NFC: pn533: add NXP pn533 nfc device driver

Signed-off-by: Lauro Ramos Venancio <lauro.venancio@openbossa.org>
Signed-off-by: Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 1632 insertions, 0 deletions

diff --git a/drivers/nfc/pn533.c b/drivers/nfc/pn533.c
new file mode 100644
index 000000000000..037231540719
--- /dev/null
+++ b/drivers/nfc/pn533.c
@@ -0,0 +1,1632 @@
+/*
+ * Copyright (C) 2011 Instituto Nokia de Tecnologia
+ *
+ * Authors:
+ *    Lauro Ramos Venancio <lauro.venancio@openbossa.org>
+ *    Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the
+ * Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/nfc.h>
+#include <linux/netdevice.h>
+#include <net/nfc.h>
+
+#define VERSION "0.1"
+
+#define PN533_VENDOR_ID 0x4CC
+#define PN533_PRODUCT_ID 0x2533
+
+#define SCM_VENDOR_ID 0x4E6
+#define SCL3711_PRODUCT_ID 0x5591
+
+static const struct usb_device_id pn533_table[] = {
+	{ USB_DEVICE(PN533_VENDOR_ID, PN533_PRODUCT_ID) },
+	{ USB_DEVICE(SCM_VENDOR_ID, SCL3711_PRODUCT_ID) },
+	{ }
+};
+MODULE_DEVICE_TABLE(usb, pn533_table);
+
+/* frame definitions */
+#define PN533_FRAME_TAIL_SIZE 2
+#define PN533_FRAME_SIZE(f) (sizeof(struct pn533_frame) + f->datalen + \
+				PN533_FRAME_TAIL_SIZE)
+#define PN533_FRAME_ACK_SIZE (sizeof(struct pn533_frame) + 1)
+#define PN533_FRAME_CHECKSUM(f) (f->data[f->datalen])
+#define PN533_FRAME_POSTAMBLE(f) (f->data[f->datalen + 1])
+
+/* start of frame */
+#define PN533_SOF 0x00FF
+
+/* frame identifier: in/out/error */
+#define PN533_FRAME_IDENTIFIER(f) (f->data[0])
+#define PN533_DIR_OUT 0xD4
+#define PN533_DIR_IN 0xD5
+
+/* PN533 Commands */
+#define PN533_FRAME_CMD(f) (f->data[1])
+#define PN533_FRAME_CMD_PARAMS_PTR(f) (&f->data[2])
+#define PN533_FRAME_CMD_PARAMS_LEN(f) (f->datalen - 2)
+
+#define PN533_CMD_GET_FIRMWARE_VERSION 0x02
+#define PN533_CMD_RF_CONFIGURATION 0x32
+#define PN533_CMD_IN_DATA_EXCHANGE 0x40
+#define PN533_CMD_IN_LIST_PASSIVE_TARGET 0x4A
+#define PN533_CMD_IN_ATR 0x50
+#define PN533_CMD_IN_RELEASE 0x52
+
+#define PN533_CMD_RESPONSE(cmd) (cmd + 1)
+
+/* PN533 Return codes */
+#define PN533_CMD_RET_MASK 0x3F
+#define PN533_CMD_MI_MASK 0x40
+#define PN533_CMD_RET_SUCCESS 0x00
+
+struct pn533;
+
+typedef int (*pn533_cmd_complete_t) (struct pn533 *dev, void *arg,
+					u8 *params, int params_len);
+
+/* structs for pn533 commands */
+
+/* PN533_CMD_GET_FIRMWARE_VERSION */
+struct pn533_fw_version {
+	u8 ic;
+	u8 ver;
+	u8 rev;
+	u8 support;
+};
+
+/* PN533_CMD_RF_CONFIGURATION */
+#define PN533_CFGITEM_MAX_RETRIES 0x05
+
+#define PN533_CONFIG_MAX_RETRIES_NO_RETRY 0x00
+#define PN533_CONFIG_MAX_RETRIES_ENDLESS 0xFF
+
+struct pn533_config_max_retries {
+	u8 mx_rty_atr;
+	u8 mx_rty_psl;
+	u8 mx_rty_passive_act;
+} __packed;
+
+/* PN533_CMD_IN_LIST_PASSIVE_TARGET */
+
+/* felica commands opcode */
+#define PN533_FELICA_OPC_SENSF_REQ 0
+#define PN533_FELICA_OPC_SENSF_RES 1
+/* felica SENSF_REQ parameters */
+#define PN533_FELICA_SENSF_SC_ALL 0xFFFF
+#define PN533_FELICA_SENSF_RC_NO_SYSTEM_CODE 0
+#define PN533_FELICA_SENSF_RC_SYSTEM_CODE 1
+#define PN533_FELICA_SENSF_RC_ADVANCED_PROTOCOL 2
+
+/* type B initiator_data values */
+#define PN533_TYPE_B_AFI_ALL_FAMILIES 0
+#define PN533_TYPE_B_POLL_METHOD_TIMESLOT 0
+#define PN533_TYPE_B_POLL_METHOD_PROBABILISTIC 1
+
+union pn533_cmd_poll_initdata {
+	struct {
+		u8 afi;
+		u8 polling_method;
+	} __packed type_b;
+	struct {
+		u8 opcode;
+		__be16 sc;
+		u8 rc;
+		u8 tsn;
+	} __packed felica;
+};
+
+/* Poll modulations */
+enum {
+	PN533_POLL_MOD_106KBPS_A,
+	PN533_POLL_MOD_212KBPS_FELICA,
+	PN533_POLL_MOD_424KBPS_FELICA,
+	PN533_POLL_MOD_106KBPS_JEWEL,
+	PN533_POLL_MOD_847KBPS_B,
+
+	__PN533_POLL_MOD_AFTER_LAST,
+};
+#define PN533_POLL_MOD_MAX (__PN533_POLL_MOD_AFTER_LAST - 1)
+
+struct pn533_poll_modulations {
+	struct {
+		u8 maxtg;
+		u8 brty;
+		union pn533_cmd_poll_initdata initiator_data;
+	} __packed data;
+	u8 len;
+};
+
+const struct pn533_poll_modulations poll_mod[] = {
+	[PN533_POLL_MOD_106KBPS_A] = {
+		.data = {
+			.maxtg = 1,
+			.brty = 0,
+		},
+		.len = 2,
+	},
+	[PN533_POLL_MOD_212KBPS_FELICA] = {
+		.data = {
+			.maxtg = 1,
+			.brty = 1,
+			.initiator_data.felica = {
+				.opcode = PN533_FELICA_OPC_SENSF_REQ,
+				.sc = PN533_FELICA_SENSF_SC_ALL,
+				.rc = PN533_FELICA_SENSF_RC_NO_SYSTEM_CODE,
+				.tsn = 0,
+			},
+		},
+		.len = 7,
+	},
+	[PN533_POLL_MOD_424KBPS_FELICA] = {
+		.data = {
+			.maxtg = 1,
+			.brty = 2,
+			.initiator_data.felica = {
+				.opcode = PN533_FELICA_OPC_SENSF_REQ,
+				.sc = PN533_FELICA_SENSF_SC_ALL,
+				.rc = PN533_FELICA_SENSF_RC_NO_SYSTEM_CODE,
+				.tsn = 0,
+			},
+		 },
+		.len = 7,
+	},
+	[PN533_POLL_MOD_106KBPS_JEWEL] = {
+		.data = {
+			.maxtg = 1,
+			.brty = 4,
+		},
+		.len = 2,
+	},
+	[PN533_POLL_MOD_847KBPS_B] = {
+		.data = {
+			.maxtg = 1,
+			.brty = 8,
+			.initiator_data.type_b = {
+				.afi = PN533_TYPE_B_AFI_ALL_FAMILIES,
+				.polling_method =
+					PN533_TYPE_B_POLL_METHOD_TIMESLOT,
+			},
+		},
+		.len = 3,
+	},
+};
+
+/* PN533_CMD_IN_ATR */
+
+struct pn533_cmd_activate_param {
+	u8 tg;
+	u8 next;
+} __packed;
+
