1 /* 2 * Audio and Music Data Transmission Protocol (IEC 61883-6) streams 3 * with Common Isochronous Packet (IEC 61883-1) headers 4 * 5 * Copyright (c) Clemens Ladisch <clemens@ladisch.de> 6 * Licensed under the terms of the GNU General Public License, version 2. 7 */ 8 9 #include <linux/device.h> 10 #include <linux/err.h> 11 #include <linux/firewire.h> 12 #include <linux/module.h> 13 #include <linux/slab.h> 14 #include <sound/pcm.h> 15 #include <sound/pcm_params.h> 16 #include "amdtp-stream.h" 17 18 #define TICKS_PER_CYCLE 3072 19 #define CYCLES_PER_SECOND 8000 20 #define TICKS_PER_SECOND (TICKS_PER_CYCLE * CYCLES_PER_SECOND) 21 22 #define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 microseconds */ 23 24 /* isochronous header parameters */ 25 #define ISO_DATA_LENGTH_SHIFT 16 26 #define TAG_CIP 1 27 28 /* common isochronous packet header parameters */ 29 #define CIP_EOH_SHIFT 31 30 #define CIP_EOH (1u << CIP_EOH_SHIFT) 31 #define CIP_EOH_MASK 0x80000000 32 #define CIP_SID_SHIFT 24 33 #define CIP_SID_MASK 0x3f000000 34 #define CIP_DBS_MASK 0x00ff0000 35 #define CIP_DBS_SHIFT 16 36 #define CIP_DBC_MASK 0x000000ff 37 #define CIP_FMT_SHIFT 24 38 #define CIP_FMT_MASK 0x3f000000 39 #define CIP_FDF_MASK 0x00ff0000 40 #define CIP_FDF_SHIFT 16 41 #define CIP_SYT_MASK 0x0000ffff 42 #define CIP_SYT_NO_INFO 0xffff 43 44 /* Audio and Music transfer protocol specific parameters */ 45 #define CIP_FMT_AM 0x10 46 #define AMDTP_FDF_NO_DATA 0xff 47 48 /* TODO: make these configurable */ 49 #define INTERRUPT_INTERVAL 16 50 #define QUEUE_LENGTH 48 51 52 #define IN_PACKET_HEADER_SIZE 4 53 #define OUT_PACKET_HEADER_SIZE 0 54 55 static void pcm_period_tasklet(unsigned long data); 56 57 /** 58 * amdtp_stream_init - initialize an AMDTP stream structure 59 * @s: the AMDTP stream to initialize 60 * @unit: the target of the stream 61 * @dir: the direction of stream 62 * @flags: the packet transmission method to use 63 * @fmt: the value of fmt field in CIP header 64 * @process_data_blocks: callback handler to process data blocks 65 * @protocol_size: the size to allocate newly for protocol 66 */ 67 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit, 68 enum amdtp_stream_direction dir, enum cip_flags flags, 69 unsigned int fmt, 70 amdtp_stream_process_data_blocks_t process_data_blocks, 71 unsigned int protocol_size) 72 { 73 if (process_data_blocks == NULL) 74 return -EINVAL; 75 76 s->protocol = kzalloc(protocol_size, GFP_KERNEL); 77 if (!s->protocol) 78 return -ENOMEM; 79 80 s->unit = unit; 81 s->direction = dir; 82 s->flags = flags; 83 s->context = ERR_PTR(-1); 84 mutex_init(&s->mutex); 85 tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s); 86 s->packet_index = 0; 87 88 init_waitqueue_head(&s->callback_wait); 89 s->callbacked = false; 90 s->sync_slave = NULL; 91 92 s->fmt = fmt; 93 s->process_data_blocks = process_data_blocks; 94 95 return 0; 96 } 97 EXPORT_SYMBOL(amdtp_stream_init); 98 99 /** 100 * amdtp_stream_destroy - free stream resources 101 * @s: the AMDTP stream to destroy 102 */ 103 void amdtp_stream_destroy(struct amdtp_stream *s) 104 { 105 WARN_ON(amdtp_stream_running(s)); 106 kfree(s->protocol); 107 mutex_destroy(&s->mutex); 108 } 109 EXPORT_SYMBOL(amdtp_stream_destroy); 