driver core: Introduce default attribute groups.

This is lot like default attributes for devices (and indeed,
a lot of the code is lifted from there).

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 42 insertions, 1 deletions

diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index f94be40646d2..e3b58407fedc 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -142,6 +142,37 @@ void put_driver(struct device_driver * drv)
         kobject_put(&drv->kobj);
 }
 
+static int driver_add_groups(struct device_driver *drv,
+                             struct attribute_group **groups)
+{
+        int error = 0;
+        int i;
+
+        if (groups) {
+                for (i = 0; groups[i]; i++) {
+                        error = sysfs_create_group(&drv->kobj, groups[i]);
+                        if (error) {
+                                while (--i >= 0)
+                                        sysfs_remove_group(&drv->kobj,
+                                                           groups[i]);
+                                break;
+                        }
+                }
+        }
+        return error;
+}
+
+static void driver_remove_groups(struct device_driver *drv,
+                                 struct attribute_group **groups)
+{
+        int i;
+
+        if (groups)
+                for (i = 0; groups[i]; i++)
+                        sysfs_remove_group(&drv->kobj, groups[i]);
+}
+
+
 /**
  *      driver_register - register driver with bus
  *      @drv:   driver to register
@@ -152,13 +183,21 @@ void put_driver(struct device_driver * drv)
  */
 int driver_register(struct device_driver * drv)
 {
+        int ret;
+
         if ((drv->bus->probe && drv->probe) ||
             (drv->bus->remove && drv->remove) ||
             (drv->bus->shutdown && drv->shutdown)) {
                 printk(KERN_WARNING "Driver '%s' needs updating - please use bus_type methods\n", drv->name);
         }
         klist_init(&drv->klist_devices, NULL, NULL);
-        return bus_add_driver(drv);
+        ret = bus_add_driver(drv);
+        if (ret)
+                return ret;
+        ret = driver_add_groups(drv, drv->groups);
+        if (ret)
+                bus_remove_driver(drv);
+        return ret;
 }
 
 /**
@@ -170,6 +209,7 @@ int driver_register(struct device_driver * drv)
 
 void driver_unregister(struct device_driver * drv)
 {
+        driver_remove_groups(drv, drv->groups);
         bus_remove_driver(drv);
 }
 
diff --git a/include/linux/device.h b/include/linux/device.h
index 3f24bf46d298..d974dda4aa51 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -129,6 +129,7 @@ struct device_driver {
         void    (*shutdown)     (struct device * dev);
         int     (*suspend)      (struct device * dev, pm_message_t state);
         int     (*resume)       (struct device * dev);
+        struct attribute_group **groups;
 };