000
#define CIP_DBS_SHIFT		16
40 41
#define CIP_SPH_MASK		0x00000400
#define CIP_SPH_SHIFT		10
42 43
#define CIP_DBC_MASK		0x000000ff
#define CIP_FMT_SHIFT		24
44
#define CIP_FMT_MASK		0x3f000000
45 46
#define CIP_FDF_MASK		0x00ff0000
#define CIP_FDF_SHIFT		16
47 48 49
#define CIP_SYT_MASK		0x0000ffff
#define CIP_SYT_NO_INFO		0xffff

50
/* Audio and Music transfer protocol specific parameters */
51
#define CIP_FMT_AM		0x10
52
#define AMDTP_FDF_NO_DATA	0xff
53 54 55 56 57

/* TODO: make these configurable */
#define INTERRUPT_INTERVAL	16
#define QUEUE_LENGTH		48

58
#define IN_PACKET_HEADER_SIZE	4
59 60
#define OUT_PACKET_HEADER_SIZE	0

61 62
static void pcm_period_tasklet(unsigned long data);

63
/**
64 65
 * amdtp_stream_init - initialize an AMDTP stream structure
 * @s: the AMDTP stream to initialize
66
 * @unit: the target of the stream
67
 * @dir: the direction of stream
68
 * @flags: the packet transmission method to use
69
 * @fmt: the value of fmt field in CIP header
70 71
 * @process_data_blocks: callback handler to process data blocks
 * @protocol_size: the size to allocate newly for protocol
72
 */
73
int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
74
		      enum amdtp_stream_direction dir, enum cip_flags flags,
75 76 77
		      unsigned int fmt,
		      amdtp_stream_process_data_blocks_t process_data_blocks,
		      unsigned int protocol_size)
78
{
79 80 81 82 83 84 85
	if (process_data_blocks == NULL)
		return -EINVAL;

	s->protocol = kzalloc(protocol_size, GFP_KERNEL);
	if (!s->protocol)
		return -ENOMEM;

86
	s->unit = unit;
87
	s->direction = dir;
88 89 90
	s->flags = flags;
	s->context = ERR_PTR(-1);
	mutex_init(&s->mutex);
91
	tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s);
92
	s->packet_index = 0;
93

94 95 96
	init_waitqueue_head(&s->callback_wait);
	s->callbacked = false;

97
	s->fmt = fmt;
98
	s->process_data_blocks = process_data_blocks;
99

100 101
	return 0;
}
102
EXPORT_SYMBOL(amdtp_stream_init);
103 104

/**
105 106
 * amdtp_stream_destroy - free stream resources
 * @s: the AMDTP stream to destroy
107
 */
108
void amdtp_stream_destroy(struct amdtp_stream *s)
109
{
110 111 112 113
	/* Not initialized. */
	if (s->protocol == NULL)
		return;

114
	WARN_ON(amdtp_stream_running(s));
115
	kfree(s->protocol);
116 117
	mutex_destroy(&s->mutex);
}
118
EXPORT_SYMBOL(amdtp_stream_destroy);
119

120
const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = {
121 122 123 124 125 126 127 128 129 130
	[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);

131
const unsigned int amdtp_rate_table[CIP_SFC_COUNT] = {
132 133 134 135 136 137 138 139 140 141
	[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,
};
EXPORT_SYMBOL(amdtp_rate_table);

142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175
/**
 * amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream
 * @s:		the AMDTP stream, which must be initialized.
 * @runtime:	the PCM substream runtime
 */
int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
					struct snd_pcm_runtime *runtime)
{
	int err;

	/*
	 * Currently firewire-lib processes 16 packets in one software
	 * interrupt callback. This equals to 2msec but actually the
	 * interval of the interrupts has a jitter.
	 * Additionally, even if adding a constraint to fit period size to
	 * 2msec, actual calculated frames per period doesn't equal to 2msec,
	 * depending on sampling rate.
	 * Anyway, the interval to call snd_pcm_period_elapsed() cannot 2msec.
	 * Here let us use 5msec for safe period interrupt.
	 */
	err = snd_pcm_hw_constraint_minmax(runtime,
					   SNDRV_PCM_HW_PARAM_PERIOD_TIME,
					   5000, UINT_MAX);
	if (err < 0)
		goto end;

