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ops-dreamcast.c

/*
 * arch/sh/drivers/pci/ops-dreamcast.c
 *
 * PCI operations for the Sega Dreamcast
 *
 * Copyright (C) 2001, 2002  M. R. Brown
 * Copyright (C) 2002, 2003  Paul Mundt
 *
 * This file originally bore the message (with enclosed-$):
 *    Id: pci.c,v 1.3 2003/05/04 19:29:46 lethal Exp
 *    Dreamcast PCI: Supports SEGA Broadband Adaptor only.
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/pci.h>
#include <linux/module.h>

#include <asm/io.h>
#include <asm/irq.h>
#include <mach/pci.h>

static struct resource gapspci_io_resource = {
      .name = "GAPSPCI IO",
      .start      = GAPSPCI_BBA_CONFIG,
      .end  = GAPSPCI_BBA_CONFIG + GAPSPCI_BBA_CONFIG_SIZE - 1,
      .flags      = IORESOURCE_IO,
};

static struct resource gapspci_mem_resource = {
      .name = "GAPSPCI mem",
      .start      = GAPSPCI_DMA_BASE,
      .end  = GAPSPCI_DMA_BASE + GAPSPCI_DMA_SIZE - 1,
      .flags      = IORESOURCE_MEM,
};

static struct pci_ops gapspci_pci_ops;

struct pci_channel board_pci_channels[] = {
      { &gapspci_pci_ops, &gapspci_io_resource,
        &gapspci_mem_resource, 0, 1 },
      { 0, }
};
EXPORT_SYMBOL(board_pci_channels);

/*
 * The !gapspci_config_access case really shouldn't happen, ever, unless
 * someone implicitly messes around with the last devfn value.. otherwise we
 * only support a single device anyways, and if we didn't have a BBA, we
 * wouldn't make it terribly far through the PCI setup anyways.
 *
 * Also, we could very easily support both Type 0 and Type 1 configurations
 * here, but since it doesn't seem that there is any such implementation in
 * existence, we don't bother.
 *
 * I suppose if someone actually gets around to ripping the chip out of
 * the BBA and hanging some more devices off of it, then this might be
 * something to take into consideration. However, due to the cost of the BBA,
 * and the general lack of activity by DC hardware hackers, this doesn't seem
 * likely to happen anytime soon.
 */
static int gapspci_config_access(unsigned char bus, unsigned int devfn)
{
      return (bus == 0) && (devfn == 0);
}

/*
 * We can also actually read and write in b/w/l sizes! Thankfully this part
 * was at least done right, and we don't have to do the stupid masking and
 * shifting that we do on the 7751! Small wonders never cease to amaze.
 */
static int gapspci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val)
{
      *val = 0xffffffff;

      if (!gapspci_config_access(bus->number, devfn))
            return PCIBIOS_DEVICE_NOT_FOUND;

      switch (size) {
            case 1: *val = inb(GAPSPCI_BBA_CONFIG+where); break;
            case 2: *val = inw(GAPSPCI_BBA_CONFIG+where); break;
            case 4: *val = inl(GAPSPCI_BBA_CONFIG+where); break;
      }     

        return PCIBIOS_SUCCESSFUL;
}

static int gapspci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val)
{
      if (!gapspci_config_access(bus->number, devfn))
            return PCIBIOS_DEVICE_NOT_FOUND;

      switch (size) {
            case 1: outb(( u8)val, GAPSPCI_BBA_CONFIG+where); break;
            case 2: outw((u16)val, GAPSPCI_BBA_CONFIG+where); break;
            case 4: outl((u32)val, GAPSPCI_BBA_CONFIG+where); break;
      }

        return PCIBIOS_SUCCESSFUL;
}

static struct pci_ops gapspci_pci_ops = {
      .read = gapspci_read,
      .write      = gapspci_write,
};

/*
 * gapspci init
 */

int __init gapspci_init(void)
{
      char idbuf[16];
      int i;

      /*
       * FIXME: All of this wants documenting to some degree,
       * even some basic register definitions would be nice.
       *
       * I haven't seen anything this ugly since.. maple.
       */

      for (i=0; i<16; i++)
            idbuf[i] = inb(GAPSPCI_REGS+i);

      if (strncmp(idbuf, "GAPSPCI_BRIDGE_2", 16))
            return -ENODEV;

      outl(0x5a14a501, GAPSPCI_REGS+0x18);

      for (i=0; i<1000000; i++)
            ;

      if (inl(GAPSPCI_REGS+0x18) != 1)
            return -EINVAL;

      outl(0x01000000, GAPSPCI_REGS+0x20);
      outl(0x01000000, GAPSPCI_REGS+0x24);

      outl(GAPSPCI_DMA_BASE, GAPSPCI_REGS+0x28);
      outl(GAPSPCI_DMA_BASE+GAPSPCI_DMA_SIZE, GAPSPCI_REGS+0x2c);

      outl(1, GAPSPCI_REGS+0x14);
      outl(1, GAPSPCI_REGS+0x34);

      /* Setting Broadband Adapter */
      outw(0xf900, GAPSPCI_BBA_CONFIG+0x06);
      outl(0x00000000, GAPSPCI_BBA_CONFIG+0x30);
      outb(0x00, GAPSPCI_BBA_CONFIG+0x3c);
      outb(0xf0, GAPSPCI_BBA_CONFIG+0x0d);
      outw(0x0006, GAPSPCI_BBA_CONFIG+0x04);
      outl(0x00002001, GAPSPCI_BBA_CONFIG+0x10);
      outl(0x01000000, GAPSPCI_BBA_CONFIG+0x14);

      return 0;
}

/* Haven't done anything here as yet */
char * __devinit pcibios_setup(char *str)
{
      return str;
}

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