[PATCH v9 0/7] nfc: pn533: add uart phy driver

[PATCH v9 0/7] nfc: pn533: add uart phy driver

[Lars Poeschel]

The purpose of this patch series is to add a uart phy driver to the
pn533 nfc driver.
It first changes the dt strings and docs. The dt compatible strings
need to change, because I would add "pn532-uart" to the already
existing "pn533-i2c" one. These two are now unified into just
"pn532". Then the neccessary changes to the pn533 core driver are
made. Then the uart phy is added.
As the pn532 chip supports a autopoll, I wanted to use this instead
of the software poll loop in the pn533 core driver. It is added and
activated by the last to patches.
The way to add the autopoll later in seperate patches is chosen, to
show, that the uart phy driver can also work with the software poll
loop, if someone needs that for some reason.
This patchset is already rebased on Johans "NFC: pn533: fix
use-after-free and memleaks" patch
https://lore.kernel.org/netdev/20191007164059.5927-1-johan@kernel.org/
as they would conflict.
If for some reason Johans patch will not get merged, I can of course
provide the patchset without depending on this patch.

Cc: Lars Poeschel <poeschel@lemonage.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jilayne Lovejoy <opensource@jilayne.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Cc: Steve Winslow <swinslow@gmail.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Allison Randal <allison@lohutok.net>
Cc: Johan Hovold <johan@kernel.org>
Cc: Simon Horman <horms@verge.net.au>

Lars Poeschel (7):
  nfc: pn533: i2c: "pn532" as dt compatible string
  nfc: pn532: Add uart phy docs and rename it
  nfc: pn533: Add dev_up/dev_down hooks to phy_ops
  nfc: pn533: Split pn533 init & nfc_register
  nfc: pn533: add UART phy driver
  nfc: pn533: Add autopoll capability
  nfc: pn532_uart: Make use of pn532 autopoll

 .../net/nfc/{pn533-i2c.txt => pn532.txt}      |  25 +-
 drivers/nfc/pn533/Kconfig                     |  11 +
 drivers/nfc/pn533/Makefile                    |   2 +
 drivers/nfc/pn533/i2c.c                       |  22 +-
 drivers/nfc/pn533/pn533.c                     | 271 +++++++++++++--
 drivers/nfc/pn533/pn533.h                     |  38 +-
 drivers/nfc/pn533/uart.c                      | 324 ++++++++++++++++++
 drivers/nfc/pn533/usb.c                       |  12 +-
 8 files changed, 646 insertions(+), 59 deletions(-)
 rename Documentation/devicetree/bindings/net/nfc/{pn533-i2c.txt => pn532.txt} (42%)
 create mode 100644 drivers/nfc/pn533/uart.c

-- 
2.23.0

[PATCH v9 1/7] nfc: pn533: i2c: "pn532" as dt compatible string

[Lars Poeschel]

It is favourable to have one unified compatible string for devices that
have multiple interfaces. So this adds simply "pn532" as the devicetree
binding compatible string and makes a note that the old ones are
deprecated.

Cc: Johan Hovold <johan@kernel.org>
Cc: Simon Horman <horms@verge.net.au>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v9:
- Rebased the patch series on v5.4-rc2

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

Changes in v3:
- This patch is new in v3

 drivers/nfc/pn533/i2c.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/nfc/pn533/i2c.c b/drivers/nfc/pn533/i2c.c
index 1832cd921ea7..1abd40398a5a 100644
--- a/drivers/nfc/pn533/i2c.c
+++ b/drivers/nfc/pn533/i2c.c
@@ -245,6 +245,11 @@ static int pn533_i2c_remove(struct i2c_client *client)
 }
 
 static const struct of_device_id of_pn533_i2c_match[] = {
+	{ .compatible = "nxp,pn532", },
+	/*
+	 * NOTE: The use of the compatibles with the trailing "...-i2c" is
+	 * deprecated and will be removed.
+	 */
 	{ .compatible = "nxp,pn533-i2c", },
 	{ .compatible = "nxp,pn532-i2c", },
 	{},
-- 
2.23.0

[PATCH v9 2/7] nfc: pn532: Add uart phy docs and rename it

[Lars Poeschel]

This adds documentation about the uart phy to the pn532 binding doc. As
the filename "pn533-i2c.txt" is not appropriate any more, rename it to
the more general "pn532.txt".
This also documents the deprecation of the compatible strings ending
with "...-i2c".

Cc: Johan Hovold <johan@kernel.org>
Cc: Simon Horman <horms@verge.net.au>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v9:
- Rebased the patch series on v5.4-rc2
- Produce patch with -M4 to git format-patch to detect the rename
- Change DT node name from pn532@24 to nfc@24 in example

Changes in v8:
- Update existing binding doc instead of adding a new one:
  - Add uart phy example
  - Add general "pn532" compatible string
  - Deprecate "...-i2c" compatible strings
  - Rename file to a more general filename
- Intentionally drop Rob's Reviewed-By as I guess this rather big change
  requires a new review

Changes in v7:
- Accidentally lost Rob's Reviewed-By

Changes in v6:
- Rebased the patch series on v5.3-rc5
- Picked up Rob's Reviewed-By

Changes in v4:
- Add documentation about reg property in case of i2c

Changes in v3:
- seperate binding doc instead of entry in trivial-devices.txt

 .../net/nfc/{pn533-i2c.txt => pn532.txt}      | 25 ++++++++++++++++---
 1 file changed, 21 insertions(+), 4 deletions(-)
 rename Documentation/devicetree/bindings/net/nfc/{pn533-i2c.txt => pn532.txt} (42%)

diff --git a/Documentation/devicetree/bindings/net/nfc/pn533-i2c.txt b/Documentation/devicetree/bindings/net/nfc/pn532.txt
similarity index 42%
rename from Documentation/devicetree/bindings/net/nfc/pn533-i2c.txt
rename to Documentation/devicetree/bindings/net/nfc/pn532.txt
index 2efe3886b95b..a5507dc499bc 100644
--- a/Documentation/devicetree/bindings/net/nfc/pn533-i2c.txt
+++ b/Documentation/devicetree/bindings/net/nfc/pn532.txt
@@ -1,9 +1,16 @@
 * NXP Semiconductors PN532 NFC Controller
 
 Required properties:
-- compatible: Should be "nxp,pn532-i2c" or "nxp,pn533-i2c".
+- compatible: Should be
+    - "nxp,pn532" Place a node with this inside the devicetree node of the bus
+                  where the NFC chip is connected to.
+                  Currently the kernel has phy bindings for uart and i2c.
+    - "nxp,pn532-i2c" (DEPRECATED) only works for the i2c binding.
+    - "nxp,pn533-i2c" (DEPRECATED) only works for the i2c binding.
+
+Required properties if connected on i2c:
 - clock-frequency: I²C work frequency.
-- reg: address on the bus
+- reg: for the I²C bus address. This is fixed at 0x24 for the PN532.
 - interrupts: GPIO interrupt to which the chip is connected
 
 Optional SoC Specific Properties:
@@ -15,9 +22,9 @@ Example (for ARM-based BeagleBone with PN532 on I2C2):
 &i2c2 {
 
 
-	pn532: pn532@24 {
+	pn532: nfc@24 {
 
-		compatible = "nxp,pn532-i2c";
+		compatible = "nxp,pn532";
 
 		reg = <0x24>;
 		clock-frequency = <400000>;
@@ -27,3 +34,13 @@ Example (for ARM-based BeagleBone with PN532 on I2C2):
 
 	};
 };
+
+Example (for PN532 connected via uart):
+
+uart4: serial@49042000 {
+        compatible = "ti,omap3-uart";
+
+        pn532: nfc {
+                compatible = "nxp,pn532";
+        };
+};
-- 
2.23.0

[PATCH v9 3/7] nfc: pn533: Add dev_up/dev_down hooks to phy_ops

[Lars Poeschel]

This adds hooks for dev_up and dev_down to the phy_ops. They are
optional.
The idea is to inform the phy driver when the nfc chip is really going
to be used. When it is not used, the phy driver can suspend it's
interface to the nfc chip to save some power. The nfc chip is considered
not in use before dev_up and after dev_down.