	/* Non-Blocking stream has no more constraints */
	if (!(s->flags & CIP_BLOCKING))
		goto end;

	/*
	 * One AMDTP packet can include some frames. In blocking mode, the
	 * number equals to SYT_INTERVAL. So the number is 8, 16 or 32,
	 * depending on its sampling rate. For accurate period interrupt, it's
176
	 * preferrable to align period/buffer sizes to current SYT_INTERVAL.
177
	 *
178 179
	 * TODO: These constraints can be improved with proper rules.
	 * Currently apply LCM of SYT_INTERVALs.
180 181 182 183 184 185 186 187 188 189 190 191
	 */
	err = snd_pcm_hw_constraint_step(runtime, 0,
					 SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 32);
	if (err < 0)
		goto end;
	err = snd_pcm_hw_constraint_step(runtime, 0,
					 SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 32);
end:
	return err;
}
EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints);

192
/**
193 194
 * amdtp_stream_set_parameters - set stream parameters
 * @s: the AMDTP stream to configure
195
 * @rate: the sample rate
196
 * @data_block_quadlets: the size of a data block in quadlet unit
197
 *
198
 * The parameters must be set before the stream is started, and must not be
199 200
 * changed while the stream is running.
 */
201 202
int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate,
				unsigned int data_block_quadlets)
203
{
204
	unsigned int sfc;
205

206
	for (sfc = 0; sfc < ARRAY_SIZE(amdtp_rate_table); ++sfc) {
207
		if (amdtp_rate_table[sfc] == rate)
208 209 210 211
			break;
	}
	if (sfc == ARRAY_SIZE(amdtp_rate_table))
		return -EINVAL;
212 213

	s->sfc = sfc;
214
	s->data_block_quadlets = data_block_quadlets;
215
	s->syt_interval = amdtp_syt_intervals[sfc];
216 217 218 219 220 221

	/* default buffering in the device */
	s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
	if (s->flags & CIP_BLOCKING)
		/* additional buffering needed to adjust for no-data packets */
		s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate;
222

223
	return 0;
224
}
225
EXPORT_SYMBOL(amdtp_stream_set_parameters);
226 227

/**
228 229
 * amdtp_stream_get_max_payload - get the stream's packet size
 * @s: the AMDTP stream
230 231
 *
 * This function must not be called before the stream has been configured
232
 * with amdtp_stream_set_parameters().
233
 */
234
unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s)
235
{
236 237 238 239 240 241
	unsigned int multiplier = 1;

	if (s->flags & CIP_JUMBO_PAYLOAD)
		multiplier = 5;

	return 8 + s->syt_interval * s->data_block_quadlets * 4 * multiplier;
242
}
243
EXPORT_SYMBOL(amdtp_stream_get_max_payload);
244

245
/**
246 247
 * amdtp_stream_pcm_prepare - prepare PCM device for running
 * @s: the AMDTP stream
248 249 250
 *
 * This function should be called from the PCM device's .prepare callback.
 */
251
void amdtp_stream_pcm_prepare(struct amdtp_stream *s)
252 253 254 255 256
{
	tasklet_kill(&s->period_tasklet);
	s->pcm_buffer_pointer = 0;
	s->pcm_period_pointer = 0;
}
257
EXPORT_SYMBOL(amdtp_stream_pcm_prepare);
258

259 260
static unsigned int calculate_data_blocks(struct amdtp_stream *s,
					  unsigned int syt)
261 262 263
{
	unsigned int phase, data_blocks;

