1 files changed, 70 insertions, 0 deletions
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
new file mode 100644
index 000000000000..13a7038c4826
--- /dev/null
+++ b/drivers/base/driver.c
@@ -0,0 +1,70 @@
+/*
+ * driver.c - centralized device driver management
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include "base.h"
+
+/**
+ * driver_make_dir - create a driverfs directory for a driver
+ * @drv:	driver in question
+ */
+static int driver_make_dir(struct device_driver * drv)
+{
+	drv->dir.name = drv->name;
+	return device_create_dir(&drv->dir,&drv->bus->driver_dir);
+}
+
+/**
+ * driver_register - register driver with bus
+ * @drv:	driver to register
+ * 
+ * Add to bus's list of devices
+ */
+int driver_register(struct device_driver * drv)
+{
+	if (!drv->bus)
+		return -EINVAL;
+
+	pr_debug("Registering driver '%s' with bus '%s'\n",drv->name,drv->bus->name);
+
+	get_bus(drv->bus);
+	atomic_set(&drv->refcount,2);
+	rwlock_init(&drv->lock);
+	write_lock(&drv->bus->lock);
+	list_add(&drv->bus_list,&drv->bus->drivers);
+	write_unlock(&drv->bus->lock);
+	driver_make_dir(drv);
+	put_driver(drv);
+	return 0;
+}
+
+/**
+ * put_driver - decrement driver's refcount and clean up if necessary
+ * @drv:	driver in question
+ */
+void put_driver(struct device_driver * drv)
+{
+	if (!atomic_dec_and_lock(&drv->refcount,&device_lock))
+		return;
+	spin_unlock(&device_lock);
+
+	if (drv->bus) {
+		pr_debug("Unregistering driver '%s' from bus '%s'\n",drv->name,drv->bus->name);
+
+		write_lock(&drv->bus->lock);
+		list_del_init(&drv->bus_list);
+		write_unlock(&drv->bus->lock);
+
+		driverfs_remove_dir(&drv->dir);
+		put_bus(drv->bus);
+	}
+	if (drv->release)
+		drv->release(drv);
+}
+
+EXPORT_SYMBOL(driver_register);
+EXPORT_SYMBOL(put_driver);