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 static 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
pci_dw_valid_device(struct pci_bus * bus,unsigned int devfn)26 static 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
pci_dw_ecam_map_bus(struct pci_bus * bus,unsigned int devfn,int where)42 static 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
51 static 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
59 static 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 };
77 MODULE_DEVICE_TABLE(of, gen_pci_of_match);
78
79 static 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 = pci_host_common_remove,
86 };
87 module_platform_driver(gen_pci_driver);
88
89 MODULE_LICENSE("GPL v2");
90
