driver model: convert drivers to use kobject and sysfs.

- add kobject to struct device_driver and register it when drivers are registered
  (as member's of their bus's driver subsystem).
- convert driverfs callbacks to know about struct kobject.
- create links from drivers' directories to devices' directories.
- don't even make driverfs directories for drivers anymore. 

drivers/base/bus.c

@@ -24,7 +24,47 @@ static LIST_HEAD(bus_driver_list);
 #define to_bus(obj) container_of(obj,struct bus_type,subsys.kobj)
 
 /*
- * sysfs bindings for buses
+ * sysfs bindings for drivers
+ */
+
+#define to_drv_attr(_attr) container_of(_attr,struct driver_attribute,attr)
+#define to_driver(obj) container_of(obj, struct device_driver, kobj)
+
+
+static ssize_t
+drv_attr_show(struct kobject * kobj, struct attribute * attr,
+	      char * buf, size_t count, loff_t off)
+{
+	struct driver_attribute * drv_attr = to_drv_attr(attr);
+	struct device_driver * drv = to_driver(kobj);
+	ssize_t ret = 0;
+
+	if (drv_attr->show)
+		ret = drv_attr->show(drv,buf,count,off);
+	return ret;
+}
+
+static ssize_t
+drv_attr_store(struct kobject * kobj, struct attribute * attr,
+	       const char * buf, size_t count, loff_t off)
+{
+	struct driver_attribute * drv_attr = to_drv_attr(attr);
+	struct device_driver * drv = to_driver(kobj);
+	ssize_t ret = 0;
+
+	if (drv_attr->store)
+		ret = drv_attr->store(drv,buf,count,off);
+	return ret;
+}
+
+static struct sysfs_ops driver_sysfs_ops = {
+	.show	= drv_attr_show,
+	.store	= drv_attr_store,
+};
+
+
+/*
+ * sysfs bindings for drivers
  */
 
 
@@ -156,6 +196,7 @@ static void attach(struct device * dev)
 	pr_debug("bound device '%s' to driver '%s'\n",
 		 dev->bus_id,dev->driver->name);
 	list_add_tail(&dev->driver_list,&dev->driver->devices);
+	sysfs_create_link(&dev->driver->kobj,&dev->kobj,dev->kobj.name);
 }
 
 static int bus_match(struct device * dev, struct device_driver * drv)
@@ -226,6 +267,7 @@ static int driver_attach(struct device_driver * drv)
 static void detach(struct device * dev, struct device_driver * drv)
 {
 	if (drv) {
+		sysfs_remove_link(&drv->kobj,dev->kobj.name);
 		list_del_init(&dev->driver_list);
 		devclass_remove_device(dev);
 		if (drv->remove)
@@ -304,7 +346,6 @@ int bus_add_driver(struct device_driver * drv)
 		list_add_tail(&drv->bus_list,&bus->drivers);
 		driver_attach(drv);
 		up_write(&bus->rwsem);
-		driver_make_dir(drv);
 	}
 	return 0;
 }
@@ -360,6 +401,7 @@ int bus_register(struct bus_type * bus)
 
 	snprintf(bus->drvsubsys.kobj.name,KOBJ_NAME_LEN,"drivers");
 	bus->drvsubsys.parent = &bus->subsys;
+	bus->drvsubsys.sysfs_ops = &driver_sysfs_ops;
 	subsystem_register(&bus->drvsubsys);
 
 	spin_lock(&device_lock);

drivers/base/driver.c

@@ -12,6 +12,29 @@
 
 #define to_dev(node) container_of(node,struct device,driver_list)
 
+/*
+ * helpers for creating driver attributes in sysfs
+ */
+
+int driver_create_file(struct device_driver * drv, struct driver_attribute * attr)
+{
+	int error;
+	if (get_driver(drv)) {
+		error = sysfs_create_file(&drv->kobj,&attr->attr);
+		put_driver(drv);
+	} else
+		error = -EINVAL;
+	return error;
+}
+
+void driver_remove_file(struct device_driver * drv, struct driver_attribute * attr)
+{
+	if (get_driver(drv)) {
+		sysfs_remove_file(&drv->kobj,&attr->attr);
+		put_driver(drv);
+	}
+}
+
 int driver_for_each_dev(struct device_driver * drv, void * data, 
 			int (*callback)(struct device *, void * ))
 {
@@ -65,7 +88,6 @@ void put_driver(struct device_driver * drv)
 		return;
 	spin_unlock(&device_lock);
 	BUG_ON(drv->present);
-	bus_remove_driver(drv);
 	if (drv->release)
 		drv->release(drv);
 	put_bus(bus);
@@ -84,6 +106,11 @@ int driver_register(struct device_driver * drv)
 
 	pr_debug("driver %s:%s: registering\n",drv->bus->name,drv->name);
 
