Merge branches 'release' and 'gpe-ack' into release
[linux-2.6] / arch / arm / kernel / dma-isa.c
1 /*
2  *  linux/arch/arm/kernel/dma-isa.c
3  *
4  *  Copyright (C) 1999-2000 Russell King
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  *  ISA DMA primitives
11  *  Taken from various sources, including:
12  *   linux/include/asm/dma.h: Defines for using and allocating dma channels.
13  *     Written by Hennus Bergman, 1992.
14  *     High DMA channel support & info by Hannu Savolainen and John Boyd,
15  *     Nov. 1992.
16  *   arch/arm/kernel/dma-ebsa285.c
17  *   Copyright (C) 1998 Phil Blundell
18  */
19 #include <linux/ioport.h>
20 #include <linux/init.h>
21 #include <linux/dma-mapping.h>
22
23 #include <asm/dma.h>
24 #include <asm/io.h>
25
26 #include <asm/mach/dma.h>
27
28 #define ISA_DMA_MODE_READ       0x44
29 #define ISA_DMA_MODE_WRITE      0x48
30 #define ISA_DMA_MODE_CASCADE    0xc0
31 #define ISA_DMA_AUTOINIT        0x10
32
33 #define ISA_DMA_MASK            0
34 #define ISA_DMA_MODE            1
35 #define ISA_DMA_CLRFF           2
36 #define ISA_DMA_PGHI            3
37 #define ISA_DMA_PGLO            4
38 #define ISA_DMA_ADDR            5
39 #define ISA_DMA_COUNT           6
40
41 static unsigned int isa_dma_port[8][7] = {
42         /* MASK   MODE   CLRFF  PAGE_HI PAGE_LO ADDR COUNT */
43         {  0x0a,  0x0b,  0x0c,  0x487,  0x087,  0x00, 0x01 },
44         {  0x0a,  0x0b,  0x0c,  0x483,  0x083,  0x02, 0x03 },
45         {  0x0a,  0x0b,  0x0c,  0x481,  0x081,  0x04, 0x05 },
46         {  0x0a,  0x0b,  0x0c,  0x482,  0x082,  0x06, 0x07 },
47         {  0xd4,  0xd6,  0xd8,  0x000,  0x000,  0xc0, 0xc2 },
48         {  0xd4,  0xd6,  0xd8,  0x48b,  0x08b,  0xc4, 0xc6 },
49         {  0xd4,  0xd6,  0xd8,  0x489,  0x089,  0xc8, 0xca },
50         {  0xd4,  0xd6,  0xd8,  0x48a,  0x08a,  0xcc, 0xce }
51 };
52
53 static int isa_get_dma_residue(dmach_t channel, dma_t *dma)
54 {
55         unsigned int io_port = isa_dma_port[channel][ISA_DMA_COUNT];
56         int count;
57
58         count = 1 + inb(io_port);
59         count |= inb(io_port) << 8;
60
61         return channel < 4 ? count : (count << 1);
62 }
63
64 static void isa_enable_dma(dmach_t channel, dma_t *dma)
65 {
66         if (dma->invalid) {
67                 unsigned long address, length;
68                 unsigned int mode;
69                 enum dma_data_direction direction;
70
71                 mode = channel & 3;
72                 switch (dma->dma_mode & DMA_MODE_MASK) {
73                 case DMA_MODE_READ:
74                         mode |= ISA_DMA_MODE_READ;
75                         direction = DMA_FROM_DEVICE;
76                         break;
77
78                 case DMA_MODE_WRITE:
79                         mode |= ISA_DMA_MODE_WRITE;
80                         direction = DMA_TO_DEVICE;
81                         break;
82
83                 case DMA_MODE_CASCADE:
84                         mode |= ISA_DMA_MODE_CASCADE;
85                         direction = DMA_BIDIRECTIONAL;
86                         break;
87
88                 default:
89                         direction = DMA_NONE;
90                         break;
91                 }
92
93                 if (!dma->sg) {
94                         /*
95                          * Cope with ISA-style drivers which expect cache
96                          * coherence.
