/* SPDX-License-Identifier: GPL-2.0-only */
/*
 *  arch/arm/include/asm/mach/dma.h
 *
 *  Copyright (C) 1998-2000 Russell King
 *
 *  This header file describes the interface between the generic DMA handler
 *  (dma.c) and the architecture-specific DMA backends (dma-*.c)
 */

struct dma_struct;
typedef struct dma_struct dma_t;

struct dma_ops {
        int     (*request)(unsigned int, dma_t *);              /* optional */
        void    (*free)(unsigned int, dma_t *);                 /* optional */
        void    (*enable)(unsigned int, dma_t *);               /* mandatory */
        void    (*disable)(unsigned int, dma_t *);              /* mandatory */
        int     (*residue)(unsigned int, dma_t *);              /* optional */
        int     (*setspeed)(unsigned int, dma_t *, int);        /* optional */
        const char *type;
};

struct dma_struct {
        void            *addr;          /* single DMA address           */
        unsigned long   count;          /* single DMA size              */
        struct scatterlist buf;         /* single DMA                   */
        int             sgcount;        /* number of DMA SG             */
        struct scatterlist *sg;         /* DMA Scatter-Gather List      */

        unsigned int    active:1;       /* Transfer active              */
        unsigned int    invalid:1;      /* Address/Count changed        */

        unsigned int    dma_mode;       /* DMA mode                     */
        int             speed;          /* DMA speed                    */

        unsigned int    lock;           /* Device is allocated          */
        const char      *device_id;     /* Device name                  */

        const struct dma_ops *d_ops;
};

/*
 * isa_dma_add - add an ISA-style DMA channel
 */
extern int isa_dma_add(unsigned int, dma_t *dma);