linux/sound/virtio/virtio_card.c

// 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"

u32 virtsnd_msg_timeout_ms = …;
module_param_named(msg_timeout_ms, virtsnd_msg_timeout_ms, uint, 0644);
MODULE_PARM_DESC(…) …;

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)
{ … }

/**
 * 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)
{ … }

/**
 * 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)
{ … }

/**
 * 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)
{ … }

/**
 * 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)
{ … }

/**
 * 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)
{ … }

/**
 * 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)
{ … }

/**
 * 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)
{ … }

/**
 * 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)
{ … }

#ifdef CONFIG_PM_SLEEP
/**
 * virtsnd_freeze() - Suspend device.
 * @vdev: VirtIO parent device.
 *
 * Context: Any context.
 * Return: 0 on success, -errno on failure.
 */
static int virtsnd_freeze(struct virtio_device *vdev)
{ … }

/**
 * virtsnd_restore() - Resume device.
 * @vdev: VirtIO parent device.
 *
 * Context: Any context.
 * Return: 0 on success, -errno on failure.
 */
static int virtsnd_restore(struct virtio_device *vdev)
{ … }
#endif /* CONFIG_PM_SLEEP */

static const struct virtio_device_id id_table[] = …;

static unsigned int features[] = …;

static struct virtio_driver virtsnd_driver = …;

module_virtio_driver(…) …;

MODULE_DEVICE_TABLE(virtio, id_table);
MODULE_DESCRIPTION(…) …;
MODULE_LICENSE(…) …;