1 files changed, 112 insertions, 61 deletions

diff --git a/src/devices/device.c b/src/devices/device.c
index b54e770294..0186aa977a 100644
--- a/src/devices/device.c
+++ b/src/devices/device.c
@@ -22,24 +22,41 @@
 #include <stdlib.h>
 #include <string.h>
 
-/* Linked list of ALL devices */
+/** Linked list of ALL devices */
 struct device *all_devices = &dev_root;
-/* pointer to the last device */
+/** Pointer to the last device */
 static struct device **last_dev_p = &dev_root.next;
 
-#define DEVICE_MEM_HIGH  0xFEC00000UL /* Reserve 20M for the system */
+/** The upper limit of MEM resource of the devices.
+ * Reserve 20M for the system */
+#define DEVICE_MEM_HIGH 0xFEC00000UL
+/** The lower limit of IO resource of the devices.
+ * Reserve 4k for ISA/Legacy devices */
 #define DEVICE_IO_START 0x1000
 
-/** Allocate a new device structure
+/**
+ * @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
  */
 device_t alloc_dev(struct bus *parent, struct device_path *path)
 {
 	device_t dev, child;
 	int link;
+
 	/* Find the last child of our parent */
-	for(child = parent->children; child && child->sibling; ) {
+	for (child = parent->children; child && child->sibling; ) {
 		child = child->sibling;
 	}
+
 	dev = malloc(sizeof(*dev));
 	if (dev == 0) {
 		die("DEV: out of memory.\n");
@@ -47,14 +64,14 @@ device_t alloc_dev(struct bus *parent, struct device_path *path)
 	memset(dev, 0, sizeof(*dev));
 	memcpy(&dev->path, path, sizeof(*path));
 
-	/* Append a new device to the global device chain.
-	 * The chain is used to find devices once everything is set up.
+	/* 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;
 
 	/* Initialize the back pointers in the link fields */
-	for(link = 0; link < MAX_LINKS; link++) {
+	for (link = 0; link < MAX_LINKS; link++) {
 		dev->link[link].dev  = dev;
 		dev->link[link].link = link;
 	}
@@ -66,12 +83,15 @@ device_t alloc_dev(struct bus *parent, struct device_path *path)
 	} else {
 		parent->children = dev;
 	}
+
 	/* If we don't have any other information about a device enable it */
 	dev->enable = 1;
+
 	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
@@ -104,7 +124,7 @@ static void read_resources(struct bus *bus)
 	struct device *curdev;
 
 	/* Walk through all of the devices and find which resources they need. */
-	for(curdev = bus->children; curdev; curdev = curdev->sibling) {
+	for (curdev = bus->children; curdev; curdev = curdev->sibling) {
 		unsigned links;
 		int i;
 		if (curdev->resources > 0) {
@@ -112,20 +132,22 @@ static void read_resources(struct bus *bus)
 		}
 		if (!curdev->ops || !curdev->ops->read_resources) {
 			printk_err("%s missing read_resources\n",
-				dev_path(curdev));
+				   dev_path(curdev));
 			continue;
 		}
 		if (!curdev->enable) {
 			continue;
 		}
+
 		curdev->ops->read_resources(curdev);
+
 		/* Read in subtractive resources behind the current device */
 		links = 0;
-		for(i = 0; i < curdev->resources; i++) {
+		for (i = 0; i < curdev->resources; i++) {
 			struct resource *resource;
 			resource = &curdev->resource[i];
 			if ((resource->flags & IORESOURCE_SUBTRACTIVE) &&
-				(!(links & (1 << resource->index))))
+			    (!(links & (1 << resource->index))))
 			{
 				links |= (1 << resource->index);
 				read_resources(&curdev->link[resource->index]);
@@ -142,8 +164,8 @@ struct pick_largest_state {
 	int seen_last;
 };
 
-static void pick_largest_resource(
-	struct pick_largest_state *state, struct device *dev, struct resource *resource)
+static void pick_largest_resource(struct pick_largest_state *state,
+				  struct device *dev, struct resource *resource)
 {
 	struct resource *last;
 	last = state->last;
@@ -152,32 +174,33 @@ static void pick_largest_resource(
 		state->seen_last = 1;
 		return;
 	}
-	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)))) {
+	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))) {
+	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 void find_largest_resource(struct pick_largest_state *state, 
-	struct bus *bus, unsigned long type_mask, unsigned long type)
+				  struct bus *bus, unsigned long type_mask,
+				  unsigned long type)
 {
 	struct device *curdev;
-	for(curdev = bus->children; curdev; curdev = curdev->sibling) {
+
+	for (curdev = bus->children; curdev; curdev = curdev->sibling) {
 		int i;
-		for(i = 0; i < curdev->resources; i++) {
+		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) {
@@ -187,7 +210,8 @@ static void find_largest_resource(struct pick_largest_state *state,
 			if (resource->flags & IORESOURCE_SUBTRACTIVE) {
 				struct bus *subbus;
 				subbus = &curdev->link[resource->index];
-				find_largest_resource(state, subbus, type_mask, type);
+				find_largest_resource(state, subbus,
+						      type_mask, type);
 				continue;
 			}
 			/* See if this is the largest resource */
@@ -196,8 +220,10 @@ static void find_largest_resource(struct pick_largest_state *state,
 	}
 }
 
