Please bear with me - another rename checkin. This qualifies as trivial, no
[coreboot.git] / src / devices / device.c
index 9e5e24580c4de16192f210dd745acc8634601070..635f876bbebb940ee2f011241240535078e5cf3d 100644 (file)
@@ -1,6 +1,21 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * It was originally based on the Linux kernel (arch/i386/kernel/pci-pc.c).
+ *
+ * Modifications are:
+ * Copyright (C) 2003 Eric Biederman <ebiederm@xmission.com>
+ * Copyright (C) 2003-2004 Linux Networx
+ * (Written by Eric Biederman <ebiederman@lnxi.com> for Linux Networx)
+ * Copyright (C) 2003 Ronald G. Minnich <rminnich@gmail.com>
+ * Copyright (C) 2004-2005 Li-Ta Lo <ollie@lanl.gov>
+ * Copyright (C) 2005-2006 Tyan
+ * (Written by Yinghai Lu <yhlu@tyan.com> for Tyan)
+ * Copyright (C) 2005-2006 Stefan Reinauer <stepan@openbios.org>
+ */
+
 /*
  *      (c) 1999--2000 Martin Mares <mj@suse.cz>
- *      (c) 2003 Eric Biederman <ebiederm@xmission.com>
  */
 /* lots of mods by ron minnich (rminnich@lanl.gov), with 
  * the final architecture guidance from Tom Merritt (tjm@codegen.com)
 #include <arch/io.h>
 #include <device/device.h>
 #include <device/pci.h>
+#include <device/pci_ids.h>
+#include <stdlib.h>
+#include <string.h>
+#include <smp/spinlock.h>
+
+/** Linked list of ALL devices */
+struct device *all_devices = &dev_root;
+/** Pointer to the last device */
+extern struct device **last_dev_p;
+
+/** The upper limit of MEM resource of the devices.
+ * Reserve 20M for the system */
+#define DEVICE_MEM_HIGH 0xFEBFFFFFUL
+/** The lower limit of IO resource of the devices.
+ * Reserve 4k for ISA/Legacy devices */
+#define DEVICE_IO_START 0x1000
 
 /**
- * This is the root of the device tree. A PCI tree always has 
- * one bus, bus 0. Bus 0 contains devices and bridges. 
+ * @brief Allocate a new device structure.
+ * 
+ * Allocte a new device structure and attached it to the device tree as a
+ * child of the parent bus.
+ *
+ * @param parent parent bus the newly created device attached to.
+ * @param path path to the device to be created.
+ *
+ * @return pointer to the newly created device structure.
+ *
+ * @see device_path
  */
-struct device dev_root;
-/* Linked list of ALL devices */
-struct device *all_devices = 0;
-/* pointer to the last device */
-static struct device **last_dev_p = &all_devices;
+static spinlock_t dev_lock = SPIN_LOCK_UNLOCKED;
+device_t alloc_dev(struct bus *parent, struct device_path *path)
+{
+       device_t dev, child;
+       int link;
 
-#define DEVICE_MEM_HIGH  0xFEC00000UL /* Reserve 20M for the system */
-#define DEVICE_IO_START 0x1000
+       spin_lock(&dev_lock);   
 
+       /* Find the last child of our parent */
+       for(child = parent->children; child && child->sibling; ) {
+               child = child->sibling;
+       }
 
-/* Append a new device to the global device chain.
- * The chain is used to find devices once everything is set up.
- */
-void append_device(struct device *dev)
-{
+       dev = malloc(sizeof(*dev));
+       if (dev == 0) {
+               die("DEV: out of memory.\n");
+       }
+       memset(dev, 0, sizeof(*dev));
+       memcpy(&dev->path, path, sizeof(*path));
+
+       /* Initialize the back pointers in the link fields */
+       for(link = 0; link < MAX_LINKS; link++) {
+               dev->link[link].dev  = dev;
+               dev->link[link].link = link;
+       }
+
+       /* By default devices are enabled */
+       dev->enabled = 1;
+
+       /* Add the new device to the list of children of the bus. */
+       dev->bus = parent;
+       if (child) {
+               child->sibling = dev;
+       } else {
+               parent->children = dev;
+       }
+
+       /* Append a new device to the global device list.
+        * The list is used to find devices once everything is set up.
+        */
        *last_dev_p = dev;
        last_dev_p = &dev->next;
-}
 
