1. 根目录:
2. arch
3. arm
4. plat-pxa
5. include
6. plat
7. dma.h

#ifndef __PLAT_DMA_H
#define __PLAT_DMA_H

#define DMAC_REG(x)	(*((volatile u32 *)(DMAC_REGS_VIRT + (x))))

#define DCSR(n)		DMAC_REG((n) << 2)
#define DALGN		DMAC_REG(0x00a0)  /* DMA Alignment Register */
#define DINT		DMAC_REG(0x00f0)  /* DMA Interrupt Register */
#define DDADR(n)	DMAC_REG(0x0200 + ((n) << 4))
#define DSADR(n)	DMAC_REG(0x0204 + ((n) << 4))
#define DTADR(n)	DMAC_REG(0x0208 + ((n) << 4))
#define DCMD(n)		DMAC_REG(0x020c + ((n) << 4))
#define DRCMR(n)	DMAC_REG((((n) < 64) ? 0x0100 : 0x1100) + \
				 (((n) & 0x3f) << 2))

#define DCSR_RUN	(1 << 31)	/* Run Bit (read / write) */
#define DCSR_NODESC	(1 << 30)	/* No-Descriptor Fetch (read / write) */
#define DCSR_STOPIRQEN	(1 << 29)	/* Stop Interrupt Enable (read / write) */
#define DCSR_REQPEND	(1 << 8)	/* Request Pending (read-only) */
#define DCSR_STOPSTATE	(1 << 3)	/* Stop State (read-only) */
#define DCSR_ENDINTR	(1 << 2)	/* End Interrupt (read / write) */
#define DCSR_STARTINTR	(1 << 1)	/* Start Interrupt (read / write) */
#define DCSR_BUSERR	(1 << 0)	/* Bus Error Interrupt (read / write) */

#define DCSR_EORIRQEN	(1 << 28)       /* End of Receive Interrupt Enable (R/W) */
#define DCSR_EORJMPEN	(1 << 27)       /* Jump to next descriptor on EOR */
#define DCSR_EORSTOPEN	(1 << 26)       /* STOP on an EOR */
#define DCSR_SETCMPST	(1 << 25)       /* Set Descriptor Compare Status */
#define DCSR_CLRCMPST	(1 << 24)       /* Clear Descriptor Compare Status */
#define DCSR_CMPST	(1 << 10)       /* The Descriptor Compare Status */
#define DCSR_EORINTR	(1 << 9)        /* The end of Receive */

#define DRCMR_MAPVLD	(1 << 7)	/* Map Valid (read / write) */
#define DRCMR_CHLNUM	0x1f		/* mask for Channel Number (read / write) */

#define DDADR_DESCADDR	0xfffffff0	/* Address of next descriptor (mask) */
#define DDADR_STOP	(1 << 0)	/* Stop (read / write) */

#define DCMD_INCSRCADDR	(1 << 31)	/* Source Address Increment Setting. */
#define DCMD_INCTRGADDR	(1 << 30)	/* Target Address Increment Setting. */
#define DCMD_FLOWSRC	(1 << 29)	/* Flow Control by the source. */
#define DCMD_FLOWTRG	(1 << 28)	/* Flow Control by the target. */
#define DCMD_STARTIRQEN	(1 << 22)	/* Start Interrupt Enable */
#define DCMD_ENDIRQEN	(1 << 21)	/* End Interrupt Enable */
#define DCMD_ENDIAN	(1 << 18)	/* Device Endian-ness. */
#define DCMD_BURST8	(1 << 16)	/* 8 byte burst */
#define DCMD_BURST16	(2 << 16)	/* 16 byte burst */
#define DCMD_BURST32	(3 << 16)	/* 32 byte burst */
#define DCMD_WIDTH1	(1 << 14)	/* 1 byte width */
#define DCMD_WIDTH2	(2 << 14)	/* 2 byte width (HalfWord) */
#define DCMD_WIDTH4	(3 << 14)	/* 4 byte width (Word) */
#define DCMD_LENGTH	0x01fff		/* length mask (max = 8K - 1) */

/*
 * Descriptor structure for PXA's DMA engine
 * Note: this structure must always be aligned to a 16-byte boundary.
 */

typedef struct pxa_dma_desc {
	volatile u32 ddadr;	/* Points to the next descriptor + flags */
	volatile u32 dsadr;	/* DSADR value for the current transfer */
	volatile u32 dtadr;	/* DTADR value for the current transfer */
	volatile u32 dcmd;	/* DCMD value for the current transfer */
} pxa_dma_desc;

typedef enum {
	DMA_PRIO_HIGH = 0,
	DMA_PRIO_MEDIUM = 1,
	DMA_PRIO_LOW = 2
} pxa_dma_prio;

/*
 * DMA registration
 */

int __init pxa_init_dma(int irq, int num_ch);

int pxa_request_dma (char *name,
			 pxa_dma_prio prio,
			 void (*irq_handler)(int, void *),
			 void *data);

void pxa_free_dma (int dma_ch);

#endif /* __PLAT_DMA_H */