linux/sound/usb/hiface/pcm.c
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   1/*
   2 * Linux driver for M2Tech hiFace compatible devices
   3 *
   4 * Copyright 2012-2013 (C) M2TECH S.r.l and Amarula Solutions B.V.
   5 *
   6 * Authors:  Michael Trimarchi <michael@amarulasolutions.com>
   7 *           Antonio Ospite <ao2@amarulasolutions.com>
   8 *
   9 * The driver is based on the work done in TerraTec DMX 6Fire USB
  10 *
  11 * This program is free software; you can redistribute it and/or modify
  12 * it under the terms of the GNU General Public License as published by
  13 * the Free Software Foundation; either version 2 of the License, or
  14 * (at your option) any later version.
  15 */
  16
  17#include <linux/slab.h>
  18#include <sound/pcm.h>
  19
  20#include "pcm.h"
  21#include "chip.h"
  22
  23#define OUT_EP          0x2
  24#define PCM_N_URBS      8
  25#define PCM_PACKET_SIZE 4096
  26#define PCM_BUFFER_SIZE (2 * PCM_N_URBS * PCM_PACKET_SIZE)
  27
  28struct pcm_urb {
  29        struct hiface_chip *chip;
  30
  31        struct urb instance;
  32        struct usb_anchor submitted;
  33        u8 *buffer;
  34};
  35
  36struct pcm_substream {
  37        spinlock_t lock;
  38        struct snd_pcm_substream *instance;
  39
  40        bool active;
  41        snd_pcm_uframes_t dma_off;    /* current position in alsa dma_area */
  42        snd_pcm_uframes_t period_off; /* current position in current period */
  43};
  44
  45enum { /* pcm streaming states */
  46        STREAM_DISABLED, /* no pcm streaming */
  47        STREAM_STARTING, /* pcm streaming requested, waiting to become ready */
  48        STREAM_RUNNING,  /* pcm streaming running */
  49        STREAM_STOPPING
  50};
  51
  52struct pcm_runtime {
  53        struct hiface_chip *chip;
  54        struct snd_pcm *instance;
  55
  56        struct pcm_substream playback;
  57        bool panic; /* if set driver won't do anymore pcm on device */
  58
  59        struct pcm_urb out_urbs[PCM_N_URBS];
  60
  61        struct mutex stream_mutex;
  62        u8 stream_state; /* one of STREAM_XXX */
  63        u8 extra_freq;
  64        wait_queue_head_t stream_wait_queue;
  65        bool stream_wait_cond;
  66};
  67
  68static const unsigned int rates[] = { 44100, 48000, 88200, 96000, 176400, 192000,
  69                                      352800, 384000 };
  70static const struct snd_pcm_hw_constraint_list constraints_extra_rates = {
  71        .count = ARRAY_SIZE(rates),
  72        .list = rates,
  73        .mask = 0,
  74};
  75
  76static const struct snd_pcm_hardware pcm_hw = {
  77        .info = SNDRV_PCM_INFO_MMAP |
  78                SNDRV_PCM_INFO_INTERLEAVED |
  79                SNDRV_PCM_INFO_BLOCK_TRANSFER |
  80                SNDRV_PCM_INFO_PAUSE |
  81                SNDRV_PCM_INFO_MMAP_VALID |
  82                SNDRV_PCM_INFO_BATCH,
  83
  84        .formats = SNDRV_PCM_FMTBIT_S32_LE,
  85
  86        .rates = SNDRV_PCM_RATE_44100 |
  87                SNDRV_PCM_RATE_48000 |
  88                SNDRV_PCM_RATE_88200 |
  89                SNDRV_PCM_RATE_96000 |
  90                SNDRV_PCM_RATE_176400 |
  91                SNDRV_PCM_RATE_192000,
  92
  93        .rate_min = 44100,
  94        .rate_max = 192000, /* changes in hiface_pcm_open to support extra rates */
  95        .channels_min = 2,
  96        .channels_max = 2,
  97        .buffer_bytes_max = PCM_BUFFER_SIZE,
  98        .period_bytes_min = PCM_PACKET_SIZE,
  99        .period_bytes_max = PCM_BUFFER_SIZE,
 100        .periods_min = 2,
 101        .periods_max = 1024
 102};
 103
 104/* message values used to change the sample rate */
 105#define HIFACE_SET_RATE_REQUEST 0xb0
 106
 107#define HIFACE_RATE_44100  0x43
