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_NO_CIP_HEADER 0 31 #define TAG_CIP 1 32 33 /* common isochronous packet header parameters */ 34 #define CIP_EOH_SHIFT 31 35 #define CIP_EOH (1u << CIP_EOH_SHIFT) 36 #define CIP_EOH_MASK 0x80000000 37 #define CIP_SID_SHIFT 24 38 #define CIP_SID_MASK 0x3f000000 39 #define CIP_DBS_MASK 0x00ff0000 40 #define CIP_DBS_SHIFT 16 41 #define CIP_SPH_MASK 0x00000400 42 #define CIP_SPH_SHIFT 10 43 #define CIP_DBC_MASK 0x000000ff 44 #define CIP_FMT_SHIFT 24 45 #define CIP_FMT_MASK 0x3f000000 46 #define CIP_FDF_MASK 0x00ff0000 47 #define CIP_FDF_SHIFT 16 48 #define CIP_SYT_MASK 0x0000ffff 49 #define CIP_SYT_NO_INFO 0xffff 50 51 /* Audio and Music transfer protocol specific parameters */ 52 #define CIP_FMT_AM 0x10 53 #define AMDTP_FDF_NO_DATA 0xff 54 55 /* TODO: make these configurable */ 56 #define INTERRUPT_INTERVAL 16 57 #define QUEUE_LENGTH 48 58 59 #define IN_PACKET_HEADER_SIZE 4 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 66 * @s: the AMDTP stream to initialize 67 * @unit: the target of the stream 68 * @dir: the direction of stream 69 * @flags: the packet transmission method to use 70 * @fmt: the value of fmt field in CIP header 71 * @process_data_blocks: callback handler to process data blocks 72 * @protocol_size: the size to allocate newly for protocol 73 */ 74 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit, 75 enum amdtp_stream_direction dir, enum cip_flags flags, 76 unsigned int fmt, 77 amdtp_stream_process_data_blocks_t process_data_blocks, 78 unsigned int protocol_size) 79 { 80 if (process_data_blocks == NULL) 81 return -EINVAL; 82 83 s->protocol = kzalloc(protocol_size, GFP_KERNEL); 84 if (!s->protocol) 85 return -ENOMEM; 86 87 s->unit = unit; 88 s->direction = dir; 89 s->flags = flags; 90 s->context = ERR_PTR(-1); 91 mutex_init(&s->mutex); 92 tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s); 93 s->packet_index = 0; 94 95 init_waitqueue_head(&s->callback_wait); 96 s->callbacked = false; 97 98 s->fmt = fmt; 99 s->process_data_blocks = process_data_blocks; 100 101 return 0; 102 } 103 EXPORT_SYMBOL(amdtp_stream_init); 104 105 /** 106 * amdtp_stream_destroy - free stream resources 107 * @s: the AMDTP stream to destroy 108 */ 109 void amdtp_stream_destroy(struct amdtp_stream *s) 110 { 111 /* Not initialized. */ 112 if (s->protocol == NULL) 113 return; 114 115 WARN_ON(amdtp_stream_running(s)); 116 kfree(s->protocol); 117 mutex_destroy(&s->mutex); 118 } 119 EXPORT_SYMBOL(amdtp_stream_destroy); 120 121 const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = { 122 [CIP_SFC_32000] = 8, 123 [CIP_SFC_44100] = 8, 124 [CIP_SFC_48000] = 8, 125 [CIP_SFC_88200] = 16, 126 [CIP_SFC_96000] = 16, 127 [CIP_SFC_176400] = 32, 128 [CIP_SFC_192000] = 32, 129 }; 130 EXPORT_SYMBOL(amdtp_syt_intervals); 131 132 const unsigned int amdtp_rate_table[CIP_SFC_COUNT] = { 133 [CIP_SFC_32000] = 32000, 134 [CIP_SFC_44100] = 44100, 135 [CIP_SFC_48000] = 48000, 136 [CIP_SFC_88200] = 88200, 137 [CIP_SFC_96000] = 96000, 138 [CIP_SFC_176400] = 176400, 139 [CIP_SFC_192000] = 192000, 140 }; 141 EXPORT_SYMBOL(amdtp_rate_table); 142 143 /** 144 * amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream 145 * @s: the AMDTP stream, which must be initialized. 146 * @runtime: the PCM substream runtime 147 */ 148 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s, 149 struct snd_pcm_runtime *runtime) 150 { 151 struct snd_pcm_hardware *hw = &runtime->hw; 152 int err; 153 154 hw->info = SNDRV_PCM_INFO_BATCH | 155 SNDRV_PCM_INFO_BLOCK_TRANSFER | 156 SNDRV_PCM_INFO_INTERLEAVED | 157 SNDRV_PCM_INFO_JOINT_DUPLEX | 158 SNDRV_PCM_INFO_MMAP | 159 SNDRV_PCM_INFO_MMAP_VALID; 160 161 /* SNDRV_PCM_INFO_BATCH */ 162 hw->periods_min = 2; 163 hw->periods_max = UINT_MAX; 164 165 /* bytes for a frame */ 166 hw->period_bytes_min = 4 * hw->channels_max; 167 168 /* Just to prevent from allocating much pages. */ 169 hw->period_bytes_max = hw->period_bytes_min * 2048; 170 hw->buffer_bytes_max = hw->period_bytes_max * hw->periods_min; 171 172 /* 173 * Currently firewire-lib processes 16 packets in one software 174 * interrupt callback. This equals to 2msec but actually the 175 * interval of the interrupts has a jitter. 