s390/ccwgroup: introduce ccwgroup_create_dev

Add a new interface for drivers to create a group device. Via the old
interface ccwgroup_create_from_string we would create a virtual device
in a way that only the caller of this function would match and bind to.

Via the new ccwgroup_create_dev we stop playing games with the driver
core and directly set the driver of the new group device. For drivers
which have todo additional setup steps (like setting driver_data)
provide a new setup driver callback.

Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 45 insertions, 9 deletions

diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index 5f1dc6fb5708..0c7ed30ac87e 100644
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -1,7 +1,7 @@
 /*
  *  bus driver for ccwgroup
  *
- *  Copyright IBM Corp. 2002, 2009
+ *  Copyright IBM Corp. 2002, 2012
  *
  *  Author(s): Arnd Bergmann (arndb@de.ibm.com)
  *             Cornelia Huck (cornelia.huck@de.ibm.com)
@@ -291,14 +291,15 @@ static int __is_valid_bus_id(char bus_id[CCW_BUS_ID_SIZE])
 }
 
 /**
- * ccwgroup_create_from_string() - create and register a ccw group device
- * @root: parent device for the new device
+ * ccwgroup_create_dev() - create and register a ccw group device
+ * @parent: parent device for the new device
  * @creator_id: identifier of creating driver
  * @cdrv: ccw driver of slave devices
+ * @gdrv: driver for the new group device
  * @num_devices: number of slave devices
  * @buf: buffer containing comma separated bus ids of slave devices
  *
- * Create and register a new ccw group device as a child of @root. Slave
+ * Create and register a new ccw group device as a child of @parent. Slave
  * devices are obtained from the list of bus ids given in @buf and must all
  * belong to @cdrv.
  * Returns:
@@ -306,9 +307,9 @@ static int __is_valid_bus_id(char bus_id[CCW_BUS_ID_SIZE])
  * Context:
  *  non-atomic
  */
-int ccwgroup_create_from_string(struct device *root, unsigned int creator_id,
-                                struct ccw_driver *cdrv, int num_devices,
-                                const char *buf)
+int ccwgroup_create_dev(struct device *parent, unsigned int creator_id,
+                        struct ccw_driver *cdrv, struct ccwgroup_driver *gdrv,
+                        int num_devices, const char *buf)
 {
         struct ccwgroup_device *gdev;
         int rc, i;
@@ -323,10 +324,13 @@ int ccwgroup_create_from_string(struct device *root, unsigned int creator_id,
         atomic_set(&gdev->onoff, 0);
         mutex_init(&gdev->reg_mutex);
         mutex_lock(&gdev->reg_mutex);
-        gdev->creator_id = creator_id;
+        if (gdrv)
+                gdev->creator_id = gdrv->driver_id;
+        else
+                gdev->creator_id = creator_id;
         gdev->count = num_devices;
         gdev->dev.bus = &ccwgroup_bus_type;
-        gdev->dev.parent = root;
+        gdev->dev.parent = parent;
         gdev->dev.release = ccwgroup_release;
         device_initialize(&gdev->dev);
 
@@ -373,6 +377,13 @@ int ccwgroup_create_from_string(struct device *root, unsigned int creator_id,
 
         dev_set_name(&gdev->dev, "%s", dev_name(&gdev->cdev[0]->dev));
         gdev->dev.groups = ccwgroup_attr_groups;
+
+        if (gdrv) {
+                gdev->dev.driver = &gdrv->driver;
+                rc = gdrv->setup ? gdrv->setup(gdev) : 0;
+                if (rc)
+                        goto error;
+        }
         rc = device_add(&gdev->dev);
         if (rc)
                 goto error;
@@ -397,6 +408,31 @@ error:
         put_device(&gdev->dev);
         return rc;
 }
+EXPORT_SYMBOL(ccwgroup_create_dev);
+
+/**
+ * ccwgroup_create_from_string() - create and register a ccw group device
+ * @root: parent device for the new device
+ * @creator_id: identifier of creating driver
+ * @cdrv: ccw driver of slave devices
+ * @num_devices: number of slave devices
+ * @buf: buffer containing comma separated bus ids of slave devices
+ *
+ * Create and register a new ccw group device as a child of @root. Slave
+ * devices are obtained from the list of bus ids given in @buf and must all
+ * belong to @cdrv.
+ * Returns:
+ *  %0 on success and an error code on failure.
+ * Context:
+ *  non-atomic
+ */
+int ccwgroup_create_from_string(struct device *root, unsigned int creator_id,
+                                struct ccw_driver *cdrv, int num_devices,
+                                const char *buf)
+{
+        return ccwgroup_create_dev(root, creator_id, cdrv, NULL,
+                                   num_devices, buf);
+}
 EXPORT_SYMBOL(ccwgroup_create_from_string);
 
 static int ccwgroup_notifier(struct notifier_block *nb, unsigned long action,