pcm.h

linux 内核源代码

static inline snd_pcm_sframes_t snd_pcm_playback_hw_avail(struct snd_pcm_runtime *runtime)
{
	return runtime->buffer_size - snd_pcm_playback_avail(runtime);
}

static inline snd_pcm_sframes_t snd_pcm_capture_hw_avail(struct snd_pcm_runtime *runtime)
{
	return runtime->buffer_size - snd_pcm_capture_avail(runtime);
}

/**
 * snd_pcm_playback_ready - check whether the playback buffer is available
 * @substream: the pcm substream instance
 *
 * Checks whether enough free space is available on the playback buffer.
 *
 * Returns non-zero if available, or zero if not.
 */
static inline int snd_pcm_playback_ready(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	return snd_pcm_playback_avail(runtime) >= runtime->control->avail_min;
}

/**
 * snd_pcm_capture_ready - check whether the capture buffer is available
 * @substream: the pcm substream instance
 *
 * Checks whether enough capture data is available on the capture buffer.
 *
 * Returns non-zero if available, or zero if not.
 */
static inline int snd_pcm_capture_ready(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	return snd_pcm_capture_avail(runtime) >= runtime->control->avail_min;
}

/**
 * snd_pcm_playback_data - check whether any data exists on the playback buffer
 * @substream: the pcm substream instance
 *
 * Checks whether any data exists on the playback buffer. If stop_threshold
 * is bigger or equal to boundary, then this function returns always non-zero.
 *
 * Returns non-zero if exists, or zero if not.
 */
static inline int snd_pcm_playback_data(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	
	if (runtime->stop_threshold >= runtime->boundary)
		return 1;
	return snd_pcm_playback_avail(runtime) < runtime->buffer_size;
}

/**
 * snd_pcm_playback_empty - check whether the playback buffer is empty
 * @substream: the pcm substream instance
 *
 * Checks whether the playback buffer is empty.
 *
 * Returns non-zero if empty, or zero if not.
 */
static inline int snd_pcm_playback_empty(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	return snd_pcm_playback_avail(runtime) >= runtime->buffer_size;
}

/**
 * snd_pcm_capture_empty - check whether the capture buffer is empty
 * @substream: the pcm substream instance
 *
 * Checks whether the capture buffer is empty.
 *
 * Returns non-zero if empty, or zero if not.
 */
static inline int snd_pcm_capture_empty(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	return snd_pcm_capture_avail(runtime) == 0;
}

static inline void snd_pcm_trigger_done(struct snd_pcm_substream *substream, 
					struct snd_pcm_substream *master)
{
	substream->runtime->trigger_master = master;
}

static inline int hw_is_mask(int var)
{
	return var >= SNDRV_PCM_HW_PARAM_FIRST_MASK &&
		var <= SNDRV_PCM_HW_PARAM_LAST_MASK;
}

static inline int hw_is_interval(int var)
{
	return var >= SNDRV_PCM_HW_PARAM_FIRST_INTERVAL &&
		var <= SNDRV_PCM_HW_PARAM_LAST_INTERVAL;
}

static inline struct snd_mask *hw_param_mask(struct snd_pcm_hw_params *params,
				     snd_pcm_hw_param_t var)
{
	return &params->masks[var - SNDRV_PCM_HW_PARAM_FIRST_MASK];
}

static inline struct snd_interval *hw_param_interval(struct snd_pcm_hw_params *params,
					     snd_pcm_hw_param_t var)
{
	return &params->intervals[var - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL];
}

static inline const struct snd_mask *hw_param_mask_c(const struct snd_pcm_hw_params *params,
					     snd_pcm_hw_param_t var)
{
	return &params->masks[var - SNDRV_PCM_HW_PARAM_FIRST_MASK];
}

static inline const struct snd_interval *hw_param_interval_c(const struct snd_pcm_hw_params *params,
						     snd_pcm_hw_param_t var)
{
	return &params->intervals[var - SNDRV_PCM_HW_PARAM_FIRST_INTERVAL];
}

#define params_access(p) snd_mask_min(hw_param_mask((p), SNDRV_PCM_HW_PARAM_ACCESS))
#define params_format(p) snd_mask_min(hw_param_mask((p), SNDRV_PCM_HW_PARAM_FORMAT))
#define params_subformat(p) snd_mask_min(hw_param_mask((p), SNDRV_PCM_HW_PARAM_SUBFORMAT))
#define params_channels(p) hw_param_interval((p), SNDRV_PCM_HW_PARAM_CHANNELS)->min
#define params_rate(p) hw_param_interval((p), SNDRV_PCM_HW_PARAM_RATE)->min
#define params_period_size(p) hw_param_interval((p), SNDRV_PCM_HW_PARAM_PERIOD_SIZE)->min
#define params_period_bytes(p) ((params_period_size(p)*snd_pcm_format_physical_width(params_format(p))*params_channels(p))/8)
#define params_periods(p) hw_param_interval((p), SNDRV_PCM_HW_PARAM_PERIODS)->min
#define params_buffer_size(p) hw_param_interval((p), SNDRV_PCM_HW_PARAM_BUFFER_SIZE)->min
#define params_buffer_bytes(p) hw_param_interval((p), SNDRV_PCM_HW_PARAM_BUFFER_BYTES)->min
#define params_tick_time(p) hw_param_interval((p), SNDRV_PCM_HW_PARAM_TICK_TIME)->min