110 111 const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = { 112 [CIP_SFC_32000] = 8, 113 [CIP_SFC_44100] = 8, 114 [CIP_SFC_48000] = 8, 115 [CIP_SFC_88200] = 16, 116 [CIP_SFC_96000] = 16, 117 [CIP_SFC_176400] = 32, 118 [CIP_SFC_192000] = 32, 119 }; 120 EXPORT_SYMBOL(amdtp_syt_intervals); 121 122 const unsigned int amdtp_rate_table[CIP_SFC_COUNT] = { 123 [CIP_SFC_32000] = 32000, 124 [CIP_SFC_44100] = 44100, 125 [CIP_SFC_48000] = 48000, 126 [CIP_SFC_88200] = 88200, 127 [CIP_SFC_96000] = 96000, 128 [CIP_SFC_176400] = 176400, 129 [CIP_SFC_192000] = 192000, 130 }; 131 EXPORT_SYMBOL(amdtp_rate_table); 132 133 /** 134 * amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream 135 * @s: the AMDTP stream, which must be initialized. 136 * @runtime: the PCM substream runtime 137 */ 138 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s, 139 struct snd_pcm_runtime *runtime) 140 { 141 int err; 142 143 /* 144 * Currently firewire-lib processes 16 packets in one software 145 * interrupt callback. This equals to 2msec but actually the 146 * interval of the interrupts has a jitter. 147 * Additionally, even if adding a constraint to fit period size to 148 * 2msec, actual calculated frames per period doesn't equal to 2msec, 149 * depending on sampling rate. 150 * Anyway, the interval to call snd_pcm_period_elapsed() cannot 2msec. 151 * Here let us use 5msec for safe period interrupt. 152 */ 153 err = snd_pcm_hw_constraint_minmax(runtime, 154 SNDRV_PCM_HW_PARAM_PERIOD_TIME, 155 5000, UINT_MAX); 156 if (err < 0) 157 goto end; 158 159 /* Non-Blocking stream has no more constraints */ 160 if (!(s->flags & CIP_BLOCKING)) 161 goto end; 162 163 /* 164 * One AMDTP packet can include some frames. In blocking mode, the 165 * number equals to SYT_INTERVAL. So the number is 8, 16 or 32, 166 * depending on its sampling rate. For accurate period interrupt, it's 167 * preferrable to align period/buffer sizes to current SYT_INTERVAL. 168 * 169 * TODO: These constraints can be improved with proper rules. 170 * Currently apply LCM of SYT_INTERVALs. 171 */ 172 err = snd_pcm_hw_constraint_step(runtime, 0, 173 SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 32); 174 if (err < 0) 175 goto end; 176 err = snd_pcm_hw_constraint_step(runtime, 0, 177 SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 32); 178 end: 179 return err; 180 } 181 EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints); 182 183 /** 184 * amdtp_stream_set_parameters - set stream parameters 185 * @s: the AMDTP stream to configure 186 * @rate: the sample rate 187 * @data_block_quadlets: the size of a data block in quadlet unit 188 * 189 * The parameters must be set before the stream is started, and must not be 190 * changed while the stream is running. 