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
17static const struct pci_ecam_ops gen_pci_cfg_cam_bus_ops = {
18	.bus_shift	= 16,
19	.pci_ops	= {
20		.map_bus	= pci_ecam_map_bus,
21		.read		= pci_generic_config_read,
22		.write		= pci_generic_config_write,
23	}
24};
25
26static bool pci_dw_valid_device(struct pci_bus *bus, unsigned int devfn)
27{
28	struct pci_config_window *cfg = bus->sysdata;
29
30	/*
31	 * The Synopsys DesignWare PCIe controller in ECAM mode will not filter
32	 * type 0 config TLPs sent to devices 1 and up on its downstream port,
33	 * resulting in devices appearing multiple times on bus 0 unless we
34	 * filter out those accesses here.
35	 */
36	if (bus->number == cfg->busr.start && PCI_SLOT(devfn) > 0)
37		return false;
38
39	return true;
40}
41
42static void __iomem *pci_dw_ecam_map_bus(struct pci_bus *bus,
43					 unsigned int devfn, int where)
44{
45	if (!pci_dw_valid_device(bus, devfn))
46		return NULL;
47
48	return pci_ecam_map_bus(bus, devfn, where);
49}
50
51static const struct pci_ecam_ops pci_dw_ecam_bus_ops = {
52	.pci_ops	= {
53		.map_bus	= pci_dw_ecam_map_bus,
54		.read		= pci_generic_config_read,
55		.write		= pci_generic_config_write,
56	}
57};
58
59static const struct of_device_id gen_pci_of_match[] = {
60	{ .compatible = "pci-host-cam-generic",
61	  .data = &gen_pci_cfg_cam_bus_ops },
62
63	{ .compatible = "pci-host-ecam-generic",
64	  .data = &pci_generic_ecam_ops },
65
66	{ .compatible = "marvell,armada8k-pcie-ecam",
67	  .data = &pci_dw_ecam_bus_ops },
68
69	{ .compatible = "socionext,synquacer-pcie-ecam",
70	  .data = &pci_dw_ecam_bus_ops },
71
72	{ .compatible = "snps,dw-pcie-ecam",
73	  .data = &pci_dw_ecam_bus_ops },
74
75	{ },
76};
77MODULE_DEVICE_TABLE(of, gen_pci_of_match);
78
79static struct platform_driver gen_pci_driver = {
80	.driver = {
81		.name = "pci-host-generic",
82		.of_match_table = gen_pci_of_match,
83	},
84	.probe = pci_host_common_probe,
85	.remove_new = pci_host_common_remove,
86};
87module_platform_driver(gen_pci_driver);
88
89MODULE_LICENSE("GPL v2");
90