release/src-rt-6.x.4708/linux/linux-2.6.36/arch/ia64/pci/fixup.c

   1 /*
   2  * Exceptions for specific devices. Usually work-arounds for fatal design flaws.
   3  * Derived from fixup.c of i386 tree.
   4  */
   5
   6 #include <linux/pci.h>
   7 #include <linux/init.h>
   8
   9 #include <asm/machvec.h>
  10
  11 /*
  12  * Fixup to mark boot BIOS video selected by BIOS before it changes
  13  *
  14  * From information provided by "Jon Smirl" <jonsmirl@gmail.com>
  15  *
  16  * The standard boot ROM sequence for an x86 machine uses the BIOS
  17  * to select an initial video card for boot display. This boot video
  18  * card will have it's BIOS copied to C0000 in system RAM.
  19  * IORESOURCE_ROM_SHADOW is used to associate the boot video
  20  * card with this copy. On laptops this copy has to be used since
  21  * the main ROM may be compressed or combined with another image.
  22  * See pci_map_rom() for use of this flag. IORESOURCE_ROM_SHADOW
  23  * is marked here since the boot video device will be the only enabled
  24  * video device at this point.
  25  */
  26
  27 static void __devinit pci_fixup_video(struct pci_dev *pdev)
  28 {
  29         struct pci_dev *bridge;
  30         struct pci_bus *bus;
  31         u16 config;
  32
  33         if ((strcmp(platform_name, "dig") != 0)
  34             && (strcmp(platform_name, "hpzx1")  != 0))
  35                 return;
  36         /* Maybe, this machine supports legacy memory map. */
  37
  38         if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
  39                 return;
  40
  41         /* Is VGA routed to us? */
  42         bus = pdev->bus;
  43         while (bus) {
  44                 bridge = bus->self;
  45
  46                 /*
  47                  * From information provided by
  48                  * "David Miller" <davem@davemloft.net>
  49                  * The bridge control register is valid for PCI header
  50                  * type BRIDGE, or CARDBUS. Host to PCI controllers use
  51                  * PCI header type NORMAL.
  52                  */
  53                 if (bridge
  54                     &&((bridge->hdr_type == PCI_HEADER_TYPE_BRIDGE)
  55                        ||(bridge->hdr_type == PCI_HEADER_TYPE_CARDBUS))) {
  56                         pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
  57                                                 &config);
  58                         if (!(config & PCI_BRIDGE_CTL_VGA))
  59                                 return;
  60                 }
  61                 bus = bus->parent;
  62         }
  63         pci_read_config_word(pdev, PCI_COMMAND, &config);
  64         if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
  65                 pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
  66                 dev_printk(KERN_DEBUG, &pdev->dev, "Boot video device\n");
  67         }
  68 }
  69 DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pci_fixup_video);