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 <linux/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 */