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Linux kernel mirror (for testing)
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linux
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
22typedef unsigned int dmach_t;
23
24#include <mach/isa-dma.h>
25
26/*
27 * DMA modes
28 */
29typedef 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
38extern spinlock_t dma_spin_lock;
39
40static 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
47static 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 */
62extern 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 */
68extern 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 */
74extern 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 */
81extern 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 */
88extern void disable_dma(dmach_t channel);
89
90/* Test whether the specified channel has an active DMA transfer
91 */
92extern 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 */
100extern 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 */
108extern 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 */
118extern 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 */
127extern void set_dma_mode(dmach_t channel, dmamode_t mode);
128
129/* Set the transfer speed for this channel
130 */
131extern 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 */
139extern int get_dma_residue(dmach_t channel);
140
141#ifndef NO_DMA
142#define NO_DMA 255
143#endif
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 /* CONFIG_ISA_DMA_API */
152
153#endif /* __ASM_ARM_DMA_H */