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
pci_dw_valid_device(struct pci_bus * bus,unsigned int devfn)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
pci_dw_ecam_map_bus(struct pci_bus * bus,unsigned int devfn,int where)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