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/scatterlist.h>
  10 #include <asm/arch/dma.h>
  11
  12 /*
  13  * DMA modes
  14  */
  15 typedef unsigned int dmamode_t;
  16
  17 #define DMA_MODE_MASK   3
  18
  19 #define DMA_MODE_READ    0
  20 #define DMA_MODE_WRITE   1
  21 #define DMA_MODE_CASCADE 2
  22 #define DMA_AUTOINIT     4
  23
  24 extern spinlock_t  dma_spin_lock;
  25
  26 static inline unsigned long claim_dma_lock(void)
  27 {
  28         unsigned long flags;
  29         spin_lock_irqsave(&dma_spin_lock, flags);
  30         return flags;
  31 }
  32
  33 static inline void release_dma_lock(unsigned long flags)
  34 {
  35         spin_unlock_irqrestore(&dma_spin_lock, flags);
  36 }
  37
  38 /* Clear the 'DMA Pointer Flip Flop'.
  39  * Write 0 for LSB/MSB, 1 for MSB/LSB access.
  40  */
  41 #define clear_dma_ff(channel)
  42
  43 /* Set only the page register bits of the transfer address.
  44  *
  45  * NOTE: This is an architecture specific function, and should
  46  *       be hidden from the drivers
  47  */
  48 extern void set_dma_page(dmach_t channel, char pagenr);
  49
  50 /* Request a DMA channel
  51  *
  52  * Some architectures may need to do allocate an interrupt
  53  */
  54 extern int  request_dma(dmach_t channel, const char * device_id);
  55
  56 /* Free a DMA channel
  57  *
  58  * Some architectures may need to do free an interrupt
  59  */
  60 extern void free_dma(dmach_t channel);
  61
  62 /* Enable DMA for this channel
  63  *
  64  * On some architectures, this may have other side effects like
  65  * enabling an interrupt and setting the DMA registers.
  66  */
  67 extern void enable_dma(dmach_t channel);
  68
  69 /* Disable DMA for this channel
  70  *
  71  * On some architectures, this may have other side effects like
  72  * disabling an interrupt or whatever.
  73  */
  74 extern void disable_dma(dmach_t channel);
  75
  76 /* Test whether the specified channel has an active DMA transfer
  77  */
  78 extern int dma_channel_active(dmach_t channel);
  79
  80 /* Set the DMA scatter gather list for this channel
  81  *
  82  * This should not be called if a DMA channel is enabled,
  83  * especially since some DMA architectures don't update the
  84  * DMA address immediately, but defer it to the enable_dma().
  85  */
  86 extern void set_dma_sg(dmach_t channel, struct scatterlist *sg, int nr_sg);
  87
  88 /* Set the DMA address for this channel
  89  *
  90  * This should not be called if a DMA channel is enabled,
  91  * especially since some DMA architectures don't update the
  92  * DMA address immediately, but defer it to the enable_dma().
  93  */
  94 extern void set_dma_addr(dmach_t channel, unsigned long physaddr);
  95
  96 /* Set the DMA byte count for this channel
  97  *
  98  * This should not be called if a DMA channel is enabled,
  99  * especially since some DMA architectures don't update the
 100  * DMA count immediately, but defer it to the enable_dma().
 101  */
 102 extern void set_dma_count(dmach_t channel, unsigned long count);
 103
 104 /* Set the transfer direction for this channel
 105  *
 106  * This should not be called if a DMA channel is enabled,
 107  * especially since some DMA architectures don't update the
 108  * DMA transfer direction immediately, but defer it to the
 109  * enable_dma().
 110  */
 111 extern void set_dma_mode(dmach_t channel, dmamode_t mode);
 112
 113 /* Set the transfer speed for this channel
 114  */
 115 extern void set_dma_speed(dmach_t channel, int cycle_ns);
 116
 117 /* Get DMA residue count. After a DMA transfer, this
 118  * should return zero. Reading this while a DMA transfer is
 119  * still in progress will return unpredictable results.
 120  * If called before the channel has been used, it may return 1.
 121  * Otherwise, it returns the number of _bytes_ left to transfer.
 122  */
 123 extern int  get_dma_residue(dmach_t channel);
 124
 125 #ifndef NO_DMA
 126 #define NO_DMA  255
 127 #endif
 128
 129 #ifdef CONFIG_PCI
 130 extern int isa_dma_bridge_buggy;
 131 #else
 132 #define isa_dma_bridge_buggy    (0)
 133 #endif
 134
 135 #endif /* _ARM_DMA_H */