linux/sound/firewire/motu/amdtp-motu.c
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   1/*
   2 * amdtp-motu.c - a part of driver for MOTU FireWire series
   3 *
   4 * Copyright (c) 2015-2017 Takashi Sakamoto <o-takashi@sakamocchi.jp>
   5 *
   6 * Licensed under the terms of the GNU General Public License, version 2.
   7 */
   8
   9#include <linux/slab.h>
  10#include <sound/pcm.h>
  11#include "motu.h"
  12
  13#define CREATE_TRACE_POINTS
  14#include "amdtp-motu-trace.h"
  15
  16#define CIP_FMT_MOTU            0x02
  17#define CIP_FMT_MOTU_TX_V3      0x22
  18#define MOTU_FDF_AM824          0x22
  19
  20/*
  21 * Nominally 3125 bytes/second, but the MIDI port's clock might be
  22 * 1% too slow, and the bus clock 100 ppm too fast.
  23 */
  24#define MIDI_BYTES_PER_SECOND   3093
  25
  26struct amdtp_motu {
  27        /* For timestamp processing.  */
  28        unsigned int quotient_ticks_per_event;
  29        unsigned int remainder_ticks_per_event;
  30        unsigned int next_ticks;
  31        unsigned int next_accumulated;
  32        unsigned int next_cycles;
  33        unsigned int next_seconds;
  34
  35        unsigned int pcm_chunks;
  36        unsigned int pcm_byte_offset;
  37
  38        struct snd_rawmidi_substream *midi;
  39        unsigned int midi_ports;
  40        unsigned int midi_flag_offset;
  41        unsigned int midi_byte_offset;
  42
  43        int midi_db_count;
  44        unsigned int midi_db_interval;
  45};
  46
  47int amdtp_motu_set_parameters(struct amdtp_stream *s, unsigned int rate,
  48                              unsigned int midi_ports,
  49                              struct snd_motu_packet_format *formats)
  50{
  51        static const struct {
  52                unsigned int quotient_ticks_per_event;
  53                unsigned int remainder_ticks_per_event;
  54        } params[] = {
  55                [CIP_SFC_44100]  = { 557, 123 },
  56                [CIP_SFC_48000]  = { 512,   0 },
  57                [CIP_SFC_88200]  = { 278, 282 },
  58                [CIP_SFC_96000]  = { 256,   0 },
  59                [CIP_SFC_176400] = { 139, 141 },
  60                [CIP_SFC_192000] = { 128,   0 },
  61        };
  62        struct amdtp_motu *p = s->protocol;
  63        unsigned int pcm_chunks, data_chunks, data_block_quadlets;
  64        unsigned int delay;
  65        unsigned int mode;
  66        int i, err;
  67
  68        if (amdtp_stream_running(s))
  69                return -EBUSY;
  70
  71        for (i = 0; i < ARRAY_SIZE(snd_motu_clock_rates); ++i) {
  72                if (snd_motu_clock_rates[i] == rate) {
  73                        mode = i >> 1;
  74                        break;
  75                }
  76        }
  77        if (i == ARRAY_SIZE(snd_motu_clock_rates))
  78                return -EINVAL;
  79
  80        pcm_chunks = formats->fixed_part_pcm_chunks[mode] +
  81                     formats->differed_part_pcm_chunks[mode];
  82        data_chunks = formats->msg_chunks + pcm_chunks;
  83
  84        /*
  85         * Each data block includes SPH in its head. Data chunks follow with
  86         * 3 byte alignment. Padding follows with zero to conform to quadlet
  87         * alignment.
