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 /* Always support Linux tracing subsystem. */ 23 #define CREATE_TRACE_POINTS 24 #include "amdtp-stream-trace.h" 25 26 #define TRANSFER_DELAY_TICKS 0x2e00 /* 479.17 microseconds */ 27 28 /* isochronous header parameters */ 29 #define ISO_DATA_LENGTH_SHIFT 16 30 #define TAG_CIP 1 31 32 /* common isochronous packet header parameters */ 33 #define CIP_EOH_SHIFT 31 34 #define CIP_EOH (1u << CIP_EOH_SHIFT) 35 #define CIP_EOH_MASK 0x80000000 36 #define CIP_SID_SHIFT 24 37 #define CIP_SID_MASK 0x3f000000 38 #define CIP_DBS_MASK 0x00ff0000 39 #define CIP_DBS_SHIFT 16 40 #define CIP_DBC_MASK 0x000000ff 41 #define CIP_FMT_SHIFT 24 42 #define CIP_FMT_MASK 0x3f000000 43 #define CIP_FDF_MASK 0x00ff0000 44 #define CIP_FDF_SHIFT 16 45 #define CIP_SYT_MASK 0x0000ffff 46 #define CIP_SYT_NO_INFO 0xffff 47 48 /* Audio and Music transfer protocol specific parameters */ 49 #define CIP_FMT_AM 0x10 50 #define AMDTP_FDF_NO_DATA 0xff 51 52 /* TODO: make these configurable */ 53 #define INTERRUPT_INTERVAL 16 54 #define QUEUE_LENGTH 48 55 56 #define IN_PACKET_HEADER_SIZE 4 57 #define OUT_PACKET_HEADER_SIZE 0 58 59 static void pcm_period_tasklet(unsigned long data); 60 61 /** 62 * amdtp_stream_init - initialize an AMDTP stream structure 63 * @s: the AMDTP stream to initialize 64 * @unit: the target of the stream 65 * @dir: the direction of stream 66 * @flags: the packet transmission method to use 67 * @fmt: the value of fmt field in CIP header 68 * @process_data_blocks: callback handler to process data blocks 69 * @protocol_size: the size to allocate newly for protocol 70 */ 71 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit, 72 enum amdtp_stream_direction dir, enum cip_flags flags, 73 unsigned int fmt, 74 amdtp_stream_process_data_blocks_t process_data_blocks, 75 unsigned int protocol_size) 76 { 77 if (process_data_blocks == NULL) 78 return -EINVAL; 79 80 s->protocol = kzalloc(protocol_size, GFP_KERNEL); 81 if (!s->protocol) 82 return -ENOMEM; 83 84 s->unit = unit; 85 s->direction = dir; 86 s->flags = flags; 87 s->context = ERR_PTR(-1); 88 mutex_init(&s->mutex); 89 tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s); 90 s->packet_index = 0; 91 92 init_waitqueue_head(&s->callback_wait); 93 s->callbacked = false; 94 95 s->fmt = fmt; 96 s->process_data_blocks = process_data_blocks; 97 98 return 0; 99 } 100 EXPORT_SYMBOL(amdtp_stream_init); 101 102 /** 103 * amdtp_stream_destroy - free stream resources 104 * @s: the AMDTP stream to destroy 105 */ 106 void amdtp_stream_destroy(struct amdtp_stream *s) 107 { 108 /* Not initialized. */ 109 if (s->protocol == NULL) 110 return; 111 112 WARN_ON(amdtp_stream_running(s)); 113 kfree(s->protocol); 114 mutex_destroy(&s->mutex); 115 } 116 EXPORT_SYMBOL(amdtp_stream_destroy); 117 118 const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = { 119 [CIP_SFC_32000] = 8, 120 [CIP_SFC_44100] = 8, 121 [CIP_SFC_48000] = 8, 122 [CIP_SFC_88200] = 16, 123 [CIP_SFC_96000] = 16, 124 [CIP_SFC_176400] = 32, 125 [CIP_SFC_192000] = 32, 126 }; 127 EXPORT_SYMBOL(amdtp_syt_intervals); 128 129 const unsigned int amdtp_rate_table[CIP_SFC_COUNT] = { 130 [CIP_SFC_32000] = 32000, 131 [CIP_SFC_44100] = 44100, 132 [CIP_SFC_48000] = 48000, 133 [CIP_SFC_88200] = 88200, 134 [CIP_SFC_96000] = 96000, 135 [CIP_SFC_176400] = 176400, 136 [CIP_SFC_192000] = 192000, 137 }; 138 EXPORT_SYMBOL(amdtp_rate_table); 139 140 /** 141 * amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream 142 * @s: the AMDTP stream, which must be initialized. 