linux/sound/virtio/virtio_pcm.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * virtio-snd: Virtio sound device
   4 * Copyright (C) 2021 OpenSynergy GmbH
   5 */
   6#include <linux/moduleparam.h>
   7#include <linux/virtio_config.h>
   8
   9#include "virtio_card.h"
  10
  11static u32 pcm_buffer_ms = 160;
  12module_param(pcm_buffer_ms, uint, 0644);
  13MODULE_PARM_DESC(pcm_buffer_ms, "PCM substream buffer time in milliseconds");
  14
  15static u32 pcm_periods_min = 2;
  16module_param(pcm_periods_min, uint, 0644);
  17MODULE_PARM_DESC(pcm_periods_min, "Minimum number of PCM periods");
  18
  19static u32 pcm_periods_max = 16;
  20module_param(pcm_periods_max, uint, 0644);
  21MODULE_PARM_DESC(pcm_periods_max, "Maximum number of PCM periods");
  22
  23static u32 pcm_period_ms_min = 10;
  24module_param(pcm_period_ms_min, uint, 0644);
  25MODULE_PARM_DESC(pcm_period_ms_min, "Minimum PCM period time in milliseconds");
  26
  27static u32 pcm_period_ms_max = 80;
  28module_param(pcm_period_ms_max, uint, 0644);
  29MODULE_PARM_DESC(pcm_period_ms_max, "Maximum PCM period time in milliseconds");
  30
  31/* Map for converting VirtIO format to ALSA format. */
  32static const snd_pcm_format_t g_v2a_format_map[] = {
  33        [VIRTIO_SND_PCM_FMT_IMA_ADPCM] = SNDRV_PCM_FORMAT_IMA_ADPCM,
  34        [VIRTIO_SND_PCM_FMT_MU_LAW] = SNDRV_PCM_FORMAT_MU_LAW,
  35        [VIRTIO_SND_PCM_FMT_A_LAW] = SNDRV_PCM_FORMAT_A_LAW,
  36        [VIRTIO_SND_PCM_FMT_S8] = SNDRV_PCM_FORMAT_S8,
  37        [VIRTIO_SND_PCM_FMT_U8] = SNDRV_PCM_FORMAT_U8,
  38        [VIRTIO_SND_PCM_FMT_S16] = SNDRV_PCM_FORMAT_S16_LE,
  39        [VIRTIO_SND_PCM_FMT_U16] = SNDRV_PCM_FORMAT_U16_LE,
  40        [VIRTIO_SND_PCM_FMT_S18_3] = SNDRV_PCM_FORMAT_S18_3LE,
  41        [VIRTIO_SND_PCM_FMT_U18_3] = SNDRV_PCM_FORMAT_U18_3LE,
  42        [VIRTIO_SND_PCM_FMT_S20_3] = SNDRV_PCM_FORMAT_S20_3LE,
  43        [VIRTIO_SND_PCM_FMT_U20_3] = SNDRV_PCM_FORMAT_U20_3LE,
  44        [VIRTIO_SND_PCM_FMT_S24_3] = SNDRV_PCM_FORMAT_S24_3LE,
  45        [VIRTIO_SND_PCM_FMT_U24_3] = SNDRV_PCM_FORMAT_U24_3LE,
  46        [VIRTIO_SND_PCM_FMT_S20] = SNDRV_PCM_FORMAT_S20_LE,
  47        [VIRTIO_SND_PCM_FMT_U20] = SNDRV_PCM_FORMAT_U20_LE,
  48        [VIRTIO_SND_PCM_FMT_S24] = SNDRV_PCM_FORMAT_S24_LE,
  49        [VIRTIO_SND_PCM_FMT_U24] = SNDRV_PCM_FORMAT_U24_LE,
  50        [VIRTIO_SND_PCM_FMT_S32] = SNDRV_PCM_FORMAT_S32_LE,
  51        [VIRTIO_SND_PCM_FMT_U32] = SNDRV_PCM_FORMAT_U32_LE,
