sound/virtio/virtio_pcm.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 /*
0003  * virtio-snd: Virtio sound device
0004  * Copyright (C) 2021 OpenSynergy GmbH
0005  */
0006 #include <linux/moduleparam.h>
0007 #include <linux/virtio_config.h>
0008
0009 #include "virtio_card.h"
0010
0011 static u32 pcm_buffer_ms = 160;
0012 module_param(pcm_buffer_ms, uint, 0644);
0013 MODULE_PARM_DESC(pcm_buffer_ms, "PCM substream buffer time in milliseconds");
0014
0015 static u32 pcm_periods_min = 2;
0016 module_param(pcm_periods_min, uint, 0644);
0017 MODULE_PARM_DESC(pcm_periods_min, "Minimum number of PCM periods");
0018
0019 static u32 pcm_periods_max = 16;
0020 module_param(pcm_periods_max, uint, 0644);
0021 MODULE_PARM_DESC(pcm_periods_max, "Maximum number of PCM periods");
0022
0023 static u32 pcm_period_ms_min = 10;
0024 module_param(pcm_period_ms_min, uint, 0644);
0025 MODULE_PARM_DESC(pcm_period_ms_min, "Minimum PCM period time in milliseconds");
0026
0027 static u32 pcm_period_ms_max = 80;
0028 module_param(pcm_period_ms_max, uint, 0644);
0029 MODULE_PARM_DESC(pcm_period_ms_max, "Maximum PCM period time in milliseconds");
0030
0031 /* Map for converting VirtIO format to ALSA format. */
0032 static const snd_pcm_format_t g_v2a_format_map[] = {
0033     [VIRTIO_SND_PCM_FMT_IMA_ADPCM] = SNDRV_PCM_FORMAT_IMA_ADPCM,
0034     [VIRTIO_SND_PCM_FMT_MU_LAW] = SNDRV_PCM_FORMAT_MU_LAW,
0035     [VIRTIO_SND_PCM_FMT_A_LAW] = SNDRV_PCM_FORMAT_A_LAW,
0036     [VIRTIO_SND_PCM_FMT_S8] = SNDRV_PCM_FORMAT_S8,
0037     [VIRTIO_SND_PCM_FMT_U8] = SNDRV_PCM_FORMAT_U8,
0038     [VIRTIO_SND_PCM_FMT_S16] = SNDRV_PCM_FORMAT_S16_LE,
0039     [VIRTIO_SND_PCM_FMT_U16] = SNDRV_PCM_FORMAT_U16_LE,
0040     [VIRTIO_SND_PCM_FMT_S18_3] = SNDRV_PCM_FORMAT_S18_3LE,
0041     [VIRTIO_SND_PCM_FMT_U18_3] = SNDRV_PCM_FORMAT_U18_3LE,
0042     [VIRTIO_SND_PCM_FMT_S20_3] = SNDRV_PCM_FORMAT_S20_3LE,
0043     [VIRTIO_SND_PCM_FMT_U20_3] = SNDRV_PCM_FORMAT_U20_3LE,
0044     [VIRTIO_SND_PCM_FMT_S24_3] = SNDRV_PCM_FORMAT_S24_3LE,
0045     [VIRTIO_SND_PCM_FMT_U24_3] = SNDRV_PCM_FORMAT_U24_3LE,
0046     [VIRTIO_SND_PCM_FMT_S20] = SNDRV_PCM_FORMAT_S20_LE,
0047     [VIRTIO_SND_PCM_FMT_U20] = SNDRV_PCM_FORMAT_U20_LE,
0048     [VIRTIO_SND_PCM_FMT_S24] = SNDRV_PCM_FORMAT_S24_LE,
0049     [VIRTIO_SND_PCM_FMT_U24] = SNDRV_PCM_FORMAT_U24_LE,
0050     [VIRTIO_SND_PCM_FMT_S32] = SNDRV_PCM_FORMAT_S32_LE,
0051     [VIRTIO_SND_PCM_FMT_U32] = SNDRV_PCM_FORMAT_U32_LE,
