[PATCH v10 4/7] nfc: pn533: Split pn533 init & nfc_register

[Lars Poeschel]

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 32ecc75ded72 ("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@xxxxxxxxxx>
Cc: Claudiu Beznea <Claudiu.Beznea@xxxxxxxxxxxxx>
Cc: Jakub Kicinski <jakub.kicinski@xxxxxxxxxxxxx>
Signed-off-by: Lars Poeschel <poeschel@xxxxxxxxxxx>
---
Changes in v10:
- Special case for initialisation for i2c: nfc_alloc_device and
  nfc_register_device is split with requesting irq inbetween.
- Fix style (parameters of pn53x_common_init on opening parenthesis)
- Rebased the patch series on net-next 'Commit 503a64635d5e ("Merge
  branch 'DPAA-Ethernet-changes'")'

Changes in v9:
- Rebased the patch series on v5.4-rc2

Changes in v7:
- Remove an unneeded rc variable initialization
- Corrected goto error to err_clean in pn533_usb_probe

Changes in v6:
- Rebased the patch series on v5.3-rc5

Changes in v5:
- This patch is new in v5

 drivers/nfc/pn533/i2c.c   | 27 +++++++++-----
 drivers/nfc/pn533/pn533.c | 76 ++++++++++++++++++++++-----------------
 drivers/nfc/pn533/pn533.h | 13 ++++---
 drivers/nfc/pn533/usb.c   | 16 +++++----
 4 files changed, 80 insertions(+), 52 deletions(-)

diff --git a/drivers/nfc/pn533/i2c.c b/drivers/nfc/pn533/i2c.c
index 1abd40398a5a..7507176cca0a 100644
--- a/drivers/nfc/pn533/i2c.c
+++ b/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;
 }
diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
index 64836c727aee..e185dc5f12b9 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/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@xxxxxxxxxxxxx>");
 MODULE_AUTHOR("Aloisio Almeida Jr <aloisio.almeida@xxxxxxxxxxxxx>");
diff --git a/drivers/nfc/pn533/pn533.h b/drivers/nfc/pn533/pn533.h
index 570ee0a3e832..984f79fef59e 100644
--- a/drivers/nfc/pn533/pn533.h
+++ b/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);
diff --git a/drivers/nfc/pn533/usb.c b/drivers/nfc/pn533/usb.c
index e897e4d768ef..4590fbf82dc2 100644
--- a/drivers/nfc/pn533/usb.c
+++ b/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);
 
-- 
2.23.0