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         s->rx_blocks_for_midi = UINT_MAX;
  82
  83         return 0;
  84 }
  85 EXPORT_SYMBOL(amdtp_stream_init);
  86
  87 /**
  88  * amdtp_stream_destroy - free stream resources
  89  * @s: the AMDTP stream to destroy
  90  */
  91 void amdtp_stream_destroy(struct amdtp_stream *s)
  92 {
  93         WARN_ON(amdtp_stream_running(s));
  94         mutex_destroy(&s->mutex);
  95         fw_unit_put(s->unit);
  96 }
  97 EXPORT_SYMBOL(amdtp_stream_destroy);
  98
  99 const unsigned int amdtp_syt_intervals[CIP_SFC_COUNT] = {
 100         [CIP_SFC_32000]  =  8,
 101         [CIP_SFC_44100]  =  8,
 102         [CIP_SFC_48000]  =  8,
 103         [CIP_SFC_88200]  = 16,
 104         [CIP_SFC_96000]  = 16,
 105         [CIP_SFC_176400] = 32,
 106         [CIP_SFC_192000] = 32,
 107 };
 108 EXPORT_SYMBOL(amdtp_syt_intervals);
 109
 110 const unsigned int amdtp_rate_table[CIP_SFC_COUNT] = {
 111         [CIP_SFC_32000]  =  32000,
 112         [CIP_SFC_44100]  =  44100,
 113         [CIP_SFC_48000]  =  48000,
 114         [CIP_SFC_88200]  =  88200,
 115         [CIP_SFC_96000]  =  96000,
 116         [CIP_SFC_176400] = 176400,
 117         [CIP_SFC_192000] = 192000,
 118 };
 119 EXPORT_SYMBOL(amdtp_rate_table);
 120
 121 /**
 122  * amdtp_stream_add_pcm_hw_constraints - add hw constraints for PCM substream
 123  * @s:          the AMDTP stream, which must be initialized.
 124  * @runtime:    the PCM substream runtime
 125  */
 126 int amdtp_stream_add_pcm_hw_constraints(struct amdtp_stream *s,
 127                                         struct snd_pcm_runtime *runtime)
 128 {
 129         int err;
 130
 131         /* AM824 in IEC 61883-6 can deliver 24bit data */
 132         err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
 133         if (err < 0)
 134                 goto end;
 135
 136         /*
 137          * Currently firewire-lib processes 16 packets in one software
 138          * interrupt callback. This equals to 2msec but actually the
 139          * interval of the interrupts has a jitter.
 140          * Additionally, even if adding a constraint to fit period size to
 141          * 2msec, actual calculated frames per period doesn't equal to 2msec,
 142          * depending on sampling rate.
 143          * Anyway, the interval to call snd_pcm_period_elapsed() cannot 2msec.
 144          * Here let us use 5msec for safe period interrupt.
 145          */
 146         err = snd_pcm_hw_constraint_minmax(runtime,
 147                                            SNDRV_PCM_HW_PARAM_PERIOD_TIME,
 148                                            5000, UINT_MAX);
 149         if (err < 0)
 150                 goto end;
 151
 152         /* Non-Blocking stream has no more constraints */
 153         if (!(s->flags & CIP_BLOCKING))
 154                 goto end;
 155
 156         /*
 157          * One AMDTP packet can include some frames. In blocking mode, the
 158          * number equals to SYT_INTERVAL. So the number is 8, 16 or 32,
 159          * depending on its sampling rate. For accurate period interrupt, it's
 160          * preferrable to aligh period/buffer sizes to current SYT_INTERVAL.
 161          *
 162          * TODO: These constraints can be improved with propper rules.
 163          * Currently apply LCM of SYT_INTEVALs.
 164          */
 165         err = snd_pcm_hw_constraint_step(runtime, 0,
 166                                          SNDRV_PCM_HW_PARAM_PERIOD_SIZE, 32);
 167         if (err < 0)
 168                 goto end;
 169         err = snd_pcm_hw_constraint_step(runtime, 0,
 170                                          SNDRV_PCM_HW_PARAM_BUFFER_SIZE, 32);
 171 end:
 172         return err;
 173 }
 174 EXPORT_SYMBOL(amdtp_stream_add_pcm_hw_constraints);
 175
 176 /**
 177  * amdtp_stream_set_parameters - set stream parameters
 178  * @s: the AMDTP stream to configure
 179  * @rate: the sample rate
 180  * @pcm_channels: the number of PCM samples in each data block, to be encoded
 181  *                as AM824 multi-bit linear audio
 182  * @midi_ports: the number of MIDI ports (i.e., MPX-MIDI Data Channels)
 183  *
 184  * The parameters must be set before the stream is started, and must not be
 185  * changed while the stream is running.
