Like the HDA specification, the virtio sound device specification links PCM substreams, jacks and PCM channel maps into functional groups. For each discovered group, a PCM device is created, the number of which coincides with the group number.
Introduce the module parameters for setting the hardware buffer parameters: pcm_buffer_ms [=160] pcm_periods_min [=2] pcm_periods_max [=16] pcm_period_ms_min [=10] pcm_period_ms_max [=80]
Signed-off-by: Anton Yakovlev anton.yakovlev@opensynergy.com --- sound/virtio/Makefile | 3 +- sound/virtio/virtio_card.c | 14 ++ sound/virtio/virtio_card.h | 10 + sound/virtio/virtio_pcm.c | 464 +++++++++++++++++++++++++++++++++++++ sound/virtio/virtio_pcm.h | 71 ++++++ 5 files changed, 561 insertions(+), 1 deletion(-) create mode 100644 sound/virtio/virtio_pcm.c create mode 100644 sound/virtio/virtio_pcm.h
diff --git a/sound/virtio/Makefile b/sound/virtio/Makefile index dc551e637441..69162a545a41 100644 --- a/sound/virtio/Makefile +++ b/sound/virtio/Makefile @@ -4,5 +4,6 @@ obj-$(CONFIG_SND_VIRTIO) += virtio_snd.o
virtio_snd-objs := \ virtio_card.o \ - virtio_ctl_msg.o + virtio_ctl_msg.o \ + virtio_pcm.o
diff --git a/sound/virtio/virtio_card.c b/sound/virtio/virtio_card.c index c62b3a2da148..235afc25fce7 100644 --- a/sound/virtio/virtio_card.c +++ b/sound/virtio/virtio_card.c @@ -200,6 +200,16 @@ static int virtsnd_build_devs(struct virtio_snd *snd) VIRTIO_SND_CARD_NAME " at %s/%s", dev_name(dev->parent), dev_name(dev));
+ rc = virtsnd_pcm_parse_cfg(snd); + if (rc) + return rc; + + if (snd->nsubstreams) { + rc = virtsnd_pcm_build_devs(snd); + if (rc) + return rc; + } + return snd_card_register(snd->card); }
@@ -228,6 +238,9 @@ static int virtsnd_validate(struct virtio_device *vdev) return -EINVAL; }
+ if (virtsnd_pcm_validate(vdev)) + return -EINVAL; + return 0; }
@@ -251,6 +264,7 @@ static int virtsnd_probe(struct virtio_device *vdev) snd->vdev = vdev; INIT_WORK(&snd->reset_work, virtsnd_reset_fn); INIT_LIST_HEAD(&snd->ctl_msgs); + INIT_LIST_HEAD(&snd->pcm_list);
vdev->priv = snd;
diff --git a/sound/virtio/virtio_card.h b/sound/virtio/virtio_card.h index c51a71a79388..687d3ed6d1c3 100644 --- a/sound/virtio/virtio_card.h +++ b/sound/virtio/virtio_card.h @@ -12,9 +12,13 @@ #include <uapi/linux/virtio_snd.h>
#include "virtio_ctl_msg.h" +#include "virtio_pcm.h"
#define VIRTIO_SND_CARD_DRIVER "virtio-snd" #define VIRTIO_SND_CARD_NAME "VirtIO SoundCard" +#define VIRTIO_SND_PCM_NAME "VirtIO PCM" + +struct virtio_pcm_substream;
/** * struct virtio_snd_queue - Virtqueue wrapper structure. @@ -34,6 +38,9 @@ struct virtio_snd_queue { * @card: ALSA sound card. * @ctl_msgs: Pending control request list. * @event_msgs: Device events. + * @pcm_list: VirtIO PCM device list. + * @substreams: VirtIO PCM substreams. + * @nsubstreams: Number of PCM substreams. */ struct virtio_snd { struct virtio_device *vdev; @@ -42,6 +49,9 @@ struct virtio_snd { struct snd_card *card; struct list_head ctl_msgs; struct virtio_snd_event *event_msgs; + struct list_head pcm_list; + struct virtio_pcm_substream *substreams; + unsigned int nsubstreams; };
