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/pci.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, direction;
  69
  70                 mode = channel & 3;
  71                 switch (dma->dma_mode & DMA_MODE_MASK) {
  72                 case DMA_MODE_READ:
  73                         mode |= ISA_DMA_MODE_READ;
  74                         direction = PCI_DMA_FROMDEVICE;
  75                         break;
  76
  77                 case DMA_MODE_WRITE:
  78                         mode |= ISA_DMA_MODE_WRITE;
  79                         direction = PCI_DMA_TODEVICE;
  80                         break;
  81
  82                 case DMA_MODE_CASCADE:
  83                         mode |= ISA_DMA_MODE_CASCADE;
  84                         direction = PCI_DMA_BIDIRECTIONAL;
  85                         break;
  86
  87                 default:
  88                         direction = PCI_DMA_NONE;
  89                         break;
  90                 }
  91
  92                 if (!dma->using_sg) {
  93                         /*
  94                          * Cope with ISA-style drivers which expect cache
  95                          * coherence.
  96                          */
  97                         dma->buf.dma_address = pci_map_single(NULL,
  98                                 dma->buf.__address, dma->buf.length,
  99                                 direction);
 100                 }
 101
 102                 address = dma->buf.dma_address;
 103                 length  = dma->buf.length - 1;
 104
 105                 outb(address >> 16, isa_dma_port[channel][ISA_DMA_PGLO]);
 106                 outb(address >> 24, isa_dma_port[channel][ISA_DMA_PGHI]);
 107
 108                 if (channel >= 4) {
 109                         address >>= 1;
 110                         length >>= 1;
 111                 }
 112
 113                 outb(0, isa_dma_port[channel][ISA_DMA_CLRFF]);
 114
 115                 outb(address, isa_dma_port[channel][ISA_DMA_ADDR]);
 116                 outb(address >> 8, isa_dma_port[channel][ISA_DMA_ADDR]);
 117
 118                 outb(length, isa_dma_port[channel][ISA_DMA_COUNT]);
 119                 outb(length >> 8, isa_dma_port[channel][ISA_DMA_COUNT]);
 120
 121                 if (dma->dma_mode & DMA_AUTOINIT)
 122                         mode |= ISA_DMA_AUTOINIT;
 123
 124                 outb(mode, isa_dma_port[channel][ISA_DMA_MODE]);
 125                 dma->invalid = 0;
 126         }
 127         outb(channel & 3, isa_dma_port[channel][ISA_DMA_MASK]);
 128 }
 129
 130 static void isa_disable_dma(dmach_t channel, dma_t *dma)
 131 {
 132         outb(channel | 4, isa_dma_port[channel][ISA_DMA_MASK]);
 133 }
 134
 135 static struct dma_ops isa_dma_ops = {
 136         .type           = "ISA",
 137         .enable         = isa_enable_dma,
 138         .disable        = isa_disable_dma,
 139         .residue        = isa_get_dma_residue,
 140 };
 141
 142 static struct resource dma_resources[] = {
 143         { "dma1",               0x0000, 0x000f },
 144         { "dma low page",       0x0080, 0x008f },
 145         { "dma2",               0x00c0, 0x00df },
 146         { "dma high page",      0x0480, 0x048f }
 147 };
 148
 149 void __init isa_init_dma(dma_t *dma)
 150 {
 151         /*
 152          * Try to autodetect presence of an ISA DMA controller.
 153          * We do some minimal initialisation, and check that
 154          * channel 0's DMA address registers are writeable.
 155          */
 156         outb(0xff, 0x0d);
 157         outb(0xff, 0xda);
 158
 159         /*
 160          * Write high and low address, and then read them back
 161          * in the same order.
 162          */
 163         outb(0x55, 0x00);
 164         outb(0xaa, 0x00);
 165
 166         if (inb(0) == 0x55 && inb(0) == 0xaa) {
 167                 int channel, i;
 168
 169                 for (channel = 0; channel < 8; channel++) {
 170                         dma[channel].d_ops = &isa_dma_ops;
 171                         isa_disable_dma(channel, NULL);
 172                 }
 173
 174                 outb(0x40, 0x0b);
 175                 outb(0x41, 0x0b);
 176                 outb(0x42, 0x0b);
 177                 outb(0x43, 0x0b);
 178
 179                 outb(0xc0, 0xd6);
 180                 outb(0x41, 0xd6);
 181                 outb(0x42, 0xd6);
 182                 outb(0x43, 0xd6);
 183
 184                 outb(0, 0xd4);
 185
 186                 outb(0x10, 0x08);
 187                 outb(0x10, 0xd0);
 188
 189                 /*
 190                  * Is this correct?  According to my documentation, it
 191                  * doesn't appear to be.  It should be:
 192                  *  outb(0x3f, 0x40b); outb(0x3f, 0x4d6);
 193                  */
 194                 outb(0x30, 0x40b);
 195                 outb(0x31, 0x40b);
 196                 outb(0x32, 0x40b);
 197                 outb(0x33, 0x40b);
 198                 outb(0x31, 0x4d6);
 199                 outb(0x32, 0x4d6);
 200                 outb(0x33, 0x4d6);
 201
 202                 request_dma(DMA_ISA_CASCADE, "cascade");
 203
 204                 for (i = 0; i < sizeof(dma_resources) / sizeof(dma_resources[0]); i++)
 205                         request_resource(&ioport_resource, dma_resources + i);
 206         }
 207 }