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, &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 
53 err_out:
54 	pci_free_resource_list(resources);
55 	return ERR_PTR(err);
56 }
57 
58 int pci_host_common_probe(struct platform_device *pdev,
59 			  struct pci_ecam_ops *ops)
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 	int ret;
66 
67 	bridge = devm_pci_alloc_host_bridge(dev, 0);
68 	if (!bridge)
69 		return -ENOMEM;
70 
71 	of_pci_check_probe_only();
72 
73 	/* Parse and map our Configuration Space windows */
74 	cfg = gen_pci_init(dev, &resources, ops);
75 	if (IS_ERR(cfg))
76 		return PTR_ERR(cfg);
77 
78 	/* Do not reassign resources if probe only */
79 	if (!pci_has_flag(PCI_PROBE_ONLY))
80 		pci_add_flags(PCI_REASSIGN_ALL_BUS);
81 
82 	list_splice_init(&resources, &bridge->windows);
83 	bridge->dev.parent = dev;
84 	bridge->sysdata = cfg;
85 	bridge->busnr = cfg->busr.start;
86 	bridge->ops = &ops->pci_ops;
87 	bridge->map_irq = of_irq_parse_and_map_pci;
88 	bridge->swizzle_irq = pci_common_swizzle;
89 
90 	ret = pci_host_probe(bridge);
91 	if (ret < 0) {
92 		pci_free_resource_list(&resources);
93 		return ret;
94 	}
95 
96 	platform_set_drvdata(pdev, bridge->bus);
97 	return 0;
98 }
99 
100 int pci_host_common_remove(struct platform_device *pdev)
101 {
102 	struct pci_bus *bus = platform_get_drvdata(pdev);
103 
104 	pci_lock_rescan_remove();
105 	pci_stop_root_bus(bus);
106 	pci_remove_root_bus(bus);
107 	pci_unlock_rescan_remove();
108 
109 	return 0;
110 }
111