[PATCH v4 1/6] nfc: pn533: i2c: "pn532" as dt compatible string

[PATCH v4 1/6] 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.

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
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 4389eb4c8d0b..f4eae9dd5305 100644
--- a/drivers/nfc/pn533/i2c.c
+++ b/drivers/nfc/pn533/i2c.c
@@ -258,6 +258,11 @@ 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", },
 	{},
-- 
2.19.1

[PATCH v4 2/6] nfc: pn532_uart: Add NXP PN532 to devicetree docs

[Lars Poeschel]

Add a simple binding doc for the pn532.

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
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

 .../devicetree/bindings/nfc/pn532.txt         | 33 +++++++++++++++++++
 1 file changed, 33 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/nfc/pn532.txt

diff --git a/Documentation/devicetree/bindings/nfc/pn532.txt b/Documentation/devicetree/bindings/nfc/pn532.txt
new file mode 100644
index 000000000000..d5aaa588073d
--- /dev/null
+++ b/Documentation/devicetree/bindings/nfc/pn532.txt
@@ -0,0 +1,33 @@
+NXP PN532 NFC Chip
+
+Required properties:
+- 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:
+- reg: for the i2c bus address. This is fixed at 0x48 for the PN532.
+
+Example uart:
+
+uart4: serial@49042000 {
+        compatible = "ti,omap3-uart";
+
+        pn532: nfc {
+                compatible = "nxp,pn532";
+        };
+};
+
+Example i2c:
+
+i2c1: i2c@0 {
+        compatible = "ti,omap3-i2c";
+
+        pn532: nfc {
+                compatible = "nxp,pn532";
+                reg = <0x48>;
+        };
+};
-- 
2.19.1

[PATCH v4 3/6] 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.

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
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 a0cc1cc45292..f0c541152777 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -2468,6 +2468,9 @@ static int pn533_dev_up(struct nfc_dev *nfc_dev)
 {
 	struct pn533 *dev = nfc_get_drvdata(nfc_dev);
 
+	if (dev->phy_ops)
+		dev->phy_ops->dev_up(dev);
+
 	if (dev->device_type == PN533_DEVICE_PN532) {
 		int rc = pn532_sam_configuration(nfc_dev);
 
@@ -2480,7 +2483,14 @@ 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 && !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 88d569666c51..eb5ccefc32e5 100644
--- a/drivers/nfc/pn533/pn533.h
+++ b/drivers/nfc/pn533/pn533.h
@@ -219,6 +219,15 @@ 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);
 };
 
 
-- 
2.19.1

[PATCH v4 4/6] 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.

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
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   | 311 +++++++++++++++++++++++++++++++++++++
 4 files changed, 332 insertions(+)
 create mode 100644 drivers/nfc/pn533/uart.c

diff --git a/drivers/nfc/pn533/Kconfig b/drivers/nfc/pn533/Kconfig
index d94122dd30e4..29df7d97d209 100644
--- a/drivers/nfc/pn533/Kconfig
+++ b/drivers/nfc/pn533/Kconfig
@@ -25,3 +25,14 @@ 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 51d24c622fcb..bdfd6860d5e4 100644
--- a/drivers/nfc/pn533/Makefile
+++ b/drivers/nfc/pn533/Makefile
@@ -3,7 +3,9 @@
 #
 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 eb5ccefc32e5..d1a0543f66a8 100644
--- a/drivers/nfc/pn533/pn533.h
+++ b/drivers/nfc/pn533/pn533.h
@@ -55,6 +55,11 @@
 
 /* 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 */
@@ -96,6 +101,9 @@
 #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..7df6d2fb8466
--- /dev/null
+++ b/drivers/nfc/pn533/uart.c
@@ -0,0 +1,311 @@
+// 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;
+	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)
+{
+	struct pn532_uart_phy *pn532 = dev->phy;
+	/* 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};
+	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)
+{
+	int i;
+	u16 frame_len;
+	struct pn533_std_frame *std;
+	struct pn533_ext_frame *ext;
+
+	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-uart", },
+	{},
+};
+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 = pn533_register_device(PN533_DEVICE_PN532,
+				     PN533_NO_TYPE_B_PROTOCOLS,
+				     PN533_PROTO_REQ_ACK_RESP,
+				     pn532, &uart_phy_ops, NULL,
+				     &pn532->serdev->dev,
+				     &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_unregister;
+
+	serdev_device_close(serdev);
+	return 0;
+
+err_unregister:
+	pn533_unregister_device(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);
+
+	pn533_unregister_device(pn532->priv);
+	serdev_device_close(serdev);
+	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");
-- 
2.19.1

[PATCH v4 5/6] 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.