Cc: Johan Hovold <johan@kernel.org>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v9:
- Rebased the patch series on v5.4-rc2

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

Changes in v5:
- (dev->phy_ops->dev_up) instead (dev->phy_ops)

Changes in v4:
- This patch is new in v4

 drivers/nfc/pn533/pn533.c | 12 +++++++++++-
 drivers/nfc/pn533/pn533.h |  9 +++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
index a172a32aa9d9..64836c727aee 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -2458,6 +2458,9 @@ static int pn533_dev_up(struct nfc_dev *nfc_dev)
 {
 	struct pn533 *dev = nfc_get_drvdata(nfc_dev);
 
+	if (dev->phy_ops->dev_up)
+		dev->phy_ops->dev_up(dev);
+
 	if (dev->device_type == PN533_DEVICE_PN532) {
 		int rc = pn532_sam_configuration(nfc_dev);
 
@@ -2470,7 +2473,14 @@ static int pn533_dev_up(struct nfc_dev *nfc_dev)
 
 static int pn533_dev_down(struct nfc_dev *nfc_dev)
 {
-	return pn533_rf_field(nfc_dev, 0);
+	struct pn533 *dev = nfc_get_drvdata(nfc_dev);
+	int ret;
+
+	ret = pn533_rf_field(nfc_dev, 0);
+	if (dev->phy_ops->dev_down && !ret)
+		dev->phy_ops->dev_down(dev);
+
+	return ret;
 }
 
 static struct nfc_ops pn533_nfc_ops = {
diff --git a/drivers/nfc/pn533/pn533.h b/drivers/nfc/pn533/pn533.h
index 8bf9d6ece0f5..570ee0a3e832 100644
--- a/drivers/nfc/pn533/pn533.h
+++ b/drivers/nfc/pn533/pn533.h
@@ -207,6 +207,15 @@ struct pn533_phy_ops {
 			  struct sk_buff *out);
 	int (*send_ack)(struct pn533 *dev, gfp_t flags);
 	void (*abort_cmd)(struct pn533 *priv, gfp_t flags);
+	/*
+	 * dev_up and dev_down are optional.
+	 * They are used to inform the phy layer that the nfc chip
+	 * is going to be really used very soon. The phy layer can then
+	 * bring up it's interface to the chip and have it suspended for power
+	 * saving reasons otherwise.
+	 */
+	void (*dev_up)(struct pn533 *priv);
+	void (*dev_down)(struct pn533 *priv);
 };
 
 
-- 
2.23.0

[PATCH v9 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.

Cc: Johan Hovold <johan@kernel.org>
Cc: Claudiu Beznea <Claudiu.Beznea@microchip.com>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v9:
- Rebased the patch series on v5.4-rc2
- This is already rebased with Johans "NFC: pn533: fix use-after-free
  and memleaks" patch applied

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   | 17 +++++-----
 drivers/nfc/pn533/pn533.c | 66 ++++++++++++++++++++-------------------
 drivers/nfc/pn533/pn533.h | 11 ++++---
 drivers/nfc/pn533/usb.c   | 12 ++++---
 4 files changed, 58 insertions(+), 48 deletions(-)

diff --git a/drivers/nfc/pn533/i2c.c b/drivers/nfc/pn533/i2c.c
index 1abd40398a5a..e9e5a1ec8857 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,
+	priv = pn53x_common_init(PN533_DEVICE_PN532,
 				     PN533_PROTO_REQ_ACK_RESP,
 				     phy, &i2c_phy_ops, NULL,
-				     &phy->i2c_dev->dev,
-				     &client->dev);
+				     &phy->i2c_dev->dev);
 
 	if (IS_ERR(priv)) {
 		r = PTR_ERR(priv);
@@ -220,13 +218,17 @@ static int pn533_i2c_probe(struct i2c_client *client,
 	if (r)
 		goto fn_setup_err;
 
-	return 0;
+	r = pn53x_register_nfc(priv, PN533_NO_TYPE_B_PROTOCOLS, &client->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);
+	pn53x_common_clean(phy->priv);
 
 	return r;
 }
@@ -239,7 +241,8 @@ 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..e5d5e4c83a04 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 +2662,37 @@ void pn533_unregister_device(struct pn533 *priv)
 
 	kfree(priv);
 }
-EXPORT_SYMBOL_GPL(pn533_unregister_device);
+EXPORT_SYMBOL_GPL(pn53x_common_clean);
+
+int pn53x_register_nfc(struct pn533 *priv, u32 protocols,
+			struct device *parent)
+{
+	int rc;
+
+	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);
+
+	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>");
diff --git a/drivers/nfc/pn533/pn533.h b/drivers/nfc/pn533/pn533.h
index 570ee0a3e832..510ddebbd896 100644
--- a/drivers/nfc/pn533/pn533.h
+++ b/drivers/nfc/pn533/pn533.h
@@ -219,18 +219,19 @@ 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 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..e60d330e64fb 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);
@@ -550,11 +550,14 @@ static int pn533_usb_probe(struct usb_interface *interface,
 		goto err_deregister;
 
 	usb_set_intfdata(interface, phy);
+	rc = pn53x_register_nfc(priv, protocols, &interface->dev);
+	if (rc)
+		goto err_deregister;
 
 	return 0;
 
 err_deregister:
-	pn533_unregister_device(phy->priv);
+	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

[PATCH v9 5/7] nfc: pn533: add UART phy driver

[Lars Poeschel]

This adds the UART phy interface for the pn533 driver.
The pn533 driver can be used through UART interface this way.
It is implemented as a serdev device.

