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
36 extern raw_spinlock_t dma_spin_lock;
37
claim_dma_lock(void)38 static 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
release_dma_lock(unsigned long flags)45 static 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 */
60 extern 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 */
66 extern 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 */
72 extern 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 */
79 extern 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 */
86 extern void disable_dma(unsigned int chan);
87
88 /* Test whether the specified channel has an active DMA transfer
89 */
90 extern 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 */
98 extern 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 */
106 extern 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 */
116 extern 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 */
125 extern void set_dma_mode(unsigned int chan, unsigned int mode);
126
127 /* Set the transfer speed for this channel
128 */
129 extern 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 */
137 extern 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
146 extern int isa_dma_bridge_buggy;
147 #else
148 #define isa_dma_bridge_buggy (0)
149 #endif
150
151 #endif /* __ASM_ARM_DMA_H */
152