1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_ARM_DMA_H
#define __ASM_ARM_DMA_H
/*
* This is the maximum virtual address which can be DMA'd from.
*/
#ifndef CONFIG_ZONE_DMA
#define MAX_DMA_ADDRESS 0xffffffffUL
#else
#define MAX_DMA_ADDRESS ({ \
extern phys_addr_t arm_dma_zone_size; \
arm_dma_zone_size && arm_dma_zone_size < (0x100000000ULL - PAGE_OFFSET) ? \
(PAGE_OFFSET + arm_dma_zone_size) : 0xffffffffUL; })
#endif
#ifdef CONFIG_ISA_DMA_API
/*
* This is used to support drivers written for the x86 ISA DMA API.
* It should not be re-used except for that purpose.
*/
#include <linux/spinlock.h>
#include <linux/scatterlist.h>
#include <mach/isa-dma.h>
/*
* The DMA modes reflect the settings for the ISA DMA controller
*/
#define DMA_MODE_MASK 0xcc
#define DMA_MODE_READ 0x44
#define DMA_MODE_WRITE 0x48
#define DMA_MODE_CASCADE 0xc0
#define DMA_AUTOINIT 0x10
extern raw_spinlock_t dma_spin_lock;
static inline unsigned long claim_dma_lock(void)
{
unsigned long flags;
raw_spin_lock_irqsave(&dma_spin_lock, flags);
return flags;
}
static inline void release_dma_lock(unsigned long flags)
{
raw_spin_unlock_irqrestore(&dma_spin_lock, flags);
}
/* Clear the 'DMA Pointer Flip Flop'.
* Write 0 for LSB/MSB, 1 for MSB/LSB access.
*/
#define clear_dma_ff(chan)
/* Set only the page register bits of the transfer address.
*
* NOTE: This is an architecture specific function, and should
* be hidden from the drivers
*/
extern void set_dma_page(unsigned int chan, char pagenr);
/* Request a DMA channel
*
* Some architectures may need to do allocate an interrupt
*/
extern int request_dma(unsigned int chan, const char * device_id);
/* Free a DMA channel
*
* Some architectures may need to do free an interrupt
*/
extern void free_dma(unsigned int chan);
/* Enable DMA for this channel
*
* On some architectures, this may have other side effects like
* enabling an interrupt and setting the DMA registers.
*/
extern void enable_dma(unsigned int chan);
/* Disable DMA for this channel
*
* On some architectures, this may have other side effects like
* disabling an interrupt or whatever.
*/
extern void disable_dma(unsigned int chan);
/* Test whether the specified channel has an active DMA transfer
*/
extern int dma_channel_active(unsigned int chan);
/* Set the DMA scatter gather list for this channel
*
* This should not be called if a DMA channel is enabled,
* especially since some DMA architectures don't update the
* DMA address immediately, but defer it to the enable_dma().
*/
extern void set_dma_sg(unsigned int chan, struct scatterlist *sg, int nr_sg);
/* Set the DMA address for this channel
*
* This should not be called if a DMA channel is enabled,
* especially since some DMA architectures don't update the
* DMA address immediately, but defer it to the enable_dma().
*/
extern void __set_dma_addr(unsigned int chan, void *addr);
#define set_dma_addr(chan, addr) \
__set_dma_addr(chan, (void *)__bus_to_virt(addr))
/* Set the DMA byte count for this channel
*
* This should not be called if a DMA channel is enabled,
* especially since some DMA architectures don't update the
* DMA count immediately, but defer it to the enable_dma().
*/
extern void set_dma_count(unsigned int chan, unsigned long count);
/* Set the transfer direction for this channel
*
* This should not be called if a DMA channel is enabled,
* especially since some DMA architectures don't update the
* DMA transfer direction immediately, but defer it to the
* enable_dma().
*/
extern void set_dma_mode(unsigned int chan, unsigned int mode);
/* Set the transfer speed for this channel
*/
extern void set_dma_speed(unsigned int chan, int cycle_ns);
/* Get DMA residue count. After a DMA transfer, this
* should return zero. Reading this while a DMA transfer is
* still in progress will return unpredictable results.
* If called before the channel has been used, it may return 1.
* Otherwise, it returns the number of _bytes_ left to transfer.
*/
extern int get_dma_residue(unsigned int chan);
#ifndef NO_DMA
#define NO_DMA 255
#endif
#endif /* CONFIG_ISA_DMA_API */
#ifdef CONFIG_PCI
extern int isa_dma_bridge_buggy;
#else
#define isa_dma_bridge_buggy (0)
#endif
#endif /* __ASM_ARM_DMA_H */
|
