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

   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-mapping.h>
  23
  24 #include <asm/io.h>
  25 #include <asm/irq.h>
  26 #include <mach/pci.h>
  27
  28 static 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 }
  72 DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, gapspci_fixup_resources);
  73
  74 int 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 }