[SPARC]: Beginnings of generic of_device framework.

The idea is to fully construct the device register and
interrupt values into these of_device objects, and convert
all of SBUS, EBUS, ISA drivers to use this new stuff.

Much ideas and code taken from Ben H.'s powerpc work.

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 908 insertions, 4 deletions

diff --git a/arch/sparc/kernel/of_device.c b/arch/sparc/kernel/of_device.c
index 80a809478781..13a70bd87817 100644
--- a/arch/sparc/kernel/of_device.c
+++ b/arch/sparc/kernel/of_device.c
@@ -153,10 +153,424 @@ struct bus_type sbus_bus_type = {
 EXPORT_SYMBOL(sbus_bus_type);
 #endif
 
+struct bus_type of_bus_type = {
+       .name    = "of",
+       .match   = of_platform_bus_match,
+       .probe   = of_device_probe,
+       .remove  = of_device_remove,
+       .suspend = of_device_suspend,
+       .resume  = of_device_resume,
+};
+EXPORT_SYMBOL(of_bus_type);
+
+static inline u64 of_read_addr(u32 *cell, int size)
+{
+        u64 r = 0;
+        while (size--)
+                r = (r << 32) | *(cell++);
+        return r;
+}
+
+static void __init get_cells(struct device_node *dp,
+                             int *addrc, int *sizec)
+{
+        if (addrc)
+                *addrc = of_n_addr_cells(dp);
+        if (sizec)
+                *sizec = of_n_size_cells(dp);
+}
+
+/* Max address size we deal with */
+#define OF_MAX_ADDR_CELLS       4
+
+struct of_bus {
+        const char      *name;
+        const char      *addr_prop_name;
+        int             (*match)(struct device_node *parent);
+        void            (*count_cells)(struct device_node *child,
+                                       int *addrc, int *sizec);
+        u64             (*map)(u32 *addr, u32 *range, int na, int ns, int pna);
+        int             (*translate)(u32 *addr, u64 offset, int na);
+        unsigned int    (*get_flags)(u32 *addr);
+};
+
+/*
+ * Default translator (generic bus)
+ */
+
+static void of_bus_default_count_cells(struct device_node *dev,
+                                       int *addrc, int *sizec)
+{
+        get_cells(dev, addrc, sizec);
+}
+
+static u64 of_bus_default_map(u32 *addr, u32 *range, int na, int ns, int pna)
+{
+        u64 cp, s, da;
+
+        cp = of_read_addr(range, na);
+        s  = of_read_addr(range + na + pna, ns);
+        da = of_read_addr(addr, na);
+
+        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_addr(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(u32 *addr)
+{
+        return IORESOURCE_MEM;
+}
+
+
+/*
+ * PCI bus specific translator
+ */
+
+static int of_bus_pci_match(struct device_node *np)
+{
+        return !strcmp(np->type, "pci") || !strcmp(np->type, "pciex");
+}
+
+static void of_bus_pci_count_cells(struct device_node *np,
+                                   int *addrc, int *sizec)
+{
+        if (addrc)
+                *addrc = 3;
+        if (sizec)
+                *sizec = 2;
+}
+
+static u64 of_bus_pci_map(u32 *addr, u32 *range, int na, int ns, int pna)
+{
+        u64 cp, s, da;
+
+        /* Check address type match */
+        if ((addr[0] ^ range[0]) & 0x03000000)
+                return OF_BAD_ADDR;
+
+        /* Read address values, skipping high cell */
+        cp = of_read_addr(range + 1, na - 1);
+        s  = of_read_addr(range + na + pna, ns);
+        da = of_read_addr(addr + 1, na - 1);
+
+        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);
+}
+
+static unsigned int of_bus_pci_get_flags(u32 *addr)
+{
+        unsigned int flags = 0;
+        u32 w = addr[0];
+
+        switch((w >> 24) & 0x03) {
+        case 0x01:
+                flags |= IORESOURCE_IO;
+        case 0x02: /* 32 bits */
+        case 0x03: /* 64 bits */
+                flags |= IORESOURCE_MEM;
+        }
+        if (w & 0x40000000)
+                flags |= IORESOURCE_PREFETCH;
+        return flags;
+}
+
+/*
+ * SBUS bus specific translator
+ */
