/*
   * Minimalist driver for a generic PCI-to-EISA bridge.
   *
   * (C) 2003 Marc Zyngier <maz@wild-wind.fr.eu.org>
   *
   * This code is released under the GPL version 2.
   *
   * Ivan Kokshaysky <ink@jurassic.park.msu.ru> :
   * Generalisation from i82375 to PCI_CLASS_BRIDGE_EISA.
   */
  
  #include <linux/kernel.h>
  #include <linux/device.h>
  #include <linux/eisa.h>
  #include <linux/pci.h>
  #include <linux/module.h>
  #include <linux/init.h>
  
  /* There is only *one* pci_eisa device per machine, right ? */
  static struct eisa_root_device pci_eisa_root;

  static int __init pci_eisa_init(struct pci_dev *pdev)

  {

  	int rc, i;
  	struct resource *res, *bus_res = NULL;

  
  	if ((rc = pci_enable_device (pdev))) {

  		dev_err(&pdev->dev, "Could not enable device
  ");

  		return rc;
  	}

  	/*
  	 * The Intel 82375 PCI-EISA bridge is a subtractive-decode PCI
  	 * device, so the resources available on EISA are the same as those
  	 * available on the 82375 bus.  This works the same as a PCI-PCI
  	 * bridge in subtractive-decode mode (see pci_read_bridge_bases()).
  	 * We assume other PCI-EISA bridges are similar.
  	 *
  	 * eisa_root_register() can only deal with a single io port resource,
  	*  so we use the first valid io port resource.
  	 */
  	pci_bus_for_each_resource(pdev->bus, res, i)
  		if (res && (res->flags & IORESOURCE_IO)) {
  			bus_res = res;
  			break;
  		}
  
  	if (!bus_res) {
  		dev_err(&pdev->dev, "No resources available
  ");
  		return -1;
  	}

  	pci_eisa_root.dev              = &pdev->dev;

  	pci_eisa_root.res	       = bus_res;
  	pci_eisa_root.bus_base_addr    = bus_res->start;

  	pci_eisa_root.slots	       = EISA_MAX_SLOTS;
  	pci_eisa_root.dma_mask         = pdev->dma_mask;

  	dev_set_drvdata(pci_eisa_root.dev, &pci_eisa_root);

  
  	if (eisa_root_register (&pci_eisa_root)) {

  		dev_err(&pdev->dev, "Could not register EISA root
  ");

  		return -1;
  	}
  
  	return 0;
  }

  /*
   * We have to call pci_eisa_init_early() before pnpacpi_init()/isapnp_init().
   *   Otherwise pnp resource will get enabled early and could prevent eisa
   *   to be initialized.
   * Also need to make sure pci_eisa_init_early() is called after
   * x86/pci_subsys_init().
   * So need to use subsys_initcall_sync with it.
   */
  static int __init pci_eisa_init_early(void)
  {
  	struct pci_dev *dev = NULL;
  	int ret;

  	for_each_pci_dev(dev)
  		if ((dev->class >> 8) == PCI_CLASS_BRIDGE_EISA) {
  			ret = pci_eisa_init(dev);
  			if (ret)
  				return ret;
  		}

  	return 0;

  }

  subsys_initcall_sync(pci_eisa_init_early);