 186  */
 187 void amdtp_stream_set_parameters(struct amdtp_stream *s,
 188                                  unsigned int rate,
 189                                  unsigned int pcm_channels,
 190                                  unsigned int midi_ports)
 191 {
 192         unsigned int i, sfc, midi_channels;
 193
 194         midi_channels = DIV_ROUND_UP(midi_ports, 8);
 195
 196         if (WARN_ON(amdtp_stream_running(s)) |
 197             WARN_ON(pcm_channels > AMDTP_MAX_CHANNELS_FOR_PCM) |
 198             WARN_ON(midi_channels > AMDTP_MAX_CHANNELS_FOR_MIDI))
 199                 return;
 200
 201         for (sfc = 0; sfc < ARRAY_SIZE(amdtp_rate_table); ++sfc)
 202                 if (amdtp_rate_table[sfc] == rate)
 203                         goto sfc_found;
 204         WARN_ON(1);
 205         return;
 206
 207 sfc_found:
 208         s->pcm_channels = pcm_channels;
 209         s->sfc = sfc;
 210         s->data_block_quadlets = s->pcm_channels + midi_channels;
 211         s->midi_ports = midi_ports;
 212
 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         /* init the position map for PCM and MIDI channels */
 222         for (i = 0; i < pcm_channels; i++)
 223                 s->pcm_positions[i] = i;
 224         s->midi_position = s->pcm_channels;
 225 }
 226 EXPORT_SYMBOL(amdtp_stream_set_parameters);
 227
 228 /**
 229  * amdtp_stream_get_max_payload - get the stream's packet size
 230  * @s: the AMDTP stream
 231  *
 232  * This function must not be called before the stream has been configured
 233  * with amdtp_stream_set_parameters().
 234  */
 235 unsigned int amdtp_stream_get_max_payload(struct amdtp_stream *s)
 236 {
 237         return 8 + s->syt_interval * s->data_block_quadlets * 4;
 238 }
 239 EXPORT_SYMBOL(amdtp_stream_get_max_payload);
 240
 241 static void amdtp_write_s16(struct amdtp_stream *s,
 242                             struct snd_pcm_substream *pcm,
 243                             __be32 *buffer, unsigned int frames);
 244 static void amdtp_write_s32(struct amdtp_stream *s,
 245                             struct snd_pcm_substream *pcm,
 246                             __be32 *buffer, unsigned int frames);
 247 static void amdtp_read_s32(struct amdtp_stream *s,
 248                            struct snd_pcm_substream *pcm,
 249                            __be32 *buffer, unsigned int frames);
 250
 251 /**
 252  * amdtp_stream_set_pcm_format - set the PCM format
 253  * @s: the AMDTP stream to configure
 254  * @format: the format of the ALSA PCM device
 255  *
 256  * The sample format must be set after the other paramters (rate/PCM channels/
 257  * MIDI) and before the stream is started, and must not be changed while the
 258  * stream is running.
 259  */
 260 void amdtp_stream_set_pcm_format(struct amdtp_stream *s,
 261                                  snd_pcm_format_t format)
 262 {
 263         if (WARN_ON(amdtp_stream_pcm_running(s)))
 264                 return;
 265
 266         switch (format) {
 267         default:
 268                 WARN_ON(1);
 269                 /* fall through */
 270         case SNDRV_PCM_FORMAT_S16:
 271                 if (s->direction == AMDTP_OUT_STREAM) {
 272                         s->transfer_samples = amdtp_write_s16;
 273                         break;
 274                 }
 275                 WARN_ON(1);
 276                 /* fall through */
 277         case SNDRV_PCM_FORMAT_S32:
 278                 if (s->direction == AMDTP_OUT_STREAM)
 279                         s->transfer_samples = amdtp_write_s32;
 280                 else
 281                         s->transfer_samples = amdtp_read_s32;
 282                 break;
 283         }
 284 }
 285 EXPORT_SYMBOL(amdtp_stream_set_pcm_format);
 286
 287 /**
 288  * amdtp_stream_pcm_prepare - prepare PCM device for running
 289  * @s: the AMDTP stream
 290  *
 291  * This function should be called from the PCM device's .prepare callback.
 292  */
 293 void amdtp_stream_pcm_prepare(struct amdtp_stream *s)
 294 {
 295         tasklet_kill(&s->period_tasklet);
 296         s->pcm_buffer_pointer = 0;
 297         s->pcm_period_pointer = 0;
 298         s->pointer_flush = true;
 299 }
 300 EXPORT_SYMBOL(amdtp_stream_pcm_prepare);
 301
 302 static unsigned int calculate_data_blocks(struct amdtp_stream *s)
 303 {
 304         unsigned int phase, data_blocks;
 305
 306         if (s->flags & CIP_BLOCKING)
 307                 data_blocks = s->syt_interval;
 308         else if (!cip_sfc_is_base_44100(s->sfc)) {
 309                 /* Sample_rate / 8000 is an integer, and precomputed. */
 310                 data_blocks = s->data_block_state;
 311         } else {
 312                 phase = s->data_block_state;
 313
 314                 /*
 315                  * This calculates the number of data blocks per packet so that
 316                  * 1) the overall rate is correct and exactly synchronized to
 317                  *    the bus clock, and
 318                  * 2) packets with a rounded-up number of blocks occur as early
 319                  *    as possible in the sequence (to prevent underruns of the
 320                  *    device's buffer).
