sound/firewire/amdtp.c

   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 <linux/sched.h>
  15 #include <sound/pcm.h>
  16 #include <sound/pcm_params.h>
  17 #include <sound/rawmidi.h>
  18 #include "amdtp.h"
  19
  20 #define TICKS_PER_CYCLE         3072
  21 #define CYCLES_PER_SECOND       8000
  22 #define TICKS_PER_SECOND        (TICKS_PER_CYCLE * CYCLES_PER_SECOND)
  23
  24 #define TRANSFER_DELAY_TICKS    0x2e00 /* 479.17 µs */
  25
  26 /* isochronous header parameters */
  27 #define ISO_DATA_LENGTH_SHIFT   16
  28 #define TAG_CIP                 1
  29
  30 /* common isochronous packet header parameters */
  31 #define CIP_EOH                 (1u << 31)
  32 #define CIP_EOH_MASK            0x80000000
  33 #define CIP_FMT_AM              (0x10 << 24)
  34 #define CIP_FMT_MASK            0x3f000000
  35 #define CIP_SYT_MASK            0x0000ffff
  36 #define CIP_SYT_NO_INFO         0xffff
  37 #define CIP_FDF_MASK            0x00ff0000
  38 #define CIP_FDF_SFC_SHIFT       16
  39
  40 /*
  41  * Audio and Music transfer protocol specific parameters
  42  * only "Clock-based rate control mode" is supported
  43  */
  44 #define AMDTP_FDF_AM824         (0 << (CIP_FDF_SFC_SHIFT + 3))
  45 #define AMDTP_FDF_NO_DATA       0xff
  46 #define AMDTP_DBS_MASK          0x00ff0000
  47 #define AMDTP_DBS_SHIFT         16
  48 #define AMDTP_DBC_MASK          0x000000ff
  49
  50 /* TODO: make these configurable */
  51 #define INTERRUPT_INTERVAL      16
  52 #define QUEUE_LENGTH            48
  53
  54 #define IN_PACKET_HEADER_SIZE   4
  55 #define OUT_PACKET_HEADER_SIZE  0
  56
  57 static void pcm_period_tasklet(unsigned long data);
  58
  59 /**
  60  * amdtp_stream_init - initialize an AMDTP stream structure
  61  * @s: the AMDTP stream to initialize
  62  * @unit: the target of the stream
  63  * @dir: the direction of stream
  64  * @flags: the packet transmission method to use
  65  */
  66 int amdtp_stream_init(struct amdtp_stream *s, struct fw_unit *unit,
  67                       enum amdtp_stream_direction dir, enum cip_flags flags)
  68 {
  69         s->unit = fw_unit_get(unit);
  70         s->direction = dir;
  71         s->flags = flags;
  72         s->context = ERR_PTR(-1);
  73         mutex_init(&s->mutex);
  74         tasklet_init(&s->period_tasklet, pcm_period_tasklet, (unsigned long)s);
  75         s->packet_index = 0;
  76
  77         init_waitqueue_head(&s->callback_wait);
  78         s->callbacked = false;
  79         s->sync_slave = NULL;
  80
  81         return 0;
  82 }
  83 EXPORT_SYMBOL(amdtp_stream_init);
  84
  85 /**
  86  * amdtp_stream_destroy - free stream resources
  87  * @s: the AMDTP stream to destroy
  88  */
  89 void amdtp_stream_destroy(struct amdtp_stream *s)
  90 {
  91         WARN_ON(amdtp_stream_running(s));
  92         mutex_destroy(&s->mutex);
  93         fw_unit_put(s->unit);
  94 }
  95 EXPORT_SYMBOL(amdtp_stream_destroy);
  96
  97 const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = {
  98         [CIP_SFC_32000]  =  8,
  99         [CIP_SFC_44100]  =  8,
 100         [CIP_SFC_48000]  =  8,
 101         [CIP_SFC_88200]  = 16,
 102         [CIP_SFC_96000]  = 16,
 103         [CIP_SFC_176400] = 32,
 104         [CIP_SFC_192000] = 32,
 105 };
 106 EXPORT_SYMBOL(amdtp_syt_intervals);
 107
 108 /**
 109  * amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream
 110  * @s:          the AMDTP stream, which must be initialized.
 111  * @runtime:    the PCM substream runtime
 112  */
 113 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
 114                                         struct snd_pcm_runtime *runtime)
 115 {
 116         int err;
 117
 118         /* AM824 in IEC 61883-6 can deliver 24bit data */
 119         err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
 120         if (err < 0)
 121                 goto end;
 122
 123         /*
 124          * Currently firewire-lib processes 16 packets in one software
 125          * interrupt callback. This equals to 2msec but actually the
 126          * interval of the interrupts has a jitter.
