linux/drivers/pci/controller/pci-versatile.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright 2004 Koninklijke Philips Electronics NV
   4 *
   5 * Conversion to platform driver and DT:
   6 * Copyright 2014 Linaro Ltd.
   7 *
   8 * 14/04/2005 Initial version, colin.king@philips.com
   9 */
  10#include <linux/kernel.h>
  11#include <linux/module.h>
  12#include <linux/of_address.h>
  13#include <linux/of_pci.h>
  14#include <linux/of_platform.h>
  15#include <linux/pci.h>
  16#include <linux/platform_device.h>
  17
  18#include "../pci.h"
  19
  20static void __iomem *versatile_pci_base;
  21static void __iomem *versatile_cfg_base[2];
  22
  23#define PCI_IMAP(m)             (versatile_pci_base + ((m) * 4))
  24#define PCI_SMAP(m)             (versatile_pci_base + 0x14 + ((m) * 4))
  25#define PCI_SELFID              (versatile_pci_base + 0xc)
  26
  27#define VP_PCI_DEVICE_ID                0x030010ee
  28#define VP_PCI_CLASS_ID                 0x0b400000
  29
  30static u32 pci_slot_ignore;
  31
  32static int __init versatile_pci_slot_ignore(char *str)
  33{
  34        int retval;
  35        int slot;
  36
  37        while ((retval = get_option(&str, &slot))) {
  38                if ((slot < 0) || (slot > 31))
  39                        pr_err("Illegal slot value: %d\n", slot);
  40                else
  41                        pci_slot_ignore |= (1 << slot);
  42        }
  43        return 1;
  44}
  45__setup("pci_slot_ignore=", versatile_pci_slot_ignore);
  46
  47
  48static void __iomem *versatile_map_bus(struct pci_bus *bus,
  49                                       unsigned int devfn, int offset)
  50{
  51        unsigned int busnr = bus->number;
  52
  53        if (pci_slot_ignore & (1 << PCI_SLOT(devfn)))
  54                return NULL;
  55
  56        return versatile_cfg_base[1] + ((busnr << 16) | (devfn << 8) | offset);
  57}
  58
  59static struct pci_ops pci_versatile_ops = {
  60        .map_bus = versatile_map_bus,
  61        .read   = pci_generic_config_read32,
  62        .write  = pci_generic_config_write,
  63};
  64
  65static int versatile_pci_parse_request_of_pci_ranges(struct device *dev,
  66                                                     struct list_head *res)
  67{
  68        int err, mem = 1, res_valid = 0;
  69        resource_size_t iobase;
  70        struct resource_entry *win, *tmp;
  71
  72        err = devm_of_pci_get_host_bridge_resources(dev, 0, 0xff, res, &iobase);
  73        if (err)
  74                return err;
  75
  76        err = devm_request_pci_bus_resources(dev, res);
  77        if (err)
  78                goto out_release_res;
  79
  80        resource_list_for_each_entry_safe(win, tmp, res) {
  81                struct resource *res = win->res;
  82
  83                switch (resource_type(res)) {
  84                case IORESOURCE_IO:
  85                        err = devm_pci_remap_iospace(dev, res, iobase);
  86                        if (err) {
  87                                dev_warn(dev, "error %d: failed to map resource %pR\n",
  88                                         err, res);
  89                                resource_list_destroy_entry(win);
  90                        }
  91                        break;
  92                case IORESOURCE_MEM:
  93                        res_valid |= !(res->flags & IORESOURCE_PREFETCH);
  94
  95                        writel(res->start >> 28, PCI_IMAP(mem));
  96                        writel(PHYS_OFFSET >> 28, PCI_SMAP(mem));
  97                        mem++;
  98
  99                        break;
 100                }
 101        }
 102
 103        if (res_valid)
 104                return 0;
 105
 106        dev_err(dev, "non-prefetchable memory resource required\n");
 107        err = -EINVAL;
 108
 109out_release_res:
 110        pci_free_resource_list(res);
 111        return err;
 112}
 113
 114static int versatile_pci_probe(struct platform_device *pdev)
 115{
 116        struct device *dev = &pdev->dev;
 117        struct resource *res;
 118        int ret, i, myslot = -1;
 119        u32 val;
 120        void __iomem *local_pci_cfg_base;
 121        struct pci_bus *bus, *child;
 122        struct pci_host_bridge *bridge;
 123        LIST_HEAD(pci_res);
 124
 125        bridge = devm_pci_alloc_host_bridge(dev, 0);
 126        if (!bridge)
 127                return -ENOMEM;
 128
 129        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 130        versatile_pci_base = devm_ioremap_resource(dev, res);
