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
  11 struct dma_struct;
  12 typedef struct dma_struct dma_t;
  13
  14 struct 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
  24 struct 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  */
  46 extern int isa_dma_add(unsigned int, dma_t *dma);
  47
  48 /*
  49  * Add the ISA DMA controller.  Always takes channels 0-7.
  50  */
  51 extern void isa_init_dma(void);