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, NULL, &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 
52 err_out:
53 	pci_free_resource_list(resources);
54 	return ERR_PTR(err);
55 }
56 
57 int 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 
99 int 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 }
110