drivers/pci/host/pci-versatile.c

   1 /*
   2  * Copyright 2004 Koninklijke Philips Electronics NV
   3  *
   4  * Conversion to platform driver and DT:
   5  * Copyright 2014 Linaro Ltd.
   6  *
   7  * This software is licensed under the terms of the GNU General Public
   8  * License version 2, as published by the Free Software Foundation, and
   9  * may be copied, distributed, and modified under those terms.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * 14/04/2005 Initial version, colin.king@philips.com
  17  */
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/of_address.h>
  21 #include <linux/of_pci.h>
  22 #include <linux/of_platform.h>
  23 #include <linux/pci.h>
  24 #include <linux/platform_device.h>
  25
  26 static void __iomem *versatile_pci_base;
  27 static void __iomem *versatile_cfg_base[2];
  28
  29 #define PCI_IMAP(m)             (versatile_pci_base + ((m) * 4))
  30 #define PCI_SMAP(m)             (versatile_pci_base + 0x14 + ((m) * 4))
  31 #define PCI_SELFID              (versatile_pci_base + 0xc)
  32
  33 #define VP_PCI_DEVICE_ID                0x030010ee
  34 #define VP_PCI_CLASS_ID                 0x0b400000
  35
  36 static u32 pci_slot_ignore;
  37
  38 static int __init versatile_pci_slot_ignore(char *str)
  39 {
  40         int retval;
  41         int slot;
  42
  43         while ((retval = get_option(&str, &slot))) {
  44                 if ((slot < 0) || (slot > 31))
  45                         pr_err("Illegal slot value: %d\n", slot);
  46                 else
  47                         pci_slot_ignore |= (1 << slot);
  48         }
  49         return 1;
  50 }
  51 __setup("pci_slot_ignore=", versatile_pci_slot_ignore);
  52
  53
  54 static void __iomem *versatile_map_bus(struct pci_bus *bus,
  55                                        unsigned int devfn, int offset)
  56 {
  57         unsigned int busnr = bus->number;
  58
  59         if (pci_slot_ignore & (1 << PCI_SLOT(devfn)))
  60                 return NULL;
  61
  62         return versatile_cfg_base[1] + ((busnr << 16) | (devfn << 8) | offset);
  63 }
  64
  65 static struct pci_ops pci_versatile_ops = {
  66         .map_bus = versatile_map_bus,
  67         .read   = pci_generic_config_read32,
  68         .write  = pci_generic_config_write,
  69 };
  70
  71 static int versatile_pci_parse_request_of_pci_ranges(struct device *dev,
  72                                                      struct list_head *res)
  73 {
  74         int err, mem = 1, res_valid = 0;
  75         struct device_node *np = dev->of_node;
  76         resource_size_t iobase;
  77         struct resource_entry *win, *tmp;
  78
  79         err = of_pci_get_host_bridge_resources(np, 0, 0xff, res, &iobase);
  80         if (err)
  81                 return err;
  82
  83         err = devm_request_pci_bus_resources(dev, res);
  84         if (err)
  85                 goto out_release_res;
  86
  87         resource_list_for_each_entry_safe(win, tmp, res) {
  88                 struct resource *res = win->res;
  89
  90                 switch (resource_type(res)) {
  91                 case IORESOURCE_IO:
  92                         err = devm_pci_remap_iospace(dev, res, iobase);
  93                         if (err) {
  94                                 dev_warn(dev, "error %d: failed to map resource %pR\n",
  95                                          err, res);
  96                                 resource_list_destroy_entry(win);
  97                         }
  98                         break;
  99                 case IORESOURCE_MEM:
 100                         res_valid |= !(res->flags & IORESOURCE_PREFETCH);
 101
 102                         writel(res->start >> 28, PCI_IMAP(mem));
 103                         writel(PHYS_OFFSET >> 28, PCI_SMAP(mem));
 104                         mem++;
 105
 106                         break;
 107                 }
 108         }
 109
 110         if (res_valid)
 111                 return 0;
 112
 113         dev_err(dev, "non-prefetchable memory resource required\n");
 114         err = -EINVAL;
 115
 116 out_release_res:
 117         pci_free_resource_list(res);
 118         return err;
 119 }
 120
 121 static int versatile_pci_probe(struct platform_device *pdev)
 122 {
 123         struct resource *res;
 124         int ret, i, myslot = -1;
 125         u32 val;
 126         void __iomem *local_pci_cfg_base;
