ChangeSet 1.793.1.17, 2002/10/18 10:00:13-07:00, greg@kroah.com

merge between the usb and driver model trees.


diff -Nru a/drivers/base/core.c b/drivers/base/core.c
--- a/drivers/base/core.c	Fri Oct 18 14:43:06 2002
+++ b/drivers/base/core.c	Fri Oct 18 14:43:06 2002
@@ -19,109 +19,12 @@
 int (*platform_notify)(struct device * dev) = NULL;
 int (*platform_notify_remove)(struct device * dev) = NULL;
 
+DECLARE_MUTEX(device_sem);
+
 spinlock_t device_lock = SPIN_LOCK_UNLOCKED;
 
 #define to_dev(node) container_of(node,struct device,driver_list)
 
-static int probe(struct device * dev, struct device_driver * drv)
-{
-	dev->driver = drv;
-	return drv->probe ? drv->probe(dev) : -ENODEV;
-}
-
-static void attach(struct device * dev)
-{
-	spin_lock(&device_lock);
-	list_add_tail(&dev->driver_list,&dev->driver->devices);
-	spin_unlock(&device_lock);
-	devclass_add_device(dev);
-}
-
-/**
- * found_match - do actual binding of device to driver
- * @dev:	device 
- * @drv:	driver
- *
- * We're here because the bus's match callback returned success for this 
- * pair. We call the driver's probe callback to verify they're really a
- * match made in heaven.
- *
- * In the future, we may want to notify userspace of the binding. (But, 
- * we might not want to do it here).
- * 
- * We may also want to create a symlink in the driver's directory to the 
- * device's physical directory.
- */
-static int found_match(struct device * dev, struct device_driver * drv)
-{
-	int error;
-
-	if (!(error = probe(dev,get_driver(drv)))) {
-		pr_debug("bound device '%s' to driver '%s'\n",
-			 dev->bus_id,drv->name);
-		attach(dev);
-	} else {
-		put_driver(drv);
-		dev->driver = NULL;
-	}
-	/* return boolean:  did driver bind? */
-	return error == 0;
-}
-
-/**
- * device_attach - try to associated device with a driver
- * @drv:	current driver to try
- * @data:	device in disguise
- *
- * This function is used as a callback to bus_for_each_drv.
- * It calls the bus's match callback to check if the driver supports
- * the device. If so, it calls the found_match() function above to 
- * take care of all the details.
- */
-static int do_device_attach(struct device_driver * drv, void * data)
-{
-	struct device * dev = (struct device *)data;
-	int error = 0;
-
-	if (drv->bus->match && drv->bus->match(dev,drv))
-		error = found_match(dev,drv);
-	/* stop bus_for_each_drv() once a driver binds to the device */
-	return error;
-}
-
-static int device_attach(struct device * dev)
-{
-	int error = 0;
-	if (!dev->driver) {
-		if (dev->bus)
-			error = bus_for_each_drv(dev->bus,dev,do_device_attach);
-	} else
-		attach(dev);
-	return error;
-}
-
-static void device_detach(struct device * dev)
-{
-	struct device_driver * drv = dev->driver;
-
-	if (drv) {
-		devclass_remove_device(dev);
-		if (drv && drv->remove)
-			drv->remove(dev);
-		dev->driver = NULL;
-	}
-}
-
-static int do_driver_attach(struct device * dev, void * data)
-{
-	struct device_driver * drv = (struct device_driver *)data;
-
-	if (!dev->driver) {
-		if (dev->bus->match && dev->bus->match(dev,drv))
-			found_match(dev,drv);
-	}
-	/* continue bus_for_each_dev(), to attach to other devices */
-	return 0;
 }
 
 int driver_attach(struct device_driver * drv)
@@ -162,30 +65,21 @@
  * Maintains a global list of all devices, in depth-first ordering.
  * The head for that list is device_root.g_list.
  */
-int device_register(struct device *dev)
+int device_add(struct device *dev)
 {
 	int error;
 
 	if (!dev || !strlen(dev->bus_id))
 		return -EINVAL;
 
-	INIT_LIST_HEAD(&dev->node);
-	INIT_LIST_HEAD(&dev->children);
-	INIT_LIST_HEAD(&dev->g_list);
-	INIT_LIST_HEAD(&dev->driver_list);
-	INIT_LIST_HEAD(&dev->bus_list);
-	INIT_LIST_HEAD(&dev->intf_list);
-	spin_lock_init(&dev->lock);
-	atomic_set(&dev->refcount,2);
-	dev->present = 1;
-	spin_lock(&device_lock);
+	down(&device_sem);
+	dev->state = DEVICE_REGISTERED;
 	if (dev->parent) {
-		get_device_locked(dev->parent);
 		list_add_tail(&dev->g_list,&dev->parent->g_list);
 		list_add_tail(&dev->node,&dev->parent->children);
 	} else
 		list_add_tail(&dev->g_list,&global_device_list);
-	spin_unlock(&device_lock);
+	up(&device_sem);
 
 	pr_debug("DEV: registering device: ID = '%s', name = %s\n",
 		 dev->bus_id, dev->name);
@@ -195,9 +89,6 @@
 
 	bus_add_device(dev);
 
-	/* bind to driver */
-	device_attach(dev);
-
 	/* notify platform of device entry */
 	if (platform_notify)
 		platform_notify(dev);
@@ -205,35 +96,68 @@
 	/* notify userspace of device entry */
 	dev_hotplug(dev, "add");
 
