LXR linux/include/asm-arm26/dma.h

   1#ifndef __ASM_ARM_DMA_H
   2#define __ASM_ARM_DMA_H
   3
   4typedef unsigned int dmach_t;
   5
   6#include <linux/config.h>
   7#include <linux/spinlock.h>
   8#include <asm/system.h>
   9#include <asm/memory.h>
  10#include <asm/scatterlist.h>
  11
  12// FIXME - do we really need this? arm26 cant do 'proper' DMA
  13
  14typedef struct dma_struct dma_t;
  15typedef unsigned int dmamode_t;
  16
  17struct dma_ops {
  18        int     (*request)(dmach_t, dma_t *);           /* optional */
  19        void    (*free)(dmach_t, dma_t *);              /* optional */
  20        void    (*enable)(dmach_t, dma_t *);            /* mandatory */
  21        void    (*disable)(dmach_t, dma_t *);           /* mandatory */
  22        int     (*residue)(dmach_t, dma_t *);           /* optional */
  23        int     (*setspeed)(dmach_t, dma_t *, int);     /* optional */
  24        char    *type;
  25};
  26
  27struct dma_struct {
  28        struct scatterlist buf;         /* single DMA                   */
  29        int             sgcount;        /* number of DMA SG             */
  30        struct scatterlist *sg;         /* DMA Scatter-Gather List      */
  31
  32        unsigned int    active:1;       /* Transfer active              */
  33        unsigned int    invalid:1;      /* Address/Count changed        */
  34        unsigned int    using_sg:1;     /* using scatter list?          */
  35        dmamode_t       dma_mode;       /* DMA mode                     */
  36        int             speed;          /* DMA speed                    */
  37
  38        unsigned int    lock;           /* Device is allocated          */
  39        const char      *device_id;     /* Device name                  */
  40
  41        unsigned int    dma_base;       /* Controller base address      */
  42        int             dma_irq;        /* Controller IRQ               */
  43        int             state;          /* Controller state             */
  44        struct scatterlist cur_sg;      /* Current controller buffer    */
  45
  46        struct dma_ops  *d_ops;
  47};
  48
  49/* Prototype: void arch_dma_init(dma)
  50 * Purpose  : Initialise architecture specific DMA
  51 * Params   : dma - pointer to array of DMA structures
  52 */
  53extern void arch_dma_init(dma_t *dma);
  54
  55extern void isa_init_dma(dma_t *dma);
  56
  57
  58#define MAX_DMA_ADDRESS         0x03000000
  59#define MAX_DMA_CHANNELS        3
  60
  61/* ARC */
  62#define DMA_VIRTUAL_FLOPPY0     0
  63#define DMA_VIRTUAL_FLOPPY1     1
  64#define DMA_VIRTUAL_SOUND       2
  65
  66/* A5K */
  67#define DMA_FLOPPY              0
  68
  69/*
  70 * DMA modes
  71 */
  72#define DMA_MODE_MASK   3
  73
  74#define DMA_MODE_READ    0
  75#define DMA_MODE_WRITE   1
  76#define DMA_MODE_CASCADE 2
  77#define DMA_AUTOINIT     4
  78
  79extern spinlock_t  dma_spin_lock;
  80
  81static inline unsigned long claim_dma_lock(void)
  82{
  83        unsigned long flags;
  84        spin_lock_irqsave(&dma_spin_lock, flags);
  85        return flags;
  86}
  87
  88static inline void release_dma_lock(unsigned long flags)
  89{
  90        spin_unlock_irqrestore(&dma_spin_lock, flags);
  91}
  92
  93/* Clear the 'DMA Pointer Flip Flop'.
  94 * Write 0 for LSB/MSB, 1 for MSB/LSB access.
  95 */
  96#define clear_dma_ff(channel)
  97
  98/* Set only the page register bits of the transfer address.
  99 *
 100 * NOTE: This is an architecture specific function, and should
 101 *       be hidden from the drivers
 102 */
 103extern void set_dma_page(dmach_t channel, char pagenr);
 104
 105/* Request a DMA channel
 106 *
 107 * Some architectures may need to do allocate an interrupt
 108 */
 109extern int  request_dma(dmach_t channel, const char * device_id);
 110
 111/* Free a DMA channel
 112 *
 113 * Some architectures may need to do free an interrupt
 114 */
 115extern void free_dma(dmach_t channel);
 116
 117/* Enable DMA for this channel
 118 *
 119 * On some architectures, this may have other side effects like
 120 * enabling an interrupt and setting the DMA registers.
 121 */
 122extern void enable_dma(dmach_t channel);
 123
 124/* Disable DMA for this channel
 125 *
 126 * On some architectures, this may have other side effects like
 127 * disabling an interrupt or whatever.
 128 */
 129extern void disable_dma(dmach_t channel);
 130
 131/* Test whether the specified channel has an active DMA transfer
 132 */
 133extern int dma_channel_active(dmach_t channel);
 134
 135/* Set the DMA scatter gather list for this channel
 136 *
 137 * This should not be called if a DMA channel is enabled,
 138 * especially since some DMA architectures don't update the
 139 * DMA address immediately, but defer it to the enable_dma().
 140 */
 141extern void set_dma_sg(dmach_t channel, struct scatterlist *sg, int nr_sg);
 142
 143/* Set the DMA address for this channel
 144 *
 145 * This should not be called if a DMA channel is enabled,
 146 * especially since some DMA architectures don't update the
 147 * DMA address immediately, but defer it to the enable_dma().
 148 */
 149extern void set_dma_addr(dmach_t channel, unsigned long physaddr);
 150
 151/* Set the DMA byte count for this channel
 152 *
 153 * This should not be called if a DMA channel is enabled,
 154 * especially since some DMA architectures don't update the
 155 * DMA count immediately, but defer it to the enable_dma().
 156 */
 157extern void set_dma_count(dmach_t channel, unsigned long count);
 158
 159/* Set the transfer direction for this channel
 160 *
 161 * This should not be called if a DMA channel is enabled,
 162 * especially since some DMA architectures don't update the
 163 * DMA transfer direction immediately, but defer it to the
 164 * enable_dma().
 165 */
 166extern void set_dma_mode(dmach_t channel, dmamode_t mode);
 167
 168/* Set the transfer speed for this channel
 169 */
 170extern void set_dma_speed(dmach_t channel, int cycle_ns);
 171
 172/* Get DMA residue count. After a DMA transfer, this
 173 * should return zero. Reading this while a DMA transfer is
 174 * still in progress will return unpredictable results.
 175 * If called before the channel has been used, it may return 1.
 176 * Otherwise, it returns the number of _bytes_ left to transfer.
 177 */
 178extern int  get_dma_residue(dmach_t channel);
 179
 180#ifndef NO_DMA
 181#define NO_DMA  255
 182#endif
 183
 184#endif /* _ARM_DMA_H */
 185