+struct pn533_cmd_activate_response {
+	u8 status;
+	u8 nfcid3t[10];
+	u8 didt;
+	u8 bst;
+	u8 brt;
+	u8 to;
+	u8 ppt;
+	/* optional */
+	u8 gt[];
+} __packed;
+
+
+struct pn533 {
+	struct usb_device *udev;
+	struct usb_interface *interface;
+	struct nfc_dev *nfc_dev;
+
+	struct urb *out_urb;
+	int out_maxlen;
+	struct pn533_frame *out_frame;
+
+	struct urb *in_urb;
+	int in_maxlen;
+	struct pn533_frame *in_frame;
+
+	struct tasklet_struct tasklet;
+	struct pn533_frame *tklt_in_frame;
+	int tklt_in_error;
+
+	pn533_cmd_complete_t cmd_complete;
+	void *cmd_complete_arg;
+	struct semaphore cmd_lock;
+	u8 cmd;
+
+	struct pn533_poll_modulations *poll_mod_active[PN533_POLL_MOD_MAX + 1];
+	u8 poll_mod_count;
+	u8 poll_mod_curr;
+	u32 poll_protocols;
+
+	u8 tgt_available_prots;
+	u8 tgt_active_prot;
+};
+
+struct pn533_frame {
+	u8 preamble;
+	__be16 start_frame;
+	u8 datalen;
+	u8 datalen_checksum;
+	u8 data[];
+} __packed;
+
+/* The rule: value + checksum = 0 */
+static inline u8 pn533_checksum(u8 value)
+{
+	return ~value + 1;
+}
+
+/* The rule: sum(data elements) + checksum = 0 */
+static u8 pn533_data_checksum(u8 *data, int datalen)
+{
+	u8 sum = 0;
+	int i;
+
+	for (i = 0; i < datalen; i++)
+		sum += data[i];
+
+	return pn533_checksum(sum);
+}
+
+/**
+ * pn533_tx_frame_ack - create a ack frame
+ * @frame:	The frame to be set as ack
+ *
+ * Ack is different type of standard frame. As a standard frame, it has
+ * preamble and start_frame. However the checksum of this frame must fail,
+ * i.e. datalen + datalen_checksum must NOT be zero. When the checksum test
+ * fails and datalen = 0 and datalen_checksum = 0xFF, the frame is a ack.
+ * After datalen_checksum field, the postamble is placed.
+ */
+static void pn533_tx_frame_ack(struct pn533_frame *frame)
+{
+	frame->preamble = 0;
+	frame->start_frame = cpu_to_be16(PN533_SOF);
+	frame->datalen = 0;
+	frame->datalen_checksum = 0xFF;
+	/* data[0] is used as postamble */
+	frame->data[0] = 0;
+}
+
+static void pn533_tx_frame_init(struct pn533_frame *frame, u8 cmd)
+{
+	frame->preamble = 0;
+	frame->start_frame = cpu_to_be16(PN533_SOF);
+	PN533_FRAME_IDENTIFIER(frame) = PN533_DIR_OUT;
+	PN533_FRAME_CMD(frame) = cmd;
+	frame->datalen = 2;
+}
+
+static void pn533_tx_frame_finish(struct pn533_frame *frame)
+{
+	frame->datalen_checksum = pn533_checksum(frame->datalen);
+
+	PN533_FRAME_CHECKSUM(frame) =
+		pn533_data_checksum(frame->data, frame->datalen);
+
+	PN533_FRAME_POSTAMBLE(frame) = 0;
+}
+
+static bool pn533_rx_frame_is_valid(struct pn533_frame *frame)
+{
+	u8 checksum;
+
+	if (frame->start_frame != cpu_to_be16(PN533_SOF))
+		return false;
+
+	checksum = pn533_checksum(frame->datalen);
+	if (checksum != frame->datalen_checksum)
+		return false;
+
+	checksum = pn533_data_checksum(frame->data, frame->datalen);
+	if (checksum != PN533_FRAME_CHECKSUM(frame))
+		return false;
+
+	return true;
+}
+
+static bool pn533_rx_frame_is_ack(struct pn533_frame *frame)
+{
+	if (frame->start_frame != cpu_to_be16(PN533_SOF))
+		return false;
+
+	if (frame->datalen != 0 || frame->datalen_checksum != 0xFF)
+		return false;
+
+	return true;
+}
+
+static bool pn533_rx_frame_is_cmd_response(struct pn533_frame *frame, u8 cmd)
+{
+	return (PN533_FRAME_CMD(frame) == PN533_CMD_RESPONSE(cmd));
+}
+
+static void pn533_tasklet_cmd_complete(unsigned long arg)
+{
+	struct pn533 *dev = (struct pn533 *) arg;
+	struct pn533_frame *in_frame = dev->tklt_in_frame;
+	int rc;
+
+	if (dev->tklt_in_error)
+		rc = dev->cmd_complete(dev, dev->cmd_complete_arg, NULL,
+							dev->tklt_in_error);
+	else
+		rc = dev->cmd_complete(dev, dev->cmd_complete_arg,
+					PN533_FRAME_CMD_PARAMS_PTR(in_frame),
+					PN533_FRAME_CMD_PARAMS_LEN(in_frame));
+
+	if (rc != -EINPROGRESS)
+		up(&dev->cmd_lock);
+}
+
+static void pn533_recv_response(struct urb *urb)
+{
+	struct pn533 *dev = urb->context;
+	struct pn533_frame *in_frame;
+
+	dev->tklt_in_frame = NULL;
+
+	switch (urb->status) {
+	case 0:
+		/* success */
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		nfc_dev_dbg(&dev->interface->dev, "Urb shutting down with"
+						" status: %d", urb->status);
+		dev->tklt_in_error = urb->status;
+		goto sched_tasklet;
+	default:
+		nfc_dev_err(&dev->interface->dev, "Nonzero urb status received:"
+							" %d", urb->status);
+		dev->tklt_in_error = urb->status;
+		goto sched_tasklet;
+	}
+
+	in_frame = dev->in_urb->transfer_buffer;
+
+	if (!pn533_rx_frame_is_valid(in_frame)) {
+		nfc_dev_err(&dev->interface->dev, "Received an invalid frame");
+		dev->tklt_in_error = -EIO;
+		goto sched_tasklet;
+	}
+
+	if (!pn533_rx_frame_is_cmd_response(in_frame, dev->cmd)) {
+		nfc_dev_err(&dev->interface->dev, "The received frame is not "
+						"response to the last command");
+		dev->tklt_in_error = -EIO;
+		goto sched_tasklet;
+	}
+
+	nfc_dev_dbg(&dev->interface->dev, "Received a valid frame");
+	dev->tklt_in_error = 0;
+	dev->tklt_in_frame = in_frame;
+
+sched_tasklet:
+	tasklet_schedule(&dev->tasklet);
+}
+
+static int pn533_submit_urb_for_response(struct pn533 *dev, gfp_t flags)
+{
+	dev->in_urb->complete = pn533_recv_response;
+