 127         struct pci_bus *bus;
 128         LIST_HEAD(pci_res);
 129
 130         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 131         versatile_pci_base = devm_ioremap_resource(&pdev->dev, res);
 132         if (IS_ERR(versatile_pci_base))
 133                 return PTR_ERR(versatile_pci_base);
 134
 135         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 136         versatile_cfg_base[0] = devm_ioremap_resource(&pdev->dev, res);
 137         if (IS_ERR(versatile_cfg_base[0]))
 138                 return PTR_ERR(versatile_cfg_base[0]);
 139
 140         res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
 141         versatile_cfg_base[1] = devm_ioremap_resource(&pdev->dev, res);
 142         if (IS_ERR(versatile_cfg_base[1]))
 143                 return PTR_ERR(versatile_cfg_base[1]);
 144
 145         ret = versatile_pci_parse_request_of_pci_ranges(&pdev->dev, &pci_res);
 146         if (ret)
 147                 return ret;
 148
 149         /*
 150          * We need to discover the PCI core first to configure itself
 151          * before the main PCI probing is performed
 152          */
 153         for (i = 0; i < 32; i++) {
 154                 if ((readl(versatile_cfg_base[0] + (i << 11) + PCI_VENDOR_ID) == VP_PCI_DEVICE_ID) &&
 155                     (readl(versatile_cfg_base[0] + (i << 11) + PCI_CLASS_REVISION) == VP_PCI_CLASS_ID)) {
 156                         myslot = i;
 157                         break;
 158                 }
 159         }
 160         if (myslot == -1) {
 161                 dev_err(&pdev->dev, "Cannot find PCI core!\n");
 162                 return -EIO;
 163         }
 164         /*
 165          * Do not to map Versatile FPGA PCI device into memory space
 166          */
 167         pci_slot_ignore |= (1 << myslot);
 168
 169         dev_info(&pdev->dev, "PCI core found (slot %d)\n", myslot);
 170
 171         writel(myslot, PCI_SELFID);
 172         local_pci_cfg_base = versatile_cfg_base[1] + (myslot << 11);
 173
 174         val = readl(local_pci_cfg_base + PCI_COMMAND);
 175         val |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_INVALIDATE;
 176         writel(val, local_pci_cfg_base + PCI_COMMAND);
 177
 178         /*
 179          * Configure the PCI inbound memory windows to be 1:1 mapped to SDRAM
 180          */
 181         writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_0);
 182         writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_1);
 183         writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_2);
 184
 185         /*
 186          * For many years the kernel and QEMU were symbiotically buggy
 187          * in that they both assumed the same broken IRQ mapping.
 188          * QEMU therefore attempts to auto-detect old broken kernels
 189          * so that they still work on newer QEMU as they did on old
 190          * QEMU. Since we now use the correct (ie matching-hardware)
 191          * IRQ mapping we write a definitely different value to a
 192          * PCI_INTERRUPT_LINE register to tell QEMU that we expect
 193          * real hardware behaviour and it need not be backwards
 194          * compatible for us. This write is harmless on real hardware.
 195          */
 196         writel(0, versatile_cfg_base[0] + PCI_INTERRUPT_LINE);
 197
 198         pci_add_flags(PCI_ENABLE_PROC_DOMAINS);
 199         pci_add_flags(PCI_REASSIGN_ALL_BUS | PCI_REASSIGN_ALL_RSRC);
 200
 201         bus = pci_scan_root_bus(&pdev->dev, 0, &pci_versatile_ops, NULL, &pci_res);
 202         if (!bus)
 203                 return -ENOMEM;
 204
 205         pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
 206         pci_assign_unassigned_bus_resources(bus);
 207         pci_bus_add_devices(bus);
 208
 209         return 0;
 210 }
 211
 212 static const struct of_device_id versatile_pci_of_match[] = {
 213         { .compatible = "arm,versatile-pci", },
 214         { },
 215 };
 216 MODULE_DEVICE_TABLE(of, versatile_pci_of_match);
 217
 218 static struct platform_driver versatile_pci_driver = {
 219         .driver = {
 220                 .name = "versatile-pci",
 221                 .of_match_table = versatile_pci_of_match,
 222         },
 223         .probe = versatile_pci_probe,
 224 };
 225 module_platform_driver(versatile_pci_driver);
 226
 227 MODULE_DESCRIPTION("Versatile PCI driver");
 228 MODULE_LICENSE("GPL v2");