/* Message completion timeout in milliseconds (module parameter). */ diff --git a/sound/virtio/virtio_pcm.c b/sound/virtio/virtio_pcm.c new file mode 100644 index 000000000000..92f2f4cb338f --- /dev/null +++ b/sound/virtio/virtio_pcm.c @@ -0,0 +1,464 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * virtio-snd: Virtio sound device + * Copyright (C) 2021 OpenSynergy GmbH + */ +#include <linux/moduleparam.h> +#include <linux/virtio_config.h> + +#include "virtio_card.h" + +static unsigned int pcm_buffer_ms = 160; +module_param(pcm_buffer_ms, uint, 0644); +MODULE_PARM_DESC(pcm_buffer_ms, "PCM substream buffer time in milliseconds"); + +static unsigned int pcm_periods_min = 2; +module_param(pcm_periods_min, uint, 0644); +MODULE_PARM_DESC(pcm_periods_min, "Minimum number of PCM periods"); + +static unsigned int pcm_periods_max = 16; +module_param(pcm_periods_max, uint, 0644); +MODULE_PARM_DESC(pcm_periods_max, "Maximum number of PCM periods"); + +static unsigned int pcm_period_ms_min = 10; +module_param(pcm_period_ms_min, uint, 0644); +MODULE_PARM_DESC(pcm_period_ms_min, "Minimum PCM period time in milliseconds"); + +static unsigned int pcm_period_ms_max = 80; +module_param(pcm_period_ms_max, uint, 0644); +MODULE_PARM_DESC(pcm_period_ms_max, "Maximum PCM period time in milliseconds"); + +/* Map for converting VirtIO format to ALSA format. */ +static const unsigned int g_v2a_format_map[] = { + [VIRTIO_SND_PCM_FMT_IMA_ADPCM] = SNDRV_PCM_FORMAT_IMA_ADPCM, + [VIRTIO_SND_PCM_FMT_MU_LAW] = SNDRV_PCM_FORMAT_MU_LAW, + [VIRTIO_SND_PCM_FMT_A_LAW] = SNDRV_PCM_FORMAT_A_LAW, + [VIRTIO_SND_PCM_FMT_S8] = SNDRV_PCM_FORMAT_S8, + [VIRTIO_SND_PCM_FMT_U8] = SNDRV_PCM_FORMAT_U8, + [VIRTIO_SND_PCM_FMT_S16] = SNDRV_PCM_FORMAT_S16_LE, + [VIRTIO_SND_PCM_FMT_U16] = SNDRV_PCM_FORMAT_U16_LE, + [VIRTIO_SND_PCM_FMT_S18_3] = SNDRV_PCM_FORMAT_S18_3LE, + [VIRTIO_SND_PCM_FMT_U18_3] = SNDRV_PCM_FORMAT_U18_3LE, + [VIRTIO_SND_PCM_FMT_S20_3] = SNDRV_PCM_FORMAT_S20_3LE, + [VIRTIO_SND_PCM_FMT_U20_3] = SNDRV_PCM_FORMAT_U20_3LE, + [VIRTIO_SND_PCM_FMT_S24_3] = SNDRV_PCM_FORMAT_S24_3LE, + [VIRTIO_SND_PCM_FMT_U24_3] = SNDRV_PCM_FORMAT_U24_3LE, + [VIRTIO_SND_PCM_FMT_S20] = SNDRV_PCM_FORMAT_S20_LE, + [VIRTIO_SND_PCM_FMT_U20] = SNDRV_PCM_FORMAT_U20_LE, + [VIRTIO_SND_PCM_FMT_S24] = SNDRV_PCM_FORMAT_S24_LE, + [VIRTIO_SND_PCM_FMT_U24] = SNDRV_PCM_FORMAT_U24_LE, + [VIRTIO_SND_PCM_FMT_S32] = SNDRV_PCM_FORMAT_S32_LE, + [VIRTIO_SND_PCM_FMT_U32] = SNDRV_PCM_FORMAT_U32_LE, + [VIRTIO_SND_PCM_FMT_FLOAT] = SNDRV_PCM_FORMAT_FLOAT_LE, + [VIRTIO_SND_PCM_FMT_FLOAT64] = SNDRV_PCM_FORMAT_FLOAT64_LE, + [VIRTIO_SND_PCM_FMT_DSD_U8] = SNDRV_PCM_FORMAT_DSD_U8, + [VIRTIO_SND_PCM_FMT_DSD_U16] = SNDRV_PCM_FORMAT_DSD_U16_LE, + [VIRTIO_SND_PCM_FMT_DSD_U32] = SNDRV_PCM_FORMAT_DSD_U32_LE, + [VIRTIO_SND_PCM_FMT_IEC958_SUBFRAME] = + SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE +}; + +/* Map for converting VirtIO frame rate to ALSA frame rate. */ +struct virtsnd_v2a_rate { + unsigned int alsa_bit; + unsigned int rate; +}; + +static const struct virtsnd_v2a_rate g_v2a_rate_map[] = { + [VIRTIO_SND_PCM_RATE_5512] = { SNDRV_PCM_RATE_5512, 5512 }, + [VIRTIO_SND_PCM_RATE_8000] = { SNDRV_PCM_RATE_8000, 8000 }, + [VIRTIO_SND_PCM_RATE_11025] = { SNDRV_PCM_RATE_11025, 