191 */ 192 int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate, 193 unsigned int data_block_quadlets) 194 { 195 unsigned int sfc; 196 197 for (sfc = 0; sfc < ARRAY_SIZE(amdtp_rate_table); ++sfc) { 198 if (amdtp_rate_table[sfc] == rate) 199 break; 200 } 201 if (sfc == ARRAY_SIZE(amdtp_rate_table)) 202 return -EINVAL; 203 204 s->sfc = sfc; 205 s->data_block_quadlets = data_block_quadlets; 206 s->syt_interval = amdtp_syt_intervals[sfc]; 207 208 /* default buffering in the device */ 209 s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE; 210 if (s->flags & CIP_BLOCKING) 211 /* additional buffering needed to adjust for no-data packets */ 212 s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate; 213 214 return 0; 215 } 216 EXPORT_SYMBOL(amdtp_stream_set_parameters); 217 218 /** 219 * amdtp_stream_get_max_payload - get the stream's packet size 220 * @s: the AMDTP stream 221 * 222 * This function must not be called before the stream has been configured 223 * with amdtp_stream_set_parameters(). 224 */ 225 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s) 226 { 227 unsigned int multiplier = 1; 228 229 if (s->flags & CIP_JUMBO_PAYLOAD) 230 multiplier = 5; 231 232 return 8 + s->syt_interval * s->data_block_quadlets * 4 * multiplier; 233 } 234 EXPORT_SYMBOL(amdtp_stream_get_max_payload); 235 236 /** 237 * amdtp_stream_pcm_prepare - prepare PCM device for running 238 * @s: the AMDTP stream 239 * 240 * This function should be called from the PCM device's .prepare callback. 241 */ 242 void amdtp_stream_pcm_prepare(struct amdtp_stream *s) 243 { 244 tasklet_kill(&s->period_tasklet); 245 s->pcm_buffer_pointer = 0; 246 s->pcm_period_pointer = 0; 247 s->pointer_flush = true; 248 } 249 EXPORT_SYMBOL(amdtp_stream_pcm_prepare); 250 251 static unsigned int calculate_data_blocks(struct amdtp_stream *s, 252 unsigned int syt) 253 { 254 unsigned int phase, data_blocks; 255 256 /* Blocking mode. */ 257 if (s->flags & CIP_BLOCKING) { 258 /* This module generate empty packet for 'no data'. */ 259 if (syt == CIP_SYT_NO_INFO) 260 data_blocks = 0; 261 else 262 data_blocks = s->syt_interval; 263 /* Non-blocking mode. */ 264 } else { 265 if (!cip_sfc_is_base_44100(s->sfc)) { 266 /* Sample_rate / 8000 is an integer, and precomputed. */ 267 data_blocks = s->data_block_state; 268 } else { 269 phase = s->data_block_state; 270 271 /* 272 * This calculates the number of data blocks per packet so that 273 * 1) the overall rate is correct and exactly synchronized to 274 * the bus clock, and 275 * 2) packets with a rounded-up number of blocks occur as early 276 * as possible in the sequence (to prevent underruns of the 277 * device's buffer). 278 */ 279 if (s->sfc == CIP_SFC_44100) 280 /* 6 6 5 6 5 6 5 ... */ 281 data_blocks = 5 + ((phase & 1) ^ 282 (phase == 0 || phase >= 40)); 283 else 284 /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */ 285 data_blocks = 11 * (s->sfc >> 1) + (phase == 0); 286 if (++phase >= (80 >> (s->sfc >> 1))) 287 phase = 0; 288 s->data_block_state = phase; 289 } 290 } 291 292 return data_blocks; 293 } 294 295 static unsigned int calculate_syt(struct amdtp_stream *s, 296 unsigned int cycle) 297 { 298 unsigned int syt_offset, phase, index, syt; 299 300 if (s->last_syt_offset < TICKS_PER_CYCLE) { 301 if (!cip_sfc_is_base_44100(s->sfc)) 302 syt_offset = s->last_syt_offset + s->syt_offset_state; 303 else { 304 /* 305 * The time, in ticks, of the n'th SYT_INTERVAL sample is: 306 * n * SYT_INTERVAL * 24576000 / sample_rate 307 * Modulo TICKS_PER_CYCLE, the difference between successive 308 * elements is about 1386.23. Rounding the results of this 309 * formula to the SYT precision results in a sequence of 310 * differences that begins with: 311 * 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ... 