Cc: Johan Hovold <johan@kernel.org>
Cc: Claudiu Beznea <Claudiu.Beznea@microchip.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v9:
- Rebased the patch series on v5.4-rc2

Changes in v8:
- Reverse christmas tree order for local variables in
  pn532_uart_send_ack and pn532_uart_rx_is_frame

Changes in v7:
- Add comment at send_wakeup variable to document a possible and
  harmless concurrency issue

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

Changes in v5:
- Use the splitted pn53x_common_init and pn53x_register_nfc
  and pn53x_common_clean and pn53x_unregister_nfc alike

Changes in v4:
- SPDX-License-Identifier: GPL-2.0+
- Source code comments above refering items
- Error check for serdev_device_write's
- Change if (xxx == NULL) to if (!xxx)
- Remove device name from a dev_err
- move pn533_register in _probe a bit towards the end of _probe
- make use of newly added dev_up / dev_down phy_ops
- control send_wakeup variable from dev_up / dev_down

Changes in v3:
- depend on SERIAL_DEV_BUS in Kconfig

Changes in v2:
- switched from tty line discipline to serdev, resulting in many
  simplifications
- SPDX License Identifier

 drivers/nfc/pn533/Kconfig  |  11 ++
 drivers/nfc/pn533/Makefile |   2 +
 drivers/nfc/pn533/pn533.h  |   8 +
 drivers/nfc/pn533/uart.c   | 324 +++++++++++++++++++++++++++++++++++++
 4 files changed, 345 insertions(+)
 create mode 100644 drivers/nfc/pn533/uart.c

diff --git a/drivers/nfc/pn533/Kconfig b/drivers/nfc/pn533/Kconfig
index f6d6b345ba0d..7fe1bbe26568 100644
--- a/drivers/nfc/pn533/Kconfig
+++ b/drivers/nfc/pn533/Kconfig
@@ -26,3 +26,14 @@ config NFC_PN533_I2C
 
 	  If you choose to build a module, it'll be called pn533_i2c.
 	  Say N if unsure.
+
+config NFC_PN532_UART
+	tristate "NFC PN532 device support (UART)"
+	depends on SERIAL_DEV_BUS
+	select NFC_PN533
+	---help---
+	  This module adds support for the NXP pn532 UART interface.
+	  Select this if your platform is using the UART bus.
+
+	  If you choose to build a module, it'll be called pn532_uart.
+	  Say N if unsure.
diff --git a/drivers/nfc/pn533/Makefile b/drivers/nfc/pn533/Makefile
index 43c25b4f9466..b9648337576f 100644
--- a/drivers/nfc/pn533/Makefile
+++ b/drivers/nfc/pn533/Makefile
@@ -4,7 +4,9 @@
 #
 pn533_usb-objs  = usb.o
 pn533_i2c-objs  = i2c.o
+pn532_uart-objs  = uart.o
 
 obj-$(CONFIG_NFC_PN533)     += pn533.o
 obj-$(CONFIG_NFC_PN533_USB) += pn533_usb.o
 obj-$(CONFIG_NFC_PN533_I2C) += pn533_i2c.o
+obj-$(CONFIG_NFC_PN532_UART) += pn532_uart.o
diff --git a/drivers/nfc/pn533/pn533.h b/drivers/nfc/pn533/pn533.h
index 510ddebbd896..6541088fad73 100644
--- a/drivers/nfc/pn533/pn533.h
+++ b/drivers/nfc/pn533/pn533.h
@@ -43,6 +43,11 @@
 
 /* Preamble (1), SoPC (2), ACK Code (2), Postamble (1) */
 #define PN533_STD_FRAME_ACK_SIZE 6
+/*
+ * Preamble (1), SoPC (2), Packet Length (1), Packet Length Checksum (1),
+ * Specific Application Level Error Code (1) , Postamble (1)
+ */
+#define PN533_STD_ERROR_FRAME_SIZE 8
 #define PN533_STD_FRAME_CHECKSUM(f) (f->data[f->datalen])
 #define PN533_STD_FRAME_POSTAMBLE(f) (f->data[f->datalen + 1])
 /* Half start code (3), LEN (4) should be 0xffff for extended frame */
@@ -84,6 +89,9 @@
 #define PN533_CMD_MI_MASK 0x40
 #define PN533_CMD_RET_SUCCESS 0x00
 
+#define PN533_FRAME_DATALEN_ACK 0x00
+#define PN533_FRAME_DATALEN_ERROR 0x01
+#define PN533_FRAME_DATALEN_EXTENDED 0xFF
 