 108#define HIFACE_RATE_48000  0x4b
 109#define HIFACE_RATE_88200  0x42
 110#define HIFACE_RATE_96000  0x4a
 111#define HIFACE_RATE_176400 0x40
 112#define HIFACE_RATE_192000 0x48
 113#define HIFACE_RATE_352800 0x58
 114#define HIFACE_RATE_384000 0x68
 115
 116static int hiface_pcm_set_rate(struct pcm_runtime *rt, unsigned int rate)
 117{
 118        struct usb_device *device = rt->chip->dev;
 119        u16 rate_value;
 120        int ret;
 121
 122        /* We are already sure that the rate is supported here thanks to
 123         * ALSA constraints
 124         */
 125        switch (rate) {
 126        case 44100:
 127                rate_value = HIFACE_RATE_44100;
 128                break;
 129        case 48000:
 130                rate_value = HIFACE_RATE_48000;
 131                break;
 132        case 88200:
 133                rate_value = HIFACE_RATE_88200;
 134                break;
 135        case 96000:
 136                rate_value = HIFACE_RATE_96000;
 137                break;
 138        case 176400:
 139                rate_value = HIFACE_RATE_176400;
 140                break;
 141        case 192000:
 142                rate_value = HIFACE_RATE_192000;
 143                break;
 144        case 352800:
 145                rate_value = HIFACE_RATE_352800;
 146                break;
 147        case 384000:
 148                rate_value = HIFACE_RATE_384000;
 149                break;
 150        default:
 151                dev_err(&device->dev, "Unsupported rate %d\n", rate);
 152                return -EINVAL;
 153        }
 154
 155        /*
 156         * USBIO: Vendor 0xb0(wValue=0x0043, wIndex=0x0000)
 157         * 43 b0 43 00 00 00 00 00
 158         * USBIO: Vendor 0xb0(wValue=0x004b, wIndex=0x0000)
 159         * 43 b0 4b 00 00 00 00 00
 160         * This control message doesn't have any ack from the
 161         * other side
 162         */
 163        ret = usb_control_msg(device, usb_sndctrlpipe(device, 0),
 164                              HIFACE_SET_RATE_REQUEST,
 165                              USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_OTHER,
 166                              rate_value, 0, NULL, 0, 100);
 167        if (ret < 0) {
 168                dev_err(&device->dev, "Error setting samplerate %d.\n", rate);
 169                return ret;
 170        }
 171
 172        return 0;
 173}
 174
 175static struct pcm_substream *hiface_pcm_get_substream(struct snd_pcm_substream
 176                                                      *alsa_sub)
 177{
 178        struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
 179        struct device *device = &rt->chip->dev->dev;
 180
 181        if (alsa_sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
 182                return &rt->playback;
 183
 184        dev_err(device, "Error getting pcm substream slot.\n");
 185        return NULL;
 186}
 187
 188/* call with stream_mutex locked */
 189static void hiface_pcm_stream_stop(struct pcm_runtime *rt)
 190{
 191        int i, time;
 192
 193        if (rt->stream_state != STREAM_DISABLED) {
 194                rt->stream_state = STREAM_STOPPING;
 195
 196                for (i = 0; i < PCM_N_URBS; i++) {
 197                        time = usb_wait_anchor_empty_timeout(
 198                                        &rt->out_urbs[i].submitted, 100);
 199                        if (!time)
 200                                usb_kill_anchored_urbs(
 201                                        &rt->out_urbs[i].submitted);
 202                        usb_kill_urb(&rt->out_urbs[i].instance);
 203                }
 204
 205                rt->stream_state = STREAM_DISABLED;
 206        }
 207}
 208
 209/* call with stream_mutex locked */
