nfc: pn533: Split pn533 init & nfc_register

There is a problem in the initialisation and setup of the pn533: It
registers with nfc too early. It could happen, that it finished
registering with nfc and someone starts using it. But setup of the pn533
is not yet finished. Bad or at least unintended things could happen.
So I split out nfc registering (and unregistering) to seperate functions
that have to be called late in probe then.
i2c requires a bit more love: i2c requests an irq in it's probe
function. 'Commit 32ecc75d ("NFC: pn533: change order operations in
dev registation")' shows, this can not happen too early. An irq can be
served before structs are fully initialized. The way chosen to prevent
this is to request the irq after nfc_alloc_device initialized the
structs, but before nfc_register_device. So there is now this
pn532_i2c_nfc_alloc function.

Cc: Johan Hovold <johan@kernel.org>
Cc: Claudiu Beznea <Claudiu.Beznea@microchip.com>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/nfc/pn533/i2c.c

@@ -193,12 +193,10 @@ static int pn533_i2c_probe(struct i2c_client *client,
 	phy->i2c_dev = client;
 	i2c_set_clientdata(client, phy);
 
-	priv = pn533_register_device(PN533_DEVICE_PN532,
-				     PN533_NO_TYPE_B_PROTOCOLS,
-				     PN533_PROTO_REQ_ACK_RESP,
-				     phy, &i2c_phy_ops, NULL,
-				     &phy->i2c_dev->dev,
-				     &client->dev);
+	priv = pn53x_common_init(PN533_DEVICE_PN532,
+				PN533_PROTO_REQ_ACK_RESP,
+				phy, &i2c_phy_ops, NULL,
+				&phy->i2c_dev->dev);
 
 	if (IS_ERR(priv)) {
 		r = PTR_ERR(priv);
@@ -206,6 +204,9 @@ static int pn533_i2c_probe(struct i2c_client *client,
 	}
 
 	phy->priv = priv;
+	r = pn532_i2c_nfc_alloc(priv, PN533_NO_TYPE_B_PROTOCOLS, &client->dev);
+	if (r)
+		goto nfc_alloc_err;
 
 	r = request_threaded_irq(client->irq, NULL, pn533_i2c_irq_thread_fn,
 				IRQF_TRIGGER_FALLING |
@@ -220,13 +221,20 @@ static int pn533_i2c_probe(struct i2c_client *client,
 	if (r)
 		goto fn_setup_err;
 
-	return 0;
+	r = nfc_register_device(priv->nfc_dev);
+	if (r)
+		goto fn_setup_err;
+
+	return r;
 
 fn_setup_err:
 	free_irq(client->irq, phy);
 
 irq_rqst_err:
-	pn533_unregister_device(phy->priv);
+	nfc_free_device(priv->nfc_dev);
+
+nfc_alloc_err:
+	pn53x_common_clean(phy->priv);
 
 	return r;
 }
@@ -239,7 +247,8 @@ static int pn533_i2c_remove(struct i2c_client *client)
 
 	free_irq(client->irq, phy);
 
-	pn533_unregister_device(phy->priv);
+	pn53x_unregister_nfc(phy->priv);
+	pn53x_common_clean(phy->priv);
 
 	return 0;
 }

drivers/nfc/pn533/pn533.c

@@ -2590,14 +2590,12 @@ int pn533_finalize_setup(struct pn533 *dev)
 }
 EXPORT_SYMBOL_GPL(pn533_finalize_setup);
 
-struct pn533 *pn533_register_device(u32 device_type,
-				u32 protocols,
+struct pn533 *pn53x_common_init(u32 device_type,
 				enum pn533_protocol_type protocol_type,
 				void *phy,
 				struct pn533_phy_ops *phy_ops,
 				struct pn533_frame_ops *fops,
-				struct device *dev,
-				struct device *parent)
+				struct device *dev)
 {
 	struct pn533 *priv;
 	int rc = -ENOMEM;
@@ -2638,43 +2636,18 @@ struct pn533 *pn533_register_device(u32 device_type,
 	skb_queue_head_init(&priv->fragment_skb);
 
 	INIT_LIST_HEAD(&priv->cmd_queue);
-
-	priv->nfc_dev = nfc_allocate_device(&pn533_nfc_ops, protocols,
-					   priv->ops->tx_header_len +
-					   PN533_CMD_DATAEXCH_HEAD_LEN,
-					   priv->ops->tx_tail_len);
-	if (!priv->nfc_dev) {
-		rc = -ENOMEM;
-		goto destroy_wq;
-	}
-
-	nfc_set_parent_dev(priv->nfc_dev, parent);
-	nfc_set_drvdata(priv->nfc_dev, priv);
-
-	rc = nfc_register_device(priv->nfc_dev);
-	if (rc)
-		goto free_nfc_dev;
-
 	return priv;
 
-free_nfc_dev:
-	nfc_free_device(priv->nfc_dev);
-
-destroy_wq:
-	destroy_workqueue(priv->wq);
 error:
 	kfree(priv);
 	return ERR_PTR(rc);
 }
-EXPORT_SYMBOL_GPL(pn533_register_device);
+EXPORT_SYMBOL_GPL(pn53x_common_init);
 
