1// SPDX-License-Identifier: GPL-2.0
2/*
3 * arch/sh/drivers/pci/fixups-dreamcast.c
4 *
5 * PCI fixups for the Sega Dreamcast
6 *
7 * Copyright (C) 2001, 2002  M. R. Brown
8 * Copyright (C) 2002, 2003, 2006  Paul Mundt
9 *
10 * This file originally bore the message (with enclosed-$):
11 *	Id: pci.c,v 1.3 2003/05/04 19:29:46 lethal Exp
12 *	Dreamcast PCI: Supports SEGA Broadband Adaptor only.
13 */
14
15#include <linux/sched.h>
16#include <linux/kernel.h>
17#include <linux/param.h>
18#include <linux/interrupt.h>
19#include <linux/init.h>
20#include <linux/irq.h>
21#include <linux/pci.h>
22#include <linux/dma-map-ops.h>
23
24#include <asm/io.h>
25#include <asm/irq.h>
26#include <mach/pci.h>
27
28static void gapspci_fixup_resources(struct pci_dev *dev)
29{
30	struct pci_channel *p = dev->sysdata;
31	struct resource res;
32	struct pci_bus_region region;
33
34	printk(KERN_NOTICE "PCI: Fixing up device %s\n", pci_name(dev));
35
36	switch (dev->device) {
37	case PCI_DEVICE_ID_SEGA_BBA:
38		/*
39		 * We also assume that dev->devfn == 0
40		 */
41		dev->resource[1].start	= p->resources[0].start  + 0x100;
42		dev->resource[1].end	= dev->resource[1].start + 0x200 - 1;
43
44		/*
45		 * This is not a normal BAR, prevent any attempts to move
46		 * the BAR, as this will result in a bus lock.
47		 */
48		dev->resource[1].flags |= IORESOURCE_PCI_FIXED;
49
50		/*
51		 * Redirect dma memory allocations to special memory window.
52		 *
53		 * If this GAPSPCI region were mapped by a BAR, the CPU
54		 * phys_addr_t would be pci_resource_start(), and the bus
55		 * address would be pci_bus_address(pci_resource_start()).
56		 * But apparently there's no BAR mapping it, so we just
57		 * "know" its CPU address is GAPSPCI_DMA_BASE.
58		 */
59		res.start = GAPSPCI_DMA_BASE;
60		res.end = GAPSPCI_DMA_BASE + GAPSPCI_DMA_SIZE - 1;
61		res.flags = IORESOURCE_MEM;
62		pcibios_resource_to_bus(dev->bus, &region, &res);
63		BUG_ON(dma_declare_coherent_memory(&dev->dev,
64						res.start,
65						region.start,
66						resource_size(&res)));
67		break;
68	default:
69		printk("PCI: Failed resource fixup\n");
70	}
71}
72DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, gapspci_fixup_resources);
73
74int pcibios_map_platform_irq(const struct pci_dev *dev, u8 slot, u8 pin)
75{
76	/*
77	 * The interrupt routing semantics here are quite trivial.
78	 *
79	 * We basically only support one interrupt, so we only bother
80	 * updating a device's interrupt line with this single shared
81	 * interrupt. Keeps routing quite simple, doesn't it?
82	 */
83	return GAPSPCI_IRQ;
84}
85