 210static int hiface_pcm_stream_start(struct pcm_runtime *rt)
 211{
 212        int ret = 0;
 213        int i;
 214
 215        if (rt->stream_state == STREAM_DISABLED) {
 216
 217                /* reset panic state when starting a new stream */
 218                rt->panic = false;
 219
 220                /* submit our out urbs zero init */
 221                rt->stream_state = STREAM_STARTING;
 222                for (i = 0; i < PCM_N_URBS; i++) {
 223                        memset(rt->out_urbs[i].buffer, 0, PCM_PACKET_SIZE);
 224                        usb_anchor_urb(&rt->out_urbs[i].instance,
 225                                       &rt->out_urbs[i].submitted);
 226                        ret = usb_submit_urb(&rt->out_urbs[i].instance,
 227                                             GFP_ATOMIC);
 228                        if (ret) {
 229                                hiface_pcm_stream_stop(rt);
 230                                return ret;
 231                        }
 232                }
 233
 234                /* wait for first out urb to return (sent in in urb handler) */
 235                wait_event_timeout(rt->stream_wait_queue, rt->stream_wait_cond,
 236                                   HZ);
 237                if (rt->stream_wait_cond) {
 238                        struct device *device = &rt->chip->dev->dev;
 239                        dev_dbg(device, "%s: Stream is running wakeup event\n",
 240                                 __func__);
 241                        rt->stream_state = STREAM_RUNNING;
 242                } else {
 243                        hiface_pcm_stream_stop(rt);
 244                        return -EIO;
 245                }
 246        }
 247        return ret;
 248}
 249
 250/* The hardware wants word-swapped 32-bit values */
 251static void memcpy_swahw32(u8 *dest, u8 *src, unsigned int n)
 252{
 253        unsigned int i;
 254
 255        for (i = 0; i < n / 4; i++)
 256                ((u32 *)dest)[i] = swahw32(((u32 *)src)[i]);
 257}
 258
 259/* call with substream locked */
 260/* returns true if a period elapsed */
 261static bool hiface_pcm_playback(struct pcm_substream *sub, struct pcm_urb *urb)
 262{
 263        struct snd_pcm_runtime *alsa_rt = sub->instance->runtime;
 264        struct device *device = &urb->chip->dev->dev;
 265        u8 *source;
 266        unsigned int pcm_buffer_size;
 267
 268        WARN_ON(alsa_rt->format != SNDRV_PCM_FORMAT_S32_LE);
 269
 270        pcm_buffer_size = snd_pcm_lib_buffer_bytes(sub->instance);
 271
 272        if (sub->dma_off + PCM_PACKET_SIZE <= pcm_buffer_size) {
 273                dev_dbg(device, "%s: (1) buffer_size %#x dma_offset %#x\n", __func__,
 274                         (unsigned int) pcm_buffer_size,
 275                         (unsigned int) sub->dma_off);
 276
 277                source = alsa_rt->dma_area + sub->dma_off;
 278                memcpy_swahw32(urb->buffer, source, PCM_PACKET_SIZE);
 279        } else {
 280                /* wrap around at end of ring buffer */
 281                unsigned int len;
 282
 283                dev_dbg(device, "%s: (2) buffer_size %#x dma_offset %#x\n", __func__,
 284                         (unsigned int) pcm_buffer_size,
 285                         (unsigned int) sub->dma_off);
 286
 287                len = pcm_buffer_size - sub->dma_off;
 288
 289                source = alsa_rt->dma_area + sub->dma_off;
 290                memcpy_swahw32(urb->buffer, source, len);
 291
 292                source = alsa_rt->dma_area;
 293                memcpy_swahw32(urb->buffer + len, source,
 294                               PCM_PACKET_SIZE - len);
 295        }
 296        sub->dma_off += PCM_PACKET_SIZE;
 297        if (sub->dma_off >= pcm_buffer_size)
