// SPDX-License-Identifier: GPL-2.0
/*
 * Simple, generic PCI host controller driver targeting firmware-initialised
 * systems and virtual machines (e.g. the PCI emulation provided by kvmtool).
 *
 * Copyright (C) 2014 ARM Limited
 *
 * Author: Will Deacon <will.deacon@arm.com>
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci-ecam.h>
#include <linux/platform_device.h>

#include "pci-host-common.h"

static const struct pci_ecam_ops gen_pci_cfg_cam_bus_ops = {
        .bus_shift      = 16,
        .pci_ops        = {
                .map_bus        = pci_ecam_map_bus,
                .read           = pci_generic_config_read,
                .write          = pci_generic_config_write,
        }
};

static bool pci_dw_valid_device(struct pci_bus *bus, unsigned int devfn)
{
        struct pci_config_window *cfg = bus->sysdata;

        /*
         * The Synopsys DesignWare PCIe controller in ECAM mode will not filter
         * type 0 config TLPs sent to devices 1 and up on its downstream port,
         * resulting in devices appearing multiple times on bus 0 unless we
         * filter out those accesses here.
         */
        if (bus->number == cfg->busr.start && PCI_SLOT(devfn) > 0)
                return false;

        return true;
}

static void __iomem *pci_dw_ecam_map_bus(struct pci_bus *bus,
                                         unsigned int devfn, int where)
{
        if (!pci_dw_valid_device(bus, devfn))
                return NULL;

        return pci_ecam_map_bus(bus, devfn, where);
}

static const struct pci_ecam_ops pci_dw_ecam_bus_ops = {
        .pci_ops        = {
                .map_bus        = pci_dw_ecam_map_bus,
                .read           = pci_generic_config_read,
                .write          = pci_generic_config_write,
        }
};

static const struct of_device_id gen_pci_of_match[] = {
        { .compatible = "pci-host-cam-generic",
          .data = &gen_pci_cfg_cam_bus_ops },

        { .compatible = "pci-host-ecam-generic",
          .data = &pci_generic_ecam_ops },

        { .compatible = "marvell,armada8k-pcie-ecam",
          .data = &pci_dw_ecam_bus_ops },

        { .compatible = "socionext,synquacer-pcie-ecam",
          .data = &pci_dw_ecam_bus_ops },

        { .compatible = "snps,dw-pcie-ecam",
          .data = &pci_dw_ecam_bus_ops },

        { },
};
MODULE_DEVICE_TABLE(of, gen_pci_of_match);

static struct platform_driver gen_pci_driver = {
        .driver = {
                .name = "pci-host-generic",
                .of_match_table = gen_pci_of_match,
        },
        .probe = pci_host_common_probe,
        .remove = pci_host_common_remove,
};
module_platform_driver(gen_pci_driver);

MODULE_DESCRIPTION("Generic PCI host controller driver");
MODULE_LICENSE("GPL v2");