264 265 266 267 268 269 270 271
	/* Blocking mode. */
	if (s->flags & CIP_BLOCKING) {
		/* This module generate empty packet for 'no data'. */
		if (syt == CIP_SYT_NO_INFO)
			data_blocks = 0;
		else
			data_blocks = s->syt_interval;
	/* Non-blocking mode. */
272
	} else {
273 274 275 276 277
		if (!cip_sfc_is_base_44100(s->sfc)) {
			/* Sample_rate / 8000 is an integer, and precomputed. */
			data_blocks = s->data_block_state;
		} else {
			phase = s->data_block_state;
278 279 280 281 282 283 284 285 286

		/*
		 * This calculates the number of data blocks per packet so that
		 * 1) the overall rate is correct and exactly synchronized to
		 *    the bus clock, and
		 * 2) packets with a rounded-up number of blocks occur as early
		 *    as possible in the sequence (to prevent underruns of the
		 *    device's buffer).
		 */
287 288 289 290 291 292 293 294 295 296 297
			if (s->sfc == CIP_SFC_44100)
				/* 6 6 5 6 5 6 5 ... */
				data_blocks = 5 + ((phase & 1) ^
						   (phase == 0 || phase >= 40));
			else
				/* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
				data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
			if (++phase >= (80 >> (s->sfc >> 1)))
				phase = 0;
			s->data_block_state = phase;
		}
298 299 300 301 302
	}

	return data_blocks;
}

303
static unsigned int calculate_syt(struct amdtp_stream *s,
304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334
				  unsigned int cycle)
{
	unsigned int syt_offset, phase, index, syt;

	if (s->last_syt_offset < TICKS_PER_CYCLE) {
		if (!cip_sfc_is_base_44100(s->sfc))
			syt_offset = s->last_syt_offset + s->syt_offset_state;
		else {
		/*
		 * The time, in ticks, of the n'th SYT_INTERVAL sample is:
		 *   n * SYT_INTERVAL * 24576000 / sample_rate
		 * Modulo TICKS_PER_CYCLE, the difference between successive
		 * elements is about 1386.23.  Rounding the results of this
		 * formula to the SYT precision results in a sequence of
		 * differences that begins with:
		 *   1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
		 * This code generates _exactly_ the same sequence.
		 */
			phase = s->syt_offset_state;
			index = phase % 13;
			syt_offset = s->last_syt_offset;
			syt_offset += 1386 + ((index && !(index & 3)) ||
					      phase == 146);
			if (++phase >= 147)
				phase = 0;
			s->syt_offset_state = phase;
		}
	} else
		syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
	s->last_syt_offset = syt_offset;

335
	if (syt_offset < TICKS_PER_CYCLE) {
336
		syt_offset += s->transfer_delay;
337 338
		syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
		syt += syt_offset % TICKS_PER_CYCLE;
339

340
		return syt & CIP_SYT_MASK;
341
	} else {
342
		return CIP_SYT_NO_INFO;
343
	}
344 345
}

346 347 348
static void update_pcm_pointers(struct amdtp_stream *s,
				struct snd_pcm_substream *pcm,
				unsigned int frames)
349 350 351
{
	unsigned int ptr;

352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372
	ptr = s->pcm_buffer_pointer + frames;
	if (ptr >= pcm->runtime->buffer_size)
		ptr -= pcm->runtime->buffer_size;
	ACCESS_ONCE(s->pcm_buffer_pointer) = ptr;

	s->pcm_period_pointer += frames;
	if (s->pcm_period_pointer >= pcm->runtime->period_size) {
		s->pcm_period_pointer -= pcm->runtime->period_size;
		tasklet_hi_schedule(&s->period_tasklet);
	}
}

static void pcm_period_tasklet(unsigned long data)
{
	struct amdtp_stream *s = (void *)data;
	struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm);

	if (pcm)
		snd_pcm_period_elapsed(pcm);
}

373 374
static int queue_packet(struct amdtp_stream *s, unsigned int header_length,
			unsigned int payload_length)
375 376
{
	struct fw_iso_packet p = {0};
377 378 379 380
	int err = 0;

