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linux/sound/virtio/virtio_card.h
Anton Yakovlev d6568e3de4 ALSA: virtio: add support for audio controls
Implementation of support for audio controls in accordance with the
extension of the virtio sound device specification [1] planned for
virtio-v1.3-cs01.

The device can announce the VIRTIO_SND_F_CTLS feature. If the feature is
negotiated, then an additional field appears in the configuration space:

  struct virtio_snd_config {
    ...
    /* number of available control elements */
    __le32 controls;
  };

The driver can send the following requests to manage audio controls:

  enum {
    ...
    /* control element request types */
    VIRTIO_SND_R_CTL_INFO = 0x0300,
    VIRTIO_SND_R_CTL_ENUM_ITEMS,
    VIRTIO_SND_R_CTL_READ,
    VIRTIO_SND_R_CTL_WRITE,
    VIRTIO_SND_R_CTL_TLV_READ,
    VIRTIO_SND_R_CTL_TLV_WRITE,
    VIRTIO_SND_R_CTL_TLV_COMMAND,
    ...
  };

And the device can send the following audio control event notification:

  enum {
    ...
    /* control element event types */
    VIRTIO_SND_EVT_CTL_NOTIFY = 0x1200,
    ...
  };

See additional details in [1].

[1] https://lists.oasis-open.org/archives/virtio-comment/202104/msg00013.html

Signed-off-by: Anton Yakovlev <anton.yakovlev@opensynergy.com>
Signed-off-by: Aiswarya Cyriac <aiswarya.cyriac@opensynergy.com>
Link: https://lore.kernel.org/r/20240115133654.576068-2-aiswarya.cyriac@opensynergy.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2024-02-09 14:01:15 +01:00

134 lines
3.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0+ */
/*
* virtio-snd: Virtio sound device
* Copyright (C) 2021 OpenSynergy GmbH
*/
#ifndef VIRTIO_SND_CARD_H
#define VIRTIO_SND_CARD_H
#include <linux/slab.h>
#include <linux/virtio.h>
#include <sound/core.h>
#include <uapi/linux/virtio_snd.h>
#include "virtio_ctl_msg.h"
#include "virtio_pcm.h"
#define VIRTIO_SND_CARD_DRIVER "virtio-snd"
#define VIRTIO_SND_CARD_NAME "VirtIO SoundCard"
#define VIRTIO_SND_PCM_NAME "VirtIO PCM"
struct virtio_jack;
struct virtio_pcm_substream;
/**
* struct virtio_snd_queue - Virtqueue wrapper structure.
* @lock: Used to synchronize access to a virtqueue.
* @vqueue: Underlying virtqueue.
*/
struct virtio_snd_queue {
spinlock_t lock;
struct virtqueue *vqueue;
};
/**
* struct virtio_kctl - VirtIO control element.
* @kctl: ALSA control element.
* @items: Items for the ENUMERATED element type.
*/
struct virtio_kctl {
struct snd_kcontrol *kctl;
struct virtio_snd_ctl_enum_item *items;
};
/**
* struct virtio_snd - VirtIO sound card device.
* @vdev: Underlying virtio device.
* @queues: Virtqueue wrappers.
* @card: ALSA sound card.
* @ctl_msgs: Pending control request list.
* @event_msgs: Device events.
* @pcm_list: VirtIO PCM device list.
* @jacks: VirtIO jacks.
* @njacks: Number of jacks.
* @substreams: VirtIO PCM substreams.
* @nsubstreams: Number of PCM substreams.
* @chmaps: VirtIO channel maps.
* @nchmaps: Number of channel maps.
* @kctl_infos: VirtIO control element information.
* @kctls: VirtIO control elements.
* @nkctls: Number of control elements.
*/
struct virtio_snd {
struct virtio_device *vdev;
struct virtio_snd_queue queues[VIRTIO_SND_VQ_MAX];
struct snd_card *card;
struct list_head ctl_msgs;
struct virtio_snd_event *event_msgs;
struct list_head pcm_list;
struct virtio_jack *jacks;
u32 njacks;
struct virtio_pcm_substream *substreams;
u32 nsubstreams;
struct virtio_snd_chmap_info *chmaps;
u32 nchmaps;
struct virtio_snd_ctl_info *kctl_infos;
struct virtio_kctl *kctls;
u32 nkctls;
};
/* Message completion timeout in milliseconds (module parameter). */
extern u32 virtsnd_msg_timeout_ms;
static inline struct virtio_snd_queue *
virtsnd_control_queue(struct virtio_snd *snd)
{
return &snd->queues[VIRTIO_SND_VQ_CONTROL];
}
static inline struct virtio_snd_queue *
virtsnd_event_queue(struct virtio_snd *snd)
{
return &snd->queues[VIRTIO_SND_VQ_EVENT];
}
static inline struct virtio_snd_queue *
virtsnd_tx_queue(struct virtio_snd *snd)
{
return &snd->queues[VIRTIO_SND_VQ_TX];
}
static inline struct virtio_snd_queue *
virtsnd_rx_queue(struct virtio_snd *snd)
{
return &snd->queues[VIRTIO_SND_VQ_RX];
}
static inline struct virtio_snd_queue *
virtsnd_pcm_queue(struct virtio_pcm_substream *vss)
{
if (vss->direction == SNDRV_PCM_STREAM_PLAYBACK)
return virtsnd_tx_queue(vss->snd);
else
return virtsnd_rx_queue(vss->snd);
}
int virtsnd_jack_parse_cfg(struct virtio_snd *snd);
int virtsnd_jack_build_devs(struct virtio_snd *snd);
void virtsnd_jack_event(struct virtio_snd *snd,
struct virtio_snd_event *event);
int virtsnd_chmap_parse_cfg(struct virtio_snd *snd);
int virtsnd_chmap_build_devs(struct virtio_snd *snd);
int virtsnd_kctl_parse_cfg(struct virtio_snd *snd);
int virtsnd_kctl_build_devs(struct virtio_snd *snd);
void virtsnd_kctl_event(struct virtio_snd *snd, struct virtio_snd_event *event);
#endif /* VIRTIO_SND_CARD_H */