xref: /openbmc/linux/arch/ia64/pci/fixup.c (revision ca79522c)
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 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(ia64_platform_name, "dig") != 0)
34 	    && (strcmp(ia64_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);
70