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(dev, gen_pci_unmap_cfg, cfg);
 47	if (err) {
 48		gen_pci_unmap_cfg(cfg);
 49		goto err_out;
 50	}
 51	return cfg;
 52
 53err_out:
 54	pci_free_resource_list(resources);
 55	return ERR_PTR(err);
 56}
 57
 58int 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}