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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
|
/* $Id: dma.h,v 1.7 1992/12/14 00:29:34 root Exp root $
* linux/include/asm/dma.h: Defines for using and allocating dma channels.
* Written by Hennus Bergman, 1992.
* High DMA channel support & info by Hannu Savolainen
* and John Boyd, Nov. 1992.
*/
#ifndef _ASM_APOLLO_DMA_H
#define _ASM_APOLLO_DMA_H
#include <asm/apollohw.h> /* need byte IO */
#include <linux/spinlock.h> /* And spinlocks */
#include <linux/delay.h>
#define dma_outb(val,addr) (*((volatile unsigned char *)(addr+IO_BASE)) = (val))
#define dma_inb(addr) (*((volatile unsigned char *)(addr+IO_BASE)))
/*
* NOTES about DMA transfers:
*
* controller 1: channels 0-3, byte operations, ports 00-1F
* controller 2: channels 4-7, word operations, ports C0-DF
*
* - ALL registers are 8 bits only, regardless of transfer size
* - channel 4 is not used - cascades 1 into 2.
* - channels 0-3 are byte - addresses/counts are for physical bytes
* - channels 5-7 are word - addresses/counts are for physical words
* - transfers must not cross physical 64K (0-3) or 128K (5-7) boundaries
* - transfer count loaded to registers is 1 less than actual count
* - controller 2 offsets are all even (2x offsets for controller 1)
* - page registers for 5-7 don't use data bit 0, represent 128K pages
* - page registers for 0-3 use bit 0, represent 64K pages
*
* DMA transfers are limited to the lower 16MB of _physical_ memory.
* Note that addresses loaded into registers must be _physical_ addresses,
* not logical addresses (which may differ if paging is active).
*
* Address mapping for channels 0-3:
*
* A23 ... A16 A15 ... A8 A7 ... A0 (Physical addresses)
* | ... | | ... | | ... |
* | ... | | ... | | ... |
* | ... | | ... | | ... |
* P7 ... P0 A7 ... A0 A7 ... A0
* | Page | Addr MSB | Addr LSB | (DMA registers)
*
* Address mapping for channels 5-7:
*
* A23 ... A17 A16 A15 ... A9 A8 A7 ... A1 A0 (Physical addresses)
* | ... | \ \ ... \ \ \ ... \ \
* | ... | \ \ ... \ \ \ ... \ (not used)
* | ... | \ \ ... \ \ \ ... \
* P7 ... P1 (0) A7 A6 ... A0 A7 A6 ... A0
* | Page | Addr MSB | Addr LSB | (DMA registers)
*
* Again, channels 5-7 transfer _physical_ words (16 bits), so addresses
* and counts _must_ be word-aligned (the lowest address bit is _ignored_ at
* the hardware level, so odd-byte transfers aren't possible).
*
* Transfer count (_not # bytes_) is limited to 64K, represented as actual
* count - 1 : 64K => 0xFFFF, 1 => 0x0000. Thus, count is always 1 or more,
* and up to 128K bytes may be transferred on channels 5-7 in one operation.
