summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--MAINTAINERS9
-rw-r--r--include/uapi/linux/virtio_snd.h334
-rw-r--r--sound/Kconfig2
-rw-r--r--sound/Makefile3
-rw-r--r--sound/virtio/Kconfig10
-rw-r--r--sound/virtio/Makefile7
-rw-r--r--sound/virtio/virtio_card.c324
-rw-r--r--sound/virtio/virtio_card.h65
8 files changed, 753 insertions, 1 deletions
diff --git a/MAINTAINERS b/MAINTAINERS
index d92f85ca831d..a68c543c28f1 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -19086,6 +19086,15 @@ W: https://virtio-mem.gitlab.io/
F: drivers/virtio/virtio_mem.c
F: include/uapi/linux/virtio_mem.h
+VIRTIO SOUND DRIVER
+M: Anton Yakovlev <anton.yakovlev@opensynergy.com>
+M: "Michael S. Tsirkin" <mst@redhat.com>
+L: virtualization@lists.linux-foundation.org
+L: alsa-devel@alsa-project.org (moderated for non-subscribers)
+S: Maintained
+F: include/uapi/linux/virtio_snd.h
+F: sound/virtio/*
+
VIRTUAL BOX GUEST DEVICE DRIVER
M: Hans de Goede <hdegoede@redhat.com>
M: Arnd Bergmann <arnd@arndb.de>
diff --git a/include/uapi/linux/virtio_snd.h b/include/uapi/linux/virtio_snd.h
new file mode 100644
index 000000000000..dfe49547a7b0
--- /dev/null
+++ b/include/uapi/linux/virtio_snd.h
@@ -0,0 +1,334 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Copyright (C) 2021 OpenSynergy GmbH
+ */
+#ifndef VIRTIO_SND_IF_H
+#define VIRTIO_SND_IF_H
+
+#include <linux/virtio_types.h>
+
+/*******************************************************************************
+ * CONFIGURATION SPACE
+ */
+struct virtio_snd_config {
+ /* # of available physical jacks */
+ __le32 jacks;
+ /* # of available PCM streams */
+ __le32 streams;
+ /* # of available channel maps */
+ __le32 chmaps;
+};
+
+enum {
+ /* device virtqueue indexes */
+ VIRTIO_SND_VQ_CONTROL = 0,
+ VIRTIO_SND_VQ_EVENT,
+ VIRTIO_SND_VQ_TX,
+ VIRTIO_SND_VQ_RX,
+ /* # of device virtqueues */
+ VIRTIO_SND_VQ_MAX
+};
+
+/*******************************************************************************
+ * COMMON DEFINITIONS
+ */
+
+/* supported dataflow directions */
+enum {
+ VIRTIO_SND_D_OUTPUT = 0,
+ VIRTIO_SND_D_INPUT
+};
+
+enum {
+ /* jack control request types */
+ VIRTIO_SND_R_JACK_INFO = 1,
+ VIRTIO_SND_R_JACK_REMAP,
+
+ /* PCM control request types */
+ VIRTIO_SND_R_PCM_INFO = 0x0100,
+ VIRTIO_SND_R_PCM_SET_PARAMS,
+ VIRTIO_SND_R_PCM_PREPARE,
+ VIRTIO_SND_R_PCM_RELEASE,
+ VIRTIO_SND_R_PCM_START,
+ VIRTIO_SND_R_PCM_STOP,
+
+ /* channel map control request types */
+ VIRTIO_SND_R_CHMAP_INFO = 0x0200,
+
+ /* jack event types */
+ VIRTIO_SND_EVT_JACK_CONNECTED = 0x1000,
+ VIRTIO_SND_EVT_JACK_DISCONNECTED,
+
+ /* PCM event types */
+ VIRTIO_SND_EVT_PCM_PERIOD_ELAPSED = 0x1100,
+ VIRTIO_SND_EVT_PCM_XRUN,
+
+ /* common status codes */
