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/module.h>
  24 #include <linux/of_address.h>
  25 #include <linux/of_pci.h>
  26 #include <linux/platform_device.h>
  27
  28 #include "pci-host-common.h"
  29
  30 static void __iomem *gen_pci_map_cfg_bus_cam(struct pci_bus *bus,
  31                                              unsigned int devfn,
  32                                              int where)
  33 {
  34         struct gen_pci *pci = bus->sysdata;
  35         resource_size_t idx = bus->number - pci->cfg.bus_range->start;
  36
  37         return pci->cfg.win[idx] + ((devfn << 8) | where);
  38 }
  39
  40 static struct gen_pci_cfg_bus_ops gen_pci_cfg_cam_bus_ops = {
  41         .bus_shift      = 16,
  42         .ops            = {
  43                 .map_bus        = gen_pci_map_cfg_bus_cam,
  44                 .read           = pci_generic_config_read,
  45                 .write          = pci_generic_config_write,
  46         }
  47 };
  48
  49 static void __iomem *gen_pci_map_cfg_bus_ecam(struct pci_bus *bus,
  50                                               unsigned int devfn,
  51                                               int where)
  52 {
  53         struct gen_pci *pci = bus->sysdata;
  54         resource_size_t idx = bus->number - pci->cfg.bus_range->start;
  55
  56         return pci->cfg.win[idx] + ((devfn << 12) | where);
  57 }
  58
  59 static struct gen_pci_cfg_bus_ops gen_pci_cfg_ecam_bus_ops = {
  60         .bus_shift      = 20,
  61         .ops            = {
  62                 .map_bus        = gen_pci_map_cfg_bus_ecam,
  63                 .read           = pci_generic_config_read,
  64                 .write          = pci_generic_config_write,
  65         }
  66 };
  67
  68 static const struct of_device_id gen_pci_of_match[] = {
  69         { .compatible = "pci-host-cam-generic",
  70           .data = &gen_pci_cfg_cam_bus_ops },
  71
  72         { .compatible = "pci-host-ecam-generic",
  73           .data = &gen_pci_cfg_ecam_bus_ops },
  74
  75         { },
  76 };
  77 MODULE_DEVICE_TABLE(of, gen_pci_of_match);
  78
  79 static int gen_pci_probe(struct platform_device *pdev)
  80 {
  81         struct device *dev = &pdev->dev;
  82         const struct of_device_id *of_id;
  83         struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
  84
  85         if (!pci)
  86                 return -ENOMEM;
  87
  88         of_id = of_match_node(gen_pci_of_match, dev->of_node);
  89         pci->cfg.ops = (struct gen_pci_cfg_bus_ops *)of_id->data;
  90
  91         return pci_host_common_probe(pdev, pci);
  92 }
  93
  94 static struct platform_driver gen_pci_driver = {
  95         .driver = {
  96                 .name = "pci-host-generic",
  97                 .of_match_table = gen_pci_of_match,
  98         },
  99         .probe = gen_pci_probe,
 100 };
 101 module_platform_driver(gen_pci_driver);
 102
 103 MODULE_DESCRIPTION("Generic PCI host driver");
 104 MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
 105 MODULE_LICENSE("GPL v2");