-void pn533_unregister_device(struct pn533 *priv)
+void pn53x_common_clean(struct pn533 *priv)
 {
 	struct pn533_cmd *cmd, *n;
 
-	nfc_unregister_device(priv->nfc_dev);
-	nfc_free_device(priv->nfc_dev);
-
 	flush_delayed_work(&priv->poll_work);
 	destroy_workqueue(priv->wq);
 
@@ -2689,8 +2662,47 @@ void pn533_unregister_device(struct pn533 *priv)
 
 	kfree(priv);
 }
-EXPORT_SYMBOL_GPL(pn533_unregister_device);
+EXPORT_SYMBOL_GPL(pn53x_common_clean);
+
+int pn532_i2c_nfc_alloc(struct pn533 *priv, u32 protocols,
+			struct device *parent)
+{
+	priv->nfc_dev = nfc_allocate_device(&pn533_nfc_ops, protocols,
+					   priv->ops->tx_header_len +
+					   PN533_CMD_DATAEXCH_HEAD_LEN,
+					   priv->ops->tx_tail_len);
+	if (!priv->nfc_dev)
+		return -ENOMEM;
+
+	nfc_set_parent_dev(priv->nfc_dev, parent);
+	nfc_set_drvdata(priv->nfc_dev, priv);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pn532_i2c_nfc_alloc);
+
+int pn53x_register_nfc(struct pn533 *priv, u32 protocols,
+			struct device *parent)
+{
+	int rc;
+
+	rc = pn532_i2c_nfc_alloc(priv, protocols, parent);
+	if (rc)
+		return rc;
+
+	rc = nfc_register_device(priv->nfc_dev);
+	if (rc)
+		nfc_free_device(priv->nfc_dev);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(pn53x_register_nfc);
 
+void pn53x_unregister_nfc(struct pn533 *priv)
+{
+	nfc_unregister_device(priv->nfc_dev);
+	nfc_free_device(priv->nfc_dev);
+}
+EXPORT_SYMBOL_GPL(pn53x_unregister_nfc);
 
 MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>");
 MODULE_AUTHOR("Aloisio Almeida Jr <aloisio.almeida@openbossa.org>");

drivers/nfc/pn533/pn533.h

@@ -219,18 +219,21 @@ struct pn533_phy_ops {
 };
 
 
-struct pn533 *pn533_register_device(u32 device_type,
-				u32 protocols,
+struct pn533 *pn53x_common_init(u32 device_type,
 				enum pn533_protocol_type protocol_type,
 				void *phy,
 				struct pn533_phy_ops *phy_ops,
 				struct pn533_frame_ops *fops,
-				struct device *dev,
-				struct device *parent);
+				struct device *dev);
 
 int pn533_finalize_setup(struct pn533 *dev);
-void pn533_unregister_device(struct pn533 *priv);
+void pn53x_common_clean(struct pn533 *priv);
 void pn533_recv_frame(struct pn533 *dev, struct sk_buff *skb, int status);
+int pn532_i2c_nfc_alloc(struct pn533 *priv, u32 protocols,
+			struct device *parent);
+int pn53x_register_nfc(struct pn533 *priv, u32 protocols,
+			struct device *parent);
+void pn53x_unregister_nfc(struct pn533 *priv);
 
 bool pn533_rx_frame_is_cmd_response(struct pn533 *dev, void *frame);
 bool pn533_rx_frame_is_ack(void *_frame);

drivers/nfc/pn533/usb.c

@@ -534,9 +534,9 @@ static int pn533_usb_probe(struct usb_interface *interface,
 		goto error;
 	}
 
-	priv = pn533_register_device(id->driver_info, protocols, protocol_type,
+	priv = pn53x_common_init(id->driver_info, protocol_type,
 					phy, &usb_phy_ops, fops,
-					&phy->udev->dev, &interface->dev);
+					&phy->udev->dev);
 
 	if (IS_ERR(priv)) {
 		rc = PTR_ERR(priv);
@@ -547,14 +547,17 @@ static int pn533_usb_probe(struct usb_interface *interface,
 
 	rc = pn533_finalize_setup(priv);
 	if (rc)
-		goto err_deregister;
+		goto err_clean;
 
 	usb_set_intfdata(interface, phy);
+	rc = pn53x_register_nfc(priv, protocols, &interface->dev);
+	if (rc)
+		goto err_clean;
 
 	return 0;
 
-err_deregister:
-	pn533_unregister_device(phy->priv);
+err_clean:
+	pn53x_common_clean(priv);
 error:
 	usb_kill_urb(phy->in_urb);
 	usb_kill_urb(phy->out_urb);
@@ -577,7 +580,8 @@ static void pn533_usb_disconnect(struct usb_interface *interface)
 	if (!phy)
 		return;
 
-	pn533_unregister_device(phy->priv);
+	pn53x_unregister_nfc(phy->priv);
+	pn53x_common_clean(phy->priv);
 
 	usb_set_intfdata(interface, NULL);