#undef DEBUG

#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/pci_regs.h>
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/etherdevice.h>
#include <asm/prom.h>
#include <asm/pci-bridge.h>

#ifdef DEBUG
#define DBG(fmt...) do { printk(fmt); } while(0)
#else
#define DBG(fmt...) do { } while(0)
#endif

#ifdef CONFIG_PPC64
#define PRu64   "%lx"
#else
#define PRu64   "%llx"
#endif

/* Max address size we deal with */
#define OF_MAX_ADDR_CELLS       4
#define OF_CHECK_COUNTS(na, ns) ((na) > 0 && (na) <= OF_MAX_ADDR_CELLS && \
                        (ns) > 0)

static struct of_bus *of_match_bus(struct device_node *np);
static int __of_address_to_resource(struct device_node *dev,
                const u32 *addrp, u64 size, unsigned int flags,
                struct resource *r);


/* Debug utility */
#ifdef DEBUG
static void of_dump_addr(const char *s, const u32 *addr, int na)
{
        printk("%s", s);
        while(na--)
                printk(" %08x", *(addr++));
        printk("\n");
}
#else
static void of_dump_addr(const char *s, const u32 *addr, int na) { }
#endif


/* Callbacks for bus specific translators */
struct of_bus {
        const char      *name;
        const char      *addresses;
        int             (*match)(struct device_node *parent);
        void            (*count_cells)(struct device_node *child,
                                       int *addrc, int *sizec);
        u64             (*map)(u32 *addr, const u32 *range,
                                int na, int ns, int pna);
        int             (*translate)(u32 *addr, u64 offset, int na);
        unsigned int    (*get_flags)(const u32 *addr);
};


/*
 * Default translator (generic bus)
 */

static void of_bus_default_count_cells(struct device_node *dev,
                                       int *addrc, int *sizec)
{
        if (addrc)
                *addrc = of_n_addr_cells(dev);
        if (sizec)
                *sizec = of_n_size_cells(dev);
}

static u64 of_bus_default_map(u32 *addr, const u32 *range,
                int na, int ns, int pna)
{
        u64 cp, s, da;

        cp = of_read_number(range, na);
        s  = of_read_number(range + na + pna, ns);
        da = of_read_number(addr, na);

        DBG("OF: default map, cp="PRu64", s="PRu64", da="PRu64"\n",
            cp, s, da);

        if (da < cp || da >= (cp + s))
                return OF_BAD_ADDR;
        return da - cp;
}

static int of_bus_default_translate(u32 *addr, u64 offset, int na)
{
        u64 a = of_read_number(addr, na);
        memset(addr, 0, na * 4);
        a += offset;
        if (na > 1)
                addr[na - 2] = a >> 32;
        addr[na - 1] = a & 0xffffffffu;

        return 0;
}

static unsigned int of_bus_default_get_flags(const u32 *addr)
{
        return IORESOURCE_MEM;
}


#ifdef CONFIG_PCI
/*
 * PCI bus specific translator
 */

static int of_bus_pci_match(struct device_node *np)
{
        /* "vci" is for the /chaos bridge on 1st-gen PCI powermacs */
        return !strcmp(np->type, "pci") || !strcmp(np->type, "vci");
}

static void of_bus_pci_count_cells(struct device_node *np,
                                   int *addrc, int *sizec)
{
        if (addrc)
                *addrc = 3;
        if (sizec)
                *sizec = 2;
}

static unsigned int of_bus_pci_get_flags(const u32 *addr)
{
        unsigned int flags = 0;
        u32 w = addr[0];

        switch((w >> 24) & 0x03) {
        case 0x01:
                flags |= IORESOURCE_IO;
                break;
        case 0x02: /* 32 bits */
        case 0x03: /* 64 bits */
                flags |= IORESOURCE_MEM;
                break;
        }
        if (w & 0x40000000)
                flags |= IORESOURCE_PREFETCH;
        return flags;
}

static u64 of_bus_pci_map(u32 *addr, const u32 *range, int na, int ns, int pna)
{
        u64 cp, s, da;
        unsigned int af, rf;

        af = of_bus_pci_get_flags(addr);
        rf = of_bus_pci_get_flags(range);