176 * Additionally, even if adding a constraint to fit period size to 177 * 2msec, actual calculated frames per period doesn't equal to 2msec, 178 * depending on sampling rate. 179 * Anyway, the interval to call snd_pcm_period_elapsed() cannot 2msec. 180 * Here let us use 5msec for safe period interrupt. 181 */ 182 err = snd_pcm_hw_constraint_minmax(runtime, 183 SNDRV_PCM_HW_PARAM_PERIOD_TIME, 184 5000, UINT_MAX); 185 if (err < 0) 186 goto end; 187 188 /* Non-Blocking stream has no more constraints */ 189 if (!(s->flags & CIP_BLOCKING)) 190 goto end; 191 192 /* 193 * One AMDTP packet can include some frames. In blocking mode, the 194 * number equals to SYT_INTERVAL. So the number is 8, 16 or 32, 195 * depending on its sampling rate. For accurate period interrupt, it's 196 * preferrable to align period/buffer sizes to current SYT_INTERVAL. 197 * 198 * TODO: These constraints can be improved with proper rules. 199 * Currently apply LCM of SYT_INTERVALs. 200 */ 201 err = snd_pcm_hw_constraint_step(runtime, 0, 202 SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 32); 203 if (err < 0) 204 goto end; 205 err = snd_pcm_hw_constraint_step(runtime, 0, 206 SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 32); 207 end: 208 return err; 209 } 210 EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints); 211 212 /** 213 * amdtp_stream_set_parameters - set stream parameters 214 * @s: the AMDTP stream to configure 215 * @rate: the sample rate 216 * @data_block_quadlets: the size of a data block in quadlet unit 217 * 218 * The parameters must be set before the stream is started, and must not be 219 * changed while the stream is running. 220 */ 221 int amdtp_stream_set_parameters(struct amdtp_stream *s, unsigned int rate, 222 unsigned int data_block_quadlets) 223 { 224 unsigned int sfc; 225 226 for (sfc = 0; sfc < ARRAY_SIZE(amdtp_rate_table); ++sfc) { 227 if (amdtp_rate_table[sfc] == rate) 228 break; 229 } 230 if (sfc == ARRAY_SIZE(amdtp_rate_table)) 231 return -EINVAL; 232 233 s->sfc = sfc; 234 s->data_block_quadlets = data_block_quadlets; 235 s->syt_interval = amdtp_syt_intervals[sfc]; 236 237 /* default buffering in the device */ 238 s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE; 239 if (s->flags & CIP_BLOCKING) 240 /* additional buffering needed to adjust for no-data packets */ 241 s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate; 242 243 return 0; 244 } 245 EXPORT_SYMBOL(amdtp_stream_set_parameters); 246 247 /** 248 * amdtp_stream_get_max_payload - get the stream's packet size 249 * @s: the AMDTP stream 250 * 251 * This function must not be called before the stream has been configured 252 * with amdtp_stream_set_parameters(). 253 */ 254 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s) 255 { 256 unsigned int multiplier = 1; 257 unsigned int header_size = 0; 258 259 if (s->flags & CIP_JUMBO_PAYLOAD) 260 multiplier = 5; 261 if (!(s->flags & CIP_NO_HEADER)) 262 header_size = 8; 263 264 return header_size + 265 s->syt_interval * s->data_block_quadlets * 4 * multiplier; 266 } 267 EXPORT_SYMBOL(amdtp_stream_get_max_payload); 268 269 /** 270 * amdtp_stream_pcm_prepare - prepare PCM device for running 271 * @s: the AMDTP stream 272 * 273 * This function should be called from the PCM device's .prepare callback. 