 127          * Additionally, even if adding a constraint to fit period size to
 128          * 2msec, actual calculated frames per period doesn't equal to 2msec,
 129          * depending on sampling rate.
 130          * Anyway, the interval to call snd_pcm_period_elapsed() cannot 2msec.
 131          * Here let us use 5msec for safe period interrupt.
 132          */
 133         err = snd_pcm_hw_constraint_minmax(runtime,
 134                                            SNDRV_PCM_HW_PARAM_PERIOD_TIME,
 135                                            5000, UINT_MAX);
 136         if (err < 0)
 137                 goto end;
 138
 139         /* Non-Blocking stream has no more constraints */
 140         if (!(s->flags & CIP_BLOCKING))
 141                 goto end;
 142
 143         /*
 144          * One AMDTP packet can include some frames. In blocking mode, the
 145          * number equals to SYT_INTERVAL. So the number is 8, 16 or 32,
 146          * depending on its sampling rate. For accurate period interrupt, it's
 147          * preferrable to aligh period/buffer sizes to current SYT_INTERVAL.
 148          *
 149          * TODO: These constraints can be improved with propper rules.
 150          * Currently apply LCM of SYT_INTEVALs.
 151          */
 152         err = snd_pcm_hw_constraint_step(runtime, 0,
 153                                          SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 32);
 154         if (err < 0)
 155                 goto end;
 156         err = snd_pcm_hw_constraint_step(runtime, 0,
 157                                          SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 32);
 158 end:
 159         return err;
 160 }
 161 EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints);
 162
 163 /**
 164  * amdtp_stream_set_parameters - set stream parameters
 165  * @s: the AMDTP stream to configure
 166  * @rate: the sample rate
 167  * @pcm_channels: the number of PCM samples in each data block, to be encoded
 168  *                as AM824 multi-bit linear audio
 169  * @midi_ports: the number of MIDI ports (i.e., MPX-MIDI Data Channels)
 170  *
 171  * The parameters must be set before the stream is started, and must not be
 172  * changed while the stream is running.
 173  */
 174 void amdtp_stream_set_parameters(struct amdtp_stream *s,
 175                                  unsigned int rate,
 176                                  unsigned int pcm_channels,
 177                                  unsigned int midi_ports)
 178 {
 179         static const unsigned int rates[] = {
 180                 [CIP_SFC_32000]  =  32000,
 181                 [CIP_SFC_44100]  =  44100,
 182                 [CIP_SFC_48000]  =  48000,
 183                 [CIP_SFC_88200]  =  88200,
 184                 [CIP_SFC_96000]  =  96000,
 185                 [CIP_SFC_176400] = 176400,
 186                 [CIP_SFC_192000] = 192000,
 187         };
 188         unsigned int i, sfc, midi_channels;
 189
 190         midi_channels = DIV_ROUND_UP(midi_ports, 8);
 191
 192         if (WARN_ON(amdtp_stream_running(s)) |
 193             WARN_ON(pcm_channels > AMDTP_MAX_CHANNELS_FOR_PCM) |
 194             WARN_ON(midi_channels > AMDTP_MAX_CHANNELS_FOR_MIDI))
 195                 return;
 196
 197         for (sfc = 0; sfc < CIP_SFC_COUNT; ++sfc)
 198                 if (rates[sfc] == rate)
 199                         goto sfc_found;
 200         WARN_ON(1);
 201         return;
 202
 203 sfc_found:
 204         s->pcm_channels = pcm_channels;
 205         s->sfc = sfc;
 206         s->data_block_quadlets = s->pcm_channels + midi_channels;
 207         s->midi_ports = midi_ports;
 208
 209         s->syt_interval = amdtp_syt_intervals[sfc];
 210
 211         /* default buffering in the device */
 212         s->transfer_delay = TRANSFER_DELAY_TICKS - TICKS_PER_CYCLE;
 213         if (s->flags & CIP_BLOCKING)
 214                 /* additional buffering needed to adjust for no-data packets */
 215                 s->transfer_delay += TICKS_PER_SECOND * s->syt_interval / rate;
 216
 217         /* init the position map for PCM and MIDI channels */
 218         for (i = 0; i < pcm_channels; i++)
 219                 s->pcm_positions[i] = i;
 220         s->midi_position = s->pcm_channels;
 221 }
 222 EXPORT_SYMBOL(amdtp_stream_set_parameters);
 223
 224 /**
 225  * amdtp_stream_get_max_payload - get the stream's packet size
 226  * @s: the AMDTP stream
 227  *
 228  * This function must not be called before the stream has been configured
 229  * with amdtp_stream_set_parameters().