11025 }, + [VIRTIO_SND_PCM_RATE_16000] = { SNDRV_PCM_RATE_16000, 16000 }, + [VIRTIO_SND_PCM_RATE_22050] = { SNDRV_PCM_RATE_22050, 22050 }, + [VIRTIO_SND_PCM_RATE_32000] = { SNDRV_PCM_RATE_32000, 32000 }, + [VIRTIO_SND_PCM_RATE_44100] = { SNDRV_PCM_RATE_44100, 44100 }, + [VIRTIO_SND_PCM_RATE_48000] = { SNDRV_PCM_RATE_48000, 48000 }, + [VIRTIO_SND_PCM_RATE_64000] = { SNDRV_PCM_RATE_64000, 64000 }, + [VIRTIO_SND_PCM_RATE_88200] = { SNDRV_PCM_RATE_88200, 88200 }, + [VIRTIO_SND_PCM_RATE_96000] = { SNDRV_PCM_RATE_96000, 96000 }, + [VIRTIO_SND_PCM_RATE_176400] = { SNDRV_PCM_RATE_176400, 176400 }, + [VIRTIO_SND_PCM_RATE_192000] = { SNDRV_PCM_RATE_192000, 192000 } +}; + +/** + * virtsnd_pcm_build_hw() - Parse substream config and build HW descriptor. + * @vss: VirtIO substream. + * @info: VirtIO substream information entry. + * + * Context: Any context. + * Return: 0 on success, -EINVAL if configuration is invalid. + */ +static int virtsnd_pcm_build_hw(struct virtio_pcm_substream *vss, + struct virtio_snd_pcm_info *info) +{ + struct virtio_device *vdev = vss->snd->vdev; + unsigned int i; + u64 values; + size_t sample_max = 0; + size_t sample_min = 0; + + vss->features = le32_to_cpu(info->features); + + /* + * TODO: set SNDRV_PCM_INFO_{BATCH,BLOCK_TRANSFER} if device supports + * only message-based transport. + */ + vss->hw.info = + SNDRV_PCM_INFO_MMAP | + SNDRV_PCM_INFO_MMAP_VALID | + SNDRV_PCM_INFO_BATCH | + SNDRV_PCM_INFO_BLOCK_TRANSFER | + SNDRV_PCM_INFO_INTERLEAVED | + SNDRV_PCM_INFO_PAUSE; + + if (!info->channels_min || info->channels_min > info->channels_max) { + dev_err(&vdev->dev, + "SID %u: invalid channel range [%u %u]\n", + vss->sid, info->channels_min, info->channels_max); + return -EINVAL; + } + + vss->hw.channels_min = info->channels_min; + vss->hw.channels_max = info->channels_max; + + values = le64_to_cpu(info->formats); + + vss->hw.formats = 0; + + for (i = 0; i < ARRAY_SIZE(g_v2a_format_map); ++i) + if (values & (1ULL << i)) { + unsigned int alsa_fmt = g_v2a_format_map[i]; + int bytes = snd_pcm_format_physical_width(alsa_fmt) / 8; + + if (!sample_min || sample_min > bytes) + sample_min = bytes; + + if (sample_max < bytes) + sample_max = bytes; + + vss->hw.formats |= (1ULL << alsa_fmt); + } + + if (!vss->hw.formats) { + dev_err(&vdev->dev, + "SID %u: no supported PCM sample formats found\n", + vss->sid); + return -EINVAL; + } + + values = le64_to_cpu(info->rates); + + vss->hw.rates = 0; + + for (i = 0; i < ARRAY_SIZE(g_v2a_rate_map); ++i) + if (values & (1ULL << i)) { + if (!vss->hw.rate_min || + vss->hw.rate_min > g_v2a_rate_map[i].rate) + vss->hw.rate_min = g_v2a_rate_map[i].rate; + + if (vss->hw.rate_max < g_v2a_rate_map[i].rate) + vss->hw.rate_max = g_v2a_rate_map[i].rate; + + vss->hw.rates |= g_v2a_rate_map[i].alsa_bit; + } + + if (!vss->hw.rates) { + dev_err(&vdev->dev, + "SID %u: no supported PCM frame rates found\n", + vss->sid); + return -EINVAL; + } + + vss->hw.periods_min = pcm_periods_min; + vss->hw.periods_max = pcm_periods_max; + + /* + * We must ensure that there is enough space in the buffer to store + * pcm_buffer_ms ms for the combination (Cmax, Smax, Rmax), where: + * Cmax = maximum supported number of channels, + * Smax = maximum supported sample size in bytes, + * Rmax = maximum supported frame rate. + */ + vss->hw.buffer_bytes_max = + sample_max * vss->hw.channels_max * pcm_buffer_ms * + (vss->hw.rate_max / MSEC_PER_SEC); + + /* Align the buffer size to the page size */ + vss->hw.buffer_bytes_max = + (vss->hw.buffer_bytes_max + PAGE_SIZE - 1) & -PAGE_SIZE; + + /* + * We must ensure that the minimum period size is enough to store + * pcm_period_ms_min ms for the combination (Cmin, Smin, Rmin), where: + * Cmin = minimum supported number of channels, + * Smin = minimum supported sample size in bytes, + * Rmin = minimum supported frame rate. + */ + vss->hw.period_bytes_min = + sample_min * vss->hw.channels_min * pcm_period_ms_min * + (vss->hw.rate_min / MSEC_PER_SEC); + + /* + * We must ensure that the maximum period size is enough to store + * pcm_period_ms_max ms for the combination (Cmax, Smax, Rmax). + */ + vss->hw.period_bytes_max = + sample_max * vss->hw.channels_max * pcm_period_ms_max * + (vss->hw.rate_max / MSEC_PER_SEC); + + return 0; +} + +/** + * virtsnd_pcm_find() - Find the PCM device for the specified node ID. + * @snd: VirtIO sound device. + * @nid: Function node ID. + * + * Context: Any context. + * Return: a pointer to the PCM device or ERR_PTR(-ENOENT). + */ +struct virtio_pcm *virtsnd_pcm_find(struct virtio_snd *snd, unsigned int nid) +{ + struct virtio_pcm *vpcm; + + list_for_each_entry(vpcm, &snd->pcm_list, list) + if (vpcm->nid == nid) + return vpcm; + + return ERR_PTR(-ENOENT); +} + +/** + * virtsnd_pcm_find_or_create() - Find or create the PCM device for the + * specified node ID. + * @snd: VirtIO sound device. + * @nid: Function node ID. + * + * Context: Any context that permits to sleep. + * Return: a pointer to the PCM device or ERR_PTR(-errno). + */ +struct virtio_pcm *virtsnd_pcm_find_or_create(struct virtio_snd *snd, + unsigned int nid) +{ + struct virtio_device *vdev = snd->vdev; + struct virtio_pcm *vpcm; + + vpcm = virtsnd_pcm_find(snd, nid); + if (!IS_ERR(vpcm)) + return vpcm; + + vpcm = devm_kzalloc(&vdev->dev, sizeof(*vpcm), GFP_KERNEL); + if (!vpcm) + return ERR_PTR(-ENOMEM); + + vpcm->nid = nid; + list_add_tail(&vpcm->list, &snd->pcm_list); + + return vpcm; +} + +/** + * virtsnd_pcm_validate() - Validate if the device can be started. + * @vdev: VirtIO parent device. + * + * Context: Any context. + * Return: 0 on success, -EINVAL on failure. + */ +int virtsnd_pcm_validate(struct virtio_device *vdev) +{ + if (pcm_periods_min < 2 || pcm_periods_min > pcm_periods_max) { + dev_err(&vdev->dev, + "invalid range [%u %u] of the number of PCM periods\n", + pcm_periods_min, pcm_periods_max); + return -EINVAL; + } + + if (!pcm_period_ms_min || pcm_period_ms_min > pcm_period_ms_max) { + dev_err(&vdev->dev, + "invalid range [%u %u] of the size of the PCM period\n", + pcm_period_ms_min, pcm_period_ms_max); + return -EINVAL; + } + + if (pcm_buffer_ms < pcm_periods_min * pcm_period_ms_min) { + dev_err(&vdev->dev, + "pcm_buffer_ms(=%u) value cannot be < %u ms\n", + pcm_buffer_ms, pcm_periods_min * pcm_period_ms_min); + return -EINVAL; + } + + if (pcm_period_ms_max > pcm_buffer_ms / 2) { + dev_err(&vdev->dev, + "pcm_period_ms_max(=%u) value cannot be > %u ms\n", + pcm_period_ms_max, pcm_buffer_ms / 2); + return -EINVAL; + } + + return 0; +} + +/** + * virtsnd_pcm_parse_cfg() - Parse the stream configuration. + * @snd: VirtIO sound device. + * + * This function is called during initial device initialization. + * + * Context: Any context that permits to sleep. + * Return: 0 on success, -errno on failure. + */ +int virtsnd_pcm_parse_cfg(struct virtio_snd *snd) +{ + struct virtio_device *vdev = snd->vdev; + struct virtio_snd_pcm_info *info; + unsigned int i; + int rc; + + virtio_cread(vdev, struct virtio_snd_config, streams, + &snd->nsubstreams); + if (!snd->nsubstreams) + return 0; + + snd->substreams = devm_kcalloc(&vdev->dev, snd->nsubstreams, + sizeof(*snd->substreams), GFP_KERNEL); + if (!snd->substreams) + return -ENOMEM; + + info = kcalloc(snd->nsubstreams, sizeof(*info), GFP_KERNEL); + if (!info) + return -ENOMEM; + + rc = virtsnd_ctl_query_info(snd, VIRTIO_SND_R_PCM_INFO, 0, + snd->nsubstreams, sizeof(*info), info); + if (rc) + goto on_exit; + + for (i = 0; i < snd->nsubstreams; ++i) { + struct virtio_pcm_substream *vss = &snd->substreams[i]; + struct virtio_pcm *vpcm; + + vss->snd = snd; + vss->sid = i; + + rc = virtsnd_pcm_build_hw(vss, &info[i]); + if (rc) + goto on_exit; + + vss->nid = le32_to_cpu(info[i].hdr.hda_fn_nid); + + vpcm = virtsnd_pcm_find_or_create(snd, vss->nid); + if (IS_ERR(vpcm)) { + rc = PTR_ERR(vpcm); + goto on_exit; + } + + switch (info[i].direction) { + case VIRTIO_SND_D_OUTPUT: + vss->direction = SNDRV_PCM_STREAM_PLAYBACK; + break; + case VIRTIO_SND_D_INPUT: + vss->direction = SNDRV_PCM_STREAM_CAPTURE; + break; + default: + dev_err(&vdev->dev, "SID %u: unknown direction (%u)\n", + vss->sid, info[i].direction); + rc = -EINVAL; + goto on_exit; + } + + vpcm->streams[vss->direction].nsubstreams++; + } + +on_exit: + kfree(info); + + return rc; +} + +/** + * virtsnd_pcm_build_devs() - Build ALSA PCM devices. + * @snd: VirtIO sound device. + * + * Context: Any context that permits to sleep. + * Return: 0 on success, -errno on failure. + */ +int virtsnd_pcm_build_devs(struct virtio_snd *snd) +{ + struct virtio_device *vdev = snd->vdev; + struct virtio_pcm *vpcm; + unsigned int i; + int rc; + + list_for_each_entry(vpcm, &snd->pcm_list, list) { + unsigned int npbs = + vpcm->streams[SNDRV_PCM_STREAM_PLAYBACK].nsubstreams; + unsigned int ncps = + vpcm->streams[SNDRV_PCM_STREAM_CAPTURE].nsubstreams; + + if (!npbs && !ncps) + continue; + + rc = snd_pcm_new(snd->card, VIRTIO_SND_CARD_DRIVER, vpcm->nid, + npbs, ncps, &vpcm->pcm); + if (rc) { + dev_err(&vdev->dev, "snd_pcm_new[%u] failed: %d\n", + vpcm->nid, rc); + return rc; + } + + vpcm->pcm->info_flags = 0; + vpcm->pcm->dev_class = SNDRV_PCM_CLASS_GENERIC; + vpcm->pcm->dev_subclass = SNDRV_PCM_SUBCLASS_GENERIC_MIX; + snprintf(vpcm->pcm->name, sizeof(vpcm->pcm->name), + VIRTIO_SND_PCM_NAME " %u", vpcm->pcm->device); + vpcm->pcm->private_data = vpcm; + vpcm->pcm->nonatomic = true; + + for (i = 0; i < ARRAY_SIZE(vpcm->streams); ++i) { + struct virtio_pcm_stream *stream = &vpcm->streams[i]; + + if (!stream->nsubstreams) + continue; + + stream->substreams = + devm_kcalloc(&vdev->dev, stream->nsubstreams, + sizeof(*stream->substreams), + GFP_KERNEL); + if (!stream->substreams) + return -ENOMEM; + + stream->nsubstreams = 0; + } + } + + for (i = 0; i < snd->nsubstreams; ++i) { + struct virtio_pcm_stream *vs; + struct virtio_pcm_substream *vss = &snd->substreams[i]; + + vpcm = virtsnd_pcm_find(snd, vss->nid); + if (IS_ERR(vpcm)) + return PTR_ERR(vpcm); + + vs = &vpcm->streams[vss->direction]; + vs->substreams[vs->nsubstreams++] = vss; + } + + list_for_each_entry(vpcm, &snd->pcm_list, list) { + for (i = 0; i < ARRAY_SIZE(vpcm->streams); ++i) { + struct virtio_pcm_stream *vs = &vpcm->streams[i]; + struct snd_pcm_str *ks = &vpcm->pcm->streams[i]; + struct snd_pcm_substream *kss; + + if (!vs->nsubstreams) + continue; + + for (kss = ks->substream; kss; kss = kss->next) + vs->substreams[kss->number]->substream = kss; + } + + snd_pcm_set_managed_buffer_all(vpcm->pcm, + SNDRV_DMA_TYPE_VMALLOC, NULL, + 0, 0); + } + + return 0; +} diff --git a/sound/virtio/virtio_pcm.h b/sound/virtio/virtio_pcm.h new file mode 100644 index 000000000000..42d592da41e5 --- /dev/null +++ b/sound/virtio/virtio_pcm.h @@ -0,0 +1,71 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * virtio-snd: Virtio sound device + * Copyright (C) 2021 OpenSynergy GmbH + */ +#ifndef VIRTIO_SND_PCM_H +#define VIRTIO_SND_PCM_H + +#include <linux/atomic.h> +#include <linux/virtio_config.h> +#include <sound/pcm.h> + +struct virtio_pcm; +struct virtio_pcm_msg; + +/** + * struct virtio_pcm_substream - VirtIO PCM substream. + * @snd: VirtIO sound device. + * @nid: Function group node identifier. + * @sid: Stream identifier. + * @direction: Stream data flow direction (SNDRV_PCM_STREAM_XXX). + * @features: Stream VirtIO feature bit map (1 << VIRTIO_SND_PCM_F_XXX). + * @substream: Kernel ALSA substream. + * @hw: Kernel ALSA substream hardware descriptor. + */ +struct virtio_pcm_substream { + struct virtio_snd *snd; + unsigned int nid; + unsigned int sid; + u32 direction; + u32 features; + struct snd_pcm_substream *substream; + struct snd_pcm_hardware hw; +}; + +/** + * struct virtio_pcm_stream - VirtIO PCM stream. + * @substreams: VirtIO substreams belonging to the stream. + * @nsubstreams: Number of substreams. + */ +struct virtio_pcm_stream { + struct virtio_pcm_substream **substreams; + unsigned int nsubstreams; +}; + +/** + * struct virtio_pcm - VirtIO PCM device. + * @list: VirtIO PCM list entry. + * @nid: Function group node identifier. + * @pcm: Kernel PCM device. + * @streams: VirtIO PCM streams (playback and capture). + */ +struct virtio_pcm { + struct list_head list; + unsigned int nid; + struct snd_pcm *pcm; + struct virtio_pcm_stream streams[SNDRV_PCM_STREAM_LAST + 1]; +}; + +int virtsnd_pcm_validate(struct virtio_device *vdev); + +int virtsnd_pcm_parse_cfg(struct virtio_snd *snd); + +int virtsnd_pcm_build_devs(struct virtio_snd *snd); + +struct virtio_pcm *virtsnd_pcm_find(struct virtio_snd *snd, unsigned int nid); + +struct virtio_pcm *virtsnd_pcm_find_or_create(struct virtio_snd *snd, + unsigned int nid); + +#endif /* VIRTIO_SND_PCM_H */