1 #ifndef __ASM_ARM_DMA_H 2 #define __ASM_ARM_DMA_H 3 4 typedef unsigned int dmach_t; 5 6 #include <linux/spinlock.h> 7 #include <asm/system.h> 8 #include <asm/scatterlist.h> 9 #include <asm/arch/dma.h> 10 11 /* 12 * This is the maximum virtual address which can be DMA'd from. 13 */ 14 #ifndef MAX_DMA_ADDRESS 15 #define MAX_DMA_ADDRESS 0xffffffff 16 #endif 17 18 /* 19 * DMA modes 20 */ 21 typedef unsigned int dmamode_t; 22 23 #define DMA_MODE_MASK 3 24 25 #define DMA_MODE_READ 0 26 #define DMA_MODE_WRITE 1 27 #define DMA_MODE_CASCADE 2 28 #define DMA_AUTOINIT 4 29 30 extern spinlock_t dma_spin_lock; 31 32 static 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 static 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 /* Test whether the specified channel has an active DMA transfer 83 */ 84 extern int dma_channel_active(dmach_t channel); 85 86 /* Set the DMA scatter gather list for this channel 87 * 88 * This should not be called if a DMA channel is enabled, 89 * especially since some DMA architectures don't update the 90 * DMA address immediately, but defer it to the enable_dma(). 91 */ 92 extern void set_dma_sg(dmach_t channel, struct scatterlist *sg, int nr_sg); 93 94 /* Set the DMA address for this channel 95 * 96 * This should not be called if a DMA channel is enabled, 97 * especially since some DMA architectures don't update the 98 * DMA address immediately, but defer it to the enable_dma(). 99 */ 100 extern void __set_dma_addr(dmach_t channel, void *addr); 101 #define set_dma_addr(channel, addr) \ 102 __set_dma_addr(channel, bus_to_virt(addr)) 103 104 /* Set the DMA byte count 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 count immediately, but defer it to the enable_dma(). 109 */ 110 extern void set_dma_count(dmach_t channel, unsigned long count); 111 112 /* Set the transfer direction for this channel 113 * 114 * This should not be called if a DMA channel is enabled, 115 * especially since some DMA architectures don't update the 116 * DMA transfer direction immediately, but defer it to the 117 * enable_dma(). 118 */ 119 extern void set_dma_mode(dmach_t channel, dmamode_t mode); 120 121 /* Set the transfer speed for this channel 122 */ 123 extern void set_dma_speed(dmach_t channel, int cycle_ns); 124 125 /* Get DMA residue count. After a DMA transfer, this 126 * should return zero. Reading this while a DMA transfer is 127 * still in progress will return unpredictable results. 128 * If called before the channel has been used, it may return 1. 129 * Otherwise, it returns the number of _bytes_ left to transfer. 130 */ 131 extern int get_dma_residue(dmach_t channel); 132 133 #ifndef NO_DMA 134 #define NO_DMA 255 135 #endif 136 137 #ifdef CONFIG_PCI 138 extern int isa_dma_bridge_buggy; 139 #else 140 #define isa_dma_bridge_buggy (0) 141 #endif 142 143 #endif /* _ARM_DMA_H */ 144