 enum  pn533_protocol_type {
 	PN533_PROTO_REQ_ACK_RESP = 0,
diff --git a/drivers/nfc/pn533/uart.c b/drivers/nfc/pn533/uart.c
new file mode 100644
index 000000000000..7f639051cdd0
--- /dev/null
+++ b/drivers/nfc/pn533/uart.c
@@ -0,0 +1,324 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for NXP PN532 NFC Chip - UART transport layer
+ *
+ * Copyright (C) 2018 Lemonage Software GmbH
+ * Author: Lars Pöschel <poeschel@lemonage.de>
+ * All rights reserved.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/nfc.h>
+#include <linux/netdevice.h>
+#include <linux/of.h>
+#include <linux/serdev.h>
+#include "pn533.h"
+
+#define PN532_UART_SKB_BUFF_LEN	(PN533_CMD_DATAEXCH_DATA_MAXLEN * 2)
+
+enum send_wakeup {
+	PN532_SEND_NO_WAKEUP = 0,
+	PN532_SEND_WAKEUP,
+	PN532_SEND_LAST_WAKEUP,
+};
+
+
+struct pn532_uart_phy {
+	struct serdev_device *serdev;
+	struct sk_buff *recv_skb;
+	struct pn533 *priv;
+	/*
+	 * send_wakeup variable is used to control if we need to send a wakeup
+	 * request to the pn532 chip prior to our actual command. There is a
+	 * little propability of a race condition. We decided to not mutex the
+	 * variable as the worst that could happen is, that we send a wakeup
+	 * to the chip that is already awake. This does not hurt. It is a
+	 * no-op to the chip.
+	 */
+	enum send_wakeup send_wakeup;
+	struct timer_list cmd_timeout;
+	struct sk_buff *cur_out_buf;
+};
+
+static int pn532_uart_send_frame(struct pn533 *dev,
+				struct sk_buff *out)
+{
+	/* wakeup sequence and dummy bytes for waiting time */
+	static const u8 wakeup[] = {
+		0x55, 0x55, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x00};
+	struct pn532_uart_phy *pn532 = dev->phy;
+	int err;
+
+	print_hex_dump_debug("PN532_uart TX: ", DUMP_PREFIX_NONE, 16, 1,
+			     out->data, out->len, false);
+
+	pn532->cur_out_buf = out;
+	if (pn532->send_wakeup) {
+		err= serdev_device_write(pn532->serdev,
+				wakeup, sizeof(wakeup),
+				MAX_SCHEDULE_TIMEOUT);
+		if (err < 0)
+			return err;
+	}
+
+	if (pn532->send_wakeup == PN532_SEND_LAST_WAKEUP) {
+		pn532->send_wakeup = PN532_SEND_NO_WAKEUP;
+	}
+
+	err = serdev_device_write(pn532->serdev, out->data, out->len,
+			MAX_SCHEDULE_TIMEOUT);
+	if (err < 0)
+		return err;
+
+	mod_timer(&pn532->cmd_timeout, HZ / 40 + jiffies);
+	return 0;
+}
+
+static int pn532_uart_send_ack(struct pn533 *dev, gfp_t flags)
+{
+	/* spec 7.1.1.3:  Preamble, SoPC (2), ACK Code (2), Postamble */
+	static const u8 ack[PN533_STD_FRAME_ACK_SIZE] = {
+			0x00, 0x00, 0xff, 0x00, 0xff, 0x00};
+	struct pn532_uart_phy *pn532 = dev->phy;
+	int err;
+
+	err = serdev_device_write(pn532->serdev, ack, sizeof(ack),
+			MAX_SCHEDULE_TIMEOUT);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+static void pn532_uart_abort_cmd(struct pn533 *dev, gfp_t flags)
+{
+	/* An ack will cancel the last issued command */
+	pn532_uart_send_ack(dev, flags);
+	/* schedule cmd_complete_work to finish current command execution */
+	pn533_recv_frame(dev, NULL, -ENOENT);
+}
+
+static void pn532_dev_up(struct pn533 *dev)
+{
+	struct pn532_uart_phy *pn532 = dev->phy;
+
+	serdev_device_open(pn532->serdev);
+	pn532->send_wakeup = PN532_SEND_LAST_WAKEUP;
+}
+
+static void pn532_dev_down(struct pn533 *dev)
+{
+	struct pn532_uart_phy *pn532 = dev->phy;
+
+	serdev_device_close(pn532->serdev);
+	pn532->send_wakeup = PN532_SEND_WAKEUP;
+}
+
+static struct pn533_phy_ops uart_phy_ops = {
+	.send_frame = pn532_uart_send_frame,
+	.send_ack = pn532_uart_send_ack,
+	.abort_cmd = pn532_uart_abort_cmd,
+	.dev_up = pn532_dev_up,
+	.dev_down = pn532_dev_down,
+};
+
+static void pn532_cmd_timeout(struct timer_list *t)
+{
+	struct pn532_uart_phy *dev = from_timer(dev, t, cmd_timeout);
+
+	pn532_uart_send_frame(dev->priv, dev->cur_out_buf);
+}
+
+/*
+ * scans the buffer if it contains a pn532 frame. It is not checked if the
+ * frame is really valid. This is later done with pn533_rx_frame_is_valid.
+ * This is useful for malformed or errornous transmitted frames. Adjusts the
+ * bufferposition where the frame starts, since pn533_recv_frame expects a
+ * well formed frame.
+ */
+static int pn532_uart_rx_is_frame(struct sk_buff *skb)
+{
+	struct pn533_std_frame *std;
+	struct pn533_ext_frame *ext;
+	u16 frame_len;
+	int i;
+
+	for (i = 0; i + PN533_STD_FRAME_ACK_SIZE <= skb->len; i++) {
+		std = (struct pn533_std_frame *)&skb->data[i];
+		/* search start code */
+		if (std->start_frame != cpu_to_be16(PN533_STD_FRAME_SOF))
+			continue;
+
+		/* frame type */
+		switch (std->datalen) {
+		case PN533_FRAME_DATALEN_ACK:
+			if (std->datalen_checksum == 0xff) {
+				skb_pull(skb, i);
+				return 1;
+			}
+
+			break;
+		case PN533_FRAME_DATALEN_ERROR:
+			if ((std->datalen_checksum == 0xff) &&
+					(skb->len >=
+					 PN533_STD_ERROR_FRAME_SIZE)) {
+				skb_pull(skb, i);
+				return 1;
+			}
+
+			break;
+		case PN533_FRAME_DATALEN_EXTENDED:
+			ext = (struct pn533_ext_frame *)&skb->data[i];
+			frame_len = ext->datalen;
+			if (skb->len >= frame_len +
+					sizeof(struct pn533_ext_frame) +
+					2 /* CKS + Postamble */) {
+				skb_pull(skb, i);
+				return 1;
+			}
+
+			break;
+		default: /* normal information frame */
+			frame_len = std->datalen;
+			if (skb->len >= frame_len +
+					sizeof(struct pn533_std_frame) +
+					2 /* CKS + Postamble */) {
+				skb_pull(skb, i);
+				return 1;
+			}
+
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static int pn532_receive_buf(struct serdev_device *serdev,
+		const unsigned char *data, size_t count)
+{
+	struct pn532_uart_phy *dev = serdev_device_get_drvdata(serdev);
+	size_t i;
+
+	del_timer(&dev->cmd_timeout);
+	for (i = 0; i < count; i++) {
+		skb_put_u8(dev->recv_skb, *data++);
+		if (!pn532_uart_rx_is_frame(dev->recv_skb))
+			continue;
+
+		pn533_recv_frame(dev->priv, dev->recv_skb, 0);
+		dev->recv_skb = alloc_skb(PN532_UART_SKB_BUFF_LEN, GFP_KERNEL);
+		if (!dev->recv_skb)
+			return 0;
+	}
+
+	return i;
+}
+
+static struct serdev_device_ops pn532_serdev_ops = {
+	.receive_buf = pn532_receive_buf,
+	.write_wakeup = serdev_device_write_wakeup,
+};
+
+static const struct of_device_id pn532_uart_of_match[] = {
+	{ .compatible = "nxp,pn532", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, pn532_uart_of_match);
+
+static int pn532_uart_probe(struct serdev_device *serdev)
+{
+	struct pn532_uart_phy *pn532;
+	struct pn533 *priv;
+	int err;
+
+	err = -ENOMEM;
+	pn532 = kzalloc(sizeof(*pn532), GFP_KERNEL);
+	if (!pn532)
+		goto err_exit;
+
+	pn532->recv_skb = alloc_skb(PN532_UART_SKB_BUFF_LEN, GFP_KERNEL);
+	if (!pn532->recv_skb)
+		goto err_free;
+
+	pn532->serdev = serdev;
+	serdev_device_set_drvdata(serdev, pn532);
+	serdev_device_set_client_ops(serdev, &pn532_serdev_ops);
+	err = serdev_device_open(serdev);
+	if (err) {
+		dev_err(&serdev->dev, "Unable to open device\n");
+		goto err_skb;
+	}
+
+	err = serdev_device_set_baudrate(serdev, 115200);
+	if (err != 115200) {
+		err = -EINVAL;
+		goto err_serdev;
+	}
+
+	serdev_device_set_flow_control(serdev, false);
+	pn532->send_wakeup = PN532_SEND_WAKEUP;
+	timer_setup(&pn532->cmd_timeout, pn532_cmd_timeout, 0);
+	priv = pn53x_common_init(PN533_DEVICE_PN532,
+				     PN533_PROTO_REQ_ACK_RESP,
+				     pn532, &uart_phy_ops, NULL,
+				     &pn532->serdev->dev);
+	if (IS_ERR(priv)) {
+		err = PTR_ERR(priv);
+		goto err_serdev;
+	}
+
+	pn532->priv = priv;
+	err = pn533_finalize_setup(pn532->priv);
+	if (err)
+		goto err_clean;
+
+	serdev_device_close(serdev);
+	err = pn53x_register_nfc(priv, PN533_NO_TYPE_B_PROTOCOLS, &serdev->dev);
+	if (err) {
+		pn53x_common_clean(pn532->priv);
+		goto err_skb;
+	}
+
+	return err;
+
+err_clean:
+	pn53x_common_clean(pn532->priv);
+err_serdev:
+	serdev_device_close(serdev);
+err_skb:
+	kfree_skb(pn532->recv_skb);
+err_free:
+	kfree(pn532);
+err_exit:
+	return err;
+}
+
+static void pn532_uart_remove(struct serdev_device *serdev)
+{
+	struct pn532_uart_phy *pn532 = serdev_device_get_drvdata(serdev);
+
+	pn53x_unregister_nfc(pn532->priv);
+	serdev_device_close(serdev);
+	pn53x_common_clean(pn532->priv);
+	kfree_skb(pn532->recv_skb);
+	kfree(pn532);
+}
+
+static struct serdev_device_driver pn532_uart_driver = {
+	.probe = pn532_uart_probe,
+	.remove = pn532_uart_remove,
+	.driver = {
+		.name = "pn532_uart",
+		.of_match_table = of_match_ptr(pn532_uart_of_match),
+	},
+};
+
+module_serdev_device_driver(pn532_uart_driver);
+
+MODULE_AUTHOR("Lars Pöschel <poeschel@lemonage.de>");
+MODULE_DESCRIPTION("PN532 UART driver");
+MODULE_LICENSE("GPL");
-- 
2.23.0