97                          */
98                         dma->sg = &dma->buf;
99                         dma->sgcount = 1;
100                         dma->buf.length = dma->count;
101                         dma->buf.dma_address = dma_map_single(NULL,
102                                 dma->addr, dma->count,
103                                 direction);
104                 }
105
106                 address = dma->buf.dma_address;
107                 length  = dma->buf.length - 1;
108
109                 outb(address >> 16, isa_dma_port[channel][ISA_DMA_PGLO]);
110                 outb(address >> 24, isa_dma_port[channel][ISA_DMA_PGHI]);
111
112                 if (channel >= 4) {
113                         address >>= 1;
114                         length >>= 1;
115                 }
116
117                 outb(0, isa_dma_port[channel][ISA_DMA_CLRFF]);
118
119                 outb(address, isa_dma_port[channel][ISA_DMA_ADDR]);
120                 outb(address >> 8, isa_dma_port[channel][ISA_DMA_ADDR]);
121
122                 outb(length, isa_dma_port[channel][ISA_DMA_COUNT]);
123                 outb(length >> 8, isa_dma_port[channel][ISA_DMA_COUNT]);
124
125                 if (dma->dma_mode & DMA_AUTOINIT)
126                         mode |= ISA_DMA_AUTOINIT;
127
128                 outb(mode, isa_dma_port[channel][ISA_DMA_MODE]);
129                 dma->invalid = 0;
130         }
131         outb(channel & 3, isa_dma_port[channel][ISA_DMA_MASK]);
132 }
133
134 static void isa_disable_dma(dmach_t channel, dma_t *dma)
135 {
136         outb(channel | 4, isa_dma_port[channel][ISA_DMA_MASK]);
137 }
138
139 static struct dma_ops isa_dma_ops = {
140         .type           = "ISA",
141         .enable         = isa_enable_dma,
142         .disable        = isa_disable_dma,
143         .residue        = isa_get_dma_residue,
144 };
145
146 static struct resource dma_resources[] = { {
147         .name   = "dma1",
148         .start  = 0x0000,
149         .end    = 0x000f
150 }, {
151         .name   = "dma low page",
152         .start  = 0x0080,
153         .end    = 0x008f
154 }, {
155         .name   = "dma2",
156         .start  = 0x00c0,
157         .end    = 0x00df
158 }, {
159         .name   = "dma high page",
160         .start  = 0x0480,
161         .end    = 0x048f
162 } };
163
164 void __init isa_init_dma(dma_t *dma)
165 {
166         /*
167          * Try to autodetect presence of an ISA DMA controller.
168          * We do some minimal initialisation, and check that
169          * channel 0's DMA address registers are writeable.
170          */
171         outb(0xff, 0x0d);
172         outb(0xff, 0xda);
173
174         /*
175          * Write high and low address, and then read them back
176          * in the same order.
177          */
178         outb(0x55, 0x00);
179         outb(0xaa, 0x00);
180
181         if (inb(0) == 0x55 && inb(0) == 0xaa) {
182                 int channel, i;
183
184                 for (channel = 0; channel < 8; channel++) {
185                         dma[channel].d_ops = &isa_dma_ops;
186                         isa_disable_dma(channel, NULL);
187                 }
188
189                 outb(0x40, 0x0b);
190                 outb(0x41, 0x0b);
191                 outb(0x42, 0x0b);
192                 outb(0x43, 0x0b);
193
194                 outb(0xc0, 0xd6);
195                 outb(0x41, 0xd6);
196                 outb(0x42, 0xd6);
197                 outb(0x43, 0xd6);
198
199                 outb(0, 0xd4);
200
201                 outb(0x10, 0x08);
202                 outb(0x10, 0xd0);
203
204                 /*
205                  * Is this correct?  According to my documentation, it
206                  * doesn't appear to be.  It should be:
207                  *  outb(0x3f, 0x40b); outb(0x3f, 0x4d6);
208                  */
209                 outb(0x30, 0x40b);
210                 outb(0x31, 0x40b);
211                 outb(0x32, 0x40b);
212                 outb(0x33, 0x40b);
213                 outb(0x31, 0x4d6);
214                 outb(0x32, 0x4d6);
215                 outb(0x33, 0x4d6);
216
217                 request_dma(DMA_ISA_CASCADE, "cascade");
218
219                 for (i = 0; i < ARRAY_SIZE(dma_resources); i++)
220                         request_resource(&ioport_resource, dma_resources + i);
221         }
222 }