143 * @runtime: the PCM substream runtime 144 */ 145 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s, 146 struct snd_pcm_runtime *runtime) 147 { 148 int err; 149 150 /* 151 * Currently firewire-lib processes 16 packets in one software 152 * interrupt callback. This equals to 2msec but actually the 153 * interval of the interrupts has a jitter. 154 * Additionally, even if adding a constraint to fit period size to 155 * 2msec, actual calculated frames per period doesn't equal to 2msec, 156 * depending on sampling rate. 157 * Anyway, the interval to call snd_pcm_period_elapsed() cannot 2msec. 158 * Here let us use 5msec for safe period interrupt. 159 */ 160 err = snd_pcm_hw_constraint_minmax(runtime, 161 SNDRV_PCM_HW_PARAM_PERIOD_TIME, 162 5000, UINT_MAX); 163 if (err < 0) 164 goto end; 165 166 /* Non-Blocking stream has no more constraints */ 167 if (!(s->flags & CIP_BLOCKING)) 168 goto end; 169 170 /* 171 * One AMDTP packet can include some frames. In blocking mode, the 172 * number equals to SYT_INTERVAL. So the number is 8, 16 or 32, 173 * depending on its sampling rate. For accurate period interrupt, it's 174 * preferrable to align period/buffer sizes to current SYT_INTERVAL. 175 * 176 * TODO: These constraints can be improved with proper rules. 177 * Currently apply LCM of SYT_INTERVALs. 178 */ 179 err = snd_pcm_hw_constraint_step(runtime, 0, 180 SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 32); 181 if (err < 0) 182 goto end; 183 err = snd_pcm_hw_constraint_step(runtime, 0, 184 SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 32); 185 end: 186 return err; 187 } 188 EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints); 189 190 /** 191 * amdtp_stream_set_parameters - set stream parameters 192 * @s: the AMDTP stream to configure 193 * @rate: the sample rate 194 * @data_block_quadlets: the size of a data block in quadlet unit 195 * 196 * The parameters must be set before the stream is started, and must not be 197 * changed while the stream is running. 198 */ 199 int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate, 200 unsigned int data_block_quadlets) 201 { 202 unsigned int sfc; 203 204 for (sfc = 0; sfc < ARRAY_SIZE(amdtp_rate_table); ++sfc) { 205 if (amdtp_rate_table[sfc] == rate) 206 break; 207 } 208 if (sfc == ARRAY_SIZE(amdtp_rate_table)) 209 return -EINVAL; 210 211 s->sfc = sfc; 212 s->data_block_quadlets = data_block_quadlets; 213 s->syt_interval = amdtp_syt_intervals[sfc]; 214 215 /* default buffering in the device */ 216 s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE; 217 if (s->flags & CIP_BLOCKING) 218 /* additional buffering needed to adjust for no-data packets */ 219 s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate; 220 221 return 0; 222 } 223 EXPORT_SYMBOL(amdtp_stream_set_parameters); 224 225 /** 226 * amdtp_stream_get_max_payload - get the stream's packet size 227 * @s: the AMDTP stream 228 * 229 * This function must not be called before the stream has been configured 230 * with amdtp_stream_set_parameters(). 