[PATCH v9 6/7] nfc: pn533: Add autopoll capability

[Lars Poeschel]

pn532 devices support an autopoll command, that lets the chip
automatically poll for selected nfc technologies instead of manually
looping through every single nfc technology the user is interested in.
This is faster and less cpu and bus intensive than manually polling.
This adds this autopoll capability to the pn533 driver.

Cc: Johan Hovold <johan@kernel.org>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v9:
- Rebased the patch series on v5.4-rc2

Changes in v8:
- Reverse christmas tree order for local variables in
  pn533_autopoll_complete and pn533_start_poll

Changes in v7:
- Remove __packed attribute at struct pn532_autopoll_resp
- Add missing '\n' at the end of dev_dbg and nfc_err strings

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

 drivers/nfc/pn533/pn533.c | 193 +++++++++++++++++++++++++++++++++++++-
 drivers/nfc/pn533/pn533.h |  10 +-
 2 files changed, 197 insertions(+), 6 deletions(-)

diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c
index e5d5e4c83a04..044b52d036e3 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -185,6 +185,32 @@ struct pn533_cmd_jump_dep_response {
 	u8 gt[];
 } __packed;
 
+struct pn532_autopoll_resp {
+	u8 type;
+	u8 ln;
+	u8 tg;
+	u8 tgdata[];
+};
+
+/* PN532_CMD_IN_AUTOPOLL */
+#define PN532_AUTOPOLL_POLLNR_INFINITE	0xff
+#define PN532_AUTOPOLL_PERIOD		0x03 /* in units of 150 ms */
+
+#define PN532_AUTOPOLL_TYPE_GENERIC_106		0x00
+#define PN532_AUTOPOLL_TYPE_GENERIC_212		0x01
+#define PN532_AUTOPOLL_TYPE_GENERIC_424		0x02
+#define PN532_AUTOPOLL_TYPE_JEWEL		0x04
+#define PN532_AUTOPOLL_TYPE_MIFARE		0x10
+#define PN532_AUTOPOLL_TYPE_FELICA212		0x11
+#define PN532_AUTOPOLL_TYPE_FELICA424		0x12
+#define PN532_AUTOPOLL_TYPE_ISOA		0x20
+#define PN532_AUTOPOLL_TYPE_ISOB		0x23
+#define PN532_AUTOPOLL_TYPE_DEP_PASSIVE_106	0x40
+#define PN532_AUTOPOLL_TYPE_DEP_PASSIVE_212	0x41
+#define PN532_AUTOPOLL_TYPE_DEP_PASSIVE_424	0x42
+#define PN532_AUTOPOLL_TYPE_DEP_ACTIVE_106	0x80
+#define PN532_AUTOPOLL_TYPE_DEP_ACTIVE_212	0x81
+#define PN532_AUTOPOLL_TYPE_DEP_ACTIVE_424	0x82
 
 /* PN533_TG_INIT_AS_TARGET */
 #define PN533_INIT_TARGET_PASSIVE 0x1
@@ -1389,6 +1415,101 @@ static int pn533_poll_dep(struct nfc_dev *nfc_dev)
 	return rc;
 }
 
+static int pn533_autopoll_complete(struct pn533 *dev, void *arg,
+			       struct sk_buff *resp)
+{
+	struct pn532_autopoll_resp *apr;
+	struct nfc_target nfc_tgt;
+	u8 nbtg;
+	int rc;
+
+	if (IS_ERR(resp)) {
+		rc = PTR_ERR(resp);
+
+		nfc_err(dev->dev, "%s  autopoll complete error %d\n",
+			__func__, rc);
+
+		if (rc == -ENOENT) {
+			if (dev->poll_mod_count != 0)
+				return rc;
+			goto stop_poll;
+		} else if (rc < 0) {
+			nfc_err(dev->dev,
+				"Error %d when running autopoll\n", rc);
+			goto stop_poll;
+		}
+	}
+
+	nbtg = resp->data[0];
+	if ((nbtg > 2) || (nbtg <= 0))
+		return -EAGAIN;
+
+	apr = (struct pn532_autopoll_resp *)&resp->data[1];
+	while (nbtg--) {
+		memset(&nfc_tgt, 0, sizeof(struct nfc_target));
+		switch (apr->type) {
+		case PN532_AUTOPOLL_TYPE_ISOA:
+			dev_dbg(dev->dev, "ISOA\n");
+			rc = pn533_target_found_type_a(&nfc_tgt, apr->tgdata,
+						       apr->ln - 1);
+			break;
+		case PN532_AUTOPOLL_TYPE_FELICA212:
+		case PN532_AUTOPOLL_TYPE_FELICA424:
+			dev_dbg(dev->dev, "FELICA\n");
+			rc = pn533_target_found_felica(&nfc_tgt, apr->tgdata,
+						       apr->ln - 1);
+			break;
+		case PN532_AUTOPOLL_TYPE_JEWEL:
+			dev_dbg(dev->dev, "JEWEL\n");
+			rc = pn533_target_found_jewel(&nfc_tgt, apr->tgdata,
+						      apr->ln - 1);
+			break;
+		case PN532_AUTOPOLL_TYPE_ISOB:
+			dev_dbg(dev->dev, "ISOB\n");
+			rc = pn533_target_found_type_b(&nfc_tgt, apr->tgdata,
+						       apr->ln - 1);
+			break;
+		case PN532_AUTOPOLL_TYPE_MIFARE:
+			dev_dbg(dev->dev, "Mifare\n");
+			rc = pn533_target_found_type_a(&nfc_tgt, apr->tgdata,
+						       apr->ln - 1);
+			break;
+		default:
+			nfc_err(dev->dev,
+				    "Unknown current poll modulation\n");
+			rc = -EPROTO;
+		}
+
+		if (rc)
+			goto done;
+
+		if (!(nfc_tgt.supported_protocols & dev->poll_protocols)) {
+			nfc_err(dev->dev,
+				    "The Tg found doesn't have the desired protocol\n");
+			rc = -EAGAIN;
+			goto done;
+		}
+
+		dev->tgt_available_prots = nfc_tgt.supported_protocols;
+		apr = (struct pn532_autopoll_resp *)
+			(apr->tgdata + (apr->ln - 1));
+	}
+
+	pn533_poll_reset_mod_list(dev);
+	nfc_targets_found(dev->nfc_dev, &nfc_tgt, 1);
+
+done:
+	dev_kfree_skb(resp);
+	return rc;
+
+stop_poll:
+	nfc_err(dev->dev, "autopoll operation has been stopped\n");
+
+	pn533_poll_reset_mod_list(dev);
+	dev->poll_protocols = 0;
+	return rc;
+}
+
 static int pn533_poll_complete(struct pn533 *dev, void *arg,
 			       struct sk_buff *resp)
 {
@@ -1532,6 +1653,7 @@ static int pn533_start_poll(struct nfc_dev *nfc_dev,
 {
 	struct pn533 *dev = nfc_get_drvdata(nfc_dev);
 	struct pn533_poll_modulations *cur_mod;
+	struct sk_buff *skb;
 	u8 rand_mod;
 	int rc;
 