  88         */
  89        data_block_quadlets = 1 + DIV_ROUND_UP(data_chunks * 3, 4);
  90
  91        err = amdtp_stream_set_parameters(s, rate, data_block_quadlets);
  92        if (err < 0)
  93                return err;
  94
  95        p->pcm_chunks = pcm_chunks;
  96        p->pcm_byte_offset = formats->pcm_byte_offset;
  97
  98        p->midi_ports = midi_ports;
  99        p->midi_flag_offset = formats->midi_flag_offset;
 100        p->midi_byte_offset = formats->midi_byte_offset;
 101
 102        p->midi_db_count = 0;
 103        p->midi_db_interval = rate / MIDI_BYTES_PER_SECOND;
 104
 105        /* IEEE 1394 bus requires. */
 106        delay = 0x2e00;
 107
 108        /* For no-data or empty packets to adjust PCM sampling frequency. */
 109        delay += 8000 * 3072 * s->syt_interval / rate;
 110
 111        p->next_seconds = 0;
 112        p->next_cycles = delay / 3072;
 113        p->quotient_ticks_per_event = params[s->sfc].quotient_ticks_per_event;
 114        p->remainder_ticks_per_event = params[s->sfc].remainder_ticks_per_event;
 115        p->next_ticks = delay % 3072;
 116        p->next_accumulated = 0;
 117
 118        return 0;
 119}
 120
 121static void read_pcm_s32(struct amdtp_stream *s,
 122                         struct snd_pcm_runtime *runtime,
 123                         __be32 *buffer, unsigned int data_blocks)
 124{
 125        struct amdtp_motu *p = s->protocol;
 126        unsigned int channels, remaining_frames, i, c;
 127        u8 *byte;
 128        u32 *dst;
 129
 130        channels = p->pcm_chunks;
 131        dst = (void *)runtime->dma_area +
 132                        frames_to_bytes(runtime, s->pcm_buffer_pointer);
 133        remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
 134
 135        for (i = 0; i < data_blocks; ++i) {
 136                byte = (u8 *)buffer + p->pcm_byte_offset;
 137
 138                for (c = 0; c < channels; ++c) {
 139                        *dst = (byte[0] << 24) | (byte[1] << 16) | byte[2];
 140                        byte += 3;
 141                        dst++;
 142                }
 143                buffer += s->data_block_quadlets;
 144                if (--remaining_frames == 0)
 145                        dst = (void *)runtime->dma_area;
 146        }
 147}
 148
 149static void write_pcm_s32(struct amdtp_stream *s,
 150                          struct snd_pcm_runtime *runtime,
 151                          __be32 *buffer, unsigned int data_blocks)
 152{
 153        struct amdtp_motu *p = s->protocol;
 154        unsigned int channels, remaining_frames, i, c;
 155        u8 *byte;
 156        const u32 *src;
 157
 158        channels = p->pcm_chunks;
 159        src = (void *)runtime->dma_area +
 160                        frames_to_bytes(runtime, s->pcm_buffer_pointer);
 161        remaining_frames = runtime->buffer_size - s->pcm_buffer_pointer;
 162
 163        for (i = 0; i < data_blocks; ++i) {
 164                byte = (u8 *)buffer + p->pcm_byte_offset;
 165
 166                for (c = 0; c < channels; ++c) {
 167                        byte[0] = (*src >> 24) & 0xff;
 168                        byte[1] = (*src >> 16) & 0xff;
 169                        byte[2] = (*src >>  8) & 0xff;
 170                        byte += 3;
 171                        src++;
 172                }
 173
 174                buffer += s->data_block_quadlets;
 175                if (--remaining_frames == 0)
 176                        src = (void *)runtime->dma_area;
 177        }
 178}
 179
 180static void write_pcm_silence(struct amdtp_stream *s, __be32 *buffer,
 181                              unsigned int data_blocks)
 182{
 183        struct amdtp_motu *p = s->protocol;
 184        unsigned int channels, i, c;
 185        u8 *byte;
 186
 187        channels = p->pcm_chunks;
 188
 189        for (i = 0; i < data_blocks; ++i) {
 190                byte = (u8 *)buffer + p->pcm_byte_offset;
 191
 192                for (c = 0; c < channels; ++c) {
 193                        byte[0] = 0;
 194                        byte[1] = 0;
 195                        byte[2] = 0;
