linux/drivers/slimbus/stream.c

// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2018, Linaro Limited

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/slimbus.h>
#include <uapi/sound/asound.h>
#include "slimbus.h"

/**
 * struct segdist_code - Segment Distributions code from
 *	Table 20 of SLIMbus Specs Version 2.0
 *
 * @ratem: Channel Rate Multipler(Segments per Superframe)
 * @seg_interval: Number of slots between the first Slot of Segment
 *		and the first slot of the next  consecutive Segment.
 * @segdist_code: Segment Distribution Code SD[11:0]
 * @seg_offset_mask: Segment offset mask in SD[11:0]
 */
struct segdist_code { … };

/* segdist_codes - List of all possible Segment Distribution codes. */
static const struct segdist_code segdist_codes[] = …;

/*
 * Presence Rate table for all Natural Frequencies
 * The Presence rate of a constant bitrate stream is mean flow rate of the
 * stream expressed in occupied Segments of that Data Channel per second.
 * Table 66 from SLIMbus 2.0 Specs
 *
 * Index of the table corresponds to Presence rate code for the respective rate
 * in the table.
 */
static const int slim_presence_rate_table[] = …;

/**
 * slim_stream_allocate() - Allocate a new SLIMbus Stream
 * @dev:Slim device to be associated with
 * @name: name of the stream
 *
 * This is very first call for SLIMbus streaming, this API will allocate
 * a new SLIMbus stream and return a valid stream runtime pointer for client
 * to use it in subsequent stream apis. state of stream is set to ALLOCATED
 *
 * Return: valid pointer on success and error code on failure.
 * From ASoC DPCM framework, this state is linked to startup() operation.
 */
struct slim_stream_runtime *slim_stream_allocate(struct slim_device *dev,
						 const char *name)
{ … }
EXPORT_SYMBOL_GPL(…);

static int slim_connect_port_channel(struct slim_stream_runtime *stream,
				     struct slim_port *port)
{ … }

static int slim_disconnect_port(struct slim_stream_runtime *stream,
				struct slim_port *port)
{ … }

static int slim_deactivate_remove_channel(struct slim_stream_runtime *stream,
					  struct slim_port *port)
{ … }

static int slim_get_prate_code(int rate)
{ … }

/**
 * slim_stream_prepare() - Prepare a SLIMbus Stream
 *
 * @rt: instance of slim stream runtime to configure
 * @cfg: new configuration for the stream
 *
 * This API will configure SLIMbus stream with config parameters from cfg.
 * return zero on success and error code on failure. From ASoC DPCM framework,
 * this state is linked to hw_params() operation.
 */
int slim_stream_prepare(struct slim_stream_runtime *rt,
			struct slim_stream_config *cfg)
{ … }
EXPORT_SYMBOL_GPL(…);

static int slim_define_channel_content(struct slim_stream_runtime *stream,
				       struct slim_port *port)
{ … }

static int slim_get_segdist_code(int ratem)
{ … }

static int slim_define_channel(struct slim_stream_runtime *stream,
				       struct slim_port *port)
{ … }

static int slim_activate_channel(struct slim_stream_runtime *stream,
				 struct slim_port *port)
{ … }

/**
 * slim_stream_enable() - Enable a prepared SLIMbus Stream
 *
 * @stream: instance of slim stream runtime to enable
 *
 * This API will enable all the ports and channels associated with
 * SLIMbus stream
 *
 * Return: zero on success and error code on failure. From ASoC DPCM framework,
 * this state is linked to trigger() start operation.
 */
int slim_stream_enable(struct slim_stream_runtime *stream)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * slim_stream_disable() - Disable a SLIMbus Stream
 *
 * @stream: instance of slim stream runtime to disable
 *
 * This API will disable all the ports and channels associated with
 * SLIMbus stream
 *
 * Return: zero on success and error code on failure. From ASoC DPCM framework,
 * this state is linked to trigger() pause operation.
 */
int slim_stream_disable(struct slim_stream_runtime *stream)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * slim_stream_unprepare() - Un-prepare a SLIMbus Stream
 *
 * @stream: instance of slim stream runtime to unprepare
 *
 * This API will un allocate all the ports and channels associated with
 * SLIMbus stream
 *
 * Return: zero on success and error code on failure. From ASoC DPCM framework,
 * this state is linked to trigger() stop operation.
 */
int slim_stream_unprepare(struct slim_stream_runtime *stream)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * slim_stream_free() - Free a SLIMbus Stream
 *
 * @stream: instance of slim stream runtime to free
 *
 * This API will un allocate all the memory associated with
 * slim stream runtime, user is not allowed to make an dereference
 * to stream after this call.
 *
 * Return: zero on success and error code on failure. From ASoC DPCM framework,
 * this state is linked to shutdown() operation.
 */
int slim_stream_free(struct slim_stream_runtime *stream)
{ … }
EXPORT_SYMBOL_GPL(…);