231 */ 232 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s) 233 { 234 unsigned int multiplier = 1; 235 236 if (s->flags & CIP_JUMBO_PAYLOAD) 237 multiplier = 5; 238 239 return 8 + s->syt_interval * s->data_block_quadlets * 4 * multiplier; 240 } 241 EXPORT_SYMBOL(amdtp_stream_get_max_payload); 242 243 /** 244 * amdtp_stream_pcm_prepare - prepare PCM device for running 245 * @s: the AMDTP stream 246 * 247 * This function should be called from the PCM device's .prepare callback. 248 */ 249 void amdtp_stream_pcm_prepare(struct amdtp_stream *s) 250 { 251 tasklet_kill(&s->period_tasklet); 252 s->pcm_buffer_pointer = 0; 253 s->pcm_period_pointer = 0; 254 } 255 EXPORT_SYMBOL(amdtp_stream_pcm_prepare); 256 257 static unsigned int calculate_data_blocks(struct amdtp_stream *s, 258 unsigned int syt) 259 { 260 unsigned int phase, data_blocks; 261 262 /* Blocking mode. */ 263 if (s->flags & CIP_BLOCKING) { 264 /* This module generate empty packet for 'no data'. */ 265 if (syt == CIP_SYT_NO_INFO) 266 data_blocks = 0; 267 else 268 data_blocks = s->syt_interval; 269 /* Non-blocking mode. */ 270 } else { 271 if (!cip_sfc_is_base_44100(s->sfc)) { 272 /* Sample_rate / 8000 is an integer, and precomputed. */ 273 data_blocks = s->data_block_state; 274 } else { 275 phase = s->data_block_state; 276 277 /* 278 * This calculates the number of data blocks per packet so that 279 * 1) the overall rate is correct and exactly synchronized to 280 * the bus clock, and 281 * 2) packets with a rounded-up number of blocks occur as early 282 * as possible in the sequence (to prevent underruns of the 283 * device's buffer). 284 */ 285 if (s->sfc == CIP_SFC_44100) 286 /* 6 6 5 6 5 6 5 ... */ 287 data_blocks = 5 + ((phase & 1) ^ 288 (phase == 0 || phase >= 40)); 289 else 290 /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */ 291 data_blocks = 11 * (s->sfc >> 1) + (phase == 0); 292 if (++phase >= (80 >> (s->sfc >> 1))) 293 phase = 0; 294 s->data_block_state = phase; 295 } 296 } 297 298 return data_blocks; 299 } 300 301 static unsigned int calculate_syt(struct amdtp_stream *s, 302 unsigned int cycle) 303 { 304 unsigned int syt_offset, phase, index, syt; 305 306 if (s->last_syt_offset < TICKS_PER_CYCLE) { 307 if (!cip_sfc_is_base_44100(s->sfc)) 308 syt_offset = s->last_syt_offset + s->syt_offset_state; 309 else { 310 /* 311 * The time, in ticks, of the n'th SYT_INTERVAL sample is: 312 * n * SYT_INTERVAL * 24576000 / sample_rate 313 * Modulo TICKS_PER_CYCLE, the difference between successive 314 * elements is about 1386.23. Rounding the results of this 315 * formula to the SYT precision results in a sequence of 316 * differences that begins with: 317 * 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ... 318 * This code generates _exactly_ the same sequence. 319 */ 320 phase = s->syt_offset_state; 321 index = phase % 13; 322 syt_offset = s->last_syt_offset; 323 syt_offset += 1386 + ((index && !