+       spin_unlock(&dev_lock);
+       return dev;
+}
 
-/** round a number to an alignment. 
+/**
+ * @brief round a number up to an alignment. 
  * @param val the starting value
  * @param roundup Alignment as a power of two
  * @returns rounded up number
  */
-static unsigned long round(unsigned long val, unsigned long roundup)
-{
-       /* ROUNDUP MUST BE A POWER OF TWO. */
-       unsigned long inverse;
-       inverse = ~(roundup - 1);
-       val += (roundup - 1);
-       val &= inverse;
-       return val;
-}
-
-static unsigned long round_down(unsigned long val, unsigned long round_down)
+static resource_t round(resource_t val, unsigned long pow)
 {
-       /* ROUND_DOWN MUST BE A POWER OF TWO. */
-       unsigned long inverse;
-       inverse = ~(round_down - 1);
-       val &= inverse;
+       resource_t mask;
+       mask = (1ULL << pow) - 1ULL;
+       val += mask;
+       val &= ~mask;
        return val;
 }
 
-
 /** Read the resources on all devices of a given bus.
  * @param bus bus to read the resources on.
  */
-static void read_resources(struct device *bus)
+static void read_resources(struct bus *bus)
 {
        struct device *curdev;
 
-       
+       printk_spew("%s read_resources bus %d link: %d\n",
+               dev_path(bus->dev), bus->secondary, bus->link);
+
        /* Walk through all of the devices and find which resources they need. */
        for(curdev = bus->children; curdev; curdev = curdev->sibling) {
-               if (curdev->resources > 0) {
+               unsigned links;
+               int i;
+               if (curdev->have_resources) {
+                       continue;
+               }
+               if (!curdev->enabled) {
+                       continue;
+               }
+               if (!curdev->ops || !curdev->ops->read_resources) {
+                       printk_err("%s missing read_resources\n",
+                               dev_path(curdev));
                        continue;
                }
                curdev->ops->read_resources(curdev);
-       }
-}
-
-static struct device *largest_resource(struct device *bus, struct resource **result_res,
-       unsigned long type_mask, unsigned long type)
-{
-       struct device *curdev;
-       struct device *result_dev = 0;
-       struct resource *last = *result_res;
-       struct resource *result = 0;
-       int seen_last = 0;
-       for(curdev = bus->children; curdev; curdev = curdev->sibling) {
-               int i;
+               curdev->have_resources = 1;
+               /* Read in subtractive resources behind the current device */
+               links = 0;
                for(i = 0; i < curdev->resources; i++) {
-                       struct resource *resource = &curdev->resource[i];
-                       /* If it isn't the right kind of resource ignore it */
-                       if ((resource->flags & type_mask) != type) {
+                       struct resource *resource;
+                       unsigned link;
+                       resource = &curdev->resource[i];
+                       if (!(resource->flags & IORESOURCE_SUBTRACTIVE)) 
                                continue;
-                       }
-                       /* Be certain to pick the successor to last */
-                       if (resource == last) {
-                               seen_last = 1;
-                               continue;
-                       }
-                       if (last && (
-                               (last->align < resource->align) ||
-                               ((last->align == resource->align) &&
-                                       (last->size < resource->size)) ||
-                               ((last->align == resource->align) &&
-                                       (last->size == resource->size) &&
-                                       (!seen_last)))) {
+                       link = IOINDEX_SUBTRACTIVE_LINK(resource->index);
+                       if (link > MAX_LINKS) {
+                               printk_err("%s subtractive index on link: %d\n",
+                                       dev_path(curdev), link);
                                continue;
                        }
-                       if (!result || 
-                               (result->align < resource->align) ||
-                               ((result->align == resource->align) &&
-                                       (result->size < resource->size))) {
-                               result_dev = curdev;
-                               result = resource;
+                       if (!(links & (1 << link))) {
+                               links |= (1 << link);
+                               read_resources(&curdev->link[link]);
                        }
                }
        }
-       *result_res = result;
-       return result_dev;
+       printk_spew("%s read_resources bus %d link: %d done\n",
+               dev_path(bus->dev), bus->secondary, bus->link);
+}
+
+struct pick_largest_state {
+       struct resource *last;
+       struct device   *result_dev;
+       struct resource *result;
+       int seen_last;
+};
+
+static void pick_largest_resource(void *gp,
+       struct device *dev, struct resource *resource)
+{
+       struct pick_largest_state *state = gp;
+       struct resource *last;
+       last = state->last;
+       /* Be certain to pick the successor to last */
+       if (resource == last) {
+               state->seen_last = 1;
+               return;
+       }
+       if (resource->flags & IORESOURCE_FIXED ) return; //skip it 
+       if (last && (
+                   (last->align < resource->align) ||
+                   ((last->align == resource->align) &&
+                           (last->size < resource->size)) ||
+                   ((last->align == resource->align) &&
+                           (last->size == resource->size) &&
+                           (!state->seen_last)))) {
+               return;
+       }
+       if (!state->result || 
+               (state->result->align < resource->align) ||
+               ((state->result->align == resource->align) &&
+                       (state->result->size < resource->size)))
+       {
+               state->result_dev = dev;
+               state->result = resource;
+       }    
+}
+
+static struct device *largest_resource(struct bus *bus, struct resource **result_res,
+       unsigned long type_mask, unsigned long type)
+{
+       struct pick_largest_state state;
+
+       state.last = *result_res;
+       state.result_dev = 0;
+       state.result = 0;
+       state.seen_last = 0;
+
+       search_bus_resources(bus, type_mask, type, pick_largest_resource, &state);
+
+       *result_res = state.result;
+       return state.result_dev;
 }
 