+	return usb_submit_urb(dev->in_urb, flags);
+}
+
+static void pn533_recv_ack(struct urb *urb)
+{
+	struct pn533 *dev = urb->context;
+	struct pn533_frame *in_frame;
+	int rc;
+
+	switch (urb->status) {
+	case 0:
+		/* success */
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		nfc_dev_dbg(&dev->interface->dev, "Urb shutting down with"
+						" status: %d", urb->status);
+		dev->tklt_in_error = urb->status;
+		goto sched_tasklet;
+	default:
+		nfc_dev_err(&dev->interface->dev, "Nonzero urb status received:"
+							" %d", urb->status);
+		dev->tklt_in_error = urb->status;
+		goto sched_tasklet;
+	}
+
+	in_frame = dev->in_urb->transfer_buffer;
+
+	if (!pn533_rx_frame_is_ack(in_frame)) {
+		nfc_dev_err(&dev->interface->dev, "Received an invalid ack");
+		dev->tklt_in_error = -EIO;
+		goto sched_tasklet;
+	}
+
+	nfc_dev_dbg(&dev->interface->dev, "Received a valid ack");
+
+	rc = pn533_submit_urb_for_response(dev, GFP_ATOMIC);
+	if (rc) {
+		nfc_dev_err(&dev->interface->dev, "usb_submit_urb failed with"
+							" result %d", rc);
+		dev->tklt_in_error = rc;
+		goto sched_tasklet;
+	}
+
+	return;
+
+sched_tasklet:
+	dev->tklt_in_frame = NULL;
+	tasklet_schedule(&dev->tasklet);
+}
+
+static int pn533_submit_urb_for_ack(struct pn533 *dev, gfp_t flags)
+{
+	dev->in_urb->complete = pn533_recv_ack;
+
+	return usb_submit_urb(dev->in_urb, flags);
+}
+
+static int pn533_send_ack(struct pn533 *dev, gfp_t flags)
+{
+	int rc;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+	pn533_tx_frame_ack(dev->out_frame);
+
+	dev->out_urb->transfer_buffer = dev->out_frame;
+	dev->out_urb->transfer_buffer_length = PN533_FRAME_ACK_SIZE;
+	rc = usb_submit_urb(dev->out_urb, flags);
+
+	return rc;
+}
+
+static int __pn533_send_cmd_frame_async(struct pn533 *dev,
+					struct pn533_frame *out_frame,
+					struct pn533_frame *in_frame,
+					int in_frame_len,
+					pn533_cmd_complete_t cmd_complete,
+					void *arg, gfp_t flags)
+{
+	int rc;
+
+	nfc_dev_dbg(&dev->interface->dev, "Sending command 0x%x",
+						PN533_FRAME_CMD(out_frame));
+
+	dev->cmd = PN533_FRAME_CMD(out_frame);
+	dev->cmd_complete = cmd_complete;
+	dev->cmd_complete_arg = arg;
+
+	dev->out_urb->transfer_buffer = out_frame;
+	dev->out_urb->transfer_buffer_length =
+				PN533_FRAME_SIZE(out_frame);
+
+	dev->in_urb->transfer_buffer = in_frame;
+	dev->in_urb->transfer_buffer_length = in_frame_len;
+
+	rc = usb_submit_urb(dev->out_urb, flags);
+	if (rc)
+		return rc;
+
+	rc = pn533_submit_urb_for_ack(dev, flags);
+	if (rc)
+		goto error;
+
+	return 0;
+
+error:
+	usb_unlink_urb(dev->out_urb);
+	return rc;
+}
+
+static int pn533_send_cmd_frame_async(struct pn533 *dev,
+					struct pn533_frame *out_frame,
+					struct pn533_frame *in_frame,
+					int in_frame_len,
+					pn533_cmd_complete_t cmd_complete,
+					void *arg, gfp_t flags)
+{
+	int rc;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+	if (down_trylock(&dev->cmd_lock))
+		return -EBUSY;
+
+	rc = __pn533_send_cmd_frame_async(dev, out_frame, in_frame,
+					in_frame_len, cmd_complete, arg, flags);
+	if (rc)
+		goto error;
+
+	return 0;
+error:
+	up(&dev->cmd_lock);
+	return rc;
+}
+
+struct pn533_sync_cmd_response {
+	int rc;
+	struct completion done;
+};
+
+static int pn533_sync_cmd_complete(struct pn533 *dev, void *_arg,
+					u8 *params, int params_len)
+{
+	struct pn533_sync_cmd_response *arg = _arg;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+	arg->rc = 0;
+
+	if (params_len < 0) /* error */
+		arg->rc = params_len;
+
+	complete(&arg->done);
+
+	return 0;
+}
+
+static int pn533_send_cmd_frame_sync(struct pn533 *dev,
+						struct pn533_frame *out_frame,
+						struct pn533_frame *in_frame,
+						int in_frame_len)
+{
+	int rc;
+	struct pn533_sync_cmd_response arg;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+	init_completion(&arg.done);
+
+	rc = pn533_send_cmd_frame_async(dev, out_frame, in_frame, in_frame_len,
+				pn533_sync_cmd_complete, &arg, GFP_KERNEL);
+	if (rc)
+		return rc;
+
+	wait_for_completion(&arg.done);
+
+	return arg.rc;
+}
+
+static void pn533_send_complete(struct urb *urb)
+{
+	struct pn533 *dev = urb->context;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+	switch (urb->status) {
+	case 0:
+		/* success */
+		break;
+	case -ECONNRESET:
+	case -ENOENT:
+	case -ESHUTDOWN:
+		nfc_dev_dbg(&dev->interface->dev, "Urb shutting down with"
+						" status: %d", urb->status);
+		break;
+	default:
+		nfc_dev_dbg(&dev->interface->dev, "Nonzero urb status received:"
+							" %d", urb->status);
+	}
+}
+
+struct pn533_target_type_a {
+	__be16 sens_res;
+	u8 sel_res;
+	u8 nfcid_len;
+	u8 nfcid_data[];
+} __packed;
+
+
+#define PN533_TYPE_A_SENS_RES_NFCID1(x) ((u8)((be16_to_cpu(x) & 0x00C0) >> 6))
+#define PN533_TYPE_A_SENS_RES_SSD(x) ((u8)((be16_to_cpu(x) & 0x001F) >> 0))
+#define PN533_TYPE_A_SENS_RES_PLATCONF(x) ((u8)((be16_to_cpu(x) & 0x0F00) >> 8))
+
+#define PN533_TYPE_A_SENS_RES_SSD_JEWEL 0x00
+#define PN533_TYPE_A_SENS_RES_PLATCONF_JEWEL 0x0C
+
+#define PN533_TYPE_A_SEL_PROT(x) (((x) & 0x60) >> 5)
+#define PN533_TYPE_A_SEL_CASCADE(x) (((x) & 0x04) >> 2)
+
+#define PN533_TYPE_A_SEL_PROT_MIFARE 0