 298                sub->dma_off -= pcm_buffer_size;
 299
 300        sub->period_off += PCM_PACKET_SIZE;
 301        if (sub->period_off >= alsa_rt->period_size) {
 302                sub->period_off %= alsa_rt->period_size;
 303                return true;
 304        }
 305        return false;
 306}
 307
 308static void hiface_pcm_out_urb_handler(struct urb *usb_urb)
 309{
 310        struct pcm_urb *out_urb = usb_urb->context;
 311        struct pcm_runtime *rt = out_urb->chip->pcm;
 312        struct pcm_substream *sub;
 313        bool do_period_elapsed = false;
 314        unsigned long flags;
 315        int ret;
 316
 317        if (rt->panic || rt->stream_state == STREAM_STOPPING)
 318                return;
 319
 320        if (unlikely(usb_urb->status == -ENOENT ||      /* unlinked */
 321                     usb_urb->status == -ENODEV ||      /* device removed */
 322                     usb_urb->status == -ECONNRESET ||  /* unlinked */
 323                     usb_urb->status == -ESHUTDOWN)) {  /* device disabled */
 324                goto out_fail;
 325        }
 326
 327        if (rt->stream_state == STREAM_STARTING) {
 328                rt->stream_wait_cond = true;
 329                wake_up(&rt->stream_wait_queue);
 330        }
 331
 332        /* now send our playback data (if a free out urb was found) */
 333        sub = &rt->playback;
 334        spin_lock_irqsave(&sub->lock, flags);
 335        if (sub->active)
 336                do_period_elapsed = hiface_pcm_playback(sub, out_urb);
 337        else
 338                memset(out_urb->buffer, 0, PCM_PACKET_SIZE);
 339
 340        spin_unlock_irqrestore(&sub->lock, flags);
 341
 342        if (do_period_elapsed)
 343                snd_pcm_period_elapsed(sub->instance);
 344
 345        ret = usb_submit_urb(&out_urb->instance, GFP_ATOMIC);
 346        if (ret < 0)
 347                goto out_fail;
 348
 349        return;
 350
 351out_fail:
 352        rt->panic = true;
 353}
 354
 355static int hiface_pcm_open(struct snd_pcm_substream *alsa_sub)
 356{
 357        struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
 358        struct pcm_substream *sub = NULL;
 359        struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
 360        int ret;
 361
 362        if (rt->panic)
 363                return -EPIPE;
 364
 365        mutex_lock(&rt->stream_mutex);
 366        alsa_rt->hw = pcm_hw;
 367
 368        if (alsa_sub->stream == SNDRV_PCM_STREAM_PLAYBACK)
 369                sub = &rt->playback;
 370
 371        if (!sub) {
 372                struct device *device = &rt->chip->dev->dev;
 373                mutex_unlock(&rt->stream_mutex);
 374                dev_err(device, "Invalid stream type\n");
 375                return -EINVAL;
 376        }
 377
 378        if (rt->extra_freq) {
 379                alsa_rt->hw.rates |= SNDRV_PCM_RATE_KNOT;
 380                alsa_rt->hw.rate_max = 384000;
 381
 382                /* explicit constraints needed as we added SNDRV_PCM_RATE_KNOT */
 383                ret = snd_pcm_hw_constraint_list(alsa_sub->runtime, 0,
 384                                                 SNDRV_PCM_HW_PARAM_RATE,
 385                                                 &constraints_extra_rates);
 386                if (ret < 0) {
 387                        mutex_unlock(&rt->stream_mutex);
 388                        return ret;
 389                }
 390        }
 391
 392        sub->instance = alsa_sub;
 393        sub->active = false;
 394        mutex_unlock(&rt->stream_mutex);
 395        return 0;
 396}
 397
 398static int hiface_pcm_close(struct snd_pcm_substream *alsa_sub)
 399{
 400        struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
 401        struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