 230  */
 231 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s)
 232 {
 233         return 8 + s->syt_interval * s->data_block_quadlets * 4;
 234 }
 235 EXPORT_SYMBOL(amdtp_stream_get_max_payload);
 236
 237 static void amdtp_write_s16(struct amdtp_stream *s,
 238                             struct snd_pcm_substream *pcm,
 239                             __be32 *buffer, unsigned int frames);
 240 static void amdtp_write_s32(struct amdtp_stream *s,
 241                             struct snd_pcm_substream *pcm,
 242                             __be32 *buffer, unsigned int frames);
 243 static void amdtp_read_s32(struct amdtp_stream *s,
 244                            struct snd_pcm_substream *pcm,
 245                            __be32 *buffer, unsigned int frames);
 246
 247 /**
 248  * amdtp_stream_set_pcm_format - set the PCM format
 249  * @s: the AMDTP stream to configure
 250  * @format: the format of the ALSA PCM device
 251  *
 252  * The sample format must be set after the other paramters (rate/PCM channels/
 253  * MIDI) and before the stream is started, and must not be changed while the
 254  * stream is running.
 255  */
 256 void amdtp_stream_set_pcm_format(struct amdtp_stream *s,
 257                                  snd_pcm_format_t format)
 258 {
 259         if (WARN_ON(amdtp_stream_pcm_running(s)))
 260                 return;
 261
 262         switch (format) {
 263         default:
 264                 WARN_ON(1);
 265                 /* fall through */
 266         case SNDRV_PCM_FORMAT_S16:
 267                 if (s->direction == AMDTP_OUT_STREAM) {
 268                         s->transfer_samples = amdtp_write_s16;
 269                         break;
 270                 }
 271                 WARN_ON(1);
 272                 /* fall through */
 273         case SNDRV_PCM_FORMAT_S32:
 274                 if (s->direction == AMDTP_OUT_STREAM)
 275                         s->transfer_samples = amdtp_write_s32;
 276                 else
 277                         s->transfer_samples = amdtp_read_s32;
 278                 break;
 279         }
 280 }
 281 EXPORT_SYMBOL(amdtp_stream_set_pcm_format);
 282
 283 /**
 284  * amdtp_stream_pcm_prepare - prepare PCM device for running
 285  * @s: the AMDTP stream
 286  *
 287  * This function should be called from the PCM device's .prepare callback.
 288  */
 289 void amdtp_stream_pcm_prepare(struct amdtp_stream *s)
 290 {
 291         tasklet_kill(&s->period_tasklet);
 292         s->pcm_buffer_pointer = 0;
 293         s->pcm_period_pointer = 0;
 294         s->pointer_flush = true;
 295 }
 296 EXPORT_SYMBOL(amdtp_stream_pcm_prepare);
 297
 298 static unsigned int calculate_data_blocks(struct amdtp_stream *s)
 299 {
 300         unsigned int phase, data_blocks;
 301
 302         if (s->flags & CIP_BLOCKING)
 303                 data_blocks = s->syt_interval;
 304         else if (!cip_sfc_is_base_44100(s->sfc)) {
 305                 /* Sample_rate / 8000 is an integer, and precomputed. */
 306                 data_blocks = s->data_block_state;
 307         } else {
 308                 phase = s->data_block_state;
 309
 310                 /*
 311                  * This calculates the number of data blocks per packet so that
 312                  * 1) the overall rate is correct and exactly synchronized to
 313                  *    the bus clock, and
 314                  * 2) packets with a rounded-up number of blocks occur as early
 315                  *    as possible in the sequence (to prevent underruns of the
 316                  *    device's buffer).
 317                  */
 318                 if (s->sfc == CIP_SFC_44100)
 319                         /* 6 6 5 6 5 6 5 ... */
 320                         data_blocks = 5 + ((phase & 1) ^
 321                                            (phase == 0 || phase >= 40));
 322                 else
 323                         /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
 324                         data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
 325                 if (++phase >= (80 >> (s->sfc >> 1)))
 326                         phase = 0;
 327                 s->data_block_state = phase;
 328         }
 329
 330         return data_blocks;
 331 }
 332
 333 static unsigned int calculate_syt(struct amdtp_stream *s,
 334                                   unsigned int cycle)
 335 {
 336         unsigned int syt_offset, phase, index, syt;
 337
 338         if (s->last_syt_offset < TICKS_PER_CYCLE) {
 339                 if (!cip_sfc_is_base_44100(s->sfc))
 340                         syt_offset = s->last_syt_offset + s->syt_offset_state;
 341                 else {
 342                 /*
 343                  * The time, in ticks, of the n'th SYT_INTERVAL sample is:
 344                  *   n * SYT_INTERVAL * 24576000 / sample_rate
 345                  * Modulo TICKS_PER_CYCLE, the difference between successive
 346                  * elements is about 1386.23.  Rounding the results of this
 347                  * formula to the SYT precision results in a sequence of
 348                  * differences that begins with:
 349                  *   1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
 350                  * This code generates _exactly_ the same sequence.