274 */ 275 void amdtp_stream_pcm_prepare(struct amdtp_stream *s) 276 { 277 tasklet_kill(&s->period_tasklet); 278 s->pcm_buffer_pointer = 0; 279 s->pcm_period_pointer = 0; 280 } 281 EXPORT_SYMBOL(amdtp_stream_pcm_prepare); 282 283 static unsigned int calculate_data_blocks(struct amdtp_stream *s, 284 unsigned int syt) 285 { 286 unsigned int phase, data_blocks; 287 288 /* Blocking mode. */ 289 if (s->flags & CIP_BLOCKING) { 290 /* This module generate empty packet for 'no data'. */ 291 if (syt == CIP_SYT_NO_INFO) 292 data_blocks = 0; 293 else 294 data_blocks = s->syt_interval; 295 /* Non-blocking mode. */ 296 } else { 297 if (!cip_sfc_is_base_44100(s->sfc)) { 298 /* Sample_rate / 8000 is an integer, and precomputed. */ 299 data_blocks = s->data_block_state; 300 } else { 301 phase = s->data_block_state; 302 303 /* 304 * This calculates the number of data blocks per packet so that 305 * 1) the overall rate is correct and exactly synchronized to 306 * the bus clock, and 307 * 2) packets with a rounded-up number of blocks occur as early 308 * as possible in the sequence (to prevent underruns of the 309 * device's buffer). 310 */ 311 if (s->sfc == CIP_SFC_44100) 312 /* 6 6 5 6 5 6 5 ... */ 313 data_blocks = 5 + ((phase & 1) ^ 314 (phase == 0 || phase >= 40)); 315 else 316 /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */ 317 data_blocks = 11 * (s->sfc >> 1) + (phase == 0); 318 if (++phase >= (80 >> (s->sfc >> 1))) 319 phase = 0; 320 s->data_block_state = phase; 321 } 322 } 323 324 return data_blocks; 325 } 326 327 static unsigned int calculate_syt(struct amdtp_stream *s, 328 unsigned int cycle) 329 { 330 unsigned int syt_offset, phase, index, syt; 331 332 if (s->last_syt_offset < TICKS_PER_CYCLE) { 333 if (!cip_sfc_is_base_44100(s->sfc)) 334 syt_offset = s->last_syt_offset + s->syt_offset_state; 335 else { 336 /* 337 * The time, in ticks, of the n'th SYT_INTERVAL sample is: 338 * n * SYT_INTERVAL * 24576000 / sample_rate 339 * Modulo TICKS_PER_CYCLE, the difference between successive 340 * elements is about 1386.23. Rounding the results of this 341 * formula to the SYT precision results in a sequence of 342 * differences that begins with: 343 * 1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ... 344 * This code generates _exactly_ the same sequence. 345 */ 346 phase = s->syt_offset_state; 347 index = phase % 13; 348 syt_offset = s->last_syt_offset; 349 syt_offset += 1386 + ((index && !(index & 3)) || 350 phase == 146); 351 if (++phase >= 147) 352 phase = 0; 353 s->syt_offset_state = phase; 354 } 355 } else 356 syt_offset = s->last_syt_offset - TICKS_PER_CYCLE; 357 s->last_syt_offset = syt_offset; 358 359 if (syt_offset < TICKS_PER_CYCLE) { 360 syt_offset += s->transfer_delay; 361 syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12; 362 syt += syt_offset % TICKS_PER_CYCLE; 363 364 return syt & CIP_SYT_MASK; 365 } else { 366 return CIP_SYT_NO_INFO; 367 } 368 } 369 370 static void update_pcm_pointers(struct amdtp_stream *s, 371 struct snd_pcm_substream *pcm, 372 unsigned int frames) 373 { 374 unsigned int ptr; 375 376 ptr = s->pcm_buffer_pointer + frames; 377 if (ptr >= pcm->runtime->buffer_size) 378 ptr -= pcm->runtime->buffer_size; 379 WRITE_ONCE(s->pcm_buffer_pointer, ptr); 380 381 s->pcm_period_pointer += frames; 382 if (s->pcm_period_pointer >= pcm->runtime->period_size) { 383 s->pcm_period_pointer -= pcm->runtime->period_size; 384 tasklet_hi_schedule(&s->period_tasklet); 385 } 386 } 387 388 static void pcm_period_tasklet(unsigned long data) 389 { 390 struct amdtp_stream *s = (void *)data; 391 struct snd_pcm_substream *pcm = READ_ONCE(s->pcm); 392 393 if (pcm) 394 snd_pcm_period_elapsed(pcm); 395 } 396 397 static int queue_packet(struct amdtp_stream *s, unsigned int header_length, 