+ VIRTIO_SND_S_OK = 0x8000,
+ VIRTIO_SND_S_BAD_MSG,
+ VIRTIO_SND_S_NOT_SUPP,
+ VIRTIO_SND_S_IO_ERR
+};
+
+/* common header */
+struct virtio_snd_hdr {
+ __le32 code;
+};
+
+/* event notification */
+struct virtio_snd_event {
+ /* VIRTIO_SND_EVT_XXX */
+ struct virtio_snd_hdr hdr;
+ /* optional event data */
+ __le32 data;
+};
+
+/* common control request to query an item information */
+struct virtio_snd_query_info {
+ /* VIRTIO_SND_R_XXX_INFO */
+ struct virtio_snd_hdr hdr;
+ /* item start identifier */
+ __le32 start_id;
+ /* item count to query */
+ __le32 count;
+ /* item information size in bytes */
+ __le32 size;
+};
+
+/* common item information header */
+struct virtio_snd_info {
+ /* function group node id (High Definition Audio Specification 7.1.2) */
+ __le32 hda_fn_nid;
+};
+
+/*******************************************************************************
+ * JACK CONTROL MESSAGES
+ */
+struct virtio_snd_jack_hdr {
+ /* VIRTIO_SND_R_JACK_XXX */
+ struct virtio_snd_hdr hdr;
+ /* 0 ... virtio_snd_config::jacks - 1 */
+ __le32 jack_id;
+};
+
+/* supported jack features */
+enum {
+ VIRTIO_SND_JACK_F_REMAP = 0
+};
+
+struct virtio_snd_jack_info {
+ /* common header */
+ struct virtio_snd_info hdr;
+ /* supported feature bit map (1 << VIRTIO_SND_JACK_F_XXX) */
+ __le32 features;
+ /* pin configuration (High Definition Audio Specification 7.3.3.31) */
+ __le32 hda_reg_defconf;
+ /* pin capabilities (High Definition Audio Specification 7.3.4.9) */
+ __le32 hda_reg_caps;
+ /* current jack connection status (0: disconnected, 1: connected) */
+ __u8 connected;
+
+ __u8 padding[7];
+};
+
+/* jack remapping control request */
+struct virtio_snd_jack_remap {
+ /* .code = VIRTIO_SND_R_JACK_REMAP */
+ struct virtio_snd_jack_hdr hdr;
+ /* selected association number */
+ __le32 association;
+ /* selected sequence number */
+ __le32 sequence;
+};
+
+/*******************************************************************************
+ * PCM CONTROL MESSAGES
+ */
+struct virtio_snd_pcm_hdr {
+ /* VIRTIO_SND_R_PCM_XXX */
+ struct virtio_snd_hdr hdr;
+ /* 0 ... virtio_snd_config::streams - 1 */
+ __le32 stream_id;
+};
+
+/* supported PCM stream features */
+enum {
+ VIRTIO_SND_PCM_F_SHMEM_HOST = 0,
+ VIRTIO_SND_PCM_F_SHMEM_GUEST,
+ VIRTIO_SND_PCM_F_MSG_POLLING,
+ VIRTIO_SND_PCM_F_EVT_SHMEM_PERIODS,
+ VIRTIO_SND_PCM_F_EVT_XRUNS
+};
+
+/* supported PCM sample formats */
+enum {
+ /* analog formats (width / physical width) */
+ VIRTIO_SND_PCM_FMT_IMA_ADPCM = 0, /* 4 / 4 bits */
+ VIRTIO_SND_PCM_FMT_MU_LAW, /* 8 / 8 bits */
+ VIRTIO_SND_PCM_FMT_A_LAW, /* 8 / 8 bits */
+ VIRTIO_SND_PCM_FMT_S8, /* 8 / 8 bits */
+ VIRTIO_SND_PCM_FMT_U8, /* 8 / 8 bits */
+ VIRTIO_SND_PCM_FMT_S16, /* 16 / 16 bits */
