text: /*
   * Generic PCI host driver common code
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
   *
   * Copyright (C) 2014 ARM Limited
   *
   * Author: Will Deacon <will.deacon@arm.com>
   */
  
  #include <linux/kernel.h>
  #include <linux/of_address.h>
  #include <linux/of_pci.h>
  #include <linux/pci-ecam.h>
  #include <linux/platform_device.h>
  
  static int gen_pci_parse_request_of_pci_ranges(struct device *dev,
  		       struct list_head *resources, struct resource **bus_range)
  {
  	int err, res_valid = 0;
  	struct device_node *np = dev->of_node;
  	resource_size_t iobase;
  	struct resource_entry *win, *tmp;
  
  	err = of_pci_get_host_bridge_resources(np, 0, 0xff, resources, &iobase);
  	if (err)
  		return err;
  
  	err = devm_request_pci_bus_resources(dev, resources);
  	if (err)
  		return err;
  
  	resource_list_for_each_entry_safe(win, tmp, resources) {
  		struct resource *res = win->res;
  
  		switch (resource_type(res)) {
  		case IORESOURCE_IO:
  			err = pci_remap_iospace(res, iobase);
  			if (err) {
  				dev_warn(dev, "error %d: failed to map resource %pR\n",
  					 err, res);
  				resource_list_destroy_entry(win);
  			}
  			break;
  		case IORESOURCE_MEM:
  			res_valid |= !(res->flags & IORESOURCE_PREFETCH);
  			break;
  		case IORESOURCE_BUS:
  			*bus_range = res;
  			break;
  		}
  	}
  
  	if (res_valid)
  		return 0;
  
  	dev_err(dev, "non-prefetchable memory resource required\n");
  	return -EINVAL;
  }
  
  static void gen_pci_unmap_cfg(void *ptr)
  {
  	pci_ecam_free((struct pci_config_window *)ptr);
  }
  
  static struct pci_config_window *gen_pci_init(struct device *dev,
  		struct list_head *resources, struct pci_ecam_ops *ops)
  {
  	int err;
  	struct resource cfgres;
  	struct resource *bus_range = NULL;
  	struct pci_config_window *cfg;
  
  	/* Parse our PCI ranges and request their resources */
  	err = gen_pci_parse_request_of_pci_ranges(dev, resources, &bus_range);
  	if (err)
  		goto err_out;
  
  	err = of_address_to_resource(dev->of_node, 0, &cfgres);
  	if (err) {
  		dev_err(dev, "missing \"reg\" property\n");
  		goto err_out;
  	}
  
  	cfg = pci_ecam_create(dev, &cfgres, bus_range, ops);
  	if (IS_ERR(cfg)) {
  		err = PTR_ERR(cfg);
  		goto err_out;
  	}
  
  	err = devm_add_action(dev, gen_pci_unmap_cfg, cfg);
  	if (err) {
  		gen_pci_unmap_cfg(cfg);
  		goto err_out;
  	}
  	return cfg;
  
  err_out:
  	pci_free_resource_list(resources);
  	return ERR_PTR(err);
  }
  
  int pci_host_common_probe(struct platform_device *pdev,
  			  struct pci_ecam_ops *ops)
  {
  	const char *type;
  	struct device *dev = &pdev->dev;
  	struct device_node *np = dev->of_node;
  	struct pci_bus *bus, *child;
  	struct pci_host_bridge *bridge;
  	struct pci_config_window *cfg;
  	struct list_head resources;
  	int ret;
  
  	bridge = devm_pci_alloc_host_bridge(dev, 0);
  	if (!bridge)
  		return -ENOMEM;
  
  	type = of_get_property(np, "device_type", NULL);
  	if (!type || strcmp(type, "pci")) {
  		dev_err(dev, "invalid \"device_type\" %s\n", type);
  		return -EINVAL;
  	}
  
  	of_pci_check_probe_only();
  
  	/* Parse and map our Configuration Space windows */
  	INIT_LIST_HEAD(&resources);
  	cfg = gen_pci_init(dev, &resources, ops);
  	if (IS_ERR(cfg))
  		return PTR_ERR(cfg);
  
  	/* Do not reassign resources if probe only */
  	if (!pci_has_flag(PCI_PROBE_ONLY))
  		pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
  
  	list_splice_init(&resources, &bridge->windows);
  	bridge->dev.parent = dev;
  	bridge->sysdata = cfg;
  	bridge->busnr = cfg->busr.start;
  	bridge->ops = &ops->pci_ops;
  	bridge->map_irq = of_irq_parse_and_map_pci;
  	bridge->swizzle_irq = pci_common_swizzle;
  
  	ret = pci_scan_root_bus_bridge(bridge);
  	if (ret < 0) {
  		dev_err(dev, "Scanning root bridge failed");
  		return ret;
  	}
  
  	bus = bridge->bus;
  
  	/*
  	 * We insert PCI resources into the iomem_resource and
  	 * ioport_resource trees in either pci_bus_claim_resources()
  	 * or pci_bus_assign_resources().
  	 */
  	if (pci_has_flag(PCI_PROBE_ONLY)) {
  		pci_bus_claim_resources(bus);
  	} else {
  		pci_bus_size_bridges(bus);
  		pci_bus_assign_resources(bus);
  
  		list_for_each_entry(child, &bus->children, node)
  			pcie_bus_configure_settings(child);
  	}
  
  	pci_bus_add_devices(bus);
  	return 0;
  }
  