int snd_interval_refine(struct snd_interval *i, const struct snd_interval *v);
void snd_interval_mul(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c);
void snd_interval_div(const struct snd_interval *a, const struct snd_interval *b, struct snd_interval *c);
void snd_interval_muldivk(const struct snd_interval *a, const struct snd_interval *b, 
			  unsigned int k, struct snd_interval *c);
void snd_interval_mulkdiv(const struct snd_interval *a, unsigned int k,
			  const struct snd_interval *b, struct snd_interval *c);
int snd_interval_list(struct snd_interval *i, unsigned int count, unsigned int *list, unsigned int mask);
int snd_interval_ratnum(struct snd_interval *i,
			unsigned int rats_count, struct snd_ratnum *rats,
			unsigned int *nump, unsigned int *denp);

void _snd_pcm_hw_params_any(struct snd_pcm_hw_params *params);
void _snd_pcm_hw_param_setempty(struct snd_pcm_hw_params *params, snd_pcm_hw_param_t var);
int snd_pcm_hw_params_choose(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params);

int snd_pcm_hw_refine(struct snd_pcm_substream *substream, struct snd_pcm_hw_params *params);

int snd_pcm_hw_constraints_init(struct snd_pcm_substream *substream);
int snd_pcm_hw_constraints_complete(struct snd_pcm_substream *substream);

int snd_pcm_hw_constraint_mask(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
			       u_int32_t mask);
int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
				 u_int64_t mask);
int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var,
				 unsigned int min, unsigned int max);
int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var);
int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime, 
			       unsigned int cond,
			       snd_pcm_hw_param_t var,
			       struct snd_pcm_hw_constraint_list *l);
int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime, 
				  unsigned int cond,
				  snd_pcm_hw_param_t var,
				  struct snd_pcm_hw_constraint_ratnums *r);
int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime, 
				  unsigned int cond,
				  snd_pcm_hw_param_t var,
				  struct snd_pcm_hw_constraint_ratdens *r);
int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime, 
				 unsigned int cond,
				 unsigned int width,
				 unsigned int msbits);
int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime,
			       unsigned int cond,
			       snd_pcm_hw_param_t var,
			       unsigned long step);
int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime,
			       unsigned int cond,
			       snd_pcm_hw_param_t var);
int snd_pcm_hw_rule_add(struct snd_pcm_runtime *runtime,
			unsigned int cond,
			int var,
			snd_pcm_hw_rule_func_t func, void *private,
			int dep, ...);

int snd_pcm_format_signed(snd_pcm_format_t format);
int snd_pcm_format_unsigned(snd_pcm_format_t format);
int snd_pcm_format_linear(snd_pcm_format_t format);
int snd_pcm_format_little_endian(snd_pcm_format_t format);
int snd_pcm_format_big_endian(snd_pcm_format_t format);
#if 0 /* just for DocBook */
/**
 * snd_pcm_format_cpu_endian - Check the PCM format is CPU-endian
 * @format: the format to check
 *
 * Returns 1 if the given PCM format is CPU-endian, 0 if
 * opposite, or a negative error code if endian not specified.
 */
int snd_pcm_format_cpu_endian(snd_pcm_format_t format);
#endif /* DocBook */
#ifdef SNDRV_LITTLE_ENDIAN
#define snd_pcm_format_cpu_endian(format) snd_pcm_format_little_endian(format)
#else
#define snd_pcm_format_cpu_endian(format) snd_pcm_format_big_endian(format)
#endif
int snd_pcm_format_width(snd_pcm_format_t format);			/* in bits */
int snd_pcm_format_physical_width(snd_pcm_format_t format);		/* in bits */
ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples);
const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format);
int snd_pcm_format_set_silence(snd_pcm_format_t format, void *buf, unsigned int frames);
snd_pcm_format_t snd_pcm_build_linear_format(int width, int unsignd, int big_endian);