 /* Compute allocate resources is the guts of the resource allocator.
@@ -158,18 +260,24 @@ static struct device *largest_resource(struct device *bus, struct resource **res
  */
 
 void compute_allocate_resource(
-       struct device *bus,
+       struct bus *bus,
        struct resource *bridge,
        unsigned long type_mask,
        unsigned long type)
 {
        struct device *dev;
        struct resource *resource;
-       unsigned long base;
+       resource_t base;
        unsigned long align, min_align;
        min_align = 0;
        base = bridge->base;
 
+       printk_spew("%s compute_allocate_%s: base: %08Lx size: %08Lx align: %d gran: %d\n", 
+               dev_path(bus->dev),
+               (bridge->flags & IORESOURCE_IO)? "io":
+               (bridge->flags & IORESOURCE_PREFETCH)? "prefmem" : "mem",
+               base, bridge->size, bridge->align, bridge->gran);
+
        /* We want different minimum alignments for different kinds of
         * resources.  These minimums are not device type specific
         * but resource type specific.
@@ -181,28 +289,22 @@ void compute_allocate_resource(
                min_align = log2(DEVICE_MEM_ALIGN);
        }
 
-       printk_spew("DEV: %02x:%02x.%01x compute_allocate_%s: base: %08lx size: %08lx align: %d gran: %d\n", 
-               bus->bus->secondary,
-               PCI_SLOT(bus->devfn), PCI_FUNC(bus->devfn),
-               (bridge->flags & IORESOURCE_IO)? "io":
-               (bridge->flags & IORESOURCE_PREFETCH)? "prefmem" : "mem",
-               base, bridge->size, bridge->align, bridge->gran);
-
        /* Make certain I have read in all of the resources */
        read_resources(bus);
 
        /* Remember I haven't found anything yet. */
        resource = 0;
 