+
+static int of_bus_sbus_match(struct device_node *np)
+{
+        return !strcmp(np->name, "sbus") ||
+                !strcmp(np->name, "sbi");
+}
+
+static void of_bus_sbus_count_cells(struct device_node *child,
+                                   int *addrc, int *sizec)
+{
+        if (addrc)
+                *addrc = 2;
+        if (sizec)
+                *sizec = 1;
+}
+
+static u64 of_bus_sbus_map(u32 *addr, u32 *range, int na, int ns, int pna)
+{
+        return of_bus_default_map(addr, range, na, ns, pna);
+}
+
+static int of_bus_sbus_translate(u32 *addr, u64 offset, int na)
+{
+        return of_bus_default_translate(addr, offset, na);
+}
+
+static unsigned int of_bus_sbus_get_flags(u32 *addr)
+{
+        return IORESOURCE_MEM;
+}
+
+
+/*
+ * Array of bus specific translators
+ */
+
+static struct of_bus of_busses[] = {
+        /* PCI */
+        {
+                .name = "pci",
+                .addr_prop_name = "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,
+        },
+        /* SBUS */
+        {
+                .name = "sbus",
+                .addr_prop_name = "reg",
+                .match = of_bus_sbus_match,
+                .count_cells = of_bus_sbus_count_cells,
+                .map = of_bus_sbus_map,
+                .translate = of_bus_sbus_translate,
+                .get_flags = of_bus_sbus_get_flags,
+        },
+        /* Default */
+        {
+                .name = "default",
+                .addr_prop_name = "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 __init build_one_resource(struct device_node *parent,
+                                     struct of_bus *bus,
+                                     struct of_bus *pbus,
+                                     u32 *addr,
+                                     int na, int ns, int pna)
+{
+        u32 *ranges;
+        unsigned int rlen;
+        int rone;
+        u64 offset = OF_BAD_ADDR;
+
+        ranges = of_get_property(parent, "ranges", &rlen);
+        if (ranges == NULL || rlen == 0) {
+                offset = of_read_addr(addr, na);
+                memset(addr, 0, pna * 4);
+                goto finish;
+        }
+
+        /* 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)
+                return 1;
+
+        memcpy(addr, ranges + na, 4 * pna);
+
+finish:
+        /* Translate it into parent bus space */
+        return pbus->translate(addr, offset, pna);
+}
+
+static void __init build_device_resources(struct of_device *op,
+                                          struct device *parent)
+{
+        struct of_device *p_op;
+        struct of_bus *bus;
+        int na, ns;
+        int index, num_reg;
+        void *preg;
+
+        if (!parent)
+                return;
+
+        p_op = to_of_device(parent);
+        bus = of_match_bus(p_op->node);
+        bus->count_cells(op->node, &na, &ns);
+
+        preg = of_get_property(op->node, bus->addr_prop_name, &num_reg);
+        if (!preg || num_reg == 0)
+                return;
+
+        /* Convert to num-cells.  */
+        num_reg /= 4;
+
+        /* Conver to num-entries.  */
+        num_reg /= na + ns;
+
+        for (index = 0; index < num_reg; index++) {
+                struct resource *r = &op->resource[index];
+                u32 addr[OF_MAX_ADDR_CELLS];
+                u32 *reg = (preg + (index * ((na + ns) * 4)));
+                struct device_node *dp = op->node;
+                struct device_node *pp = p_op->node;
+                struct of_bus *pbus;
+                u64 size, result = OF_BAD_ADDR;
+                unsigned long flags;
+                int dna, dns;
+                int pna, pns;
+
+                size = of_read_addr(reg + na, ns);
+                flags = bus->get_flags(reg);
+
+                memcpy(addr, reg, na * 4);
+
+                /* If the immediate parent has no ranges property to apply,
+                 * just use a 1<->1 mapping.
