include/asm-arm26/dma.h

   1 #ifndef __ASM_ARM_DMA_H
   2 #define __ASM_ARM_DMA_H
   3
   4 typedef 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
  14 typedef struct dma_struct dma_t;
  15 typedef unsigned int dmamode_t;
  16
  17 struct 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
  27 struct 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  */
  53 extern void arch_dma_init(dma_t *dma);
  54
  55 extern 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
  79 extern spinlock_t  dma_spin_lock;
  80
  81 static 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
  88 static 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  */
 103 extern 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  */
 109 extern 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  */
 115 extern 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  */
 122 extern 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  */
 129 extern void disable_dma(dmach_t channel);
 130
 131 /* Test whether the specified channel has an active DMA transfer
 132  */
 133 extern 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  */
 141 extern 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  */
 149 extern 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  */
 157 extern 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  */
 166 extern void set_dma_mode(dmach_t channel, dmamode_t mode);
 167
 168 /* Set the transfer speed for this channel
 169  */
 170 extern 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  */
 178 extern 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 */