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 (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(pci_eisa_root.dev, &pci_eisa_root); 58 59 if (eisa_root_register (&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(dev); 83 if (ret) 84 return ret; 85 } 86 87 return 0; 88 } 89 subsys_initcall_sync(pci_eisa_init_early); 90