ipack: split ipack_device_register() in several functions

One function is ipack_device_init(). If it fails, the caller should execute
ipack_put_device().

The second function is ipack_device_add that only adds the device. If
it fails, the caller should execute ipack_put_device().

Then the device is removed with refcount = 0, as device_register() kernel
documentation says.

ipack_device_del() is added to remove the device.
Signed-off-by: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/ipack/carriers/tpci200.c

@@ -480,6 +480,7 @@ static void tpci200_release_device(struct ipack_device *dev)
 
 static int tpci200_create_device(struct tpci200_board *tpci200, int i)
 {
+	int ret;
 	enum ipack_space space;
 	struct ipack_device *dev =
 		kzalloc(sizeof(struct ipack_device), GFP_KERNEL);
@@ -495,7 +496,18 @@ static int tpci200_create_device(struct tpci200_board *tpci200, int i)
 			+ tpci200_space_interval[space] * i;
 		dev->region[space].size = tpci200_space_size[space];
 	}
-	return ipack_device_register(dev);
+
+	ret = ipack_device_init(dev);
+	if (ret < 0) {
+		ipack_put_device(dev);
+		return ret;
+	}
+
+	ret = ipack_device_add(dev);
+	if (ret < 0)
+		ipack_put_device(dev);
+
+	return ret;
 }
 
 static int tpci200_pci_probe(struct pci_dev *pdev,

drivers/ipack/ipack.c

@@ -227,7 +227,7 @@ static int ipack_unregister_bus_member(struct device *dev, void *data)
 	struct ipack_bus_device *bus = data;
 
 	if (idev->bus == bus)
-		ipack_device_unregister(idev);
+		ipack_device_del(idev);
 
 	return 1;
 }
@@ -419,7 +419,7 @@ static int ipack_device_read_id(struct ipack_device *dev)
 	return ret;
 }
 
-int ipack_device_register(struct ipack_device *dev)
+int ipack_device_init(struct ipack_device *dev)
 {
 	int ret;
 
@@ -428,6 +428,7 @@ int ipack_device_register(struct ipack_device *dev)
 	dev->dev.parent = dev->bus->parent;
 	dev_set_name(&dev->dev,
 		     "ipack-dev.%u.%u", dev->bus->bus_nr, dev->slot);
+	device_initialize(&dev->dev);
 
 	if (dev->bus->ops->set_clockrate(dev, 8))
 		dev_warn(&dev->dev, "failed to switch to 8 MHz operation for reading of device ID.\n");
@@ -447,19 +448,22 @@ int ipack_device_register(struct ipack_device *dev)
 			dev_err(&dev->dev, "failed to switch to 32 MHz operation.\n");
 	}
 
-	ret = device_register(&dev->dev);
-	if (ret < 0)
-		kfree(dev->id);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ipack_device_init);
 
-	return ret;
+int ipack_device_add(struct ipack_device *dev)
+{
+	return device_add(&dev->dev);
 }
-EXPORT_SYMBOL_GPL(ipack_device_register);
+EXPORT_SYMBOL_GPL(ipack_device_add);
 
-void ipack_device_unregister(struct ipack_device *dev)
+void ipack_device_del(struct ipack_device *dev)
 {
-	device_unregister(&dev->dev);
+	device_del(&dev->dev);
+	ipack_put_device(dev);
 }
-EXPORT_SYMBOL_GPL(ipack_device_unregister);
+EXPORT_SYMBOL_GPL(ipack_device_del);
 
 void ipack_get_device(struct ipack_device *dev)
 {

include/linux/ipack.h

@@ -207,19 +207,38 @@ int ipack_driver_register(struct ipack_driver *edrv, struct module *owner,
 void ipack_driver_unregister(struct ipack_driver *edrv);
 
 /**
- *	ipack_device_register -- register an IPack device with the kernel
- *	@dev: the new device to register.
+ *	ipack_device_init -- initialize an IPack device
+ * @dev: the new device to initialize.
  *
- *	Register a new IPack device ("module" in IndustryPack jargon). The call
- *	is done by the carrier driver.  The carrier should populate the fields
- *	bus and slot as well as the region array of @dev prior to calling this
- *	function.  The rest of the fields will be allocated and populated
- *	during registration.
+ * Initialize a new IPack device ("module" in IndustryPack jargon). The call
+ * is done by the carrier driver.  The carrier should populate the fields
+ * bus and slot as well as the region array of @dev prior to calling this
+ * function.  The rest of the fields will be allocated and populated
+ * during initalization.
  *
- *	Return zero on success or error code on failure.
+ * Return zero on success or error code on failure.
+ *
+ * NOTE: _Never_ directly free @dev after calling this function, even
+ * if it returned an error! Always use ipack_put_device() to give up the
+ * reference initialized in this function instead.
+ */
+int ipack_device_init(struct ipack_device *dev);
+
+/**
+ *	ipack_device_add -- Add an IPack device
+ * @dev: the new device to add.
+ *
+ * Add a new IPack device. The call is done by the carrier driver
+ * after calling ipack_device_init().
+ *
+ * Return zero on success or error code on failure.
+ *
+ * NOTE: _Never_ directly free @dev after calling this function, even
+ * if it returned an error! Always use ipack_put_device() to give up the
+ * reference initialized in this function instead.
  */
-int ipack_device_register(struct ipack_device *dev);
-void ipack_device_unregister(struct ipack_device *dev);
+int ipack_device_add(struct ipack_device *dev);
+void ipack_device_del(struct ipack_device *dev);
 
 void ipack_get_device(struct ipack_device *dev);
 void ipack_put_device(struct ipack_device *dev);