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;
  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(win, res) {
  88                 struct resource *res = win->res;
  89
  90                 switch (resource_type(res)) {
  91                 case IORESOURCE_IO:
  92                         err = pci_remap_iospace(res, iobase);
  93                         if (err)
  94                                 dev_warn(dev, "error %d: failed to map resource %pR\n",
  95                                          err, res);
  96                         break;
  97                 case IORESOURCE_MEM:
  98                         res_valid |= !(res->flags & IORESOURCE_PREFETCH);
  99
 100                         writel(res->start >> 28, PCI_IMAP(mem));
 101                         writel(PHYS_OFFSET >> 28, PCI_SMAP(mem));
 102                         mem++;
 103
 104                         break;
 105                 }
 106         }
 107
 108         if (res_valid)
 109                 return 0;
 110
 111         dev_err(dev, "non-prefetchable memory resource required\n");
 112         err = -EINVAL;
 113
 114 out_release_res:
 115         pci_free_resource_list(res);
 116         return err;
 117 }
 118
 119 static int versatile_pci_probe(struct platform_device *pdev)
 120 {
 121         struct resource *res;
 122         int ret, i, myslot = -1;
 123         u32 val;
 124         void __iomem *local_pci_cfg_base;
 125         struct pci_bus *bus;
 126         LIST_HEAD(pci_res);
 127
 128         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 129         versatile_pci_base = devm_ioremap_resource(&pdev->dev, res);
 130         if (IS_ERR(versatile_pci_base))
 131                 return PTR_ERR(versatile_pci_base);
 132
 133         res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
 134         versatile_cfg_base[0] = devm_ioremap_resource(&pdev->dev, res);
 135         if (IS_ERR(versatile_cfg_base[0]))
 136                 return PTR_ERR(versatile_cfg_base[0]);
 137
 138         res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
 139         versatile_cfg_base[1] = devm_ioremap_resource(&pdev->dev, res);
 140         if (IS_ERR(versatile_cfg_base[1]))
 141                 return PTR_ERR(versatile_cfg_base[1]);
 142
 143         ret = versatile_pci_parse_request_of_pci_ranges(&pdev->dev, &pci_res);
 144         if (ret)
 145                 return ret;
 146
 147         /*
 148          * We need to discover the PCI core first to configure itself
 149          * before the main PCI probing is performed
 150          */
 151         for (i = 0; i < 32; i++) {
 152                 if ((readl(versatile_cfg_base[0] + (i << 11) + PCI_VENDOR_ID) == VP_PCI_DEVICE_ID) &&
 153                     (readl(versatile_cfg_base[0] + (i << 11) + PCI_CLASS_REVISION) == VP_PCI_CLASS_ID)) {
 154                         myslot = i;
 155                         break;
 156                 }
 157         }
 158         if (myslot == -1) {
 159                 dev_err(&pdev->dev, "Cannot find PCI core!\n");
 160                 return -EIO;
 161         }
 162         /*
 163          * Do not to map Versatile FPGA PCI device into memory space
 164          */
 165         pci_slot_ignore |= (1 << myslot);
 166
 167         dev_info(&pdev->dev, "PCI core found (slot %d)\n", myslot);
 168
 169         writel(myslot, PCI_SELFID);
 170         local_pci_cfg_base = versatile_cfg_base[1] + (myslot << 11);
 171
 172         val = readl(local_pci_cfg_base + PCI_COMMAND);
 173         val |= PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | PCI_COMMAND_INVALIDATE;
 174         writel(val, local_pci_cfg_base + PCI_COMMAND);
 175
 176         /*
 177          * Configure the PCI inbound memory windows to be 1:1 mapped to SDRAM
 178          */
 179         writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_0);
 180         writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_1);
 181         writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_2);
 182
 183         /*
 184          * For many years the kernel and QEMU were symbiotically buggy
 185          * in that they both assumed the same broken IRQ mapping.
 186          * QEMU therefore attempts to auto-detect old broken kernels
 187          * so that they still work on newer QEMU as they did on old
 188          * QEMU. Since we now use the correct (ie matching-hardware)
 189          * IRQ mapping we write a definitely different value to a
 190          * PCI_INTERRUPT_LINE register to tell QEMU that we expect
 191          * real hardware behaviour and it need not be backwards
 192          * compatible for us. This write is harmless on real hardware.
 193          */
 194         writel(0, versatile_cfg_base[0] + PCI_INTERRUPT_LINE);
 195
 196         pci_add_flags(PCI_ENABLE_PROC_DOMAINS);
 197         pci_add_flags(PCI_REASSIGN_ALL_BUS | PCI_REASSIGN_ALL_RSRC);
 198
 199         bus = pci_scan_root_bus(&pdev->dev, 0, &pci_versatile_ops, NULL, &pci_res);
 200         if (!bus)
 201                 return -ENOMEM;
 202
 203         pci_fixup_irqs(pci_common_swizzle, of_irq_parse_and_map_pci);
 204         pci_assign_unassigned_bus_resources(bus);
 205         pci_bus_add_devices(bus);
 206
 207         return 0;
 208 }
 209
 210 static const struct of_device_id versatile_pci_of_match[] = {
 211         { .compatible = "arm,versatile-pci", },
 212         { },
 213 };
 214 MODULE_DEVICE_TABLE(of, versatile_pci_of_match);
 215
 216 static struct platform_driver versatile_pci_driver = {
 217         .driver = {
 218                 .name = "versatile-pci",
 219                 .of_match_table = versatile_pci_of_match,
 220         },
 221         .probe = versatile_pci_probe,
 222 };
 223 module_platform_driver(versatile_pci_driver);
 224
 225 MODULE_DESCRIPTION("Versatile PCI driver");
 226 MODULE_LICENSE("GPL v2");