        /* Check address type match */
        if ((af ^ rf) & (IORESOURCE_MEM | IORESOURCE_IO))
                return OF_BAD_ADDR;

        /* Read address values, skipping high cell */
        cp = of_read_number(range + 1, na - 1);
        s  = of_read_number(range + na + pna, ns);
        da = of_read_number(addr + 1, na - 1);

        DBG("OF: PCI map, cp="PRu64", s="PRu64", da="PRu64"\n", cp, s, da);

        if (da < cp || da >= (cp + s))
                return OF_BAD_ADDR;
        return da - cp;
}

static int of_bus_pci_translate(u32 *addr, u64 offset, int na)
{
        return of_bus_default_translate(addr + 1, offset, na - 1);
}

const u32 *of_get_pci_address(struct device_node *dev, int bar_no, u64 *size,
                        unsigned int *flags)
{
        const u32 *prop;
        unsigned int psize;
        struct device_node *parent;
        struct of_bus *bus;
        int onesize, i, na, ns;

        /* Get parent & match bus type */
        parent = of_get_parent(dev);
        if (parent == NULL)
                return NULL;
        bus = of_match_bus(parent);
        if (strcmp(bus->name, "pci")) {
                of_node_put(parent);
                return NULL;
        }
        bus->count_cells(dev, &na, &ns);
        of_node_put(parent);
        if (!OF_CHECK_COUNTS(na, ns))
                return NULL;

        /* Get "reg" or "assigned-addresses" property */
        prop = of_get_property(dev, bus->addresses, &psize);
        if (prop == NULL)
                return NULL;
        psize /= 4;

        onesize = na + ns;
        for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++)
                if ((prop[0] & 0xff) == ((bar_no * 4) + PCI_BASE_ADDRESS_0)) {
                        if (size)
                                *size = of_read_number(prop + na, ns);
                        if (flags)
                                *flags = bus->get_flags(prop);
                        return prop;
                }
        return NULL;
}
EXPORT_SYMBOL(of_get_pci_address);

int of_pci_address_to_resource(struct device_node *dev, int bar,
                               struct resource *r)
{
        const u32       *addrp;
        u64             size;
        unsigned int    flags;

        addrp = of_get_pci_address(dev, bar, &size, &flags);
        if (addrp == NULL)
                return -EINVAL;
        return __of_address_to_resource(dev, addrp, size, flags, r);
}
EXPORT_SYMBOL_GPL(of_pci_address_to_resource);

int of_irq_map_pci(struct pci_dev *pdev, struct of_irq *out_irq)
{
        struct device_node *dn, *ppnode;
        struct pci_dev *ppdev;
        u32 lspec;
        u32 laddr[3];
        u8 pin;
        int rc;

        /* Check if we have a device node, if yes, fallback to standard OF
         * parsing
         */
        dn = pci_device_to_OF_node(pdev);
        if (dn) {
                rc = of_irq_map_one(dn, 0, out_irq);
                if (!rc)
                        return rc;
        }

        /* Ok, we don't, time to have fun. Let's start by building up an
         * interrupt spec.  we assume #interrupt-cells is 1, which is standard
         * for PCI. If you do different, then don't use that routine.
         */
        rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
        if (rc != 0)
                return rc;
        /* No pin, exit */
        if (pin == 0)
                return -ENODEV;

        /* Now we walk up the PCI tree */
        lspec = pin;
        for (;;) {
                /* Get the pci_dev of our parent */
                ppdev = pdev->bus->self;

                /* Ouch, it's a host bridge... */
                if (ppdev == NULL) {
#ifdef CONFIG_PPC64
                        ppnode = pci_bus_to_OF_node(pdev->bus);
#else
                        struct pci_controller *host;
                        host = pci_bus_to_host(pdev->bus);
                        ppnode = host ? host->dn : NULL;
#endif
                        /* No node for host bridge ? give up */
                        if (ppnode == NULL)
                                return -EINVAL;
                } else
                        /* We found a P2P bridge, check if it has a node */
                        ppnode = pci_device_to_OF_node(ppdev);

