linux/sound/virtio/virtio_pcm.h

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/* 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.
* @elapsed_period: Kernel work to handle the elapsed period state.
* @lock: Spinlock that protects fields shared by interrupt handlers and
* substream operators.
* @buffer_bytes: Current buffer size in bytes.
* @hw_ptr: Substream hardware pointer value in bytes [0 ... buffer_bytes).
* @xfer_enabled: Data transfer state (0 - off, 1 - on).
* @xfer_xrun: Data underflow/overflow state (0 - no xrun, 1 - xrun).
* @stopped: True if the substream is stopped and must be released on the device
* side.
* @suspended: True if the substream is suspended and must be reconfigured on
* the device side at resume.
* @msgs: Allocated I/O messages.
* @nmsgs: Number of allocated I/O messages.
* @msg_last_enqueued: Index of the last I/O message added to the virtqueue.
* @msg_count: Number of pending I/O messages in the virtqueue.
* @msg_empty: Notify when msg_count is zero.
*/
struct virtio_pcm_substream {
struct virtio_snd *snd;
u32 nid;
u32 sid;
u32 direction;
u32 features;
struct snd_pcm_substream *substream;
struct snd_pcm_hardware hw;
struct work_struct elapsed_period;
spinlock_t lock;
size_t buffer_bytes;
size_t hw_ptr;
bool xfer_enabled;
bool xfer_xrun;
bool stopped;
bool suspended;
struct virtio_pcm_msg **msgs;
unsigned int nmsgs;
int msg_last_enqueued;
unsigned int msg_count;
wait_queue_head_t msg_empty;
};
/**
* struct virtio_pcm_stream - VirtIO PCM stream.
* @substreams: VirtIO substreams belonging to the stream.
* @nsubstreams: Number of substreams.
* @chmaps: Kernel channel maps belonging to the stream.
* @nchmaps: Number of channel maps.
*/
struct virtio_pcm_stream {
struct virtio_pcm_substream **substreams;
u32 nsubstreams;
struct snd_pcm_chmap_elem *chmaps;
u32 nchmaps;
};
/**
* 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;
u32 nid;
struct snd_pcm *pcm;
struct virtio_pcm_stream streams[SNDRV_PCM_STREAM_LAST + 1];
};
extern const struct snd_pcm_ops virtsnd_pcm_ops;
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);
void virtsnd_pcm_event(struct virtio_snd *snd, struct virtio_snd_event *event);
void virtsnd_pcm_tx_notify_cb(struct virtqueue *vqueue);
void virtsnd_pcm_rx_notify_cb(struct virtqueue *vqueue);
struct virtio_pcm *virtsnd_pcm_find(struct virtio_snd *snd, u32 nid);
struct virtio_pcm *virtsnd_pcm_find_or_create(struct virtio_snd *snd, u32 nid);
struct virtio_snd_msg *
virtsnd_pcm_ctl_msg_alloc(struct virtio_pcm_substream *vss,
unsigned int command, gfp_t gfp);
int virtsnd_pcm_msg_alloc(struct virtio_pcm_substream *vss,
unsigned int periods, unsigned int period_bytes);
void virtsnd_pcm_msg_free(struct virtio_pcm_substream *vss);
int virtsnd_pcm_msg_send(struct virtio_pcm_substream *vss);
unsigned int virtsnd_pcm_msg_pending_num(struct virtio_pcm_substream *vss);
#endif /* VIRTIO_SND_PCM_H */