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1 | /* $Id: dma.h,v 1.2 1999/04/27 00:46:18 deller Exp $ |
2 | * linux/include/asm/dma.h: Defines for using and allocating dma channels. | |
3 | * Written by Hennus Bergman, 1992. | |
4 | * High DMA channel support & info by Hannu Savolainen | |
5 | * and John Boyd, Nov. 1992. | |
6 | * (c) Copyright 2000, Grant Grundler | |
7 | */ | |
8 | ||
9 | #ifndef _ASM_DMA_H | |
10 | #define _ASM_DMA_H | |
11 | ||
1da177e4 LT |
12 | #include <asm/io.h> /* need byte IO */ |
13 | #include <asm/system.h> | |
14 | ||
15 | #define dma_outb outb | |
16 | #define dma_inb inb | |
17 | ||
18 | /* | |
19 | ** DMA_CHUNK_SIZE is used by the SCSI mid-layer to break up | |
0779bf2d | 20 | ** (or rather not merge) DMAs into manageable chunks. |
1da177e4 | 21 | ** On parisc, this is more of the software/tuning constraint |
0779bf2d ML |
22 | ** rather than the HW. I/O MMU allocation algorithms can be |
23 | ** faster with smaller sizes (to some degree). | |
1da177e4 LT |
24 | */ |
25 | #define DMA_CHUNK_SIZE (BITS_PER_LONG*PAGE_SIZE) | |
26 | ||
27 | /* The maximum address that we can perform a DMA transfer to on this platform | |
28 | ** New dynamic DMA interfaces should obsolete this.... | |
29 | */ | |
30 | #define MAX_DMA_ADDRESS (~0UL) | |
31 | ||
32 | /* | |
33 | ** We don't have DMA channels... well V-class does but the | |
34 | ** Dynamic DMA Mapping interface will support them... right? :^) | |
35 | ** Note: this is not relevant right now for PA-RISC, but we cannot | |
36 | ** leave this as undefined because some things (e.g. sound) | |
37 | ** won't compile :-( | |
38 | */ | |
39 | #define MAX_DMA_CHANNELS 8 | |
40 | #define DMA_MODE_READ 0x44 /* I/O to memory, no autoinit, increment, single mode */ | |
41 | #define DMA_MODE_WRITE 0x48 /* memory to I/O, no autoinit, increment, single mode */ | |
42 | #define DMA_MODE_CASCADE 0xC0 /* pass thru DREQ->HRQ, DACK<-HLDA only */ | |
43 | ||
44 | #define DMA_AUTOINIT 0x10 | |
45 | ||
46 | /* 8237 DMA controllers */ | |
47 | #define IO_DMA1_BASE 0x00 /* 8 bit slave DMA, channels 0..3 */ | |
48 | #define IO_DMA2_BASE 0xC0 /* 16 bit master DMA, ch 4(=slave input)..7 */ | |
49 | ||
50 | /* DMA controller registers */ | |
51 | #define DMA1_CMD_REG 0x08 /* command register (w) */ | |
52 | #define DMA1_STAT_REG 0x08 /* status register (r) */ | |
53 | #define DMA1_REQ_REG 0x09 /* request register (w) */ | |
54 | #define DMA1_MASK_REG 0x0A /* single-channel mask (w) */ | |
55 | #define DMA1_MODE_REG 0x0B /* mode register (w) */ | |
56 | #define DMA1_CLEAR_FF_REG 0x0C /* clear pointer flip-flop (w) */ | |
57 | #define DMA1_TEMP_REG 0x0D /* Temporary Register (r) */ | |
58 | #define DMA1_RESET_REG 0x0D /* Master Clear (w) */ | |
59 | #define DMA1_CLR_MASK_REG 0x0E /* Clear Mask */ | |
60 | #define DMA1_MASK_ALL_REG 0x0F /* all-channels mask (w) */ | |
61 | #define DMA1_EXT_MODE_REG (0x400 | DMA1_MODE_REG) | |
62 | ||
63 | #define DMA2_CMD_REG 0xD0 /* command register (w) */ | |
64 | #define DMA2_STAT_REG 0xD0 /* status register (r) */ | |
65 | #define DMA2_REQ_REG 0xD2 /* request register (w) */ | |
66 | #define DMA2_MASK_REG 0xD4 /* single-channel mask (w) */ | |
67 | #define DMA2_MODE_REG 0xD6 /* mode register (w) */ | |
68 | #define DMA2_CLEAR_FF_REG 0xD8 /* clear pointer flip-flop (w) */ | |
69 | #define DMA2_TEMP_REG 0xDA /* Temporary Register (r) */ | |
70 | #define DMA2_RESET_REG 0xDA /* Master Clear (w) */ | |
71 | #define DMA2_CLR_MASK_REG 0xDC /* Clear Mask */ | |
72 | #define DMA2_MASK_ALL_REG 0xDE /* all-channels mask (w) */ | |
73 | #define DMA2_EXT_MODE_REG (0x400 | DMA2_MODE_REG) | |
74 | ||
1da177e4 LT |
75 | static __inline__ unsigned long claim_dma_lock(void) |
76 | { | |
99b6e9be | 77 | return 0; |
1da177e4 LT |
78 | } |
79 | ||