                /* Ok, we have found a parent with a device-node, hand over to
                 * the OF parsing code.
                 * We build a unit address from the linux device to be used for
                 * resolution. Note that we use the linux bus number which may
                 * not match your firmware bus numbering.
                 * Fortunately, in most cases, interrupt-map-mask doesn't include
                 * the bus number as part of the matching.
                 * You should still be careful about that though if you intend
                 * to rely on this function (you ship  a firmware that doesn't
                 * create device nodes for all PCI devices).
                 */
                if (ppnode)
                        break;

                /* We can only get here if we hit a P2P bridge with no node,
                 * let's do standard swizzling and try again
                 */
                lspec = pci_swizzle_interrupt_pin(pdev, lspec);
                pdev = ppdev;
        }

        laddr[0] = (pdev->bus->number << 16)
                | (pdev->devfn << 8);
        laddr[1]  = laddr[2] = 0;
        return of_irq_map_raw(ppnode, &lspec, 1, laddr, out_irq);
}
EXPORT_SYMBOL_GPL(of_irq_map_pci);
#endif /* CONFIG_PCI */

/*
 * ISA bus specific translator
 */

static int of_bus_isa_match(struct device_node *np)
{
        return !strcmp(np->name, "isa");
}

static void of_bus_isa_count_cells(struct device_node *child,
                                   int *addrc, int *sizec)
{
        if (addrc)
                *addrc = 2;
        if (sizec)
                *sizec = 1;
}

static u64 of_bus_isa_map(u32 *addr, const u32 *range, int na, int ns, int pna)
{
        u64 cp, s, da;

        /* Check address type match */
        if ((addr[0] ^ range[0]) & 0x00000001)
                return OF_BAD_ADDR;

        /* Read address values, skipping high cell */
        cp = of_read_number(range + 1, na - 1);
        s  = of_read_number(range + na + pna, ns);
        da = of_read_number(addr + 1, na - 1);

        DBG("OF: ISA map, cp="PRu64", s="PRu64", da="PRu64"\n", cp, s, da);

        if (da < cp || da >= (cp + s))
                return OF_BAD_ADDR;
        return da - cp;
}

static int of_bus_isa_translate(u32 *addr, u64 offset, int na)
{
        return of_bus_default_translate(addr + 1, offset, na - 1);
}

static unsigned int of_bus_isa_get_flags(const u32 *addr)
{
        unsigned int flags = 0;
        u32 w = addr[0];

        if (w & 1)
                flags |= IORESOURCE_IO;
        else
                flags |= IORESOURCE_MEM;
        return flags;
}


/*
 * Array of bus specific translators
 */

static struct of_bus of_busses[] = {
#ifdef CONFIG_PCI
        /* PCI */
        {
                .name = "pci",
                .addresses = "assigned-addresses",
                .match = of_bus_pci_match,
                .count_cells = of_bus_pci_count_cells,
                .map = of_bus_pci_map,
                .translate = of_bus_pci_translate,
                .get_flags = of_bus_pci_get_flags,
        },
#endif /* CONFIG_PCI */
        /* ISA */
        {
                .name = "isa",
                .addresses = "reg",
                .match = of_bus_isa_match,
                .count_cells = of_bus_isa_count_cells,
                .map = of_bus_isa_map,
                .translate = of_bus_isa_translate,
                .get_flags = of_bus_isa_get_flags,
        },
        /* Default */
        {
                .name = "default",
                .addresses = "reg",
                .match = NULL,
                .count_cells = of_bus_default_count_cells,
                .map = of_bus_default_map,
                .translate = of_bus_default_translate,
                .get_flags = of_bus_default_get_flags,
        },
};

static struct of_bus *of_match_bus(struct device_node *np)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(of_busses); i ++)
                if (!of_busses[i].match || of_busses[i].match(np))
                        return &of_busses[i];
        BUG();
        return NULL;
}

static int of_translate_one(struct device_node *parent, struct of_bus *bus,
                            struct of_bus *pbus, u32 *addr,
                            int na, int ns, int pna, const char *rprop)
{
        const u32 *ranges;
        unsigned int rlen;
        int rone;
        u64 offset = OF_BAD_ADDR;