  52        [VIRTIO_SND_PCM_FMT_FLOAT] = SNDRV_PCM_FORMAT_FLOAT_LE,
  53        [VIRTIO_SND_PCM_FMT_FLOAT64] = SNDRV_PCM_FORMAT_FLOAT64_LE,
  54        [VIRTIO_SND_PCM_FMT_DSD_U8] = SNDRV_PCM_FORMAT_DSD_U8,
  55        [VIRTIO_SND_PCM_FMT_DSD_U16] = SNDRV_PCM_FORMAT_DSD_U16_LE,
  56        [VIRTIO_SND_PCM_FMT_DSD_U32] = SNDRV_PCM_FORMAT_DSD_U32_LE,
  57        [VIRTIO_SND_PCM_FMT_IEC958_SUBFRAME] =
  58                SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE
  59};
  60
  61/* Map for converting VirtIO frame rate to ALSA frame rate. */
  62struct virtsnd_v2a_rate {
  63        unsigned int alsa_bit;
  64        unsigned int rate;
  65};
  66
  67static const struct virtsnd_v2a_rate g_v2a_rate_map[] = {
  68        [VIRTIO_SND_PCM_RATE_5512] = { SNDRV_PCM_RATE_5512, 5512 },
  69        [VIRTIO_SND_PCM_RATE_8000] = { SNDRV_PCM_RATE_8000, 8000 },
  70        [VIRTIO_SND_PCM_RATE_11025] = { SNDRV_PCM_RATE_11025, 11025 },
  71        [VIRTIO_SND_PCM_RATE_16000] = { SNDRV_PCM_RATE_16000, 16000 },
  72        [VIRTIO_SND_PCM_RATE_22050] = { SNDRV_PCM_RATE_22050, 22050 },
  73        [VIRTIO_SND_PCM_RATE_32000] = { SNDRV_PCM_RATE_32000, 32000 },
  74        [VIRTIO_SND_PCM_RATE_44100] = { SNDRV_PCM_RATE_44100, 44100 },
  75        [VIRTIO_SND_PCM_RATE_48000] = { SNDRV_PCM_RATE_48000, 48000 },
  76        [VIRTIO_SND_PCM_RATE_64000] = { SNDRV_PCM_RATE_64000, 64000 },
  77        [VIRTIO_SND_PCM_RATE_88200] = { SNDRV_PCM_RATE_88200, 88200 },
  78        [VIRTIO_SND_PCM_RATE_96000] = { SNDRV_PCM_RATE_96000, 96000 },
  79        [VIRTIO_SND_PCM_RATE_176400] = { SNDRV_PCM_RATE_176400, 176400 },
  80        [VIRTIO_SND_PCM_RATE_192000] = { SNDRV_PCM_RATE_192000, 192000 }
  81};
  82
  83/**
  84 * virtsnd_pcm_build_hw() - Parse substream config and build HW descriptor.
  85 * @vss: VirtIO substream.
  86 * @info: VirtIO substream information entry.
  87 *
  88 * Context: Any context.
  89 * Return: 0 on success, -EINVAL if configuration is invalid.
  90 */
  91static int virtsnd_pcm_build_hw(struct virtio_pcm_substream *vss,
  92                                struct virtio_snd_pcm_info *info)
  93{
  94        struct virtio_device *vdev = vss->snd->vdev;
  95        unsigned int i;
  96        u64 values;
  97        size_t sample_max = 0;
  98        size_t sample_min = 0;
  99
 100        vss->features = le32_to_cpu(info->features);
 101
 102        /*
 103         * TODO: set SNDRV_PCM_INFO_{BATCH,BLOCK_TRANSFER} if device supports
 104         * only message-based transport.