-       /* Walk through all the devices on the current bus and compute the addresses */
+       /* Walk through all the devices on the current bus and 
+        * compute the addresses.
+        */
        while((dev = largest_resource(bus, &resource, type_mask, type))) {
-               unsigned long size;
+               resource_t size;
                /* Do NOT I repeat do not ignore resources which have zero size.
                 * If they need to be ignored dev->read_resources should not even
                 * return them.   Some resources must be set even when they have
                 * no size.  PCI bridge resources are a good example of this.
                 */
-
                /* Propogate the resource alignment to the bridge register  */
                if (resource->align > bridge->align) {
                        bridge->align = resource->align;
@@ -214,11 +316,28 @@ void compute_allocate_resource(
                if (align < min_align) {
                        align = min_align;
                }
+
+               if (resource->flags & IORESOURCE_FIXED) {
+                       continue;
+               }
+
+               /* Propogate the resource limit to the bridge register */
+               if (bridge->limit > resource->limit) {
+                       bridge->limit = resource->limit;
+               }
+               /* Artificially deny limits between DEVICE_MEM_HIGH and 0xffffffff */
+               if ((bridge->limit > DEVICE_MEM_HIGH) && (bridge->limit <= 0xffffffff)) {
+                       bridge->limit = DEVICE_MEM_HIGH;
+               }
                if (resource->flags & IORESOURCE_IO) {
                        /* Don't allow potential aliases over the
                         * legacy pci expansion card addresses.
+                        * The legacy pci decodes only 10 bits,
+                        * uses 100h - 3ffh. Therefor, only 0 - ff
+                        * can be used out of each 400h block of io
+                        * space.
                         */
-                       if ((base > 0x3ff) && ((base & 0x300) != 0)) {
+                       if ((base & 0x300) != 0) {
                                base = (base & ~0x3ff) + 0x400;
                        }
                        /* Don't allow allocations in the VGA IO range.
@@ -228,23 +347,23 @@ void compute_allocate_resource(
                                base = 0x3e0;
                        }
                }
-               if (((round(base, 1UL << align) + size) -1) <= resource->limit) {
+               if (((round(base, align) + size) -1) <= resource->limit) {
                        /* base must be aligned to size */
-                       base = round(base, 1UL << align);
+                       base = round(base, align);
                        resource->base = base;
-                       resource->flags |= IORESOURCE_SET;
+                       resource->flags |= IORESOURCE_ASSIGNED;
+                       resource->flags &= ~IORESOURCE_STORED;
                        base += size;
                        
                        printk_spew(
-                               "DEV: %02x:%02x.%01x %02x *  [0x%08lx - 0x%08lx] %s\n",
-                               dev->bus->secondary, 
-                               PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn), 
+                               "%s %02x *  [0x%08Lx - 0x%08Lx] %s\n",
+                               dev_path(dev),
                                resource->index, 
-                               resource->base, resource->base + resource->size -1,
+                               resource->base, 
+                               resource->base + resource->size - 1,
                                (resource->flags & IORESOURCE_IO)? "io":
                                (resource->flags & IORESOURCE_PREFETCH)? "prefmem": "mem");
                }
-
        }
        /* A pci bridge resource does not need to be a power
         * of two size, but it does have a minimum granularity.
@@ -252,11 +371,10 @@ void compute_allocate_resource(
         * know not to place something else at an address postitively
         * decoded by the bridge.
         */
-       bridge->size = round(base, 1UL << bridge->gran) - bridge->base;
+       bridge->size = round(base, bridge->gran) - bridge->base;
 
-       printk_spew("DEV: %02x:%02x.%01x compute_allocate_%s: base: %08lx size: %08lx align: %d gran: %d done\n", 
-               bus->bus->secondary,
-               PCI_SLOT(bus->devfn), PCI_FUNC(bus->devfn),
+       printk_spew("%s compute_allocate_%s: base: %08Lx size: %08Lx align: %d gran: %d done\n", 
+               dev_path(bus->dev),
                (bridge->flags & IORESOURCE_IO)? "io":
                (bridge->flags & IORESOURCE_PREFETCH)? "prefmem" : "mem",
                base, bridge->size, bridge->align, bridge->gran);
@@ -264,156 +382,355 @@ void compute_allocate_resource(
 
