pci-host-generic.c

 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
19static 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
28static 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
44static 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
53static 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
61static 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};
79MODULE_DEVICE_TABLE(of, gen_pci_of_match);
80
81static 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};
89module_platform_driver(gen_pci_driver);
90
91MODULE_DESCRIPTION("Generic PCI host controller driver");
92MODULE_LICENSE("GPL v2");