+ VIRTIO_SND_PCM_FMT_U16, /* 16 / 16 bits */
+ VIRTIO_SND_PCM_FMT_S18_3, /* 18 / 24 bits */
+ VIRTIO_SND_PCM_FMT_U18_3, /* 18 / 24 bits */
+ VIRTIO_SND_PCM_FMT_S20_3, /* 20 / 24 bits */
+ VIRTIO_SND_PCM_FMT_U20_3, /* 20 / 24 bits */
+ VIRTIO_SND_PCM_FMT_S24_3, /* 24 / 24 bits */
+ VIRTIO_SND_PCM_FMT_U24_3, /* 24 / 24 bits */
+ VIRTIO_SND_PCM_FMT_S20, /* 20 / 32 bits */
+ VIRTIO_SND_PCM_FMT_U20, /* 20 / 32 bits */
+ VIRTIO_SND_PCM_FMT_S24, /* 24 / 32 bits */
+ VIRTIO_SND_PCM_FMT_U24, /* 24 / 32 bits */
+ VIRTIO_SND_PCM_FMT_S32, /* 32 / 32 bits */
+ VIRTIO_SND_PCM_FMT_U32, /* 32 / 32 bits */
+ VIRTIO_SND_PCM_FMT_FLOAT, /* 32 / 32 bits */
+ VIRTIO_SND_PCM_FMT_FLOAT64, /* 64 / 64 bits */
+ /* digital formats (width / physical width) */
+ VIRTIO_SND_PCM_FMT_DSD_U8, /* 8 / 8 bits */
+ VIRTIO_SND_PCM_FMT_DSD_U16, /* 16 / 16 bits */
+ VIRTIO_SND_PCM_FMT_DSD_U32, /* 32 / 32 bits */
+ VIRTIO_SND_PCM_FMT_IEC958_SUBFRAME /* 32 / 32 bits */
+};
+
+/* supported PCM frame rates */
+enum {
+ VIRTIO_SND_PCM_RATE_5512 = 0,
+ VIRTIO_SND_PCM_RATE_8000,
+ VIRTIO_SND_PCM_RATE_11025,
+ VIRTIO_SND_PCM_RATE_16000,
+ VIRTIO_SND_PCM_RATE_22050,
+ VIRTIO_SND_PCM_RATE_32000,
+ VIRTIO_SND_PCM_RATE_44100,
+ VIRTIO_SND_PCM_RATE_48000,
+ VIRTIO_SND_PCM_RATE_64000,
+ VIRTIO_SND_PCM_RATE_88200,
+ VIRTIO_SND_PCM_RATE_96000,
+ VIRTIO_SND_PCM_RATE_176400,
+ VIRTIO_SND_PCM_RATE_192000,
+ VIRTIO_SND_PCM_RATE_384000
+};
+
+struct virtio_snd_pcm_info {
+ /* common header */
+ struct virtio_snd_info hdr;
+ /* supported feature bit map (1 << VIRTIO_SND_PCM_F_XXX) */
+ __le32 features;
+ /* supported sample format bit map (1 << VIRTIO_SND_PCM_FMT_XXX) */
+ __le64 formats;
+ /* supported frame rate bit map (1 << VIRTIO_SND_PCM_RATE_XXX) */
+ __le64 rates;
+ /* dataflow direction (VIRTIO_SND_D_XXX) */
+ __u8 direction;
+ /* minimum # of supported channels */
+ __u8 channels_min;
+ /* maximum # of supported channels */
+ __u8 channels_max;
+
+ __u8 padding[5];
+};
+
+/* set PCM stream format */
+struct virtio_snd_pcm_set_params {
+ /* .code = VIRTIO_SND_R_PCM_SET_PARAMS */
+ struct virtio_snd_pcm_hdr hdr;
+ /* size of the hardware buffer */
+ __le32 buffer_bytes;
+ /* size of the hardware period */
+ __le32 period_bytes;
+ /* selected feature bit map (1 << VIRTIO_SND_PCM_F_XXX) */
+ __le32 features;
+ /* selected # of channels */
+ __u8 channels;
+ /* selected sample format (VIRTIO_SND_PCM_FMT_XXX) */
+ __u8 format;
+ /* selected frame rate (VIRTIO_SND_PCM_RATE_XXX) */
+ __u8 rate;
+
+ __u8 padding;
+};
+
+/*******************************************************************************
+ * PCM I/O MESSAGES
+ */
+
+/* I/O request header */
+struct virtio_snd_pcm_xfer {
+ /* 0 ... virtio_snd_config::streams - 1 */
+ __le32 stream_id;