void snd_pcm_set_ops(struct snd_pcm * pcm, int direction, struct snd_pcm_ops *ops);
void snd_pcm_set_sync(struct snd_pcm_substream *substream);
int snd_pcm_lib_interleave_len(struct snd_pcm_substream *substream);
int snd_pcm_lib_ioctl(struct snd_pcm_substream *substream,
		      unsigned int cmd, void *arg);                      
int snd_pcm_update_hw_ptr(struct snd_pcm_substream *substream);
int snd_pcm_playback_xrun_check(struct snd_pcm_substream *substream);
int snd_pcm_capture_xrun_check(struct snd_pcm_substream *substream);
int snd_pcm_playback_xrun_asap(struct snd_pcm_substream *substream);
int snd_pcm_capture_xrun_asap(struct snd_pcm_substream *substream);
void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_uframes_t new_hw_ptr);
void snd_pcm_tick_prepare(struct snd_pcm_substream *substream);
void snd_pcm_tick_set(struct snd_pcm_substream *substream, unsigned long ticks);
void snd_pcm_tick_elapsed(struct snd_pcm_substream *substream);
void snd_pcm_period_elapsed(struct snd_pcm_substream *substream);
snd_pcm_sframes_t snd_pcm_lib_write(struct snd_pcm_substream *substream,
				    const void __user *buf,
				    snd_pcm_uframes_t frames);
snd_pcm_sframes_t snd_pcm_lib_read(struct snd_pcm_substream *substream,
				   void __user *buf, snd_pcm_uframes_t frames);
snd_pcm_sframes_t snd_pcm_lib_writev(struct snd_pcm_substream *substream,
				     void __user **bufs, snd_pcm_uframes_t frames);
snd_pcm_sframes_t snd_pcm_lib_readv(struct snd_pcm_substream *substream,
				    void __user **bufs, snd_pcm_uframes_t frames);

extern const struct snd_pcm_hw_constraint_list snd_pcm_known_rates;

int snd_pcm_limit_hw_rates(struct snd_pcm_runtime *runtime);
unsigned int snd_pcm_rate_to_rate_bit(unsigned int rate);

static inline void snd_pcm_set_runtime_buffer(struct snd_pcm_substream *substream,
					      struct snd_dma_buffer *bufp)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	if (bufp) {
		runtime->dma_buffer_p = bufp;
		runtime->dma_area = bufp->area;
		runtime->dma_addr = bufp->addr;
		runtime->dma_bytes = bufp->bytes;
	} else {
		runtime->dma_buffer_p = NULL;
		runtime->dma_area = NULL;
		runtime->dma_addr = 0;
		runtime->dma_bytes = 0;
	}
}

/*
 *  Timer interface
 */

void snd_pcm_timer_resolution_change(struct snd_pcm_substream *substream);
void snd_pcm_timer_init(struct snd_pcm_substream *substream);
void snd_pcm_timer_done(struct snd_pcm_substream *substream);

/*
 *  Memory
 */

int snd_pcm_lib_preallocate_free(struct snd_pcm_substream *substream);
int snd_pcm_lib_preallocate_free_for_all(struct snd_pcm *pcm);
int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream *substream,
				  int type, struct device *data,
				  size_t size, size_t max);
int snd_pcm_lib_preallocate_pages_for_all(struct snd_pcm *pcm,
					  int type, void *data,
					  size_t size, size_t max);
int snd_pcm_lib_malloc_pages(struct snd_pcm_substream *substream, size_t size);
int snd_pcm_lib_free_pages(struct snd_pcm_substream *substream);

#define snd_pcm_substream_sgbuf(substream) ((substream)->runtime->dma_buffer_p->private_data)
#define snd_pcm_sgbuf_pages(size) snd_sgbuf_aligned_pages(size)
#define snd_pcm_sgbuf_get_addr(sgbuf,ofs) snd_sgbuf_get_addr(sgbuf,ofs)
struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, unsigned long offset);

/* handle mmap counter - PCM mmap callback should handle this counter properly */
static inline void snd_pcm_mmap_data_open(struct vm_area_struct *area)
{
	struct snd_pcm_substream *substream = (struct snd_pcm_substream *)area->vm_private_data;
	atomic_inc(&substream->mmap_count);
}

static inline void snd_pcm_mmap_data_close(struct vm_area_struct *area)
{
	struct snd_pcm_substream *substream = (struct snd_pcm_substream *)area->vm_private_data;
	atomic_dec(&substream->mmap_count);
}

/* mmap for io-memory area */
#if defined(CONFIG_X86) || defined(CONFIG_PPC) || defined(CONFIG_ALPHA)
#define SNDRV_PCM_INFO_MMAP_IOMEM	SNDRV_PCM_INFO_MMAP
int snd_pcm_lib_mmap_iomem(struct snd_pcm_substream *substream, struct vm_area_struct *area);
#else
#define SNDRV_PCM_INFO_MMAP_IOMEM	0
#define snd_pcm_lib_mmap_iomem	NULL
#endif

static inline void snd_pcm_limit_isa_dma_size(int dma, size_t *max)
{
	*max = dma < 4 ? 64 * 1024 : 128 * 1024;
}

/*
 *  Misc
 */

#define SNDRV_PCM_DEFAULT_CON_SPDIF	(IEC958_AES0_CON_EMPHASIS_NONE|\
					 (IEC958_AES1_CON_ORIGINAL<<8)|\
					 (IEC958_AES1_CON_PCM_CODER<<8)|\
					 (IEC958_AES3_CON_FS_48000<<24))

#endif /* __SOUND_PCM_H */