at91_audio.h

来自「H9200F(2.6.12)的音频接口驱动。 操作方法： 1、将驱动程」· C头文件 代码 · 共 57 行

/*----------------------------------------------------------
**	linux/drivers/at91/at91_audio.h
**		
**
**	Copyright (C) 2006 Hyesco Technology Co.,Ltd
**
**	Author: casiawu <[e-mail]>
**
**	History:
**
**	2006.4   casiawu  <[e-mail]>
**               Original version
**---------------------------------------------------------*/

#ifndef __AT91_AUDIO_H_
#define __AT91_AUDIO_H_

#include "at91_pdc.h"

#define OUT_CHAN    0                /* write channel */
#define IN_CHAN     1                /* read  channel */

#define FILE_SAMPLING_FREQ	44100    // in Hz

/*
 * Buffer Management
 */

typedef struct {
	int size;		                       /* buffer size */
	char *start;		                   /* points to actual buffer */
	dma_addr_t dma_addr;	             /* physical buffer address */
	struct semaphore sem;	             /* down before touching the buffer */
	int master;		                     /* owner for buffer allocation, contain size when true */
	struct audio_stream_s *stream;	             /* owning stream */
} audio_buf_t;


typedef struct audio_stream_s {
	audio_buf_t *buffers;	               /* pointer to audio buffer structures */
	audio_buf_t *buf;	                   /* current buffer used by read/write */
	u_int buf_idx;		                 /* index for the pointer above... */
	u_int fragsize;		                 /* fragment i.e. buffer size */
	u_int nbfrags;		                 /* nbr of fragments i.e. buffers */
	int active;		                     /* actually in progress */	
	at91rm9200_dma_t * dma;		         /* DMA struct pointer */
	wait_queue_head_t wq;	             /* for poll */	
} audio_stream_t;

/* DMA channel 0: write ; 1: read */
at91rm9200_dma_t dma_chan[2];
audio_stream_t output_stream, input_stream;
at91rm9200_dma_state_t audio_state ;


#endif // __AT91_AUDIO_H_