0052     [VIRTIO_SND_PCM_FMT_FLOAT] = SNDRV_PCM_FORMAT_FLOAT_LE,
0053     [VIRTIO_SND_PCM_FMT_FLOAT64] = SNDRV_PCM_FORMAT_FLOAT64_LE,
0054     [VIRTIO_SND_PCM_FMT_DSD_U8] = SNDRV_PCM_FORMAT_DSD_U8,
0055     [VIRTIO_SND_PCM_FMT_DSD_U16] = SNDRV_PCM_FORMAT_DSD_U16_LE,
0056     [VIRTIO_SND_PCM_FMT_DSD_U32] = SNDRV_PCM_FORMAT_DSD_U32_LE,
0057     [VIRTIO_SND_PCM_FMT_IEC958_SUBFRAME] =
0058         SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE
0059 };
0060
0061 /* Map for converting VirtIO frame rate to ALSA frame rate. */
0062 struct virtsnd_v2a_rate {
0063     unsigned int alsa_bit;
0064     unsigned int rate;
0065 };
0066
0067 static const struct virtsnd_v2a_rate g_v2a_rate_map[] = {
0068     [VIRTIO_SND_PCM_RATE_5512] = { SNDRV_PCM_RATE_5512, 5512 },
0069     [VIRTIO_SND_PCM_RATE_8000] = { SNDRV_PCM_RATE_8000, 8000 },
0070     [VIRTIO_SND_PCM_RATE_11025] = { SNDRV_PCM_RATE_11025, 11025 },
0071     [VIRTIO_SND_PCM_RATE_16000] = { SNDRV_PCM_RATE_16000, 16000 },
0072     [VIRTIO_SND_PCM_RATE_22050] = { SNDRV_PCM_RATE_22050, 22050 },
0073     [VIRTIO_SND_PCM_RATE_32000] = { SNDRV_PCM_RATE_32000, 32000 },
0074     [VIRTIO_SND_PCM_RATE_44100] = { SNDRV_PCM_RATE_44100, 44100 },
0075     [VIRTIO_SND_PCM_RATE_48000] = { SNDRV_PCM_RATE_48000, 48000 },
0076     [VIRTIO_SND_PCM_RATE_64000] = { SNDRV_PCM_RATE_64000, 64000 },
0077     [VIRTIO_SND_PCM_RATE_88200] = { SNDRV_PCM_RATE_88200, 88200 },
0078     [VIRTIO_SND_PCM_RATE_96000] = { SNDRV_PCM_RATE_96000, 96000 },
0079     [VIRTIO_SND_PCM_RATE_176400] = { SNDRV_PCM_RATE_176400, 176400 },
0080     [VIRTIO_SND_PCM_RATE_192000] = { SNDRV_PCM_RATE_192000, 192000 }
0081 };
0082
0083 /**
0084  * virtsnd_pcm_build_hw() - Parse substream config and build HW descriptor.
0085  * @vss: VirtIO substream.
0086  * @info: VirtIO substream information entry.
0087  *
0088  * Context: Any context.
0089  * Return: 0 on success, -EINVAL if configuration is invalid.
0090  */
0091 static int virtsnd_pcm_build_hw(struct virtio_pcm_substream *vss,
0092                 struct virtio_snd_pcm_info *info)
0093 {
0094     struct virtio_device *vdev = vss->snd->vdev;
0095     unsigned int i;
0096     u64 values;
0097     size_t sample_max = 0;
0098     size_t sample_min = 0;
0099
0100     vss->features = le32_to_cpu(info->features);
0101
0102     /*
0103      * TODO: set SNDRV_PCM_INFO_{BATCH,BLOCK_TRANSFER} if device supports
0104      * only message-based transport.