312 * This code generates _exactly_ the same sequence. 313 */ 314 phase = s->syt_offset_state; 315 index = phase % 13; 316 syt_offset = s->last_syt_offset; 317 syt_offset += 1386 + ((index && !(index & 3)) || 318 phase == 146); 319 if (++phase >= 147) 320 phase = 0; 321 s->syt_offset_state = phase; 322 } 323 } else 324 syt_offset = s->last_syt_offset - TICKS_PER_CYCLE; 325 s->last_syt_offset = syt_offset; 326 327 if (syt_offset < TICKS_PER_CYCLE) { 328 syt_offset += s->transfer_delay; 329 syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12; 330 syt += syt_offset % TICKS_PER_CYCLE; 331 332 return syt & CIP_SYT_MASK; 333 } else { 334 return CIP_SYT_NO_INFO; 335 } 336 } 337 338 static void update_pcm_pointers(struct amdtp_stream *s, 339 struct snd_pcm_substream *pcm, 340 unsigned int frames) 341 { 342 unsigned int ptr; 343 344 ptr = s->pcm_buffer_pointer + frames; 345 if (ptr >= pcm->runtime->buffer_size) 346 ptr -= pcm->runtime->buffer_size; 347 ACCESS_ONCE(s->pcm_buffer_pointer) = ptr; 348 349 s->pcm_period_pointer += frames; 350 if (s->pcm_period_pointer >= pcm->runtime->period_size) { 351 s->pcm_period_pointer -= pcm->runtime->period_size; 352 s->pointer_flush = false; 353 tasklet_hi_schedule(&s->period_tasklet); 354 } 355 } 356 357 static void pcm_period_tasklet(unsigned long data) 358 { 359 struct amdtp_stream *s = (void *)data; 360 struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm); 361 362 if (pcm) 363 snd_pcm_period_elapsed(pcm); 364 } 365 366 static int queue_packet(struct amdtp_stream *s, 367 unsigned int header_length, 368 unsigned int payload_length, bool skip) 369 { 370 struct fw_iso_packet p = {0}; 371 int err = 0; 372 373 if (IS_ERR(s->context)) 374 goto end; 375 376 p.interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL); 377 p.tag = TAG_CIP; 378 p.header_length = header_length; 379 p.payload_length = (!skip) ? payload_length : 0; 380 p.skip = skip; 381 err = fw_iso_context_queue(s->context, &p, &s->buffer.iso_buffer, 382 s->buffer.packets[s->packet_index].offset); 383 if (err < 0) { 384 dev_err(&s->unit->device, "queueing error: %d\n", err); 385 goto end; 386 } 387 388 if (++s->packet_index >= QUEUE_LENGTH) 389 s->packet_index = 0; 390 end: 391 return err; 392 } 393 394 static inline int queue_out_packet(struct amdtp_stream *s, 395 unsigned int payload_length, bool skip) 396 { 397 return queue_packet(s, OUT_PACKET_HEADER_SIZE, 398 payload_length, skip); 399 } 400 401 static inline int queue_in_packet(struct amdtp_stream *s) 402 { 403 return queue_packet(s, IN_PACKET_HEADER_SIZE, 404 amdtp_stream_get_max_payload(s), false); 405 } 406 407 static int handle_out_packet(struct amdtp_stream *s, unsigned int data_blocks, 408 unsigned int syt) 409 { 410 __be32 *buffer; 411 unsigned int payload_length; 412 unsigned int pcm_frames; 413 struct snd_pcm_substream *pcm; 414 415 buffer = s->buffer.packets[s->packet_index].buffer; 416 pcm_frames = s->process_data_blocks(s, buffer + 2, data_blocks, &syt); 417 418 buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) | 419 (s->data_block_quadlets << CIP_DBS_SHIFT) | 