 321                  */
 322                 if (s->sfc == CIP_SFC_44100)
 323                         /* 6 6 5 6 5 6 5 ... */
 324                         data_blocks = 5 + ((phase & 1) ^
 325                                            (phase == 0 || phase >= 40));
 326                 else
 327                         /* 12 11 11 11 11 ... or 23 22 22 22 22 ... */
 328                         data_blocks = 11 * (s->sfc >> 1) + (phase == 0);
 329                 if (++phase >= (80 >> (s->sfc >> 1)))
 330                         phase = 0;
 331                 s->data_block_state = phase;
 332         }
 333
 334         return data_blocks;
 335 }
 336
 337 static unsigned int calculate_syt(struct amdtp_stream *s,
 338                                   unsigned int cycle)
 339 {
 340         unsigned int syt_offset, phase, index, syt;
 341
 342         if (s->last_syt_offset < TICKS_PER_CYCLE) {
 343                 if (!cip_sfc_is_base_44100(s->sfc))
 344                         syt_offset = s->last_syt_offset + s->syt_offset_state;
 345                 else {
 346                 /*
 347                  * The time, in ticks, of the n'th SYT_INTERVAL sample is:
 348                  *   n * SYT_INTERVAL * 24576000 / sample_rate
 349                  * Modulo TICKS_PER_CYCLE, the difference between successive
 350                  * elements is about 1386.23.  Rounding the results of this
 351                  * formula to the SYT precision results in a sequence of
 352                  * differences that begins with:
 353                  *   1386 1386 1387 1386 1386 1386 1387 1386 1386 1386 1387 ...
 354                  * This code generates _exactly_ the same sequence.
 355                  */
 356                         phase = s->syt_offset_state;
 357                         index = phase % 13;
 358                         syt_offset = s->last_syt_offset;
 359                         syt_offset += 1386 + ((index && !(index & 3)) ||
 360                                               phase == 146);
 361                         if (++phase >= 147)
 362                                 phase = 0;
 363                         s->syt_offset_state = phase;
 364                 }
 365         } else
 366                 syt_offset = s->last_syt_offset - TICKS_PER_CYCLE;
 367         s->last_syt_offset = syt_offset;
 368
 369         if (syt_offset < TICKS_PER_CYCLE) {
 370                 syt_offset += s->transfer_delay;
 371                 syt = (cycle + syt_offset / TICKS_PER_CYCLE) << 12;
 372                 syt += syt_offset % TICKS_PER_CYCLE;
 373
 374                 return syt & CIP_SYT_MASK;
 375         } else {
 376                 return CIP_SYT_NO_INFO;
 377         }
 378 }
 379
 380 static void amdtp_write_s32(struct amdtp_stream *s,
 381                             struct snd_pcm_substream *pcm,
 382                             __be32 *buffer, unsigned int frames)
 383 {
 384         struct snd_pcm_runtime *runtime = pcm->runtime;
 385         unsigned int channels, remaining_frames, i, c;
 386         const u32 *src;
 387
 388         channels = s->pcm_channels;
 389         src = (void *)runtime->dma_area +
 390                         frames_to_bytes(runtime, s->pcm_buffer_pointer);
 391         remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
 392
 393         for (i = 0; i < frames; ++i) {
 394                 for (c = 0; c < channels; ++c) {
 395                         buffer[s->pcm_positions[c]] =
 396                                         cpu_to_be32((*src >> 8) | 0x40000000);
 397                         src++;
 398                 }
 399                 buffer += s->data_block_quadlets;
 400                 if (--remaining_frames == 0)
 401                         src = (void *)runtime->dma_area;
 402         }
 403 }
 404
 405 static void amdtp_write_s16(struct amdtp_stream *s,
 406                             struct snd_pcm_substream *pcm,
 407                             __be32 *buffer, unsigned int frames)
 408 {
 409         struct snd_pcm_runtime *runtime = pcm->runtime;
 410         unsigned int channels, remaining_frames, i, c;