 402        unsigned long flags;
 403
 404        if (rt->panic)
 405                return 0;
 406
 407        mutex_lock(&rt->stream_mutex);
 408        if (sub) {
 409                hiface_pcm_stream_stop(rt);
 410
 411                /* deactivate substream */
 412                spin_lock_irqsave(&sub->lock, flags);
 413                sub->instance = NULL;
 414                sub->active = false;
 415                spin_unlock_irqrestore(&sub->lock, flags);
 416
 417        }
 418        mutex_unlock(&rt->stream_mutex);
 419        return 0;
 420}
 421
 422static int hiface_pcm_hw_params(struct snd_pcm_substream *alsa_sub,
 423                                struct snd_pcm_hw_params *hw_params)
 424{
 425        return snd_pcm_lib_alloc_vmalloc_buffer(alsa_sub,
 426                                                params_buffer_bytes(hw_params));
 427}
 428
 429static int hiface_pcm_hw_free(struct snd_pcm_substream *alsa_sub)
 430{
 431        return snd_pcm_lib_free_vmalloc_buffer(alsa_sub);
 432}
 433
 434static int hiface_pcm_prepare(struct snd_pcm_substream *alsa_sub)
 435{
 436        struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
 437        struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
 438        struct snd_pcm_runtime *alsa_rt = alsa_sub->runtime;
 439        int ret;
 440
 441        if (rt->panic)
 442                return -EPIPE;
 443        if (!sub)
 444                return -ENODEV;
 445
 446        mutex_lock(&rt->stream_mutex);
 447
 448        hiface_pcm_stream_stop(rt);
 449
 450        sub->dma_off = 0;
 451        sub->period_off = 0;
 452
 453        if (rt->stream_state == STREAM_DISABLED) {
 454
 455                ret = hiface_pcm_set_rate(rt, alsa_rt->rate);
 456                if (ret) {
 457                        mutex_unlock(&rt->stream_mutex);
 458                        return ret;
 459                }
 460                ret = hiface_pcm_stream_start(rt);
 461                if (ret) {
 462                        mutex_unlock(&rt->stream_mutex);
 463                        return ret;
 464                }
 465        }
 466        mutex_unlock(&rt->stream_mutex);
 467        return 0;
 468}
 469
 470static int hiface_pcm_trigger(struct snd_pcm_substream *alsa_sub, int cmd)
 471{
 472        struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
 473        struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
 474
 475        if (rt->panic)
 476                return -EPIPE;
 477        if (!sub)
 478                return -ENODEV;
 479
 480        switch (cmd) {
 481        case SNDRV_PCM_TRIGGER_START:
 482        case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 483                spin_lock_irq(&sub->lock);
 484                sub->active = true;
 485                spin_unlock_irq(&sub->lock);
 486                return 0;
 487
 488        case SNDRV_PCM_TRIGGER_STOP:
 489        case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 490                spin_lock_irq(&sub->lock);
 491                sub->active = false;
 492                spin_unlock_irq(&sub->lock);
 493                return 0;
 494
 495        default:
 496                return -EINVAL;
 497        }
 498}
 499
 500static snd_pcm_uframes_t hiface_pcm_pointer(struct snd_pcm_substream *alsa_sub)
 501{
 502        struct pcm_substream *sub = hiface_pcm_get_substream(alsa_sub);
 503        struct pcm_runtime *rt = snd_pcm_substream_chip(alsa_sub);
 504        unsigned long flags;
 505        snd_pcm_uframes_t dma_offset;
 506
 507        if (rt->panic || !sub)
 508                return SNDRV_PCM_POS_XRUN;
 509
 510        spin_lock_irqsave(&sub->lock, flags);
 511        dma_offset = sub->dma_off;
 512        spin_unlock_irqrestore(&sub->lock, flags);
