linux/arch/powerpc/kernel/pci_of_scan.c
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   1/*
   2 * Helper routines to scan the device tree for PCI devices and busses
   3 *
   4 * Migrated out of PowerPC architecture pci_64.c file by Grant Likely
   5 * <grant.likely@secretlab.ca> so that these routines are available for
   6 * 32 bit also.
   7 *
   8 * Copyright (C) 2003 Anton Blanchard <anton@au.ibm.com>, IBM
   9 *   Rework, based on alpha PCI code.
  10 * Copyright (c) 2009 Secret Lab Technologies Ltd.
  11 *
  12 * This program is free software; you can redistribute it and/or
  13 * modify it under the terms of the GNU General Public License
  14 * version 2 as published by the Free Software Foundation.
  15 */
  16
  17#include <linux/pci.h>
  18#include <asm/pci-bridge.h>
  19#include <asm/prom.h>
  20
  21/**
  22 * get_int_prop - Decode a u32 from a device tree property
  23 */
  24static u32 get_int_prop(struct device_node *np, const char *name, u32 def)
  25{
  26        const u32 *prop;
  27        int len;
  28
  29        prop = of_get_property(np, name, &len);
  30        if (prop && len >= 4)
  31                return *prop;
  32        return def;
  33}
  34
  35/**
  36 * pci_parse_of_flags - Parse the flags cell of a device tree PCI address
  37 * @addr0: value of 1st cell of a device tree PCI address.
  38 * @bridge: Set this flag if the address is from a bridge 'ranges' property
  39 */
  40unsigned int pci_parse_of_flags(u32 addr0, int bridge)
  41{
  42        unsigned int flags = 0;
  43
  44        if (addr0 & 0x02000000) {
  45                flags = IORESOURCE_MEM | PCI_BASE_ADDRESS_SPACE_MEMORY;
  46                flags |= (addr0 >> 22) & PCI_BASE_ADDRESS_MEM_TYPE_64;
  47                flags |= (addr0 >> 28) & PCI_BASE_ADDRESS_MEM_TYPE_1M;
  48                if (addr0 & 0x40000000)
  49                        flags |= IORESOURCE_PREFETCH
  50                                 | PCI_BASE_ADDRESS_MEM_PREFETCH;
  51                /* Note: We don't know whether the ROM has been left enabled
  52                 * by the firmware or not. We mark it as disabled (ie, we do
  53                 * not set the IORESOURCE_ROM_ENABLE flag) for now rather than
  54                 * do a config space read, it will be force-enabled if needed
  55                 */
  56                if (!bridge && (addr0 & 0xff) == 0x30)
  57                        flags |= IORESOURCE_READONLY;
  58        } else if (addr0 & 0x01000000)
  59                flags = IORESOURCE_IO | PCI_BASE_ADDRESS_SPACE_IO;
  60        if (flags)
  61                flags |= IORESOURCE_SIZEALIGN;
  62        return flags;
  63}
  64
  65/**
  66 * of_pci_parse_addrs - Parse PCI addresses assigned in the device tree node
  67 * @node: device tree node for the PCI device
  68 * @dev: pci_dev structure for the device
  69 *
  70 * This function parses the 'assigned-addresses' property of a PCI devices'
  71 * device tree node and writes them into the associated pci_dev structure.