        /* Normally, an absence of a "ranges" property means we are
         * crossing a non-translatable boundary, and thus the addresses
         * below the current not cannot be converted to CPU physical ones.
         * Unfortunately, while this is very clear in the spec, it's not
         * what Apple understood, and they do have things like /uni-n or
         * /ht nodes with no "ranges" property and a lot of perfectly
         * useable mapped devices below them. Thus we treat the absence of
         * "ranges" as equivalent to an empty "ranges" property which means
         * a 1:1 translation at that level. It's up to the caller not to try
         * to translate addresses that aren't supposed to be translated in
         * the first place. --BenH.
         */
        ranges = of_get_property(parent, rprop, &rlen);
        if (ranges == NULL || rlen == 0) {
                offset = of_read_number(addr, na);
                memset(addr, 0, pna * 4);
                DBG("OF: no ranges, 1:1 translation\n");
                goto finish;
        }

        DBG("OF: walking ranges...\n");

        /* Now walk through the ranges */
        rlen /= 4;
        rone = na + pna + ns;
        for (; rlen >= rone; rlen -= rone, ranges += rone) {
                offset = bus->map(addr, ranges, na, ns, pna);
                if (offset != OF_BAD_ADDR)
                        break;
        }
        if (offset == OF_BAD_ADDR) {
                DBG("OF: not found !\n");
                return 1;
        }
        memcpy(addr, ranges + na, 4 * pna);

 finish:
        of_dump_addr("OF: parent translation for:", addr, pna);
        DBG("OF: with offset: "PRu64"\n", offset);

        /* Translate it into parent bus space */
        return pbus->translate(addr, offset, pna);
}


/*
 * Translate an address from the device-tree into a CPU physical address,
 * this walks up the tree and applies the various bus mappings on the
 * way.
 *
 * Note: We consider that crossing any level with #size-cells == 0 to mean
 * that translation is impossible (that is we are not dealing with a value
 * that can be mapped to a cpu physical address). This is not really specified
 * that way, but this is traditionally the way IBM at least do things
 */
u64 __of_translate_address(struct device_node *dev, const u32 *in_addr,
                           const char *rprop)
{
        struct device_node *parent = NULL;
        struct of_bus *bus, *pbus;
        u32 addr[OF_MAX_ADDR_CELLS];
        int na, ns, pna, pns;
        u64 result = OF_BAD_ADDR;

        DBG("OF: ** translation for device %s **\n", dev->full_name);

        /* Increase refcount at current level */
        of_node_get(dev);

        /* Get parent & match bus type */
        parent = of_get_parent(dev);
        if (parent == NULL)
                goto bail;
        bus = of_match_bus(parent);

        /* Cound address cells & copy address locally */
        bus->count_cells(dev, &na, &ns);
        if (!OF_CHECK_COUNTS(na, ns)) {
                printk(KERN_ERR "prom_parse: Bad cell count for %s\n",
                       dev->full_name);
                goto bail;
        }
        memcpy(addr, in_addr, na * 4);

        DBG("OF: bus is %s (na=%d, ns=%d) on %s\n",
            bus->name, na, ns, parent->full_name);
        of_dump_addr("OF: translating address:", addr, na);

        /* Translate */
        for (;;) {
                /* Switch to parent bus */
                of_node_put(dev);
                dev = parent;
                parent = of_get_parent(dev);

                /* If root, we have finished */
                if (parent == NULL) {
                        DBG("OF: reached root node\n");
                        result = of_read_number(addr, na);
                        break;
                }

                /* Get new parent bus and counts */
                pbus = of_match_bus(parent);
                pbus->count_cells(dev, &pna, &pns);
                if (!OF_CHECK_COUNTS(pna, pns)) {
                        printk(KERN_ERR "prom_parse: Bad cell count for %s\n",
                               dev->full_name);
                        break;
                }

                DBG("OF: parent bus is %s (na=%d, ns=%d) on %s\n",
                    pbus->name, pna, pns, parent->full_name);