+                 */
+                if (of_find_property(pp, "ranges", NULL) == NULL) {
+                        result = of_read_addr(addr, na);
+                        goto build_res;
+                }
+
+                dna = na;
+                dns = ns;
+
+                while (1) {
+                        dp = pp;
+                        pp = dp->parent;
+                        if (!pp) {
+                                result = of_read_addr(addr, dna);
+                                break;
+                        }
+
+                        pbus = of_match_bus(pp);
+                        pbus->count_cells(dp, &pna, &pns);
+
+                        if (build_one_resource(dp, bus, pbus, addr, dna, dns, pna))
+                                break;
+
+                        dna = pna;
+                        dns = pns;
+                        bus = pbus;
+                }
+
+        build_res:
+                memset(r, 0, sizeof(*r));
+                if (result != OF_BAD_ADDR) {
+                        r->start = result;
+                        r->end = result + size - 1;
+                        r->flags = flags;
+                } else {
+                        r->start = ~0UL;
+                        r->end = ~0UL;
+                }
+                r->name = op->node->name;
+        }
+}
+
+static struct of_device * __init scan_one_device(struct device_node *dp,
+                                                 struct device *parent)
+{
+        struct of_device *op = kzalloc(sizeof(*op), GFP_KERNEL);
+        unsigned int *irq;
+        int len;
+
+        if (!op)
+                return NULL;
+
+        op->node = dp;
+
+        op->clock_freq = of_getintprop_default(dp, "clock-frequency",
+                                               (25*1000*1000));
+        op->portid = of_getintprop_default(dp, "upa-portid", -1);
+        if (op->portid == -1)
+                op->portid = of_getintprop_default(dp, "portid", -1);
+
+        irq = of_get_property(dp, "interrupts", &len);
+        if (irq)
+                op->irq = *irq;
+        else
+                op->irq = 0xffffffff;
+
+        build_device_resources(op, parent);
+
+        op->dev.parent = parent;
+        op->dev.bus = &of_bus_type;
+        if (!parent)
+                strcpy(op->dev.bus_id, "root");
+        else
+                strcpy(op->dev.bus_id, dp->path_component_name);
+
+        if (of_device_register(op)) {
+                printk("%s: Could not register of device.\n",
+                       dp->full_name);
+                kfree(op);
+                op = NULL;
+        }
+
+        return op;
+}
+
+static void __init scan_tree(struct device_node *dp, struct device *parent)
+{
+        while (dp) {
+                struct of_device *op = scan_one_device(dp, parent);
+
+                if (op)
+                        scan_tree(dp->child, &op->dev);
+
+                dp = dp->sibling;
+        }
+}
+
+static void __init scan_of_devices(void)
+{
+        struct device_node *root = of_find_node_by_path("/");
+        struct of_device *parent;
+
+        parent = scan_one_device(root, NULL);
+        if (!parent)
+                return;
+
+        scan_tree(root->child, &parent->dev);
+}
+
 static int __init of_bus_driver_init(void)
 {
-        int err = 0;
+        int err;
 
+        err = bus_register(&of_bus_type);
 #ifdef CONFIG_PCI
         if (!err)
                 err = bus_register(&ebus_bus_type);
@@ -165,7 +579,11 @@ static int __init of_bus_driver_init(void)
         if (!err)
                 err = bus_register(&sbus_bus_type);
 #endif
-        return 0;
+
+        if (!err)
+                scan_of_devices();
+
+        return err;
 }
 
 postcore_initcall(of_bus_driver_init);
diff --git a/arch/sparc64/kernel/of_device.c b/arch/sparc64/kernel/of_device.c
index 768475bbce82..00502dc280ef 100644
--- a/arch/sparc64/kernel/of_device.c
+++ b/arch/sparc64/kernel/of_device.c
@@ -163,10 +163,492 @@ struct bus_type sbus_bus_type = {