  72 */
  73static void of_pci_parse_addrs(struct device_node *node, struct pci_dev *dev)
  74{
  75        u64 base, size;
  76        unsigned int flags;
  77        struct resource *res;
  78        const u32 *addrs;
  79        u32 i;
  80        int proplen;
  81
  82        addrs = of_get_property(node, "assigned-addresses", &proplen);
  83        if (!addrs)
  84                return;
  85        pr_debug("    parse addresses (%d bytes) @ %p\n", proplen, addrs);
  86        for (; proplen >= 20; proplen -= 20, addrs += 5) {
  87                flags = pci_parse_of_flags(addrs[0], 0);
  88                if (!flags)
  89                        continue;
  90                base = of_read_number(&addrs[1], 2);
  91                size = of_read_number(&addrs[3], 2);
  92                if (!size)
  93                        continue;
  94                i = addrs[0] & 0xff;
  95                pr_debug("  base: %llx, size: %llx, i: %x\n",
  96                         (unsigned long long)base,
  97                         (unsigned long long)size, i);
  98
  99                if (PCI_BASE_ADDRESS_0 <= i && i <= PCI_BASE_ADDRESS_5) {
 100                        res = &dev->resource[(i - PCI_BASE_ADDRESS_0) >> 2];
 101                } else if (i == dev->rom_base_reg) {
 102                        res = &dev->resource[PCI_ROM_RESOURCE];
 103                        flags |= IORESOURCE_READONLY | IORESOURCE_CACHEABLE;
 104                } else {
 105                        printk(KERN_ERR "PCI: bad cfg reg num 0x%x\n", i);
 106                        continue;
 107                }
 108                res->start = base;
 109                res->end = base + size - 1;
 110                res->flags = flags;
 111                res->name = pci_name(dev);
 112        }
 113}
 114
 115/**
 116 * of_create_pci_dev - Given a device tree node on a pci bus, create a pci_dev
 117 * @node: device tree node pointer
 118 * @bus: bus the device is sitting on
 119 * @devfn: PCI function number, extracted from device tree by caller.
 120 */
 121struct pci_dev *of_create_pci_dev(struct device_node *node,
 122                                 struct pci_bus *bus, int devfn)
 123{
 124        struct pci_dev *dev;
 125        const char *type;
 126        struct pci_slot *slot;
 127
 128        dev = alloc_pci_dev();
 129        if (!dev)
 130                return NULL;
 131        type = of_get_property(node, "device_type", NULL);
 132        if (type == NULL)
 133                type = "";
 134
 135        pr_debug("    create device, devfn: %x, type: %s\n", devfn, type);
 136
 137        dev->bus = bus;
 138        dev->dev.of_node = of_node_get(node);
 139        dev->dev.parent = bus->bridge;
 140        dev->dev.bus = &pci_bus_type;
 141        dev->devfn = devfn;
 142        dev->multifunction = 0;         /* maybe a lie? */
 143        dev->needs_freset = 0;          /* pcie fundamental reset required */
 144        set_pcie_port_type(dev);
 145
 146        list_for_each_entry(slot, &dev->bus->slots, list)
 147                if (PCI_SLOT(dev->devfn) == slot->number)
 148                        dev->slot = slot;
 149
 150        dev->vendor = get_int_prop(node, "vendor-id", 0xffff);
 151        dev->device = get_int_prop(node, "device-id", 0xffff);
 152        dev->subsystem_vendor = get_int_prop(node, "subsystem-vendor-id", 0);
 153        dev->subsystem_device = get_int_prop(node, "subsystem-id", 0);
 154
 155        dev->cfg_size = pci_cfg_space_size(dev);
 156
 157        dev_set_name(&dev->dev, "%04x:%02x:%02x.%d", pci_domain_nr(bus),
 158                dev->bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn));
 159        dev->class = get_int_prop(node, "class-code", 0);
 160        dev->revision = get_int_prop(node, "revision-id", 0);
 161
 162        pr_debug("    class: 0x%x\n", dev->class);
 163        pr_debug("    revision: 0x%x\n", dev->revision);
 164
 165        dev->current_state = 4;         /* unknown power state */
 166        dev->error_state = pci_channel_io_normal;
 167        dev->dma_mask = 0xffffffff;
 168
 169        /* Early fixups, before probing the BARs */
 170        pci_fixup_device(pci_fixup_early, dev);
 171
 172        if (!strcmp(type, "pci") || !strcmp(type, "pciex")) {
 173                /* a PCI-PCI bridge */
 174                dev->hdr_type = PCI_HEADER_TYPE_BRIDGE;
 175                dev->rom_base_reg = PCI_ROM_ADDRESS1;
 176                set_pcie_hotplug_bridge(dev);
 177        } else if (!strcmp(type, "cardbus")) {
 178                dev->hdr_type = PCI_HEADER_TYPE_CARDBUS;
 179        } else {
 180                dev->hdr_type = PCI_HEADER_TYPE_NORMAL;
 181                dev->rom_base_reg = PCI_ROM_ADDRESS;
 182                /* Maybe do a default OF mapping here */
 183                dev->irq = NO_IRQ;
 184        }
 185
 186        of_pci_parse_addrs(node, dev);
 187
 188        pr_debug("    adding to system ...\n");
 189
 190        pci_device_add(dev, bus);
 191
 192        return dev;
 193}
 194EXPORT_SYMBOL(of_create_pci_dev);
 195
 196/**
 197 * of_scan_pci_bridge - Set up a PCI bridge and scan for child nodes
 198 * @node: device tree node of bridge
 199 * @dev: pci_dev structure for the bridge
 200 *
 201 * of_scan_bus() calls this routine for each PCI bridge that it finds, and
 202 * this routine in turn call of_scan_bus() recusively to scan for more child
 203 * devices.