@@ -1557,9 +1679,73 @@ static int pn533_start_poll(struct nfc_dev *nfc_dev,
 			tm_protocols = 0;
 	}
 
-	pn533_poll_create_mod_list(dev, im_protocols, tm_protocols);
 	dev->poll_protocols = im_protocols;
 	dev->listen_protocols = tm_protocols;
+	if (dev->device_type == PN533_DEVICE_PN532_AUTOPOLL) {
+		skb = pn533_alloc_skb(dev, 4 + 6);
+		if (!skb)
+			return -ENOMEM;
+
+		*((u8 *)skb_put(skb, sizeof(u8))) =
+			PN532_AUTOPOLL_POLLNR_INFINITE;
+		*((u8 *)skb_put(skb, sizeof(u8))) = PN532_AUTOPOLL_PERIOD;
+
+		if ((im_protocols & NFC_PROTO_MIFARE_MASK) &&
+				(im_protocols & NFC_PROTO_ISO14443_MASK) &&
+				(im_protocols & NFC_PROTO_NFC_DEP_MASK))
+			*((u8 *)skb_put(skb, sizeof(u8))) =
+				PN532_AUTOPOLL_TYPE_GENERIC_106;
+		else {
+			if (im_protocols & NFC_PROTO_MIFARE_MASK)
+				*((u8 *)skb_put(skb, sizeof(u8))) =
+					PN532_AUTOPOLL_TYPE_MIFARE;
+
+			if (im_protocols & NFC_PROTO_ISO14443_MASK)
+				*((u8 *)skb_put(skb, sizeof(u8))) =
+					PN532_AUTOPOLL_TYPE_ISOA;
+
+			if (im_protocols & NFC_PROTO_NFC_DEP_MASK) {
+				*((u8 *)skb_put(skb, sizeof(u8))) =
+					PN532_AUTOPOLL_TYPE_DEP_PASSIVE_106;
+				*((u8 *)skb_put(skb, sizeof(u8))) =
+					PN532_AUTOPOLL_TYPE_DEP_PASSIVE_212;
+				*((u8 *)skb_put(skb, sizeof(u8))) =
+					PN532_AUTOPOLL_TYPE_DEP_PASSIVE_424;
+			}
+		}
+
+		if (im_protocols & NFC_PROTO_FELICA_MASK ||
+				im_protocols & NFC_PROTO_NFC_DEP_MASK) {
+			*((u8 *)skb_put(skb, sizeof(u8))) =
+				PN532_AUTOPOLL_TYPE_FELICA212;
+			*((u8 *)skb_put(skb, sizeof(u8))) =
+				PN532_AUTOPOLL_TYPE_FELICA424;
+		}
+
+		if (im_protocols & NFC_PROTO_JEWEL_MASK)
+			*((u8 *)skb_put(skb, sizeof(u8))) =
+				PN532_AUTOPOLL_TYPE_JEWEL;
+
+		if (im_protocols & NFC_PROTO_ISO14443_B_MASK)
+			*((u8 *)skb_put(skb, sizeof(u8))) =
+				PN532_AUTOPOLL_TYPE_ISOB;
+
+		if (tm_protocols)
+			*((u8 *)skb_put(skb, sizeof(u8))) =
+				PN532_AUTOPOLL_TYPE_DEP_ACTIVE_106;
+
+		rc = pn533_send_cmd_async(dev, PN533_CMD_IN_AUTOPOLL, skb,
+				pn533_autopoll_complete, NULL);
+
+		if (rc < 0)
+			dev_kfree_skb(skb);
+		else
+			dev->poll_mod_count++;
+
+		return rc;
+	}
+
+	pn533_poll_create_mod_list(dev, im_protocols, tm_protocols);
 
 	/* Do not always start polling from the same modulation */
 	get_random_bytes(&rand_mod, sizeof(rand_mod));
@@ -2461,7 +2647,8 @@ static int pn533_dev_up(struct nfc_dev *nfc_dev)
 	if (dev->phy_ops->dev_up)
 		dev->phy_ops->dev_up(dev);
 
-	if (dev->device_type == PN533_DEVICE_PN532) {
+	if ((dev->device_type == PN533_DEVICE_PN532) ||
+		(dev->device_type == PN533_DEVICE_PN532_AUTOPOLL)) {
 		int rc = pn532_sam_configuration(nfc_dev);
 
 		if (rc)
@@ -2508,6 +2695,7 @@ static int pn533_setup(struct pn533 *dev)
 	case PN533_DEVICE_PASORI:
 	case PN533_DEVICE_ACR122U:
 	case PN533_DEVICE_PN532:
+	case PN533_DEVICE_PN532_AUTOPOLL:
 		max_retries.mx_rty_atr = 0x2;
 		max_retries.mx_rty_psl = 0x1;
 		max_retries.mx_rty_passive_act =
@@ -2544,6 +2732,7 @@ static int pn533_setup(struct pn533 *dev)
 	switch (dev->device_type) {
 	case PN533_DEVICE_STD:
 	case PN533_DEVICE_PN532:
+	case PN533_DEVICE_PN532_AUTOPOLL:
 		break;
 
 	case PN533_DEVICE_PASORI:
diff --git a/drivers/nfc/pn533/pn533.h b/drivers/nfc/pn533/pn533.h
index 6541088fad73..388fc1b4fcc1 100644
--- a/drivers/nfc/pn533/pn533.h
+++ b/drivers/nfc/pn533/pn533.h
@@ -6,10 +6,11 @@
  * Copyright (C) 2012-2013 Tieto Poland
  */
 
-#define PN533_DEVICE_STD     0x1
-#define PN533_DEVICE_PASORI  0x2
-#define PN533_DEVICE_ACR122U 0x3
-#define PN533_DEVICE_PN532   0x4
+#define PN533_DEVICE_STD		0x1
+#define PN533_DEVICE_PASORI		0x2
+#define PN533_DEVICE_ACR122U		0x3
+#define PN533_DEVICE_PN532		0x4
+#define PN533_DEVICE_PN532_AUTOPOLL	0x5
 
 #define PN533_ALL_PROTOCOLS (NFC_PROTO_JEWEL_MASK | NFC_PROTO_MIFARE_MASK |\
 			     NFC_PROTO_FELICA_MASK | NFC_PROTO_ISO14443_MASK |\
@@ -75,6 +76,7 @@
 #define PN533_CMD_IN_ATR 0x50
 #define PN533_CMD_IN_RELEASE 0x52
 #define PN533_CMD_IN_JUMP_FOR_DEP 0x56
+#define PN533_CMD_IN_AUTOPOLL 0x60
 
 #define PN533_CMD_TG_INIT_AS_TARGET 0x8c
 #define PN533_CMD_TG_GET_DATA 0x86
-- 
2.23.0

[PATCH v9 7/7] nfc: pn532_uart: Make use of pn532 autopoll

[Lars Poeschel]

This switches the pn532 UART phy driver from manually polling to the new
autopoll mechanism.

