Merge branch 'linus' into x86/urgent

[mv-sheeva.git] / drivers / base / class.c

diff --git a/drivers/base/class.c b/drivers/base/class.c
index eb85e4312301aca04f01e4898c79b1269bc0d2a4..161746deab4baabb00bebdf4fb0991bbdf693f7f 100644 (file)
--- a/drivers/base/class.c
+++ b/drivers/base/class.c
@@ -488,6 +488,93 @@ void class_interface_unregister(struct class_interface *class_intf)
        class_put(parent);
 }
 
+struct class_compat {
+       struct kobject *kobj;
+};
+
+/**
+ * class_compat_register - register a compatibility class
+ * @name: the name of the class
+ *
+ * Compatibility class are meant as a temporary user-space compatibility
+ * workaround when converting a family of class devices to a bus devices.
+ */
+struct class_compat *class_compat_register(const char *name)
+{
+       struct class_compat *cls;
+
+       cls = kmalloc(sizeof(struct class_compat), GFP_KERNEL);
+       if (!cls)
+               return NULL;
+       cls->kobj = kobject_create_and_add(name, &class_kset->kobj);
+       if (!cls->kobj) {
+               kfree(cls);
+               return NULL;
+       }
+       return cls;
+}
+EXPORT_SYMBOL_GPL(class_compat_register);
+
+/**
+ * class_compat_unregister - unregister a compatibility class
+ * @cls: the class to unregister
+ */
+void class_compat_unregister(struct class_compat *cls)
+{
+       kobject_put(cls->kobj);
+       kfree(cls);
+}
+EXPORT_SYMBOL_GPL(class_compat_unregister);
+
+/**
+ * class_compat_create_link - create a compatibility class device link to
+ *                           a bus device
+ * @cls: the compatibility class
+ * @dev: the target bus device
+ * @device_link: an optional device to which a "device" link should be created
+ */
+int class_compat_create_link(struct class_compat *cls, struct device *dev,
+                            struct device *device_link)
+{
+       int error;
+
+       error = sysfs_create_link(cls->kobj, &dev->kobj, dev_name(dev));
+       if (error)
+               return error;
+
+       /*
+        * Optionally add a "device" link (typically to the parent), as a
+        * class device would have one and we want to provide as much
+        * backwards compatibility as possible.
+        */
+       if (device_link) {
+               error = sysfs_create_link(&dev->kobj, &device_link->kobj,
+                                         "device");
+               if (error)
+                       sysfs_remove_link(cls->kobj, dev_name(dev));
+       }
+
+       return error;
+}
+EXPORT_SYMBOL_GPL(class_compat_create_link);
+
+/**
+ * class_compat_remove_link - remove a compatibility class device link to
+ *                           a bus device
+ * @cls: the compatibility class
+ * @dev: the target bus device
+ * @device_link: an optional device to which a "device" link was previously
+ *              created
+ */
+void class_compat_remove_link(struct class_compat *cls, struct device *dev,
+                             struct device *device_link)
+{
+       if (device_link)
+               sysfs_remove_link(&dev->kobj, "device");
+       sysfs_remove_link(cls->kobj, dev_name(dev));
+}
+EXPORT_SYMBOL_GPL(class_compat_remove_link);
+
 int __init classes_init(void)
 {
        class_kset = kset_create_and_add("class", NULL, NULL);