arch/sh/drivers/pci/ops-dreamcast.c

   1 /*
   2  * arch/sh/drivers/pci/ops-dreamcast.c
   3  *
   4  * PCI operations for the Sega Dreamcast
   5  *
   6  * Copyright (C) 2001, 2002  M. R. Brown
   7  * Copyright (C) 2002, 2003  Paul Mundt
   8  *
   9  * This file originally bore the message (with enclosed-$):
  10  *      Id: pci.c,v 1.3 2003/05/04 19:29:46 lethal Exp
  11  *      Dreamcast PCI: Supports SEGA Broadband Adaptor only.
  12  *
  13  * This file is subject to the terms and conditions of the GNU General Public
  14  * License.  See the file "COPYING" in the main directory of this archive
  15  * for more details.
  16  */
  17
  18 #include <linux/sched.h>
  19 #include <linux/kernel.h>
  20 #include <linux/param.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/init.h>
  23 #include <linux/irq.h>
  24 #include <linux/pci.h>
  25
  26 #include <asm/io.h>
  27 #include <asm/irq.h>
  28 #include <asm/mach/pci.h>
  29
  30 static struct resource gapspci_io_resource = {
  31         .name   = "GAPSPCI IO",
  32         .start  = GAPSPCI_BBA_CONFIG,
  33         .end    = GAPSPCI_BBA_CONFIG + GAPSPCI_BBA_CONFIG_SIZE - 1,
  34         .flags  = IORESOURCE_IO,
  35 };
  36
  37 static struct resource gapspci_mem_resource = {
  38         .name   = "GAPSPCI mem",
  39         .start  = GAPSPCI_DMA_BASE,
  40         .end    = GAPSPCI_DMA_BASE + GAPSPCI_DMA_SIZE - 1,
  41         .flags  = IORESOURCE_MEM,
  42 };
  43
  44 static struct pci_ops gapspci_pci_ops;
  45
  46 struct pci_channel board_pci_channels[] = {
  47         { &gapspci_pci_ops, &gapspci_io_resource,
  48           &gapspci_mem_resource, 0, 1 },
  49         { 0, }
  50 };
  51
  52 /*
  53  * The !gapspci_config_access case really shouldn't happen, ever, unless
  54  * someone implicitly messes around with the last devfn value.. otherwise we
  55  * only support a single device anyways, and if we didn't have a BBA, we
  56  * wouldn't make it terribly far through the PCI setup anyways.
  57  *
  58  * Also, we could very easily support both Type 0 and Type 1 configurations
  59  * here, but since it doesn't seem that there is any such implementation in
  60  * existence, we don't bother.
  61  *
  62  * I suppose if someone actually gets around to ripping the chip out of
  63  * the BBA and hanging some more devices off of it, then this might be
  64  * something to take into consideration. However, due to the cost of the BBA,
  65  * and the general lack of activity by DC hardware hackers, this doesn't seem
  66  * likely to happen anytime soon.
  67  */
  68 static int gapspci_config_access(unsigned char bus, unsigned int devfn)
  69 {
  70         return (bus == 0) && (devfn == 0);
  71 }
  72
  73 /*
  74  * We can also actually read and write in b/w/l sizes! Thankfully this part
  75  * was at least done right, and we don't have to do the stupid masking and
  76  * shifting that we do on the 7751! Small wonders never cease to amaze.
  77  */
  78 static int gapspci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val)
  79 {
  80         *val = 0xffffffff;
  81
  82         if (!gapspci_config_access(bus->number, devfn))
  83                 return PCIBIOS_DEVICE_NOT_FOUND;
  84
  85         switch (size) {
  86                 case 1: *val = inb(GAPSPCI_BBA_CONFIG+where); break;
  87                 case 2: *val = inw(GAPSPCI_BBA_CONFIG+where); break;
  88                 case 4: *val = inl(GAPSPCI_BBA_CONFIG+where); break;
  89         }
  90
  91         return PCIBIOS_SUCCESSFUL;
  92 }
  93
  94 static int gapspci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val)
  95 {
  96         if (!gapspci_config_access(bus->number, devfn))
  97                 return PCIBIOS_DEVICE_NOT_FOUND;
  98
  99         switch (size) {
 100                 case 1: outb(( u8)val, GAPSPCI_BBA_CONFIG+where); break;
 101                 case 2: outw((u16)val, GAPSPCI_BBA_CONFIG+where); break;
 102                 case 4: outl((u32)val, GAPSPCI_BBA_CONFIG+where); break;
 103         }
 104
 105         return PCIBIOS_SUCCESSFUL;
 106 }
 107
 108 static struct pci_ops gapspci_pci_ops = {
 109         .read   = gapspci_read,
 110         .write  = gapspci_write,
 111 };
 112
 113 /*
 114  * gapspci init
 115  */
 116
 117 int __init gapspci_init(void)
 118 {
 119         char idbuf[16];
 120         int i;
 121
 122         /*
 123          * FIXME: All of this wants documenting to some degree,
 124          * even some basic register definitions would be nice.
 125          *
 126          * I haven't seen anything this ugly since.. maple.
 127          */
 128
 129         for (i=0; i<16; i++)
 130                 idbuf[i] = inb(GAPSPCI_REGS+i);
 131
 132         if (strncmp(idbuf, "GAPSPCI_BRIDGE_2", 16))
 133                 return -ENODEV;
 134
 135         outl(0x5a14a501, GAPSPCI_REGS+0x18);
 136
 137         for (i=0; i<1000000; i++)
 138                 ;
 139
 140         if (inl(GAPSPCI_REGS+0x18) != 1)
 141                 return -EINVAL;
 142
 143         outl(0x01000000, GAPSPCI_REGS+0x20);
 144         outl(0x01000000, GAPSPCI_REGS+0x24);
 145
 146         outl(GAPSPCI_DMA_BASE, GAPSPCI_REGS+0x28);
 147         outl(GAPSPCI_DMA_BASE+GAPSPCI_DMA_SIZE, GAPSPCI_REGS+0x2c);
 148
 149         outl(1, GAPSPCI_REGS+0x14);
 150         outl(1, GAPSPCI_REGS+0x34);
 151
 152         /* Setting Broadband Adapter */
 153         outw(0xf900, GAPSPCI_BBA_CONFIG+0x06);
 154         outl(0x00000000, GAPSPCI_BBA_CONFIG+0x30);
 155         outb(0x00, GAPSPCI_BBA_CONFIG+0x3c);
 156         outb(0xf0, GAPSPCI_BBA_CONFIG+0x0d);
 157         outw(0x0006, GAPSPCI_BBA_CONFIG+0x04);
 158         outl(0x00002001, GAPSPCI_BBA_CONFIG+0x10);
 159         outl(0x01000000, GAPSPCI_BBA_CONFIG+0x14);
 160
 161         return 0;
 162 }
 163
 164 /* Haven't done anything here as yet */
 165 char * __devinit pcibios_setup(char *str)
 166 {
 167         return str;
 168 }