1#ifndef __ASM_ARM_DMA_H 2#define __ASM_ARM_DMA_H 3 4/* 5 * This is the maximum virtual address which can be DMA'd from. 6 */ 7#ifndef CONFIG_ZONE_DMA 8#define MAX_DMA_ADDRESS 0xffffffffUL 9#else 10#define MAX_DMA_ADDRESS ({ \ 11 extern phys_addr_t arm_dma_zone_size; \ 12 arm_dma_zone_size && arm_dma_zone_size < (0x10000000 - PAGE_OFFSET) ? \ 13 (PAGE_OFFSET + arm_dma_zone_size) : 0xffffffffUL; }) 14#endif 15 16#ifdef CONFIG_ISA_DMA_API 17/* 18 * This is used to support drivers written for the x86 ISA DMA API. 19 * It should not be re-used except for that purpose. 20 */ 21#include <linux/spinlock.h> 22#include <asm/scatterlist.h> 23 24#include <mach/isa-dma.h> 25 26/* 27 * The DMA modes reflect the settings for the ISA DMA controller 28 */ 29#define DMA_MODE_MASK 0xcc 30 31#define DMA_MODE_READ 0x44 32#define DMA_MODE_WRITE 0x48 33#define DMA_MODE_CASCADE 0xc0 34#define DMA_AUTOINIT 0x10 35 36extern raw_spinlock_t dma_spin_lock; 37 38static inline unsigned long claim_dma_lock(void) 39{ 40 unsigned long flags; 41 raw_spin_lock_irqsave(&dma_spin_lock, flags); 42 return flags; 43} 44 45static inline void release_dma_lock(unsigned long flags) 46{ 47 raw_spin_unlock_irqrestore(&dma_spin_lock, flags); 48} 49 50/* Clear the 'DMA Pointer Flip Flop'. 51 * Write 0 for LSB/MSB, 1 for MSB/LSB access. 52 */ 53#define clear_dma_ff(chan) 54 55/* Set only the page register bits of the transfer address. 56 * 57 * NOTE: This is an architecture specific function, and should 58 * be hidden from the drivers 59 */ 60extern void set_dma_page(unsigned int chan, char pagenr); 61 62/* Request a DMA channel 63 * 64 * Some architectures may need to do allocate an interrupt 65 */ 66extern int request_dma(unsigned int chan, const char * device_id); 67 68/* Free a DMA channel 69 * 70 * Some architectures may need to do free an interrupt 71 */ 72extern void free_dma(unsigned int chan); 73 74/* Enable DMA for this channel 75 * 76 * On some architectures, this may have other side effects like 77 * enabling an interrupt and setting the DMA registers. 78 */ 79extern void enable_dma(unsigned int chan); 80 81/* Disable DMA for this channel 82 * 83 * On some architectures, this may have other side effects like 84 * disabling an interrupt or whatever. 85 */ 86extern void disable_dma(unsigned int chan); 87 88/* Test whether the specified channel has an active DMA transfer 89 */ 90extern int dma_channel_active(unsigned int chan); 91 92/* Set the DMA scatter gather list for this channel 93 * 94 * This should not be called if a DMA channel is enabled, 95 * especially since some DMA architectures don't update the 96 * DMA address immediately, but defer it to the enable_dma(). 97 */ 98extern void set_dma_sg(unsigned int chan, struct scatterlist *sg, int nr_sg); 99 100/* Set the DMA address for this channel 101 * 102 * This should not be called if a DMA channel is enabled, 103 * especially since some DMA architectures don't update the 104 * DMA address immediately, but defer it to the enable_dma(). 105 */ 106extern void __set_dma_addr(unsigned int chan, void *addr); 107#define set_dma_addr(chan, addr) \ 108 __set_dma_addr(chan, (void *)__bus_to_virt(addr)) 109 110/* Set the DMA byte count for this channel 111 * 112 * This should not be called if a DMA channel is enabled, 113 * especially since some DMA architectures don't update the 114 * DMA count immediately, but defer it to the enable_dma(). 115 */ 116extern void set_dma_count(unsigned int chan, unsigned long count); 117 118/* Set the transfer direction for this channel 119 * 120 * This should not be called if a DMA channel is enabled, 121 * especially since some DMA architectures don't update the 122 * DMA transfer direction immediately, but defer it to the 123 * enable_dma(). 124 */ 125extern void set_dma_mode(unsigned int chan, unsigned int mode); 126 127/* Set the transfer speed for this channel 128 */ 129extern void set_dma_speed(unsigned int chan, int cycle_ns); 130 131/* Get DMA residue count. After a DMA transfer, this 132 * should return zero. Reading this while a DMA transfer is 133 * still in progress will return unpredictable results. 134 * If called before the channel has been used, it may return 1. 135 * Otherwise, it returns the number of _bytes_ left to transfer. 136 */ 137extern int get_dma_residue(unsigned int chan); 138 139#ifndef NO_DMA 140#define NO_DMA 255 141#endif 142 143#endif /* CONFIG_ISA_DMA_API */ 144 145#ifdef CONFIG_PCI 146extern int isa_dma_bridge_buggy; 147#else 148#define isa_dma_bridge_buggy (0) 149#endif 150 151#endif /* __ASM_ARM_DMA_H */ 152