+};
+
+/* I/O request status */
+struct virtio_snd_pcm_status {
+ /* VIRTIO_SND_S_XXX */
+ __le32 status;
+ /* current device latency */
+ __le32 latency_bytes;
+};
+
+/*******************************************************************************
+ * CHANNEL MAP CONTROL MESSAGES
+ */
+struct virtio_snd_chmap_hdr {
+ /* VIRTIO_SND_R_CHMAP_XXX */
+ struct virtio_snd_hdr hdr;
+ /* 0 ... virtio_snd_config::chmaps - 1 */
+ __le32 chmap_id;
+};
+
+/* standard channel position definition */
+enum {
+ VIRTIO_SND_CHMAP_NONE = 0, /* undefined */
+ VIRTIO_SND_CHMAP_NA, /* silent */
+ VIRTIO_SND_CHMAP_MONO, /* mono stream */
+ VIRTIO_SND_CHMAP_FL, /* front left */
+ VIRTIO_SND_CHMAP_FR, /* front right */
+ VIRTIO_SND_CHMAP_RL, /* rear left */
+ VIRTIO_SND_CHMAP_RR, /* rear right */
+ VIRTIO_SND_CHMAP_FC, /* front center */
+ VIRTIO_SND_CHMAP_LFE, /* low frequency (LFE) */
+ VIRTIO_SND_CHMAP_SL, /* side left */
+ VIRTIO_SND_CHMAP_SR, /* side right */
+ VIRTIO_SND_CHMAP_RC, /* rear center */
+ VIRTIO_SND_CHMAP_FLC, /* front left center */
+ VIRTIO_SND_CHMAP_FRC, /* front right center */
+ VIRTIO_SND_CHMAP_RLC, /* rear left center */
+ VIRTIO_SND_CHMAP_RRC, /* rear right center */
+ VIRTIO_SND_CHMAP_FLW, /* front left wide */
+ VIRTIO_SND_CHMAP_FRW, /* front right wide */
+ VIRTIO_SND_CHMAP_FLH, /* front left high */
+ VIRTIO_SND_CHMAP_FCH, /* front center high */
+ VIRTIO_SND_CHMAP_FRH, /* front right high */
+ VIRTIO_SND_CHMAP_TC, /* top center */
+ VIRTIO_SND_CHMAP_TFL, /* top front left */
+ VIRTIO_SND_CHMAP_TFR, /* top front right */
+ VIRTIO_SND_CHMAP_TFC, /* top front center */
+ VIRTIO_SND_CHMAP_TRL, /* top rear left */
+ VIRTIO_SND_CHMAP_TRR, /* top rear right */
+ VIRTIO_SND_CHMAP_TRC, /* top rear center */
+ VIRTIO_SND_CHMAP_TFLC, /* top front left center */
+ VIRTIO_SND_CHMAP_TFRC, /* top front right center */
+ VIRTIO_SND_CHMAP_TSL, /* top side left */
+ VIRTIO_SND_CHMAP_TSR, /* top side right */
+ VIRTIO_SND_CHMAP_LLFE, /* left LFE */
+ VIRTIO_SND_CHMAP_RLFE, /* right LFE */
+ VIRTIO_SND_CHMAP_BC, /* bottom center */
+ VIRTIO_SND_CHMAP_BLC, /* bottom left center */
+ VIRTIO_SND_CHMAP_BRC /* bottom right center */
+};
+
+/* maximum possible number of channels */
+#define VIRTIO_SND_CHMAP_MAX_SIZE 18
+
+struct virtio_snd_chmap_info {
+ /* common header */
+ struct virtio_snd_info hdr;
+ /* dataflow direction (VIRTIO_SND_D_XXX) */
+ __u8 direction;
+ /* # of valid channel position values */
+ __u8 channels;
+ /* channel position values (VIRTIO_SND_CHMAP_XXX) */
+ __u8 positions[VIRTIO_SND_CHMAP_MAX_SIZE];
+};
+
+#endif /* VIRTIO_SND_IF_H */
diff --git a/sound/Kconfig b/sound/Kconfig
index 36785410fbe1..e56d96d2b11c 100644
--- a/sound/Kconfig
+++ b/sound/Kconfig