 513        return bytes_to_frames(alsa_sub->runtime, dma_offset);
 514}
 515
 516static const struct snd_pcm_ops pcm_ops = {
 517        .open = hiface_pcm_open,
 518        .close = hiface_pcm_close,
 519        .ioctl = snd_pcm_lib_ioctl,
 520        .hw_params = hiface_pcm_hw_params,
 521        .hw_free = hiface_pcm_hw_free,
 522        .prepare = hiface_pcm_prepare,
 523        .trigger = hiface_pcm_trigger,
 524        .pointer = hiface_pcm_pointer,
 525        .page = snd_pcm_lib_get_vmalloc_page,
 526        .mmap = snd_pcm_lib_mmap_vmalloc,
 527};
 528
 529static int hiface_pcm_init_urb(struct pcm_urb *urb,
 530                               struct hiface_chip *chip,
 531                               unsigned int ep,
 532                               void (*handler)(struct urb *))
 533{
 534        urb->chip = chip;
 535        usb_init_urb(&urb->instance);
 536
 537        urb->buffer = kzalloc(PCM_PACKET_SIZE, GFP_KERNEL);
 538        if (!urb->buffer)
 539                return -ENOMEM;
 540
 541        usb_fill_bulk_urb(&urb->instance, chip->dev,
 542                          usb_sndbulkpipe(chip->dev, ep), (void *)urb->buffer,
 543                          PCM_PACKET_SIZE, handler, urb);
 544        if (usb_urb_ep_type_check(&urb->instance))
 545                return -EINVAL;
 546        init_usb_anchor(&urb->submitted);
 547
 548        return 0;
 549}
 550
 551void hiface_pcm_abort(struct hiface_chip *chip)
 552{
 553        struct pcm_runtime *rt = chip->pcm;
 554
 555        if (rt) {
 556                rt->panic = true;
 557
 558                mutex_lock(&rt->stream_mutex);
 559                hiface_pcm_stream_stop(rt);
 560                mutex_unlock(&rt->stream_mutex);
 561        }
 562}
 563
 564static void hiface_pcm_destroy(struct hiface_chip *chip)
 565{
 566        struct pcm_runtime *rt = chip->pcm;
 567        int i;
 568
 569        for (i = 0; i < PCM_N_URBS; i++)
 570                kfree(rt->out_urbs[i].buffer);
 571
 572        kfree(chip->pcm);
 573        chip->pcm = NULL;
 574}
 575
 576static void hiface_pcm_free(struct snd_pcm *pcm)
 577{
 578        struct pcm_runtime *rt = pcm->private_data;
 579
 580        if (rt)
 581                hiface_pcm_destroy(rt->chip);
 582}
 583
 584int hiface_pcm_init(struct hiface_chip *chip, u8 extra_freq)
 585{
 586        int i;
 587        int ret;
 588        struct snd_pcm *pcm;
 589        struct pcm_runtime *rt;
 590
 591        rt = kzalloc(sizeof(*rt), GFP_KERNEL);
 592        if (!rt)
 593                return -ENOMEM;
 594
 595        rt->chip = chip;
 596        rt->stream_state = STREAM_DISABLED;
 597        if (extra_freq)
 598                rt->extra_freq = 1;
 599
 600        init_waitqueue_head(&rt->stream_wait_queue);
 601        mutex_init(&rt->stream_mutex);
 602        spin_lock_init(&rt->playback.lock);
 603
 604        for (i = 0; i < PCM_N_URBS; i++) {
 605                ret = hiface_pcm_init_urb(&rt->out_urbs[i], chip, OUT_EP,
 606                                    hiface_pcm_out_urb_handler);
 607                if (ret < 0)
 608                        return ret;
 609        }
 610
 611        ret = snd_pcm_new(chip->card, "USB-SPDIF Audio", 0, 1, 0, &pcm);
 612        if (ret < 0) {
 613                kfree(rt);
 614                dev_err(&chip->dev->dev, "Cannot create pcm instance\n");
 615                return ret;
 616        }
 617
 618        pcm->private_data = rt;
 619        pcm->private_free = hiface_pcm_free;
 620
 621        strlcpy(pcm->name, "USB-SPDIF Audio", sizeof(pcm->name));
 622        snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_PLAYBACK, &pcm_ops);
 623
 624        rt->instance = pcm;
 625
 626        chip->pcm = rt;
 627        return 0;
 628}
 629