+#define PN533_TYPE_A_SEL_PROT_ISO14443 1
+#define PN533_TYPE_A_SEL_PROT_DEP 2
+#define PN533_TYPE_A_SEL_PROT_ISO14443_DEP 3
+
+static bool pn533_target_type_a_is_valid(struct pn533_target_type_a *type_a,
+							int target_data_len)
+{
+	u8 ssd;
+	u8 platconf;
+
+	if (target_data_len < sizeof(struct pn533_target_type_a))
+		return false;
+
+	/* The lenght check of nfcid[] and ats[] are not being performed because
+	   the values are not being used */
+
+	/* Requirement 4.6.3.3 from NFC Forum Digital Spec */
+	ssd = PN533_TYPE_A_SENS_RES_SSD(type_a->sens_res);
+	platconf = PN533_TYPE_A_SENS_RES_PLATCONF(type_a->sens_res);
+
+	if ((ssd == PN533_TYPE_A_SENS_RES_SSD_JEWEL &&
+			platconf != PN533_TYPE_A_SENS_RES_PLATCONF_JEWEL) ||
+			(ssd != PN533_TYPE_A_SENS_RES_SSD_JEWEL &&
+			platconf == PN533_TYPE_A_SENS_RES_PLATCONF_JEWEL))
+		return false;
+
+	/* Requirements 4.8.2.1, 4.8.2.3, 4.8.2.5 and 4.8.2.7 from NFC Forum */
+	if (PN533_TYPE_A_SEL_CASCADE(type_a->sel_res) != 0)
+		return false;
+
+	return true;
+}
+
+static int pn533_target_found_type_a(struct nfc_target *nfc_tgt, u8 *tgt_data,
+							int tgt_data_len)
+{
+	struct pn533_target_type_a *tgt_type_a;
+
+	tgt_type_a = (struct pn533_target_type_a *) tgt_data;
+
+	if (!pn533_target_type_a_is_valid(tgt_type_a, tgt_data_len))
+		return -EPROTO;
+
+	switch (PN533_TYPE_A_SEL_PROT(tgt_type_a->sel_res)) {
+	case PN533_TYPE_A_SEL_PROT_MIFARE:
+		nfc_tgt->supported_protocols = NFC_PROTO_MIFARE_MASK;
+		break;
+	case PN533_TYPE_A_SEL_PROT_ISO14443:
+		nfc_tgt->supported_protocols = NFC_PROTO_ISO14443_MASK;
+		break;
+	case PN533_TYPE_A_SEL_PROT_DEP:
+		nfc_tgt->supported_protocols = NFC_PROTO_NFC_DEP_MASK;
+		break;
+	case PN533_TYPE_A_SEL_PROT_ISO14443_DEP:
+		nfc_tgt->supported_protocols = NFC_PROTO_ISO14443_MASK |
+							NFC_PROTO_NFC_DEP_MASK;
+		break;
+	}
+
+	nfc_tgt->sens_res = be16_to_cpu(tgt_type_a->sens_res);
+	nfc_tgt->sel_res = tgt_type_a->sel_res;
+
+	return 0;
+}
+
+struct pn533_target_felica {
+	u8 pol_res;
+	u8 opcode;
+	u8 nfcid2[8];
+	u8 pad[8];
+	/* optional */
+	u8 syst_code[];
+} __packed;
+
+#define PN533_FELICA_SENSF_NFCID2_DEP_B1 0x01
+#define PN533_FELICA_SENSF_NFCID2_DEP_B2 0xFE
+
+static bool pn533_target_felica_is_valid(struct pn533_target_felica *felica,
+							int target_data_len)
+{
+	if (target_data_len < sizeof(struct pn533_target_felica))
+		return false;
+
+	if (felica->opcode != PN533_FELICA_OPC_SENSF_RES)
+		return false;
+
+	return true;
+}
+
+static int pn533_target_found_felica(struct nfc_target *nfc_tgt, u8 *tgt_data,
+							int tgt_data_len)
+{
+	struct pn533_target_felica *tgt_felica;
+
+	tgt_felica = (struct pn533_target_felica *) tgt_data;
+
+	if (!pn533_target_felica_is_valid(tgt_felica, tgt_data_len))
+		return -EPROTO;
+
+	if (tgt_felica->nfcid2[0] == PN533_FELICA_SENSF_NFCID2_DEP_B1 &&
+					tgt_felica->nfcid2[1] ==
+					PN533_FELICA_SENSF_NFCID2_DEP_B2)
+		nfc_tgt->supported_protocols = NFC_PROTO_NFC_DEP_MASK;
+	else
+		nfc_tgt->supported_protocols = NFC_PROTO_FELICA_MASK;
+
+	return 0;
+}
+
+struct pn533_target_jewel {
+	__be16 sens_res;
+	u8 jewelid[4];
+} __packed;
+
+static bool pn533_target_jewel_is_valid(struct pn533_target_jewel *jewel,
+							int target_data_len)
+{
+	u8 ssd;
+	u8 platconf;
+
+	if (target_data_len < sizeof(struct pn533_target_jewel))
+		return false;
+
+	/* Requirement 4.6.3.3 from NFC Forum Digital Spec */
+	ssd = PN533_TYPE_A_SENS_RES_SSD(jewel->sens_res);
+	platconf = PN533_TYPE_A_SENS_RES_PLATCONF(jewel->sens_res);
+
+	if ((ssd == PN533_TYPE_A_SENS_RES_SSD_JEWEL &&
+			platconf != PN533_TYPE_A_SENS_RES_PLATCONF_JEWEL) ||
+			(ssd != PN533_TYPE_A_SENS_RES_SSD_JEWEL &&
+			platconf == PN533_TYPE_A_SENS_RES_PLATCONF_JEWEL))
+		return false;
+
+	return true;
+}
+
+static int pn533_target_found_jewel(struct nfc_target *nfc_tgt, u8 *tgt_data,
+							int tgt_data_len)
+{
+	struct pn533_target_jewel *tgt_jewel;
+
+	tgt_jewel = (struct pn533_target_jewel *) tgt_data;
+
+	if (!pn533_target_jewel_is_valid(tgt_jewel, tgt_data_len))
+		return -EPROTO;
+
+	nfc_tgt->supported_protocols = NFC_PROTO_JEWEL_MASK;
+	nfc_tgt->sens_res = be16_to_cpu(tgt_jewel->sens_res);
+
+	return 0;
+}
+
+struct pn533_type_b_prot_info {
+	u8 bitrate;
+	u8 fsci_type;
+	u8 fwi_adc_fo;
+} __packed;
+
+#define PN533_TYPE_B_PROT_FCSI(x) (((x) & 0xF0) >> 4)
+#define PN533_TYPE_B_PROT_TYPE(x) (((x) & 0x0F) >> 0)
+#define PN533_TYPE_B_PROT_TYPE_RFU_MASK 0x8
+
+struct pn533_type_b_sens_res {
+	u8 opcode;
+	u8 nfcid[4];
+	u8 appdata[4];
+	struct pn533_type_b_prot_info prot_info;
+} __packed;
+
+#define PN533_TYPE_B_OPC_SENSB_RES 0x50
+
+struct pn533_target_type_b {
+	struct pn533_type_b_sens_res sensb_res;
+	u8 attrib_res_len;
+	u8 attrib_res[];
+} __packed;
+
+static bool pn533_target_type_b_is_valid(struct pn533_target_type_b *type_b,
+							int target_data_len)
+{
+	if (target_data_len < sizeof(struct pn533_target_type_b))
+		return false;
+
+	if (type_b->sensb_res.opcode != PN533_TYPE_B_OPC_SENSB_RES)
+		return false;
+
+	if (PN533_TYPE_B_PROT_TYPE(type_b->sensb_res.prot_info.fsci_type) &