-static struct device *largest_resource(struct bus *bus, struct resource **result_res,
-	unsigned long type_mask, unsigned long type)
+static struct device *largest_resource(struct bus *bus,
+				       struct resource **result_res,
+				       unsigned long type_mask,
+				       unsigned long type)
 {
 	struct pick_largest_state state;
 
@@ -254,12 +280,12 @@ void compute_allocate_resource(
 	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);
-
+	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
@@ -278,8 +304,9 @@ void compute_allocate_resource(
 	/* Remember I haven't found anything yet. */
 	resource = 0;
 
-	/* Walk through all the devices on the current bus and compute the addresses */
-	while((dev = largest_resource(bus, &resource, type_mask, type))) {
+	/* 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;
 		/* Do NOT I repeat do not ignore resources which have zero size.
 		 * If they need to be ignored dev->read_resources should not even
@@ -357,6 +384,8 @@ void compute_allocate_resource(
 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;
 	struct bus *bus;
@@ -422,7 +451,7 @@ void enable_resources(struct device *dev)
 	 */
 	if (!dev->ops || !dev->ops->enable_resources) {
 		printk_err("%s missing enable_resources\n",
-			dev_path(dev));
+			   dev_path(dev));
 		return;
 	}
 	if (!dev->enable) {
@@ -431,58 +460,74 @@ void enable_resources(struct device *dev)
 	dev->ops->enable_resources(dev);
 }
 
-/** Enumerate the resources on the PCI by calling pci_init
+/**
+ * @brief Determine the existence of dynamic devices and construct dynamic
+ * device tree.
+ *
+ * Start for the root device 'dev_root', scan the buses in the system, build
+ * the dynamic device tree according to the result of the probe.
+ *
+ * This function have no idea how to scan and probe the buses and devices at
+ * all. It depends on the bus/device specific scan_bus() method to do it.
+ * The scan_bus() function also have to create the device structure and attach
+ * it to the device tree. 
  */
 void dev_enumerate(void)
 {
 	struct device *root;
 	unsigned subordinate;
-	printk_info("Enumerating buses...");
+
+	printk_info("Enumerating buses...\n");
+
 	root = &dev_root;
 	subordinate = root->ops->scan_bus(root, 0);
+
 	printk_info("done\n");
 }
 
-/** Starting at the root, compute what resources are needed and allocate them. 
+/**
+ * @brief Configure devices on the devices tree.
+ * 
+ * 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. 
  */
 void dev_configure(void)
 {
 	struct device *root = &dev_root;
+
 	printk_info("Allocating resources...");
 	printk_debug("\n");
 
-
 	root->ops->read_resources(root);
 
-	/* Make certain the io devices are allocated somewhere
-	 * safe.
-	 */
+	/* Make certain the io devices are allocated somewhere safe. */
 	root->resource[0].base = DEVICE_IO_START;
 	root->resource[0].flags |= IORESOURCE_ASSIGNED;
 	root->resource[0].flags &= ~IORESOURCE_STORED;
-	/* Now reallocate the pci resources memory with the
-	 * highest addresses I can manage.
-	 */
+
+	/* 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);
+			   1UL << root->resource[1].align);
 	root->resource[1].flags |= IORESOURCE_ASSIGNED;
 	root->resource[1].flags &= ~IORESOURCE_STORED;
 
-	/* Allocate the VGA I/O resource..
-	 */
+	/* Allocate the VGA I/O resource.. */
 	allocate_vga_resource(); 
 
-	// now just set things into registers ... we hope ...
+	/* now just set things into registers ... we hope ... */
 	root->ops->set_resources(root);
 
 	printk_info("done.\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)
 {
@@ -490,22 +535,28 @@ void dev_enable(void)
 
 	/* 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 a driver to do device specific setup.
  */
 void dev_initialize(void)
 {
 	struct device *dev;
 
 	printk_info("Initializing devices...\n");
+
 	for (dev = all_devices; dev; dev = dev->next) {
 		if (dev->enable && dev->ops && dev->ops->init) {
 			printk_debug("%s init\n", dev_path(dev));
 			dev->ops->init(dev);
 		}
 	}
+
 	printk_info("Devices initialized\n");
 }