drivers/eisa/pci_eisa.c

   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 ? */
  20 static struct eisa_root_device pci_eisa_root;
  21
  22 static 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  */
  76 static 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 }
  90 subsys_initcall_sync(pci_eisa_init_early);