 411         const u16 *src;
 412
 413         channels = s->pcm_channels;
 414         src = (void *)runtime->dma_area +
 415                         frames_to_bytes(runtime, s->pcm_buffer_pointer);
 416         remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
 417
 418         for (i = 0; i < frames; ++i) {
 419                 for (c = 0; c < channels; ++c) {
 420                         buffer[s->pcm_positions[c]] =
 421                                         cpu_to_be32((*src << 8) | 0x42000000);
 422                         src++;
 423                 }
 424                 buffer += s->data_block_quadlets;
 425                 if (--remaining_frames == 0)
 426                         src = (void *)runtime->dma_area;
 427         }
 428 }
 429
 430 static void amdtp_read_s32(struct amdtp_stream *s,
 431                            struct snd_pcm_substream *pcm,
 432                            __be32 *buffer, unsigned int frames)
 433 {
 434         struct snd_pcm_runtime *runtime = pcm->runtime;
 435         unsigned int channels, remaining_frames, i, c;
 436         u32 *dst;
 437
 438         channels = s->pcm_channels;
 439         dst  = (void *)runtime->dma_area +
 440                         frames_to_bytes(runtime, s->pcm_buffer_pointer);
 441         remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
 442
 443         for (i = 0; i < frames; ++i) {
 444                 for (c = 0; c < channels; ++c) {
 445                         *dst = be32_to_cpu(buffer[s->pcm_positions[c]]) << 8;
 446                         dst++;
 447                 }
 448                 buffer += s->data_block_quadlets;
 449                 if (--remaining_frames == 0)
 450                         dst = (void *)runtime->dma_area;
 451         }
 452 }
 453
 454 static void amdtp_fill_pcm_silence(struct amdtp_stream *s,
 455                                    __be32 *buffer, unsigned int frames)
 456 {
 457         unsigned int i, c;
 458
 459         for (i = 0; i < frames; ++i) {
 460                 for (c = 0; c < s->pcm_channels; ++c)
 461                         buffer[s->pcm_positions[c]] = cpu_to_be32(0x40000000);
 462                 buffer += s->data_block_quadlets;
 463         }
 464 }
 465
 466 static void amdtp_fill_midi(struct amdtp_stream *s,
 467                             __be32 *buffer, unsigned int frames)
 468 {
 469         unsigned int f, port;
 470         u8 *b;
 471
 472         for (f = 0; f < frames; f++) {
 473                 buffer[s->midi_position] = 0;
 474                 b = (u8 *)&buffer[s->midi_position];
 475
 476                 port = (s->data_block_counter + f) % 8;
 477                 if ((f >= s->rx_blocks_for_midi) ||
 478                     (s->midi[port] == NULL) ||
 479                     (snd_rawmidi_transmit(s->midi[port], b + 1, 1) <= 0))
 480                         b[0] = 0x80;
 481                 else
 482                         b[0] = 0x81;
 483
 484                 buffer += s->data_block_quadlets;
 485         }
 486 }
 487
 488 static void amdtp_pull_midi(struct amdtp_stream *s,
 489                             __be32 *buffer, unsigned int frames)
 490 {
 491         unsigned int f, port;
 492         int len;
 493         u8 *b;
 494
 495         for (f = 0; f < frames; f++) {
 496                 port = (s->data_block_counter + f) % 8;
 497                 b = (u8 *)&buffer[s->midi_position];
 498
 499                 len = b[0] - 0x80;
 500                 if ((1 <= len) &&  (len <= 3) && (s->midi[port]))
 501                         snd_rawmidi_receive(s->midi[port], b + 1, len);
 502
 503                 buffer += s->data_block_quadlets;
 504         }
 505 }
 506
 507 static void update_pcm_pointers(struct amdtp_stream *s,
 508                                 struct snd_pcm_substream *pcm,
 509                                 unsigned int frames)
 510 {
 511         unsigned int ptr;
 512
 513         /*
 514          * In IEC 61883-6, one data block represents one event. In ALSA, one
 515          * event equals to one PCM frame. But Dice has a quirk to transfer
 516          * two PCM frames in one data block.
