dma.h

linux-2.4.29操作系统的源码

/*
 * Definitions shared between dma-sa1100.c and dma-sa1111.c
 * (C) 2000 Nicolas Pitre <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/config.h>

/*
 * DMA buffer structure
 */

typedef struct dma_buf_s {
	int size;		/* buffer size */
	dma_addr_t dma_start;	/* starting DMA address */
	dma_addr_t dma_ptr;	/* next DMA pointer to use */
	int ref;		/* number of DMA references */
	void *id;		/* to identify buffer from outside */
	struct dma_buf_s *next;	/* next buffer to process */
} dma_buf_t;


/*
 * DMA channel structure.
 */

typedef struct {
	unsigned int in_use;	/* Device is allocated */
	const char *device_id;	/* Device name */
	dma_device_t device;	/* ... to which this channel is attached */
	dma_buf_t *head;	/* where to insert buffers */
	dma_buf_t *tail;	/* where to remove buffers */
	dma_buf_t *curr;	/* buffer currently DMA'ed */
	int stopped;		/* 1 if DMA is stalled */
	dma_regs_t *regs;	/* points to appropriate DMA registers */
	int irq;		/* IRQ used by the channel */
	dma_callback_t callback; /* ... to call when buffers are done */
	int spin_size;		/* > 0 when DMA should spin when no more buffer */
	dma_addr_t spin_addr;	/* DMA address to spin onto */
	int spin_ref;		/* number of spinning references */
#ifdef CONFIG_SA1111
	int dma_a, dma_b, last_dma; /* SA-1111 specific */
#endif
} sa1100_dma_t;

extern sa1100_dma_t dma_chan[MAX_SA1100_DMA_CHANNELS];


int start_sa1111_sac_dma(sa1100_dma_t *dma, dma_addr_t dma_ptr, size_t size);
int sa1111_dma_get_current(dmach_t channel, void **buf_id, dma_addr_t *addr);
int sa1111_dma_stop(dmach_t channel);
int sa1111_dma_resume(dmach_t channel);
void sa1111_reset_sac_dma(dmach_t channel);
void sa1111_cleanup_sac_dma(dmach_t channel);

void sa1100_dma_done (sa1100_dma_t *dma);


#ifdef CONFIG_SA1111
#define channel_is_sa1111_sac(ch) \
	((ch) >= SA1111_SAC_DMA_BASE && \
	 (ch) <  SA1111_SAC_DMA_BASE + SA1111_SAC_DMA_CHANNELS)
#else
#define channel_is_sa1111_sac(ch) (0)
#endif