+	kobject_init(&drv->kobj);
+	strncpy(drv->kobj.name,drv->name,KOBJ_NAME_LEN);
+	drv->kobj.subsys = &drv->bus->drvsubsys;
+	kobject_register(&drv->kobj);
+
 	get_bus(drv->bus);
 	atomic_set(&drv->refcount,2);
 	rwlock_init(&drv->lock);
@@ -108,3 +135,6 @@ EXPORT_SYMBOL(driver_register);
 EXPORT_SYMBOL(driver_unregister);
 EXPORT_SYMBOL(get_driver);
 EXPORT_SYMBOL(put_driver);
+
+EXPORT_SYMBOL(driver_create_file);
+EXPORT_SYMBOL(driver_remove_file);

drivers/base/fs/driver.c

@@ -4,80 +4,6 @@
 #include <linux/err.h>
 #include "fs.h"
 
-#define to_drv_attr(_attr) container_of(_attr,struct driver_attribute,attr)
-
-#define to_drv(d) container_of(d, struct device_driver, dir)
-
-
-/* driverfs ops for device attribute files */
-
-static int
-drv_attr_open(struct driver_dir_entry * dir)
-{
-	struct device_driver * drv = to_drv(dir);
-	get_driver(drv);
-	return 0;
-}
-
-static int
-drv_attr_close(struct driver_dir_entry * dir)
-{
-	struct device_driver * drv = to_drv(dir);
-	put_driver(drv);
-	return 0;
-}
-
-static ssize_t
-drv_attr_show(struct driver_dir_entry * dir, struct attribute * attr,
-	      char * buf, size_t count, loff_t off)
-{
-	struct driver_attribute * drv_attr = to_drv_attr(attr);
-	struct device_driver * drv = to_drv(dir);
-	ssize_t ret = 0;
-
-	if (drv_attr->show)
-		ret = drv_attr->show(drv,buf,count,off);
-	return ret;
-}
-
-static ssize_t
-drv_attr_store(struct driver_dir_entry * dir, struct attribute * attr,
-	       const char * buf, size_t count, loff_t off)
-{
-	struct driver_attribute * drv_attr = to_drv_attr(attr);
-	struct device_driver * drv = to_drv(dir);
-	ssize_t ret = 0;
-
-	if (drv_attr->store)
-		ret = drv_attr->store(drv,buf,count,off);
-	return ret;
-}
-
-static struct driverfs_ops drv_attr_ops = {
-	.open	= drv_attr_open,
-	.close	= drv_attr_close,
-	.show	= drv_attr_show,
-	.store	= drv_attr_store,
-};
-
-int driver_create_file(struct device_driver * drv, struct driver_attribute * attr)
-{
-	int error;
-	if (get_driver(drv)) {
-		error = driverfs_create_file(&attr->attr,&drv->dir);
-		put_driver(drv);
-	} else
-		error = -EINVAL;
-	return error;
-}
-
-void driver_remove_file(struct device_driver * drv, struct driver_attribute * attr)
-{
-	if (get_driver(drv)) {
-		driverfs_remove_file(&drv->dir,attr->attr.name);
-		put_driver(drv);
-	}
-}
 
 /**
  * driver_make_dir - create a driverfs directory for a driver
@@ -86,8 +12,6 @@ void driver_remove_file(struct device_driver * drv, struct driver_attribute * at
 int driver_make_dir(struct device_driver * drv)
 {
 	drv->dir.name = drv->name;
-	drv->dir.ops = &drv_attr_ops;
-
 	return device_create_dir(&drv->dir,&drv->bus->driver_dir);
 }
 
@@ -96,5 +20,3 @@ void driver_remove_dir(struct device_driver * drv)
 	driverfs_remove_dir(&drv->dir);
 }
 
-EXPORT_SYMBOL(driver_create_file);
-EXPORT_SYMBOL(driver_remove_file);

include/linux/device.h

@@ -123,6 +123,7 @@ struct device_driver {
 	atomic_t		refcount;
 	u32			present;
 
+	struct kobject		kobj;
 	struct list_head	bus_list;
 	struct list_head	class_list;
 	struct list_head	devices;