 517          */
 518         if (s->double_pcm_frames)
 519                 frames *= 2;
 520
 521         ptr = s->pcm_buffer_pointer + frames;
 522         if (ptr >= pcm->runtime->buffer_size)
 523                 ptr -= pcm->runtime->buffer_size;
 524         ACCESS_ONCE(s->pcm_buffer_pointer) = ptr;
 525
 526         s->pcm_period_pointer += frames;
 527         if (s->pcm_period_pointer >= pcm->runtime->period_size) {
 528                 s->pcm_period_pointer -= pcm->runtime->period_size;
 529                 s->pointer_flush = false;
 530                 tasklet_hi_schedule(&s->period_tasklet);
 531         }
 532 }
 533
 534 static void pcm_period_tasklet(unsigned long data)
 535 {
 536         struct amdtp_stream *s = (void *)data;
 537         struct snd_pcm_substream *pcm = ACCESS_ONCE(s->pcm);
 538
 539         if (pcm)
 540                 snd_pcm_period_elapsed(pcm);
 541 }
 542
 543 static int queue_packet(struct amdtp_stream *s,
 544                         unsigned int header_length,
 545                         unsigned int payload_length, bool skip)
 546 {
 547         struct fw_iso_packet p = {0};
 548         int err = 0;
 549
 550         if (IS_ERR(s->context))
 551                 goto end;
 552
 553         p.interrupt = IS_ALIGNED(s->packet_index + 1, INTERRUPT_INTERVAL);
 554         p.tag = TAG_CIP;
 555         p.header_length = header_length;
 556         p.payload_length = (!skip) ? payload_length : 0;
 557         p.skip = skip;
 558         err = fw_iso_context_queue(s->context, &p, &s->buffer.iso_buffer,
 559                                    s->buffer.packets[s->packet_index].offset);
 560         if (err < 0) {
 561                 dev_err(&s->unit->device, "queueing error: %d\n", err);
 562                 goto end;
 563         }
 564
 565         if (++s->packet_index >= QUEUE_LENGTH)
 566                 s->packet_index = 0;
 567 end:
 568         return err;
 569 }
 570
 571 static inline int queue_out_packet(struct amdtp_stream *s,
 572                                    unsigned int payload_length, bool skip)
 573 {
 574         return queue_packet(s, OUT_PACKET_HEADER_SIZE,
 575                             payload_length, skip);
 576 }
 577
 578 static inline int queue_in_packet(struct amdtp_stream *s)
 579 {
 580         return queue_packet(s, IN_PACKET_HEADER_SIZE,
 581                             amdtp_stream_get_max_payload(s), false);
 582 }
 583
 584 static void handle_out_packet(struct amdtp_stream *s, unsigned int syt)
 585 {
 586         __be32 *buffer;
 587         unsigned int data_blocks, payload_length;
 588         struct snd_pcm_substream *pcm;
 589
 590         if (s->packet_index < 0)
 591                 return;
 592
 593         /* this module generate empty packet for 'no data' */
 594         if (!(s->flags & CIP_BLOCKING) || (syt != CIP_SYT_NO_INFO))
 595                 data_blocks = calculate_data_blocks(s);
 596         else
 597                 data_blocks = 0;
 598
 599         buffer = s->buffer.packets[s->packet_index].buffer;
 600         buffer[0] = cpu_to_be32(ACCESS_ONCE(s->source_node_id_field) |
 601                                 (s->data_block_quadlets << AMDTP_DBS_SHIFT) |
 602                                 s->data_block_counter);
 603         buffer[1] = cpu_to_be32(CIP_EOH | CIP_FMT_AM | AMDTP_FDF_AM824 |
 604                                 (s->sfc << CIP_FDF_SFC_SHIFT) | syt);
 605         buffer += 2;
 606
 607         pcm = ACCESS_ONCE(s->pcm);
 608         if (pcm)
 609                 s->transfer_samples(s, pcm, buffer, data_blocks);
 610         else
 611                 amdtp_fill_pcm_silence(s, buffer, data_blocks);
 612         if (s->midi_ports)
 613                 amdtp_fill_midi(s, buffer, data_blocks);
 614
 615         s->data_block_counter = (s->data_block_counter + data_blocks) & 0xff;
 616
 617         payload_length = 8 + data_blocks * 4 * s->data_block_quadlets;
 618         if (queue_out_packet(s, payload_length, false) < 0) {
 619                 s->packet_index = -1;
 620                 amdtp_stream_pcm_abort(s);
 621                 return;
 622         }
 623
 624         if (pcm)
 625                 update_pcm_pointers(s, pcm, data_blocks);
 626 }
 627
 628 static void handle_in_packet(struct amdtp_stream *s,
 629                              unsigned int payload_quadlets,
 630                              __be32 *buffer)
 631 {
 632         u32 cip_header[2];
 633         unsigned int data_blocks, data_block_quadlets, data_block_counter,
 634                      dbc_interval;
 635         struct snd_pcm_substream *pcm = NULL;
 636         bool lost;
 637
 638         cip_header[0] = be32_to_cpu(buffer[0]);
 639         cip_header[1] = be32_to_cpu(buffer[1]);
 640
 641         /*
 642          * This module supports 'Two-quadlet CIP header with SYT field'.
 643          * For convenience, also check FMT field is AM824 or not.