398 unsigned int payload_length) 399 { 400 struct fw_iso_packet p = {0}; 401 int err = 0; 402 403 if (IS_ERR(s->context)) 404 goto end; 405 406 p.interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL); 407 p.tag = s->tag; 408 p.header_length = header_length; 409 if (payload_length > 0) 410 p.payload_length = payload_length; 411 else 412 p.skip = true; 413 err = fw_iso_context_queue(s->context, &p, &s->buffer.iso_buffer, 414 s->buffer.packets[s->packet_index].offset); 415 if (err < 0) { 416 dev_err(&s->unit->device, "queueing error: %d\n", err); 417 goto end; 418 } 419 420 if (++s->packet_index >= QUEUE_LENGTH) 421 s->packet_index = 0; 422 end: 423 return err; 424 } 425 426 static inline int queue_out_packet(struct amdtp_stream *s, 427 unsigned int payload_length) 428 { 429 return queue_packet(s, OUT_PACKET_HEADER_SIZE, payload_length); 430 } 431 432 static inline int queue_in_packet(struct amdtp_stream *s) 433 { 434 return queue_packet(s, IN_PACKET_HEADER_SIZE, s->max_payload_length); 435 } 436 437 static int handle_out_packet(struct amdtp_stream *s, 438 unsigned int payload_length, unsigned int cycle, 439 unsigned int index) 440 { 441 __be32 *buffer; 442 unsigned int syt; 443 unsigned int data_blocks; 444 unsigned int pcm_frames; 445 struct snd_pcm_substream *pcm; 446 447 buffer = s->buffer.packets[s->packet_index].buffer; 448 syt = calculate_syt(s, cycle); 449 data_blocks = calculate_data_blocks(s, syt); 450 pcm_frames = s->process_data_blocks(s, buffer + 2, data_blocks, &syt); 451 452 if (s->flags & CIP_DBC_IS_END_EVENT) 453 s->data_block_counter = 454 (s->data_block_counter + data_blocks) & 0xff; 455 456 buffer[0] = cpu_to_be32(READ_ONCE(s->source_node_id_field) | 457 (s->data_block_quadlets << CIP_DBS_SHIFT) | 458 ((s->sph << CIP_SPH_SHIFT) & CIP_SPH_MASK) | 459 s->data_block_counter); 460 buffer[1] = cpu_to_be32(CIP_EOH | 461 ((s->fmt << CIP_FMT_SHIFT) & CIP_FMT_MASK) | 462 ((s->fdf << CIP_FDF_SHIFT) & CIP_FDF_MASK) | 463 (syt & CIP_SYT_MASK)); 464 465 if (!(s->flags & CIP_DBC_IS_END_EVENT)) 466 s->data_block_counter = 467 (s->data_block_counter + data_blocks) & 0xff; 468 payload_length = 8 + data_blocks * 4 * s->data_block_quadlets; 469 470 trace_out_packet(s, cycle, buffer, payload_length, index); 471 472 if (queue_out_packet(s, payload_length) < 0) 473 return -EIO; 474 475 pcm = READ_ONCE(s->pcm); 476 if (pcm && pcm_frames > 0) 477 update_pcm_pointers(s, pcm, pcm_frames); 478 479 /* No need to return the number of handled data blocks. */ 480 return 0; 481 } 482 483 static int handle_out_packet_without_header(struct amdtp_stream *s, 484 unsigned int payload_length, unsigned int cycle, 485 unsigned int index) 486 { 487 __be32 *buffer; 488 unsigned int syt; 489 unsigned int data_blocks; 490 unsigned int pcm_frames; 491 struct snd_pcm_substream *pcm; 492 493 buffer = s->buffer.packets[s->packet_index].buffer; 494 syt = calculate_syt(s, cycle); 495 data_blocks = calculate_data_blocks(s, syt); 496 pcm_frames = s->process_data_blocks(s, buffer, data_blocks, &syt); 497 s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff; 498 499 payload_length = data_blocks * 4 * s->data_block_quadlets; 500 501 trace_out_packet_without_header(s, cycle, payload_length, data_blocks, 502 index); 503 504 if (queue_out_packet(s, payload_length) < 0) 505 return -EIO; 506 507 pcm = READ_ONCE(s->pcm); 508 if (pcm && pcm_frames > 0) 509 update_pcm_pointers(s, pcm, pcm_frames); 510 511 /* No need to return the number of handled data blocks. */ 512 return 0; 513 } 514 515 static int handle_in_packet(struct amdtp_stream *s, 516 unsigned int payload_length, unsigned int cycle, 517 unsigned int index) 518 { 519 __be32 *buffer; 520 u32 cip_header[2]; 521 unsigned int sph, fmt, fdf, syt; 522 unsigned int data_block_quadlets, data_block_counter, dbc_interval; 523 unsigned int data_blocks; 524 struct snd_pcm_substream *pcm; 525 unsigned int pcm_frames; 526 bool lost; 527 528 buffer = s->buffer.packets[s->packet_index].buffer; 529 cip_header[0] = be32_to_cpu(buffer[0]); 530 cip_header[1] = be32_to_cpu(buffer[1]); 531 532 trace_in_packet(s, cycle, cip_header, payload_length, index); 533 534 /* 535 * This module supports 'Two-quadlet CIP header with SYT field'. 