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