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