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Release 4.12 include/sound/pcm-indirect.h

Directory: include/sound
/*
 * Helper functions for indirect PCM data transfer
 *
 *  Copyright (c) by Takashi Iwai <tiwai@suse.de>
 *                   Jaroslav Kysela <perex@perex.cz>
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#ifndef __SOUND_PCM_INDIRECT_H

#define __SOUND_PCM_INDIRECT_H

#include <sound/pcm.h>


struct snd_pcm_indirect {
	
unsigned int hw_buffer_size;	/* Byte size of hardware buffer */
	
unsigned int hw_queue_size;	/* Max queue size of hw buffer (0 = buffer size) */
	
unsigned int hw_data;	/* Offset to next dst (or src) in hw ring buffer */
	
unsigned int hw_io;	/* Ring buffer hw pointer */
	
int hw_ready;		/* Bytes ready for play (or captured) in hw ring buffer */
	
unsigned int sw_buffer_size;	/* Byte size of software buffer */
	
unsigned int sw_data;	/* Offset to next dst (or src) in sw ring buffer */
	
unsigned int sw_io;	/* Current software pointer in bytes */
	
int sw_ready;		/* Bytes ready to be transferred to/from hw */
	
snd_pcm_uframes_t appl_ptr;	/* Last seen appl_ptr */
};


typedef void (*snd_pcm_indirect_copy_t)(struct snd_pcm_substream *substream,
					struct snd_pcm_indirect *rec, size_t bytes);

/*
 * helper function for playback ack callback
 */

static inline void snd_pcm_indirect_playback_transfer(struct snd_pcm_substream *substream, struct snd_pcm_indirect *rec, snd_pcm_indirect_copy_t copy) { struct snd_pcm_runtime *runtime = substream->runtime; snd_pcm_uframes_t appl_ptr = runtime->control->appl_ptr; snd_pcm_sframes_t diff = appl_ptr - rec->appl_ptr; int qsize; if (diff) { if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2)) diff += runtime->boundary; rec->sw_ready += (int)frames_to_bytes(runtime, diff); rec->appl_ptr = appl_ptr; } qsize = rec->hw_queue_size ? rec->hw_queue_size : rec->hw_buffer_size; while (rec->hw_ready < qsize && rec->sw_ready > 0) { unsigned int hw_to_end = rec->hw_buffer_size - rec->hw_data; unsigned int sw_to_end = rec->sw_buffer_size - rec->sw_data; unsigned int bytes = qsize - rec->hw_ready; if (rec->sw_ready < (int)bytes) bytes = rec->sw_ready; if (hw_to_end < bytes) bytes = hw_to_end; if (sw_to_end < bytes) bytes = sw_to_end; if (! bytes) break; copy(substream, rec, bytes); rec->hw_data += bytes; if (rec->hw_data == rec->hw_buffer_size) rec->hw_data = 0; rec->sw_data += bytes; if (rec->sw_data == rec->sw_buffer_size) rec->sw_data = 0; rec->hw_ready += bytes; rec->sw_ready -= bytes; } }

Contributors

PersonTokensPropCommitsCommitProp
Jaroslav Kysela26497.78%266.67%
Takashi Iwai62.22%133.33%
Total270100.00%3100.00%

/* * helper function for playback pointer callback * ptr = current byte pointer */
static inline snd_pcm_uframes_t snd_pcm_indirect_playback_pointer(struct snd_pcm_substream *substream, struct snd_pcm_indirect *rec, unsigned int ptr) { int bytes = ptr - rec->hw_io; if (bytes < 0) bytes += rec->hw_buffer_size; rec->hw_io = ptr; rec->hw_ready -= bytes; rec->sw_io += bytes; if (rec->sw_io >= rec->sw_buffer_size) rec->sw_io -= rec->sw_buffer_size; if (substream->ops->ack) substream->ops->ack(substream); return bytes_to_frames(substream->runtime, rec->sw_io); }

Contributors

PersonTokensPropCommitsCommitProp
Jaroslav Kysela10396.26%266.67%
Takashi Iwai43.74%133.33%
Total107100.00%3100.00%

/* * helper function for capture ack callback */
static inline void snd_pcm_indirect_capture_transfer(struct snd_pcm_substream *substream, struct snd_pcm_indirect *rec, snd_pcm_indirect_copy_t copy) { struct snd_pcm_runtime *runtime = substream->runtime; snd_pcm_uframes_t appl_ptr = runtime->control->appl_ptr; snd_pcm_sframes_t diff = appl_ptr - rec->appl_ptr; if (diff) { if (diff < -(snd_pcm_sframes_t) (runtime->boundary / 2)) diff += runtime->boundary; rec->sw_ready -= frames_to_bytes(runtime, diff); rec->appl_ptr = appl_ptr; } while (rec->hw_ready > 0 && rec->sw_ready < (int)rec->sw_buffer_size) { size_t hw_to_end = rec->hw_buffer_size - rec->hw_data; size_t sw_to_end = rec->sw_buffer_size - rec->sw_data; size_t bytes = rec->sw_buffer_size - rec->sw_ready; if (rec->hw_ready < (int)bytes) bytes = rec->hw_ready; if (hw_to_end < bytes) bytes = hw_to_end; if (sw_to_end < bytes) bytes = sw_to_end; if (! bytes) break; copy(substream, rec, bytes); rec->hw_data += bytes; if ((int)rec->hw_data == rec->hw_buffer_size) rec->hw_data = 0; rec->sw_data += bytes; if (rec->sw_data == rec->sw_buffer_size) rec->sw_data = 0; rec->hw_ready -= bytes; rec->sw_ready += bytes; } }

Contributors

PersonTokensPropCommitsCommitProp
Jaroslav Kysela25197.67%150.00%
Takashi Iwai62.33%150.00%
Total257100.00%2100.00%

/* * helper function for capture pointer callback, * ptr = current byte pointer */
static inline snd_pcm_uframes_t snd_pcm_indirect_capture_pointer(struct snd_pcm_substream *substream, struct snd_pcm_indirect *rec, unsigned int ptr) { int qsize; int bytes = ptr - rec->hw_io; if (bytes < 0) bytes += rec->hw_buffer_size; rec->hw_io = ptr; rec->hw_ready += bytes; qsize = rec->hw_queue_size ? rec->hw_queue_size : rec->hw_buffer_size; if (rec->hw_ready > qsize) return SNDRV_PCM_POS_XRUN; rec->sw_io += bytes; if (rec->sw_io >= rec->sw_buffer_size) rec->sw_io -= rec->sw_buffer_size; if (substream->ops->ack) substream->ops->ack(substream); return bytes_to_frames(substream->runtime, rec->sw_io); }

Contributors

PersonTokensPropCommitsCommitProp
Jaroslav Kysela13197.04%375.00%
Takashi Iwai42.96%125.00%
Total135100.00%4100.00%

#endif /* __SOUND_PCM_INDIRECT_H */

Overall Contributors

PersonTokensPropCommitsCommitProp
Jaroslav Kysela83396.97%480.00%
Takashi Iwai263.03%120.00%
Total859100.00%5100.00%
Directory: include/sound
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