[S390] cio: Add docbook comments.

Comment a bunch of function in docbook style and convert existing
comments on structures to docbook.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

drivers/s390/cio/ccwgroup.c

@@ -152,16 +152,24 @@ __ccwgroup_create_symlinks(struct ccwgroup_device *gdev)
 	return 0;
 }
 
-/*
- * try to add a new ccwgroup device for one driver
- * argc and argv[] are a list of bus_id's of devices
- * belonging to the driver.
+/**
+ * ccwgroup_create() - 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
+ * @argc: number of slave devices
+ * @argv: 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 @argv[] and must all
+ * belong to @cdrv.
+ * Returns:
+ *  %0 on success and an error code on failure.
+ * Context:
+ *  non-atomic
  */
-int
-ccwgroup_create(struct device *root,
-		unsigned int creator_id,
-		struct ccw_driver *cdrv,
-		int argc, char *argv[])
+int ccwgroup_create(struct device *root, unsigned int creator_id,
+		    struct ccw_driver *cdrv, int argc, char *argv[])
 {
 	struct ccwgroup_device *gdev;
 	int i;
@@ -390,8 +398,13 @@ static struct bus_type ccwgroup_bus_type = {
 	.remove = ccwgroup_remove,
 };
 
-int
-ccwgroup_driver_register (struct ccwgroup_driver *cdriver)
+/**
+ * ccwgroup_driver_register() - register a ccw group driver
+ * @cdriver: driver to be registered
+ *
+ * This function is mainly a wrapper around driver_register().
+ */
+int ccwgroup_driver_register(struct ccwgroup_driver *cdriver)
 {
 	/* register our new driver with the core */
 	cdriver->driver.bus = &ccwgroup_bus_type;
@@ -406,8 +419,13 @@ __ccwgroup_match_all(struct device *dev, void *data)
 	return 1;
 }
 
-void
-ccwgroup_driver_unregister (struct ccwgroup_driver *cdriver)
+/**
+ * ccwgroup_driver_unregister() - deregister a ccw group driver
+ * @cdriver: driver to be deregistered
+ *
+ * This function is mainly a wrapper around driver_unregister().
+ */
+void ccwgroup_driver_unregister(struct ccwgroup_driver *cdriver)
 {
 	struct device *dev;
 
@@ -427,8 +445,16 @@ ccwgroup_driver_unregister (struct ccwgroup_driver *cdriver)
 	driver_unregister(&cdriver->driver);
 }
 
-int
-ccwgroup_probe_ccwdev(struct ccw_device *cdev)
+/**
+ * ccwgroup_probe_ccwdev() - probe function for slave devices
+ * @cdev: ccw device to be probed
+ *
+ * This is a dummy probe function for ccw devices that are slave devices in
+ * a ccw group device.
+ * Returns:
+ *  always %0
+ */
+int ccwgroup_probe_ccwdev(struct ccw_device *cdev)
 {
 	return 0;
 }
@@ -452,8 +478,15 @@ __ccwgroup_get_gdev_by_cdev(struct ccw_device *cdev)
 	return NULL;
 }
 
-void
-ccwgroup_remove_ccwdev(struct ccw_device *cdev)
+/**
+ * ccwgroup_remove_ccwdev() - remove function for slave devices
+ * @cdev: ccw device to be removed
+ *
+ * This is a remove function for ccw devices that are slave devices in a ccw
+ * group device. It sets the ccw device offline and also deregisters the
+ * embedding ccw group device.
+ */
+void ccwgroup_remove_ccwdev(struct ccw_device *cdev)
 {
 	struct ccwgroup_device *gdev;
 

drivers/s390/cio/device.c

@@ -357,8 +357,18 @@ ccw_device_remove_disconnected(struct ccw_device *cdev)
 			      cdev->private->dev_id.devno);
 }
 
-int
-ccw_device_set_offline(struct ccw_device *cdev)
+/**
+ * ccw_device_set_offline() - disable a ccw device for I/O
+ * @cdev: target ccw device
+ *
+ * This function calls the driver's set_offline() function for @cdev, if
+ * given, and then disables @cdev.
+ * Returns:
+ *   %0 on success and a negative error value on failure.
+ * Context:
+ *  enabled, ccw device lock not held
+ */
+int ccw_device_set_offline(struct ccw_device *cdev)
 {
 	int ret;
 
@@ -396,8 +406,19 @@ ccw_device_set_offline(struct ccw_device *cdev)
  	return ret;
 }
 
-int
-ccw_device_set_online(struct ccw_device *cdev)
+/**
+ * ccw_device_set_online() - enable a ccw device for I/O
+ * @cdev: target ccw device
+ *
+ * This function first enables @cdev and then calls the driver's set_online()
+ * function for @cdev, if given. If set_online() returns an error, @cdev is
+ * disabled again.
+ * Returns:
+ *   %0 on success and a negative error value on failure.
+ * Context:
+ *  enabled, ccw device lock not held
+ */
+int ccw_device_set_online(struct ccw_device *cdev)
 {
 	int ret;
 
@@ -1326,8 +1347,19 @@ __ccwdev_check_busid(struct device *dev, void *id)
 }
 
 
-struct ccw_device *
-get_ccwdev_by_busid(struct ccw_driver *cdrv, const char *bus_id)
+/**
+ * get_ccwdev_by_busid() - obtain device from a bus id
+ * @cdrv: driver the device is owned by
+ * @bus_id: bus id of the device to be searched
+ *
+ * This function searches all devices owned by @cdrv for a device with a bus
+ * id matching @bus_id.
+ * Returns:
+ *  If a match is found, its reference count of the found device is increased
+ *  and it is returned; else %NULL is returned.
+ */
+struct ccw_device *get_ccwdev_by_busid(struct ccw_driver *cdrv,
+				       const char *bus_id)
 {
 	struct device *dev;
 	struct device_driver *drv;
@@ -1409,8 +1441,15 @@ struct bus_type ccw_bus_type = {
 	.remove = ccw_device_remove,
 };
 
-int
-ccw_driver_register (struct ccw_driver *cdriver)
+/**
+ * ccw_driver_register() - register a ccw driver
+ * @cdriver: driver to be registered
+ *
+ * This function is mainly a wrapper around driver_register().
+ * Returns:
+ *   %0 on success and a negative error value on failure.
+ */
+int ccw_driver_register(struct ccw_driver *cdriver)
 {
 	struct device_driver *drv = &cdriver->driver;
 
@@ -1420,8 +1459,13 @@ ccw_driver_register (struct ccw_driver *cdriver)
 	return driver_register(drv);
 }
 
-void
-ccw_driver_unregister (struct ccw_driver *cdriver)
+/**
+ * ccw_driver_unregister() - deregister a ccw driver
+ * @cdriver: driver to be deregistered
+ *
+ * This function is mainly a wrapper around driver_unregister().
+ */
+void ccw_driver_unregister(struct ccw_driver *cdriver)
 {
 	driver_unregister(&cdriver->driver);
 }