	if (IS_ERR(s->context))
		goto end;
381 382 383 384

	p.interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL);
	p.tag = TAG_CIP;
	p.header_length = header_length;
385 386 387 388
	if (payload_length > 0)
		p.payload_length = payload_length;
	else
		p.skip = true;
389 390 391 392 393 394 395 396 397 398 399 400 401 402
	err = fw_iso_context_queue(s->context, &p, &s->buffer.iso_buffer,
				   s->buffer.packets[s->packet_index].offset);
	if (err < 0) {
		dev_err(&s->unit->device, "queueing error: %d\n", err);
		goto end;
	}

	if (++s->packet_index >= QUEUE_LENGTH)
		s->packet_index = 0;
end:
	return err;
}

static inline int queue_out_packet(struct amdtp_stream *s,
403
				   unsigned int payload_length)
404
{
405
	return queue_packet(s, OUT_PACKET_HEADER_SIZE, payload_length);
406 407
}

408 409 410
static inline int queue_in_packet(struct amdtp_stream *s)
{
	return queue_packet(s, IN_PACKET_HEADER_SIZE,
411
			    amdtp_stream_get_max_payload(s));
412 413
}

414 415
static int handle_out_packet(struct amdtp_stream *s,
			     unsigned int payload_length, unsigned int cycle,
416
			     unsigned int index)
417 418
{
	__be32 *buffer;
419 420
	unsigned int syt;
	unsigned int data_blocks;
421
	unsigned int pcm_frames;
422 423
	struct snd_pcm_substream *pcm;

424
	buffer = s->buffer.packets[s->packet_index].buffer;
425 426
	syt = calculate_syt(s, cycle);
	data_blocks = calculate_data_blocks(s, syt);
427
	pcm_frames = s->process_data_blocks(s, buffer + 2, data_blocks, &syt);
428

429 430 431 432
	if (s->flags & CIP_DBC_IS_END_EVENT)
		s->data_block_counter =
				(s->data_block_counter + data_blocks) & 0xff;

433
	buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) |
434
				(s->data_block_quadlets << CIP_DBS_SHIFT) |
435
				((s->sph << CIP_SPH_SHIFT) & CIP_SPH_MASK) |
436
				s->data_block_counter);
437 438 439 440
	buffer[1] = cpu_to_be32(CIP_EOH |
				((s->fmt << CIP_FMT_SHIFT) & CIP_FMT_MASK) |
				((s->fdf << CIP_FDF_SHIFT) & CIP_FDF_MASK) |
				(syt & CIP_SYT_MASK));
441

442 443 444
	if (!(s->flags & CIP_DBC_IS_END_EVENT))
		s->data_block_counter =
				(s->data_block_counter + data_blocks) & 0xff;
445
	payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
446

447
	trace_out_packet(s, cycle, buffer, payload_length, index);
448

449
	if (queue_out_packet(s, payload_length) < 0)
450
		return -EIO;
451

452 453 454
	pcm = ACCESS_ONCE(s->pcm);
	if (pcm && pcm_frames > 0)
		update_pcm_pointers(s, pcm, pcm_frames);
455 456 457

	/* No need to return the number of handled data blocks. */
	return 0;
458 459
}

460
static int handle_in_packet(struct amdtp_stream *s,
461
			    unsigned int payload_length, unsigned int cycle,
462
			    unsigned int index)
463
{
464
	__be32 *buffer;
465
	u32 cip_header[2];
466
	unsigned int sph, fmt, fdf, syt;
467
	unsigned int data_block_quadlets, data_block_counter, dbc_interval;
468
	unsigned int data_blocks;
469 470
	struct snd_pcm_substream *pcm;
	unsigned int pcm_frames;
471
	bool lost;
472

473
	buffer = s->buffer.packets[s->packet_index].buffer;
474 475 476
	cip_header[0] = be32_to_cpu(buffer[0]);
	cip_header[1] = be32_to_cpu(buffer[1]);

