1 | // SPDX-License-Identifier: GPL-2.0-only |
---|---|
2 | /* |
3 | * Minimalist driver for a generic PCI-to-EISA bridge. |
4 | * |
5 | * (C) 2003 Marc Zyngier <maz@wild-wind.fr.eu.org> |
6 | * |
7 | * Ivan Kokshaysky <ink@jurassic.park.msu.ru> : |
8 | * Generalisation from i82375 to PCI_CLASS_BRIDGE_EISA. |
9 | */ |
10 | |
11 | #include <linux/kernel.h> |
12 | #include <linux/device.h> |
13 | #include <linux/eisa.h> |
14 | #include <linux/pci.h> |
15 | #include <linux/module.h> |
16 | #include <linux/init.h> |
17 | |
18 | /* There is only *one* pci_eisa device per machine, right ? */ |
19 | static struct eisa_root_device pci_eisa_root; |
20 | |
21 | static int __init pci_eisa_init(struct pci_dev *pdev) |
22 | { |
23 | struct resource *res, *bus_res = NULL; |
24 | int rc; |
25 | |
26 | if ((rc = pci_enable_device (dev: pdev))) { |
27 | dev_err(&pdev->dev, "Could not enable device\n"); |
28 | return rc; |
29 | } |
30 | |
31 | /* |
32 | * The Intel 82375 PCI-EISA bridge is a subtractive-decode PCI |
33 | * device, so the resources available on EISA are the same as those |
34 | * available on the 82375 bus. This works the same as a PCI-PCI |
35 | * bridge in subtractive-decode mode (see pci_read_bridge_bases()). |
36 | * We assume other PCI-EISA bridges are similar. |
37 | * |
38 | * eisa_root_register() can only deal with a single io port resource, |
39 | * so we use the first valid io port resource. |
40 | */ |
41 | pci_bus_for_each_resource(pdev->bus, res) |
42 | if (res && (res->flags & IORESOURCE_IO)) { |
43 | bus_res = res; |
44 | break; |
45 | } |
46 | |
47 | if (!bus_res) { |
48 | dev_err(&pdev->dev, "No resources available\n"); |
49 | return -1; |
50 | } |
51 | |
52 | pci_eisa_root.dev = &pdev->dev; |
53 | pci_eisa_root.res = bus_res; |
54 | pci_eisa_root.bus_base_addr = bus_res->start; |
55 | pci_eisa_root.slots = EISA_MAX_SLOTS; |
56 | pci_eisa_root.dma_mask = pdev->dma_mask; |
57 | dev_set_drvdata(dev: pci_eisa_root.dev, data: &pci_eisa_root); |
58 | |
59 | if (eisa_root_register (root: &pci_eisa_root)) { |
60 | dev_err(&pdev->dev, "Could not register EISA root\n"); |
61 | return -1; |
62 | } |
63 | |
64 | return 0; |
65 | } |
66 | |
67 | /* |
68 | * We have to call pci_eisa_init_early() before pnpacpi_init()/isapnp_init(). |
69 | * Otherwise pnp resource will get enabled early and could prevent eisa |
70 | * to be initialized. |
71 | * Also need to make sure pci_eisa_init_early() is called after |
72 | * x86/pci_subsys_init(). |
73 | * So need to use subsys_initcall_sync with it. |
74 | */ |
75 | static int __init pci_eisa_init_early(void) |
76 | { |
77 | struct pci_dev *dev = NULL; |
78 | int ret; |
79 | |
80 | for_each_pci_dev(dev) |
81 | if ((dev->class >> 8) == PCI_CLASS_BRIDGE_EISA) { |
82 | ret = pci_eisa_init(pdev: dev); |
83 | if (ret) |
84 | return ret; |
85 | } |
86 | |
87 | return 0; |
88 | } |
89 | subsys_initcall_sync(pci_eisa_init_early); |
90 |