(index & 3)) || 324 phase == 146); 325 if (++phase >= 147) 326 phase = 0; 327 s->syt_offset_state = phase; 328 } 329 } else 330 syt_offset = s->last_syt_offset - TICKS_PER_CYCLE; 331 s->last_syt_offset = syt_offset; 332 333 if (syt_offset < TICKS_PER_CYCLE) { 334 syt_offset += s->transfer_delay; 335 syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12; 336 syt += syt_offset % TICKS_PER_CYCLE; 337 338 return syt & CIP_SYT_MASK; 339 } else { 340 return CIP_SYT_NO_INFO; 341 } 342 } 343 344 static void update_pcm_pointers(struct amdtp_stream *s, 345 struct snd_pcm_substream *pcm, 346 unsigned int frames) 347 { 348 unsigned int ptr; 349 350 ptr = s->pcm_buffer_pointer + frames; 351 if (ptr >= pcm->runtime->buffer_size) 352 ptr -= pcm->runtime->buffer_size; 353 ACCESS_ONCE(s->pcm_buffer_pointer) = ptr; 354 355 s->pcm_period_pointer += frames; 356 if (s->pcm_period_pointer >= pcm->runtime->period_size) { 357 s->pcm_period_pointer -= pcm->runtime->period_size; 358 tasklet_hi_schedule(&s->period_tasklet); 359 } 360 } 361 362 static void pcm_period_tasklet(unsigned long data) 363 { 364 struct amdtp_stream *s = (void *)data; 365 struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm); 366 367 if (pcm) 368 snd_pcm_period_elapsed(pcm); 369 } 370 371 static int queue_packet(struct amdtp_stream *s, unsigned int header_length, 372 unsigned int payload_length) 373 { 374 struct fw_iso_packet p = {0}; 375 int err = 0; 376 377 if (IS_ERR(s->context)) 378 goto end; 379 380 p.interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL); 381 p.tag = TAG_CIP; 382 p.header_length = header_length; 383 if (payload_length > 0) 384 p.payload_length = payload_length; 385 else 386 p.skip = true; 387 err = fw_iso_context_queue(s->context, &p, &s->buffer.iso_buffer, 388 s->buffer.packets[s->packet_index].offset); 389 if (err < 0) { 390 dev_err(&s->unit->device, "queueing error: %d\n", err); 391 goto end; 392 } 393 394 if (++s->packet_index >= QUEUE_LENGTH) 395 s->packet_index = 0; 396 end: 397 return err; 398 } 399 400 static inline int queue_out_packet(struct amdtp_stream *s, 401 unsigned int payload_length) 402 { 403 return queue_packet(s, OUT_PACKET_HEADER_SIZE, payload_length); 404 } 405 406 static inline int queue_in_packet(struct amdtp_stream *s) 407 { 408 return queue_packet(s, IN_PACKET_HEADER_SIZE, 409 amdtp_stream_get_max_payload(s)); 410 } 411 412 static int handle_out_packet(struct amdtp_stream *s, unsigned int cycle, 413 unsigned int index) 414 { 415 __be32 *buffer; 416 unsigned int syt; 417 unsigned int data_blocks; 418 unsigned int payload_length; 419 unsigned int pcm_frames; 420 struct snd_pcm_substream *pcm; 421 422 buffer = s->buffer.packets[s->packet_index].buffer; 423 syt = calculate_syt(s, cycle); 424 data_blocks = calculate_data_blocks(s, syt); 425 pcm_frames = s->process_data_blocks(s, buffer + 2, data_blocks, &syt); 426 427 buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) | 428 (s->data_block_quadlets << CIP_DBS_SHIFT) | 429 s->data_block_counter); 430 buffer[1] = cpu_to_be32(CIP_EOH | 431 ((s->fmt << CIP_FMT_SHIFT) & CIP_FMT_MASK) | 432 ((s->fdf << CIP_FDF_SHIFT) & CIP_FDF_MASK) | 433 (syt & CIP_SYT_MASK)); 434 435 s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff; 436 payload_length = 8 + data_blocks * 4 * s->data_block_quadlets; 437 438 trace_out_packet(s, cycle, buffer, payload_length, index); 439 440 if (queue_out_packet(s, payload_length) < 0) 441 return -EIO; 442 443 pcm = ACCESS_ONCE(s->pcm); 444 if (pcm && pcm_frames > 