477
	trace_in_packet(s, cycle, cip_header, payload_length, index);
478

479 480
	/*
	 * This module supports 'Two-quadlet CIP header with SYT field'.
481
	 * For convenience, also check FMT field is AM824 or not.
482
	 */
483 484 485
	if ((((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) ||
	     ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH)) &&
	    (!(s->flags & CIP_HEADER_WITHOUT_EOH))) {
486 487 488
		dev_info_ratelimited(&s->unit->device,
				"Invalid CIP header for AMDTP: %08X:%08X\n",
				cip_header[0], cip_header[1]);
489
		data_blocks = 0;
490
		pcm_frames = 0;
491 492 493
		goto end;
	}

494
	/* Check valid protocol or not. */
495
	sph = (cip_header[0] & CIP_SPH_MASK) >> CIP_SPH_SHIFT;
496
	fmt = (cip_header[1] & CIP_FMT_MASK) >> CIP_FMT_SHIFT;
497
	if (sph != s->sph || fmt != s->fmt) {
498 499 500
		dev_info_ratelimited(&s->unit->device,
				     "Detect unexpected protocol: %08x %08x\n",
				     cip_header[0], cip_header[1]);
501
		data_blocks = 0;
502 503
		pcm_frames = 0;
		goto end;
504 505
	}

506
	/* Calculate data blocks */
507
	fdf = (cip_header[1] & CIP_FDF_MASK) >> CIP_FDF_SHIFT;
508
	if (payload_length < 12 ||
509
	    (fmt == CIP_FMT_AM && fdf == AMDTP_FDF_NO_DATA)) {
510
		data_blocks = 0;
511 512
	} else {
		data_block_quadlets =
513
			(cip_header[0] & CIP_DBS_MASK) >> CIP_DBS_SHIFT;
514 515
		/* avoid division by zero */
		if (data_block_quadlets == 0) {
516
			dev_err(&s->unit->device,
517 518
				"Detect invalid value in dbs field: %08X\n",
				cip_header[0]);
519
			return -EPROTO;
520
		}
521 522
		if (s->flags & CIP_WRONG_DBS)
			data_block_quadlets = s->data_block_quadlets;
523

524 525
		data_blocks = (payload_length / 4 - 2) /
							data_block_quadlets;
526 527 528
	}

	/* Check data block counter continuity */
529
	data_block_counter = cip_header[0] & CIP_DBC_MASK;
530
	if (data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) &&
531 532 533
	    s->data_block_counter != UINT_MAX)
		data_block_counter = s->data_block_counter;

534 535 536
	if (((s->flags & CIP_SKIP_DBC_ZERO_CHECK) &&
	     data_block_counter == s->tx_first_dbc) ||
	    s->data_block_counter == UINT_MAX) {
537 538
		lost = false;
	} else if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
539
		lost = data_block_counter != s->data_block_counter;
540
	} else {
541
		if (data_blocks > 0 && s->tx_dbc_interval > 0)
542 543
			dbc_interval = s->tx_dbc_interval;
		else
544
			dbc_interval = data_blocks;
545

546
		lost = data_block_counter !=
547 548
		       ((s->data_block_counter + dbc_interval) & 0xff);
	}
549 550

	if (lost) {
551 552 553
		dev_err(&s->unit->device,
			"Detect discontinuity of CIP: %02X %02X\n",
			s->data_block_counter, data_block_counter);
554
		return -EIO;
555 556
	}

557 558
	syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK;
	pcm_frames = s->process_data_blocks(s, buffer + 2, data_blocks, &syt);
559

560 561 562 563
	if (s->flags & CIP_DBC_IS_END_EVENT)
		s->data_block_counter = data_block_counter;
	else
		s->data_block_counter =
564
				(data_block_counter + data_blocks) & 0xff;
565 566
end:
	if (queue_in_packet(s) < 0)
567
		return -EIO;
568

569 570 571
	pcm = ACCESS_ONCE(s->pcm);
	if (pcm && pcm_frames > 0)
		update_pcm_pointers(s, pcm, pcm_frames);
572

