1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Simple, generic PCI host controller driver targeting firmware-initialised
4  * systems and virtual machines (e.g. the PCI emulation provided by kvmtool).
5  *
6  * Copyright (C) 2014 ARM Limited
7  *
8  * Author: Will Deacon <will.deacon@arm.com>
9  */
10 
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/pci-ecam.h>
15 #include <linux/platform_device.h>
16 
17 #include "pci-host-common.h"
18 
19 static const struct pci_ecam_ops gen_pci_cfg_cam_bus_ops = {
20 	.bus_shift	= 16,
21 	.pci_ops	= {
22 		.map_bus	= pci_ecam_map_bus,
23 		.read		= pci_generic_config_read,
24 		.write		= pci_generic_config_write,
25 	}
26 };
27 
28 static bool pci_dw_valid_device(struct pci_bus *bus, unsigned int devfn)
29 {
30 	struct pci_config_window *cfg = bus->sysdata;
31 
32 	/*
33 	 * The Synopsys DesignWare PCIe controller in ECAM mode will not filter
34 	 * type 0 config TLPs sent to devices 1 and up on its downstream port,
35 	 * resulting in devices appearing multiple times on bus 0 unless we
36 	 * filter out those accesses here.
37 	 */
38 	if (bus->number == cfg->busr.start && PCI_SLOT(devfn) > 0)
39 		return false;
40 
41 	return true;
42 }
43 
44 static void __iomem *pci_dw_ecam_map_bus(struct pci_bus *bus,
45 					 unsigned int devfn, int where)
46 {
47 	if (!pci_dw_valid_device(bus, devfn))
48 		return NULL;
49 
50 	return pci_ecam_map_bus(bus, devfn, where);
51 }
52 
53 static const struct pci_ecam_ops pci_dw_ecam_bus_ops = {
54 	.pci_ops	= {
55 		.map_bus	= pci_dw_ecam_map_bus,
56 		.read		= pci_generic_config_read,
57 		.write		= pci_generic_config_write,
58 	}
59 };
60 
61 static const struct of_device_id gen_pci_of_match[] = {
62 	{ .compatible = "pci-host-cam-generic",
63 	  .data = &gen_pci_cfg_cam_bus_ops },
64 
65 	{ .compatible = "pci-host-ecam-generic",
66 	  .data = &pci_generic_ecam_ops },
67 
68 	{ .compatible = "marvell,armada8k-pcie-ecam",
69 	  .data = &pci_dw_ecam_bus_ops },
70 
71 	{ .compatible = "socionext,synquacer-pcie-ecam",
72 	  .data = &pci_dw_ecam_bus_ops },
73 
74 	{ .compatible = "snps,dw-pcie-ecam",
75 	  .data = &pci_dw_ecam_bus_ops },
76 
77 	{ },
78 };
79 MODULE_DEVICE_TABLE(of, gen_pci_of_match);
80 
81 static struct platform_driver gen_pci_driver = {
82 	.driver = {
83 		.name = "pci-host-generic",
84 		.of_match_table = gen_pci_of_match,
85 	},
86 	.probe = pci_host_common_probe,
87 	.remove = pci_host_common_remove,
88 };
89 module_platform_driver(gen_pci_driver);
90 
91 MODULE_DESCRIPTION("Generic PCI host controller driver");
92 MODULE_LICENSE("GPL v2");
93