 }
 
+#if CONFIG_CONSOLE_VGA == 1
+device_t vga_pri = 0;
 static void allocate_vga_resource(void)
 {
+#warning "FIXME modify allocate_vga_resource so it is less pci centric!"
+#warning "This function knows to much about PCI stuff, it should be just a ietrator/visitor."
+
        /* FIXME handle the VGA pallette snooping */
-       struct device *dev, *vga, *bus;
-       bus = vga = 0;
+       struct device *dev, *vga, *vga_onboard, *vga_first, *vga_last;
+       struct bus *bus;
+       bus = 0;
+       vga = 0;
+       vga_onboard = 0;
+       vga_first = 0;
+       vga_last = 0;
        for(dev = all_devices; dev; dev = dev->next) {
-               uint32_t class_revision;
-               class_revision = pci_read_config32(dev, PCI_CLASS_REVISION);
-               if (((class_revision >> 24) == 0x03) && 
-                   ((class_revision >> 16) != 0x380)) {
-                       if (!vga) {
-                               printk_debug("Allocating VGA resource\n");
-                               vga = dev;
-                       }
-                       if (vga == dev) {
-                               /* All legacy VGA cards have MEM & I/O space registers */
-                               dev->command |= PCI_COMMAND_MEMORY | PCI_COMMAND_IO;
-                       } else {
-                               /* It isn't safe to enable other VGA cards */
-                               dev->command &= ~(PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
-                       }
+               if (!dev->enabled) continue;
+               if (((dev->class >> 16) == PCI_BASE_CLASS_DISPLAY) &&
+                       ((dev->class >> 8) != PCI_CLASS_DISPLAY_OTHER)) 
+               {
+                        if (!vga_first) {
+                                if (dev->on_mainboard) {
+                                        vga_onboard = dev;
+                                } else {
+                                        vga_first = dev;
+                                }
+                        } else {
+                                if (dev->on_mainboard) {
+                                        vga_onboard = dev;
+                                } else {
+                                        vga_last = dev;
+                                }
+                        }
+
+                       /* It isn't safe to enable other VGA cards */
+                       dev->command &= ~(PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
                }
        }
+       
+        vga = vga_last;
+
+        if(!vga) {
+                vga = vga_first;
+        }
+
+#if CONFIG_CONSOLE_VGA_ONBOARD_AT_FIRST == 1
+        if (vga_onboard) // will use on board vga as pri
+#else
+        if (!vga) // will use last add on adapter as pri
+#endif
+        {
+                vga = vga_onboard;
+        }
+
+       
        if (vga) {
+               /* vga is first add on card or the only onboard vga */
+               printk_debug("Allocating VGA resource %s\n", dev_path(vga));
+               /* All legacy VGA cards have MEM & I/O space registers */
+               vga->command |= (PCI_COMMAND_MEMORY | PCI_COMMAND_IO);
+               vga_pri = vga;
                bus = vga->bus;
        }
        /* Now walk up the bridges setting the VGA enable */
        while(bus) {
-               uint16_t ctrl;
-               ctrl = pci_read_config16(bus, PCI_BRIDGE_CONTROL);
-               ctrl |= PCI_BRIDGE_CTL_VGA;
-               pci_write_config16(bus, PCI_BRIDGE_CONTROL, ctrl);
-               bus = (bus == bus->bus)? 0 : bus->bus;
+               printk_debug("Setting PCI_BRIDGE_CTL_VGA for bridge %s\n",
+                            dev_path(bus->dev));
+               bus->bridge_ctrl |= PCI_BRIDGE_CTL_VGA;
+               bus = (bus == bus->dev->bus)? 0 : bus->dev->bus;
        } 
 }
 