536 * For convenience, also check FMT field is AM824 or not. 537 */ 538 if ((((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) || 539 ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH)) && 540 (!(s->flags & CIP_HEADER_WITHOUT_EOH))) { 541 dev_info_ratelimited(&s->unit->device, 542 "Invalid CIP header for AMDTP: %08X:%08X\n", 543 cip_header[0], cip_header[1]); 544 data_blocks = 0; 545 pcm_frames = 0; 546 goto end; 547 } 548 549 /* Check valid protocol or not. */ 550 sph = (cip_header[0] & CIP_SPH_MASK) >> CIP_SPH_SHIFT; 551 fmt = (cip_header[1] & CIP_FMT_MASK) >> CIP_FMT_SHIFT; 552 if (sph != s->sph || fmt != s->fmt) { 553 dev_info_ratelimited(&s->unit->device, 554 "Detect unexpected protocol: %08x %08x\n", 555 cip_header[0], cip_header[1]); 556 data_blocks = 0; 557 pcm_frames = 0; 558 goto end; 559 } 560 561 /* Calculate data blocks */ 562 fdf = (cip_header[1] & CIP_FDF_MASK) >> CIP_FDF_SHIFT; 563 if (payload_length < 12 || 564 (fmt == CIP_FMT_AM && fdf == AMDTP_FDF_NO_DATA)) { 565 data_blocks = 0; 566 } else { 567 data_block_quadlets = 568 (cip_header[0] & CIP_DBS_MASK) >> CIP_DBS_SHIFT; 569 /* avoid division by zero */ 570 if (data_block_quadlets == 0) { 571 dev_err(&s->unit->device, 572 "Detect invalid value in dbs field: %08X\n", 573 cip_header[0]); 574 return -EPROTO; 575 } 576 if (s->flags & CIP_WRONG_DBS) 577 data_block_quadlets = s->data_block_quadlets; 578 579 data_blocks = (payload_length / 4 - 2) / 580 data_block_quadlets; 581 } 582 583 /* Check data block counter continuity */ 584 data_block_counter = cip_header[0] & CIP_DBC_MASK; 585 if (data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) && 586 s->data_block_counter != UINT_MAX) 587 data_block_counter = s->data_block_counter; 588 589 if (((s->flags & CIP_SKIP_DBC_ZERO_CHECK) && 590 data_block_counter == s->tx_first_dbc) || 591 s->data_block_counter == UINT_MAX) { 592 lost = false; 593 } else if (!(s->flags & CIP_DBC_IS_END_EVENT)) { 594 lost = data_block_counter != s->data_block_counter; 595 } else { 596 if (data_blocks > 0 && s->tx_dbc_interval > 0) 597 dbc_interval = s->tx_dbc_interval; 598 else 599 dbc_interval = data_blocks; 600 601 lost = data_block_counter != 602 ((s->data_block_counter + dbc_interval) & 0xff); 603 } 604 605 if (lost) { 606 dev_err(&s->unit->device, 607 "Detect discontinuity of CIP: %02X %02X\n", 608 s->data_block_counter, data_block_counter); 609 return -EIO; 610 } 611 612 syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK; 613 pcm_frames = s->process_data_blocks(s, buffer + 2, data_blocks, &syt); 614 615 if (s->flags & CIP_DBC_IS_END_EVENT) 616 s->data_block_counter = data_block_counter; 617 else 618 s->data_block_counter = 619 (data_block_counter + data_blocks) & 0xff; 620 end: 621 if (queue_in_packet(s) < 0) 622 return -EIO; 623 624 pcm = READ_ONCE(s->pcm); 625 if (pcm && pcm_frames > 0) 626 update_pcm_pointers(s, pcm, pcm_frames); 627 628 return 0; 629 } 630 631 static int handle_in_packet_without_header(struct amdtp_stream *s, 632 unsigned int payload_quadlets, unsigned int cycle, 633 unsigned int index) 634 { 635 __be32 *buffer; 636 unsigned int data_blocks; 637 struct snd_pcm_substream *pcm; 638 unsigned int pcm_frames; 639 640 buffer = s->buffer.packets[s->packet_index].buffer; 641 data_blocks = payload_quadlets / s->data_block_quadlets; 642 643 trace_in_packet_without_header(s, cycle, payload_quadlets, data_blocks, 644 index); 645 646 pcm_frames = s->process_data_blocks(s, buffer, data_blocks, NULL); 647 s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff; 648 649 if (queue_in_packet(s) < 0) 650 return -EIO; 651 652 pcm = READ_ONCE(s->pcm); 653 if (pcm && pcm_frames > 0) 654 update_pcm_pointers(s, pcm, pcm_frames); 655 656 return 0; 657 } 658 659 /* 660 * In CYCLE_TIMER register of IEEE 1394, 7 bits are used to represent second. On 661 * the other hand, in DMA descriptors of 1394 OHCI, 3 bits are used to represent 662 * it. Thus, via Linux firewire subsystem, we can get the 3 bits for second. 663 */ 664 static inline u32 compute_cycle_count(u32 tstamp) 665 { 666 return (((tstamp >> 13) & 0x07) * 8000) + (tstamp & 0x1fff); 667 } 668 669 static inline u32 increment_cycle_count(u32 cycle, unsigned int addend) 670 { 671 cycle += addend; 672 if (cycle >= 8 * CYCLES_PER_SECOND) 673 cycle -= 8 * CYCLES_PER_SECOND; 674 return cycle; 675 } 676 677 static inline u32 decrement_cycle_count(u32 cycle, unsigned int subtrahend) 678 { 679 if (cycle < subtrahend) 680 cycle += 8 * CYCLES_PER_SECOND; 681 return cycle - subtrahend; 682 } 683 684 static void out_stream_callback(struct fw_iso_context *context, u32 tstamp, 685 size_t header_length, void *header, 686 void *private_data) 687 { 688 struct amdtp_stream *s = private_data; 689 unsigned int i, packets = header_length / 4; 690 u32 cycle; 691 692 if (s->packet_index < 0) 693 return; 694 695 cycle = compute_cycle_count(tstamp); 696 697 /* Align to actual cycle count for the last packet. */ 698 cycle = increment_cycle_count(cycle, QUEUE_LENGTH - packets); 699 700 for (i = 0; i < packets; ++i) { 701 cycle = increment_cycle_count(cycle, 1); 702 if (s->handle_packet(s, 0, cycle, i) < 0) { 703 s->packet_index = -1; 704 if (in_interrupt()) 705 amdtp_stream_pcm_abort(s); 706 WRITE_ONCE(s->pcm_buffer_pointer, SNDRV_PCM_POS_XRUN); 707 return; 708 } 709 } 710 711 fw_iso_context_queue_flush(s->context); 712 } 713 714 static void in_stream_callback(struct fw_iso_context *context, u32 tstamp, 715 size_t header_length, void *header, 716 void *private_data) 717 { 718 struct amdtp_stream *s = private_data; 719 unsigned int i, packets; 720 unsigned int payload_length, max_payload_length; 721 __be32 *headers = header; 722 u32 cycle; 723 724 if (s->packet_index < 0) 725 return; 726 727 /* The number of packets in buffer */ 728 packets = header_length / IN_PACKET_HEADER_SIZE; 729 730 cycle = compute_cycle_count(tstamp); 731 732 /* Align to actual cycle count for the last packet. */ 733 cycle = decrement_cycle_count(cycle, packets); 734 735 /* For buffer-over-run prevention. */ 736 max_payload_length = s->max_payload_length; 737 738 for (i = 0; i < packets; i++) { 739 cycle = increment_cycle_count(cycle, 1); 740 741 /* The number of bytes in this packet */ 742 payload_length = 743 (be32_to_cpu(headers[i]) >> ISO_DATA_LENGTH_SHIFT); 744 if (payload_length > max_payload_length) { 745 dev_err(&s->unit->device, 746 "Detect jumbo payload: %04x %04x\n", 747 payload_length, max_payload_length); 748 break; 749 } 750 751 if (s->handle_packet(s, payload_length, cycle, i) < 0) 752 break; 753 } 754 755 /* Queueing error or detecting invalid payload. */ 756 if (i < packets) { 757 s->packet_index = -1; 758 if (in_interrupt()) 759 amdtp_stream_pcm_abort(s); 760 WRITE_ONCE(s->pcm_buffer_pointer, SNDRV_PCM_POS_XRUN); 761 return; 762 } 763 764 fw_iso_context_queue_flush(s->context); 765 } 766 767 /* this is executed one time */ 768 static void amdtp_stream_first_callback(struct fw_iso_context *context, 769 u32 tstamp, size_t header_length, 770 void *header, void *private_data) 771 { 772 struct