0105      */
0106     vss->hw.info =
0107         SNDRV_PCM_INFO_MMAP |
0108         SNDRV_PCM_INFO_MMAP_VALID |
0109         SNDRV_PCM_INFO_BATCH |
0110         SNDRV_PCM_INFO_BLOCK_TRANSFER |
0111         SNDRV_PCM_INFO_INTERLEAVED |
0112         SNDRV_PCM_INFO_PAUSE;
0113
0114     if (!info->channels_min || info->channels_min > info->channels_max) {
0115         dev_err(&vdev->dev,
0116             "SID %u: invalid channel range [%u %u]\n",
0117             vss->sid, info->channels_min, info->channels_max);
0118         return -EINVAL;
0119     }
0120
0121     vss->hw.channels_min = info->channels_min;
0122     vss->hw.channels_max = info->channels_max;
0123
0124     values = le64_to_cpu(info->formats);
0125
0126     vss->hw.formats = 0;
0127
0128     for (i = 0; i < ARRAY_SIZE(g_v2a_format_map); ++i)
0129         if (values & (1ULL << i)) {
0130             snd_pcm_format_t alsa_fmt = g_v2a_format_map[i];
0131             int bytes = snd_pcm_format_physical_width(alsa_fmt) / 8;
0132
0133             if (!sample_min || sample_min > bytes)
0134                 sample_min = bytes;
0135
0136             if (sample_max < bytes)
0137                 sample_max = bytes;
0138
0139             vss->hw.formats |= pcm_format_to_bits(alsa_fmt);
0140         }
0141
0142     if (!vss->hw.formats) {
0143         dev_err(&vdev->dev,
0144             "SID %u: no supported PCM sample formats found\n",
0145             vss->sid);
0146         return -EINVAL;
0147     }
0148
0149     values = le64_to_cpu(info->rates);
0150
0151     vss->hw.rates = 0;
0152
0153     for (i = 0; i < ARRAY_SIZE(g_v2a_rate_map); ++i)
0154         if (values & (1ULL << i)) {
0155             if (!vss->hw.rate_min ||
0156                 vss->hw.rate_min > g_v2a_rate_map[i].rate)
0157                 vss->hw.rate_min = g_v2a_rate_map[i].rate;
0158
0159             if (vss->hw.rate_max < g_v2a_rate_map[i].rate)
0160                 vss->hw.rate_max = g_v2a_rate_map[i].rate;
0161
0162             vss->hw.rates |= g_v2a_rate_map[i].alsa_bit;
0163         }
0164
0165     if (!vss->hw.rates) {
0166         dev_err(&vdev->dev,
0167             "SID %u: no supported PCM frame rates found\n",
0168             vss->sid);
0169         return -EINVAL;
0170     }
0171
0172     vss->hw.periods_min = pcm_periods_min;
0173     vss->hw.periods_max = pcm_periods_max;
0174
0175     /*
0176      * We must ensure that there is enough space in the buffer to store
0177      * pcm_buffer_ms ms for the combination (Cmax, Smax, Rmax), where:
0178      *   Cmax = maximum supported number of channels,
0179      *   Smax = maximum supported sample size in bytes,
0180      *   Rmax = maximum supported frame rate.
0181      */
0182     vss->hw.buffer_bytes_max =
0183         PAGE_ALIGN(sample_max * vss->hw.channels_max * pcm_buffer_ms *
0184                (vss->hw.rate_max / MSEC_PER_SEC));
0185
0186     /*
0187      * We must ensure that the minimum period size is enough to store
0188      * pcm_period_ms_min ms for the combination (Cmin, Smin, Rmin), where:
0189      *   Cmin = minimum supported number of channels,
0190      *   Smin = minimum supported sample size in bytes,
0191      *   Rmin = minimum supported frame rate.
0192      */
0193     vss->hw.period_bytes_min =
0194         sample_min * vss->hw.channels_min * pcm_period_ms_min *
0195         (vss->hw.rate_min / MSEC_PER_SEC);
0196
0197     /*
0198      * We must ensure that the maximum period size is enough to store
0199      * pcm_period_ms_max ms for the combination (Cmax, Smax, Rmax).
0200      */
0201     vss->hw.period_bytes_max =
0202         sample_max * vss->hw.channels_max * pcm_period_ms_max *
0203         (vss->hw.rate_max / MSEC_PER_SEC);
0204
0205     return 0;
0206 }
0207
0208 /**
0209  * virtsnd_pcm_find() - Find the PCM device for the specified node ID.
0210  * @snd: VirtIO sound device.
0211  * @nid: Function node ID.