+#endif
+
 
-/** Assign the computed resources to the bridges and devices on the bus.
- * Recurse to any bridges found on this bus first. Then do the devices
- * on this bus. 
+/**
+ * @brief  Assign the computed resources to the devices on the bus.
+ *
  * @param bus Pointer to the structure for this bus
- */ 
-void assign_resources(struct device *bus)
+ *
+ * Use the device specific set_resources method to store the computed
+ * resources to hardware. For bridge devices, the set_resources() method
+ * has to recurse into every down stream buses.
+ *
+ * Mutual recursion:
+ *     assign_resources() -> device_operation::set_resources()
+ *     device_operation::set_resources() -> assign_resources()
+ */
+void assign_resources(struct bus *bus)
 {
        struct device *curdev;
 
-       printk_debug("ASSIGN RESOURCES, bus %d\n", bus->secondary);
+       printk_spew("%s assign_resources, bus %d link: %d\n", 
+               dev_path(bus->dev), bus->secondary, bus->link);
 
-       for (curdev = bus->children; curdev; curdev = curdev->sibling) {
+       for(curdev = bus->children; curdev; curdev = curdev->sibling) {
+               if (!curdev->enabled || !curdev->resources) {
+                       continue;
+               }
+               if (!curdev->ops || !curdev->ops->set_resources) {
+                       printk_err("%s missing set_resources\n",
+                               dev_path(curdev));
+                       continue;
+               }
                curdev->ops->set_resources(curdev);
        }
-       printk_debug("ASSIGNED RESOURCES, bus %d\n", bus->secondary);
+       printk_spew("%s assign_resources, bus %d link: %d\n", 
+               dev_path(bus->dev), bus->secondary, bus->link);
 }
 
-static void enable_resources(struct device *bus)
+/**
+ * @brief Enable the resources for a specific device
+ *
+ * @param dev the device whose resources are to be enabled
+ *
+ * Enable resources of the device by calling the device specific
+ * enable_resources() method.
+ *
+ * The parent's resources should be enabled first to avoid having enabling
+ * order problem. This is done by calling the parent's enable_resources()
+ * method and let that method to call it's children's enable_resoruces()
+ * method via the (global) enable_childrens_resources().
+ *
+ * Indirect mutual recursion:
+ *     enable_resources() -> device_operations::enable_resource()
+ *     device_operations::enable_resource() -> enable_children_resources()
+ *     enable_children_resources() -> enable_resources()
+ */
+void enable_resources(struct device *dev)
 {
-       struct device *curdev;
+       if (!dev->enabled) {
+               return;
+       }
+       if (!dev->ops || !dev->ops->enable_resources) {
+               printk_err("%s missing enable_resources\n", dev_path(dev));
+               return;
+       }
+       dev->ops->enable_resources(dev);
+}
 