 105         */
 106        vss->hw.info =
 107                SNDRV_PCM_INFO_MMAP |
 108                SNDRV_PCM_INFO_MMAP_VALID |
 109                SNDRV_PCM_INFO_BATCH |
 110                SNDRV_PCM_INFO_BLOCK_TRANSFER |
 111                SNDRV_PCM_INFO_INTERLEAVED |
 112                SNDRV_PCM_INFO_PAUSE;
 113
 114        if (!info->channels_min || info->channels_min > info->channels_max) {
 115                dev_err(&vdev->dev,
 116                        "SID %u: invalid channel range [%u %u]\n",
 117                        vss->sid, info->channels_min, info->channels_max);
 118                return -EINVAL;
 119        }
 120
 121        vss->hw.channels_min = info->channels_min;
 122        vss->hw.channels_max = info->channels_max;
 123
 124        values = le64_to_cpu(info->formats);
 125
 126        vss->hw.formats = 0;
 127
 128        for (i = 0; i < ARRAY_SIZE(g_v2a_format_map); ++i)
 129                if (values & (1ULL << i)) {
 130                        snd_pcm_format_t alsa_fmt = g_v2a_format_map[i];
 131                        int bytes = snd_pcm_format_physical_width(alsa_fmt) / 8;
 132
 133                        if (!sample_min || sample_min > bytes)
 134                                sample_min = bytes;
 135
 136                        if (sample_max < bytes)
 137                                sample_max = bytes;
 138
 139                        vss->hw.formats |= pcm_format_to_bits(alsa_fmt);
 140                }
 141
 142        if (!vss->hw.formats) {
 143                dev_err(&vdev->dev,
 144                        "SID %u: no supported PCM sample formats found\n",
 145                        vss->sid);
 146                return -EINVAL;
 147        }
 148
 149        values = le64_to_cpu(info->rates);
 150
 151        vss->hw.rates = 0;
 152
 153        for (i = 0; i < ARRAY_SIZE(g_v2a_rate_map); ++i)
 154                if (values & (1ULL << i)) {
 155                        if (!vss->hw.rate_min ||
 156                            vss->hw.rate_min > g_v2a_rate_map[i].rate)
 157                                vss->hw.rate_min = g_v2a_rate_map[i].rate;
 158
 159                        if (vss->hw.rate_max < g_v2a_rate_map[i].rate)
 160                                vss->hw.rate_max = g_v2a_rate_map[i].rate;
 161
 162                        vss->hw.rates |= g_v2a_rate_map[i].alsa_bit;
 163                }
 164
 165        if (!vss->hw.rates) {
 166                dev_err(&vdev->dev,
 167                        "SID %u: no supported PCM frame rates found\n",
 168                        vss->sid);
 169                return -EINVAL;
 170        }
 171
 172        vss->hw.periods_min = pcm_periods_min;
 173        vss->hw.periods_max = pcm_periods_max;
 174
 175        /*
 176         * We must ensure that there is enough space in the buffer to store
 177         * pcm_buffer_ms ms for the combination (Cmax, Smax, Rmax), where:
 178         *   Cmax = maximum supported number of channels,
 179         *   Smax = maximum supported sample size in bytes,
 180         *   Rmax = maximum supported frame rate.
 181         */
 182        vss->hw.buffer_bytes_max =
 183                PAGE_ALIGN(sample_max * vss->hw.channels_max * pcm_buffer_ms *
 184                           (vss->hw.rate_max / MSEC_PER_SEC));
 185
 186        /*
 187         * We must ensure that the minimum period size is enough to store
 188         * pcm_period_ms_min ms for the combination (Cmin, Smin, Rmin), where:
 189         *   Cmin = minimum supported number of channels,
 190         *   Smin = minimum supported sample size in bytes,
 191         *   Rmin = minimum supported frame rate.
 192         */
 193        vss->hw.period_bytes_min =
 194                sample_min * vss->hw.channels_min * pcm_period_ms_min *
 195                (vss->hw.rate_min / MSEC_PER_SEC);
 196
 197        /*
 198         * We must ensure that the maximum period size is enough to store
 199         * pcm_period_ms_max ms for the combination (Cmax, Smax, Rmax).
 200         */
 201        vss->hw.period_bytes_max =
 202                sample_max * vss->hw.channels_max * pcm_period_ms_max *
 203                (vss->hw.rate_max / MSEC_PER_SEC);
 204
 205        return 0;
 206}
 207
 208/**
 209 * virtsnd_pcm_find() - Find the PCM device for the specified node ID.
 210 * @snd: VirtIO sound device.
 211 * @nid: Function node ID.
 212 *
 213 * Context: Any context.