0212  *
0213  * Context: Any context.
0214  * Return: a pointer to the PCM device or ERR_PTR(-ENOENT).
0215  */
0216 struct virtio_pcm *virtsnd_pcm_find(struct virtio_snd *snd, u32 nid)
0217 {
0218     struct virtio_pcm *vpcm;
0219
0220     list_for_each_entry(vpcm, &snd->pcm_list, list)
0221         if (vpcm->nid == nid)
0222             return vpcm;
0223
0224     return ERR_PTR(-ENOENT);
0225 }
0226
0227 /**
0228  * virtsnd_pcm_find_or_create() - Find or create the PCM device for the
0229  *                                specified node ID.
0230  * @snd: VirtIO sound device.
0231  * @nid: Function node ID.
0232  *
0233  * Context: Any context that permits to sleep.
0234  * Return: a pointer to the PCM device or ERR_PTR(-errno).
0235  */
0236 struct virtio_pcm *virtsnd_pcm_find_or_create(struct virtio_snd *snd, u32 nid)
0237 {
0238     struct virtio_device *vdev = snd->vdev;
0239     struct virtio_pcm *vpcm;
0240
0241     vpcm = virtsnd_pcm_find(snd, nid);
0242     if (!IS_ERR(vpcm))
0243         return vpcm;
0244
0245     vpcm = devm_kzalloc(&vdev->dev, sizeof(*vpcm), GFP_KERNEL);
0246     if (!vpcm)
0247         return ERR_PTR(-ENOMEM);
0248
0249     vpcm->nid = nid;
0250     list_add_tail(&vpcm->list, &snd->pcm_list);
0251
0252     return vpcm;
0253 }
0254
0255 /**
0256  * virtsnd_pcm_validate() - Validate if the device can be started.
0257  * @vdev: VirtIO parent device.
0258  *
0259  * Context: Any context.
0260  * Return: 0 on success, -EINVAL on failure.
0261  */
0262 int virtsnd_pcm_validate(struct virtio_device *vdev)
0263 {
0264     if (pcm_periods_min < 2 || pcm_periods_min > pcm_periods_max) {
0265         dev_err(&vdev->dev,
0266             "invalid range [%u %u] of the number of PCM periods\n",
0267             pcm_periods_min, pcm_periods_max);
0268         return -EINVAL;
0269     }
0270
0271     if (!pcm_period_ms_min || pcm_period_ms_min > pcm_period_ms_max) {
0272         dev_err(&vdev->dev,
0273             "invalid range [%u %u] of the size of the PCM period\n",
0274             pcm_period_ms_min, pcm_period_ms_max);
0275         return -EINVAL;
0276     }
0277
0278     if (pcm_buffer_ms < pcm_periods_min * pcm_period_ms_min) {
0279         dev_err(&vdev->dev,
0280             "pcm_buffer_ms(=%u) value cannot be < %u ms\n",
0281             pcm_buffer_ms, pcm_periods_min * pcm_period_ms_min);
0282         return -EINVAL;
0283     }
0284
0285     if (pcm_period_ms_max > pcm_buffer_ms / 2) {
0286         dev_err(&vdev->dev,
0287             "pcm_period_ms_max(=%u) value cannot be > %u ms\n",
0288             pcm_period_ms_max, pcm_buffer_ms / 2);
0289         return -EINVAL;
0290     }
0291
0292     return 0;
0293 }
0294
0295 /**
0296  * virtsnd_pcm_period_elapsed() - Kernel work function to handle the elapsed
0297  *                                period state.
0298  * @work: Elapsed period work.
0299  *
0300  * The main purpose of this function is to call snd_pcm_period_elapsed() in
0301  * a process context, not in an interrupt context. This is necessary because PCM
0302  * devices operate in non-atomic mode.
0303  *
0304  * Context: Process context.
0305  */
0306 static void virtsnd_pcm_period_elapsed(struct work_struct *work)
0307 {
0308     struct virtio_pcm_substream *vss =
0309         container_of(work, struct virtio_pcm_substream, elapsed_period);
0310
0311     snd_pcm_period_elapsed(vss->substream);
0312 }
0313
0314 /**
0315  * virtsnd_pcm_parse_cfg() - Parse the stream configuration.