+						PN533_TYPE_B_PROT_TYPE_RFU_MASK)
+		return false;
+
+	return true;
+}
+
+static int pn533_target_found_type_b(struct nfc_target *nfc_tgt, u8 *tgt_data,
+							int tgt_data_len)
+{
+	struct pn533_target_type_b *tgt_type_b;
+
+	tgt_type_b = (struct pn533_target_type_b *) tgt_data;
+
+	if (!pn533_target_type_b_is_valid(tgt_type_b, tgt_data_len))
+		return -EPROTO;
+
+	nfc_tgt->supported_protocols = NFC_PROTO_ISO14443_MASK;
+
+	return 0;
+}
+
+struct pn533_poll_response {
+	u8 nbtg;
+	u8 tg;
+	u8 target_data[];
+} __packed;
+
+static int pn533_target_found(struct pn533 *dev,
+			struct pn533_poll_response *resp, int resp_len)
+{
+	int target_data_len;
+	struct nfc_target nfc_tgt;
+	int rc;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s - modulation=%d", __func__,
+							dev->poll_mod_curr);
+
+	if (resp->tg != 1)
+		return -EPROTO;
+
+	target_data_len = resp_len - sizeof(struct pn533_poll_response);
+
+	switch (dev->poll_mod_curr) {
+	case PN533_POLL_MOD_106KBPS_A:
+		rc = pn533_target_found_type_a(&nfc_tgt, resp->target_data,
+							target_data_len);
+		break;
+	case PN533_POLL_MOD_212KBPS_FELICA:
+	case PN533_POLL_MOD_424KBPS_FELICA:
+		rc = pn533_target_found_felica(&nfc_tgt, resp->target_data,
+							target_data_len);
+		break;
+	case PN533_POLL_MOD_106KBPS_JEWEL:
+		rc = pn533_target_found_jewel(&nfc_tgt, resp->target_data,
+							target_data_len);
+		break;
+	case PN533_POLL_MOD_847KBPS_B:
+		rc = pn533_target_found_type_b(&nfc_tgt, resp->target_data,
+							target_data_len);
+		break;
+	default:
+		nfc_dev_err(&dev->interface->dev, "Unknown current poll"
+								" modulation");
+		return -EPROTO;
+	}
+
+	if (rc)
+		return rc;
+
+	if (!(nfc_tgt.supported_protocols & dev->poll_protocols)) {
+		nfc_dev_dbg(&dev->interface->dev, "The target found does not"
+						" have the desired protocol");
+		return -EAGAIN;
+	}
+
+	nfc_dev_dbg(&dev->interface->dev, "Target found - supported protocols: "
+					"0x%x", nfc_tgt.supported_protocols);
+
+	dev->tgt_available_prots = nfc_tgt.supported_protocols;
+
+	nfc_targets_found(dev->nfc_dev, &nfc_tgt, 1);
+
+	return 0;
+}
+
+static void pn533_poll_reset_mod_list(struct pn533 *dev)
+{
+	dev->poll_mod_count = 0;
+}
+
+static void pn533_poll_add_mod(struct pn533 *dev, u8 mod_index)
+{
+	dev->poll_mod_active[dev->poll_mod_count] =
+		(struct pn533_poll_modulations *) &poll_mod[mod_index];
+	dev->poll_mod_count++;
+}
+
+static void pn533_poll_create_mod_list(struct pn533 *dev, u32 protocols)
+{
+	pn533_poll_reset_mod_list(dev);
+
+	if (protocols & NFC_PROTO_MIFARE_MASK
+					|| protocols & NFC_PROTO_ISO14443_MASK
+					|| protocols & NFC_PROTO_NFC_DEP_MASK)
+		pn533_poll_add_mod(dev, PN533_POLL_MOD_106KBPS_A);
+
+	if (protocols & NFC_PROTO_FELICA_MASK
+					|| protocols & NFC_PROTO_NFC_DEP_MASK) {
+		pn533_poll_add_mod(dev, PN533_POLL_MOD_212KBPS_FELICA);
+		pn533_poll_add_mod(dev, PN533_POLL_MOD_424KBPS_FELICA);
+	}
+
+	if (protocols & NFC_PROTO_JEWEL_MASK)
+		pn533_poll_add_mod(dev, PN533_POLL_MOD_106KBPS_JEWEL);
+
+	if (protocols & NFC_PROTO_ISO14443_MASK)
+		pn533_poll_add_mod(dev, PN533_POLL_MOD_847KBPS_B);
+}
+
+static void pn533_start_poll_frame(struct pn533_frame *frame,
+					struct pn533_poll_modulations *mod)
+{
+
+	pn533_tx_frame_init(frame, PN533_CMD_IN_LIST_PASSIVE_TARGET);
+
+	memcpy(PN533_FRAME_CMD_PARAMS_PTR(frame), &mod->data, mod->len);
+	frame->datalen += mod->len;
+
+	pn533_tx_frame_finish(frame);
+}
+
+static int pn533_start_poll_complete(struct pn533 *dev, void *arg,
+						u8 *params, int params_len)
+{
+	struct pn533_poll_response *resp;
+	struct pn533_poll_modulations *next_mod;
+	int rc;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+	if (params_len == -ENOENT) {
+		nfc_dev_dbg(&dev->interface->dev, "Polling operation has been"
+								" stopped");
+		goto stop_poll;
+	}
+
+	if (params_len < 0) {
+		nfc_dev_err(&dev->interface->dev, "Error %d when running poll",
+								params_len);
+		goto stop_poll;
+	}
+
+	resp = (struct pn533_poll_response *) params;
+	if (resp->nbtg) {
+		rc = pn533_target_found(dev, resp, params_len);
+
+		/* We must stop the poll after a valid target found */
+		if (rc == 0)
+			goto stop_poll;
+
+		if (rc != -EAGAIN)
+			nfc_dev_err(&dev->interface->dev, "The target found is"
+					" not valid - continuing to poll");
+	}
+
+	dev->poll_mod_curr = (dev->poll_mod_curr + 1) % dev->poll_mod_count;
+
+	next_mod = dev->poll_mod_active[dev->poll_mod_curr];
+
+	nfc_dev_dbg(&dev->interface->dev, "Polling next modulation (0x%x)",
+							dev->poll_mod_curr);
+
+	pn533_start_poll_frame(dev->out_frame, next_mod);
+
+	/* Don't need to down the semaphore again */
+	rc = __pn533_send_cmd_frame_async(dev, dev->out_frame, dev->in_frame,
+				dev->in_maxlen, pn533_start_poll_complete,
+				NULL, GFP_ATOMIC);
+
+	if (rc == -EPERM) {
+		nfc_dev_dbg(&dev->interface->dev, "Cannot poll next modulation"
+					" because poll has been stopped");
+		goto stop_poll;
+	}
+
+	if (rc) {
+		nfc_dev_err(&dev->interface->dev, "Error %d when trying to poll"
+							" next modulation", rc);
+		goto stop_poll;
+	}
+
+	/* Inform caller function to do not up the semaphore */
