include/asm-arm/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 #include <asm/arch/dma.h>
  12
  13 /*
  14  * DMA modes
  15  */
  16 typedef unsigned int dmamode_t;
  17
  18 #define DMA_MODE_MASK   3
  19
  20 #define DMA_MODE_READ    0
  21 #define DMA_MODE_WRITE   1
  22 #define DMA_MODE_CASCADE 2
  23 #define DMA_AUTOINIT     4
  24
  25 typedef struct {
  26         unsigned long address;
  27         unsigned long length;
  28 } dmasg_t;
  29
  30 extern spinlock_t  dma_spin_lock;
  31
  32 extern __inline__ unsigned long claim_dma_lock(void)
  33 {
  34         unsigned long flags;
  35         spin_lock_irqsave(&dma_spin_lock, flags);
  36         return flags;
  37 }
  38
  39 extern __inline__ void release_dma_lock(unsigned long flags)
  40 {
  41         spin_unlock_irqrestore(&dma_spin_lock, flags);
  42 }
  43
  44 /* Clear the 'DMA Pointer Flip Flop'.
  45  * Write 0 for LSB/MSB, 1 for MSB/LSB access.
  46  */
  47 #define clear_dma_ff(channel)
  48
  49 /* Set only the page register bits of the transfer address.
  50  *
  51  * NOTE: This is an architecture specific function, and should
  52  *       be hidden from the drivers
  53  */
  54 extern void set_dma_page(dmach_t channel, char pagenr);
  55
  56 /* Request a DMA channel
  57  *
  58  * Some architectures may need to do allocate an interrupt
  59  */
  60 extern int  request_dma(dmach_t channel, const char * device_id);
  61
  62 /* Free a DMA channel
  63  *
  64  * Some architectures may need to do free an interrupt
  65  */
  66 extern void free_dma(dmach_t channel);
  67
  68 /* Enable DMA for this channel
  69  *
  70  * On some architectures, this may have other side effects like
  71  * enabling an interrupt and setting the DMA registers.
  72  */
  73 extern void enable_dma(dmach_t channel);
  74
  75 /* Disable DMA for this channel
  76  *
  77  * On some architectures, this may have other side effects like
  78  * disabling an interrupt or whatever.
  79  */
  80 extern void disable_dma(dmach_t channel);
  81
  82 /* Set the DMA scatter gather list for this channel
  83  *
  84  * This should not be called if a DMA channel is enabled,
  85  * especially since some DMA architectures don't update the
  86  * DMA address immediately, but defer it to the enable_dma().
  87  */
  88 extern void set_dma_sg(dmach_t channel, dmasg_t *sg, int nr_sg);
  89
  90 /* Set the DMA address for this channel
  91  *
  92  * This should not be called if a DMA channel is enabled,
  93  * especially since some DMA architectures don't update the
  94  * DMA address immediately, but defer it to the enable_dma().
  95  */
  96 extern void set_dma_addr(dmach_t channel, unsigned long physaddr);
  97
  98 /* Set the DMA byte count for this channel
  99  *
 100  * This should not be called if a DMA channel is enabled,
 101  * especially since some DMA architectures don't update the
 102  * DMA count immediately, but defer it to the enable_dma().
 103  */
 104 extern void set_dma_count(dmach_t channel, unsigned long count);
 105
 106 /* Set the transfer direction for this channel
 107  *
 108  * This should not be called if a DMA channel is enabled,
 109  * especially since some DMA architectures don't update the
 110  * DMA transfer direction immediately, but defer it to the
 111  * enable_dma().
 112  */
 113 extern void set_dma_mode(dmach_t channel, dmamode_t mode);
 114
 115 /* Set the transfer speed for this channel
 116  */
 117 extern void set_dma_speed(dmach_t channel, int cycle_ns);
 118
 119 /* Get DMA residue count. After a DMA transfer, this
 120  * should return zero. Reading this while a DMA transfer is
 121  * still in progress will return unpredictable results.
 122  * If called before the channel has been used, it may return 1.
 123  * Otherwise, it returns the number of _bytes_ left to transfer.
 124  */
 125 extern int  get_dma_residue(dmach_t channel);
 126
 127 #ifndef NO_DMA
 128 #define NO_DMA  255
 129 #endif
 130
 131 #ifdef CONFIG_PCI
 132 extern int isa_dma_bridge_buggy;
 133 #else
 134 #define isa_dma_bridge_buggy    (0)
 135 #endif
 136
 137 #endif /* _ARM_DMA_H */