@@ -99,6 +99,8 @@ source "sound/synth/Kconfig"
source "sound/xen/Kconfig"
+source "sound/virtio/Kconfig"
+
endif # SND
endif # !UML
diff --git a/sound/Makefile b/sound/Makefile
index 797ecdcd35e2..04ef04b1168f 100644
--- a/sound/Makefile
+++ b/sound/Makefile
@@ -5,7 +5,8 @@
obj-$(CONFIG_SOUND) += soundcore.o
obj-$(CONFIG_DMASOUND) += oss/dmasound/
obj-$(CONFIG_SND) += core/ i2c/ drivers/ isa/ pci/ ppc/ arm/ sh/ synth/ usb/ \
- firewire/ sparc/ spi/ parisc/ pcmcia/ mips/ soc/ atmel/ hda/ x86/ xen/
+ firewire/ sparc/ spi/ parisc/ pcmcia/ mips/ soc/ atmel/ hda/ x86/ xen/ \
+ virtio/
obj-$(CONFIG_SND_AOA) += aoa/
# This one must be compilable even if sound is configured out
diff --git a/sound/virtio/Kconfig b/sound/virtio/Kconfig
new file mode 100644
index 000000000000..094cba24ee5b
--- /dev/null
+++ b/sound/virtio/Kconfig
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0+
+# Sound card driver for virtio
+
+config SND_VIRTIO
+ tristate "Virtio sound driver"
+ depends on VIRTIO
+ select SND_PCM
+ select SND_JACK
+ help
+ This is the virtual sound driver for virtio. Say Y or M.
diff --git a/sound/virtio/Makefile b/sound/virtio/Makefile
new file mode 100644
index 000000000000..8c87ebb9982b
--- /dev/null
+++ b/sound/virtio/Makefile
@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: GPL-2.0+
+
+obj-$(CONFIG_SND_VIRTIO) += virtio_snd.o
+
+virtio_snd-objs := \
+ virtio_card.o
+
diff --git a/sound/virtio/virtio_card.c b/sound/virtio/virtio_card.c
new file mode 100644
index 000000000000..5a37056858e9
--- /dev/null
+++ b/sound/virtio/virtio_card.c
@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * virtio-snd: Virtio sound device
+ * Copyright (C) 2021 OpenSynergy GmbH
+ */
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/virtio_config.h>
+#include <sound/initval.h>
+#include <uapi/linux/virtio_ids.h>
+
+#include "virtio_card.h"
+
+static void virtsnd_remove(struct virtio_device *vdev);
+
+/**
+ * virtsnd_event_send() - Add an event to the event queue.
+ * @vqueue: Underlying event virtqueue.
+ * @event: Event.
+ * @notify: Indicates whether or not to send a notification to the device.
+ * @gfp: Kernel flags for memory allocation.
+ *
+ * Context: Any context.
+ */
+static void virtsnd_event_send(struct virtqueue *vqueue,
+ struct virtio_snd_event *event, bool notify,
+ gfp_t gfp)
+{
+ struct scatterlist sg;
+ struct scatterlist *psgs[1] = { &sg };
+
+ /* reset event content */
+ memset(event, 0, sizeof(*event));
+
+ sg_init_one(&sg, event, sizeof(*event));
+
+ if (virtqueue_add_sgs(vqueue, psgs, 0, 1, event, gfp) || !notify)
+ return;
+
+ if (virtqueue_kick_prepare(vqueue))
+ virtqueue_notify(vqueue);
+}
+
+/**
+ * virtsnd_event_dispatch() - Dispatch an event from the device side.