 351                  */
 352                         phase = s->syt_offset_state;
 353                         index = phase % 13;
 354                         syt_offset = s->last_syt_offset;
 355                         syt_offset += 1386 + ((index && !(index & 3)) ||
 356                                               phase == 146);
 357                         if (++phase >= 147)
 358                                 phase = 0;
 359                         s->syt_offset_state = phase;
 360                 }
 361         } else
 362                 syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
 363         s->last_syt_offset = syt_offset;
 364
 365         if (syt_offset < TICKS_PER_CYCLE) {
 366                 syt_offset += s->transfer_delay;
 367                 syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
 368                 syt += syt_offset % TICKS_PER_CYCLE;
 369
 370                 return syt & CIP_SYT_MASK;
 371         } else {
 372                 return CIP_SYT_NO_INFO;
 373         }
 374 }
 375
 376 static void amdtp_write_s32(struct amdtp_stream *s,
 377                             struct snd_pcm_substream *pcm,
 378                             __be32 *buffer, unsigned int frames)
 379 {
 380         struct snd_pcm_runtime *runtime = pcm->runtime;
 381         unsigned int channels, remaining_frames, i, c;
 382         const u32 *src;
 383
 384         channels = s->pcm_channels;
 385         src = (void *)runtime->dma_area +
 386                         frames_to_bytes(runtime, s->pcm_buffer_pointer);
 387         remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
 388
 389         for (i = 0; i < frames; ++i) {
 390                 for (c = 0; c < channels; ++c) {
 391                         buffer[s->pcm_positions[c]] =
 392                                         cpu_to_be32((*src >> 8) | 0x40000000);
 393                         src++;
 394                 }
 395                 buffer += s->data_block_quadlets;
 396                 if (--remaining_frames == 0)
 397                         src = (void *)runtime->dma_area;
 398         }
 399 }
 400
 401 static void amdtp_write_s16(struct amdtp_stream *s,
 402                             struct snd_pcm_substream *pcm,
 403                             __be32 *buffer, unsigned int frames)
 404 {
 405         struct snd_pcm_runtime *runtime = pcm->runtime;
 406         unsigned int channels, remaining_frames, i, c;
 407         const u16 *src;
 408
 409         channels = s->pcm_channels;
 410         src = (void *)runtime->dma_area +
 411                         frames_to_bytes(runtime, s->pcm_buffer_pointer);
 412         remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
 413
 414         for (i = 0; i < frames; ++i) {
 415                 for (c = 0; c < channels; ++c) {
 416                         buffer[s->pcm_positions[c]] =
 417                                         cpu_to_be32((*src << 8) | 0x40000000);
 418                         src++;
 419                 }
 420                 buffer += s->data_block_quadlets;
 421                 if (--remaining_frames == 0)
 422                         src = (void *)runtime->dma_area;
 423         }
 424 }
 425
 426 static void amdtp_read_s32(struct amdtp_stream *s,
 427                            struct snd_pcm_substream *pcm,
 428                            __be32 *buffer, unsigned int frames)
 429 {
 430         struct snd_pcm_runtime *runtime = pcm->runtime;
 431         unsigned int channels, remaining_frames, i, c;
 432         u32 *dst;
 433
 434         channels = s->pcm_channels;
 435         dst  = (void *)runtime->dma_area +
 436                         frames_to_bytes(runtime, s->pcm_buffer_pointer);
 437         remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
 438
 439         for (i = 0; i < frames; ++i) {
 440                 for (c = 0; c < channels; ++c) {
 441                         *dst = be32_to_cpu(buffer[s->pcm_positions[c]]) << 8;
 442                         dst++;
 443                 }
 444                 buffer += s->data_block_quadlets;
 445                 if (--remaining_frames == 0)
 446                         dst = (void *)runtime->dma_area;
 447         }
 448 }
 449
 450 static void amdtp_fill_pcm_silence(struct amdtp_stream *s,
 451                                    __be32 *buffer, unsigned int frames)
 452 {
 453         unsigned int i, c;
 454
 455         for (i = 0; i < frames; ++i) {
 456                 for (c = 0; c < s->pcm_channels; ++c)
 457                         buffer[s->pcm_positions[c]] = cpu_to_be32(0x40000000);
 458                 buffer += s->data_block_quadlets;
 459         }
 460 }
 461
 462 static void amdtp_fill_midi(struct amdtp_stream *s,
 463                             __be32 *buffer, unsigned int frames)
 464 {
 465         unsigned int f, port;
 466         u8 *b;
 467
 468         for (f = 0; f < frames; f++) {
 469                 buffer[s->midi_position] = 0;
 470                 b = (u8 *)&buffer[s->midi_position];
 471
 472                 port = (s->data_block_counter + f) % 8;
 473                 if ((s->midi[port] == NULL) ||
 474                     (snd_rawmidi_transmit(s->midi[port], b + 1, 1) <= 0))
 475                         b[0] = 0x80;
 476                 else
 477                         b[0] = 0x81;
 478
 479                 buffer += s->data_block_quadlets;
 480         }
 481 }
 482
 483 static void amdtp_pull_midi(struct amdtp_stream *s,