 644          */
 645         if (((cip_header[0] & CIP_EOH_MASK) == CIP_EOH) ||
 646             ((cip_header[1] & CIP_EOH_MASK) != CIP_EOH) ||
 647             ((cip_header[1] & CIP_FMT_MASK) != CIP_FMT_AM)) {
 648                 dev_info_ratelimited(&s->unit->device,
 649                                 "Invalid CIP header for AMDTP: %08X:%08X\n",
 650                                 cip_header[0], cip_header[1]);
 651                 goto end;
 652         }
 653
 654         /* Calculate data blocks */
 655         if (payload_quadlets < 3 ||
 656             ((cip_header[1] & CIP_FDF_MASK) ==
 657                                 (AMDTP_FDF_NO_DATA << CIP_FDF_SFC_SHIFT))) {
 658                 data_blocks = 0;
 659         } else {
 660                 data_block_quadlets =
 661                         (cip_header[0] & AMDTP_DBS_MASK) >> AMDTP_DBS_SHIFT;
 662                 /* avoid division by zero */
 663                 if (data_block_quadlets == 0) {
 664                         dev_info_ratelimited(&s->unit->device,
 665                                 "Detect invalid value in dbs field: %08X\n",
 666                                 cip_header[0]);
 667                         goto err;
 668                 }
 669                 if (s->flags & CIP_WRONG_DBS)
 670                         data_block_quadlets = s->data_block_quadlets;
 671
 672                 data_blocks = (payload_quadlets - 2) / data_block_quadlets;
 673         }
 674
 675         /* Check data block counter continuity */
 676         data_block_counter = cip_header[0] & AMDTP_DBC_MASK;
 677         if (data_blocks == 0 && (s->flags & CIP_EMPTY_HAS_WRONG_DBC) &&
 678             s->data_block_counter != UINT_MAX)
 679                 data_block_counter = s->data_block_counter;
 680
 681         if (((s->flags & CIP_SKIP_DBC_ZERO_CHECK) && data_block_counter == 0) ||
 682             (s->data_block_counter == UINT_MAX)) {
 683                 lost = false;
 684         } else if (!(s->flags & CIP_DBC_IS_END_EVENT)) {
 685                 lost = data_block_counter != s->data_block_counter;
 686         } else {
 687                 if ((data_blocks > 0) && (s->tx_dbc_interval > 0))
 688                         dbc_interval = s->tx_dbc_interval;
 689                 else
 690                         dbc_interval = data_blocks;
 691
 692                 lost = data_block_counter !=
 693                        ((s->data_block_counter + dbc_interval) & 0xff);
 694         }
 695
 696         if (lost) {
 697                 dev_info(&s->unit->device,
 698                          "Detect discontinuity of CIP: %02X %02X\n",
 699                          s->data_block_counter, data_block_counter);
 700                 goto err;
 701         }
 702
 703         if (data_blocks > 0) {
 704                 buffer += 2;
 705
 706                 pcm = ACCESS_ONCE(s->pcm);
 707                 if (pcm)
 708                         s->transfer_samples(s, pcm, buffer, data_blocks);
 709
 710                 if (s->midi_ports)
 711                         amdtp_pull_midi(s, buffer, data_blocks);
 712         }
 713
 714         if (s->flags & CIP_DBC_IS_END_EVENT)
 715                 s->data_block_counter = data_block_counter;
 716         else
 717                 s->data_block_counter =
 718                                 (data_block_counter + data_blocks) & 0xff;
 719 end:
 720         if (queue_in_packet(s) < 0)
 721                 goto err;
 722
 723         if (pcm)
 724                 update_pcm_pointers(s, pcm, data_blocks);
 725
 726         return;
 727 err:
 728         s->packet_index = -1;
 729         amdtp_stream_pcm_abort(s);
 730 }
 731
 732 static void out_stream_callback(struct fw_iso_context *context, u32 cycle,
 733                                 size_t header_length, void *header,
 734                                 void *private_data)
 735 {
 736         struct amdtp_stream *s = private_data;
 737         unsigned int i, syt, packets = header_length / 4;
 738
 739         /*
 740          * Compute the cycle of the last queued packet.
 741          * (We need only the four lowest bits for the SYT, so we can ignore
 742          * that bits 0-11 must wrap around at 3072.)