 EXPORT_SYMBOL(sbus_bus_type);
 #endif
 
+struct bus_type of_bus_type = {
+       .name    = "of",
+       .match   = of_platform_bus_match,
+       .probe   = of_device_probe,
+       .remove  = of_device_remove,
+       .suspend = of_device_suspend,
+       .resume  = of_device_resume,
+};
+EXPORT_SYMBOL(of_bus_type);
+
+static inline u64 of_read_addr(u32 *cell, int size)
+{
+        u64 r = 0;
+        while (size--)
+                r = (r << 32) | *(cell++);
+        return r;
+}
+
+static void __init get_cells(struct device_node *dp,
+                             int *addrc, int *sizec)
+{
+        if (addrc)
+                *addrc = of_n_addr_cells(dp);
+        if (sizec)
+                *sizec = of_n_size_cells(dp);
+}
+
+/* Max address size we deal with */
+#define OF_MAX_ADDR_CELLS       4
+
+struct of_bus {
+        const char      *name;
+        const char      *addr_prop_name;
+        int             (*match)(struct device_node *parent);
+        void            (*count_cells)(struct device_node *child,
+                                       int *addrc, int *sizec);
+        u64             (*map)(u32 *addr, u32 *range, int na, int ns, int pna);
+        int             (*translate)(u32 *addr, u64 offset, int na);
+        unsigned int    (*get_flags)(u32 *addr);
+};
+
+/*
+ * Default translator (generic bus)
+ */
+
+static void of_bus_default_count_cells(struct device_node *dev,
+                                       int *addrc, int *sizec)
+{
+        get_cells(dev, addrc, sizec);
+}
+
+static u64 of_bus_default_map(u32 *addr, u32 *range, int na, int ns, int pna)
+{
+        u64 cp, s, da;
+
+        cp = of_read_addr(range, na);
+        s  = of_read_addr(range + na + pna, ns);
+        da = of_read_addr(addr, na);
+
+        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_addr(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(u32 *addr)
+{
+        return IORESOURCE_MEM;
+}
+
+
+/*
+ * PCI bus specific translator
+ */
+
+static int of_bus_pci_match(struct device_node *np)
+{
+        return !strcmp(np->type, "pci") || !strcmp(np->type, "pciex");
+}
+
+static void of_bus_pci_count_cells(struct device_node *np,
+                                   int *addrc, int *sizec)
+{
+        if (addrc)
+                *addrc = 3;
+        if (sizec)
+                *sizec = 2;
+}
+
+static u64 of_bus_pci_map(u32 *addr, u32 *range, int na, int ns, int pna)
+{
+        u64 cp, s, da;
+
+        /* Check address type match */
+        if ((addr[0] ^ range[0]) & 0x03000000)
+                return OF_BAD_ADDR;
+
+        /* Read address values, skipping high cell */
+        cp = of_read_addr(range + 1, na - 1);
+        s  = of_read_addr(range + na + pna, ns);
+        da = of_read_addr(addr + 1, na - 1);
+
+        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);
+}
+
+static unsigned int of_bus_pci_get_flags(u32 *addr)
+{
+        unsigned int flags = 0;
+        u32 w = addr[0];
+
+        switch((w >> 24) & 0x03) {
+        case 0x01:
+                flags |= IORESOURCE_IO;
+        case 0x02: /* 32 bits */
+        case 0x03: /* 64 bits */
+                flags |= IORESOURCE_MEM;
+        }
+        if (w & 0x40000000)
+                flags |= IORESOURCE_PREFETCH;
+        return flags;
+}
+
+/*
+ * 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, 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_addr(range + 1, na - 1);
+        s  = of_read_addr(range + na + pna, ns);
+        da = of_read_addr(addr + 1, na - 1);
+
+        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(u32 *addr)
+{
+        unsigned int flags = 0;
+        u32 w = addr[0];
+
+        if (w & 1)
+                flags |= IORESOURCE_IO;
+        else
+                flags |= IORESOURCE_MEM;
+        return flags;
+}
+
+/*
+ * SBUS bus specific translator
+ */
+
+static int of_bus_sbus_match(struct device_node *np)
+{
+        return !strcmp(np->name, "sbus") ||
+                !strcmp(np->name, "sbi");
+}
+
