[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);
 }

include/asm-s390/ccwdev.h

@@ -67,36 +67,53 @@ ccw_device_id_match(const struct ccw_device_id *array,
 	return NULL;
 }
 
-/* The struct ccw device is our replacement for the globally accessible
- * ioinfo array. ioinfo will mutate into a subchannel device later.
+/**
+ * struct ccw_device - channel attached device
+ * @ccwlock: pointer to device lock
+ * @id: id of this device
+ * @drv: ccw driver for this device
+ * @dev: embedded device structure
+ * @online: online status of device
+ * @handler: interrupt handler
  *
- * Reference: Documentation/s390/driver-model.txt */
+ * @handler is a member of the device rather than the driver since a driver
+ * can have different interrupt handlers for different ccw devices
+ * (multi-subchannel drivers).
+ */
 struct ccw_device {
 	spinlock_t *ccwlock;
+/* private: */
 	struct ccw_device_private *private;	/* cio private information */
-	struct ccw_device_id id;	/* id of this device, driver_info is
-					   set by ccw_find_driver */
-	struct ccw_driver *drv;		/* */
-	struct device dev;		/* */
+/* public: */
+	struct ccw_device_id id;
+	struct ccw_driver *drv;
+	struct device dev;
 	int online;
-	/* This is sick, but a driver can have different interrupt handlers 
-	   for different ccw_devices (multi-subchannel drivers)... */
 	void (*handler) (struct ccw_device *, unsigned long, struct irb *);
 };
 
 
-/* Each ccw driver registers with the ccw root bus */
+/**
+ * struct ccw driver - device driver for channel attached devices
+ * @owner: owning module
+ * @ids: ids supported by this driver
+ * @probe: function called on probe
+ * @remove: function called on remove
+ * @set_online: called when setting device online
+ * @set_offline: called when setting device offline
+ * @notify: notify driver of device state changes
+ * @driver: embedded device driver structure
+ * @name: device driver name
+ */
 struct ccw_driver {
-	struct module *owner;		/* for automatic MOD_INC_USE_COUNT   */
-	struct ccw_device_id *ids;	/* probe driver with these devs      */
-	int (*probe) (struct ccw_device *); /* ask driver to probe dev 	     */
+	struct module *owner;
+	struct ccw_device_id *ids;
+	int (*probe) (struct ccw_device *);
 	void (*remove) (struct ccw_device *);
-					/* device is no longer available     */
 	int (*set_online) (struct ccw_device *);
 	int (*set_offline) (struct ccw_device *);
 	int (*notify) (struct ccw_device *, int);
-	struct device_driver driver;	/* higher level structure, don't init
-					   this from your driver	     */
+	struct device_driver driver;
 	char *name;
 };
 
@@ -124,36 +141,10 @@ extern void ccw_device_clear_options(struct ccw_device *, unsigned long);
 /* Allow forced onlining of boxed devices. */
 #define CCWDEV_ALLOW_FORCE              0x0008
 
-/*
- * ccw_device_start()
- *
- *  Start a S/390 channel program. When the interrupt arrives, the
- *  IRQ handler is called, either immediately, delayed (dev-end missing,
- *  or sense required) or never (no IRQ handler registered).
- *  Depending on the action taken, ccw_device_start() returns:  
- *                           0	     - Success
- *			     -EBUSY  - Device busy, or status pending
- *			     -ENODEV - Device not operational
- *                           -EINVAL - Device invalid for operation
- */
 extern int ccw_device_start(struct ccw_device *, struct ccw1 *,
 			    unsigned long, __u8, unsigned long);
-/*
- * ccw_device_start_timeout()
- *
- * This function notifies the device driver if the channel program has not
- * completed during the specified time. If a timeout occurs, the channel
- * program is terminated via xsch(), hsch() or csch().
- */
 extern int ccw_device_start_timeout(struct ccw_device *, struct ccw1 *,
 				    unsigned long, __u8, unsigned long, int);
-/*
- * ccw_device_start_key()
- * ccw_device_start_key_timeout()
- *
- * Same as ccw_device_start() and ccw_device_start_timeout(), except a
- * storage key != default key can be provided for the I/O.
- */
 extern int ccw_device_start_key(struct ccw_device *, struct ccw1 *,
 				unsigned long, __u8, __u8, unsigned long);
 extern int ccw_device_start_timeout_key(struct ccw_device *, struct ccw1 *,

include/asm-s390/ccwgroup.h

@@ -4,19 +4,41 @@
 struct ccw_device;
 struct ccw_driver;
 
+/**
+ * struct ccwgroup_device - ccw group device
+ * @creator_id: unique number of the driver
+ * @state: online/offline state
+ * @count: number of attached slave devices
+ * @dev: embedded device structure
+ * @cdev: variable number of slave devices, allocated as needed
+ */
 struct ccwgroup_device {
-	unsigned long creator_id;	/* unique number of the driver */
+	unsigned long creator_id;
 	enum {
 		CCWGROUP_OFFLINE,
 		CCWGROUP_ONLINE,
 	} state;
+/* private: */
 	atomic_t onoff;
 	struct mutex reg_mutex;
-	unsigned int count;		/* number of attached slave devices */
-	struct device	dev;		/* master device		    */
-	struct ccw_device *cdev[0];	/* variable number, allocate as needed */
+/* public: */
+	unsigned int count;
+	struct device	dev;
+	struct ccw_device *cdev[0];
 };
 
+/**
+ * struct ccwgroup_driver - driver for ccw group devices
+ * @owner: driver owner
+ * @name: driver name
+ * @max_slaves: maximum number of slave devices
+ * @driver_id: unique id
+ * @probe: function called on probe
+ * @remove: function called on remove
+ * @set_online: function called when device is set online
+ * @set_offline: function called when device is set offline
+ * @driver: embedded driver structure
+ */
 struct ccwgroup_driver {
 	struct module *owner;
 	char *name;
@@ -28,7 +50,7 @@ struct ccwgroup_driver {
 	int (*set_online) (struct ccwgroup_device *);
 	int (*set_offline) (struct ccwgroup_device *);
 
-	struct device_driver driver;		/* this driver */
+	struct device_driver driver;
 };
 
 extern int  ccwgroup_driver_register   (struct ccwgroup_driver *cdriver);