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

   1 /*
   2  * arch/sh/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/config.h>
  19 #include <linux/sched.h>
  20 #include <linux/kernel.h>
  21 #include <linux/param.h>
  22 #include <linux/interrupt.h>
  23 #include <linux/init.h>
  24 #include <linux/irq.h>
  25 #include <linux/pci.h>
  26
  27 #include <asm/io.h>
  28 #include <asm/irq.h>
  29 #include <asm/mach/pci.h>
  30
  31 static struct resource gapspci_io_resource = {
  32         .name   = "GAPSPCI IO",
  33         .start  = GAPSPCI_BBA_CONFIG,
  34         .end    = GAPSPCI_BBA_CONFIG + GAPSPCI_BBA_CONFIG_SIZE - 1,
  35         .flags  = IORESOURCE_IO,
  36 };
  37
  38 static struct resource gapspci_mem_resource = {
  39         .name   = "GAPSPCI mem",
  40         .start  = GAPSPCI_DMA_BASE,
  41         .end    = GAPSPCI_DMA_BASE + GAPSPCI_DMA_SIZE - 1,
  42         .flags  = IORESOURCE_MEM,
  43 };
  44
  45 static struct pci_ops gapspci_pci_ops;
  46
  47 struct pci_channel board_pci_channels[] = {
  48         { &gapspci_pci_ops, &gapspci_io_resource,
  49           &gapspci_mem_resource, 0, 1 },
  50         { 0, }
  51 };
  52
  53 /*
  54  * The !gapspci_config_access case really shouldn't happen, ever, unless
  55  * someone implicitly messes around with the last devfn value.. otherwise we
  56  * only support a single device anyways, and if we didn't have a BBA, we
  57  * wouldn't make it terribly far through the PCI setup anyways.
  58  *
  59  * Also, we could very easily support both Type 0 and Type 1 configurations
  60  * here, but since it doesn't seem that there is any such implementation in
  61  * existance, we don't bother.
  62  *
  63  * I suppose if someone actually gets around to ripping the chip out of
  64  * the BBA and hanging some more devices off of it, then this might be
  65  * something to take into consideration. However, due to the cost of the BBA,
  66  * and the general lack of activity by DC hardware hackers, this doesn't seem
  67  * likely to happen anytime soon.
  68  */
  69 static int gapspci_config_access(unsigned char bus, unsigned int devfn)
  70 {
  71         return (bus == 0) && (devfn == 0);
  72 }
  73
  74 /*
  75  * We can also actually read and write in b/w/l sizes! Thankfully this part
  76  * was at least done right, and we don't have to do the stupid masking and
  77  * shifting that we do on the 7751! Small wonders never cease to amaze.
  78  */
  79 static int gapspci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val)
  80 {
  81         *val = 0xffffffff;
  82
  83         if (!gapspci_config_access(bus->number, devfn))
  84                 return PCIBIOS_DEVICE_NOT_FOUND;
  85
  86         switch (size) {
  87                 case 1: *val = inb(GAPSPCI_BBA_CONFIG+where); break;
  88                 case 2: *val = inw(GAPSPCI_BBA_CONFIG+where); break;
  89                 case 4: *val = inl(GAPSPCI_BBA_CONFIG+where); break;
  90         }
  91
  92         return PCIBIOS_SUCCESSFUL;
  93 }
  94
  95 static int gapspci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val)
  96 {
  97         if (!gapspci_config_access(bus->number, devfn))
  98                 return PCIBIOS_DEVICE_NOT_FOUND;
  99
 100         switch (size) {
 101                 case 1: outb(( u8)val, GAPSPCI_BBA_CONFIG+where); break;
 102                 case 2: outw((u16)val, GAPSPCI_BBA_CONFIG+where); break;
 103                 case 4: outl((u32)val, GAPSPCI_BBA_CONFIG+where); break;
 104         }
 105
 106         return PCIBIOS_SUCCESSFUL;
 107 }
 108
 109 static struct pci_ops gapspci_pci_ops = {
 110         .read   = gapspci_read,
 111         .write  = gapspci_write,
 112 };
 113
 114 /*
 115  * gapspci init
 116  */
 117
 118 int __init gapspci_init(void)
 119 {
 120         char idbuf[16];
 121         int i;
 122
 123         /*
 124          * FIXME: All of this wants documenting to some degree,
 125          * even some basic register definitions would be nice.
 126          *
 127          * I haven't seen anything this ugly since.. maple.
 128          */
 129
 130         for (i=0; i<16; i++)
 131                 idbuf[i] = inb(GAPSPCI_REGS+i);
 132
 133         if (strncmp(idbuf, "GAPSPCI_BRIDGE_2", 16))
 134                 return -ENODEV;
 135
 136         outl(0x5a14a501, GAPSPCI_REGS+0x18);
 137
 138         for (i=0; i<1000000; i++)
 139                 ;
 140
 141         if (inl(GAPSPCI_REGS+0x18) != 1)
 142                 return -EINVAL;
 143
 144         outl(0x01000000, GAPSPCI_REGS+0x20);
 145         outl(0x01000000, GAPSPCI_REGS+0x24);
 146
 147         outl(GAPSPCI_DMA_BASE, GAPSPCI_REGS+0x28);
 148         outl(GAPSPCI_DMA_BASE+GAPSPCI_DMA_SIZE, GAPSPCI_REGS+0x2c);
 149
 150         outl(1, GAPSPCI_REGS+0x14);
 151         outl(1, GAPSPCI_REGS+0x34);
 152
 153         /* Setting Broadband Adapter */
 154         outw(0xf900, GAPSPCI_BBA_CONFIG+0x06);
 155         outl(0x00000000, GAPSPCI_BBA_CONFIG+0x30);
 156         outb(0x00, GAPSPCI_BBA_CONFIG+0x3c);
 157         outb(0xf0, GAPSPCI_BBA_CONFIG+0x0d);
 158         outw(0x0006, GAPSPCI_BBA_CONFIG+0x04);
 159         outl(0x00002001, GAPSPCI_BBA_CONFIG+0x10);
 160         outl(0x01000000, GAPSPCI_BBA_CONFIG+0x14);
 161
 162         return 0;
 163 }
 164
 165 /* Haven't done anything here as yet */
 166 char * __devinit pcibios_setup(char *str)
 167 {
 168         return str;
 169 }