+static void of_bus_sbus_count_cells(struct device_node *child,
+                                   int *addrc, int *sizec)
+{
+        if (addrc)
+                *addrc = 2;
+        if (sizec)
+                *sizec = 1;
+}
+
+static u64 of_bus_sbus_map(u32 *addr, u32 *range, int na, int ns, int pna)
+{
+        return of_bus_default_map(addr, range, na, ns, pna);
+}
+
+static int of_bus_sbus_translate(u32 *addr, u64 offset, int na)
+{
+        return of_bus_default_translate(addr, offset, na);
+}
+
+static unsigned int of_bus_sbus_get_flags(u32 *addr)
+{
+        return IORESOURCE_MEM;
+}
+
+
+/*
+ * Array of bus specific translators
+ */
+
+static struct of_bus of_busses[] = {
+        /* PCI */
+        {
+                .name = "pci",
+                .addr_prop_name = "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,
+        },
+        /* ISA */
+        {
+                .name = "isa",
+                .addr_prop_name = "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,
+        },
+        /* SBUS */
+        {
+                .name = "sbus",
+                .addr_prop_name = "reg",
+                .match = of_bus_sbus_match,
+                .count_cells = of_bus_sbus_count_cells,
+                .map = of_bus_sbus_map,
+                .translate = of_bus_sbus_translate,
+                .get_flags = of_bus_sbus_get_flags,
+        },
+        /* Default */
+        {
+                .name = "default",
+                .addr_prop_name = "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 __init build_one_resource(struct device_node *parent,
+                                     struct of_bus *bus,
+                                     struct of_bus *pbus,
+                                     u32 *addr,
+                                     int na, int ns, int pna)
+{
+        u32 *ranges;
+        unsigned int rlen;
+        int rone;
+        u64 offset = OF_BAD_ADDR;
+
+        ranges = of_get_property(parent, "ranges", &rlen);
+        if (ranges == NULL || rlen == 0) {
+                offset = of_read_addr(addr, na);
+                memset(addr, 0, pna * 4);
+                goto finish;
+        }
+
+        /* 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)
+                return 1;
+
+        memcpy(addr, ranges + na, 4 * pna);
+
+finish:
+        /* Translate it into parent bus space */
+        return pbus->translate(addr, offset, pna);
+}
+
+static void __init build_device_resources(struct of_device *op,
+                                          struct device *parent)
+{
+        struct of_device *p_op;
+        struct of_bus *bus;
+        int na, ns;
+        int index, num_reg;
+        void *preg;
+
+        if (!parent)
+                return;
+
+        p_op = to_of_device(parent);
+        bus = of_match_bus(p_op->node);
+        bus->count_cells(op->node, &na, &ns);
+
+        preg = of_get_property(op->node, bus->addr_prop_name, &num_reg);
+        if (!preg || num_reg == 0)
+                return;
+
+        /* Convert to num-cells.  */
+        num_reg /= 4;
+
+        /* Conver to num-entries.  */
+        num_reg /= na + ns;
+
+        for (index = 0; index < num_reg; index++) {
+                struct resource *r = &op->resource[index];
+                u32 addr[OF_MAX_ADDR_CELLS];
+                u32 *reg = (preg + (index * ((na + ns) * 4)));
+                struct device_node *dp = op->node;
+                struct device_node *pp = p_op->node;
+                struct of_bus *pbus;
+                u64 size, result = OF_BAD_ADDR;
+                unsigned long flags;
+                int dna, dns;
+                int pna, pns;
+
+                size = of_read_addr(reg + na, ns);
+                flags = bus->get_flags(reg);
+
+                memcpy(addr, reg, na * 4);
+
+                /* If the immediate parent has no ranges property to apply,
+                 * just use a 1<->1 mapping.  Unless it is the 'dma' child
+                 * of an isa bus, which must be passed up towards the root.