+ * @snd: VirtIO sound device.
+ * @event: VirtIO sound event.
+ *
+ * Context: Any context.
+ */
+static void virtsnd_event_dispatch(struct virtio_snd *snd,
+ struct virtio_snd_event *event)
+{
+}
+
+/**
+ * virtsnd_event_notify_cb() - Dispatch all reported events from the event queue.
+ * @vqueue: Underlying event virtqueue.
+ *
+ * This callback function is called upon a vring interrupt request from the
+ * device.
+ *
+ * Context: Interrupt context.
+ */
+static void virtsnd_event_notify_cb(struct virtqueue *vqueue)
+{
+ struct virtio_snd *snd = vqueue->vdev->priv;
+ struct virtio_snd_queue *queue = virtsnd_event_queue(snd);
+ struct virtio_snd_event *event;
+ u32 length;
+ unsigned long flags;
+
+ spin_lock_irqsave(&queue->lock, flags);
+ do {
+ virtqueue_disable_cb(vqueue);
+ while ((event = virtqueue_get_buf(vqueue, &length))) {
+ virtsnd_event_dispatch(snd, event);
+ virtsnd_event_send(vqueue, event, true, GFP_ATOMIC);
+ }
+ if (unlikely(virtqueue_is_broken(vqueue)))
+ break;
+ } while (!virtqueue_enable_cb(vqueue));
+ spin_unlock_irqrestore(&queue->lock, flags);
+}
+
+/**
+ * virtsnd_find_vqs() - Enumerate and initialize all virtqueues.
+ * @snd: VirtIO sound device.
+ *
+ * After calling this function, the event queue is disabled.
+ *
+ * Context: Any context.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_find_vqs(struct virtio_snd *snd)
+{
+ struct virtio_device *vdev = snd->vdev;
+ static vq_callback_t *callbacks[VIRTIO_SND_VQ_MAX] = {
+ [VIRTIO_SND_VQ_EVENT] = virtsnd_event_notify_cb
+ };
+ static const char *names[VIRTIO_SND_VQ_MAX] = {
+ [VIRTIO_SND_VQ_EVENT] = "virtsnd-event"
+ };
+ struct virtqueue *vqs[VIRTIO_SND_VQ_MAX] = { 0 };
+ unsigned int i;
+ unsigned int n;
+ int rc;
+
+ rc = virtio_find_vqs(vdev, VIRTIO_SND_VQ_MAX, vqs, callbacks, names,
+ NULL);
+ if (rc) {
+ dev_err(&vdev->dev, "failed to initialize virtqueues\n");
+ return rc;
+ }
+
+ for (i = 0; i < VIRTIO_SND_VQ_MAX; ++i)
+ snd->queues[i].vqueue = vqs[i];
+
+ /* Allocate events and populate the event queue */
+ virtqueue_disable_cb(vqs[VIRTIO_SND_VQ_EVENT]);
+
+ n = virtqueue_get_vring_size(vqs[VIRTIO_SND_VQ_EVENT]);
+
+ snd->event_msgs = kmalloc_array(n, sizeof(*snd->event_msgs),
+ GFP_KERNEL);
+ if (!snd->event_msgs)
+ return -ENOMEM;
+
+ for (i = 0; i < n; ++i)
+ virtsnd_event_send(vqs[VIRTIO_SND_VQ_EVENT],
+ &snd->event_msgs[i], false, GFP_KERNEL);
+
+ return 0;
+}
+
+/**
+ * virtsnd_enable_event_vq() - Enable the event virtqueue.
+ * @snd: VirtIO sound device.
+ *
+ * Context: Any context.
