// SPDX-License-Identifier: GPL-2.0
/*
 * PCI support 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.
 */

#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_resources[] = {
        {
                .name   = "GAPSPCI IO",
                .start  = GAPSPCI_BBA_CONFIG,
                .end    = GAPSPCI_BBA_CONFIG + GAPSPCI_BBA_CONFIG_SIZE - 1,
                .flags  = IORESOURCE_IO,
        },  {
                .name   = "GAPSPCI mem",
                .start  = GAPSPCI_DMA_BASE,
                .end    = GAPSPCI_DMA_BASE + GAPSPCI_DMA_SIZE - 1,
                .flags  = IORESOURCE_MEM,
        },
};

static struct pci_channel dreamcast_pci_controller = {
        .pci_ops        = &gapspci_pci_ops,
        .resources      = gapspci_resources,
        .nr_resources   = ARRAY_SIZE(gapspci_resources),
        .io_offset      = 0x00000000,
        .mem_offset     = 0x00000000,
};

/*
 * gapspci init
 */

static 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++)
                cpu_relax();

        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 register_pci_controller(&dreamcast_pci_controller);
}
arch_initcall(gapspci_init);