                /* Apply bus translation */
                if (of_translate_one(dev, bus, pbus, addr, na, ns, pna, rprop))
                        break;

                /* Complete the move up one level */
                na = pna;
                ns = pns;
                bus = pbus;

                of_dump_addr("OF: one level translation:", addr, na);
        }
 bail:
        of_node_put(parent);
        of_node_put(dev);

        return result;
}

u64 of_translate_address(struct device_node *dev, const u32 *in_addr)
{
        return __of_translate_address(dev, in_addr, "ranges");
}
EXPORT_SYMBOL(of_translate_address);

u64 of_translate_dma_address(struct device_node *dev, const u32 *in_addr)
{
        return __of_translate_address(dev, in_addr, "dma-ranges");
}
EXPORT_SYMBOL(of_translate_dma_address);

const u32 *of_get_address(struct device_node *dev, int index, u64 *size,
                    unsigned int *flags)
{
        const u32 *prop;
        unsigned int psize;
        struct device_node *parent;
        struct of_bus *bus;
        int onesize, i, na, ns;

        /* Get parent & match bus type */
        parent = of_get_parent(dev);
        if (parent == NULL)
                return NULL;
        bus = of_match_bus(parent);
        bus->count_cells(dev, &na, &ns);
        of_node_put(parent);
        if (!OF_CHECK_COUNTS(na, ns))
                return NULL;

        /* Get "reg" or "assigned-addresses" property */
        prop = of_get_property(dev, bus->addresses, &psize);
        if (prop == NULL)
                return NULL;
        psize /= 4;

        onesize = na + ns;
        for (i = 0; psize >= onesize; psize -= onesize, prop += onesize, i++)
                if (i == index) {
                        if (size)
                                *size = of_read_number(prop + na, ns);
                        if (flags)
                                *flags = bus->get_flags(prop);
                        return prop;
                }
        return NULL;
}
EXPORT_SYMBOL(of_get_address);

static int __of_address_to_resource(struct device_node *dev, const u32 *addrp,
                                    u64 size, unsigned int flags,
                                    struct resource *r)
{
        u64 taddr;

        if ((flags & (IORESOURCE_IO | IORESOURCE_MEM)) == 0)
                return -EINVAL;
        taddr = of_translate_address(dev, addrp);
        if (taddr == OF_BAD_ADDR)
                return -EINVAL;
        memset(r, 0, sizeof(struct resource));
        if (flags & IORESOURCE_IO) {
                unsigned long port;
                port = pci_address_to_pio(taddr);
                if (port == (unsigned long)-1)
                        return -EINVAL;
                r->start = port;
                r->end = port + size - 1;
        } else {
                r->start = taddr;
                r->end = taddr + size - 1;
        }
        r->flags = flags;
        r->name = dev->name;
        return 0;
}

int of_address_to_resource(struct device_node *dev, int index,
                           struct resource *r)
{
        const u32       *addrp;
        u64             size;
        unsigned int    flags;

        addrp = of_get_address(dev, index, &size, &flags);
        if (addrp == NULL)
                return -EINVAL;
        return __of_address_to_resource(dev, addrp, size, flags, r);
}
EXPORT_SYMBOL_GPL(of_address_to_resource);

void of_parse_dma_window(struct device_node *dn, const void *dma_window_prop,
                unsigned long *busno, unsigned long *phys, unsigned long *size)
{
        const u32 *dma_window;
        u32 cells;
        const unsigned char *prop;

        dma_window = dma_window_prop;

        /* busno is always one cell */
        *busno = *(dma_window++);

        prop = of_get_property(dn, "ibm,#dma-address-cells", NULL);
        if (!prop)
                prop = of_get_property(dn, "#address-cells", NULL);

        cells = prop ? *(u32 *)prop : of_n_addr_cells(dn);
        *phys = of_read_number(dma_window, cells);

        dma_window += cells;

        prop = of_get_property(dn, "ibm,#dma-size-cells", NULL);
        cells = prop ? *(u32 *)prop : of_n_size_cells(dn);
        *size = of_read_number(dma_window, cells);
}

