LXR linux/sound/virtio/virtio

   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 */
 125