linux/sound/core/pcm_iec958.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 *  PCM DRM helpers
 */
#include <linux/export.h>
#include <linux/types.h>
#include <sound/asoundef.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/pcm_iec958.h>

/**
 * snd_pcm_create_iec958_consumer_default - create default consumer format IEC958 channel status
 * @cs: channel status buffer, at least four bytes
 * @len: length of channel status buffer
 *
 * Create the consumer format channel status data in @cs of maximum size
 * @len. When relevant, the configuration-dependant bits will be set as
 * unspecified.
 *
 * Drivers should then call einter snd_pcm_fill_iec958_consumer() or
 * snd_pcm_fill_iec958_consumer_hw_params() to replace these unspecified
 * bits by their actual values.
 *
 * Drivers may wish to tweak the contents of the buffer after creation.
 *
 * Returns: length of buffer, or negative error code if something failed.
 */
int snd_pcm_create_iec958_consumer_default(u8 *cs, size_t len)
{ … }
EXPORT_SYMBOL_GPL(…);

static int fill_iec958_consumer(uint rate, uint sample_width,
				u8 *cs, size_t len)
{ … }

/**
 * snd_pcm_fill_iec958_consumer - Fill consumer format IEC958 channel status
 * @runtime: pcm runtime structure with ->rate filled in
 * @cs: channel status buffer, at least four bytes
 * @len: length of channel status buffer
 *
 * Fill the unspecified bits in an IEC958 status bits array using the
 * parameters of the PCM runtime @runtime.
 *
 * Drivers may wish to tweak the contents of the buffer after its been
 * filled.
 *
 * Returns: length of buffer, or negative error code if something failed.
 */
int snd_pcm_fill_iec958_consumer(struct snd_pcm_runtime *runtime,
				 u8 *cs, size_t len)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * snd_pcm_fill_iec958_consumer_hw_params - Fill consumer format IEC958 channel status
 * @params: the hw_params instance for extracting rate and sample format
 * @cs: channel status buffer, at least four bytes
 * @len: length of channel status buffer
 *
 * Fill the unspecified bits in an IEC958 status bits array using the
 * parameters of the PCM hardware parameters @params.
 *
 * Drivers may wish to tweak the contents of the buffer after its been
 * filled..
 *
 * Returns: length of buffer, or negative error code if something failed.
 */
int snd_pcm_fill_iec958_consumer_hw_params(struct snd_pcm_hw_params *params,
					   u8 *cs, size_t len)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * snd_pcm_create_iec958_consumer - create consumer format IEC958 channel status
 * @runtime: pcm runtime structure with ->rate filled in
 * @cs: channel status buffer, at least four bytes
 * @len: length of channel status buffer
 *
 * Create the consumer format channel status data in @cs of maximum size
 * @len corresponding to the parameters of the PCM runtime @runtime.
 *
 * Drivers may wish to tweak the contents of the buffer after creation.
 *
 * Returns: length of buffer, or negative error code if something failed.
 */
int snd_pcm_create_iec958_consumer(struct snd_pcm_runtime *runtime, u8 *cs,
	size_t len)
{ … }
EXPORT_SYMBOL(…);

/**
 * snd_pcm_create_iec958_consumer_hw_params - create IEC958 channel status
 * @params: the hw_params instance for extracting rate and sample format
 * @cs: channel status buffer, at least four bytes
 * @len: length of channel status buffer
 *
 * Create the consumer format channel status data in @cs of maximum size
 * @len corresponding to the parameters of the PCM runtime @runtime.
 *
 * Drivers may wish to tweak the contents of the buffer after creation.
 *
 * Returns: length of buffer, or negative error code if something failed.
 */
int snd_pcm_create_iec958_consumer_hw_params(struct snd_pcm_hw_params *params,
					     u8 *cs, size_t len)
{ … }
EXPORT_SYMBOL(…);