0) 445 update_pcm_pointers(s, pcm, pcm_frames); 446 447 /* No need to return the number of handled data blocks. */ 448 return 0; 449 } 450 451 static int handle_in_packet(struct amdtp_stream *s, 452 unsigned int payload_quadlets, unsigned int cycle, 453 unsigned int index) 454 { 455 __be32 *buffer; 456 u32 cip_header[2]; 457 unsigned int fmt, fdf, syt; 458 unsigned int data_block_quadlets, data_block_counter, dbc_interval; 459 unsigned int data_blocks; 460 struct snd_pcm_substream *pcm; 461 unsigned int pcm_frames; 462 bool lost; 463 464 buffer = s->buffer.packets[s->packet_index].buffer; 465 cip_header[0] = be32_to_cpu(buffer[0]); 466 cip_header[1] = be32_to_cpu(buffer[1]); 467 468 trace_in_packet(s, cycle, cip_header, payload_quadlets, index); 469 470 /* 471 * This module supports 'Two-quadlet CIP header with SYT field'. 472 * For convenience, also check FMT field is AM824 or not. 473 */ 474 if (((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) || 475 ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH)) { 476 dev_info_ratelimited(&s->unit->device, 477 "Invalid CIP header for AMDTP: %08X:%08X\n", 478 cip_header[0], cip_header[1]); 479 data_blocks = 0; 480 pcm_frames = 0; 481 goto end; 482 } 483 484 /* Check valid protocol or not. */ 485 fmt = (cip_header[1] & CIP_FMT_MASK) >> CIP_FMT_SHIFT; 486 if (fmt != s->fmt) { 487 dev_info_ratelimited(&s->unit->device, 488 "Detect unexpected protocol: %08x %08x\n", 489 cip_header[0], cip_header[1]); 490 data_blocks = 0; 491 pcm_frames = 0; 492 goto end; 493 } 494 495 /* Calculate data blocks */ 496 fdf = (cip_header[1] & CIP_FDF_MASK) >> CIP_FDF_SHIFT; 497 if (payload_quadlets < 3 || 498 (fmt == CIP_FMT_AM && fdf == AMDTP_FDF_NO_DATA)) { 499 data_blocks = 0; 500 } else { 501 data_block_quadlets = 502 (cip_header[0] & CIP_DBS_MASK) >> CIP_DBS_SHIFT; 503 /* avoid division by zero */ 504 if (data_block_quadlets == 0) { 505 dev_err(&s->unit->device, 506 "Detect invalid value in dbs field: %08X\n", 507 cip_header[0]); 508 return -EPROTO; 509 } 510 if (s->flags & CIP_WRONG_DBS) 511 data_block_quadlets = s->data_block_quadlets; 512 513 data_blocks = (payload_quadlets - 2) / data_block_quadlets; 514 } 515 516 /* Check data block counter continuity */ 517 data_block_counter = cip_header[0] & CIP_DBC_MASK; 518 if (data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) && 519 s->data_block_counter != UINT_MAX) 520 data_block_counter = s->data_block_counter; 521 522 if (((s->flags & CIP_SKIP_DBC_ZERO_CHECK) && 523 data_block_counter == s->tx_first_dbc) || 524 s->data_block_counter == UINT_MAX) { 525 lost = false; 526 } else if (!(s->flags & CIP_DBC_IS_END_EVENT)) { 527 lost = data_block_counter != s->data_block_counter; 528 } else { 529 if (data_blocks > 0 && s->tx_dbc_interval > 0) 530 dbc_interval = s->tx_dbc_interval; 531 else 532 dbc_interval = data_blocks; 533 534 lost = data_block_counter != 535 ((s->data_block_counter + dbc_interval) & 0xff); 536 } 537 538 if (lost) { 539 dev_err(&s->unit->device, 540 "Detect discontinuity of CIP: %02X %02X\n", 541 s->data_block_counter, data_block_counter); 542 return -EIO; 543 } 544 545 syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK; 546 pcm_frames = s->process_data_blocks(s, buffer + 2, data_blocks, &syt); 