drivers/pci/host/pci-host-generic.c

   1 /*
   2  * Simple, generic PCI host controller driver targetting firmware-initialised
   3  * systems and virtual machines (e.g. the PCI emulation provided by kvmtool).
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  *
  17  * Copyright (C) 2014 ARM Limited
  18  *
  19  * Author: Will Deacon <will.deacon@arm.com>
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/init.h>
  24 #include <linux/of_address.h>
  25 #include <linux/of_pci.h>
  26 #include <linux/pci-ecam.h>
  27 #include <linux/platform_device.h>
  28
  29 static struct pci_ecam_ops gen_pci_cfg_cam_bus_ops = {
  30         .bus_shift      = 16,
  31         .pci_ops        = {
  32                 .map_bus        = pci_ecam_map_bus,
  33                 .read           = pci_generic_config_read,
  34                 .write          = pci_generic_config_write,
  35         }
  36 };
  37
  38 static bool pci_dw_valid_device(struct pci_bus *bus, unsigned int devfn)
  39 {
  40         struct pci_config_window *cfg = bus->sysdata;
  41
  42         /*
  43          * The Synopsys DesignWare PCIe controller in ECAM mode will not filter
  44          * type 0 config TLPs sent to devices 1 and up on its downstream port,
  45          * resulting in devices appearing multiple times on bus 0 unless we
  46          * filter out those accesses here.
  47          */
  48         if (bus->number == cfg->busr.start && PCI_SLOT(devfn) > 0)
  49                 return false;
  50
  51         return true;
  52 }
  53
  54 static void __iomem *pci_dw_ecam_map_bus(struct pci_bus *bus,
  55                                          unsigned int devfn, int where)
  56 {
  57         if (!pci_dw_valid_device(bus, devfn))
  58                 return NULL;
  59
  60         return pci_ecam_map_bus(bus, devfn, where);
  61 }
  62
  63 static struct pci_ecam_ops pci_dw_ecam_bus_ops = {
  64         .bus_shift      = 20,
  65         .pci_ops        = {
  66                 .map_bus        = pci_dw_ecam_map_bus,
  67                 .read           = pci_generic_config_read,
  68                 .write          = pci_generic_config_write,
  69         }
  70 };
  71
  72 static const struct of_device_id gen_pci_of_match[] = {
  73         { .compatible = "pci-host-cam-generic",
  74           .data = &gen_pci_cfg_cam_bus_ops },
  75
  76         { .compatible = "pci-host-ecam-generic",
  77           .data = &pci_generic_ecam_ops },
  78
  79         { .compatible = "marvell,armada8k-pcie-ecam",
  80           .data = &pci_dw_ecam_bus_ops },
  81
  82         { .compatible = "socionext,synquacer-pcie-ecam",
  83           .data = &pci_dw_ecam_bus_ops },
  84
  85         { .compatible = "snps,dw-pcie-ecam",
  86           .data = &pci_dw_ecam_bus_ops },
  87
  88         { },
  89 };
  90
  91 static int gen_pci_probe(struct platform_device *pdev)
  92 {
  93         const struct of_device_id *of_id;
  94         struct pci_ecam_ops *ops;
  95
  96         of_id = of_match_node(gen_pci_of_match, pdev->dev.of_node);
  97         ops = (struct pci_ecam_ops *)of_id->data;
  98
  99         return pci_host_common_probe(pdev, ops);
 100 }
 101
 102 static struct platform_driver gen_pci_driver = {
 103         .driver = {
 104                 .name = "pci-host-generic",
 105                 .of_match_table = gen_pci_of_match,
 106                 .suppress_bind_attrs = true,
 107         },
 108         .probe = gen_pci_probe,
 109 };
 110 builtin_platform_driver(gen_pci_driver);