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