 484                             __be32 *buffer, unsigned int frames)
 485 {
 486         unsigned int f, port;
 487         int len;
 488         u8 *b;
 489
 490         for (f = 0; f < frames; f++) {
 491                 port = (s->data_block_counter + f) % 8;
 492                 b = (u8 *)&buffer[s->midi_position];
 493
 494                 len = b[0] - 0x80;
 495                 if ((1 <= len) &&  (len <= 3) && (s->midi[port]))
 496                         snd_rawmidi_receive(s->midi[port], b + 1, len);
 497
 498                 buffer += s->data_block_quadlets;
 499         }
 500 }
 501
 502 static void update_pcm_pointers(struct amdtp_stream *s,
 503                                 struct snd_pcm_substream *pcm,
 504                                 unsigned int frames)
 505 {       unsigned int ptr;
 506
 507         ptr = s->pcm_buffer_pointer + frames;
 508         if (ptr >= pcm->runtime->buffer_size)
 509                 ptr -= pcm->runtime->buffer_size;
 510         ACCESS_ONCE(s->pcm_buffer_pointer) = ptr;
 511
 512         s->pcm_period_pointer += frames;
 513         if (s->pcm_period_pointer >= pcm->runtime->period_size) {
 514                 s->pcm_period_pointer -= pcm->runtime->period_size;
 515                 s->pointer_flush = false;
 516                 tasklet_hi_schedule(&s->period_tasklet);
 517         }
 518 }
 519
 520 static void pcm_period_tasklet(unsigned long data)
 521 {
 522         struct amdtp_stream *s = (void *)data;
 523         struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm);
 524
 525         if (pcm)
 526                 snd_pcm_period_elapsed(pcm);
 527 }
 528
 529 static int queue_packet(struct amdtp_stream *s,
 530                         unsigned int header_length,
 531                         unsigned int payload_length, bool skip)
 532 {
 533         struct fw_iso_packet p = {0};
 534         int err = 0;
 535
 536         if (IS_ERR(s->context))
 537                 goto end;
 538
 539         p.interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL);
 540         p.tag = TAG_CIP;
 541         p.header_length = header_length;
 542         p.payload_length = (!skip) ? payload_length : 0;
 543         p.skip = skip;
 544         err = fw_iso_context_queue(s->context, &p, &s->buffer.iso_buffer,
 545                                    s->buffer.packets[s->packet_index].offset);
 546         if (err < 0) {
 547                 dev_err(&s->unit->device, "queueing error: %d\n", err);
 548                 goto end;
 549         }
 550
 551         if (++s->packet_index >= QUEUE_LENGTH)
 552                 s->packet_index = 0;
 553 end:
 554         return err;
 555 }
 556
 557 static inline int queue_out_packet(struct amdtp_stream *s,
 558                                    unsigned int payload_length, bool skip)
 559 {
 560         return queue_packet(s, OUT_PACKET_HEADER_SIZE,
 561                             payload_length, skip);
 562 }
 563
 564 static inline int queue_in_packet(struct amdtp_stream *s)
 565 {
 566         return queue_packet(s, IN_PACKET_HEADER_SIZE,
 567                             amdtp_stream_get_max_payload(s), false);
 568 }
 569
 570 static void handle_out_packet(struct amdtp_stream *s, unsigned int syt)
 571 {
 572         __be32 *buffer;
 573         unsigned int data_blocks, payload_length;
 574         struct snd_pcm_substream *pcm;
 575
 576         if (s->packet_index < 0)
 577                 return;
 578
 579         /* this module generate empty packet for 'no data' */
 580         if (!(s->flags & CIP_BLOCKING) || (syt != CIP_SYT_NO_INFO))
 581                 data_blocks = calculate_data_blocks(s);
 582         else
 583                 data_blocks = 0;
 584
 585         buffer = s->buffer.packets[s->packet_index].buffer;
 586         buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) |
 587                                 (s->data_block_quadlets << AMDTP_DBS_SHIFT) |
 588                                 s->data_block_counter);
 589         buffer[1] = cpu_to_be32(CIP_EOH | CIP_FMT_AM | AMDTP_FDF_AM824 |
 590                                 (s->sfc << CIP_FDF_SFC_SHIFT) | syt);
 591         buffer += 2;
 592
 593         pcm = ACCESS_ONCE(s->pcm);
 594         if (pcm)
 595                 s->transfer_samples(s, pcm, buffer, data_blocks);
 596         else
 597                 amdtp_fill_pcm_silence(s, buffer, data_blocks);
 598         if (s->midi_ports)
 599                 amdtp_fill_midi(s, buffer, data_blocks);
 600
 601         s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
 602
 603         payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
 604         if (queue_out_packet(s, payload_length, false) < 0) {
 605                 s->packet_index = -1;
 606                 amdtp_stream_pcm_abort(s);
 607                 return;
 608         }
 609
 610         if (pcm)
 611                 update_pcm_pointers(s, pcm, data_blocks);
 612 }
 613
 614 static void handle_in_packet(struct amdtp_stream *s,
 615                              unsigned int payload_quadlets,
 616                              __be32 *buffer)
 617 {
 618         u32 cip_header[2];
 619         unsigned int data_blocks, data_block_quadlets, data_block_counter;
 620         struct snd_pcm_substream *pcm = NULL;
 621
 622         cip_header[0] = be32_to_cpu(buffer[0]);
 623         cip_header[1] = be32_to_cpu(buffer[1]);
 624
 625         /*
 626          * This module supports 'Two-quadlet CIP header with SYT field'.
