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
 16static void gen_pci_unmap_cfg(void *ptr)
 17{
 18	pci_ecam_free((struct pci_config_window *)ptr);
 19}
 20
 21static 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_or_reset(dev, gen_pci_unmap_cfg, cfg);
 47	if (err) {
 48		goto err_out;
 49	}
 50	return cfg;
 51
 52err_out:
 53	pci_free_resource_list(resources);
 54	return ERR_PTR(err);
 55}
 56
 57int 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
 99int 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}