+	devclass_add_device(dev);
  register_done:
 	if (error) {
-		spin_lock(&device_lock);
+		up(&device_sem);
 		list_del_init(&dev->g_list);
 		list_del_init(&dev->node);
-		spin_unlock(&device_lock);
-		if (dev->parent)
-			put_device(dev->parent);
+		up(&device_sem);
 	}
-	put_device(dev);
 	return error;
 }
 
-struct device * get_device_locked(struct device * dev)
+void device_initialize(struct device *dev)
 {
-	struct device * ret = dev;
-	if (dev && dev->present && atomic_read(&dev->refcount) > 0)
-		atomic_inc(&dev->refcount);
-	else
-		ret = NULL;
-	return ret;
+	INIT_LIST_HEAD(&dev->node);
+	INIT_LIST_HEAD(&dev->children);
+	INIT_LIST_HEAD(&dev->g_list);
+	INIT_LIST_HEAD(&dev->driver_list);
+	INIT_LIST_HEAD(&dev->bus_list);
+	INIT_LIST_HEAD(&dev->intf_list);
+	spin_lock_init(&dev->lock);
+	atomic_set(&dev->refcount,1);
+	dev->state = DEVICE_INITIALIZED;
+	if (dev->parent)
+		get_device(dev->parent);
+}
+
+/**
+ * device_register - register a device
+ * @dev:	pointer to the device structure
+ *
+ * First, make sure that the device has a parent, create
+ * a directory for it, then add it to the parent's list of
+ * children.
+ *
+ * Maintains a global list of all devices, in depth-first ordering.
+ * The head for that list is device_root.g_list.
+ */
+int device_register(struct device *dev)
+{
+	int error;
+
+	if (!dev || !strlen(dev->bus_id))
+		return -EINVAL;
+
+	device_initialize(dev);
+	if (dev->parent)
+		get_device(dev->parent);
+	error = device_add(dev);
+	if (error && dev->parent)
+		put_device(dev->parent);
+	return error;
 }
 
 struct device * get_device(struct device * dev)
 {
-	struct device * ret;
-	spin_lock(&device_lock);
-	ret = get_device_locked(dev);
-	spin_unlock(&device_lock);
+	struct device * ret = dev;
+	down(&device_sem);
+	if (device_present(dev) && atomic_read(&dev->refcount) > 0)
+		atomic_inc(&dev->refcount);
+	else
+		ret = NULL;
+	up(&device_sem);
 	return ret;
 }
 
@@ -243,43 +167,23 @@
  */
 void put_device(struct device * dev)
 {
-	struct device * parent;
-	if (!atomic_dec_and_lock(&dev->refcount,&device_lock))
+	down(&device_sem);
+	if (!atomic_dec_and_test(&dev->refcount)) {
+		up(&device_sem);
 		return;
-	parent = dev->parent;
-	dev->parent = NULL;
-	spin_unlock(&device_lock);
-
-	BUG_ON(dev->present);
+	}
+	list_del_init(&dev->node);
+	list_del_init(&dev->g_list);
+	up(&device_sem);
 
-	if (dev->release)
-		dev->release(dev);
+	BUG_ON((dev->state != DEVICE_GONE));
 
-	if (parent)
-		put_device(parent);
+	device_del(dev);
 }
 
-/**
- * device_unregister - unlink device
- * @dev:	device going away
- *
- * The device has been removed from the system, so we disavow knowledge
- * of it. It might not be the final reference to the device, so we mark
- * it as !present, so no more references to it can be acquired.
- * In the end, we decrement the final reference count for it.
- */
-void device_unregister(struct device * dev)
+void device_del(struct device * dev)
 {
-	spin_lock(&device_lock);
-	dev->present = 0;
-	list_del_init(&dev->node);
-	list_del_init(&dev->g_list);
-	list_del_init(&dev->bus_list);
-	list_del_init(&dev->driver_list);
-	spin_unlock(&device_lock);
-
-	pr_debug("DEV: Unregistering device. ID = '%s', name = '%s'\n",
-		 dev->bus_id,dev->name);
+	struct device * parent = dev->parent;
 
 	/* Notify the platform of the removal, in case they
 	 * need to do anything...
@@ -290,26 +194,37 @@
 	/* notify userspace that this device is about to disappear */
 	dev_hotplug (dev, "remove");
 
-	device_detach(dev);
 	bus_remove_device(dev);
 
 	/* remove the driverfs directory */
 	device_remove_dir(dev);
 
-	put_device(dev);
+	if (dev->release)
+		dev->release(dev);
+
+	if (parent)
+		put_device(parent);
 }
 
-static int __init device_init(void)
+/**
+ * device_unregister - unlink device
+ * @dev:	device going away
+ *
+ * The device has been removed from the system, so we disavow knowledge
+ * of it. It might not be the final reference to the device, so we mark
+ * it as !present, so no more references to it can be acquired.
+ * In the end, we decrement the final reference count for it.
+ */
+void device_unregister(struct device * dev)
 {
-	int error;
+	down(&device_sem);
+	dev->state = DEVICE_GONE;
+	up(&device_sem);
 
-	error = init_driverfs_fs();
-	if (error)
-		panic("DEV: could not initialize driverfs");
-	return 0;
+	pr_debug("DEV: Unregistering device. ID = '%s', name = '%s'\n",
+		 dev->bus_id,dev->name);
+	put_device(dev);
 }
-
-core_initcall(device_init);
 
 EXPORT_SYMBOL(device_register);
 EXPORT_SYMBOL(device_unregister);