 627          * For convenience, also check FMT field is AM824 or not.
 628          */
 629         if (((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) ||
 630             ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH) ||
 631             ((cip_header[1] & CIP_FMT_MASK) != CIP_FMT_AM)) {
 632                 dev_info_ratelimited(&s->unit->device,
 633                                 "Invalid CIP header for AMDTP: %08X:%08X\n",
 634                                 cip_header[0], cip_header[1]);
 635                 goto end;
 636         }
 637
 638         /* Calculate data blocks */
 639         if (payload_quadlets < 3 ||
 640             ((cip_header[1] & CIP_FDF_MASK) ==
 641                                 (AMDTP_FDF_NO_DATA << CIP_FDF_SFC_SHIFT))) {
 642                 data_blocks = 0;
 643         } else {
 644                 data_block_quadlets =
 645                         (cip_header[0] & AMDTP_DBS_MASK) >> AMDTP_DBS_SHIFT;
 646                 /* avoid division by zero */
 647                 if (data_block_quadlets == 0) {
 648                         dev_info_ratelimited(&s->unit->device,
 649                                 "Detect invalid value in dbs field: %08X\n",
 650                                 cip_header[0]);
 651                         goto err;
 652                 }
 653
 654                 data_blocks = (payload_quadlets - 2) / data_block_quadlets;
 655         }
 656
 657         /* Check data block counter continuity */
 658         data_block_counter = cip_header[0] & AMDTP_DBC_MASK;
 659         if (data_block_counter != s->data_block_counter) {
 660                 dev_info(&s->unit->device,
 661                          "Detect discontinuity of CIP: %02X %02X\n",
 662                          s->data_block_counter, data_block_counter);
 663                 goto err;
 664         }
 665
 666         if (data_blocks > 0) {
 667                 buffer += 2;
 668
 669                 pcm = ACCESS_ONCE(s->pcm);
 670                 if (pcm)
 671                         s->transfer_samples(s, pcm, buffer, data_blocks);
 672
 673                 if (s->midi_ports)
 674                         amdtp_pull_midi(s, buffer, data_blocks);
 675         }
 676
 677         s->data_block_counter = (data_block_counter + data_blocks) & 0xff;
 678 end:
 679         if (queue_in_packet(s) < 0)
 680                 goto err;
 681
 682         if (pcm)
 683                 update_pcm_pointers(s, pcm, data_blocks);
 684
 685         return;
 686 err:
 687         s->packet_index = -1;
 688         amdtp_stream_pcm_abort(s);
 689 }
 690
 691 static void out_stream_callback(struct fw_iso_context *context, u32 cycle,
 692                                 size_t header_length, void *header,
 693                                 void *private_data)
 694 {
 695         struct amdtp_stream *s = private_data;
 696         unsigned int i, syt, packets = header_length / 4;
 697
 698         /*
 699          * Compute the cycle of the last queued packet.
 700          * (We need only the four lowest bits for the SYT, so we can ignore
 701          * that bits 0-11 must wrap around at 3072.)