420 s->data_block_counter); 421 buffer[1] = cpu_to_be32(CIP_EOH | 422 ((s->fmt << CIP_FMT_SHIFT) & CIP_FMT_MASK) | 423 ((s->fdf << CIP_FDF_SHIFT) & CIP_FDF_MASK) | 424 (syt & CIP_SYT_MASK)); 425 426 s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff; 427 428 payload_length = 8 + data_blocks * 4 * s->data_block_quadlets; 429 if (queue_out_packet(s, payload_length, false) < 0) 430 return -EIO; 431 432 pcm = ACCESS_ONCE(s->pcm); 433 if (pcm && pcm_frames > 0) 434 update_pcm_pointers(s, pcm, pcm_frames); 435 436 /* No need to return the number of handled data blocks. */ 437 return 0; 438 } 439 440 static int handle_in_packet(struct amdtp_stream *s, 441 unsigned int payload_quadlets, __be32 *buffer, 442 unsigned int *data_blocks, unsigned int syt) 443 { 444 u32 cip_header[2]; 445 unsigned int fmt, fdf; 446 unsigned int data_block_quadlets, data_block_counter, dbc_interval; 447 struct snd_pcm_substream *pcm; 448 unsigned int pcm_frames; 449 bool lost; 450 451 cip_header[0] = be32_to_cpu(buffer[0]); 452 cip_header[1] = be32_to_cpu(buffer[1]); 453 454 /* 455 * This module supports 'Two-quadlet CIP header with SYT field'. 456 * For convenience, also check FMT field is AM824 or not. 457 */ 458 if (((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) || 459 ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH)) { 460 dev_info_ratelimited(&s->unit->device, 461 "Invalid CIP header for AMDTP: %08X:%08X\n", 462 cip_header[0], cip_header[1]); 463 *data_blocks = 0; 464 pcm_frames = 0; 465 goto end; 466 } 467 468 /* Check valid protocol or not. */ 469 fmt = (cip_header[1] & CIP_FMT_MASK) >> CIP_FMT_SHIFT; 470 if (fmt != s->fmt) { 471 dev_info_ratelimited(&s->unit->device, 472 "Detect unexpected protocol: %08x %08x\n", 473 cip_header[0], cip_header[1]); 474 *data_blocks = 0; 475 pcm_frames = 0; 476 goto end; 477 } 478 479 /* Calculate data blocks */ 480 fdf = (cip_header[1] & CIP_FDF_MASK) >> CIP_FDF_SHIFT; 481 if (payload_quadlets < 3 || 482 (fmt == CIP_FMT_AM && fdf == AMDTP_FDF_NO_DATA)) { 483 *data_blocks = 0; 484 } else { 485 data_block_quadlets = 486 (cip_header[0] & CIP_DBS_MASK) >> CIP_DBS_SHIFT; 487 /* avoid division by zero */ 488 if (data_block_quadlets == 0) { 489 dev_err(&s->unit->device, 490 "Detect invalid value in dbs field: %08X\n", 491 cip_header[0]); 492 return -EPROTO; 493 } 494 if (s->flags & CIP_WRONG_DBS) 495 data_block_quadlets = s->data_block_quadlets; 496 497 *data_blocks = (payload_quadlets - 2) / data_block_quadlets; 498 } 499 500 /* Check data block counter continuity */ 501 data_block_counter = cip_header[0] & CIP_DBC_MASK; 502 if (*data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) && 503 s->data_block_counter != UINT_MAX) 504 data_block_counter = s->data_block_counter; 505 506 if (((s->flags & CIP_SKIP_DBC_ZERO_CHECK) && 507 data_block_counter == s->tx_first_dbc) || 508 s->data_block_counter == UINT_MAX) { 509 lost = false; 510 } else if (!