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  * This is the maximum virtual address which can be DMA'd from.
  14  */
  15 #ifndef MAX_DMA_ADDRESS
  16 #define MAX_DMA_ADDRESS 0xffffffff
  17 #endif
  18
  19 /*
  20  * DMA modes
  21  */
  22 typedef unsigned int dmamode_t;
  23
  24 #define DMA_MODE_MASK   3
  25
  26 #define DMA_MODE_READ    0
  27 #define DMA_MODE_WRITE   1
  28 #define DMA_MODE_CASCADE 2
  29 #define DMA_AUTOINIT     4
  30
  31 extern spinlock_t  dma_spin_lock;
  32
  33 static inline unsigned long claim_dma_lock(void)
  34 {
  35         unsigned long flags;
  36         spin_lock_irqsave(&dma_spin_lock, flags);
  37         return flags;
  38 }
  39
  40 static inline void release_dma_lock(unsigned long flags)
  41 {
  42         spin_unlock_irqrestore(&dma_spin_lock, flags);
  43 }
  44
  45 /* Clear the 'DMA Pointer Flip Flop'.
  46  * Write 0 for LSB/MSB, 1 for MSB/LSB access.
  47  */
  48 #define clear_dma_ff(channel)
  49
  50 /* Set only the page register bits of the transfer address.
  51  *
  52  * NOTE: This is an architecture specific function, and should
  53  *       be hidden from the drivers
  54  */
  55 extern void set_dma_page(dmach_t channel, char pagenr);
  56
  57 /* Request a DMA channel
  58  *
  59  * Some architectures may need to do allocate an interrupt
  60  */
  61 extern int  request_dma(dmach_t channel, const char * device_id);
  62
  63 /* Free a DMA channel
  64  *
  65  * Some architectures may need to do free an interrupt
  66  */
  67 extern void free_dma(dmach_t channel);
  68
  69 /* Enable DMA for this channel
  70  *
  71  * On some architectures, this may have other side effects like
  72  * enabling an interrupt and setting the DMA registers.
  73  */
  74 extern void enable_dma(dmach_t channel);
  75
  76 /* Disable DMA for this channel
  77  *
  78  * On some architectures, this may have other side effects like
  79  * disabling an interrupt or whatever.
  80  */
  81 extern void disable_dma(dmach_t channel);
  82
  83 /* Test whether the specified channel has an active DMA transfer
  84  */
  85 extern int dma_channel_active(dmach_t channel);
  86
  87 /* Set the DMA scatter gather list for this channel
  88  *
  89  * This should not be called if a DMA channel is enabled,
  90  * especially since some DMA architectures don't update the
  91  * DMA address immediately, but defer it to the enable_dma().
  92  */
  93 extern void set_dma_sg(dmach_t channel, struct scatterlist *sg, int nr_sg);
  94
  95 /* Set the DMA address for this channel
  96  *
  97  * This should not be called if a DMA channel is enabled,
  98  * especially since some DMA architectures don't update the
  99  * DMA address immediately, but defer it to the enable_dma().
 100  */
 101 extern void __set_dma_addr(dmach_t channel, void *addr);
 102 #define set_dma_addr(channel, addr)                             \
 103         __set_dma_addr(channel, bus_to_virt(addr))
 104
 105 /* Set the DMA byte count for this channel
 106  *
 107  * This should not be called if a DMA channel is enabled,
 108  * especially since some DMA architectures don't update the
 109  * DMA count immediately, but defer it to the enable_dma().
 110  */
 111 extern void set_dma_count(dmach_t channel, unsigned long count);
 112
 113 /* Set the transfer direction for this channel
 114  *
 115  * This should not be called if a DMA channel is enabled,
 116  * especially since some DMA architectures don't update the
 117  * DMA transfer direction immediately, but defer it to the
 118  * enable_dma().
 119  */
 120 extern void set_dma_mode(dmach_t channel, dmamode_t mode);
 121
 122 /* Set the transfer speed for this channel
 123  */
 124 extern void set_dma_speed(dmach_t channel, int cycle_ns);
 125
 126 /* Get DMA residue count. After a DMA transfer, this
 127  * should return zero. Reading this while a DMA transfer is
 128  * still in progress will return unpredictable results.
 129  * If called before the channel has been used, it may return 1.
 130  * Otherwise, it returns the number of _bytes_ left to transfer.
 131  */
 132 extern int  get_dma_residue(dmach_t channel);
 133
 134 #ifndef NO_DMA
 135 #define NO_DMA  255
 136 #endif
 137
 138 #ifdef CONFIG_PCI
 139 extern int isa_dma_bridge_buggy;
 140 #else
 141 #define isa_dma_bridge_buggy    (0)
 142 #endif
 143
 144 #endif /* _ARM_DMA_H */