 204 */
 205void __devinit of_scan_pci_bridge(struct device_node *node,
 206                                  struct pci_dev *dev)
 207{
 208        struct pci_bus *bus;
 209        const u32 *busrange, *ranges;
 210        int len, i, mode;
 211        struct resource *res;
 212        unsigned int flags;
 213        u64 size;
 214
 215        pr_debug("of_scan_pci_bridge(%s)\n", node->full_name);
 216
 217        /* parse bus-range property */
 218        busrange = of_get_property(node, "bus-range", &len);
 219        if (busrange == NULL || len != 8) {
 220                printk(KERN_DEBUG "Can't get bus-range for PCI-PCI bridge %s\n",
 221                       node->full_name);
 222                return;
 223        }
 224        ranges = of_get_property(node, "ranges", &len);
 225        if (ranges == NULL) {
 226                printk(KERN_DEBUG "Can't get ranges for PCI-PCI bridge %s\n",
 227                       node->full_name);
 228                return;
 229        }
 230
 231        bus = pci_add_new_bus(dev->bus, dev, busrange[0]);
 232        if (!bus) {
 233                printk(KERN_ERR "Failed to create pci bus for %s\n",
 234                       node->full_name);
 235                return;
 236        }
 237
 238        bus->primary = dev->bus->number;
 239        bus->subordinate = busrange[1];
 240        bus->bridge_ctl = 0;
 241        bus->dev.of_node = of_node_get(node);
 242
 243        /* parse ranges property */
 244        /* PCI #address-cells == 3 and #size-cells == 2 always */
 245        res = &dev->resource[PCI_BRIDGE_RESOURCES];
 246        for (i = 0; i < PCI_NUM_RESOURCES - PCI_BRIDGE_RESOURCES; ++i) {
 247                res->flags = 0;
 248                bus->resource[i] = res;
 249                ++res;
 250        }
 251        i = 1;
 252        for (; len >= 32; len -= 32, ranges += 8) {
 253                flags = pci_parse_of_flags(ranges[0], 1);
 254                size = of_read_number(&ranges[6], 2);
 255                if (flags == 0 || size == 0)
 256                        continue;
 257                if (flags & IORESOURCE_IO) {
 258                        res = bus->resource[0];
 259                        if (res->flags) {
 260                                printk(KERN_ERR "PCI: ignoring extra I/O range"
 261                                       " for bridge %s\n", node->full_name);
 262                                continue;
 263                        }
 264                } else {
 265                        if (i >= PCI_NUM_RESOURCES - PCI_BRIDGE_RESOURCES) {
 266                                printk(KERN_ERR "PCI: too many memory ranges"
 267                                       " for bridge %s\n", node->full_name);
 268                                continue;
 269                        }
 270                        res = bus->resource[i];
 271                        ++i;
 272                }
 273                res->start = of_read_number(&ranges[1], 2);
 274                res->end = res->start + size - 1;
 275                res->flags = flags;
 276        }
 277        sprintf(bus->name, "PCI Bus %04x:%02x", pci_domain_nr(bus),
 278                bus->number);
 279        pr_debug("    bus name: %s\n", bus->name);
 280
 281        mode = PCI_PROBE_NORMAL;
 282        if (ppc_md.pci_probe_mode)
 283                mode = ppc_md.pci_probe_mode(bus);