*
*/
#define MAX_DMA_CHANNELS 8
/* The maximum address that we can perform a DMA transfer to on this platform */#define MAX_DMA_ADDRESS (PAGE_OFFSET+0x1000000)
/* 8237 DMA controllers */
#define IO_DMA1_BASE 0x10C00 /* 8 bit slave DMA, channels 0..3 */
#define IO_DMA2_BASE 0x10D00 /* 16 bit master DMA, ch 4(=slave input)..7 */
/* DMA controller registers */
#define DMA1_CMD_REG (IO_DMA1_BASE+0x08) /* command register (w) */
#define DMA1_STAT_REG (IO_DMA1_BASE+0x08) /* status register (r) */
#define DMA1_REQ_REG (IO_DMA1_BASE+0x09) /* request register (w) */
#define DMA1_MASK_REG (IO_DMA1_BASE+0x0A) /* single-channel mask (w) */
#define DMA1_MODE_REG (IO_DMA1_BASE+0x0B) /* mode register (w) */
#define DMA1_CLEAR_FF_REG (IO_DMA1_BASE+0x0C) /* clear pointer flip-flop (w) */
#define DMA1_TEMP_REG (IO_DMA1_BASE+0x0D) /* Temporary Register (r) */
#define DMA1_RESET_REG (IO_DMA1_BASE+0x0D) /* Master Clear (w) */
#define DMA1_CLR_MASK_REG (IO_DMA1_BASE+0x0E) /* Clear Mask */
#define DMA1_MASK_ALL_REG (IO_DMA1_BASE+0x0F) /* all-channels mask (w) */
#define DMA2_CMD_REG (IO_DMA2_BASE+0x10) /* command register (w) */
#define DMA2_STAT_REG (IO_DMA2_BASE+0x10) /* status register (r) */
#define DMA2_REQ_REG (IO_DMA2_BASE+0x12) /* request register (w) */
#define DMA2_MASK_REG (IO_DMA2_BASE+0x14) /* single-channel mask (w) */
#define DMA2_MODE_REG (IO_DMA2_BASE+0x16) /* mode register (w) */
#define DMA2_CLEAR_FF_REG (IO_DMA2_BASE+0x18) /* clear pointer flip-flop (w) */
#define DMA2_TEMP_REG (IO_DMA2_BASE+0x1A) /* Temporary Register (r) */
#define DMA2_RESET_REG (IO_DMA2_BASE+0x1A) /* Master Clear (w) */
#define DMA2_CLR_MASK_REG (IO_DMA2_BASE+0x1C) /* Clear Mask */
#define DMA2_MASK_ALL_REG (IO_DMA2_BASE+0x1E) /* all-channels mask (w) */
#define DMA_ADDR_0 (IO_DMA1_BASE+0x00) /* DMA address registers */
#define DMA_ADDR_1 (IO_DMA1_BASE+0x02)
#define DMA_ADDR_2 (IO_DMA1_BASE+0x04)
#define DMA_ADDR_3 (IO_DMA1_BASE+0x06)
#define DMA_ADDR_4 (IO_DMA2_BASE+0x00)
#define DMA_ADDR_5 (IO_DMA2_BASE+0x04)
#define DMA_ADDR_6 (IO_DMA2_BASE+0x08)
#define DMA_ADDR_7 (IO_DMA2_BASE+0x0C)
#define DMA_CNT_0 (IO_DMA1_BASE+0x01) /* DMA count registers */
#define DMA_CNT_1 (IO_DMA1_BASE+0x03)
#define DMA_CNT_2 (IO_DMA1_BASE+0x05)
#define DMA_CNT_3 (IO_DMA1_BASE+0x07)
#define DMA_CNT_4 (IO_DMA2_BASE+0x02)
#define DMA_CNT_5 (IO_DMA2_BASE+0x06)
#define DMA_CNT_6 (IO_DMA2_BASE+0x0A)
#define DMA_CNT_7 (IO_DMA2_BASE+0x0E)
#define DMA_MODE_READ 0x44 /* I/O to memory, no autoinit, increment, single mode */
#define DMA_MODE_WRITE 0x48 /* memory to I/O, no autoinit, increment, single mode */
#define DMA_MODE_CASCADE 0xC0 /* pass thru DREQ->HRQ, DACK<-HLDA only */
#define DMA_AUTOINIT 0x10
#define DMA_8BIT 0
#define DMA_16BIT 1
#define DMA_BUSMASTER 2
extern spinlock_t dma_spin_lock;
static __inline__ unsigned long claim_dma_lock(void)
{
unsigned long flags;
spin_lock_irqsave(&dma_spin_lock, flags);
return flags;
}
static __inline__ void release_dma_lock(unsigned long flags)
{
spin_unlock_irqrestore(&dma_spin_lock, flags);
}
/* enable/disable a specific DMA channel */
static __inline__ void enable_dma(unsigned int dmanr)
{
if (dmanr<=3)
dma_outb(dmanr, DMA1_MASK_REG);
else
dma_outb(dmanr & 3, DMA2_MASK_REG);
}
static __inline__ void disable_dma(unsigned int dmanr)
{
if (dmanr<=3)
dma_outb(dmanr | 4, DMA1_MASK_REG);
else
dma_outb((dmanr & 3) | 4, DMA2_MASK_REG);
}
/* Clear the 'DMA Pointer Flip Flop'.