80 | static __inline__ void release_dma_lock(unsigned long flags) | |
81 | { | |
1da177e4 LT |
82 | } |
83 | ||
84 | ||
85 | /* Get DMA residue count. After a DMA transfer, this | |
86 | * should return zero. Reading this while a DMA transfer is | |
87 | * still in progress will return unpredictable results. | |
88 | * If called before the channel has been used, it may return 1. | |
89 | * Otherwise, it returns the number of _bytes_ left to transfer. | |
90 | * | |
91 | * Assumes DMA flip-flop is clear. | |
92 | */ | |
93 | static __inline__ int get_dma_residue(unsigned int dmanr) | |
94 | { | |
95 | unsigned int io_port = (dmanr<=3)? ((dmanr&3)<<1) + 1 + IO_DMA1_BASE | |
96 | : ((dmanr&3)<<2) + 2 + IO_DMA2_BASE; | |
97 | ||
98 | /* using short to get 16-bit wrap around */ | |
99 | unsigned short count; | |
100 | ||
101 | count = 1 + dma_inb(io_port); | |
102 | count += dma_inb(io_port) << 8; | |
103 | ||
104 | return (dmanr<=3)? count : (count<<1); | |
105 | } | |
106 | ||
107 | /* enable/disable a specific DMA channel */ | |
108 | static __inline__ void enable_dma(unsigned int dmanr) | |
109 | { | |
110 | #ifdef CONFIG_SUPERIO | |
111 | if (dmanr<=3) | |
112 | dma_outb(dmanr, DMA1_MASK_REG); | |
113 | else | |
114 | dma_outb(dmanr & 3, DMA2_MASK_REG); | |
115 | #endif | |
116 | } | |
117 | ||
118 | static __inline__ void disable_dma(unsigned int dmanr) | |
119 | { | |
120 | #ifdef CONFIG_SUPERIO | |
121 | if (dmanr<=3) | |
122 | dma_outb(dmanr | 4, DMA1_MASK_REG); | |
123 | else | |
124 | dma_outb((dmanr & 3) | 4, DMA2_MASK_REG); | |
125 | #endif | |
126 | } | |
127 | ||
128 | /* reserve a DMA channel */ | |
129 | #define request_dma(dmanr, device_id) (0) | |
130 | ||
131 | /* Clear the 'DMA Pointer Flip Flop'. | |
132 | * Write 0 for LSB/MSB, 1 for MSB/LSB access. | |
133 | * Use this once to initialize the FF to a known state. | |
134 | * After that, keep track of it. :-) | |
135 | * --- In order to do that, the DMA routines below should --- | |
136 | * --- only be used while holding the DMA lock ! --- | |
137 | */ | |
138 | static __inline__ void clear_dma_ff(unsigned int dmanr) | |
139 | { | |
140 | } | |
141 | ||
142 | /* set mode (above) for a specific DMA channel */ | |
143 | static __inline__ void set_dma_mode(unsigned int dmanr, char mode) | |
144 | { | |
145 | } | |
146 | ||
147 | /* Set only the page register bits of the transfer address. | |
148 | * This is used for successive transfers when we know the contents of | |
149 | * the lower 16 bits of the DMA current address register, but a 64k boundary | |
150 | * may have been crossed. | |
151 | */ | |
152 | static __inline__ void set_dma_page(unsigned int dmanr, char pagenr) | |
153 | { | |
154 | } | |
155 | ||
156 | ||
157 | /* Set transfer address & page bits for specific DMA channel. | |
158 | * Assumes dma flipflop is clear. | |
159 | */ | |
160 | static __inline__ void set_dma_addr(unsigned int dmanr, unsigned int a) | |
161 | { | |
162 | } | |
163 | ||
164 | ||
165 | /* Set transfer size (max 64k for DMA1..3, 128k for DMA5..7) for | |
166 | * a specific DMA channel. | |
167 | * You must ensure the parameters are valid. | |
168 | * NOTE: from a manual: "the number of transfers is one more | |
169 | * than the initial word count"! This is taken into account. | |
170 | * Assumes dma flip-flop is clear. | |
171 | * NOTE 2: "count" represents _bytes_ and must be even for channels 5-7. | |
172 | */ | |
173 | static __inline__ void set_dma_count(unsigned int dmanr, unsigned int count) | |
174 | { | |
175 | } | |
176 | ||
177 | ||
178 | #define free_dma(dmanr) | |
179 | ||
180 | #ifdef CONFIG_PCI | |
181 | extern int isa_dma_bridge_buggy; | |
182 | #else | |
183 | #define isa_dma_bridge_buggy (0) | |
184 | #endif | |
185 | ||
186 | #endif /* _ASM_DMA_H */ |