573
	return 0;
574 575
}

576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593
/*
 * In CYCLE_TIMER register of IEEE 1394, 7 bits are used to represent second. On
 * the other hand, in DMA descriptors of 1394 OHCI, 3 bits are used to represent
 * it. Thus, via Linux firewire subsystem, we can get the 3 bits for second.
 */
static inline u32 compute_cycle_count(u32 tstamp)
{
	return (((tstamp >> 13) & 0x07) * 8000) + (tstamp & 0x1fff);
}

static inline u32 increment_cycle_count(u32 cycle, unsigned int addend)
{
	cycle += addend;
	if (cycle >= 8 * CYCLES_PER_SECOND)
		cycle -= 8 * CYCLES_PER_SECOND;
	return cycle;
}

594 595 596 597 598 599 600
static inline u32 decrement_cycle_count(u32 cycle, unsigned int subtrahend)
{
	if (cycle < subtrahend)
		cycle += 8 * CYCLES_PER_SECOND;
	return cycle - subtrahend;
}

601
static void out_stream_callback(struct fw_iso_context *context, u32 tstamp,
602 603
				size_t header_length, void *header,
				void *private_data)
604
{
605
	struct amdtp_stream *s = private_data;
606
	unsigned int i, packets = header_length / 4;
607
	u32 cycle;
608

609 610 611
	if (s->packet_index < 0)
		return;

612 613 614 615
	cycle = compute_cycle_count(tstamp);

	/* Align to actual cycle count for the last packet. */
	cycle = increment_cycle_count(cycle, QUEUE_LENGTH - packets);
616

617
	for (i = 0; i < packets; ++i) {
618
		cycle = increment_cycle_count(cycle, 1);
619
		if (handle_out_packet(s, 0, cycle, i) < 0) {
620 621 622 623
			s->packet_index = -1;
			amdtp_stream_pcm_abort(s);
			return;
		}
624
	}
625

626
	fw_iso_context_queue_flush(s->context);
627 628
}

629
static void in_stream_callback(struct fw_iso_context *context, u32 tstamp,
630 631 632 633
			       size_t header_length, void *header,
			       void *private_data)
{
	struct amdtp_stream *s = private_data;
634
	unsigned int i, packets;
635
	unsigned int payload_length, max_payload_length;
636
	__be32 *headers = header;
637
	u32 cycle;
638

639 640 641
	if (s->packet_index < 0)
		return;

642 643 644
	/* The number of packets in buffer */
	packets = header_length / IN_PACKET_HEADER_SIZE;

645 646 647 648 649
	cycle = compute_cycle_count(tstamp);

	/* Align to actual cycle count for the last packet. */
	cycle = decrement_cycle_count(cycle, packets);

650
	/* For buffer-over-run prevention. */
651
	max_payload_length = amdtp_stream_get_max_payload(s);
652

653
	for (i = 0; i < packets; i++) {
654
		cycle = increment_cycle_count(cycle, 1);
655 656

		/* The number of quadlets in this packet */
657 658 659
		payload_length =
			(be32_to_cpu(headers[i]) >> ISO_DATA_LENGTH_SHIFT);
		if (payload_length > max_payload_length) {
660
			dev_err(&s->unit->device,
661 662
				"Detect jumbo payload: %04x %04x\n",
				payload_length, max_payload_length);
663 664 665
			break;
		}

666
		if (handle_in_packet(s, payload_length, cycle, i) < 0)
667
			break;
668 669
	}

670
	/* Queueing error or detecting invalid payload. */
671
	if (i < packets) {
672
		s->packet_index = -1;
673
		amdtp_stream_pcm_abort(s);
674 675 676
		return;
	}

677 678 679
	fw_iso_context_queue_flush(s->context);
}

680 681
/* this is executed one time */
static void amdtp_stream_first_callback(struct fw_iso_context *context,
682
					u32 tstamp, size_t header_length,
683 684 685
					void *header, void *private_data)
{
	struct amdtp_stream *s = private_data;
686 687
	u32 cycle;
	unsigned int packets;
688 689 690 691 692 693 694 695

	/*
	 * For in-stream, first packet has come.
	 * For out-stream, prepared to transmit first packet
	 */
	s->callbacked = true;
	wake_up(&s->callback_wait);

