drivers/nfc/st21nfcb/i2c.c - kernel/msm-4.9 - Gitiles

 /*
  * I2C Link Layer for ST21NFCB NCI based Driver
  * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2, as published by the Free Software Foundation.
  *
  * 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, see <http://www.gnu.org/licenses/>.
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/gpio.h>
 #include <linux/of_irq.h>
 #include <linux/of_gpio.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
 #include <linux/nfc.h>
 #include <linux/platform_data/st21nfcb.h>

 #include "ndlc.h"

 #define DRIVER_DESC "NCI NFC driver for ST21NFCB"

 /* ndlc header */
 #define ST21NFCB_FRAME_HEADROOM	1
 #define ST21NFCB_FRAME_TAILROOM 0

 #define ST21NFCB_NCI_I2C_MIN_SIZE 4   /* PCB(1) + NCI Packet header(3) */
 #define ST21NFCB_NCI_I2C_MAX_SIZE 250 /* req 4.2.1 */

 #define ST21NFCB_NCI_I2C_DRIVER_NAME "st21nfcb_nci_i2c"

 static struct i2c_device_id st21nfcb_nci_i2c_id_table[] = {
 	{ST21NFCB_NCI_DRIVER_NAME, 0},
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, st21nfcb_nci_i2c_id_table);

 struct st21nfcb_i2c_phy {
 	struct i2c_client *i2c_dev;
 	struct llt_ndlc *ndlc;

 	unsigned int gpio_reset;
 	unsigned int irq_polarity;
 };

 #define I2C_DUMP_SKB(info, skb)					\
 do {								\
 	pr_debug("%s:\n", info);				\
 	print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET,	\
 		       16, 1, (skb)->data, (skb)->len, 0);	\
 } while (0)

 static int st21nfcb_nci_i2c_enable(void *phy_id)
 {
 	struct st21nfcb_i2c_phy *phy = phy_id;

 	gpio_set_value(phy->gpio_reset, 0);
 	usleep_range(10000, 15000);
 	gpio_set_value(phy->gpio_reset, 1);
 	usleep_range(80000, 85000);

 	return 0;
 }

 static void st21nfcb_nci_i2c_disable(void *phy_id)
 {
 	struct st21nfcb_i2c_phy *phy = phy_id;

 	/* reset chip in order to flush clf */
 	gpio_set_value(phy->gpio_reset, 0);
 	usleep_range(10000, 15000);
 	gpio_set_value(phy->gpio_reset, 1);
 }

 /*
  * Writing a frame must not return the number of written bytes.
  * It must return either zero for success, or <0 for error.
  * In addition, it must not alter the skb
  */
 static int st21nfcb_nci_i2c_write(void *phy_id, struct sk_buff *skb)
 {
 	int r = -1;
 	struct st21nfcb_i2c_phy *phy = phy_id;
 	struct i2c_client *client = phy->i2c_dev;

 	I2C_DUMP_SKB("st21nfcb_nci_i2c_write", skb);

 	if (phy->ndlc->hard_fault != 0)
 		return phy->ndlc->hard_fault;

 	r = i2c_master_send(client, skb->data, skb->len);
 	if (r < 0) {  /* Retry, chip was in standby */
 		usleep_range(1000, 4000);
 		r = i2c_master_send(client, skb->data, skb->len);
 	}

 	if (r >= 0) {
 		if (r != skb->len)
 			r = -EREMOTEIO;
 		else
 			r = 0;
 	}

 	return r;
 }

 /*
  * Reads an ndlc frame and returns it in a newly allocated sk_buff.
  * returns:
  * frame size : if received frame is complete (find ST21NFCB_SOF_EOF at
  * end of read)
  * -EAGAIN : if received frame is incomplete (not find ST21NFCB_SOF_EOF
  * at end of read)
  * -EREMOTEIO : i2c read error (fatal)
  * -EBADMSG : frame was incorrect and discarded
  * (value returned from st21nfcb_nci_i2c_repack)
  * -EIO : if no ST21NFCB_SOF_EOF is found after reaching
  * the read length end sequence
  */
 static int st21nfcb_nci_i2c_read(struct st21nfcb_i2c_phy *phy,
 				 struct sk_buff **skb)
 {
 	int r;
 	u8 len;
 	u8 buf[ST21NFCB_NCI_I2C_MAX_SIZE];
 	struct i2c_client *client = phy->i2c_dev;

 	r = i2c_master_recv(client, buf, ST21NFCB_NCI_I2C_MIN_SIZE);
 	if (r < 0) {  /* Retry, chip was in standby */
 		usleep_range(1000, 4000);
 		r = i2c_master_recv(client, buf, ST21NFCB_NCI_I2C_MIN_SIZE);
 	}

 	if (r != ST21NFCB_NCI_I2C_MIN_SIZE)
 		return -EREMOTEIO;

 	len = be16_to_cpu(*(__be16 *) (buf + 2));
 	if (len > ST21NFCB_NCI_I2C_MAX_SIZE) {
 		nfc_err(&client->dev, "invalid frame len\n");
 		return -EBADMSG;
 	}

