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-rw-r--r--sound/virtio/virtio_pcm.h124
1 files changed, 124 insertions, 0 deletions
diff --git a/sound/virtio/virtio_pcm.h b/sound/virtio/virtio_pcm.h
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+++ b/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 */