 214 * Return: a pointer to the PCM device or ERR_PTR(-ENOENT).
 215 */
 216struct virtio_pcm *virtsnd_pcm_find(struct virtio_snd *snd, u32 nid)
 217{
 218        struct virtio_pcm *vpcm;
 219
 220        list_for_each_entry(vpcm, &snd->pcm_list, list)
 221                if (vpcm->nid == nid)
 222                        return vpcm;
 223
 224        return ERR_PTR(-ENOENT);
 225}
 226
 227/**
 228 * virtsnd_pcm_find_or_create() - Find or create the PCM device for the
 229 *                                specified node ID.
 230 * @snd: VirtIO sound device.
 231 * @nid: Function node ID.
 232 *
 233 * Context: Any context that permits to sleep.
 234 * Return: a pointer to the PCM device or ERR_PTR(-errno).
 235 */
 236struct virtio_pcm *virtsnd_pcm_find_or_create(struct virtio_snd *snd, u32 nid)
 237{
 238        struct virtio_device *vdev = snd->vdev;
 239        struct virtio_pcm *vpcm;
 240
 241        vpcm = virtsnd_pcm_find(snd, nid);
 242        if (!IS_ERR(vpcm))
 243                return vpcm;
 244
 245        vpcm = devm_kzalloc(&vdev->dev, sizeof(*vpcm), GFP_KERNEL);
 246        if (!vpcm)
 247                return ERR_PTR(-ENOMEM);
 248
 249        vpcm->nid = nid;
 250        list_add_tail(&vpcm->list, &snd->pcm_list);
 251
 252        return vpcm;
 253}
 254
 255/**
 256 * virtsnd_pcm_validate() - Validate if the device can be started.
 257 * @vdev: VirtIO parent device.
 258 *
 259 * Context: Any context.
 260 * Return: 0 on success, -EINVAL on failure.
 261 */
 262int virtsnd_pcm_validate(struct virtio_device *vdev)
 263{
 264        if (pcm_periods_min < 2 || pcm_periods_min > pcm_periods_max) {
 265                dev_err(&vdev->dev,
 266                        "invalid range [%u %u] of the number of PCM periods\n",
 267                        pcm_periods_min, pcm_periods_max);
 268                return -EINVAL;
 269        }
 270
 271        if (!pcm_period_ms_min || pcm_period_ms_min > pcm_period_ms_max) {
 272                dev_err(&vdev->dev,
 273                        "invalid range [%u %u] of the size of the PCM period\n",
 274                        pcm_period_ms_min, pcm_period_ms_max);
 275                return -EINVAL;
 276        }
 277
 278        if (pcm_buffer_ms < pcm_periods_min * pcm_period_ms_min) {
 279                dev_err(&vdev->dev,
 280                        "pcm_buffer_ms(=%u) value cannot be < %u ms\n",
 281                        pcm_buffer_ms, pcm_periods_min * pcm_period_ms_min);
 282                return -EINVAL;
 283        }
 284
 285        if (pcm_period_ms_max > pcm_buffer_ms / 2) {
 286                dev_err(&vdev->dev,
 287                        "pcm_period_ms_max(=%u) value cannot be > %u ms\n",
 288                        pcm_period_ms_max, pcm_buffer_ms / 2);
 289                return -EINVAL;
 290        }
 291
 292        return 0;
 293}
 294
 295/**
 296 * virtsnd_pcm_period_elapsed() - Kernel work function to handle the elapsed
 297 *                                period state.
 298 * @work: Elapsed period work.
 299 *
 300 * The main purpose of this function is to call snd_pcm_period_elapsed() in
 301 * a process context, not in an interrupt context. This is necessary because PCM
 302 * devices operate in non-atomic mode.
 303 *
 304 * Context: Process context.
 305 */
 306static void virtsnd_pcm_period_elapsed(struct work_struct *work)
 307{
 308        struct virtio_pcm_substream *vss =
 309                container_of(work, struct virtio_pcm_substream, elapsed_period);
 310
 311        snd_pcm_period_elapsed(vss->substream);
 312}
 313
 314/**
 315 * virtsnd_pcm_parse_cfg() - Parse the stream configuration.