(s->flags & CIP_DBC_IS_END_EVENT)) { 511 lost = data_block_counter != s->data_block_counter; 512 } else { 513 if ((*data_blocks > 0) && (s->tx_dbc_interval > 0)) 514 dbc_interval = s->tx_dbc_interval; 515 else 516 dbc_interval = *data_blocks; 517 518 lost = data_block_counter != 519 ((s->data_block_counter + dbc_interval) & 0xff); 520 } 521 522 if (lost) { 523 dev_err(&s->unit->device, 524 "Detect discontinuity of CIP: %02X %02X\n", 525 s->data_block_counter, data_block_counter); 526 return -EIO; 527 } 528 529 pcm_frames = s->process_data_blocks(s, buffer + 2, *data_blocks, &syt); 530 531 if (s->flags & CIP_DBC_IS_END_EVENT) 532 s->data_block_counter = data_block_counter; 533 else 534 s->data_block_counter = 535 (data_block_counter + *data_blocks) & 0xff; 536 end: 537 if (queue_in_packet(s) < 0) 538 return -EIO; 539 540 pcm = ACCESS_ONCE(s->pcm); 541 if (pcm && pcm_frames > 0) 542 update_pcm_pointers(s, pcm, pcm_frames); 543 544 return 0; 545 } 546 547 static void out_stream_callback(struct fw_iso_context *context, u32 cycle, 548 size_t header_length, void *header, 549 void *private_data) 550 { 551 struct amdtp_stream *s = private_data; 552 unsigned int i, syt, packets = header_length / 4; 553 unsigned int data_blocks; 554 555 if (s->packet_index < 0) 556 return; 557 558 /* 559 * Compute the cycle of the last queued packet. 560 * (We need only the four lowest bits for the SYT, so we can ignore 561 * that bits 0-11 must wrap around at 3072.) 562 */ 563 cycle += QUEUE_LENGTH - packets; 564 565 for (i = 0; i < packets; ++i) { 566 syt = calculate_syt(s, ++cycle); 567 data_blocks = calculate_data_blocks(s, syt); 568 569 if (handle_out_packet(s, data_blocks, syt) < 0) { 570 s->packet_index = -1; 571 amdtp_stream_pcm_abort(s); 572 return; 573 } 574 } 575 576 fw_iso_context_queue_flush(s->context); 577 } 578 579 static void in_stream_callback(struct fw_iso_context *context, u32 cycle, 580 size_t header_length, void *header, 581 void *private_data) 582 { 583 struct amdtp_stream *s = private_data; 584 unsigned int p, syt, packets; 585 unsigned int payload_quadlets, max_payload_quadlets; 586 unsigned int data_blocks; 587 __be32 *buffer, *headers = header; 588 589 if (s->packet_index < 0) 590 return; 591 592 /* The number of packets in buffer */ 593 packets = header_length / IN_PACKET_HEADER_SIZE; 594 595 /* For buffer-over-run prevention. */ 596 max_payload_quadlets = amdtp_stream_get_max_payload(s) / 4; 597 598 for (p = 0; p < packets; p++) { 599 buffer = s->buffer.packets[s->packet_index].buffer; 600 601 /* The number of quadlets in this packet */ 602 payload_quadlets = 603 (be32_to_cpu(headers[p]) >> ISO_DATA_LENGTH_SHIFT) / 4; 604 if (payload_quadlets > max_payload_quadlets) { 605 dev_err(&s->unit->device, 606 "Detect jumbo payload: %02x %02x\n", 607 payload_quadlets, max_payload_quadlets); 608 s->packet_index = -1; 609 break; 610 } 611 612 syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK; 613 if (handle_in_packet(s, payload_quadlets, buffer, 614 &data_blocks, syt) < 0) { 615 s->packet_index = -1; 616 break; 617 } 618 619 /* Process sync slave stream */ 620 if (s->sync_slave && s->sync_slave->callbacked) { 621 if (handle_out_packet(s->sync_slave, 622 data_blocks, syt) < 0) { 623 s->packet_index = -1; 624 break; 625 } 626 } 627 } 628 629 /* Queueing error or detecting discontinuity */ 630 if (s->packet_index < 0) { 631 amdtp_stream_pcm_abort(s); 632 633 /* Abort sync slave. */ 634 if (s->sync_slave) { 635 s->sync_slave->packet_index = -1; 636 amdtp_stream_pcm_abort(s->sync_slave); 637 } 638 return; 639 } 640 641 /* when sync to device, flush the packets for slave stream */ 642 if (s->sync_slave && s->sync_slave->callbacked) 643 fw_iso_context_queue_flush(s->sync_slave->context); 644 645 fw_iso_context_queue_flush(s->context); 646 } 647 648 /* processing is done by master callback */ 649 static void slave_stream_callback(struct fw_iso_context *context, u32 cycle, 650 size_t header_length, void *header, 651 void *private_data) 652 { 653 return; 654 } 655 656 /* this is executed one time */ 657 static void amdtp_stream_first_callback(struct fw_iso_context *context, 658 u32 cycle, size_t header_length, 659 void *header, void *private_data) 660 { 661 struct amdtp_stream *s = private_data; 662 663 /* 664 * For in-stream, first packet has come. 665 * For out-stream, prepared to transmit first packet 666 */ 667 s->callbacked = true; 668 wake_up(&s->callback_wait); 669 670 if (s->direction == AMDTP_IN_STREAM) 671 context->callback.sc = in_stream_callback; 672 else if (s->flags & CIP_SYNC_TO_DEVICE) 673 context->callback.sc = slave_stream_callback; 674 else 675 context->callback.sc = out_stream_callback; 676 677 context->callback.sc(context, cycle, header_length, header, s); 678 } 679 680 /** 681 * amdtp_stream_start - start transferring packets 682 * @s: the AMDTP stream to start 683 * @channel: the isochronous channel on the bus 684 * @speed: firewire speed code 685 * 686 * The stream cannot be started until it has been configured with 687 * amdtp_stream_set_parameters() and it must be started before any PCM or MIDI 688 * device can be started. 689 */ 690 int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed) 691 { 692 static const struct { 693 unsigned int data_block; 694 unsigned int syt_offset; 695 } initial_state[] = { 696 [CIP_SFC_32000] = { 4, 3072 }, 697 [CIP_SFC_48000] = { 6, 1024 }, 698 [CIP_SFC_96000] = { 12, 1024 }, 699 [CIP_SFC_192000] = { 24, 1024 }, 700 [CIP_SFC_44100] = { 0, 67 }, 701 [CIP_SFC_88200] = { 0, 67 }, 702 [CIP_SFC_176400] = { 0, 67 }, 703 }; 704 unsigned int header_size; 705 enum dma_data_direction dir; 706 int type, tag, err; 707 708 mutex_lock(&s->mutex); 709 710 if (WARN_ON(amdtp_stream_running(s) || 711 (s->data_block_quadlets < 1))) { 712 err = -EBADFD; 713 goto err_unlock; 714 } 715 716 if (s->direction == AMDTP_IN_STREAM && 717 s->flags & CIP_SKIP_INIT_DBC_CHECK) 718 s->data_block_counter = UINT_MAX; 719 else 720 s->data_block_counter = 0; 721 s->data_block_state = initial_state[s->sfc].data_block; 722 s->syt_offset_state = initial_state[s->sfc].syt_offset; 723 s->last_syt_offset = TICKS_PER_CYCLE; 724 725 /* initialize packet buffer */ 726 if (s->direction == AMDTP_IN_STREAM) { 727 dir = DMA_FROM_DEVICE; 728 type = FW_ISO_CONTEXT_RECEIVE; 729 header_size = IN_PACKET_HEADER_SIZE; 730 } else { 731 dir = DMA_TO_DEVICE; 732 type = FW_ISO_CONTEXT_TRANSMIT; 733 header_size = OUT_PACKET_HEADER_SIZE; 734 } 735 err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH, 736 amdtp_stream_get_max_payload(s), dir); 737 if (err < 0) 738 goto err_unlock; 739 740 s->context = fw_iso_context_create(fw_parent_device(s->unit)->card, 741 type, channel, speed, header_size, 