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/module.h>
12 #include <linux/of_address.h>
13 #include <linux/of_device.h>
14 #include <linux/of_pci.h>
15 #include <linux/pci-ecam.h>
16 #include <linux/platform_device.h>
17 
18 static void gen_pci_unmap_cfg(void *ptr)
19 {
20 	pci_ecam_free((struct pci_config_window *)ptr);
21 }
22 
23 static struct pci_config_window *gen_pci_init(struct device *dev,
24 		struct pci_host_bridge *bridge, const struct pci_ecam_ops *ops)
25 {
26 	int err;
27 	struct resource cfgres;
28 	struct resource_entry *bus;
29 	struct pci_config_window *cfg;
30 
31 	err = of_address_to_resource(dev->of_node, 0, &cfgres);
32 	if (err) {
33 		dev_err(dev, "missing \"reg\" property\n");
34 		return ERR_PTR(err);
35 	}
36 
37 	bus = resource_list_first_type(&bridge->windows, IORESOURCE_BUS);
38 	if (!bus)
39 		return ERR_PTR(-ENODEV);
40 
41 	cfg = pci_ecam_create(dev, &cfgres, bus->res, ops);
42 	if (IS_ERR(cfg))
43 		return cfg;
44 
45 	err = devm_add_action_or_reset(dev, gen_pci_unmap_cfg, cfg);
46 	if (err)
47 		return ERR_PTR(err);
48 
49 	return cfg;
50 }
51 
52 int pci_host_common_probe(struct platform_device *pdev)
53 {
54 	struct device *dev = &pdev->dev;
55 	struct pci_host_bridge *bridge;
56 	struct pci_config_window *cfg;
57 	const struct pci_ecam_ops *ops;
58 
59 	ops = of_device_get_match_data(&pdev->dev);
60 	if (!ops)
61 		return -ENODEV;
62 
63 	bridge = devm_pci_alloc_host_bridge(dev, 0);
64 	if (!bridge)
65 		return -ENOMEM;
66 
67 	platform_set_drvdata(pdev, bridge);
68 
69 	of_pci_check_probe_only();
70 
71 	/* Parse and map our Configuration Space windows */
72 	cfg = gen_pci_init(dev, bridge, ops);
73 	if (IS_ERR(cfg))
74 		return PTR_ERR(cfg);
75 
76 	/* Do not reassign resources if probe only */
77 	if (!pci_has_flag(PCI_PROBE_ONLY))
78 		pci_add_flags(PCI_REASSIGN_ALL_BUS);
79 
80 	bridge->sysdata = cfg;
81 	bridge->ops = (struct pci_ops *)&ops->pci_ops;
82 
83 	return pci_host_probe(bridge);
84 }
85 EXPORT_SYMBOL_GPL(pci_host_common_probe);
86 
87 int pci_host_common_remove(struct platform_device *pdev)
88 {
89 	struct pci_host_bridge *bridge = platform_get_drvdata(pdev);
90 
91 	pci_lock_rescan_remove();
92 	pci_stop_root_bus(bridge->bus);
93 	pci_remove_root_bus(bridge->bus);
94 	pci_unlock_rescan_remove();
95 
96 	return 0;
97 }
98 EXPORT_SYMBOL_GPL(pci_host_common_remove);
99 
100 MODULE_LICENSE("GPL v2");
101