 702          */
 703         cycle += QUEUE_LENGTH - packets;
 704
 705         for (i = 0; i < packets; ++i) {
 706                 syt = calculate_syt(s, ++cycle);
 707                 handle_out_packet(s, syt);
 708         }
 709         fw_iso_context_queue_flush(s->context);
 710 }
 711
 712 static void in_stream_callback(struct fw_iso_context *context, u32 cycle,
 713                                size_t header_length, void *header,
 714                                void *private_data)
 715 {
 716         struct amdtp_stream *s = private_data;
 717         unsigned int p, syt, packets, payload_quadlets;
 718         __be32 *buffer, *headers = header;
 719
 720         /* The number of packets in buffer */
 721         packets = header_length / IN_PACKET_HEADER_SIZE;
 722
 723         for (p = 0; p < packets; p++) {
 724                 if (s->packet_index < 0)
 725                         break;
 726
 727                 buffer = s->buffer.packets[s->packet_index].buffer;
 728
 729                 /* Process sync slave stream */
 730                 if (s->sync_slave && s->sync_slave->callbacked) {
 731                         syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK;
 732                         handle_out_packet(s->sync_slave, syt);
 733                 }
 734
 735                 /* The number of quadlets in this packet */
 736                 payload_quadlets =
 737                         (be32_to_cpu(headers[p]) >> ISO_DATA_LENGTH_SHIFT) / 4;
 738                 handle_in_packet(s, payload_quadlets, buffer);
 739         }
 740
 741         /* Queueing error or detecting discontinuity */
 742         if (s->packet_index < 0) {
 743                 /* Abort sync slave. */
 744                 if (s->sync_slave) {
 745                         s->sync_slave->packet_index = -1;
 746                         amdtp_stream_pcm_abort(s->sync_slave);
 747                 }
 748                 return;
 749         }
 750
 751         /* when sync to device, flush the packets for slave stream */
 752         if (s->sync_slave && s->sync_slave->callbacked)
 753                 fw_iso_context_queue_flush(s->sync_slave->context);
 754
 755         fw_iso_context_queue_flush(s->context);
 756 }
 757
 758 /* processing is done by master callback */
 759 static void slave_stream_callback(struct fw_iso_context *context, u32 cycle,
 760                                   size_t header_length, void *header,
 761                                   void *private_data)
 762 {
 763         return;
 764 }
 765
 766 /* this is executed one time */
 767 static void amdtp_stream_first_callback(struct fw_iso_context *context,
 768                                         u32 cycle, size_t header_length,
 769                                         void *header, void *private_data)
 770 {
 771         struct amdtp_stream *s = private_data;
 772
 773         /*
 774          * For in-stream, first packet has come.
 775          * For out-stream, prepared to transmit first packet
 776          */
 777         s->callbacked = true;
 778         wake_up(&s->callback_wait);
 779
 780         if (s->direction == AMDTP_IN_STREAM)
 781                 context->callback.sc = in_stream_callback;
 782         else if ((s->flags & CIP_BLOCKING) && (s->flags & CIP_SYNC_TO_DEVICE))
 783                 context->callback.sc = slave_stream_callback;
 784         else
 785                 context->callback.sc = out_stream_callback;
 786
 787         context->callback.sc(context, cycle, header_length, header, s);
 788 }
 789
 790 /**
 791  * amdtp_stream_start - start transferring packets
 792  * @s: the AMDTP stream to start
 793  * @channel: the isochronous channel on the bus
 794  * @speed: firewire speed code
 795  *
 796  * The stream cannot be started until it has been configured with
 797  * amdtp_stream_set_parameters() and it must be started before any PCM or MIDI
 798  * device can be started.
 799  */
 800 int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
 801 {
 802         static const struct {
 803                 unsigned int data_block;
 804                 unsigned int syt_offset;
 805         } initial_state[] = {
 806                 [CIP_SFC_32000]  = {  4, 3072 },
 807                 [CIP_SFC_48000]  = {  6, 1024 },
 808                 [CIP_SFC_96000]  = { 12, 1024 },
 809                 [CIP_SFC_192000] = { 24, 1024 },
 810                 [CIP_SFC_44100]  = {  0,   67 },
 811                 [CIP_SFC_88200]  = {  0,   67 },
 812                 [CIP_SFC_176400] = {  0,   67 },
 813         };
 814         unsigned int header_size;
 815         enum dma_data_direction dir;
 816         int type, err;
 817
 818         mutex_lock(&s->mutex);
 819
 820         if (WARN_ON(amdtp_stream_running(s) ||
 821                     (s->data_block_quadlets < 1))) {
 822                 err = -EBADFD;
 823                 goto err_unlock;
 824         }
 825
 826         s->data_block_counter = 0;
 827         s->data_block_state = initial_state[s->sfc].data_block;
