drivers/pci/controller/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, NULL, &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_or_reset(dev, gen_pci_unmap_cfg, cfg);
  47         if (err) {
  48                 goto err_out;
  49         }
  50         return cfg;
  51
  52 err_out:
  53         pci_free_resource_list(resources);
  54         return ERR_PTR(err);
  55 }
  56
  57 int pci_host_common_probe(struct platform_device *pdev,
  58                           struct pci_ecam_ops *ops)
  59 {
  60         struct device *dev = &pdev->dev;
  61         struct pci_host_bridge *bridge;
  62         struct pci_config_window *cfg;
  63         struct list_head resources;
  64         int ret;
  65
  66         bridge = devm_pci_alloc_host_bridge(dev, 0);
  67         if (!bridge)
  68                 return -ENOMEM;
  69
  70         of_pci_check_probe_only();
  71
  72         /* Parse and map our Configuration Space windows */
  73         cfg = gen_pci_init(dev, &resources, ops);
  74         if (IS_ERR(cfg))
  75                 return PTR_ERR(cfg);
  76
  77         /* Do not reassign resources if probe only */
  78         if (!pci_has_flag(PCI_PROBE_ONLY))
  79                 pci_add_flags(PCI_REASSIGN_ALL_BUS);
  80
  81         list_splice_init(&resources, &bridge->windows);
  82         bridge->dev.parent = dev;
  83         bridge->sysdata = cfg;
  84         bridge->busnr = cfg->busr.start;
  85         bridge->ops = &ops->pci_ops;
  86         bridge->map_irq = of_irq_parse_and_map_pci;
  87         bridge->swizzle_irq = pci_common_swizzle;
  88
  89         ret = pci_host_probe(bridge);
  90         if (ret < 0) {
  91                 pci_free_resource_list(&resources);
  92                 return ret;
  93         }
  94
  95         platform_set_drvdata(pdev, bridge->bus);
  96         return 0;
  97 }
  98
  99 int pci_host_common_remove(struct platform_device *pdev)
 100 {
 101         struct pci_bus *bus = platform_get_drvdata(pdev);
 102
 103         pci_lock_rescan_remove();
 104         pci_stop_root_bus(bus);
 105         pci_remove_root_bus(bus);
 106         pci_unlock_rescan_remove();
 107
 108         return 0;
 109 }