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 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 f0c541152777..8c21ee72832f 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -197,6 +197,32 @@ struct pn533_cmd_jump_dep_response {
 	u8 gt[];
 } __packed;
 
+struct pn532_autopoll_resp {
+	u8 type;
+	u8 ln;
+	u8 tg;
+	u8 tgdata[];
+} __packed;
+
+/* 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
@@ -1401,6 +1427,101 @@ 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)
+{
+	u8 nbtg;
+	int rc;
+	struct pn532_autopoll_resp *apr;
+	struct nfc_target nfc_tgt;
+
+	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");
+			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");
+			rc = pn533_target_found_felica(&nfc_tgt, apr->tgdata,
+						       apr->ln - 1);
+			break;
+		case PN532_AUTOPOLL_TYPE_JEWEL:
+			dev_dbg(dev->dev, "JEWEL");
+			rc = pn533_target_found_jewel(&nfc_tgt, apr->tgdata,
+						      apr->ln - 1);
+			break;
+		case PN532_AUTOPOLL_TYPE_ISOB:
+			dev_dbg(dev->dev, "ISOB");
+			rc = pn533_target_found_type_b(&nfc_tgt, apr->tgdata,
+						       apr->ln - 1);
+			break;
+		case PN532_AUTOPOLL_TYPE_MIFARE:
+			dev_dbg(dev->dev, "Mifare");
+			rc = pn533_target_found_type_a(&nfc_tgt, apr->tgdata,
+						       apr->ln - 1);
+			break;
+		default:
+			nfc_err(dev->dev,
+				    "Unknown current poll modulation");
+			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");
+			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)
 {
@@ -1546,6 +1667,7 @@ static int pn533_start_poll(struct nfc_dev *nfc_dev,
 	struct pn533_poll_modulations *cur_mod;
 	u8 rand_mod;
 	int rc;
+	struct sk_buff *skb;
 
 	dev_dbg(dev->dev,
 		"%s: im protocols 0x%x tm protocols 0x%x\n",
@@ -1569,9 +1691,73 @@ 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));
@@ -2471,7 +2657,8 @@ static int pn533_dev_up(struct nfc_dev *nfc_dev)
 	if (dev->phy_ops)
 		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)
@@ -2518,6 +2705,7 @@ 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 =
@@ -2554,6 +2742,7 @@ 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 d1a0543f66a8..e0636263911d 100644
--- a/drivers/nfc/pn533/pn533.h
+++ b/drivers/nfc/pn533/pn533.h
@@ -18,10 +18,11 @@
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
-#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 |\
@@ -87,6 +88,7 @@
 #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
-- 
2.19.1

[PATCH v4 6/6] 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.

Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
---
 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 7df6d2fb8466..1d862caeda55 100644
--- a/drivers/nfc/pn533/uart.c
+++ b/drivers/nfc/pn533/uart.c
@@ -254,7 +254,7 @@ 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 = pn533_register_device(PN533_DEVICE_PN532,
+	priv = pn533_register_device(PN533_DEVICE_PN532_AUTOPOLL,
 				     PN533_NO_TYPE_B_PROTOCOLS,
 				     PN533_PROTO_REQ_ACK_RESP,
 				     pn532, &uart_phy_ops, NULL,
-- 
2.19.1

Re: [PATCH v4 2/6] nfc: pn532_uart: Add NXP PN532 to devicetree docs

[Rob Herring]

On Thu,  1 Nov 2018 11:02:10 +0100, Lars Poeschel wrote:
> Add a simple binding doc for the pn532.
> 
> Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
> ---
> 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
> 
>  .../devicetree/bindings/nfc/pn532.txt         | 33 +++++++++++++++++++
>  1 file changed, 33 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/nfc/pn532.txt
> 

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

Re: [PATCH v4 4/6] nfc: pn533: add UART phy driver

[Johan Hovold]

On Thu, Nov 01, 2018 at 11:02:12AM +0100, Lars Poeschel wrote:
> 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.
> 
> Signed-off-by: Lars Poeschel <poeschel@lemonage.de>

Please make sure to include reviewers on CC.

> ---
> 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   | 311 +++++++++++++++++++++++++++++++++++++
>  4 files changed, 332 insertions(+)
>  create mode 100644 drivers/nfc/pn533/uart.c
> 
> +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 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 = pn533_register_device(PN533_DEVICE_PN532,
> +				     PN533_NO_TYPE_B_PROTOCOLS,
> +				     PN533_PROTO_REQ_ACK_RESP,
> +				     pn532, &uart_phy_ops, NULL,
> +				     &pn532->serdev->dev,
> +				     &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_unregister;
> +
> +	serdev_device_close(serdev);

This looks broken; what if the NFC interface is brought up before this
point? You'd get a double open, which is likely to crash things, but
even if you survive that, the port would not be closed despite the
interface being up.

Can't you finalise your setup before registering the interface?

> +	return 0;
> +
> +err_unregister:
> +	pn533_unregister_device(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);
> +
> +	pn533_unregister_device(pn532->priv);
> +	serdev_device_close(serdev);

This is also broken; the port should have been closed when the interface
was deregistered.