+ */
+static void virtsnd_enable_event_vq(struct virtio_snd *snd)
+{
+ struct virtio_snd_queue *queue = virtsnd_event_queue(snd);
+
+ if (!virtqueue_enable_cb(queue->vqueue))
+ virtsnd_event_notify_cb(queue->vqueue);
+}
+
+/**
+ * virtsnd_disable_event_vq() - Disable the event virtqueue.
+ * @snd: VirtIO sound device.
+ *
+ * Context: Any context.
+ */
+static void virtsnd_disable_event_vq(struct virtio_snd *snd)
+{
+ struct virtio_snd_queue *queue = virtsnd_event_queue(snd);
+ struct virtio_snd_event *event;
+ u32 length;
+ unsigned long flags;
+
+ if (queue->vqueue) {
+ spin_lock_irqsave(&queue->lock, flags);
+ virtqueue_disable_cb(queue->vqueue);
+ while ((event = virtqueue_get_buf(queue->vqueue, &length)))
+ virtsnd_event_dispatch(snd, event);
+ spin_unlock_irqrestore(&queue->lock, flags);
+ }
+}
+
+/**
+ * virtsnd_build_devs() - Read configuration and build ALSA devices.
+ * @snd: VirtIO sound device.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_build_devs(struct virtio_snd *snd)
+{
+ struct virtio_device *vdev = snd->vdev;
+ struct device *dev = &vdev->dev;
+ int rc;
+
+ rc = snd_card_new(dev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1,
+ THIS_MODULE, 0, &snd->card);
+ if (rc < 0)
+ return rc;
+
+ snd->card->private_data = snd;
+
+ strscpy(snd->card->driver, VIRTIO_SND_CARD_DRIVER,
+ sizeof(snd->card->driver));
+ strscpy(snd->card->shortname, VIRTIO_SND_CARD_NAME,
+ sizeof(snd->card->shortname));
+ if (dev->parent->bus)
+ snprintf(snd->card->longname, sizeof(snd->card->longname),
+ VIRTIO_SND_CARD_NAME " at %s/%s/%s",
+ dev->parent->bus->name, dev_name(dev->parent),
+ dev_name(dev));
+ else
+ snprintf(snd->card->longname, sizeof(snd->card->longname),
+ VIRTIO_SND_CARD_NAME " at %s/%s",
+ dev_name(dev->parent), dev_name(dev));
+
+ return snd_card_register(snd->card);
+}
+
+/**
+ * virtsnd_validate() - Validate if the device can be started.
+ * @vdev: VirtIO parent device.
+ *
+ * Context: Any context.
+ * Return: 0 on success, -EINVAL on failure.
+ */
+static int virtsnd_validate(struct virtio_device *vdev)
+{
+ if (!vdev->config->get) {
+ dev_err(&vdev->dev, "configuration access disabled\n");
+ return -EINVAL;
+ }
+
+ if (!virtio_has_feature(vdev, VIRTIO_F_VERSION_1)) {
+ dev_err(&vdev->dev,
+ "device does not comply with spec version 1.x\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * virtsnd_probe() - Create and initialize the device.
+ * @vdev: VirtIO parent device.
+ *
+ * Context: Any context that permits to sleep.
+ * Return: 0 on success, -errno on failure.
+ */
+static int virtsnd_probe(struct virtio_device *vdev)
+{
+ struct virtio_snd *snd;
+ unsigned int i;
+ int rc;
+
+ snd = devm_kzalloc(&vdev->dev, sizeof(*snd), GFP_KERNEL);
+ if (!snd)
+ return -ENOMEM;
+
+ snd->vdev = vdev;
+
+ vdev->priv = snd;
+
+ for (i = 0; i < VIRTIO_SND_VQ_MAX; ++i)
+ spin_lock_init(&snd->queues[i].lock);
+
+ rc = virtsnd_find_vqs(snd);
+ if (rc)
+ goto on_exit;
+
+ virtio_device_ready(vdev);
+
+ rc = virtsnd_build_devs(snd);
+ if (rc)
+ goto on_exit;
+
+ virtsnd_enable_event_vq(snd);
+
+on_exit:
+ if (rc)
+ virtsnd_remove(vdev);
+
+ return rc;
+}
+
+/**
+ * virtsnd_remove() - Remove VirtIO and ALSA devices.