742 amdtp_stream_first_callback, s); 743 if (IS_ERR(s->context)) { 744 err = PTR_ERR(s->context); 745 if (err == -EBUSY) 746 dev_err(&s->unit->device, 747 "no free stream on this controller\n"); 748 goto err_buffer; 749 } 750 751 amdtp_stream_update(s); 752 753 s->packet_index = 0; 754 do { 755 if (s->direction == AMDTP_IN_STREAM) 756 err = queue_in_packet(s); 757 else 758 err = queue_out_packet(s, 0, true); 759 if (err < 0) 760 goto err_context; 761 } while (s->packet_index > 0); 762 763 /* NOTE: TAG1 matches CIP. This just affects in stream. */ 764 tag = FW_ISO_CONTEXT_MATCH_TAG1; 765 if (s->flags & CIP_EMPTY_WITH_TAG0) 766 tag |= FW_ISO_CONTEXT_MATCH_TAG0; 767 768 s->callbacked = false; 769 err = fw_iso_context_start(s->context, -1, 0, tag); 770 if (err < 0) 771 goto err_context; 772 773 mutex_unlock(&s->mutex); 774 775 return 0; 776 777 err_context: 778 fw_iso_context_destroy(s->context); 779 s->context = ERR_PTR(-1); 780 err_buffer: 781 iso_packets_buffer_destroy(&s->buffer, s->unit); 782 err_unlock: 783 mutex_unlock(&s->mutex); 784 785 return err; 786 } 787 EXPORT_SYMBOL(amdtp_stream_start); 788 789 /** 790 * amdtp_stream_pcm_pointer - get the PCM buffer position 791 * @s: the AMDTP stream that transports the PCM data 792 * 793 * Returns the current buffer position, in frames. 794 */ 795 unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s) 796 { 797 /* this optimization is allowed to be racy */ 798 if (s->pointer_flush && amdtp_stream_running(s)) 799 fw_iso_context_flush_completions(s->context); 800 else 801 s->pointer_flush = true; 802 803 return ACCESS_ONCE(s->pcm_buffer_pointer); 804 } 805 EXPORT_SYMBOL(amdtp_stream_pcm_pointer); 806 807 /** 808 * amdtp_stream_update - update the stream after a bus reset 809 * @s: the AMDTP stream 810 */ 811 void amdtp_stream_update(struct amdtp_stream *s) 812 { 813 /* Precomputing. */ 814 ACCESS_ONCE(s->source_node_id_field) = 815 (fw_parent_device(s->unit)->card->node_id << CIP_SID_SHIFT) & 816 CIP_SID_MASK; 817 } 818 EXPORT_SYMBOL(amdtp_stream_update); 819 820 /** 821 * amdtp_stream_stop - stop sending packets 822 * @s: the AMDTP stream to stop 823 * 824 * All PCM and MIDI devices of the stream must be stopped before the stream 825 * itself can be stopped. 826 */ 827 void amdtp_stream_stop(struct amdtp_stream *s) 828 { 829 mutex_lock(&s->mutex); 830 831 if (!amdtp_stream_running(s)) { 832 mutex_unlock(&s->mutex); 833 return; 834 } 835 836 tasklet_kill(&s->period_tasklet); 837 fw_iso_context_stop(s->context); 838 fw_iso_context_destroy(s->context); 839 s->context = ERR_PTR(-1); 840 iso_packets_buffer_destroy(&s->buffer, s->unit); 841 842 s->callbacked = false; 843 844 mutex_unlock(&s->mutex); 845 } 846 EXPORT_SYMBOL(amdtp_stream_stop); 847 848 /** 849 * amdtp_stream_pcm_abort - abort the running PCM device 850 * @s: the AMDTP stream about to be stopped 851 * 852 * If the isochronous stream needs to be stopped asynchronously, call this 853 * function first to stop the PCM device. 854 */ 855 void amdtp_stream_pcm_abort(struct amdtp_stream *s) 856 { 857 struct snd_pcm_substream *pcm; 858 859 pcm = ACCESS_ONCE(s->pcm); 860 if (pcm) 861 snd_pcm_stop_xrun(pcm); 862 } 863 EXPORT_SYMBOL(amdtp_stream_pcm_abort); 864