 316 * @snd: VirtIO sound device.
 317 *
 318 * This function is called during initial device initialization.
 319 *
 320 * Context: Any context that permits to sleep.
 321 * Return: 0 on success, -errno on failure.
 322 */
 323int virtsnd_pcm_parse_cfg(struct virtio_snd *snd)
 324{
 325        struct virtio_device *vdev = snd->vdev;
 326        struct virtio_snd_pcm_info *info;
 327        u32 i;
 328        int rc;
 329
 330        virtio_cread_le(vdev, struct virtio_snd_config, streams,
 331                        &snd->nsubstreams);
 332        if (!snd->nsubstreams)
 333                return 0;
 334
 335        snd->substreams = devm_kcalloc(&vdev->dev, snd->nsubstreams,
 336                                       sizeof(*snd->substreams), GFP_KERNEL);
 337        if (!snd->substreams)
 338                return -ENOMEM;
 339
 340        info = kcalloc(snd->nsubstreams, sizeof(*info), GFP_KERNEL);
 341        if (!info)
 342                return -ENOMEM;
 343
 344        rc = virtsnd_ctl_query_info(snd, VIRTIO_SND_R_PCM_INFO, 0,
 345                                    snd->nsubstreams, sizeof(*info), info);
 346        if (rc)
 347                goto on_exit;
 348
 349        for (i = 0; i < snd->nsubstreams; ++i) {
 350                struct virtio_pcm_substream *vss = &snd->substreams[i];
 351                struct virtio_pcm *vpcm;
 352
 353                vss->snd = snd;
 354                vss->sid = i;
 355                INIT_WORK(&vss->elapsed_period, virtsnd_pcm_period_elapsed);
 356                init_waitqueue_head(&vss->msg_empty);
 357                spin_lock_init(&vss->lock);
 358
 359                rc = virtsnd_pcm_build_hw(vss, &info[i]);
 360                if (rc)
 361                        goto on_exit;
 362
 363                vss->nid = le32_to_cpu(info[i].hdr.hda_fn_nid);
 364
 365                vpcm = virtsnd_pcm_find_or_create(snd, vss->nid);
 366                if (IS_ERR(vpcm)) {
 367                        rc = PTR_ERR(vpcm);
 368                        goto on_exit;
 369                }
 370
 371                switch (info[i].direction) {
 372                case VIRTIO_SND_D_OUTPUT:
 373                        vss->direction = SNDRV_PCM_STREAM_PLAYBACK;
 374                        break;
 375                case VIRTIO_SND_D_INPUT:
 376                        vss->direction = SNDRV_PCM_STREAM_CAPTURE;
 377                        break;
 378                default:
 379                        dev_err(&vdev->dev, "SID %u: unknown direction (%u)\n",
 380                                vss->sid, info[i].direction);
 381                        rc = -EINVAL;
 382                        goto on_exit;
 383                }
 384
 385                vpcm->streams[vss->direction].nsubstreams++;
 386        }
 387
 388on_exit:
 389        kfree(info);
 390
 391        return rc;
 392}
 393
 394/**
 395 * virtsnd_pcm_build_devs() - Build ALSA PCM devices.
 396 * @snd: VirtIO sound device.
 397 *
 398 * Context: Any context that permits to sleep.
 399 * Return: 0 on success, -errno on failure.