/*
 * Interrupt remapper
 */

static unsigned int of_irq_workarounds;
static struct device_node *of_irq_dflt_pic;

static struct device_node *of_irq_find_parent(struct device_node *child)
{
        struct device_node *p;
        const phandle *parp;

        if (!of_node_get(child))
                return NULL;

        do {
                parp = of_get_property(child, "interrupt-parent", NULL);
                if (parp == NULL)
                        p = of_get_parent(child);
                else {
                        if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
                                p = of_node_get(of_irq_dflt_pic);
                        else
                                p = of_find_node_by_phandle(*parp);
                }
                of_node_put(child);
                child = p;
        } while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL);

        return p;
}

/* This doesn't need to be called if you don't have any special workaround
 * flags to pass
 */
void of_irq_map_init(unsigned int flags)
{
        of_irq_workarounds = flags;

        /* OldWorld, don't bother looking at other things */
        if (flags & OF_IMAP_OLDWORLD_MAC)
                return;

        /* If we don't have phandles, let's try to locate a default interrupt
         * controller (happens when booting with BootX). We do a first match
         * here, hopefully, that only ever happens on machines with one
         * controller.
         */
        if (flags & OF_IMAP_NO_PHANDLE) {
                struct device_node *np;

                for_each_node_with_property(np, "interrupt-controller") {
                        /* Skip /chosen/interrupt-controller */
                        if (strcmp(np->name, "chosen") == 0)
                                continue;
                        /* It seems like at least one person on this planet wants
                         * to use BootX on a machine with an AppleKiwi controller
                         * which happens to pretend to be an interrupt
                         * controller too.
                         */
                        if (strcmp(np->name, "AppleKiwi") == 0)
                                continue;
                        /* I think we found one ! */
                        of_irq_dflt_pic = np;
                        break;
                }
        }

}

int of_irq_map_raw(struct device_node *parent, const u32 *intspec, u32 ointsize,
                const u32 *addr, struct of_irq *out_irq)
{
        struct device_node *ipar, *tnode, *old = NULL, *newpar = NULL;
        const u32 *tmp, *imap, *imask;
        u32 intsize = 1, addrsize, newintsize = 0, newaddrsize = 0;
        int imaplen, match, i;

        DBG("of_irq_map_raw: par=%s,intspec=[0x%08x 0x%08x...],ointsize=%d\n",
            parent->full_name, intspec[0], intspec[1], ointsize);

        ipar = of_node_get(parent);

        /* First get the #interrupt-cells property of the current cursor
         * that tells us how to interpret the passed-in intspec. If there
         * is none, we are nice and just walk up the tree
         */
        do {
                tmp = of_get_property(ipar, "#interrupt-cells", NULL);
                if (tmp != NULL) {
                        intsize = *tmp;
                        break;
                }
                tnode = ipar;
                ipar = of_irq_find_parent(ipar);
                of_node_put(tnode);
        } while (ipar);
        if (ipar == NULL) {
                DBG(" -> no parent found !\n");
                goto fail;
        }

        DBG("of_irq_map_raw: ipar=%s, size=%d\n", ipar->full_name, intsize);

        if (ointsize != intsize)
                return -EINVAL;

        /* Look for this #address-cells. We have to implement the old linux
         * trick of looking for the parent here as some device-trees rely on it
         */
        old = of_node_get(ipar);
        do {
                tmp = of_get_property(old, "#address-cells", NULL);
                tnode = of_get_parent(old);
                of_node_put(old);
                old = tnode;
        } while(old && tmp == NULL);
        of_node_put(old);
        old = NULL;
        addrsize = (tmp == NULL) ? 2 : *tmp;

        DBG(" -> addrsize=%d\n", addrsize);

        /* Now start the actual "proper" walk of the interrupt tree */
        while (ipar != NULL) {
                /* Now check if cursor is an interrupt-controller and if it is
                 * then we are done
                 */
                if (of_get_property(ipar, "interrupt-controller", NULL) !=
                                NULL) {
                        DBG(" -> got it !\n");
                        memcpy(out_irq->specifier, intspec,
                               intsize * sizeof(u32));
                        out_irq->size = intsize;
                        out_irq->controller = ipar;
                        of_node_put(old);
                        return 0;
                }