+	return -EINPROGRESS;
+
+stop_poll:
+	pn533_poll_reset_mod_list(dev);
+	dev->poll_protocols = 0;
+	return 0;
+}
+
+static int pn533_start_poll(struct nfc_dev *nfc_dev, u32 protocols)
+{
+	struct pn533 *dev = nfc_get_drvdata(nfc_dev);
+	struct pn533_poll_modulations *start_mod;
+	int rc;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s - protocols=0x%x", __func__,
+								protocols);
+
+	if (dev->poll_mod_count) {
+		nfc_dev_err(&dev->interface->dev, "Polling operation already"
+								" active");
+		return -EBUSY;
+	}
+
+	if (dev->tgt_active_prot) {
+		nfc_dev_err(&dev->interface->dev, "Cannot poll with a target"
+							" already activated");
+		return -EBUSY;
+	}
+
+	pn533_poll_create_mod_list(dev, protocols);
+
+	if (!dev->poll_mod_count) {
+		nfc_dev_err(&dev->interface->dev, "No valid protocols"
+								" specified");
+		rc = -EINVAL;
+		goto error;
+	}
+
+	nfc_dev_dbg(&dev->interface->dev, "It will poll %d modulations types",
+							dev->poll_mod_count);
+
+	dev->poll_mod_curr = 0;
+	start_mod = dev->poll_mod_active[dev->poll_mod_curr];
+
+	pn533_start_poll_frame(dev->out_frame, start_mod);
+
+	rc = pn533_send_cmd_frame_async(dev, dev->out_frame, dev->in_frame,
+				dev->in_maxlen,	pn533_start_poll_complete,
+				NULL, GFP_KERNEL);
+
+	if (rc) {
+		nfc_dev_err(&dev->interface->dev, "Error %d when trying to"
+							" start poll", rc);
+		goto error;
+	}
+
+	dev->poll_protocols = protocols;
+
+	return 0;
+
+error:
+	pn533_poll_reset_mod_list(dev);
+	return rc;
+}
+
+static void pn533_stop_poll(struct nfc_dev *nfc_dev)
+{
+	struct pn533 *dev = nfc_get_drvdata(nfc_dev);
+
+	nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+	if (!dev->poll_mod_count) {
+		nfc_dev_dbg(&dev->interface->dev, "Polling operation was not"
+								" running");
+		return;
+	}
+
+	/* An ack will cancel the last issued command (poll) */
+	pn533_send_ack(dev, GFP_KERNEL);
+
+	/* prevent pn533_start_poll_complete to issue a new poll meanwhile */
+	usb_kill_urb(dev->in_urb);
+}
+
+static int pn533_activate_target_nfcdep(struct pn533 *dev)
+{
+	struct pn533_cmd_activate_param param;
+	struct pn533_cmd_activate_response *resp;
+	int rc;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+	pn533_tx_frame_init(dev->out_frame, PN533_CMD_IN_ATR);
+
+	param.tg = 1;
+	param.next = 0;
+	memcpy(PN533_FRAME_CMD_PARAMS_PTR(dev->out_frame), &param,
+				sizeof(struct pn533_cmd_activate_param));
+	dev->out_frame->datalen += sizeof(struct pn533_cmd_activate_param);
+
+	pn533_tx_frame_finish(dev->out_frame);
+
+	rc = pn533_send_cmd_frame_sync(dev, dev->out_frame, dev->in_frame,
+								dev->in_maxlen);
+	if (rc)
+		return rc;
+
+	resp = (struct pn533_cmd_activate_response *)
+				PN533_FRAME_CMD_PARAMS_PTR(dev->in_frame);
+	rc = resp->status & PN533_CMD_RET_MASK;
+	if (rc != PN533_CMD_RET_SUCCESS)
+		return -EIO;
+
+	return 0;
+}
+
+static int pn533_activate_target(struct nfc_dev *nfc_dev, u32 target_idx,
+								u32 protocol)
+{
+	struct pn533 *dev = nfc_get_drvdata(nfc_dev);
+	int rc;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s - protocol=%u", __func__,
+								protocol);
+
+	if (dev->poll_mod_count) {
+		nfc_dev_err(&dev->interface->dev, "Cannot activate while"
+								" polling");
+		return -EBUSY;
+	}
+
+	if (dev->tgt_active_prot) {
+		nfc_dev_err(&dev->interface->dev, "There is already an active"
+								" target");
+		return -EBUSY;
+	}
+
+	if (!dev->tgt_available_prots) {
+		nfc_dev_err(&dev->interface->dev, "There is no available target"
+								" to activate");
+		return -EINVAL;
+	}
+
+	if (!(dev->tgt_available_prots & (1 << protocol))) {
+		nfc_dev_err(&dev->interface->dev, "The target does not support"
+					" the requested protocol %u", protocol);
+		return -EINVAL;
+	}
+
+	if (protocol == NFC_PROTO_NFC_DEP) {
+		rc = pn533_activate_target_nfcdep(dev);
+		if (rc) {
+			nfc_dev_err(&dev->interface->dev, "Error %d when"
+						" activating target with"
+						" NFC_DEP protocol", rc);
+			return rc;
+		}
+	}
+
+	dev->tgt_active_prot = protocol;
+	dev->tgt_available_prots = 0;
+
+	return 0;
+}
+
+static void pn533_deactivate_target(struct nfc_dev *nfc_dev, u32 target_idx)
+{
+	struct pn533 *dev = nfc_get_drvdata(nfc_dev);
+	u8 tg;
+	u8 status;
+	int rc;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+	if (!dev->tgt_active_prot) {
+		nfc_dev_err(&dev->interface->dev, "There is no active target");
+		return;
+	}
+
+	dev->tgt_active_prot = 0;
+
+	pn533_tx_frame_init(dev->out_frame, PN533_CMD_IN_RELEASE);
+
+	tg = 1;
+	memcpy(PN533_FRAME_CMD_PARAMS_PTR(dev->out_frame), &tg, sizeof(u8));
+	dev->out_frame->datalen += sizeof(u8);
+
+	pn533_tx_frame_finish(dev->out_frame);
+
+	rc = pn533_send_cmd_frame_sync(dev, dev->out_frame, dev->in_frame,
+								dev->in_maxlen);
+	if (rc) {
+		nfc_dev_err(&dev->interface->dev, "Error when sending release"
+						" command to the controller");
+		return;
+	}
+
+	status = PN533_FRAME_CMD_PARAMS_PTR(dev->in_frame)[0];
+	rc = status & PN533_CMD_RET_MASK;
+	if (rc != PN533_CMD_RET_SUCCESS)
+		nfc_dev_err(&dev->interface->dev, "Error 0x%x when releasing"