-       /* Walk through the chain of all pci devices and enable them.
-        * This is effectively a breadth first traversal so we should
-        * not have enalbing ordering problems.
-        */
-       for (curdev = all_devices; curdev; curdev = curdev->next) {
-               uint16_t command;
-               command = pci_read_config16(curdev, PCI_COMMAND);
-               command |= curdev->command;
-               printk_debug("DEV: %02x:%02x.%01x cmd <- %02x\n",
-                       curdev->bus->secondary,
-                       PCI_SLOT(curdev->devfn), PCI_FUNC(curdev->devfn),
-                       command);
-               pci_write_config16(curdev, PCI_COMMAND, command);
+/** 
+ * @brief Reset all of the devices a bus
+ *
+ * Reset all of the devices on a bus and clear the bus's reset_needed flag.
+ *
+ * @param bus pointer to the bus structure
+ *
+ * @return 1 if the bus was successfully reset, 0 otherwise.
+ *
+ */
+int reset_bus(struct bus *bus)
+{
+       if (bus && bus->dev && bus->dev->ops && bus->dev->ops->reset_bus)
+       {
+               bus->dev->ops->reset_bus(bus);
+               bus->reset_needed = 0;
+               return 1;
+       }
+       return 0;
+}
+
+/** 
+ * @brief Scan for devices on a bus.
+ *
+ * If there are bridges on the bus, recursively scan the buses behind the bridges.
+ * If the setting up and tuning of the bus causes a reset to be required, 
+ * reset the bus and scan it again.
+ *
+ * @param bus pointer to the bus device
+ * @param max current bus number
+ *
+ * @return The maximum bus number found, after scanning all subordinate busses
+ */
+unsigned int scan_bus(device_t bus, unsigned int max)
+{
+       unsigned int new_max;
+       int do_scan_bus;
+       if (    !bus ||
+               !bus->enabled ||
+               !bus->ops ||
+               !bus->ops->scan_bus)
+       {
+               return max;
        }
+       do_scan_bus = 1;
+       while(do_scan_bus) {
+               int link;
+               new_max = bus->ops->scan_bus(bus, max);
+               do_scan_bus = 0;
+               for(link = 0; link < bus->links; link++) {
+                       if (bus->link[link].reset_needed) {
+                               if (reset_bus(&bus->link[link])) {
+                                       do_scan_bus = 1;
+                               } else {
+                                       bus->bus->reset_needed = 1;
+                               }
+                       }
+               }
+       }
+       return new_max;
 }
 
-/** Enumerate the resources on the PCI by calling pci_init
+
+/**
+ * @brief Determine the existence of devices and extend the device tree.
+ *
+ * Most of the devices in the system are listed in the mainboard Config.lb
+ * file. The device structures for these devices are generated at compile
+ * time by the config tool and are organized into the device tree. This
+ * function determines if the devices created at compile time actually exist
+ * in the physical system.
+ *
+ * For devices in the physical system but not listed in the Config.lb file,
+ * the device structures have to be created at run time and attached to the
+ * device tree.
+ *
+ * This function starts from the root device 'dev_root', scan the buses in
+ * the system recursively, modify the device tree according to the result of
+ * the probe.
+ *
+ * This function has no idea how to scan and probe buses and devices at all.
+ * It depends on the bus/device specific scan_bus() method to do it. The
+ * scan_bus() method also has to create the device structure and attach
+ * it to the device tree. 
  */
 void dev_enumerate(void)
 {
        struct device *root;
-       printk_info("Enumerating buses...");
+       unsigned subordinate;
+       printk_info("Enumerating buses...\n");
        root = &dev_root;
-       if (!root->ops) {
-               root->ops = &default_pci_ops_root;
+       if (root->chip_ops && root->chip_ops->enable_dev) {
+               root->chip_ops->enable_dev(root);
        }
-       root->subordinate = root->ops->scan_bus(root, 0);
+       if (!root->ops || !root->ops->scan_bus) {
+               printk_err("dev_root missing scan_bus operation");
+               return;
+       }
+       subordinate = scan_bus(root, 0);
        printk_info("done\n");
 }
 
-/** Starting at the root, compute what resources are needed and allocate them. 
- * I/O starts at PCI_IO_START. Since the assignment is hierarchical we
- * set the values into the dev_root struct. 
+/**
+ * @brief Configure devices on the devices tree.
+ * 
+ * Starting at the root of the device tree, travel it recursively in two
+ * passes. In the first pass, we compute and allocate resources (ranges)
+ * requried by each device. In the second pass, the resources ranges are
+ * relocated to their final position and stored to the hardware.
+ *
+ * I/O resources start at DEVICE_IO_START and grow upward. MEM resources start
+ * at DEVICE_MEM_START and grow downward.
+ *
+ * Since the assignment is hierarchical we set the values into the dev_root
+ * struct. 
  */
 void dev_configure(void)
 {
-       struct device *root = &dev_root;
-       printk_info("Allocating resources...");
-       printk_debug("\n");
+       struct resource *io, *mem;
+       struct device *root;
 