 196                        byte += 3;
 197                }
 198
 199                buffer += s->data_block_quadlets;
 200        }
 201}
 202
 203int amdtp_motu_add_pcm_hw_constraints(struct amdtp_stream *s,
 204                                      struct snd_pcm_runtime *runtime)
 205{
 206        int err;
 207
 208        /* TODO: how to set an constraint for exactly 24bit PCM sample? */
 209        err = snd_pcm_hw_constraint_msbits(runtime, 0, 32, 24);
 210        if (err < 0)
 211                return err;
 212
 213        return amdtp_stream_add_pcm_hw_constraints(s, runtime);
 214}
 215
 216void amdtp_motu_midi_trigger(struct amdtp_stream *s, unsigned int port,
 217                             struct snd_rawmidi_substream *midi)
 218{
 219        struct amdtp_motu *p = s->protocol;
 220
 221        if (port < p->midi_ports)
 222                WRITE_ONCE(p->midi, midi);
 223}
 224
 225static void write_midi_messages(struct amdtp_stream *s, __be32 *buffer,
 226                                unsigned int data_blocks)
 227{
 228        struct amdtp_motu *p = s->protocol;
 229        struct snd_rawmidi_substream *midi = READ_ONCE(p->midi);
 230        u8 *b;
 231        int i;
 232
 233        for (i = 0; i < data_blocks; i++) {
 234                b = (u8 *)buffer;
 235
 236                if (midi && p->midi_db_count == 0 &&
 237                    snd_rawmidi_transmit(midi, b + p->midi_byte_offset, 1) == 1) {
 238                        b[p->midi_flag_offset] = 0x01;
 239                } else {
 240                        b[p->midi_byte_offset] = 0x00;
 241                        b[p->midi_flag_offset] = 0x00;
 242                }
 243
 244                buffer += s->data_block_quadlets;
 245
 246                if (--p->midi_db_count < 0)
 247                        p->midi_db_count = p->midi_db_interval;
 248        }
 249}
 250
 251static void read_midi_messages(struct amdtp_stream *s, __be32 *buffer,
 252                               unsigned int data_blocks)
 253{
 254        struct amdtp_motu *p = s->protocol;
 255        struct snd_rawmidi_substream *midi;
 256        u8 *b;
 257        int i;
 258
 259        for (i = 0; i < data_blocks; i++) {
 260                b = (u8 *)buffer;
 261                midi = READ_ONCE(p->midi);
 262
 263                if (midi && (b[p->midi_flag_offset] & 0x01))
 264                        snd_rawmidi_receive(midi, b + p->midi_byte_offset, 1);
 265
 266                buffer += s->data_block_quadlets;
 267        }
 268}
 269
 270/* For tracepoints. */
 271static void __maybe_unused copy_sph(u32 *frames, __be32 *buffer,
 272                                    unsigned int data_blocks,
 273                                    unsigned int data_block_quadlets)
 274{
 275        unsigned int i;
 276
 277        for (i = 0; i < data_blocks; ++i) {
 278                *frames = be32_to_cpu(*buffer);
 279                buffer += data_block_quadlets;
 280                frames++;
 281        }
 282}
 283
 284/* For tracepoints. */
 285static void __maybe_unused copy_message(u64 *frames, __be32 *buffer,
 286                                        unsigned int data_blocks,
 287                                        unsigned int data_block_quadlets)
 288{
 289        unsigned int i;
 290
 291        /* This is just for v2/v3 protocol. */
 292        for (i = 0; i < data_blocks; ++i) {
 293                *frames = (be32_to_cpu(buffer[1]) << 16) |
 294                          (be32_to_cpu(buffer[2]) >> 16);
 295                buffer += data_block_quadlets;
 296                frames++;
 297        }
 298}
 299
 300static unsigned int process_tx_data_blocks(struct amdtp_stream *s,
 301                                __be32 *buffer, unsigned int data_blocks,
 302                                unsigned int *syt)
 303{
 304        struct amdtp_motu *p = s->protocol;
 305        struct snd_pcm_substream *pcm;
 306
 307        trace_in_data_block_sph(s, data_blocks, buffer);
 308        trace_in_data_block_message(s, data_blocks, buffer);
 309
 310        if (p->midi_ports)