+							" the target", rc);
+
+	return;
+}
+
+#define PN533_CMD_DATAEXCH_HEAD_LEN (sizeof(struct pn533_frame) + 3)
+#define PN533_CMD_DATAEXCH_DATA_MAXLEN 262
+
+static int pn533_data_exchange_tx_frame(struct pn533 *dev, struct sk_buff *skb)
+{
+	int payload_len = skb->len;
+	struct pn533_frame *out_frame;
+	struct sk_buff *discarded;
+	u8 tg;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s - Sending %d bytes", __func__,
+								payload_len);
+
+	if (payload_len > PN533_CMD_DATAEXCH_DATA_MAXLEN) {
+		/* TODO: Implement support to multi-part data exchange */
+		nfc_dev_err(&dev->interface->dev, "Data length greater than the"
+						" max allowed: %d",
+						PN533_CMD_DATAEXCH_DATA_MAXLEN);
+		return -ENOSYS;
+	}
+
+	/* Reserving header space */
+	if (skb_cow_head(skb, PN533_CMD_DATAEXCH_HEAD_LEN)) {
+		nfc_dev_err(&dev->interface->dev, "Error to add header data");
+		return -ENOMEM;
+	}
+
+	/* Reserving tail space, see pn533_tx_frame_finish */
+	if (skb_cow_data(skb, PN533_FRAME_TAIL_SIZE, &discarded) < 0) {
+		nfc_dev_err(&dev->interface->dev, "Error to add tail data");
+		return -ENOMEM;
+	}
+
+	skb_push(skb, PN533_CMD_DATAEXCH_HEAD_LEN);
+	out_frame = (struct pn533_frame *) skb->data;
+
+	pn533_tx_frame_init(out_frame, PN533_CMD_IN_DATA_EXCHANGE);
+
+	tg = 1;
+	memcpy(PN533_FRAME_CMD_PARAMS_PTR(out_frame), &tg, sizeof(u8));
+	out_frame->datalen += sizeof(u8);
+
+	/* The data is already in the out_frame, just update the datalen */
+	out_frame->datalen += payload_len;
+
+	pn533_tx_frame_finish(out_frame);
+	skb_put(skb, PN533_FRAME_TAIL_SIZE);
+
+	return 0;
+}
+
+struct pn533_data_exchange_arg {
+	struct sk_buff *skb_resp;
+	struct sk_buff *skb_out;
+	data_exchange_cb_t cb;
+	void *cb_context;
+};
+
+static int pn533_data_exchange_complete(struct pn533 *dev, void *_arg,
+						u8 *params, int params_len)
+{
+	struct pn533_data_exchange_arg *arg = _arg;
+	struct sk_buff *skb_resp = arg->skb_resp;
+	struct pn533_frame *in_frame = (struct pn533_frame *) skb_resp->data;
+	int err = 0;
+	u8 status;
+	u8 cmd_ret;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+	dev_kfree_skb_irq(arg->skb_out);
+
+	if (params_len < 0) { /* error */
+		err = params_len;
+		goto error;
+	}
+
+	skb_put(skb_resp, PN533_FRAME_SIZE(in_frame));
+
+	status = params[0];
+
+	cmd_ret = status & PN533_CMD_RET_MASK;
+	if (cmd_ret != PN533_CMD_RET_SUCCESS) {
+		nfc_dev_err(&dev->interface->dev, "PN533 reported error %d when"
+						" exchanging data", cmd_ret);
+		err = -EIO;
+		goto error;
+	}
+
+	if (status & PN533_CMD_MI_MASK) {
+		/* TODO: Implement support to multi-part data exchange */
+		nfc_dev_err(&dev->interface->dev, "Multi-part message not yet"
+								" supported");
+		/* Prevent the other messages from controller */
+		pn533_send_ack(dev, GFP_ATOMIC);
+		err = -ENOSYS;
+		goto error;
+	}
+
+	skb_pull(skb_resp, PN533_CMD_DATAEXCH_HEAD_LEN);
+	skb_trim(skb_resp, skb_resp->len - PN533_FRAME_TAIL_SIZE);
+
+	arg->cb(arg->cb_context, skb_resp, 0);
+	kfree(arg);
+	return 0;
+
+error:
+	dev_kfree_skb_irq(skb_resp);
+	arg->cb(arg->cb_context, NULL, err);
+	kfree(arg);
+	return 0;
+}
+
+int pn533_data_exchange(struct nfc_dev *nfc_dev, u32 target_idx,
+						struct sk_buff *skb,
+						data_exchange_cb_t cb,
+						void *cb_context)
+{
+	struct pn533 *dev = nfc_get_drvdata(nfc_dev);
+	struct pn533_frame *out_frame, *in_frame;
+	struct pn533_data_exchange_arg *arg;
+	struct sk_buff *skb_resp;
+	int skb_resp_len;
+	int rc;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+	if (!dev->tgt_active_prot) {
+		nfc_dev_err(&dev->interface->dev, "Cannot exchange data if"
+						" there is no active target");
+		rc = -EINVAL;
+		goto error;
+	}
+
+	rc = pn533_data_exchange_tx_frame(dev, skb);
+	if (rc)
+		goto error;
+
+	skb_resp_len = PN533_CMD_DATAEXCH_HEAD_LEN +
+			PN533_CMD_DATAEXCH_DATA_MAXLEN +
+			PN533_FRAME_TAIL_SIZE;
+
+	skb_resp = nfc_alloc_skb(skb_resp_len, GFP_KERNEL);
+	if (!skb_resp) {
+		rc = -ENOMEM;
+		goto error;
+	}
+
+	in_frame = (struct pn533_frame *) skb_resp->data;
+	out_frame = (struct pn533_frame *) skb->data;
+
+	arg = kmalloc(sizeof(struct pn533_data_exchange_arg), GFP_KERNEL);
+	if (!arg) {
+		rc = -ENOMEM;
+		goto free_skb_resp;
+	}
+
+	arg->skb_resp = skb_resp;
+	arg->skb_out = skb;
+	arg->cb = cb;
+	arg->cb_context = cb_context;
+
+	rc = pn533_send_cmd_frame_async(dev, out_frame, in_frame, skb_resp_len,
+					pn533_data_exchange_complete, arg,
+					GFP_KERNEL);
+	if (rc) {
+		nfc_dev_err(&dev->interface->dev, "Error %d when trying to"
+						" perform data_exchange", rc);
+		goto free_arg;
+	}
+
+	return 0;
+
+free_arg:
+	kfree(arg);
+free_skb_resp:
+	kfree_skb(skb_resp);
+error:
+	kfree_skb(skb);
+	return rc;
+}
+
+static int pn533_set_configuration(struct pn533 *dev, u8 cfgitem, u8 *cfgdata,
+								u8 cfgdata_len)
+{
+	int rc;
+	u8 *params;
+
+	nfc_dev_dbg(&dev->interface->dev, "%s", __func__);
+
+	pn533_tx_frame_init(dev->out_frame, PN533_CMD_RF_CONFIGURATION);
+
+	params = PN533_FRAME_CMD_PARAMS_PTR(dev->out_frame);
+	params[0] = cfgitem;
+	memcpy(&params[1], cfgdata, cfgdata_len);