696 697 698 699 700
	cycle = compute_cycle_count(tstamp);

	if (s->direction == AMDTP_IN_STREAM) {
		packets = header_length / IN_PACKET_HEADER_SIZE;
		cycle = decrement_cycle_count(cycle, packets);
701
		context->callback.sc = in_stream_callback;
702 703 704
	} else {
		packets = header_length / 4;
		cycle = increment_cycle_count(cycle, QUEUE_LENGTH - packets);
705
		context->callback.sc = out_stream_callback;
706 707 708
	}

	s->start_cycle = cycle;
709

710
	context->callback.sc(context, tstamp, header_length, header, s);
711 712
}

713
/**
714 715
 * amdtp_stream_start - start transferring packets
 * @s: the AMDTP stream to start
716 717 718 719
 * @channel: the isochronous channel on the bus
 * @speed: firewire speed code
 *
 * The stream cannot be started until it has been configured with
720 721
 * amdtp_stream_set_parameters() and it must be started before any PCM or MIDI
 * device can be started.
722
 */
723
int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
724 725 726 727 728 729 730 731 732 733 734 735 736
{
	static const struct {
		unsigned int data_block;
		unsigned int syt_offset;
	} initial_state[] = {
		[CIP_SFC_32000]  = {  4, 3072 },
		[CIP_SFC_48000]  = {  6, 1024 },
		[CIP_SFC_96000]  = { 12, 1024 },
		[CIP_SFC_192000] = { 24, 1024 },
		[CIP_SFC_44100]  = {  0,   67 },
		[CIP_SFC_88200]  = {  0,   67 },
		[CIP_SFC_176400] = {  0,   67 },
	};
737 738
	unsigned int header_size;
	enum dma_data_direction dir;
739
	int type, tag, err;
740 741 742

	mutex_lock(&s->mutex);

743
	if (WARN_ON(amdtp_stream_running(s) ||
744
		    (s->data_block_quadlets < 1))) {
745 746 747 748
		err = -EBADFD;
		goto err_unlock;
	}

749
	if (s->direction == AMDTP_IN_STREAM)
750 751 752
		s->data_block_counter = UINT_MAX;
	else
		s->data_block_counter = 0;
753 754 755 756
	s->data_block_state = initial_state[s->sfc].data_block;
	s->syt_offset_state = initial_state[s->sfc].syt_offset;
	s->last_syt_offset = TICKS_PER_CYCLE;

757 758 759 760 761 762 763 764 765 766
	/* initialize packet buffer */
	if (s->direction == AMDTP_IN_STREAM) {
		dir = DMA_FROM_DEVICE;
		type = FW_ISO_CONTEXT_RECEIVE;
		header_size = IN_PACKET_HEADER_SIZE;
	} else {
		dir = DMA_TO_DEVICE;
		type = FW_ISO_CONTEXT_TRANSMIT;
		header_size = OUT_PACKET_HEADER_SIZE;
	}
767
	err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
768
				      amdtp_stream_get_max_payload(s), dir);
769 770 771 772
	if (err < 0)
		goto err_unlock;

	s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
773
					   type, channel, speed, header_size,
774
					   amdtp_stream_first_callback, s);
775 776 777 778
	if (IS_ERR(s->context)) {
		err = PTR_ERR(s->context);
		if (err == -EBUSY)
			dev_err(&s->unit->device,
779
				"no free stream on this controller\n");
780 781 782
		goto err_buffer;
	}

783
	amdtp_stream_update(s);
784

785
	s->packet_index = 0;
786
	do {
787 788 789
		if (s->direction == AMDTP_IN_STREAM)
			err = queue_in_packet(s);
		else
790
			err = queue_out_packet(s, 0);
791 792 793
		if (err < 0)
			goto err_context;
	} while (s->packet_index > 0);
794

795
	/* NOTE: TAG1 matches CIP. This just affects in stream. */
796 797 798 799
	tag = FW_ISO_CONTEXT_MATCH_TAG1;
	if (s->flags & CIP_EMPTY_WITH_TAG0)
		tag |= FW_ISO_CONTEXT_MATCH_TAG0;

