release/src-rt-6.x.4708/linux/linux-2.6.36/arch/arm/include/asm/mach/dma.h

   1 /*
   2  *  arch/arm/include/asm/mach/dma.h
   3  *
   4  *  Copyright (C) 1998-2000 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  *  This header file describes the interface between the generic DMA handler
  11  *  (dma.c) and the architecture-specific DMA backends (dma-*.c)
  12  */
  13
  14 struct dma_struct;
  15 typedef struct dma_struct dma_t;
  16
  17 struct dma_ops {
  18         int     (*request)(unsigned int, dma_t *);              /* optional */
  19         void    (*free)(unsigned int, dma_t *);                 /* optional */
  20         void    (*enable)(unsigned int, dma_t *);               /* mandatory */
  21         void    (*disable)(unsigned int, dma_t *);              /* mandatory */
  22         int     (*residue)(unsigned int, dma_t *);              /* optional */
  23         int     (*setspeed)(unsigned int, dma_t *, int);        /* optional */
  24         const char *type;
  25 };
  26
  27 struct dma_struct {
  28         void            *addr;          /* single DMA address           */
  29         unsigned long   count;          /* single DMA size              */
  30         struct scatterlist buf;         /* single DMA                   */
  31         int             sgcount;        /* number of DMA SG             */
  32         struct scatterlist *sg;         /* DMA Scatter-Gather List      */
  33
  34         unsigned int    active:1;       /* Transfer active              */
  35         unsigned int    invalid:1;      /* Address/Count changed        */
  36
  37         unsigned int    dma_mode;       /* DMA mode                     */
  38         int             speed;          /* DMA speed                    */
  39
  40         unsigned int    lock;           /* Device is allocated          */
  41         const char      *device_id;     /* Device name                  */
  42
  43         const struct dma_ops *d_ops;
  44 };
  45
  46 /*
  47  * isa_dma_add - add an ISA-style DMA channel
  48  */
  49 extern int isa_dma_add(unsigned int, dma_t *dma);
  50
  51 /*
  52  * Add the ISA DMA controller.  Always takes channels 0-7.
  53  */
  54 extern void isa_init_dma(void);