* Write 0 for LSB/MSB, 1 for MSB/LSB access.
* Use this once to initialize the FF to a known state.
* After that, keep track of it. :-)
* --- In order to do that, the DMA routines below should ---
* --- only be used while holding the DMA lock ! ---
*/
static __inline__ void clear_dma_ff(unsigned int dmanr)
{
if (dmanr<=3)
dma_outb(0, DMA1_CLEAR_FF_REG);
else
dma_outb(0, DMA2_CLEAR_FF_REG);
}
/* set mode (above) for a specific DMA channel */
static __inline__ void set_dma_mode(unsigned int dmanr, char mode)
{
if (dmanr<=3)
dma_outb(mode | dmanr, DMA1_MODE_REG);
else
dma_outb(mode | (dmanr&3), DMA2_MODE_REG);
}
/* Set transfer address & page bits for specific DMA channel.
* Assumes dma flipflop is clear.
*/
static __inline__ void set_dma_addr(unsigned int dmanr, unsigned int a)
{
if (dmanr <= 3) {
dma_outb( a & 0xff, ((dmanr&3)<<1) + IO_DMA1_BASE );
dma_outb( (a>>8) & 0xff, ((dmanr&3)<<1) + IO_DMA1_BASE );
} else {
dma_outb( (a>>1) & 0xff, ((dmanr&3)<<2) + IO_DMA2_BASE );
dma_outb( (a>>9) & 0xff, ((dmanr&3)<<2) + IO_DMA2_BASE );
}
}
/* Set transfer size (max 64k for DMA1..3, 128k for DMA5..7) for
* a specific DMA channel.
* You must ensure the parameters are valid.
* NOTE: from a manual: "the number of transfers is one more
* than the initial word count"! This is taken into account.
* Assumes dma flip-flop is clear.
* NOTE 2: "count" represents _bytes_ and must be even for channels 5-7.
*/
static __inline__ void set_dma_count(unsigned int dmanr, unsigned int count)
{
count--;
if (dmanr <= 3) {
dma_outb( count & 0xff, ((dmanr&3)<<1) + 1 + IO_DMA1_BASE );
dma_outb( (count>>8) & 0xff, ((dmanr&3)<<1) + 1 + IO_DMA1_BASE );
} else {
dma_outb( (count>>1) & 0xff, ((dmanr&3)<<2) + 2 + IO_DMA2_BASE );
dma_outb( (count>>9) & 0xff, ((dmanr&3)<<2) + 2 + IO_DMA2_BASE );
}
}
/* 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.
*
* Assumes DMA flip-flop is clear.
*/
static __inline__ int get_dma_residue(unsigned int dmanr)
{
unsigned int io_port = (dmanr<=3)? ((dmanr&3)<<1) + 1 + IO_DMA1_BASE
: ((dmanr&3)<<2) + 2 + IO_DMA2_BASE;
/* using short to get 16-bit wrap around */
unsigned short count;
count = 1 + dma_inb(io_port);
count += dma_inb(io_port) << 8;
return (dmanr<=3)? count : (count<<1);
}
/* These are in kernel/dma.c: */
extern int request_dma(unsigned int dmanr, const char * device_id); /* reserve a DMA channel */
extern void free_dma(unsigned int dmanr); /* release it again */
/* These are in arch/m68k/apollo/dma.c: */
extern unsigned short dma_map_page(unsigned long phys_addr,int count,int type);
extern void dma_unmap_page(unsigned short dma_addr);
#endif /* _ASM_APOLLO_DMA_H */
|
