linux/include/sound/compress_driver.h

/* SPDX-License-Identifier: GPL-2.0
 *
 *  compress_driver.h - compress offload driver definations
 *
 *  Copyright (C) 2011 Intel Corporation
 *  Authors:	Vinod Koul <[email protected]>
 *		Pierre-Louis Bossart <[email protected]>
 */

#ifndef __COMPRESS_DRIVER_H
#define __COMPRESS_DRIVER_H

#include <linux/types.h>
#include <linux/sched.h>
#include <sound/core.h>
#include <sound/compress_offload.h>
#include <sound/asound.h>
#include <sound/pcm.h>

struct snd_compr_ops;

/**
 * struct snd_compr_runtime: runtime stream description
 * @state: stream state
 * @ops: pointer to DSP callbacks
 * @buffer: pointer to kernel buffer, valid only when not in mmap mode or
 *	DSP doesn't implement copy
 * @buffer_size: size of the above buffer
 * @fragment_size: size of buffer fragment in bytes
 * @fragments: number of such fragments
 * @total_bytes_available: cumulative number of bytes made available in
 *	the ring buffer
 * @total_bytes_transferred: cumulative bytes transferred by offload DSP
 * @sleep: poll sleep
 * @private_data: driver private data pointer
 * @dma_area: virtual buffer address
 * @dma_addr: physical buffer address (not accessible from main CPU)
 * @dma_bytes: size of DMA area
 * @dma_buffer_p: runtime dma buffer pointer
 */
struct snd_compr_runtime { … };

/**
 * struct snd_compr_stream: compressed stream
 * @name: device name
 * @ops: pointer to DSP callbacks
 * @runtime: pointer to runtime structure
 * @device: device pointer
 * @error_work: delayed work used when closing the stream due to an error
 * @direction: stream direction, playback/recording
 * @metadata_set: metadata set flag, true when set
 * @next_track: has userspace signal next track transition, true when set
 * @partial_drain: undergoing partial_drain for stream, true when set
 * @pause_in_draining: paused during draining state, true when set
 * @private_data: pointer to DSP private data
 * @dma_buffer: allocated buffer if any
 */
struct snd_compr_stream { … };

/**
 * struct snd_compr_ops: compressed path DSP operations
 * @open: Open the compressed stream
 * This callback is mandatory and shall keep dsp ready to receive the stream
 * parameter
 * @free: Close the compressed stream, mandatory
 * @set_params: Sets the compressed stream parameters, mandatory
 * This can be called in during stream creation only to set codec params
 * and the stream properties
 * @get_params: retrieve the codec parameters, mandatory
 * @set_metadata: Set the metadata values for a stream
 * @get_metadata: retrieves the requested metadata values from stream
 * @trigger: Trigger operations like start, pause, resume, drain, stop.
 * This callback is mandatory
 * @pointer: Retrieve current h/w pointer information. Mandatory
 * @copy: Copy the compressed data to/from userspace, Optional
 * Can't be implemented if DSP supports mmap
 * @mmap: DSP mmap method to mmap DSP memory
 * @ack: Ack for DSP when data is written to audio buffer, Optional
 * Not valid if copy is implemented
 * @get_caps: Retrieve DSP capabilities, mandatory
 * @get_codec_caps: Retrieve capabilities for a specific codec, mandatory
 */
struct snd_compr_ops { … };

/**
 * struct snd_compr: Compressed device
 * @name: DSP device name
 * @dev: associated device instance
 * @ops: pointer to DSP callbacks
 * @private_data: pointer to DSP pvt data
 * @card: sound card pointer
 * @direction: Playback or capture direction
 * @lock: device lock
 * @device: device id
 * @use_pause_in_draining: allow pause in draining, true when set
 */
struct snd_compr { … };

/* compress device register APIs */
int snd_compress_new(struct snd_card *card, int device,
			int type, const char *id, struct snd_compr *compr);

/**
 * snd_compr_use_pause_in_draining - Allow pause and resume in draining state
 * @substream: compress substream to set
 *
 * Allow pause and resume in draining state.
 * Only HW driver supports this transition can call this API.
 */
static inline void snd_compr_use_pause_in_draining(struct snd_compr_stream *substream)
{ … }

/* dsp driver callback apis
 * For playback: driver should call snd_compress_fragment_elapsed() to let the
 * framework know that a fragment has been consumed from the ring buffer
 *
 * For recording: we want to know when a frame is available or when
 * at least one frame is available so snd_compress_frame_elapsed()
 * callback should be called when a encodeded frame is available
 */
static inline void snd_compr_fragment_elapsed(struct snd_compr_stream *stream)
{ … }

static inline void snd_compr_drain_notify(struct snd_compr_stream *stream)
{ … }

/**
 * snd_compr_set_runtime_buffer - Set the Compress runtime buffer
 * @stream: compress stream to set
 * @bufp: the buffer information, NULL to clear
 *
 * Copy the buffer information to runtime buffer when @bufp is non-NULL.
 * Otherwise it clears the current buffer information.
 */
static inline void
snd_compr_set_runtime_buffer(struct snd_compr_stream *stream,
			     struct snd_dma_buffer *bufp)
{ … }

int snd_compr_malloc_pages(struct snd_compr_stream *stream, size_t size);
int snd_compr_free_pages(struct snd_compr_stream *stream);

int snd_compr_stop_error(struct snd_compr_stream *stream,
			 snd_pcm_state_t state);

#endif