 743          */
 744         cycle += QUEUE_LENGTH - packets;
 745
 746         for (i = 0; i < packets; ++i) {
 747                 syt = calculate_syt(s, ++cycle);
 748                 handle_out_packet(s, syt);
 749         }
 750         fw_iso_context_queue_flush(s->context);
 751 }
 752
 753 static void in_stream_callback(struct fw_iso_context *context, u32 cycle,
 754                                size_t header_length, void *header,
 755                                void *private_data)
 756 {
 757         struct amdtp_stream *s = private_data;
 758         unsigned int p, syt, packets, payload_quadlets;
 759         __be32 *buffer, *headers = header;
 760
 761         /* The number of packets in buffer */
 762         packets = header_length / IN_PACKET_HEADER_SIZE;
 763
 764         for (p = 0; p < packets; p++) {
 765                 if (s->packet_index < 0)
 766                         break;
 767
 768                 buffer = s->buffer.packets[s->packet_index].buffer;
 769
 770                 /* Process sync slave stream */
 771                 if (s->sync_slave && s->sync_slave->callbacked) {
 772                         syt = be32_to_cpu(buffer[1]) & CIP_SYT_MASK;
 773                         handle_out_packet(s->sync_slave, syt);
 774                 }
 775
 776                 /* The number of quadlets in this packet */
 777                 payload_quadlets =
 778                         (be32_to_cpu(headers[p]) >> ISO_DATA_LENGTH_SHIFT) / 4;
 779                 handle_in_packet(s, payload_quadlets, buffer);
 780         }
 781
 782         /* Queueing error or detecting discontinuity */
 783         if (s->packet_index < 0) {
 784                 /* Abort sync slave. */
 785                 if (s->sync_slave) {
 786                         s->sync_slave->packet_index = -1;
 787                         amdtp_stream_pcm_abort(s->sync_slave);
 788                 }
 789                 return;
 790         }
 791
 792         /* when sync to device, flush the packets for slave stream */
 793         if (s->sync_slave && s->sync_slave->callbacked)
 794                 fw_iso_context_queue_flush(s->sync_slave->context);
 795
 796         fw_iso_context_queue_flush(s->context);
 797 }
 798
 799 /* processing is done by master callback */
 800 static void slave_stream_callback(struct fw_iso_context *context, u32 cycle,
 801                                   size_t header_length, void *header,
 802                                   void *private_data)
 803 {
 804         return;
 805 }
 806
 807 /* this is executed one time */
 808 static void amdtp_stream_first_callback(struct fw_iso_context *context,
 809                                         u32 cycle, size_t header_length,
 810                                         void *header, void *private_data)
 811 {
 812         struct amdtp_stream *s = private_data;
 813
 814         /*
 815          * For in-stream, first packet has come.
 816          * For out-stream, prepared to transmit first packet
 817          */
 818         s->callbacked = true;
 819         wake_up(&s->callback_wait);
 820
 821         if (s->direction == AMDTP_IN_STREAM)
 822                 context->callback.sc = in_stream_callback;
 823         else if ((s->flags & CIP_BLOCKING) && (s->flags & CIP_SYNC_TO_DEVICE))
 824                 context->callback.sc = slave_stream_callback;
 825         else
 826                 context->callback.sc = out_stream_callback;
 827
 828         context->callback.sc(context, cycle, header_length, header, s);
 829 }
 830
 831 /**
 832  * amdtp_stream_start - start transferring packets
 833  * @s: the AMDTP stream to start
 834  * @channel: the isochronous channel on the bus
 835  * @speed: firewire speed code
 836  *
 837  * The stream cannot be started until it has been configured with
 838  * amdtp_stream_set_parameters() and it must be started before any PCM or MIDI
 839  * device can be started.
 840  */
 841 int amdtp_stream_start(struct amdtp_stream *s, int channel, int speed)
 842 {
 843         static const struct {
 844                 unsigned int data_block;
 845                 unsigned int syt_offset;
 846         } initial_state[] = {
 847                 [CIP_SFC_32000]  = {  4, 3072 },
 848                 [CIP_SFC_48000]  = {  6, 1024 },
 849                 [CIP_SFC_96000]  = { 12, 1024 },
 850                 [CIP_SFC_192000] = { 24, 1024 },
 851                 [CIP_SFC_44100]  = {  0,   67 },
 852                 [CIP_SFC_88200]  = {  0,   67 },
 853                 [CIP_SFC_176400] = {  0,   67 },
 854         };
 855         unsigned int header_size;
 856         enum dma_data_direction dir;
 857         int type, tag, err;
 858
 859         mutex_lock(&s->mutex);
 860
 861         if (WARN_ON(amdtp_stream_running(s) ||
 862                     (s->data_block_quadlets < 1))) {
 863                 err = -EBADFD;
 864                 goto err_unlock;
 865         }
 866
 867         if (s->direction == AMDTP_IN_STREAM &&
 868             s->flags & CIP_SKIP_INIT_DBC_CHECK)
 869                 s->data_block_counter = UINT_MAX;
 870         else
 871                 s->data_block_counter = 0;
