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 list_head *resources, const struct pci_ecam_ops *ops)
25 {
26 	int err;
27 	struct resource cfgres;
28 	struct resource *bus_range = NULL;
29 	struct pci_config_window *cfg;
30 
31 	/* Parse our PCI ranges and request their resources */
32 	err = pci_parse_request_of_pci_ranges(dev, resources, NULL, &bus_range);
33 	if (err)
34 		return ERR_PTR(err);
35 
36 	err = of_address_to_resource(dev->of_node, 0, &cfgres);
37 	if (err) {
38 		dev_err(dev, "missing \"reg\" property\n");
39 		goto err_out;
40 	}
41 
42 	cfg = pci_ecam_create(dev, &cfgres, bus_range, ops);
43 	if (IS_ERR(cfg)) {
44 		err = PTR_ERR(cfg);
45 		goto err_out;
46 	}
47 
48 	err = devm_add_action_or_reset(dev, gen_pci_unmap_cfg, cfg);
49 	if (err) {
50 		goto err_out;
51 	}
52 	return cfg;
53 
54 err_out:
55 	pci_free_resource_list(resources);
56 	return ERR_PTR(err);
57 }
58 
59 int pci_host_common_probe(struct platform_device *pdev)
60 {
61 	struct device *dev = &pdev->dev;
62 	struct pci_host_bridge *bridge;
63 	struct pci_config_window *cfg;
64 	struct list_head resources;
65 	const struct pci_ecam_ops *ops;
66 	int ret;
67 
68 	ops = of_device_get_match_data(&pdev->dev);
69 	if (!ops)
70 		return -ENODEV;
71 
72 	bridge = devm_pci_alloc_host_bridge(dev, 0);
73 	if (!bridge)
74 		return -ENOMEM;
75 
76 	of_pci_check_probe_only();
77 
78 	/* Parse and map our Configuration Space windows */
79 	cfg = gen_pci_init(dev, &resources, ops);
80 	if (IS_ERR(cfg))
81 		return PTR_ERR(cfg);
82 
83 	/* Do not reassign resources if probe only */
84 	if (!pci_has_flag(PCI_PROBE_ONLY))
85 		pci_add_flags(PCI_REASSIGN_ALL_BUS);
86 
87 	list_splice_init(&resources, &bridge->windows);
88 	bridge->dev.parent = dev;
89 	bridge->sysdata = cfg;
90 	bridge->busnr = cfg->busr.start;
91 	bridge->ops = (struct pci_ops *)&ops->pci_ops;
92 	bridge->map_irq = of_irq_parse_and_map_pci;
93 	bridge->swizzle_irq = pci_common_swizzle;
94 
95 	ret = pci_host_probe(bridge);
96 	if (ret < 0) {
97 		pci_free_resource_list(&resources);
98 		return ret;
99 	}
100 
101 	platform_set_drvdata(pdev, bridge->bus);
102 	return 0;
103 }
104 EXPORT_SYMBOL_GPL(pci_host_common_probe);
105 
106 int pci_host_common_remove(struct platform_device *pdev)
107 {
108 	struct pci_bus *bus = platform_get_drvdata(pdev);
109 
110 	pci_lock_rescan_remove();
111 	pci_stop_root_bus(bus);
112 	pci_remove_root_bus(bus);
113 	pci_unlock_rescan_remove();
114 
115 	return 0;
116 }
117 EXPORT_SYMBOL_GPL(pci_host_common_remove);
118 
119 MODULE_LICENSE("GPL v2");
120