 131        if (IS_ERR(versatile_pci_base))
 132                return PTR_ERR(versatile_pci_base);
 133
 134        res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 135        versatile_cfg_base[0] = devm_ioremap_resource(dev, res);
 136        if (IS_ERR(versatile_cfg_base[0]))
 137                return PTR_ERR(versatile_cfg_base[0]);
 138
 139        res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
 140        versatile_cfg_base[1] = devm_pci_remap_cfg_resource(dev, res);
 141        if (IS_ERR(versatile_cfg_base[1]))
 142                return PTR_ERR(versatile_cfg_base[1]);
 143
 144        ret = versatile_pci_parse_request_of_pci_ranges(dev, &pci_res);
 145        if (ret)
 146                return ret;
 147
 148        /*
 149         * We need to discover the PCI core first to configure itself
 150         * before the main PCI probing is performed
 151         */
 152        for (i = 0; i < 32; i++) {
 153                if ((readl(versatile_cfg_base[0] + (i << 11) + PCI_VENDOR_ID) == VP_PCI_DEVICE_ID) &&
 154                    (readl(versatile_cfg_base[0] + (i << 11) + PCI_CLASS_REVISION) == VP_PCI_CLASS_ID)) {
 155                        myslot = i;
 156                        break;
 157                }
 158        }
 159        if (myslot == -1) {
 160                dev_err(dev, "Cannot find PCI core!\n");
 161                return -EIO;
 162        }
 163        /*
 164         * Do not to map Versatile FPGA PCI device into memory space
 165         */
 166        pci_slot_ignore |= (1 << myslot);
 167
 168        dev_info(dev, "PCI core found (slot %d)\n", myslot);
 169
 170        writel(myslot, PCI_SELFID);
 171        local_pci_cfg_base = versatile_cfg_base[1] + (myslot << 11);
 172
 173        val = readl(local_pci_cfg_base + PCI_COMMAND);
 174        val |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_INVALIDATE;
 175        writel(val, local_pci_cfg_base + PCI_COMMAND);
 176
 177        /*
 178         * Configure the PCI inbound memory windows to be 1:1 mapped to SDRAM
 179         */
 180        writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_0);
 181        writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_1);
 182        writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_2);
 183
 184        /*
 185         * For many years the kernel and QEMU were symbiotically buggy
 186         * in that they both assumed the same broken IRQ mapping.
 187         * QEMU therefore attempts to auto-detect old broken kernels
 188         * so that they still work on newer QEMU as they did on old
 189         * QEMU. Since we now use the correct (ie matching-hardware)
 190         * IRQ mapping we write a definitely different value to a
 191         * PCI_INTERRUPT_LINE register to tell QEMU that we expect
 192         * real hardware behaviour and it need not be backwards
 193         * compatible for us. This write is harmless on real hardware.
 194         */
 195        writel(0, versatile_cfg_base[0] + PCI_INTERRUPT_LINE);
 196
 197        pci_add_flags(PCI_ENABLE_PROC_DOMAINS);
 198        pci_add_flags(PCI_REASSIGN_ALL_BUS);
 199
 200        list_splice_init(&pci_res, &bridge->windows);
 201        bridge->dev.parent = dev;
 202        bridge->sysdata = NULL;
 203        bridge->busnr = 0;
 204        bridge->ops = &pci_versatile_ops;
 205        bridge->map_irq = of_irq_parse_and_map_pci;
 206        bridge->swizzle_irq = pci_common_swizzle;
 207
 208        ret = pci_scan_root_bus_bridge(bridge);
 209        if (ret < 0)
 210                return ret;
 211
 212        bus = bridge->bus;
 213
 214        pci_assign_unassigned_bus_resources(bus);
 215        list_for_each_entry(child, &bus->children, node)
 216                pcie_bus_configure_settings(child);
 217        pci_bus_add_devices(bus);
 218
 219        return 0;
 220}
 221
 222static const struct of_device_id versatile_pci_of_match[] = {
 223        { .compatible = "arm,versatile-pci", },
 224        { },
 225};
 226MODULE_DEVICE_TABLE(of, versatile_pci_of_match);
 227
 228static struct platform_driver versatile_pci_driver = {
 229        .driver = {
 230                .name = "versatile-pci",
 231                .of_match_table = versatile_pci_of_match,
 232                .suppress_bind_attrs = true,
 233        },
 234        .probe = versatile_pci_probe,
 235};
 236module_platform_driver(versatile_pci_driver);
 237
 238MODULE_DESCRIPTION("Versatile PCI driver");
 239MODULE_LICENSE("GPL v2");
 240