+       printk_info("Allocating resources...\n");
 
-       root->ops->read_resources(root);
+       root = &dev_root;
+       if (!root->ops || !root->ops->read_resources) {
+               printk_err("dev_root missing read_resources\n");
+               return;
+       }
+       if (!root->ops || !root->ops->set_resources) {
+               printk_err("dev_root missing set_resources\n");
+               return;
+       }
 
-       /* Make certain the io devices are allocated somewhere
-        * safe.
-        */
-       root->resource[0].base = DEVICE_IO_START;
-       root->resource[0].flags |= IORESOURCE_SET;
+       printk_info("Reading resources...\n");
+       root->ops->read_resources(root);
+       printk_info("Done reading resources.\n");
+
+       /* Get the resources */
+       io  = &root->resource[0];
+       mem = &root->resource[1];
+       /* Make certain the io devices are allocated somewhere safe. */
+       io->base = DEVICE_IO_START;
+       io->flags |= IORESOURCE_ASSIGNED;
+       io->flags &= ~IORESOURCE_STORED;
        /* Now reallocate the pci resources memory with the
         * highest addresses I can manage.
         */
-       root->resource[1].base = 
-               round_down(DEVICE_MEM_HIGH - root->resource[1].size,
-                       1UL << root->resource[1].align);
-       root->resource[1].flags |= IORESOURCE_SET;
-       // now just set things into registers ... we hope ...
-       root->ops->set_resources(root);
+       mem->base = resource_max(&root->resource[1]);
+       mem->flags |= IORESOURCE_ASSIGNED;
+       mem->flags &= ~IORESOURCE_STORED;
 
-       allocate_vga_resource();
+#if CONFIG_CONSOLE_VGA == 1
+       /* Allocate the VGA I/O resource.. */
+       allocate_vga_resource(); 
+#endif
 
-       printk_info("done.\n");
+       /* Store the computed resource allocations into device registers ... */
+       printk_info("Setting resources...\n");
+       root->ops->set_resources(root);
+       printk_info("Done setting resources.\n");
+#if 0
+       mem->flags |= IORESOURCE_STORED;
+       report_resource_stored(root, mem, "");
+#endif
+
+       printk_info("Done allocating resources.\n");
 }
 
-/** Starting at the root, walk the tree and enable all devices/bridges. 
- * What really happens is computed COMMAND bits get set in register 4
+/**
+ * @brief Enable devices on the device tree.
+ *
+ * Starting at the root, walk the tree and enable all devices/bridges by
+ * calling the device's enable_resources() method.
  */
 void dev_enable(void)
 {
-       printk_info("Enabling resourcess...");
+       printk_info("Enabling resources...\n");
 
        /* now enable everything. */
        enable_resources(&dev_root);
+
        printk_info("done.\n");
 }
 
-/** Starting at the root, walk the tree and call a driver to
- *  do device specific setup.
+/**
+ * @brief Initialize all devices in the global device list.
+ *
+ * Starting at the first device on the global device link list,
+ * walk the list and call the device's init() method to do deivce
+ * specific setup.
  */
 void dev_initialize(void)
 {
        struct device *dev;
 
        printk_info("Initializing devices...\n");
-       for (dev = all_devices; dev; dev = dev->next) {
-               if (dev->ops->init) {
-                       printk_debug("PCI: %02x:%02x.%01x init\n",
-                               dev->bus->secondary,
-                               PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn));
+       for(dev = all_devices; dev; dev = dev->next) {
+               if (dev->enabled && !dev->initialized && 
+                       dev->ops && dev->ops->init) 
+               {
+                       if (dev->path.type == DEVICE_PATH_I2C) {
+                               printk_debug("smbus: %s[%d]->",
+                                       dev_path(dev->bus->dev), dev->bus->link);
+                       }
+                       printk_debug("%s init\n", dev_path(dev));
+                       dev->initialized = 1;
                        dev->ops->init(dev);
                }
        }
        printk_info("Devices initialized\n");
 }
 
-