                /* Now look for an interrupt-map */
                imap = of_get_property(ipar, "interrupt-map", &imaplen);
                /* No interrupt map, check for an interrupt parent */
                if (imap == NULL) {
                        DBG(" -> no map, getting parent\n");
                        newpar = of_irq_find_parent(ipar);
                        goto skiplevel;
                }
                imaplen /= sizeof(u32);

                /* Look for a mask */
                imask = of_get_property(ipar, "interrupt-map-mask", NULL);

                /* If we were passed no "reg" property and we attempt to parse
                 * an interrupt-map, then #address-cells must be 0.
                 * Fail if it's not.
                 */
                if (addr == NULL && addrsize != 0) {
                        DBG(" -> no reg passed in when needed !\n");
                        goto fail;
                }

                /* Parse interrupt-map */
                match = 0;
                while (imaplen > (addrsize + intsize + 1) && !match) {
                        /* Compare specifiers */
                        match = 1;
                        for (i = 0; i < addrsize && match; ++i) {
                                u32 mask = imask ? imask[i] : 0xffffffffu;
                                match = ((addr[i] ^ imap[i]) & mask) == 0;
                        }
                        for (; i < (addrsize + intsize) && match; ++i) {
                                u32 mask = imask ? imask[i] : 0xffffffffu;
                                match =
                                   ((intspec[i-addrsize] ^ imap[i]) & mask) == 0;
                        }
                        imap += addrsize + intsize;
                        imaplen -= addrsize + intsize;

                        DBG(" -> match=%d (imaplen=%d)\n", match, imaplen);

                        /* Get the interrupt parent */
                        if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
                                newpar = of_node_get(of_irq_dflt_pic);
                        else
                                newpar = of_find_node_by_phandle((phandle)*imap);
                        imap++;
                        --imaplen;

                        /* Check if not found */
                        if (newpar == NULL) {
                                DBG(" -> imap parent not found !\n");
                                goto fail;
                        }

                        /* Get #interrupt-cells and #address-cells of new
                         * parent
                         */
                        tmp = of_get_property(newpar, "#interrupt-cells", NULL);
                        if (tmp == NULL) {
                                DBG(" -> parent lacks #interrupt-cells !\n");
                                goto fail;
                        }
                        newintsize = *tmp;
                        tmp = of_get_property(newpar, "#address-cells", NULL);
                        newaddrsize = (tmp == NULL) ? 0 : *tmp;

                        DBG(" -> newintsize=%d, newaddrsize=%d\n",
                            newintsize, newaddrsize);

                        /* Check for malformed properties */
                        if (imaplen < (newaddrsize + newintsize))
                                goto fail;

                        imap += newaddrsize + newintsize;
                        imaplen -= newaddrsize + newintsize;

                        DBG(" -> imaplen=%d\n", imaplen);
                }
                if (!match)
                        goto fail;

                of_node_put(old);
                old = of_node_get(newpar);
                addrsize = newaddrsize;
                intsize = newintsize;
                intspec = imap - intsize;
                addr = intspec - addrsize;

        skiplevel:
                /* Iterate again with new parent */
                DBG(" -> new parent: %s\n", newpar ? newpar->full_name : "<>");
                of_node_put(ipar);
                ipar = newpar;
                newpar = NULL;
        }
 fail:
        of_node_put(ipar);
        of_node_put(old);
        of_node_put(newpar);

        return -EINVAL;
}
EXPORT_SYMBOL_GPL(of_irq_map_raw);

#if defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)
static int of_irq_map_oldworld(struct device_node *device, int index,
                               struct of_irq *out_irq)
{
        const u32 *ints = NULL;
        int intlen;