+	dev->out_frame->datalen += (1 + cfgdata_len);
+
+	pn533_tx_frame_finish(dev->out_frame);
+
+	rc = pn533_send_cmd_frame_sync(dev, dev->out_frame, dev->in_frame,
+								dev->in_maxlen);
+
+	return rc;
+}
+
+struct nfc_ops pn533_nfc_ops = {
+	.start_poll = pn533_start_poll,
+	.stop_poll = pn533_stop_poll,
+	.activate_target = pn533_activate_target,
+	.deactivate_target = pn533_deactivate_target,
+	.data_exchange = pn533_data_exchange,
+};
+
+static int pn533_probe(struct usb_interface *interface,
+			const struct usb_device_id *id)
+{
+	struct pn533_fw_version *fw_ver;
+	struct pn533 *dev;
+	struct usb_host_interface *iface_desc;
+	struct usb_endpoint_descriptor *endpoint;
+	struct pn533_config_max_retries max_retries;
+	int in_endpoint = 0;
+	int out_endpoint = 0;
+	int rc = -ENOMEM;
+	int i;
+	u32 protocols;
+
+	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
+	if (!dev)
+		return -ENOMEM;
+
+	dev->udev = usb_get_dev(interface_to_usbdev(interface));
+	dev->interface = interface;
+	sema_init(&dev->cmd_lock, 1);
+
+	iface_desc = interface->cur_altsetting;
+	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
+		endpoint = &iface_desc->endpoint[i].desc;
+
+		if (!in_endpoint && usb_endpoint_is_bulk_in(endpoint)) {
+			dev->in_maxlen = le16_to_cpu(endpoint->wMaxPacketSize);
+			in_endpoint = endpoint->bEndpointAddress;
+		}
+
+		if (!out_endpoint && usb_endpoint_is_bulk_out(endpoint)) {
+			dev->out_maxlen =
+				le16_to_cpu(endpoint->wMaxPacketSize);
+			out_endpoint = endpoint->bEndpointAddress;
+		}
+	}
+
+	if (!in_endpoint || !out_endpoint) {
+		nfc_dev_err(&interface->dev, "Could not find bulk-in or"
+							" bulk-out endpoint");
+		rc = -ENODEV;
+		goto error;
+	}
+
+	dev->in_frame = kmalloc(dev->in_maxlen, GFP_KERNEL);
+	dev->in_urb = usb_alloc_urb(0, GFP_KERNEL);
+	dev->out_frame = kmalloc(dev->out_maxlen, GFP_KERNEL);
+	dev->out_urb = usb_alloc_urb(0, GFP_KERNEL);
+
+	if (!dev->in_frame || !dev->out_frame ||
+		!dev->in_urb || !dev->out_urb)
+		goto error;
+
+	usb_fill_bulk_urb(dev->in_urb, dev->udev,
+			usb_rcvbulkpipe(dev->udev, in_endpoint),
+			NULL, 0, NULL, dev);
+	usb_fill_bulk_urb(dev->out_urb, dev->udev,
+			usb_sndbulkpipe(dev->udev, out_endpoint),
+			NULL, 0,
+			pn533_send_complete, dev);
+
+	tasklet_init(&dev->tasklet, pn533_tasklet_cmd_complete, (ulong)dev);
+
+	usb_set_intfdata(interface, dev);
+
+	pn533_tx_frame_init(dev->out_frame, PN533_CMD_GET_FIRMWARE_VERSION);
+	pn533_tx_frame_finish(dev->out_frame);
+
+	rc = pn533_send_cmd_frame_sync(dev, dev->out_frame, dev->in_frame,
+								dev->in_maxlen);
+	if (rc)
+		goto kill_tasklet;
+
+	fw_ver = (struct pn533_fw_version *)
+				PN533_FRAME_CMD_PARAMS_PTR(dev->in_frame);
+	nfc_dev_info(&dev->interface->dev, "NXP PN533 firmware ver %d.%d now"
+					" attached", fw_ver->ver, fw_ver->rev);
+
+	protocols = NFC_PROTO_JEWEL_MASK
+			| NFC_PROTO_MIFARE_MASK | NFC_PROTO_FELICA_MASK
+			| NFC_PROTO_ISO14443_MASK
+			| NFC_PROTO_NFC_DEP_MASK;
+
+	dev->nfc_dev = nfc_allocate_device(&pn533_nfc_ops, protocols);
+	if (!dev->nfc_dev)
+		goto kill_tasklet;
+
+	nfc_set_parent_dev(dev->nfc_dev, &interface->dev);
+	nfc_set_drvdata(dev->nfc_dev, dev);
+
+	rc = nfc_register_device(dev->nfc_dev);
+	if (rc)
+		goto free_nfc_dev;
+
+	max_retries.mx_rty_atr = PN533_CONFIG_MAX_RETRIES_ENDLESS;
+	max_retries.mx_rty_psl = 2;
+	max_retries.mx_rty_passive_act = PN533_CONFIG_MAX_RETRIES_NO_RETRY;
+
+	rc = pn533_set_configuration(dev, PN533_CFGITEM_MAX_RETRIES,
+				(u8 *) &max_retries, sizeof(max_retries));
+
+	if (rc) {
+		nfc_dev_err(&dev->interface->dev, "Error on setting MAX_RETRIES"
+								" config");
+		goto free_nfc_dev;
+	}
+
+	return 0;
+
+free_nfc_dev:
+	nfc_free_device(dev->nfc_dev);
+kill_tasklet:
+	tasklet_kill(&dev->tasklet);
+error:
+	kfree(dev->in_frame);
+	usb_free_urb(dev->in_urb);
+	kfree(dev->out_frame);
+	usb_free_urb(dev->out_urb);
+	kfree(dev);
+	return rc;
+}
+
+static void pn533_disconnect(struct usb_interface *interface)
+{
+	struct pn533 *dev;
+
+	dev = usb_get_intfdata(interface);
+	usb_set_intfdata(interface, NULL);
+
+	nfc_unregister_device(dev->nfc_dev);
+	nfc_free_device(dev->nfc_dev);
+
+	usb_kill_urb(dev->in_urb);
+	usb_kill_urb(dev->out_urb);
+
+	tasklet_kill(&dev->tasklet);
+
+	kfree(dev->in_frame);
+	usb_free_urb(dev->in_urb);
+	kfree(dev->out_frame);
+	usb_free_urb(dev->out_urb);
+	kfree(dev);
+
+	nfc_dev_info(&dev->interface->dev, "NXP PN533 NFC device disconnected");
+}
+
+static struct usb_driver pn533_driver = {
+	.name =		"pn533",
+	.probe =	pn533_probe,
+	.disconnect =	pn533_disconnect,
+	.id_table =	pn533_table,
+};
+
+static int __init pn533_init(void)
+{
+	int rc;
+
+	rc = usb_register(&pn533_driver);
+	if (rc)
+		err("usb_register failed. Error number %d", rc);
+
+	return rc;
+}
+
+static void __exit pn533_exit(void)
+{
+	usb_deregister(&pn533_driver);
+}
+
+module_init(pn533_init);
+module_exit(pn533_exit);
+
+MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>,"
+			" Aloisio Almeida Jr <aloisio.almeida@openbossa.org>");
+MODULE_DESCRIPTION("PN533 usb driver ver " VERSION);
+MODULE_VERSION(VERSION);
+MODULE_LICENSE("GPL");