0316  * @snd: VirtIO sound device.
0317  *
0318  * This function is called during initial device initialization.
0319  *
0320  * Context: Any context that permits to sleep.
0321  * Return: 0 on success, -errno on failure.
0322  */
0323 int virtsnd_pcm_parse_cfg(struct virtio_snd *snd)
0324 {
0325     struct virtio_device *vdev = snd->vdev;
0326     struct virtio_snd_pcm_info *info;
0327     u32 i;
0328     int rc;
0329
0330     virtio_cread_le(vdev, struct virtio_snd_config, streams,
0331             &snd->nsubstreams);
0332     if (!snd->nsubstreams)
0333         return 0;
0334
0335     snd->substreams = devm_kcalloc(&vdev->dev, snd->nsubstreams,
0336                        sizeof(*snd->substreams), GFP_KERNEL);
0337     if (!snd->substreams)
0338         return -ENOMEM;
0339
0340     info = kcalloc(snd->nsubstreams, sizeof(*info), GFP_KERNEL);
0341     if (!info)
0342         return -ENOMEM;
0343
0344     rc = virtsnd_ctl_query_info(snd, VIRTIO_SND_R_PCM_INFO, 0,
0345                     snd->nsubstreams, sizeof(*info), info);
0346     if (rc)
0347         goto on_exit;
0348
0349     for (i = 0; i < snd->nsubstreams; ++i) {
0350         struct virtio_pcm_substream *vss = &snd->substreams[i];
0351         struct virtio_pcm *vpcm;
0352
0353         vss->snd = snd;
0354         vss->sid = i;
0355         INIT_WORK(&vss->elapsed_period, virtsnd_pcm_period_elapsed);
0356         init_waitqueue_head(&vss->msg_empty);
0357         spin_lock_init(&vss->lock);
0358
0359         rc = virtsnd_pcm_build_hw(vss, &info[i]);
0360         if (rc)
0361             goto on_exit;
0362
0363         vss->nid = le32_to_cpu(info[i].hdr.hda_fn_nid);
0364
0365         vpcm = virtsnd_pcm_find_or_create(snd, vss->nid);
0366         if (IS_ERR(vpcm)) {
0367             rc = PTR_ERR(vpcm);
0368             goto on_exit;
0369         }
0370
0371         switch (info[i].direction) {
0372         case VIRTIO_SND_D_OUTPUT:
0373             vss->direction = SNDRV_PCM_STREAM_PLAYBACK;
0374             break;
0375         case VIRTIO_SND_D_INPUT:
0376             vss->direction = SNDRV_PCM_STREAM_CAPTURE;
0377             break;
0378         default:
0379             dev_err(&vdev->dev, "SID %u: unknown direction (%u)\n",
0380                 vss->sid, info[i].direction);
0381             rc = -EINVAL;
0382             goto on_exit;
0383         }
0384
0385         vpcm->streams[vss->direction].nsubstreams++;
0386     }
0387
0388 on_exit:
0389     kfree(info);
0390
0391     return rc;
0392 }
0393
0394 /**
0395  * virtsnd_pcm_build_devs() - Build ALSA PCM devices.
0396  * @snd: VirtIO sound device.
0397  *
0398  * Context: Any context that permits to sleep.
0399  * Return: 0 on success, -errno on failure.