 284        pr_debug("    probe mode: %d\n", mode);
 285
 286        if (mode == PCI_PROBE_DEVTREE)
 287                of_scan_bus(node, bus);
 288        else if (mode == PCI_PROBE_NORMAL)
 289                pci_scan_child_bus(bus);
 290}
 291EXPORT_SYMBOL(of_scan_pci_bridge);
 292
 293/**
 294 * __of_scan_bus - given a PCI bus node, setup bus and scan for child devices
 295 * @node: device tree node for the PCI bus
 296 * @bus: pci_bus structure for the PCI bus
 297 * @rescan_existing: Flag indicating bus has already been set up
 298 */
 299static void __devinit __of_scan_bus(struct device_node *node,
 300                                    struct pci_bus *bus, int rescan_existing)
 301{
 302        struct device_node *child;
 303        const u32 *reg;
 304        int reglen, devfn;
 305        struct pci_dev *dev;
 306
 307        pr_debug("of_scan_bus(%s) bus no %d...\n",
 308                 node->full_name, bus->number);
 309
 310        /* Scan direct children */
 311        for_each_child_of_node(node, child) {
 312                pr_debug("  * %s\n", child->full_name);
 313                if (!of_device_is_available(child))
 314                        continue;
 315                reg = of_get_property(child, "reg", &reglen);
 316                if (reg == NULL || reglen < 20)
 317                        continue;
 318                devfn = (reg[0] >> 8) & 0xff;
 319
 320                /* create a new pci_dev for this device */
 321                dev = of_create_pci_dev(child, bus, devfn);
 322                if (!dev)
 323                        continue;
 324                pr_debug("    dev header type: %x\n", dev->hdr_type);
 325        }
 326
 327        /* Apply all fixups necessary. We don't fixup the bus "self"
 328         * for an existing bridge that is being rescanned
 329         */
 330        if (!rescan_existing)
 331                pcibios_setup_bus_self(bus);
 332        pcibios_setup_bus_devices(bus);
 333
 334        /* Now scan child busses */
 335        list_for_each_entry(dev, &bus->devices, bus_list) {
 336                if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE ||
 337                    dev->hdr_type == PCI_HEADER_TYPE_CARDBUS) {
 338                        struct device_node *child = pci_device_to_OF_node(dev);
 339                        if (child)
 340                                of_scan_pci_bridge(child, dev);
 341                }
 342        }
 343}
 344
 345/**
 346 * of_scan_bus - given a PCI bus node, setup bus and scan for child devices
 347 * @node: device tree node for the PCI bus
 348 * @bus: pci_bus structure for the PCI bus
 349 */
 350void __devinit of_scan_bus(struct device_node *node,
 351                           struct pci_bus *bus)
 352{
 353        __of_scan_bus(node, bus, 0);
 354}
 355EXPORT_SYMBOL_GPL(of_scan_bus);
 356
 357/**
 358 * of_rescan_bus - given a PCI bus node, scan for child devices
 359 * @node: device tree node for the PCI bus
 360 * @bus: pci_bus structure for the PCI bus
 361 *
 362 * Same as of_scan_bus, but for a pci_bus structure that has already been
 363 * setup.
 364 */
 365void __devinit of_rescan_bus(struct device_node *node,
 366                             struct pci_bus *bus)
 367{
 368        __of_scan_bus(node, bus, 1);
 369}
 370EXPORT_SYMBOL_GPL(of_rescan_bus);
 371
 372