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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/arch/sh/drivers/pci/pci-dreamcast.c
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// SPDX-License-Identifier: GPL-2.0

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/*

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 * PCI support for the Sega Dreamcast

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 *

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 * Copyright (C) 2001, 2002  M. R. Brown

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 * Copyright (C) 2002, 2003  Paul Mundt

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 *

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 * This file originally bore the message (with enclosed-$):

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 *	Id: pci.c,v 1.3 2003/05/04 19:29:46 lethal Exp

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 *	Dreamcast PCI: Supports SEGA Broadband Adaptor only.

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 */

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#include <linux/sched.h>

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#include <linux/kernel.h>

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#include <linux/param.h>

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#include <linux/interrupt.h>

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#include <linux/init.h>

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#include <linux/irq.h>

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#include <linux/pci.h>

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#include <linux/module.h>

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#include <asm/io.h>

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#include <asm/irq.h>

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#include <mach/pci.h>

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static struct resource gapspci_resources[] = {

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	{

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		.name	= "GAPSPCI IO",

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		.start	= GAPSPCI_BBA_CONFIG,

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		.end	= GAPSPCI_BBA_CONFIG + GAPSPCI_BBA_CONFIG_SIZE - 1,

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		.flags	= IORESOURCE_IO,

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	},  {

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		.name	= "GAPSPCI mem",

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		.start	= GAPSPCI_DMA_BASE,

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		.end	= GAPSPCI_DMA_BASE + GAPSPCI_DMA_SIZE - 1,

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		.flags	= IORESOURCE_MEM,

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	},

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};

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static struct pci_channel dreamcast_pci_controller = {

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	.pci_ops	= &gapspci_pci_ops,

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	.resources	= gapspci_resources,

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	.nr_resources	= ARRAY_SIZE(gapspci_resources),

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	.io_offset	= 0x00000000,

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	.mem_offset	= 0x00000000,

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};

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/*

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 * gapspci init

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 */

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static int __init gapspci_init(void)

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{

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	char idbuf[16];

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	int i;

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	/*

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	 * FIXME: All of this wants documenting to some degree,

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	 * even some basic register definitions would be nice.

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	 *

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	 * I haven't seen anything this ugly since.. maple.

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	 */

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	for (i=0; i<16; i++)

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		idbuf[i] = inb(GAPSPCI_REGS+i);

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	if (strncmp(idbuf, "GAPSPCI_BRIDGE_2", 16))

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		return -ENODEV;

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	outl(0x5a14a501, GAPSPCI_REGS+0x18);

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

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		cpu_relax();

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	if (inl(GAPSPCI_REGS+0x18) != 1)

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		return -EINVAL;

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	outl(0x01000000, GAPSPCI_REGS+0x20);

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	outl(0x01000000, GAPSPCI_REGS+0x24);

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	outl(GAPSPCI_DMA_BASE, GAPSPCI_REGS+0x28);

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

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	outl(1, GAPSPCI_REGS+0x14);

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	outl(1, GAPSPCI_REGS+0x34);

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	/* Setting Broadband Adapter */

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	outw(0xf900, GAPSPCI_BBA_CONFIG+0x06);

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	outl(0x00000000, GAPSPCI_BBA_CONFIG+0x30);

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	outb(0x00, GAPSPCI_BBA_CONFIG+0x3c);

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	outb(0xf0, GAPSPCI_BBA_CONFIG+0x0d);

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	outw(0x0006, GAPSPCI_BBA_CONFIG+0x04);

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	outl(0x00002001, GAPSPCI_BBA_CONFIG+0x10);

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	outl(0x01000000, GAPSPCI_BBA_CONFIG+0x14);

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	return register_pci_controller(&dreamcast_pci_controller);

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}

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arch_initcall(gapspci_init);

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