547 548 if (s->flags & CIP_DBC_IS_END_EVENT) 549 s->data_block_counter = data_block_counter; 550 else 551 s->data_block_counter = 552 (data_block_counter + data_blocks) & 0xff; 553 end: 554 if (queue_in_packet(s) < 0) 555 return -EIO; 556 557 pcm = ACCESS_ONCE(s->pcm); 558 if (pcm && pcm_frames > 0) 559 update_pcm_pointers(s, pcm, pcm_frames); 560 561 return 0; 562 } 563 564 /* 565 * In CYCLE_TIMER register of IEEE 1394, 7 bits are used to represent second. On 566 * the other hand, in DMA descriptors of 1394 OHCI, 3 bits are used to represent 567 * it. Thus, via Linux firewire subsystem, we can get the 3 bits for second. 568 */ 569 static inline u32 compute_cycle_count(u32 tstamp) 570 { 571 return (((tstamp >> 13) & 0x07) * 8000) + (tstamp & 0x1fff); 572 } 573 574 static inline u32 increment_cycle_count(u32 cycle, unsigned int addend) 575 { 576 cycle += addend; 577 if (cycle >= 8 * CYCLES_PER_SECOND) 578 cycle -= 8 * CYCLES_PER_SECOND; 579 return cycle; 580 } 581 582 static inline u32 decrement_cycle_count(u32 cycle, unsigned int subtrahend) 583 { 584 if (cycle < subtrahend) 585 cycle += 8 * CYCLES_PER_SECOND; 586 return cycle - subtrahend; 587 } 588 589 static void out_stream_callback(struct fw_iso_context *context, u32 tstamp, 590 size_t header_length, void *header, 591 void *private_data) 592 { 593 struct amdtp_stream *s = private_data; 594 unsigned int i, packets = header_length / 4; 595 u32 cycle; 596 597 if (s->packet_index < 0) 598 return; 599 600 cycle = compute_cycle_count(tstamp); 601 602 /* Align to actual cycle count for the last packet. */ 603 cycle = increment_cycle_count(cycle, QUEUE_LENGTH - packets); 604 605 for (i = 0; i < packets; ++i) { 606 cycle = increment_cycle_count(cycle, 1); 607 if (handle_out_packet(s, cycle, i) < 0) { 608 s->packet_index = -1; 609 amdtp_stream_pcm_abort(s); 610 return; 611 } 612 } 613 614 fw_iso_context_queue_flush(s->context); 615 } 616 617 static void in_stream_callback(struct fw_iso_context *context, u32 tstamp, 618 size_t header_length, void *header, 619 void *private_data) 620 { 621 struct amdtp_stream *s = private_data; 622 unsigned int i, packets; 623 unsigned int payload_quadlets, max_payload_quadlets; 624 __be32 *headers = header; 625 u32 cycle; 626 627 if (s->packet_index < 0) 628 return; 629 630 /* The number of packets in buffer */ 631 packets = header_length / IN_PACKET_HEADER_SIZE; 632 633 cycle = compute_cycle_count(tstamp); 634 635 /* Align to actual cycle count for the last packet. */ 636 cycle = decrement_cycle_count(cycle, packets); 637 638 /* For buffer-over-run prevention. */ 639 max_payload_quadlets = amdtp_stream_get_max_payload(s) / 4; 640 641 for (i = 0; i < packets; i++) { 642 cycle = increment_cycle_count(cycle, 1); 643 644 /* The number of quadlets in this packet */ 645 payload_quadlets = 646 (be32_to_cpu(headers[i]) >> ISO_DATA_LENGTH_SHIFT) / 4; 647 if (payload_quadlets > max_payload_quadlets) { 648 dev_err(&s->unit->device, 649 "Detect jumbo payload: %02x %02x\n", 650 payload_quadlets, max_payload_quadlets); 651 break; 652 } 653 654 if (handle_in_packet(s, payload_quadlets, cycle, i) < 0) 655 break; 656 } 657 658 /* Queueing error or detecting invalid payload. */ 659 if (i < packets) { 660 s->packet_index = -1; 661 amdtp_stream_pcm_abort(s); 662 return; 663 } 664 665 fw_iso_context_queue_flush(s->context); 666 } 667 668 /* this is executed one time */ 669 static void amdtp_stream_first_callback(struct fw_iso_context *context, 670 u32 tstamp, size_t header_length, 671 void *header, void *private_data) 672 { 673 struct amdtp_stream *s = private_data; 674 675 /* 676 * For in-stream, first packet has come. 677 * For out-stream, prepared to transmit first packet 678 */ 679 s->callbacked = true; 680 wake_up(&s->callback_wait); 681 682 if (s->direction == AMDTP_IN_STREAM) 683 context->callback.sc = in_stream_callback; 684 else 685 context->callback.sc = out_stream_callback; 686 687 context->callback.sc(context, tstamp, header_length, header, s); 688 } 689 690 /** 691 * amdtp_stream_start - start transferring packets 692 * @s: the AMDTP stream to start 693 * @channel: the isochronous channel on the bus 694 * @speed: firewire speed code 695 * 696 * The stream cannot be started until it has been configured with 697 * amdtp_stream_set_parameters() and it must be started before any PCM or MIDI 698 * device can be started. 699 */ 700 int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed) 701 { 702 static const struct { 703 unsigned int data_block; 704 unsigned int syt_offset; 705 } initial_state[] = { 706 [CIP_SFC_32000] = { 4, 3072 }, 707 [CIP_SFC_48000] = { 6, 1024 }, 708 [CIP_SFC_96000] = { 12, 1024 }, 709 [CIP_SFC_192000] = { 24, 1024 }, 710 [CIP_SFC_44100] = { 0, 67 }, 711 [CIP_SFC_88200] = { 0, 67 }, 712 [CIP_SFC_176400] = { 0, 67 }, 713 }; 714 unsigned int header_size; 715 enum dma_data_direction dir; 716 int type, tag, err; 717 718 mutex_lock(&s->mutex); 719 720 if (WARN_ON(amdtp_stream_running(s) || 721 (s->data_block_quadlets < 1))) { 722 err = -EBADFD; 723 goto err_unlock; 724 } 725 726 if (s->direction == AMDTP_IN_STREAM) 727 s->data_block_counter = UINT_MAX; 728 else 729 s->data_block_counter = 0; 730 s->data_block_state = initial_state[s->sfc].data_block; 731 s->syt_offset_state = initial_state[s->sfc].syt_offset; 732 s->last_syt_offset = TICKS_PER_CYCLE; 733 734 /* initialize packet buffer */ 735 if (s->direction == AMDTP_IN_STREAM) { 736 dir = DMA_FROM_DEVICE; 737 type = FW_ISO_CONTEXT_RECEIVE; 738 header_size = IN_PACKET_HEADER_SIZE; 739 } else { 740 dir = DMA_TO_DEVICE; 741 type = FW_ISO_CONTEXT_TRANSMIT; 742 header_size = OUT_PACKET_HEADER_SIZE; 743 } 744 err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH, 745 amdtp_stream_get_max_payload(s), dir); 746 if (err < 0) 747 goto err_unlock; 748 749 s->context = fw_iso_context_create(fw_parent_device(s->unit)->card, 750 type, channel, speed, header_size, 751 amdtp_stream_first_callback, s); 752 if (IS_ERR(s->context)) { 753 err = PTR_ERR(s->context); 754 if (err == -EBUSY) 755 dev_err(&s->unit->device, 756 "no free stream on this controller\n"); 757 goto err_buffer; 758 } 759 760 amdtp_stream_update(s); 761 762 s->packet_index = 0; 763 do { 764 if (s->direction == AMDTP_IN_STREAM) 765 err = queue_in_packet(s); 766 else 767 err = queue_out_packet(s, 0); 768 if (err < 0) 769 goto err_context; 770 } while (s->packet_index > 0); 771 772 /* NOTE: TAG1 matches CIP. This just affects in stream. */ 773 tag = FW_ISO_CONTEXT_MATCH_TAG1; 774 