 311                read_midi_messages(s, buffer, data_blocks);
 312
 313        pcm = READ_ONCE(s->pcm);
 314        if (data_blocks > 0 && pcm)
 315                read_pcm_s32(s, pcm->runtime, buffer, data_blocks);
 316
 317        return data_blocks;
 318}
 319
 320static inline void compute_next_elapse_from_start(struct amdtp_motu *p)
 321{
 322        p->next_accumulated += p->remainder_ticks_per_event;
 323        if (p->next_accumulated >= 441) {
 324                p->next_accumulated -= 441;
 325                p->next_ticks++;
 326        }
 327
 328        p->next_ticks += p->quotient_ticks_per_event;
 329        if (p->next_ticks >= 3072) {
 330                p->next_ticks -= 3072;
 331                p->next_cycles++;
 332        }
 333
 334        if (p->next_cycles >= 8000) {
 335                p->next_cycles -= 8000;
 336                p->next_seconds++;
 337        }
 338
 339        if (p->next_seconds >= 128)
 340                p->next_seconds -= 128;
 341}
 342
 343static void write_sph(struct amdtp_stream *s, __be32 *buffer,
 344                      unsigned int data_blocks)
 345{
 346        struct amdtp_motu *p = s->protocol;
 347        unsigned int next_cycles;
 348        unsigned int i;
 349        u32 sph;
 350
 351        for (i = 0; i < data_blocks; i++) {
 352                next_cycles = (s->start_cycle + p->next_cycles) % 8000;
 353                sph = ((next_cycles << 12) | p->next_ticks) & 0x01ffffff;
 354                *buffer = cpu_to_be32(sph);
 355
 356                compute_next_elapse_from_start(p);
 357
 358                buffer += s->data_block_quadlets;
 359        }
 360}
 361
 362static unsigned int process_rx_data_blocks(struct amdtp_stream *s,
 363                                __be32 *buffer, unsigned int data_blocks,
 364                                unsigned int *syt)
 365{
 366        struct amdtp_motu *p = (struct amdtp_motu *)s->protocol;
 367        struct snd_pcm_substream *pcm;
 368
 369        /* Not used. */
 370        *syt = 0xffff;
 371
 372        /* TODO: how to interact control messages between userspace? */
 373
 374        if (p->midi_ports)
 375                write_midi_messages(s, buffer, data_blocks);
 376
 377        pcm = READ_ONCE(s->pcm);
 378        if (pcm)
 379                write_pcm_s32(s, pcm->runtime, buffer, data_blocks);
 380        else
 381                write_pcm_silence(s, buffer, data_blocks);
 382
 383        write_sph(s, buffer, data_blocks);
 384
 385        trace_out_data_block_sph(s, data_blocks, buffer);
 386        trace_out_data_block_message(s, data_blocks, buffer);
 387
 388        return data_blocks;
 389}
 390
 391int amdtp_motu_init(struct amdtp_stream *s, struct fw_unit *unit,
 392                    enum amdtp_stream_direction dir,
 393                    const struct snd_motu_protocol *const protocol)
 394{
 395        amdtp_stream_process_data_blocks_t process_data_blocks;
 396        int fmt = CIP_FMT_MOTU;
 397        int flags = CIP_BLOCKING;
 398        int err;
 399
 400        if (dir == AMDTP_IN_STREAM) {
 401                process_data_blocks = process_tx_data_blocks;
 402
 403                /*
 404                 * Units of version 3 transmits packets with invalid CIP header
 405                 * against IEC 61883-1.
 406                 */
 407                if (protocol == &snd_motu_protocol_v3) {
 408                        flags |= CIP_WRONG_DBS |
 409                                 CIP_SKIP_DBC_ZERO_CHECK |
 410                                 CIP_HEADER_WITHOUT_EOH;
 411                        fmt = CIP_FMT_MOTU_TX_V3;
 412                }
 413        } else {
 414                process_data_blocks = process_rx_data_blocks;
 415                flags |= CIP_DBC_IS_END_EVENT;
 416        }
 417
 418        err = amdtp_stream_init(s, unit, dir, flags, fmt, process_data_blocks,
 419                                sizeof(struct amdtp_motu));
 420        if (err < 0)
 421                return err;
 422
 423        s->sph = 1;
 424        s->fdf = MOTU_FDF_AM824;
 425
 426        return 0;
 427}
 428