+ * @vdev: VirtIO parent device.
+ *
+ * Context: Any context that permits to sleep.
+ */
+static void virtsnd_remove(struct virtio_device *vdev)
+{
+ struct virtio_snd *snd = vdev->priv;
+
+ virtsnd_disable_event_vq(snd);
+
+ if (snd->card)
+ snd_card_free(snd->card);
+
+ vdev->config->del_vqs(vdev);
+ vdev->config->reset(vdev);
+
+ kfree(snd->event_msgs);
+}
+
+static const struct virtio_device_id id_table[] = {
+ { VIRTIO_ID_SOUND, VIRTIO_DEV_ANY_ID },
+ { 0 },
+};
+
+static struct virtio_driver virtsnd_driver = {
+ .driver.name = KBUILD_MODNAME,
+ .driver.owner = THIS_MODULE,
+ .id_table = id_table,
+ .validate = virtsnd_validate,
+ .probe = virtsnd_probe,
+ .remove = virtsnd_remove,
+};
+
+static int __init init(void)
+{
+ return register_virtio_driver(&virtsnd_driver);
+}
+module_init(init);
+
+static void __exit fini(void)
+{
+ unregister_virtio_driver(&virtsnd_driver);
+}
+module_exit(fini);
+
+MODULE_DEVICE_TABLE(virtio, id_table);
+MODULE_DESCRIPTION("Virtio sound card driver");
+MODULE_LICENSE("GPL");
diff --git a/sound/virtio/virtio_card.h b/sound/virtio/virtio_card.h
new file mode 100644
index 000000000000..b903b1b12e90
--- /dev/null
+++ b/sound/virtio/virtio_card.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * virtio-snd: Virtio sound device
+ * Copyright (C) 2021 OpenSynergy GmbH
+ */
+#ifndef VIRTIO_SND_CARD_H
+#define VIRTIO_SND_CARD_H
+
+#include <linux/slab.h>
+#include <linux/virtio.h>
+#include <sound/core.h>
+#include <uapi/linux/virtio_snd.h>
+
+#define VIRTIO_SND_CARD_DRIVER "virtio-snd"
+#define VIRTIO_SND_CARD_NAME "VirtIO SoundCard"
+
+/**
+ * struct virtio_snd_queue - Virtqueue wrapper structure.
+ * @lock: Used to synchronize access to a virtqueue.
+ * @vqueue: Underlying virtqueue.
+ */
+struct virtio_snd_queue {
+ spinlock_t lock;
+ struct virtqueue *vqueue;
+};
+
+/**
+ * struct virtio_snd - VirtIO sound card device.
+ * @vdev: Underlying virtio device.
+ * @queues: Virtqueue wrappers.
+ * @card: ALSA sound card.
+ * @event_msgs: Device events.
+ */
+struct virtio_snd {
+ struct virtio_device *vdev;
+ struct virtio_snd_queue queues[VIRTIO_SND_VQ_MAX];
+ struct snd_card *card;
+ struct virtio_snd_event *event_msgs;
+};
+
+static inline struct virtio_snd_queue *
+virtsnd_control_queue(struct virtio_snd *snd)
+{
+ return &snd->queues[VIRTIO_SND_VQ_CONTROL];
+}
+
+static inline struct virtio_snd_queue *
+virtsnd_event_queue(struct virtio_snd *snd)
+{
+ return &snd->queues[VIRTIO_SND_VQ_EVENT];
+}
+
+static inline struct virtio_snd_queue *
+virtsnd_tx_queue(struct virtio_snd *snd)
+{
+ return &snd->queues[VIRTIO_SND_VQ_TX];
+}
+
+static inline struct virtio_snd_queue *
+virtsnd_rx_queue(struct virtio_snd *snd)
+{
+ return &snd->queues[VIRTIO_SND_VQ_RX];
+}
+
+#endif /* VIRTIO_SND_CARD_H */