1 #ifndef __ASM_ARM_DMA_H 2 #define __ASM_ARM_DMA_H 3 4 #include <asm/memory.h> 5 6 /* 7 * This is the maximum virtual address which can be DMA'd from. 8 */ 9 #ifndef MAX_DMA_ADDRESS 10 #define MAX_DMA_ADDRESS 0xffffffff 11 #endif 12 13 #ifdef CONFIG_ISA_DMA_API 14 /* 15 * This is used to support drivers written for the x86 ISA DMA API. 16 * It should not be re-used except for that purpose. 17 */ 18 #include <linux/spinlock.h> 19 #include <asm/system.h> 20 #include <asm/scatterlist.h> 21 22 typedef unsigned int dmach_t; 23 24 #include <mach/isa-dma.h> 25 26 /* 27 * DMA modes 28 */ 29 typedef unsigned int dmamode_t; 30 31 #define DMA_MODE_MASK 3 32 33 #define DMA_MODE_READ 0 34 #define DMA_MODE_WRITE 1 35 #define DMA_MODE_CASCADE 2 36 #define DMA_AUTOINIT 4 37 38 extern spinlock_t dma_spin_lock; 39 40 static inline unsigned long claim_dma_lock(void) 41 { 42 unsigned long flags; 43 spin_lock_irqsave(&dma_spin_lock, flags); 44 return flags; 45 } 46 47 static inline void release_dma_lock(unsigned long flags) 48 { 49 spin_unlock_irqrestore(&dma_spin_lock, flags); 50 } 51 52 /* Clear the 'DMA Pointer Flip Flop'. 53 * Write 0 for LSB/MSB, 1 for MSB/LSB access. 54 */ 55 #define clear_dma_ff(channel) 56 57 /* Set only the page register bits of the transfer address. 58 * 59 * NOTE: This is an architecture specific function, and should 60 * be hidden from the drivers 61 */ 62 extern void set_dma_page(dmach_t channel, char pagenr); 63 64 /* Request a DMA channel 65 * 66 * Some architectures may need to do allocate an interrupt 67 */ 68 extern int request_dma(dmach_t channel, const char * device_id); 69 70 /* Free a DMA channel 71 * 72 * Some architectures may need to do free an interrupt 73 */ 74 extern void free_dma(dmach_t channel); 75 76 /* Enable DMA for this channel 77 * 78 * On some architectures, this may have other side effects like 79 * enabling an interrupt and setting the DMA registers. 80 */ 81 extern void enable_dma(dmach_t channel); 82 83 /* Disable DMA for this channel 84 * 85 * On some architectures, this may have other side effects like 86 * disabling an interrupt or whatever. 87 */ 88 extern void disable_dma(dmach_t channel); 89 90 /* Test whether the specified channel has an active DMA transfer 91 */ 92 extern int dma_channel_active(dmach_t channel); 93 94 /* Set the DMA scatter gather list 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_sg(dmach_t channel, struct scatterlist *sg, int nr_sg); 101 102 /* Set the DMA address for this channel 103 * 104 * This should not be called if a DMA channel is enabled, 105 * especially since some DMA architectures don't update the 106 * DMA address immediately, but defer it to the enable_dma(). 107 */ 108 extern void __set_dma_addr(dmach_t channel, void *addr); 109 #define set_dma_addr(channel, addr) \ 110 __set_dma_addr(channel, bus_to_virt(addr)) 111 112 /* Set the DMA byte count 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 count immediately, but defer it to the enable_dma(). 117 */ 118 extern void set_dma_count(dmach_t channel, unsigned long count); 119 120 /* Set the transfer direction for this channel 121 * 122 * This should not be called if a DMA channel is enabled, 123 * especially since some DMA architectures don't update the 124 * DMA transfer direction immediately, but defer it to the 125 * enable_dma(). 126 */ 127 extern void set_dma_mode(dmach_t channel, dmamode_t mode); 128 129 /* Set the transfer speed for this channel 130 */ 131 extern void set_dma_speed(dmach_t channel, int cycle_ns); 132 133 /* Get DMA residue count. After a DMA transfer, this 134 * should return zero. Reading this while a DMA transfer is 135 * still in progress will return unpredictable results. 136 * If called before the channel has been used, it may return 1. 137 * Otherwise, it returns the number of _bytes_ left to transfer. 138 */ 139 extern int get_dma_residue(dmach_t channel); 140 141 #ifndef NO_DMA 142 #define NO_DMA 255 143 #endif 144 145 #ifdef CONFIG_PCI 146 extern int isa_dma_bridge_buggy; 147 #else 148 #define isa_dma_bridge_buggy (0) 149 #endif 150 151 #endif /* CONFIG_ISA_DMA_API */ 152 153 #endif /* __ASM_ARM_DMA_H */ 154