        /*
         * Old machines just have a list of interrupt numbers
         * and no interrupt-controller nodes. We also have dodgy
         * cases where the APPL,interrupts property is completely
         * missing behind pci-pci bridges and we have to get it
         * from the parent (the bridge itself, as apple just wired
         * everything together on these)
         */
        while (device) {
                ints = of_get_property(device, "AAPL,interrupts", &intlen);
                if (ints != NULL)
                        break;
                device = device->parent;
                if (device && strcmp(device->type, "pci") != 0)
                        break;
        }
        if (ints == NULL)
                return -EINVAL;
        intlen /= sizeof(u32);

        if (index >= intlen)
                return -EINVAL;

        out_irq->controller = NULL;
        out_irq->specifier[0] = ints[index];
        out_irq->size = 1;

        return 0;
}
#else /* defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32) */
static int of_irq_map_oldworld(struct device_node *device, int index,
                               struct of_irq *out_irq)
{
        return -EINVAL;
}
#endif /* !(defined(CONFIG_PPC_PMAC) && defined(CONFIG_PPC32)) */

int of_irq_map_one(struct device_node *device, int index, struct of_irq *out_irq)
{
        struct device_node *p;
        const u32 *intspec, *tmp, *addr;
        u32 intsize, intlen;
        int res = -EINVAL;

        DBG("of_irq_map_one: dev=%s, index=%d\n", device->full_name, index);

        /* OldWorld mac stuff is "special", handle out of line */
        if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
                return of_irq_map_oldworld(device, index, out_irq);

        /* Get the interrupts property */
        intspec = of_get_property(device, "interrupts", &intlen);
        if (intspec == NULL)
                return -EINVAL;
        intlen /= sizeof(u32);

        /* Get the reg property (if any) */
        addr = of_get_property(device, "reg", NULL);

        /* Look for the interrupt parent. */
        p = of_irq_find_parent(device);
        if (p == NULL)
                return -EINVAL;

        /* Get size of interrupt specifier */
        tmp = of_get_property(p, "#interrupt-cells", NULL);
        if (tmp == NULL)
                goto out;
        intsize = *tmp;

        DBG(" intsize=%d intlen=%d\n", intsize, intlen);

        /* Check index */
        if ((index + 1) * intsize > intlen)
                goto out;

        /* Get new specifier and map it */
        res = of_irq_map_raw(p, intspec + index * intsize, intsize,
                             addr, out_irq);
out:
        of_node_put(p);
        return res;
}
EXPORT_SYMBOL_GPL(of_irq_map_one);

/**
 * Search the device tree for the best MAC address to use.  'mac-address' is
 * checked first, because that is supposed to contain to "most recent" MAC
 * address. If that isn't set, then 'local-mac-address' is checked next,
 * because that is the default address.  If that isn't set, then the obsolete
 * 'address' is checked, just in case we're using an old device tree.
 *
 * Note that the 'address' property is supposed to contain a virtual address of
 * the register set, but some DTS files have redefined that property to be the
 * MAC address.
 *
 * All-zero MAC addresses are rejected, because those could be properties that
 * exist in the device tree, but were not set by U-Boot.  For example, the
 * DTS could define 'mac-address' and 'local-mac-address', with zero MAC
 * addresses.  Some older U-Boots only initialized 'local-mac-address'.  In
 * this case, the real MAC is in 'local-mac-address', and 'mac-address' exists
 * but is all zeros.
*/
const void *of_get_mac_address(struct device_node *np)
{
        struct property *pp;

        pp = of_find_property(np, "mac-address", NULL);
        if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
                return pp->value;

        pp = of_find_property(np, "local-mac-address", NULL);
        if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
                return pp->value;

        pp = of_find_property(np, "address", NULL);
        if (pp && (pp->length == 6) && is_valid_ether_addr(pp->value))
                return pp->value;

        return NULL;
}
EXPORT_SYMBOL(of_get_mac_address);

int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
{
        int irq = irq_of_parse_and_map(dev, index);

        /* Only dereference the resource if both the
         * resource and the irq are valid. */
        if (r && irq != NO_IRQ) {
                r->start = r->end = irq;
                r->flags = IORESOURCE_IRQ;
        }

        return irq;
}
EXPORT_SYMBOL_GPL(of_irq_to_resource);

void __iomem *of_iomap(struct device_node *np, int index)
{
        struct resource res;

        if (of_address_to_resource(np, index, &res))
                return NULL;

        return ioremap(res.start, 1 + res.end - res.start);
}
EXPORT_SYMBOL(of_iomap);