drivers/pci/host/pci-host-common.c

   1 /*
   2  * This program is free software; you can redistribute it and/or modify
   3  * it under the terms of the GNU General Public License version 2 as
   4  * published by the Free Software Foundation.
   5  *
   6  * This program is distributed in the hope that it will be useful,
   7  * but WITHOUT ANY WARRANTY; without even the implied warranty of
   8  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   9  * GNU General Public License for more details.
  10  *
  11  * You should have received a copy of the GNU General Public License
  12  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  13  *
  14  * Copyright (C) 2014 ARM Limited
  15  *
  16  * Author: Will Deacon <will.deacon@arm.com>
  17  */
  18
  19 #include <linux/kernel.h>
  20 #include <linux/module.h>
  21 #include <linux/of_address.h>
  22 #include <linux/of_pci.h>
  23 #include <linux/platform_device.h>
  24
  25 #include "../ecam.h"
  26
  27 static int gen_pci_parse_request_of_pci_ranges(struct device *dev,
  28                        struct list_head *resources, struct resource **bus_range)
  29 {
  30         int err, res_valid = 0;
  31         struct device_node *np = dev->of_node;
  32         resource_size_t iobase;
  33         struct resource_entry *win;
  34
  35         err = of_pci_get_host_bridge_resources(np, 0, 0xff, resources, &iobase);
  36         if (err)
  37                 return err;
  38
  39         resource_list_for_each_entry(win, resources) {
  40                 struct resource *parent, *res = win->res;
  41
  42                 switch (resource_type(res)) {
  43                 case IORESOURCE_IO:
  44                         parent = &ioport_resource;
  45                         err = pci_remap_iospace(res, iobase);
  46                         if (err) {
  47                                 dev_warn(dev, "error %d: failed to map resource %pR\n",
  48                                          err, res);
  49                                 continue;
  50                         }
  51                         break;
  52                 case IORESOURCE_MEM:
  53                         parent = &iomem_resource;
  54                         res_valid |= !(res->flags & IORESOURCE_PREFETCH);
  55                         break;
  56                 case IORESOURCE_BUS:
  57                         *bus_range = res;
  58                 default:
  59                         continue;
  60                 }
  61
  62                 err = devm_request_resource(dev, parent, res);
  63                 if (err)
  64                         goto out_release_res;
  65         }
  66
  67         if (!res_valid) {
  68                 dev_err(dev, "non-prefetchable memory resource required\n");
  69                 err = -EINVAL;
  70                 goto out_release_res;
  71         }
  72
  73         return 0;
  74
  75 out_release_res:
  76         return err;
  77 }
  78
  79 static void gen_pci_unmap_cfg(void *ptr)
  80 {
  81         pci_ecam_free((struct pci_config_window *)ptr);
  82 }
  83
  84 static struct pci_config_window *gen_pci_init(struct device *dev,
  85                 struct list_head *resources, struct pci_ecam_ops *ops)
  86 {
  87         int err;
  88         struct resource cfgres;
  89         struct resource *bus_range = NULL;
  90         struct pci_config_window *cfg;
  91
  92         /* Parse our PCI ranges and request their resources */
  93         err = gen_pci_parse_request_of_pci_ranges(dev, resources, &bus_range);
  94         if (err)
  95                 goto err_out;
  96
  97         err = of_address_to_resource(dev->of_node, 0, &cfgres);
  98         if (err) {
  99                 dev_err(dev, "missing \"reg\" property\n");
 100                 goto err_out;
 101         }
 102
 103         cfg = pci_ecam_create(dev, &cfgres, bus_range, ops);
 104         if (IS_ERR(cfg)) {
 105                 err = PTR_ERR(cfg);
 106                 goto err_out;
 107         }
 108
 109         err = devm_add_action(dev, gen_pci_unmap_cfg, cfg);
 110         if (err) {
 111                 gen_pci_unmap_cfg(cfg);
 112                 goto err_out;
 113         }
 114         return cfg;
 115
 116 err_out:
 117         pci_free_resource_list(resources);
 118         return ERR_PTR(err);
 119 }
 120
 121 int pci_host_common_probe(struct platform_device *pdev,
 122                           struct pci_ecam_ops *ops)
 123 {
 124         const char *type;
 125         struct device *dev = &pdev->dev;
 126         struct device_node *np = dev->of_node;
 127         struct pci_bus *bus, *child;
 128         struct pci_config_window *cfg;
 129         struct list_head resources;
 130
 131         type = of_get_property(np, "device_type", NULL);
 132         if (!type || strcmp(type, "pci")) {
 133                 dev_err(dev, "invalid \"device_type\" %s\n", type);
 134                 return -EINVAL;
 135         }
 136
 137         of_pci_check_probe_only();
 138
 139         /* Parse and map our Configuration Space windows */
 140         INIT_LIST_HEAD(&resources);
 141         cfg = gen_pci_init(dev, &resources, ops);
 142         if (IS_ERR(cfg))
 143                 return PTR_ERR(cfg);
 144
 145         /* Do not reassign resources if probe only */
 146         if (!pci_has_flag(PCI_PROBE_ONLY))
 147                 pci_add_flags(PCI_REASSIGN_ALL_RSRC | PCI_REASSIGN_ALL_BUS);
 148
 149         bus = pci_scan_root_bus(dev, cfg->busr.start, &ops->pci_ops, cfg,
 150                                 &resources);
 151         if (!bus) {
 152                 dev_err(dev, "Scanning rootbus failed");
 153                 return -ENODEV;
 154         }
 155
 156         pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
 157
 158         if (!pci_has_flag(PCI_PROBE_ONLY)) {
 159                 pci_bus_size_bridges(bus);
 160                 pci_bus_assign_resources(bus);
 161
 162                 list_for_each_entry(child, &bus->children, node)
 163                         pcie_bus_configure_settings(child);
 164         }
 165
 166         pci_bus_add_devices(bus);
 167         return 0;
 168 }
 169
 170 MODULE_DESCRIPTION("Generic PCI host driver common code");
 171 MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
 172 MODULE_LICENSE("GPL v2");