Cc: Johan Hovold <johan@kernel.org>
Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
Changes in v9:
- Rebased the patch series on v5.4-rc2

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

 drivers/nfc/pn533/uart.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nfc/pn533/uart.c b/drivers/nfc/pn533/uart.c
index 7f639051cdd0..edf8db890eaa 100644
--- a/drivers/nfc/pn533/uart.c
+++ b/drivers/nfc/pn533/uart.c
@@ -262,7 +262,7 @@ static int pn532_uart_probe(struct serdev_device *serdev)
 	serdev_device_set_flow_control(serdev, false);
 	pn532->send_wakeup = PN532_SEND_WAKEUP;
 	timer_setup(&pn532->cmd_timeout, pn532_cmd_timeout, 0);
-	priv = pn53x_common_init(PN533_DEVICE_PN532,
+	priv = pn53x_common_init(PN533_DEVICE_PN532_AUTOPOLL,
 				     PN533_PROTO_REQ_ACK_RESP,
 				     pn532, &uart_phy_ops, NULL,
 				     &pn532->serdev->dev);
-- 
2.23.0

Re: [PATCH v9 2/7] nfc: pn532: Add uart phy docs and rename it

[Rob Herring]

On Tue,  8 Oct 2019 16:05:39 +0200, Lars Poeschel wrote:
> This adds documentation about the uart phy to the pn532 binding doc. As
> the filename "pn533-i2c.txt" is not appropriate any more, rename it to
> the more general "pn532.txt".
> This also documents the deprecation of the compatible strings ending
> with "...-i2c".
> 
> Cc: Johan Hovold <johan@kernel.org>
> Cc: Simon Horman <horms@verge.net.au>
> Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
> ---
> Changes in v9:
> - Rebased the patch series on v5.4-rc2
> - Produce patch with -M4 to git format-patch to detect the rename
> - Change DT node name from pn532@24 to nfc@24 in example
> 
> Changes in v8:
> - Update existing binding doc instead of adding a new one:
>   - Add uart phy example
>   - Add general "pn532" compatible string
>   - Deprecate "...-i2c" compatible strings
>   - Rename file to a more general filename
> - Intentionally drop Rob's Reviewed-By as I guess this rather big change
>   requires a new review
> 
> Changes in v7:
> - Accidentally lost Rob's Reviewed-By
> 
> Changes in v6:
> - Rebased the patch series on v5.3-rc5
> - Picked up Rob's Reviewed-By
> 
> Changes in v4:
> - Add documentation about reg property in case of i2c
> 
> Changes in v3:
> - seperate binding doc instead of entry in trivial-devices.txt
> 
>  .../net/nfc/{pn533-i2c.txt => pn532.txt}      | 25 ++++++++++++++++---
>  1 file changed, 21 insertions(+), 4 deletions(-)
>  rename Documentation/devicetree/bindings/net/nfc/{pn533-i2c.txt => pn532.txt} (42%)
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v9 0/7] nfc: pn533: add uart phy driver

[Jakub Kicinski]

On Tue,  8 Oct 2019 16:05:37 +0200, Lars Poeschel wrote:
> The purpose of this patch series is to add a uart phy driver to the
> pn533 nfc driver.
> It first changes the dt strings and docs. The dt compatible strings
> need to change, because I would add "pn532-uart" to the already
> existing "pn533-i2c" one. These two are now unified into just
> "pn532". Then the neccessary changes to the pn533 core driver are
> made. Then the uart phy is added.
> As the pn532 chip supports a autopoll, I wanted to use this instead
> of the software poll loop in the pn533 core driver. It is added and
> activated by the last to patches.
> The way to add the autopoll later in seperate patches is chosen, to
> show, that the uart phy driver can also work with the software poll
> loop, if someone needs that for some reason.
> This patchset is already rebased on Johans "NFC: pn533: fix
> use-after-free and memleaks" patch
> https://lore.kernel.org/netdev/20191007164059.5927-1-johan@kernel.org/
> as they would conflict.
> If for some reason Johans patch will not get merged, I can of course
> provide the patchset without depending on this patch.

The memleak patch was a fix and it's on its way to the current 5.4-rc
releases - therefore it was merged into the net tree. Your set adds
support for a new bus, and will go into the net-next tree.

It'd be best if you reposted once the net tree was merged into the
net-next tree (which usually happens every week or two). If you'd
rather not wait you need to rebase on top of the current net-next tree,
and maintainers will handle the conflicts.

Re: [PATCH v9 4/7] nfc: pn533: Split pn533 init & nfc_register

[Jakub Kicinski]

On Tue,  8 Oct 2019 16:05:41 +0200, Lars Poeschel wrote:
> 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.
> 
> Cc: Johan Hovold <johan@kernel.org>
> Cc: Claudiu Beznea <Claudiu.Beznea@microchip.com>
> Signed-off-by: Lars Poeschel <poeschel@lemonage.de>

> diff --git a/drivers/nfc/pn533/i2c.c b/drivers/nfc/pn533/i2c.c
> index 1abd40398a5a..e9e5a1ec8857 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,
> +	priv = pn53x_common_init(PN533_DEVICE_PN532,
>  				     PN533_PROTO_REQ_ACK_RESP,
>  				     phy, &i2c_phy_ops, NULL,
> -				     &phy->i2c_dev->dev,
> -				     &client->dev);
> +				     &phy->i2c_dev->dev);

nit: start of continuation lines should match the opening parenthesis,
     please run checkpatch and fix the style issue

>  	if (IS_ERR(priv)) {
>  		r = PTR_ERR(priv);
> @@ -220,13 +218,17 @@ static int pn533_i2c_probe(struct i2c_client *client,
>  	if (r)
>  		goto fn_setup_err;
>  
> -	return 0;
> +	r = pn53x_register_nfc(priv, PN533_NO_TYPE_B_PROTOCOLS, &client->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);
> +	pn53x_common_clean(phy->priv);
>  
>  	return r;
>  }
> @@ -239,7 +241,8 @@ 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..e5d5e4c83a04 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;

Aren't you moving too much out of here? Looking at commit 32ecc75ded72
("NFC: pn533: change order operations in dev registation") it seems like
IRQ handler may want to access the data structures, do this change not
reintroduce the problem?