 400 */
 401int virtsnd_pcm_build_devs(struct virtio_snd *snd)
 402{
 403        struct virtio_device *vdev = snd->vdev;
 404        struct virtio_pcm *vpcm;
 405        u32 i;
 406        int rc;
 407
 408        list_for_each_entry(vpcm, &snd->pcm_list, list) {
 409                unsigned int npbs =
 410                        vpcm->streams[SNDRV_PCM_STREAM_PLAYBACK].nsubstreams;
 411                unsigned int ncps =
 412                        vpcm->streams[SNDRV_PCM_STREAM_CAPTURE].nsubstreams;
 413
 414                if (!npbs && !ncps)
 415                        continue;
 416
 417                rc = snd_pcm_new(snd->card, VIRTIO_SND_CARD_DRIVER, vpcm->nid,
 418                                 npbs, ncps, &vpcm->pcm);
 419                if (rc) {
 420                        dev_err(&vdev->dev, "snd_pcm_new[%u] failed: %d\n",
 421                                vpcm->nid, rc);
 422                        return rc;
 423                }
 424
 425                vpcm->pcm->info_flags = 0;
 426                vpcm->pcm->dev_class = SNDRV_PCM_CLASS_GENERIC;
 427                vpcm->pcm->dev_subclass = SNDRV_PCM_SUBCLASS_GENERIC_MIX;
 428                snprintf(vpcm->pcm->name, sizeof(vpcm->pcm->name),
 429                         VIRTIO_SND_PCM_NAME " %u", vpcm->pcm->device);
 430                vpcm->pcm->private_data = vpcm;
 431                vpcm->pcm->nonatomic = true;
 432
 433                for (i = 0; i < ARRAY_SIZE(vpcm->streams); ++i) {
 434                        struct virtio_pcm_stream *stream = &vpcm->streams[i];
 435
 436                        if (!stream->nsubstreams)
 437                                continue;
 438
 439                        stream->substreams =
 440                                devm_kcalloc(&vdev->dev, stream->nsubstreams,
 441                                             sizeof(*stream->substreams),
 442                                             GFP_KERNEL);
 443                        if (!stream->substreams)
 444                                return -ENOMEM;
 445
 446                        stream->nsubstreams = 0;
 447                }
 448        }
 449
 450        for (i = 0; i < snd->nsubstreams; ++i) {
 451                struct virtio_pcm_stream *vs;
 452                struct virtio_pcm_substream *vss = &snd->substreams[i];
 453
 454                vpcm = virtsnd_pcm_find(snd, vss->nid);
 455                if (IS_ERR(vpcm))
 456                        return PTR_ERR(vpcm);
 457
 458                vs = &vpcm->streams[vss->direction];
 459                vs->substreams[vs->nsubstreams++] = vss;
 460        }
 461
 462        list_for_each_entry(vpcm, &snd->pcm_list, list) {
 463                for (i = 0; i < ARRAY_SIZE(vpcm->streams); ++i) {
 464                        struct virtio_pcm_stream *vs = &vpcm->streams[i];
 465                        struct snd_pcm_str *ks = &vpcm->pcm->streams[i];
 466                        struct snd_pcm_substream *kss;
 467
 468                        if (!vs->nsubstreams)
 469                                continue;
 470
 471                        for (kss = ks->substream; kss; kss = kss->next)
 472                                vs->substreams[kss->number]->substream = kss;
 473
 474                        snd_pcm_set_ops(vpcm->pcm, i, &virtsnd_pcm_ops);
 475                }
 476
 477                snd_pcm_set_managed_buffer_all(vpcm->pcm,
 478                                               SNDRV_DMA_TYPE_VMALLOC, NULL,
 479                                               0, 0);
 480        }
 481
 482        return 0;
 483}
 484
 485/**
 486 * virtsnd_pcm_event() - Handle the PCM device event notification.
 487 * @snd: VirtIO sound device.
 488 * @event: VirtIO sound event.
 489 *
 490 * Context: Interrupt context.
 491 */
 492void virtsnd_pcm_event(struct virtio_snd *snd, struct virtio_snd_event *event)
 493{
 494        struct virtio_pcm_substream *vss;
 495        u32 sid = le32_to_cpu(event->data);
 496
 497        if (sid >= snd->nsubstreams)
 498                return;
 499
 500        vss = &snd->substreams[sid];
 501
 502        switch (le32_to_cpu(event->hdr.code)) {
 503        case VIRTIO_SND_EVT_PCM_PERIOD_ELAPSED:
 504                /* TODO: deal with shmem elapsed period */
 505                break;
 506        case VIRTIO_SND_EVT_PCM_XRUN:
 507                spin_lock(&vss->lock);
 508                if (vss->xfer_enabled)
 509                        vss->xfer_xrun = true;
 510                spin_unlock(&vss->lock);
 511                break;
 512        }
 513}
 514