amdtp_stream *s = private_data; 773 u32 cycle; 774 unsigned int packets; 775 776 s->max_payload_length = amdtp_stream_get_max_payload(s); 777 778 /* 779 * For in-stream, first packet has come. 780 * For out-stream, prepared to transmit first packet 781 */ 782 s->callbacked = true; 783 wake_up(&s->callback_wait); 784 785 cycle = compute_cycle_count(tstamp); 786 787 if (s->direction == AMDTP_IN_STREAM) { 788 packets = header_length / IN_PACKET_HEADER_SIZE; 789 cycle = decrement_cycle_count(cycle, packets); 790 context->callback.sc = in_stream_callback; 791 if (s->flags & CIP_NO_HEADER) 792 s->handle_packet = handle_in_packet_without_header; 793 else 794 s->handle_packet = handle_in_packet; 795 } else { 796 packets = header_length / 4; 797 cycle = increment_cycle_count(cycle, QUEUE_LENGTH - packets); 798 context->callback.sc = out_stream_callback; 799 if (s->flags & CIP_NO_HEADER) 800 s->handle_packet = handle_out_packet_without_header; 801 else 802 s->handle_packet = handle_out_packet; 803 } 804 805 s->start_cycle = cycle; 806 807 context->callback.sc(context, tstamp, header_length, header, s); 808 } 809 810 /** 811 * amdtp_stream_start - start transferring packets 812 * @s: the AMDTP stream to start 813 * @channel: the isochronous channel on the bus 814 * @speed: firewire speed code 815 * 816 * The stream cannot be started until it has been configured with 817 * amdtp_stream_set_parameters() and it must be started before any PCM or MIDI 818 * device can be started. 819 */ 820 int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed) 821 { 822 static const struct { 823 unsigned int data_block; 824 unsigned int syt_offset; 825 } initial_state[] = { 826 [CIP_SFC_32000] = { 4, 3072 }, 827 [CIP_SFC_48000] = { 6, 1024 }, 828 [CIP_SFC_96000] = { 12, 1024 }, 829 [CIP_SFC_192000] = { 24, 1024 }, 830 [CIP_SFC_44100] = { 0, 67 }, 831 [CIP_SFC_88200] = { 0, 67 }, 832 [CIP_SFC_176400] = { 0, 67 }, 833 }; 834 unsigned int header_size; 835 enum dma_data_direction dir; 836 int type, tag, err; 837 838 mutex_lock(&s->mutex); 839 840 if (WARN_ON(amdtp_stream_running(s) || 841 (s->data_block_quadlets < 1))) { 842 err = -EBADFD; 843 goto err_unlock; 844 } 845 846 if (s->direction == AMDTP_IN_STREAM) 847 s->data_block_counter = UINT_MAX; 848 else 849 s->data_block_counter = 0; 850 s->data_block_state = initial_state[s->sfc].data_block; 851 s->syt_offset_state = initial_state[s->sfc].syt_offset; 852 s->last_syt_offset = TICKS_PER_CYCLE; 853 854 /* initialize packet buffer */ 855 if (s->direction == AMDTP_IN_STREAM) { 856 dir = DMA_FROM_DEVICE; 857 type = FW_ISO_CONTEXT_RECEIVE; 858 header_size = IN_PACKET_HEADER_SIZE; 859 } else { 860 dir = DMA_TO_DEVICE; 861 type = FW_ISO_CONTEXT_TRANSMIT; 862 header_size = OUT_PACKET_HEADER_SIZE; 863 } 864 err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH, 865 amdtp_stream_get_max_payload(s), dir); 866 if (err < 0) 867 goto err_unlock; 868 869 s->context = fw_iso_context_create(fw_parent_device(s->unit)->card, 870 type, channel, speed, header_size, 871 amdtp_stream_first_callback, s); 872 if (IS_ERR(s->context)) { 873 err = PTR_ERR(s->context); 874 if (err == -EBUSY) 875 dev_err(&s->unit->device, 876 "no free stream on this controller\n"); 877 goto err_buffer; 878 } 879 880 amdtp_stream_update(s); 881 882 if (s->flags & CIP_NO_HEADER) 883 s->tag = TAG_NO_CIP_HEADER; 884 else 885 s->tag = TAG_CIP; 886 887 s->packet_index = 0; 888 do { 889 if (s->direction == AMDTP_IN_STREAM) 890 err = queue_in_packet(s); 891 else 892 err = queue_out_packet(s, 0); 893 if (err < 0) 894 goto err_context; 895 } while (s->packet_index > 0); 896 897 /* NOTE: TAG1 matches CIP. This just affects in stream. */ 898 tag = FW_ISO_CONTEXT_MATCH_TAG1; 899 if ((s->flags & CIP_EMPTY_WITH_TAG0) || (s->flags & CIP_NO_HEADER)) 900 tag |= FW_ISO_CONTEXT_MATCH_TAG0; 901 902 s->callbacked = false; 903 err = fw_iso_context_start(s->context, -1, 0, tag); 904 if (err < 0) 905 goto err_context; 906 907 mutex_unlock(&s->mutex); 908 909 return 0; 910 911 err_context: 912 fw_iso_context_destroy(s->context); 913 s->context = ERR_PTR(-1); 914 err_buffer: 915 iso_packets_buffer_destroy(&s->buffer, s->unit); 916 err_unlock: 917 mutex_unlock(&s->mutex); 918 919 return err; 920 } 921 EXPORT_SYMBOL(amdtp_stream_start); 922 923 /** 924 * amdtp_stream_pcm_pointer - get the PCM buffer position 925 * @s: the AMDTP stream that transports the PCM data 926 * 927 * Returns the current buffer position, in frames. 928 */ 929 unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s) 930 { 931 /* 932 * This function is called in software IRQ context of period_tasklet or 933 * process context. 934 * 935 * When the software IRQ context was scheduled by software IRQ context 936 * of IR/IT contexts, queued packets were already handled. Therefore, 937 * no need to flush the queue in buffer anymore. 938 * 939 * When the process context reach here, some packets will be already 940 * queued in the buffer. These packets should be handled immediately 941 * to keep better granularity of PCM pointer. 942 * 943 * Later, the process context will sometimes schedules software IRQ 944 * context of the period_tasklet. Then, no need to flush the queue by 945 * the same reason as described for IR/IT contexts. 946 */ 947 if (!in_interrupt() && amdtp_stream_running(s)) 948 fw_iso_context_flush_completions(s->context); 949 950 return READ_ONCE(s->pcm_buffer_pointer); 951 } 952 EXPORT_SYMBOL(amdtp_stream_pcm_pointer); 953 954 /** 955 * amdtp_stream_pcm_ack - acknowledge queued PCM frames 956 * @s: the AMDTP stream that transfers the PCM frames 957 * 958 * Returns zero always. 959 */ 960 int amdtp_stream_pcm_ack(struct amdtp_stream *s) 961 { 962 /* 963 * Process isochronous packets for recent isochronous cycle to handle 964 * queued PCM frames. 965 */ 966 if (amdtp_stream_running(s)) 967 fw_iso_context_flush_completions(s->context); 968 969 return 0; 970 } 971 EXPORT_SYMBOL(amdtp_stream_pcm_ack); 972 973 /** 974 * amdtp_stream_update - update the stream after a bus reset 975 * @s: the AMDTP stream 976 */ 977 void amdtp_stream_update(struct amdtp_stream *s) 978 { 979 /* Precomputing. */ 980 WRITE_ONCE(s->source_node_id_field, 981 (fw_parent_device(s->unit)->card->node_id << CIP_SID_SHIFT) & CIP_SID_MASK); 982 } 983 EXPORT_SYMBOL(amdtp_stream_update); 984 985 /** 986 * amdtp_stream_stop - stop sending packets 987 * @s: the AMDTP stream to stop 988 * 989 * All PCM and MIDI devices of the stream must be stopped before the stream 990 * itself can be stopped. 991 */ 992 void amdtp_stream_stop(struct amdtp_stream *s) 993 { 994 mutex_lock(&s->mutex); 995 996 if (!amdtp_stream_running(s)) { 997 mutex_unlock(&s->mutex); 998 return; 999 } 1000 1001 tasklet_kill(&s->period_tasklet); 1002 fw_iso_context_stop(s->context); 1003 fw_iso_context_destroy(s->context); 1004 s->context = ERR_PTR(-1); 1005 iso_packets_buffer_destroy(&s->buffer, s->unit); 1006 1007 s->callbacked = false; 1008 1009 mutex_unlock(&s->mutex); 1010 } 1011 EXPORT_SYMBOL(amdtp_stream_stop); 1012 1013 /** 1014 * amdtp_stream_pcm_abort - abort the running PCM device 1015 * @s: the AMDTP stream about to be stopped 1016 * 1017 * If the isochronous stream needs to be stopped asynchronously, call this 1018 * function first to stop the PCM device. 1019 */ 1020 void amdtp_stream_pcm_abort(struct amdtp_stream *s) 1021 { 1022 struct snd_pcm_substream *pcm; 1023 1024 pcm = READ_ONCE(s->pcm); 1025 if (pcm) 1026 snd_pcm_stop_xrun(pcm); 1027 } 1028 EXPORT_SYMBOL(amdtp_stream_pcm_abort); 1029