>  	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);
>  

Re: [PATCH v9 4/7] nfc: pn533: Split pn533 init & nfc_register

[Lars Poeschel]

On Wed, Oct 09, 2019 at 05:40:23PM -0700, Jakub Kicinski wrote:
> On Tue,  8 Oct 2019 16:05:41 +0200, Lars Poeschel wrote:
> > 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.
> > 
> > Cc: Johan Hovold <johan@kernel.org>
> > Cc: Claudiu Beznea <Claudiu.Beznea@microchip.com>
> > Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
> 
> > diff --git a/drivers/nfc/pn533/i2c.c b/drivers/nfc/pn533/i2c.c
> > index 1abd40398a5a..e9e5a1ec8857 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,
> > +	priv = pn53x_common_init(PN533_DEVICE_PN532,
> >  				     PN533_PROTO_REQ_ACK_RESP,
> >  				     phy, &i2c_phy_ops, NULL,
> > -				     &phy->i2c_dev->dev,
> > -				     &client->dev);
> > +				     &phy->i2c_dev->dev);
> 
> nit: start of continuation lines should match the opening parenthesis,
>      please run checkpatch and fix the style issue

Ok, I will change that.

> >  	if (IS_ERR(priv)) {
> >  		r = PTR_ERR(priv);
> > @@ -220,13 +218,17 @@ static int pn533_i2c_probe(struct i2c_client *client,
> >  	if (r)
> >  		goto fn_setup_err;
> >  
> > -	return 0;
> > +	r = pn53x_register_nfc(priv, PN533_NO_TYPE_B_PROTOCOLS, &client->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);
> > +	pn53x_common_clean(phy->priv);
> >  
> >  	return r;
> >  }
> > @@ -239,7 +241,8 @@ 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..e5d5e4c83a04 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;
> 
> Aren't you moving too much out of here? Looking at commit 32ecc75ded72
> ("NFC: pn533: change order operations in dev registation") it seems like
> IRQ handler may want to access the data structures, do this change not
> reintroduce the problem?

Yes, you are right, there could be a problem if an irq gets served
before the driver is registered to the nfc subsystem.
Well, but the purpose of this patch is exactly that: Prevent use of nfc
subsystem before the chip is fully initialized.
To address this, I would not change the part above, but move the
request_threaded_irq to the very bottom in pn533_i2c_probe, after the
call to pn53x_register_nfc. So it is not possible to use nfc before the
chip is initialized and irqs don't get served before the driver is
registered to nfc subsystem.
Thank you for this!
I will include this in v10 of the patchset.

> >  	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);
> >  
> 

Re: [PATCH v9 0/7] nfc: pn533: add uart phy driver

[Lars Poeschel]

On Wed, Oct 09, 2019 at 05:29:07PM -0700, Jakub Kicinski wrote:
> On Tue,  8 Oct 2019 16:05:37 +0200, Lars Poeschel wrote:
> > The purpose of this patch series is to add a uart phy driver to the
> > pn533 nfc driver.
> > It first changes the dt strings and docs. The dt compatible strings
> > need to change, because I would add "pn532-uart" to the already
> > existing "pn533-i2c" one. These two are now unified into just
> > "pn532". Then the neccessary changes to the pn533 core driver are
> > made. Then the uart phy is added.
> > As the pn532 chip supports a autopoll, I wanted to use this instead
> > of the software poll loop in the pn533 core driver. It is added and
> > activated by the last to patches.
> > The way to add the autopoll later in seperate patches is chosen, to
> > show, that the uart phy driver can also work with the software poll
> > loop, if someone needs that for some reason.
> > This patchset is already rebased on Johans "NFC: pn533: fix
> > use-after-free and memleaks" patch
> > https://lore.kernel.org/netdev/20191007164059.5927-1-johan@kernel.org/
> > as they would conflict.
> > If for some reason Johans patch will not get merged, I can of course
> > provide the patchset without depending on this patch.
> 
> The memleak patch was a fix and it's on its way to the current 5.4-rc
> releases - therefore it was merged into the net tree. Your set adds
> support for a new bus, and will go into the net-next tree.
> 
> It'd be best if you reposted once the net tree was merged into the
> net-next tree (which usually happens every week or two). If you'd
> rather not wait you need to rebase on top of the current net-next tree,
> and maintainers will handle the conflicts.

Thank you very much for this valueable information. I will repost the
v10 of this patchset rebased on net-next, when the fix is appears there.

Re: [PATCH v9 4/7] nfc: pn533: Split pn533 init & nfc_register

[Jakub Kicinski]

On Tue, 15 Oct 2019 11:51:24 +0200, Lars Poeschel wrote:
> > > -	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;  
> > 
> > Aren't you moving too much out of here? Looking at commit 32ecc75ded72
> > ("NFC: pn533: change order operations in dev registation") it seems like
> > IRQ handler may want to access the data structures, do this change not
> > reintroduce the problem?  
> 
> Yes, you are right, there could be a problem if an irq gets served
> before the driver is registered to the nfc subsystem.
> Well, but the purpose of this patch is exactly that: Prevent use of nfc
> subsystem before the chip is fully initialized.
> To address this, I would not change the part above, but move the
> request_threaded_irq to the very bottom in pn533_i2c_probe, after the
> call to pn53x_register_nfc. So it is not possible to use nfc before the
> chip is initialized and irqs don't get served before the driver is
> registered to nfc subsystem.
> Thank you for this!
> I will include this in v10 of the patchset.

You can run nfc_allocate_device() etc. early, then allocate the IRQ,
and then run nfc_register_device(), would that work? Is that what you
have in mind?

Re: [PATCH v9 4/7] nfc: pn533: Split pn533 init & nfc_register

[Lars Poeschel]

On Tue, Oct 15, 2019 at 09:16:42AM -0700, Jakub Kicinski wrote:
> On Tue, 15 Oct 2019 11:51:24 +0200, Lars Poeschel wrote:
> > > > -	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;  
> > > 
> > > Aren't you moving too much out of here? Looking at commit 32ecc75ded72
> > > ("NFC: pn533: change order operations in dev registation") it seems like
> > > IRQ handler may want to access the data structures, do this change not
> > > reintroduce the problem?  
> > 
> > Yes, you are right, there could be a problem if an irq gets served
> > before the driver is registered to the nfc subsystem.
> > Well, but the purpose of this patch is exactly that: Prevent use of nfc
> > subsystem before the chip is fully initialized.
> > To address this, I would not change the part above, but move the
> > request_threaded_irq to the very bottom in pn533_i2c_probe, after the
> > call to pn53x_register_nfc. So it is not possible to use nfc before the
> > chip is initialized and irqs don't get served before the driver is
> > registered to nfc subsystem.
> > Thank you for this!
> > I will include this in v10 of the patchset.
> 
> You can run nfc_allocate_device() etc. early, then allocate the IRQ,
> and then run nfc_register_device(), would that work? Is that what you
> have in mind?

Well, I think my proposed solution above would technically do it, but I
think I will do it like you proposed. I think for someone reading the
code it is far more easier to understand, what the idea behind it is, if
the irq is requested right between nfc_allocate_device and
nfc_register_device.
Thanks again!