 872         s->data_block_state = initial_state[s->sfc].data_block;
 873         s->syt_offset_state = initial_state[s->sfc].syt_offset;
 874         s->last_syt_offset = TICKS_PER_CYCLE;
 875
 876         /* initialize packet buffer */
 877         if (s->direction == AMDTP_IN_STREAM) {
 878                 dir = DMA_FROM_DEVICE;
 879                 type = FW_ISO_CONTEXT_RECEIVE;
 880                 header_size = IN_PACKET_HEADER_SIZE;
 881         } else {
 882                 dir = DMA_TO_DEVICE;
 883                 type = FW_ISO_CONTEXT_TRANSMIT;
 884                 header_size = OUT_PACKET_HEADER_SIZE;
 885         }
 886         err = iso_packets_buffer_init(&s->buffer, s->unit, QUEUE_LENGTH,
 887                                       amdtp_stream_get_max_payload(s), dir);
 888         if (err < 0)
 889                 goto err_unlock;
 890
 891         s->context = fw_iso_context_create(fw_parent_device(s->unit)->card,
 892                                            type, channel, speed, header_size,
 893                                            amdtp_stream_first_callback, s);
 894         if (IS_ERR(s->context)) {
 895                 err = PTR_ERR(s->context);
 896                 if (err == -EBUSY)
 897                         dev_err(&s->unit->device,
 898                                 "no free stream on this controller\n");
 899                 goto err_buffer;
 900         }
 901
 902         amdtp_stream_update(s);
 903
 904         s->packet_index = 0;
 905         do {
 906                 if (s->direction == AMDTP_IN_STREAM)
 907                         err = queue_in_packet(s);
 908                 else
 909                         err = queue_out_packet(s, 0, true);
 910                 if (err < 0)
 911                         goto err_context;
 912         } while (s->packet_index > 0);
 913
 914         /* NOTE: TAG1 matches CIP. This just affects in stream. */
 915         tag = FW_ISO_CONTEXT_MATCH_TAG1;
 916         if (s->flags & CIP_EMPTY_WITH_TAG0)
 917                 tag |= FW_ISO_CONTEXT_MATCH_TAG0;
 918
 919         s->callbacked = false;
 920         err = fw_iso_context_start(s->context, -1, 0, tag);
 921         if (err < 0)
 922                 goto err_context;
 923
 924         mutex_unlock(&s->mutex);
 925
 926         return 0;
 927
 928 err_context:
 929         fw_iso_context_destroy(s->context);
 930         s->context = ERR_PTR(-1);
 931 err_buffer:
 932         iso_packets_buffer_destroy(&s->buffer, s->unit);
 933 err_unlock:
 934         mutex_unlock(&s->mutex);
 935
 936         return err;
 937 }
 938 EXPORT_SYMBOL(amdtp_stream_start);
 939
 940 /**
 941  * amdtp_stream_pcm_pointer - get the PCM buffer position
 942  * @s: the AMDTP stream that transports the PCM data
 943  *
 944  * Returns the current buffer position, in frames.
 945  */
 946 unsigned long amdtp_stream_pcm_pointer(struct amdtp_stream *s)
 947 {
 948         /* this optimization is allowed to be racy */
 949         if (s->pointer_flush && amdtp_stream_running(s))
 950                 fw_iso_context_flush_completions(s->context);
 951         else
 952                 s->pointer_flush = true;
 953
 954         return ACCESS_ONCE(s->pcm_buffer_pointer);
 955 }
 956 EXPORT_SYMBOL(amdtp_stream_pcm_pointer);
 957
 958 /**
 959  * amdtp_stream_update - update the stream after a bus reset
 960  * @s: the AMDTP stream
 961  */
 962 void amdtp_stream_update(struct amdtp_stream *s)
 963 {
 964         ACCESS_ONCE(s->source_node_id_field) =
 965                 (fw_parent_device(s->unit)->card->node_id & 0x3f) << 24;
 966 }
 967 EXPORT_SYMBOL(amdtp_stream_update);
 968
 969 /**
 970  * amdtp_stream_stop - stop sending packets
 971  * @s: the AMDTP stream to stop
 972  *
 973  * All PCM and MIDI devices of the stream must be stopped before the stream
 974  * itself can be stopped.
 975  */
 976 void amdtp_stream_stop(struct amdtp_stream *s)
 977 {
 978         mutex_lock(&s->mutex);
 979
 980         if (!amdtp_stream_running(s)) {
 981                 mutex_unlock(&s->mutex);
 982                 return;
 983         }
 984
 985         tasklet_kill(&s->period_tasklet);
 986         fw_iso_context_stop(s->context);
 987         fw_iso_context_destroy(s->context);
 988         s->context = ERR_PTR(-1);
 989         iso_packets_buffer_destroy(&s->buffer, s->unit);
 990
 991         s->callbacked = false;
 992
 993         mutex_unlock(&s->mutex);
 994 }
 995 EXPORT_SYMBOL(amdtp_stream_stop);
 996
 997 /**
 998  * amdtp_stream_pcm_abort - abort the running PCM device
 999  * @s: the AMDTP stream about to be stopped
1000  *
1001  * If the isochronous stream needs to be stopped asynchronously, call this
1002  * function first to stop the PCM device.
1003  */
1004 void amdtp_stream_pcm_abort(struct amdtp_stream *s)
1005 {
1006         struct snd_pcm_substream *pcm;
1007
1008         pcm = ACCESS_ONCE(s->pcm);
1009         if (pcm) {
1010                 snd_pcm_stream_lock_irq(pcm);
1011                 if (snd_pcm_running(pcm))
1012                         snd_pcm_stop(pcm, SNDRV_PCM_STATE_XRUN);
1013                 snd_pcm_stream_unlock_irq(pcm);
1014         }
1015 }
1016 EXPORT_SYMBOL(amdtp_stream_pcm_abort);