+                 *
+                 * Also, don't try to translate PMU bus device registers.
+                 */
+                if ((of_find_property(pp, "ranges", NULL) == NULL &&
+                     strcmp(pp->name, "dma") != 0) ||
+                    !strcmp(pp->name, "pmu")) {
+                        result = of_read_addr(addr, na);
+                        goto build_res;
+                }
+
+                dna = na;
+                dns = ns;
+
+                while (1) {
+                        dp = pp;
+                        pp = dp->parent;
+                        if (!pp) {
+                                result = of_read_addr(addr, dna);
+                                break;
+                        }
+
+                        pbus = of_match_bus(pp);
+                        pbus->count_cells(dp, &pna, &pns);
+
+                        if (build_one_resource(dp, bus, pbus, addr, dna, dns, pna))
+                                break;
+
+                        dna = pna;
+                        dns = pns;
+                        bus = pbus;
+                }
+
+        build_res:
+                memset(r, 0, sizeof(*r));
+                if (result != OF_BAD_ADDR) {
+                        r->start = result;
+                        r->end = result + size - 1;
+                        r->flags = flags;
+                } else {
+                        r->start = ~0UL;
+                        r->end = ~0UL;
+                }
+                r->name = op->node->name;
+        }
+}
+
+static struct of_device * __init scan_one_device(struct device_node *dp,
+                                                 struct device *parent)
+{
+        struct of_device *op = kzalloc(sizeof(*op), GFP_KERNEL);
+        unsigned int *irq;
+        int len;
+
+        if (!op)
+                return NULL;
+
+        op->node = dp;
+
+        op->clock_freq = of_getintprop_default(dp, "clock-frequency",
+                                               (25*1000*1000));
+        op->portid = of_getintprop_default(dp, "upa-portid", -1);
+        if (op->portid == -1)
+                op->portid = of_getintprop_default(dp, "portid", -1);
+
+        irq = of_get_property(dp, "interrupts", &len);
+        if (irq)
+                op->irq = *irq;
+        else
+                op->irq = 0xffffffff;
+
+        build_device_resources(op, parent);
+
+        op->dev.parent = parent;
+        op->dev.bus = &of_bus_type;
+        if (!parent)
+                strcpy(op->dev.bus_id, "root");
+        else
+                strcpy(op->dev.bus_id, dp->path_component_name);
+
+        if (of_device_register(op)) {
+                printk("%s: Could not register of device.\n",
+                       dp->full_name);
+                kfree(op);
+                op = NULL;
+        }
+
+        return op;
+}
+
+static void __init scan_tree(struct device_node *dp, struct device *parent)
+{
+        while (dp) {
+                struct of_device *op = scan_one_device(dp, parent);
+
+                if (op)
+                        scan_tree(dp->child, &op->dev);
+
+                dp = dp->sibling;
+        }
+}
+
+static void __init scan_of_devices(void)
+{
+        struct device_node *root = of_find_node_by_path("/");
+        struct of_device *parent;
+
+        parent = scan_one_device(root, NULL);
+        if (!parent)
+                return;
+
+        scan_tree(root->child, &parent->dev);
+}
+
 static int __init of_bus_driver_init(void)
 {
-        int err = 0;
+        int err;
 
+        err = bus_register(&of_bus_type);
 #ifdef CONFIG_PCI
         if (!err)
                 err = bus_register(&isa_bus_type);
@@ -177,7 +659,11 @@ static int __init of_bus_driver_init(void)
         if (!err)
                 err = bus_register(&sbus_bus_type);
 #endif
-        return 0;
+
+        if (!err)
+                scan_of_devices();
+
+        return err;
 }
 
 postcore_initcall(of_bus_driver_init);