drivers/pci/controller/pci-versatile.c

   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
  20 static void __iomem *versatile_pci_base;
  21 static 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
  30 static u32 pci_slot_ignore;
  31
  32 static int __init versatile_pci_slot_ignore(char *str)
  33 {
  34         int slot;
  35
  36         while (get_option(&str, &slot)) {
  37                 if ((slot < 0) || (slot > 31))
  38                         pr_err("Illegal slot value: %d\n", slot);
  39                 else
  40                         pci_slot_ignore |= (1 << slot);
  41         }
  42         return 1;
  43 }
  44 __setup("pci_slot_ignore=", versatile_pci_slot_ignore);
  45
  46
  47 static void __iomem *versatile_map_bus(struct pci_bus *bus,
  48                                        unsigned int devfn, int offset)
  49 {
  50         unsigned int busnr = bus->number;
  51
  52         if (pci_slot_ignore & (1 << PCI_SLOT(devfn)))
  53                 return NULL;
  54
  55         return versatile_cfg_base[1] + ((busnr << 16) | (devfn << 8) | offset);
  56 }
  57
  58 static struct pci_ops pci_versatile_ops = {
  59         .map_bus = versatile_map_bus,
  60         .read   = pci_generic_config_read32,
  61         .write  = pci_generic_config_write,
  62 };
  63
  64 static int versatile_pci_probe(struct platform_device *pdev)
  65 {
  66         struct device *dev = &pdev->dev;
  67         struct resource *res;
  68         struct resource_entry *entry;
  69         int i, myslot = -1, mem = 1;
  70         u32 val;
  71         void __iomem *local_pci_cfg_base;
  72         struct pci_host_bridge *bridge;
  73
  74         bridge = devm_pci_alloc_host_bridge(dev, 0);
  75         if (!bridge)
  76                 return -ENOMEM;
  77
  78         versatile_pci_base = devm_platform_ioremap_resource(pdev, 0);
  79         if (IS_ERR(versatile_pci_base))
  80                 return PTR_ERR(versatile_pci_base);
  81
  82         versatile_cfg_base[0] = devm_platform_ioremap_resource(pdev, 1);
  83         if (IS_ERR(versatile_cfg_base[0]))
  84                 return PTR_ERR(versatile_cfg_base[0]);
  85
  86         res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
  87         versatile_cfg_base[1] = devm_pci_remap_cfg_resource(dev, res);
  88         if (IS_ERR(versatile_cfg_base[1]))
  89                 return PTR_ERR(versatile_cfg_base[1]);
  90
  91         resource_list_for_each_entry(entry, &bridge->windows) {
  92                 if (resource_type(entry->res) == IORESOURCE_MEM) {
  93                         writel(entry->res->start >> 28, PCI_IMAP(mem));
  94                         writel(__pa(PAGE_OFFSET) >> 28, PCI_SMAP(mem));
  95                         mem++;
  96                 }
  97         }
  98
  99         /*
 100          * We need to discover the PCI core first to configure itself
 101          * before the main PCI probing is performed
 102          */
 103         for (i = 0; i < 32; i++) {
 104                 if ((readl(versatile_cfg_base[0] + (i << 11) + PCI_VENDOR_ID) == VP_PCI_DEVICE_ID) &&
 105                     (readl(versatile_cfg_base[0] + (i << 11) + PCI_CLASS_REVISION) == VP_PCI_CLASS_ID)) {
 106                         myslot = i;
 107                         break;
 108                 }
 109         }
 110         if (myslot == -1) {
 111                 dev_err(dev, "Cannot find PCI core!\n");
 112                 return -EIO;
 113         }
 114         /*
 115          * Do not to map Versatile FPGA PCI device into memory space
 116          */
 117         pci_slot_ignore |= (1 << myslot);
 118
 119         dev_info(dev, "PCI core found (slot %d)\n", myslot);
 120
 121         writel(myslot, PCI_SELFID);
 122         local_pci_cfg_base = versatile_cfg_base[1] + (myslot << 11);
 123
 124         val = readl(local_pci_cfg_base + PCI_COMMAND);
 125         val |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_INVALIDATE;
 126         writel(val, local_pci_cfg_base + PCI_COMMAND);
 127
 128         /*
 129          * Configure the PCI inbound memory windows to be 1:1 mapped to SDRAM
 130          */
 131         writel(__pa(PAGE_OFFSET), local_pci_cfg_base + PCI_BASE_ADDRESS_0);
 132         writel(__pa(PAGE_OFFSET), local_pci_cfg_base + PCI_BASE_ADDRESS_1);
 133         writel(__pa(PAGE_OFFSET), local_pci_cfg_base + PCI_BASE_ADDRESS_2);
 134
 135         /*
 136          * For many years the kernel and QEMU were symbiotically buggy
 137          * in that they both assumed the same broken IRQ mapping.
 138          * QEMU therefore attempts to auto-detect old broken kernels
 139          * so that they still work on newer QEMU as they did on old
 140          * QEMU. Since we now use the correct (ie matching-hardware)
 141          * IRQ mapping we write a definitely different value to a
 142          * PCI_INTERRUPT_LINE register to tell QEMU that we expect
 143          * real hardware behaviour and it need not be backwards
 144          * compatible for us. This write is harmless on real hardware.
 145          */
 146         writel(0, versatile_cfg_base[0] + PCI_INTERRUPT_LINE);
 147
 148         pci_add_flags(PCI_REASSIGN_ALL_BUS);
 149
 150         bridge->ops = &pci_versatile_ops;
 151
 152         return pci_host_probe(bridge);
 153 }
 154
 155 static const struct of_device_id versatile_pci_of_match[] = {
 156         { .compatible = "arm,versatile-pci", },
 157         { },
 158 };
 159 MODULE_DEVICE_TABLE(of, versatile_pci_of_match);
 160
 161 static struct platform_driver versatile_pci_driver = {
 162         .driver = {
 163                 .name = "versatile-pci",
 164                 .of_match_table = versatile_pci_of_match,
 165                 .suppress_bind_attrs = true,
 166         },
 167         .probe = versatile_pci_probe,
 168 };
 169 module_platform_driver(versatile_pci_driver);
 170
 171 MODULE_DESCRIPTION("Versatile PCI driver");