xilinx_pci.c

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/*
 * PCI support for Xilinx plbv46_pci soft-core which can be used on
 * Xilinx Virtex ML410 / ML510 boards.
 *
 * Copyright 2009 Roderick Colenbrander
 * Copyright 2009 Secret Lab Technologies Ltd.
 *
 * The pci bridge fixup code was copied from ppc4xx_pci.c and was written
 * by Benjamin Herrenschmidt.
 * Copyright 2007 Ben. Herrenschmidt <[email protected]>, IBM Corp.
 *
 * This file is licensed under the terms of the GNU General Public License
 * version 2. This program is licensed "as is" without any warranty of any
 * kind, whether express or implied.
 */

#include <linux/ioport.h>
#include <linux/of.h>
#include <linux/pci.h>
#include <mm/mmu_decl.h>
#include <asm/io.h>
#include <asm/xilinx_pci.h>

#define XPLB_PCI_ADDR 0x10c
#define XPLB_PCI_DATA 0x110
#define XPLB_PCI_BUS  0x114

#define PCI_HOST_ENABLE_CMD PCI_COMMAND_SERR | PCI_COMMAND_PARITY | PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY

static struct of_device_id xilinx_pci_match[] = {
    { .compatible = "xlnx,plbv46-pci-1.03.a", },
    {}
};

static void xilinx_pci_fixup_bridge(struct pci_dev *dev)
{
    struct pci_controller *hose;
    int i;

    if (dev->devfn || dev->bus->self)
        return;

    hose = pci_bus_to_host(dev->bus);
    if (!hose)
        return;

    if (!of_match_node(xilinx_pci_match, hose->dn))
        return;

    /* Hide the PCI host BARs from the kernel as their content doesn't
     * fit well in the resource management
     */
    for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
        dev->resource[i].start = 0;
        dev->resource[i].end = 0;
        dev->resource[i].flags = 0;
    }

    dev_info(&dev->dev, "Hiding Xilinx plb-pci host bridge resources %s\n",
         pci_name(dev));
}
DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, xilinx_pci_fixup_bridge);

static int
xilinx_pci_exclude_device(struct pci_controller *hose, u_char bus, u8 devfn)
{
    return (bus != 0);
}

void __init xilinx_pci_init(void)
{
    struct pci_controller *hose;
    struct resource r;
    void __iomem *pci_reg;
    struct device_node *pci_node;

    pci_node = of_find_matching_node(NULL, xilinx_pci_match);
    if(!pci_node)
        return;

    if (of_address_to_resource(pci_node, 0, &r)) {
        pr_err("xilinx-pci: cannot resolve base address\n");
        return;
    }

    hose = pcibios_alloc_controller(pci_node);
    if (!hose) {
        pr_err("xilinx-pci: pcibios_alloc_controller() failed\n");
        return;
    }

    /* Setup config space */
    setup_indirect_pci(hose, r.start + XPLB_PCI_ADDR,
               r.start + XPLB_PCI_DATA,
               PPC_INDIRECT_TYPE_SET_CFG_TYPE);

    /* According to the xilinx plbv46_pci documentation the soft-core starts
     * a self-init when the bus master enable bit is set. Without this bit
     * set the pci bus can't be scanned.
     */
    early_write_config_word(hose, 0, 0, PCI_COMMAND, PCI_HOST_ENABLE_CMD);

    /* Set the max latency timer to 255 */
    early_write_config_byte(hose, 0, 0, PCI_LATENCY_TIMER, 0xff);

    /* Set the max bus number to 255 */
    pci_reg = of_iomap(pci_node, 0);
    out_8(pci_reg + XPLB_PCI_BUS, 0xff);
    iounmap(pci_reg);

    /* Nothing past the root bridge is working right now.  By default
     * exclude config access to anything except bus 0 */
    if (!ppc_md.pci_exclude_device)
        ppc_md.pci_exclude_device = xilinx_pci_exclude_device;

    /* Register the host bridge with the linux kernel! */
    pci_process_bridge_OF_ranges(hose, pci_node, 1);

    pr_info("xilinx-pci: Registered PCI host bridge\n");
}