if (s->flags & CIP_EMPTY_WITH_TAG0) 775 tag |= FW_ISO_CONTEXT_MATCH_TAG0; 776 777 s->callbacked = false; 778 err = fw_iso_context_start(s->context, -1, 0, tag); 779 if (err < 0) 780 goto err_context; 781 782 mutex_unlock(&s->mutex); 783 784 return 0; 785 786 err_context: 787 fw_iso_context_destroy(s->context); 788 s->context = ERR_PTR(-1); 789 err_buffer: 790 iso_packets_buffer_destroy(&s->buffer, s->unit); 791 err_unlock: 792 mutex_unlock(&s->mutex); 793 794 return err; 795 } 796 EXPORT_SYMBOL(amdtp_stream_start); 797 798 /** 799 * amdtp_stream_pcm_pointer - get the PCM buffer position 800 * @s: the AMDTP stream that transports the PCM data 801 * 802 * Returns the current buffer position, in frames. 803 */ 804 unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s) 805 { 806 /* 807 * This function is called in software IRQ context of period_tasklet or 808 * process context. 809 * 810 * When the software IRQ context was scheduled by software IRQ context 811 * of IR/IT contexts, queued packets were already handled. Therefore, 812 * no need to flush the queue in buffer anymore. 813 * 814 * When the process context reach here, some packets will be already 815 * queued in the buffer. These packets should be handled immediately 816 * to keep better granularity of PCM pointer. 817 * 818 * Later, the process context will sometimes schedules software IRQ 819 * context of the period_tasklet. Then, no need to flush the queue by 820 * the same reason as described for IR/IT contexts. 821 */ 822 if (!in_interrupt() && amdtp_stream_running(s)) 823 fw_iso_context_flush_completions(s->context); 824 825 return ACCESS_ONCE(s->pcm_buffer_pointer); 826 } 827 EXPORT_SYMBOL(amdtp_stream_pcm_pointer); 828 829 /** 830 * amdtp_stream_update - update the stream after a bus reset 831 * @s: the AMDTP stream 832 */ 833 void amdtp_stream_update(struct amdtp_stream *s) 834 { 835 /* Precomputing. */ 836 ACCESS_ONCE(s->source_node_id_field) = 837 (fw_parent_device(s->unit)->card->node_id << CIP_SID_SHIFT) & 838 CIP_SID_MASK; 839 } 840 EXPORT_SYMBOL(amdtp_stream_update); 841 842 /** 843 * amdtp_stream_stop - stop sending packets 844 * @s: the AMDTP stream to stop 845 * 846 * All PCM and MIDI devices of the stream must be stopped before the stream 847 * itself can be stopped. 848 */ 849 void amdtp_stream_stop(struct amdtp_stream *s) 850 { 851 mutex_lock(&s->mutex); 852 853 if (!amdtp_stream_running(s)) { 854 mutex_unlock(&s->mutex); 855 return; 856 } 857 858 tasklet_kill(&s->period_tasklet); 859 fw_iso_context_stop(s->context); 860 fw_iso_context_destroy(s->context); 861 s->context = ERR_PTR(-1); 862 iso_packets_buffer_destroy(&s->buffer, s->unit); 863 864 s->callbacked = false; 865 866 mutex_unlock(&s->mutex); 867 } 868 EXPORT_SYMBOL(amdtp_stream_stop); 869 870 /** 871 * amdtp_stream_pcm_abort - abort the running PCM device 872 * @s: the AMDTP stream about to be stopped 873 * 874 * If the isochronous stream needs to be stopped asynchronously, call this 875 * function first to stop the PCM device. 876 */ 877 void amdtp_stream_pcm_abort(struct amdtp_stream *s) 878 { 879 struct snd_pcm_substream *pcm; 880 881 pcm = ACCESS_ONCE(s->pcm); 882 if (pcm) 883 snd_pcm_stop_xrun(pcm); 884 } 885 EXPORT_SYMBOL(amdtp_stream_pcm_abort); 886