LXR linux/arch/arm/include/asm/mach/dma.h

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 *  arch/arm/include/asm/mach/dma.h
   4 *
   5 *  Copyright (C) 1998-2000 Russell King
   6 *
   7 *  This header file describes the interface between the generic DMA handler
   8 *  (dma.c) and the architecture-specific DMA backends (dma-*.c)
   9 */
  10
  11struct dma_struct;
  12typedef struct dma_struct dma_t;
  13
  14struct dma_ops {
  15        int     (*request)(unsigned int, dma_t *);              /* optional */
  16        void    (*free)(unsigned int, dma_t *);                 /* optional */
  17        void    (*enable)(unsigned int, dma_t *);               /* mandatory */
  18        void    (*disable)(unsigned int, dma_t *);              /* mandatory */
  19        int     (*residue)(unsigned int, dma_t *);              /* optional */
  20        int     (*setspeed)(unsigned int, dma_t *, int);        /* optional */
  21        const char *type;
  22};
  23
  24struct dma_struct {
  25        void            *addr;          /* single DMA address           */
  26        unsigned long   count;          /* single DMA size              */
  27        struct scatterlist buf;         /* single DMA                   */
  28        int             sgcount;        /* number of DMA SG             */
  29        struct scatterlist *sg;         /* DMA Scatter-Gather List      */
  30
  31        unsigned int    active:1;       /* Transfer active              */
  32        unsigned int    invalid:1;      /* Address/Count changed        */
  33
  34        unsigned int    dma_mode;       /* DMA mode                     */
  35        int             speed;          /* DMA speed                    */
  36
  37        unsigned int    lock;           /* Device is allocated          */
  38        const char      *device_id;     /* Device name                  */
  39
  40        const struct dma_ops *d_ops;
  41};
  42
  43/*
  44 * isa_dma_add - add an ISA-style DMA channel
  45 */
  46extern int isa_dma_add(unsigned int, dma_t *dma);
  47
  48/*
  49 * Add the ISA DMA controller.  Always takes channels 0-7.
  50 */
  51extern void isa_init_dma(void);
  52