1/*
2 * Minimalist driver for a generic PCI-to-EISA bridge.
3 *
4 * (C) 2003 Marc Zyngier <maz@wild-wind.fr.eu.org>
5 *
6 * This code is released under the GPL version 2.
7 *
8 * Ivan Kokshaysky <ink@jurassic.park.msu.ru> :
9 * Generalisation from i82375 to PCI_CLASS_BRIDGE_EISA.
10 */
11
12#include <linux/kernel.h>
13#include <linux/device.h>
14#include <linux/eisa.h>
15#include <linux/pci.h>
16#include <linux/module.h>
17#include <linux/init.h>
18
19/* There is only *one* pci_eisa device per machine, right ? */
20static struct eisa_root_device pci_eisa_root;
21
22static int __init pci_eisa_init(struct pci_dev *pdev)
23{
24	int rc, i;
25	struct resource *res, *bus_res = NULL;
26
27	if ((rc = pci_enable_device (pdev))) {
28		dev_err(&pdev->dev, "Could not enable device\n");
29		return rc;
30	}
31
32	/*
33	 * The Intel 82375 PCI-EISA bridge is a subtractive-decode PCI
34	 * device, so the resources available on EISA are the same as those
35	 * available on the 82375 bus.  This works the same as a PCI-PCI
36	 * bridge in subtractive-decode mode (see pci_read_bridge_bases()).
37	 * We assume other PCI-EISA bridges are similar.
38	 *
39	 * eisa_root_register() can only deal with a single io port resource,
40	*  so we use the first valid io port resource.
41	 */
42	pci_bus_for_each_resource(pdev->bus, res, i)
43		if (res && (res->flags & IORESOURCE_IO)) {
44			bus_res = res;
45			break;
46		}
47
48	if (!bus_res) {
49		dev_err(&pdev->dev, "No resources available\n");
50		return -1;
51	}
52
53	pci_eisa_root.dev              = &pdev->dev;
54	pci_eisa_root.res	       = bus_res;
55	pci_eisa_root.bus_base_addr    = bus_res->start;
56	pci_eisa_root.slots	       = EISA_MAX_SLOTS;
57	pci_eisa_root.dma_mask         = pdev->dma_mask;
58	dev_set_drvdata(pci_eisa_root.dev, &pci_eisa_root);
59
60	if (eisa_root_register (&pci_eisa_root)) {
61		dev_err(&pdev->dev, "Could not register EISA root\n");
62		return -1;
63	}
64
65	return 0;
66}
67
68/*
69 * We have to call pci_eisa_init_early() before pnpacpi_init()/isapnp_init().
70 *   Otherwise pnp resource will get enabled early and could prevent eisa
71 *   to be initialized.
72 * Also need to make sure pci_eisa_init_early() is called after
73 * x86/pci_subsys_init().
74 * So need to use subsys_initcall_sync with it.
75 */
76static int __init pci_eisa_init_early(void)
77{
78	struct pci_dev *dev = NULL;
79	int ret;
80
81	for_each_pci_dev(dev)
82		if ((dev->class >> 8) == PCI_CLASS_BRIDGE_EISA) {
83			ret = pci_eisa_init(dev);
84			if (ret)
85				return ret;
86		}
87
88	return 0;
89}
90subsys_initcall_sync(pci_eisa_init_early);
91