> +	kfree_skb(pn532->recv_skb);
> +	kfree(pn532);
> +}

Johan

Re: [PATCH v4 4/6] nfc: pn533: add UART phy driver

[Lars Poeschel]

On Wed, Nov 14, 2018 at 04:35:17PM +0100, Johan Hovold wrote:
> On Thu, Nov 01, 2018 at 11:02:12AM +0100, Lars Poeschel wrote:
> > 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.
> > 
> > Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
> 
> Please make sure to include reviewers on CC.

It's hard to do all things right, about how to correctly email patches,
patch sets and follow ups and send what to whom.
I am still learning. Sorry about that.

> > ---
> > 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   | 311 +++++++++++++++++++++++++++++++++++++
> >  4 files changed, 332 insertions(+)
> >  create mode 100644 drivers/nfc/pn533/uart.c
> > 
> > +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 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 = pn533_register_device(PN533_DEVICE_PN532,
> > +				     PN533_NO_TYPE_B_PROTOCOLS,
> > +				     PN533_PROTO_REQ_ACK_RESP,
> > +				     pn532, &uart_phy_ops, NULL,
> > +				     &pn532->serdev->dev,
> > +				     &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_unregister;
> > +
> > +	serdev_device_close(serdev);
> 
> This looks broken; what if the NFC interface is brought up before this
> point? You'd get a double open, which is likely to crash things, but
> even if you survive that, the port would not be closed despite the
> interface being up.

I understand the problem and would like to solve it with a mutex. I will
not have time to work on that until next year. Please be patient. I will
send a new patchset.

> Can't you finalise your setup before registering the interface?

Well, propably I can do that. But I did it the way the other drivers
(usb and i2c) are already doing and reusing the code of the pn533 core
driver. Since their probe works very similar to mine, I suspect them to
have the same problems.
I can rewrite the probe for my driver, but not for the other two. I can
not test them.
Would you prefer that I rewrite my own _register_device and
_finalize_setup functions, not using the ones from the core driver ?

> > +	return 0;
> > +
> > +err_unregister:
> > +	pn533_unregister_device(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);
> > +
> > +	pn533_unregister_device(pn532->priv);
> > +	serdev_device_close(serdev);
> 
> This is also broken; the port should have been closed when the interface
> was deregistered.

Same as above.

> > +	kfree_skb(pn532->recv_skb);
> > +	kfree(pn532);
> > +}

Thank you for your very valuable feedback.

Regards,
Lars

Re: [PATCH v4 4/6] nfc: pn533: add UART phy driver

[Johan Hovold]

On Mon, Dec 03, 2018 at 03:26:22PM +0100, Lars Poeschel wrote:
> On Wed, Nov 14, 2018 at 04:35:17PM +0100, Johan Hovold wrote:
> > On Thu, Nov 01, 2018 at 11:02:12AM +0100, Lars Poeschel wrote:
> > > 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.
> > > 
> > > Signed-off-by: Lars Poeschel <poeschel@lemonage.de>
> > 
> > Please make sure to include reviewers on CC.
> 
> It's hard to do all things right, about how to correctly email patches,
> patch sets and follow ups and send what to whom.
> I am still learning. Sorry about that.

No problem, I fully understand that.

> > > +	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 = pn533_register_device(PN533_DEVICE_PN532,
> > > +				     PN533_NO_TYPE_B_PROTOCOLS,
> > > +				     PN533_PROTO_REQ_ACK_RESP,
> > > +				     pn532, &uart_phy_ops, NULL,
> > > +				     &pn532->serdev->dev,
> > > +				     &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_unregister;
> > > +
> > > +	serdev_device_close(serdev);
> > 
> > This looks broken; what if the NFC interface is brought up before this
> > point? You'd get a double open, which is likely to crash things, but
> > even if you survive that, the port would not be closed despite the
> > interface being up.
> 
> I understand the problem and would like to solve it with a mutex. I will
> not have time to work on that until next year. Please be patient. I will
> send a new patchset.

I'm in no hurry here. :)

But I still think doing that setup before registering the device might
be preferred if it's possible as you wouldn't need a mutex then.

> > Can't you finalise your setup before registering the interface?
> 
> Well, propably I can do that. But I did it the way the other drivers
> (usb and i2c) are already doing and reusing the code of the pn533 core
> driver. Since their probe works very similar to mine, I suspect them to
> have the same problems.

Quite possibly.

> I can rewrite the probe for my driver, but not for the other two. I can
> not test them.
> Would you prefer that I rewrite my own _register_device and
> _finalize_setup functions, not using the ones from the core driver ?

If you add common paths that you can test using your driver I think it
should be fine to convert the others unless it ends up being really
complicated. Perhaps the authors of those driver can help out with
testing too.

> Thank you for your very valuable feedback.

You're welcome.

Johan