800
	s->callbacked = false;
801
	err = fw_iso_context_start(s->context, -1, 0, tag);
802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818
	if (err < 0)
		goto err_context;

	mutex_unlock(&s->mutex);

	return 0;

err_context:
	fw_iso_context_destroy(s->context);
	s->context = ERR_PTR(-1);
err_buffer:
	iso_packets_buffer_destroy(&s->buffer, s->unit);
err_unlock:
	mutex_unlock(&s->mutex);

	return err;
}
819
EXPORT_SYMBOL(amdtp_stream_start);
820

821
/**
822 823
 * amdtp_stream_pcm_pointer - get the PCM buffer position
 * @s: the AMDTP stream that transports the PCM data
824 825 826
 *
 * Returns the current buffer position, in frames.
 */
827
unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s)
828
{
829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845
	/*
	 * This function is called in software IRQ context of period_tasklet or
	 * process context.
	 *
	 * When the software IRQ context was scheduled by software IRQ context
	 * of IR/IT contexts, queued packets were already handled. Therefore,
	 * no need to flush the queue in buffer anymore.
	 *
	 * When the process context reach here, some packets will be already
	 * queued in the buffer. These packets should be handled immediately
	 * to keep better granularity of PCM pointer.
	 *
	 * Later, the process context will sometimes schedules software IRQ
	 * context of the period_tasklet. Then, no need to flush the queue by
	 * the same reason as described for IR/IT contexts.
	 */
	if (!in_interrupt() && amdtp_stream_running(s))
846
		fw_iso_context_flush_completions(s->context);
847 848 849

	return ACCESS_ONCE(s->pcm_buffer_pointer);
}
850
EXPORT_SYMBOL(amdtp_stream_pcm_pointer);
851

852
/**
853 854
 * amdtp_stream_update - update the stream after a bus reset
 * @s: the AMDTP stream
855
 */
856
void amdtp_stream_update(struct amdtp_stream *s)
857
{
858
	/* Precomputing. */
859
	ACCESS_ONCE(s->source_node_id_field) =
860 861
		(fw_parent_device(s->unit)->card->node_id << CIP_SID_SHIFT) &
								CIP_SID_MASK;
862
}
863
EXPORT_SYMBOL(amdtp_stream_update);
864 865

/**
866 867
 * amdtp_stream_stop - stop sending packets
 * @s: the AMDTP stream to stop
868 869 870 871
 *
 * All PCM and MIDI devices of the stream must be stopped before the stream
 * itself can be stopped.
 */
872
void amdtp_stream_stop(struct amdtp_stream *s)
873 874 875
{
	mutex_lock(&s->mutex);

876
	if (!amdtp_stream_running(s)) {
877 878 879 880
		mutex_unlock(&s->mutex);
		return;
	}

881
	tasklet_kill(&s->period_tasklet);
882 883 884 885 886
	fw_iso_context_stop(s->context);
	fw_iso_context_destroy(s->context);
	s->context = ERR_PTR(-1);
	iso_packets_buffer_destroy(&s->buffer, s->unit);

887 888
	s->callbacked = false;

889 890
	mutex_unlock(&s->mutex);
}
891
EXPORT_SYMBOL(amdtp_stream_stop);
892 893

/**
894
 * amdtp_stream_pcm_abort - abort the running PCM device
895 896 897 898 899
 * @s: the AMDTP stream about to be stopped
 *
 * If the isochronous stream needs to be stopped asynchronously, call this
 * function first to stop the PCM device.
 */
900
void amdtp_stream_pcm_abort(struct amdtp_stream *s)
901 902 903 904
{
	struct snd_pcm_substream *pcm;

	pcm = ACCESS_ONCE(s->pcm);
905 906
	if (pcm)
		snd_pcm_stop_xrun(pcm);
907
}
908
EXPORT_SYMBOL(amdtp_stream_pcm_abort);