virtio_pcm.h

  1/* SPDX-License-Identifier: GPL-2.0+ */
  2/*
  3 * virtio-snd: Virtio sound device
  4 * Copyright (C) 2021 OpenSynergy GmbH
  5 */
  6#ifndef VIRTIO_SND_PCM_H
  7#define VIRTIO_SND_PCM_H
  8
  9#include <linux/atomic.h>
 10#include <linux/virtio_config.h>
 11#include <sound/pcm.h>
 12#include <sound/pcm-indirect.h>
 13
 14struct virtio_pcm;
 15struct virtio_pcm_msg;
 16
 17/**
 18 * struct virtio_pcm_substream - VirtIO PCM substream.
 19 * @snd: VirtIO sound device.
 20 * @nid: Function group node identifier.
 21 * @sid: Stream identifier.
 22 * @direction: Stream data flow direction (SNDRV_PCM_STREAM_XXX).
 23 * @features: Stream VirtIO feature bit map (1 << VIRTIO_SND_PCM_F_XXX).
 24 * @substream: Kernel ALSA substream.
 25 * @pcm_indirect: Kernel indirect pcm structure.
 26 * @hw: Kernel ALSA substream hardware descriptor.
 27 * @elapsed_period: Kernel work to handle the elapsed period state.
 28 * @lock: Spinlock that protects fields shared by interrupt handlers and
 29 *        substream operators.
 30 * @buffer_bytes: Current buffer size in bytes.
 31 * @hw_ptr: Substream hardware pointer value in bytes [0 ... buffer_bytes).
 32 * @xfer_enabled: Data transfer state (0 - off, 1 - on).
 33 * @xfer_xrun: Data underflow/overflow state (0 - no xrun, 1 - xrun).
 34 * @stopped: True if the substream is stopped and must be released on the device
 35 *           side.
 36 * @suspended: True if the substream is suspended and must be reconfigured on
 37 *             the device side at resume.
 38 * @msgs: Allocated I/O messages.
 39 * @nmsgs: Number of allocated I/O messages.
 40 * @msg_last_enqueued: Index of the last I/O message added to the virtqueue.
 41 * @msg_count: Number of pending I/O messages in the virtqueue.
 42 * @msg_empty: Notify when msg_count is zero.
 43 */
 44struct virtio_pcm_substream {
 45	struct virtio_snd *snd;
 46	u32 nid;
 47	u32 sid;
 48	u32 direction;
 49	u32 features;
 50	struct snd_pcm_substream *substream;
 51	struct snd_pcm_indirect pcm_indirect;
 52	struct snd_pcm_hardware hw;
 53	struct work_struct elapsed_period;
 54	spinlock_t lock;
 55	size_t buffer_bytes;
 56	size_t hw_ptr;
 57	bool xfer_enabled;
 58	bool xfer_xrun;
 59	bool stopped;
 60	bool suspended;
 61	struct virtio_pcm_msg **msgs;
 62	unsigned int nmsgs;
 63	unsigned int msg_count;
 64	wait_queue_head_t msg_empty;
 65};
 66
 67/**
 68 * struct virtio_pcm_stream - VirtIO PCM stream.
 69 * @substreams: VirtIO substreams belonging to the stream.
 70 * @nsubstreams: Number of substreams.
 71 * @chmaps: Kernel channel maps belonging to the stream.
 72 * @nchmaps: Number of channel maps.
 73 */
 74struct virtio_pcm_stream {
 75	struct virtio_pcm_substream **substreams;
 76	u32 nsubstreams;
 77	struct snd_pcm_chmap_elem *chmaps;
 78	u32 nchmaps;
 79};
 80
 81/**
 82 * struct virtio_pcm - VirtIO PCM device.
 83 * @list: VirtIO PCM list entry.
 84 * @nid: Function group node identifier.
 85 * @pcm: Kernel PCM device.
 86 * @streams: VirtIO PCM streams (playback and capture).
 87 */
 88struct virtio_pcm {
 89	struct list_head list;
 90	u32 nid;
 91	struct snd_pcm *pcm;
 92	struct virtio_pcm_stream streams[SNDRV_PCM_STREAM_LAST + 1];
 93};
 94
 95extern const struct snd_pcm_ops virtsnd_pcm_ops[];
 96
 97int virtsnd_pcm_validate(struct virtio_device *vdev);
 98
 99int virtsnd_pcm_parse_cfg(struct virtio_snd *snd);
100
101int virtsnd_pcm_build_devs(struct virtio_snd *snd);
102
103void virtsnd_pcm_event(struct virtio_snd *snd, struct virtio_snd_event *event);
104
105void virtsnd_pcm_tx_notify_cb(struct virtqueue *vqueue);
106
107void virtsnd_pcm_rx_notify_cb(struct virtqueue *vqueue);
108
109struct virtio_pcm *virtsnd_pcm_find(struct virtio_snd *snd, u32 nid);
110
111struct virtio_pcm *virtsnd_pcm_find_or_create(struct virtio_snd *snd, u32 nid);
112
113struct virtio_snd_msg *
114virtsnd_pcm_ctl_msg_alloc(struct virtio_pcm_substream *vss,
115			  unsigned int command, gfp_t gfp);
116
117int virtsnd_pcm_msg_alloc(struct virtio_pcm_substream *vss,
118			  unsigned int periods, unsigned int period_bytes);
119
120void virtsnd_pcm_msg_free(struct virtio_pcm_substream *vss);
121
122int virtsnd_pcm_msg_send(struct virtio_pcm_substream *vss, unsigned long offset,
123			 unsigned long bytes);
124
125unsigned int virtsnd_pcm_msg_pending_num(struct virtio_pcm_substream *vss);
126
127#endif /* VIRTIO_SND_PCM_H */