0400  */
0401 int virtsnd_pcm_build_devs(struct virtio_snd *snd)
0402 {
0403     struct virtio_device *vdev = snd->vdev;
0404     struct virtio_pcm *vpcm;
0405     u32 i;
0406     int rc;
0407
0408     list_for_each_entry(vpcm, &snd->pcm_list, list) {
0409         unsigned int npbs =
0410             vpcm->streams[SNDRV_PCM_STREAM_PLAYBACK].nsubstreams;
0411         unsigned int ncps =
0412             vpcm->streams[SNDRV_PCM_STREAM_CAPTURE].nsubstreams;
0413
0414         if (!npbs && !ncps)
0415             continue;
0416
0417         rc = snd_pcm_new(snd->card, VIRTIO_SND_CARD_DRIVER, vpcm->nid,
0418                  npbs, ncps, &vpcm->pcm);
0419         if (rc) {
0420             dev_err(&vdev->dev, "snd_pcm_new[%u] failed: %d\n",
0421                 vpcm->nid, rc);
0422             return rc;
0423         }
0424
0425         vpcm->pcm->info_flags = 0;
0426         vpcm->pcm->dev_class = SNDRV_PCM_CLASS_GENERIC;
0427         vpcm->pcm->dev_subclass = SNDRV_PCM_SUBCLASS_GENERIC_MIX;
0428         snprintf(vpcm->pcm->name, sizeof(vpcm->pcm->name),
0429              VIRTIO_SND_PCM_NAME " %u", vpcm->pcm->device);
0430         vpcm->pcm->private_data = vpcm;
0431         vpcm->pcm->nonatomic = true;
0432
0433         for (i = 0; i < ARRAY_SIZE(vpcm->streams); ++i) {
0434             struct virtio_pcm_stream *stream = &vpcm->streams[i];
0435
0436             if (!stream->nsubstreams)
0437                 continue;
0438
0439             stream->substreams =
0440                 devm_kcalloc(&vdev->dev, stream->nsubstreams,
0441                          sizeof(*stream->substreams),
0442                          GFP_KERNEL);
0443             if (!stream->substreams)
0444                 return -ENOMEM;
0445
0446             stream->nsubstreams = 0;
0447         }
0448     }
0449
0450     for (i = 0; i < snd->nsubstreams; ++i) {
0451         struct virtio_pcm_stream *vs;
0452         struct virtio_pcm_substream *vss = &snd->substreams[i];
0453
0454         vpcm = virtsnd_pcm_find(snd, vss->nid);
0455         if (IS_ERR(vpcm))
0456             return PTR_ERR(vpcm);
0457
0458         vs = &vpcm->streams[vss->direction];
0459         vs->substreams[vs->nsubstreams++] = vss;
0460     }
0461
0462     list_for_each_entry(vpcm, &snd->pcm_list, list) {
0463         for (i = 0; i < ARRAY_SIZE(vpcm->streams); ++i) {
0464             struct virtio_pcm_stream *vs = &vpcm->streams[i];
0465             struct snd_pcm_str *ks = &vpcm->pcm->streams[i];
0466             struct snd_pcm_substream *kss;
0467
0468             if (!vs->nsubstreams)
0469                 continue;
0470
0471             for (kss = ks->substream; kss; kss = kss->next)
0472                 vs->substreams[kss->number]->substream = kss;
0473
0474             snd_pcm_set_ops(vpcm->pcm, i, &virtsnd_pcm_ops);
0475         }
0476
0477         snd_pcm_set_managed_buffer_all(vpcm->pcm,
0478                            SNDRV_DMA_TYPE_VMALLOC, NULL,
0479                            0, 0);
0480     }
0481
0482     return 0;
0483 }
0484
0485 /**
0486  * virtsnd_pcm_event() - Handle the PCM device event notification.
0487  * @snd: VirtIO sound device.
0488  * @event: VirtIO sound event.
0489  *
0490  * Context: Interrupt context.
0491  */
0492 void virtsnd_pcm_event(struct virtio_snd *snd, struct virtio_snd_event *event)
0493 {
0494     struct virtio_pcm_substream *vss;
0495     u32 sid = le32_to_cpu(event->data);
0496
0497     if (sid >= snd->nsubstreams)
0498         return;
0499
0500     vss = &snd->substreams[sid];
0501
0502     switch (le32_to_cpu(event->hdr.code)) {
0503     case VIRTIO_SND_EVT_PCM_PERIOD_ELAPSED:
0504         /* TODO: deal with shmem elapsed period */
0505         break;
0506     case VIRTIO_SND_EVT_PCM_XRUN:
0507         spin_lock(&vss->lock);
0508         if (vss->xfer_enabled)
0509             vss->xfer_xrun = true;
0510         spin_unlock(&vss->lock);
0511         break;
0512     }
0513 }