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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Generic PCI host driver common code
   4  *
   5  * Copyright (C) 2014 ARM Limited
   6  *
   7  * Author: Will Deacon <will.deacon@arm.com>
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/of_address.h>
  12 #include <linux/of_pci.h>
  13 #include <linux/pci-ecam.h>
  14 #include <linux/platform_device.h>
  15
  16 static void gen_pci_unmap_cfg(void *ptr)
  17 {
  18         pci_ecam_free((struct pci_config_window *)ptr);
  19 }
  20
  21 static struct pci_config_window *gen_pci_init(struct device *dev,
  22                 struct list_head *resources, struct pci_ecam_ops *ops)
  23 {
  24         int err;
  25         struct resource cfgres;
  26         struct resource *bus_range = NULL;
  27         struct pci_config_window *cfg;
  28
  29         /* Parse our PCI ranges and request their resources */
  30         err = pci_parse_request_of_pci_ranges(dev, resources, &bus_range);
  31         if (err)
  32                 return ERR_PTR(err);
  33
  34         err = of_address_to_resource(dev->of_node, 0, &cfgres);
  35         if (err) {
  36                 dev_err(dev, "missing \"reg\" property\n");
  37                 goto err_out;
  38         }
  39
  40         cfg = pci_ecam_create(dev, &cfgres, bus_range, ops);
  41         if (IS_ERR(cfg)) {
  42                 err = PTR_ERR(cfg);
  43                 goto err_out;
  44         }
  45
  46         err = devm_add_action(dev, gen_pci_unmap_cfg, cfg);
  47         if (err) {
  48                 gen_pci_unmap_cfg(cfg);
  49                 goto err_out;
  50         }
  51         return cfg;
  52
  53 err_out:
  54         pci_free_resource_list(resources);
  55         return ERR_PTR(err);
  56 }
  57
  58 int pci_host_common_probe(struct platform_device *pdev,
  59                           struct pci_ecam_ops *ops)
  60 {
  61         const char *type;
  62         struct device *dev = &pdev->dev;
  63         struct device_node *np = dev->of_node;
  64         struct pci_host_bridge *bridge;
  65         struct pci_config_window *cfg;
  66         struct list_head resources;
  67         int ret;
  68
  69         bridge = devm_pci_alloc_host_bridge(dev, 0);
  70         if (!bridge)
  71                 return -ENOMEM;
  72
  73         type = of_get_property(np, "device_type", NULL);
  74         if (!type || strcmp(type, "pci")) {
  75                 dev_err(dev, "invalid \"device_type\" %s\n", type);
  76                 return -EINVAL;
  77         }
  78
  79         of_pci_check_probe_only();
  80
  81         /* Parse and map our Configuration Space windows */
  82         cfg = gen_pci_init(dev, &resources, ops);
  83         if (IS_ERR(cfg))
  84                 return PTR_ERR(cfg);
  85
  86         /* Do not reassign resources if probe only */
  87         if (!pci_has_flag(PCI_PROBE_ONLY))
  88                 pci_add_flags(PCI_REASSIGN_ALL_BUS);
  89
  90         list_splice_init(&resources, &bridge->windows);
  91         bridge->dev.parent = dev;
  92         bridge->sysdata = cfg;
  93         bridge->busnr = cfg->busr.start;
  94         bridge->ops = &ops->pci_ops;
  95         bridge->map_irq = of_irq_parse_and_map_pci;
  96         bridge->swizzle_irq = pci_common_swizzle;
  97
  98         ret = pci_host_probe(bridge);
  99         if (ret < 0) {
 100                 pci_free_resource_list(&resources);
 101                 return ret;
 102         }
 103
 104         return 0;
 105 }