 828         s->syt_offset_state = initial_state[s->sfc].syt_offset;
 829         s->last_syt_offset = TICKS_PER_CYCLE;
 830
 831         /* initialize packet buffer */
 832         if (s->direction == AMDTP_IN_STREAM) {
 833                 dir = DMA_FROM_DEVICE;
 834                 type = FW_ISO_CONTEXT_RECEIVE;
 835                 header_size = IN_PACKET_HEADER_SIZE;
 836         } else {
 837                 dir = DMA_TO_DEVICE;
 838                 type = FW_ISO_CONTEXT_TRANSMIT;
 839                 header_size = OUT_PACKET_HEADER_SIZE;
 840         }
 841         err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
 842                                       amdtp_stream_get_max_payload(s), dir);
 843         if (err < 0)
 844                 goto err_unlock;
 845
 846         s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
 847                                            type, channel, speed, header_size,
 848                                            amdtp_stream_first_callback, s);
 849         if (IS_ERR(s->context)) {
 850                 err = PTR_ERR(s->context);
 851                 if (err == -EBUSY)
 852                         dev_err(&s->unit->device,
 853                                 "no free stream on this controller\n");
 854                 goto err_buffer;
 855         }
 856
 857         amdtp_stream_update(s);
 858
 859         s->packet_index = 0;
 860         do {
 861                 if (s->direction == AMDTP_IN_STREAM)
 862                         err = queue_in_packet(s);
 863                 else
 864                         err = queue_out_packet(s, 0, true);
 865                 if (err < 0)
 866                         goto err_context;
 867         } while (s->packet_index > 0);
 868
 869         /* NOTE: TAG1 matches CIP. This just affects in stream. */
 870         s->callbacked = false;
 871         err = fw_iso_context_start(s->context, -1, 0,
 872                                    FW_ISO_CONTEXT_MATCH_TAG1);
 873         if (err < 0)
 874                 goto err_context;
 875
 876         mutex_unlock(&s->mutex);
 877
 878         return 0;
 879
 880 err_context:
 881         fw_iso_context_destroy(s->context);
 882         s->context = ERR_PTR(-1);
 883 err_buffer:
 884         iso_packets_buffer_destroy(&s->buffer, s->unit);
 885 err_unlock:
 886         mutex_unlock(&s->mutex);
 887
 888         return err;
 889 }
 890 EXPORT_SYMBOL(amdtp_stream_start);
 891
 892 /**
 893  * amdtp_stream_pcm_pointer - get the PCM buffer position
 894  * @s: the AMDTP stream that transports the PCM data
 895  *
 896  * Returns the current buffer position, in frames.
 897  */
 898 unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s)
 899 {
 900         /* this optimization is allowed to be racy */
 901         if (s->pointer_flush)
 902                 fw_iso_context_flush_completions(s->context);
 903         else
 904                 s->pointer_flush = true;
 905
 906         return ACCESS_ONCE(s->pcm_buffer_pointer);
 907 }
 908 EXPORT_SYMBOL(amdtp_stream_pcm_pointer);
 909
 910 /**
 911  * amdtp_stream_update - update the stream after a bus reset
 912  * @s: the AMDTP stream
 913  */
 914 void amdtp_stream_update(struct amdtp_stream *s)
 915 {
 916         ACCESS_ONCE(s->source_node_id_field) =
 917                 (fw_parent_device(s->unit)->card->node_id & 0x3f) << 24;
 918 }
 919 EXPORT_SYMBOL(amdtp_stream_update);
 920
 921 /**
 922  * amdtp_stream_stop - stop sending packets
 923  * @s: the AMDTP stream to stop
 924  *
 925  * All PCM and MIDI devices of the stream must be stopped before the stream
 926  * itself can be stopped.
 927  */
 928 void amdtp_stream_stop(struct amdtp_stream *s)
 929 {
 930         mutex_lock(&s->mutex);
 931
 932         if (!amdtp_stream_running(s)) {
 933                 mutex_unlock(&s->mutex);
 934                 return;
 935         }
 936
 937         tasklet_kill(&s->period_tasklet);
 938         fw_iso_context_stop(s->context);
 939         fw_iso_context_destroy(s->context);
 940         s->context = ERR_PTR(-1);
 941         iso_packets_buffer_destroy(&s->buffer, s->unit);
 942
 943         s->callbacked = false;
 944
 945         mutex_unlock(&s->mutex);
 946 }
 947 EXPORT_SYMBOL(amdtp_stream_stop);
 948
 949 /**
 950  * amdtp_stream_pcm_abort - abort the running PCM device
 951  * @s: the AMDTP stream about to be stopped
 952  *
 953  * If the isochronous stream needs to be stopped asynchronously, call this
 954  * function first to stop the PCM device.
 955  */
 956 void amdtp_stream_pcm_abort(struct amdtp_stream *s)
 957 {
 958         struct snd_pcm_substream *pcm;
 959
 960         pcm = ACCESS_ONCE(s->pcm);
 961         if (pcm) {
 962                 snd_pcm_stream_lock_irq(pcm);
 963                 if (snd_pcm_running(pcm))
 964                         snd_pcm_stop(pcm, SNDRV_PCM_STATE_XRUN);
 965                 snd_pcm_stream_unlock_irq(pcm);
 966         }
 967 }
 968 EXPORT_SYMBOL(amdtp_stream_pcm_abort);