 	*skb = alloc_skb(ST21NFCB_NCI_I2C_MIN_SIZE + len, GFP_KERNEL);
 	if (*skb == NULL)
 		return -ENOMEM;

 	skb_reserve(*skb, ST21NFCB_NCI_I2C_MIN_SIZE);
 	skb_put(*skb, ST21NFCB_NCI_I2C_MIN_SIZE);
 	memcpy((*skb)->data, buf, ST21NFCB_NCI_I2C_MIN_SIZE);

 	if (!len)
 		return 0;

 	r = i2c_master_recv(client, buf, len);
 	if (r != len) {
 		kfree_skb(*skb);
 		return -EREMOTEIO;
 	}

 	skb_put(*skb, len);
 	memcpy((*skb)->data + ST21NFCB_NCI_I2C_MIN_SIZE, buf, len);

 	I2C_DUMP_SKB("i2c frame read", *skb);

 	return 0;
 }

 /*
  * Reads an ndlc frame from the chip.
  *
  * On ST21NFCB, IRQ goes in idle state when read starts.
  */
 static irqreturn_t st21nfcb_nci_irq_thread_fn(int irq, void *phy_id)
 {
 	struct st21nfcb_i2c_phy *phy = phy_id;
 	struct i2c_client *client;
 	struct sk_buff *skb = NULL;
 	int r;

 	if (!phy || !phy->ndlc || irq != phy->i2c_dev->irq) {
 		WARN_ON_ONCE(1);
 		return IRQ_NONE;
 	}

 	client = phy->i2c_dev;
 	dev_dbg(&client->dev, "IRQ\n");

 	if (phy->ndlc->hard_fault)
 		return IRQ_HANDLED;

 	if (!phy->ndlc->powered) {
 		st21nfcb_nci_i2c_disable(phy);
 		return IRQ_HANDLED;
 	}

 	r = st21nfcb_nci_i2c_read(phy, &skb);
 	if (r == -EREMOTEIO || r == -ENOMEM || r == -EBADMSG)
 		return IRQ_HANDLED;

 	ndlc_recv(phy->ndlc, skb);

 	return IRQ_HANDLED;
 }

 static struct nfc_phy_ops i2c_phy_ops = {
 	.write = st21nfcb_nci_i2c_write,
 	.enable = st21nfcb_nci_i2c_enable,
 	.disable = st21nfcb_nci_i2c_disable,
 };

 #ifdef CONFIG_OF
 static int st21nfcb_nci_i2c_of_request_resources(struct i2c_client *client)
 {
 	struct st21nfcb_i2c_phy *phy = i2c_get_clientdata(client);
 	struct device_node *pp;
 	int gpio;
 	int r;

 	pp = client->dev.of_node;
 	if (!pp)
 		return -ENODEV;

 	/* Get GPIO from device tree */
 	gpio = of_get_named_gpio(pp, "reset-gpios", 0);
 	if (gpio < 0) {
 		nfc_err(&client->dev,
 			"Failed to retrieve reset-gpios from device tree\n");
 		return gpio;
 	}

 	/* GPIO request and configuration */
 	r = devm_gpio_request_one(&client->dev, gpio,
 				GPIOF_OUT_INIT_HIGH, "clf_reset");
 	if (r) {
 		nfc_err(&client->dev, "Failed to request reset pin\n");
 		return r;
 	}
 	phy->gpio_reset = gpio;

 	phy->irq_polarity = irq_get_trigger_type(client->irq);

 	return 0;
 }
 #else
 static int st21nfcb_nci_i2c_of_request_resources(struct i2c_client *client)
 {
 	return -ENODEV;
 }
 #endif

 static int st21nfcb_nci_i2c_request_resources(struct i2c_client *client)
 {
 	struct st21nfcb_nfc_platform_data *pdata;
 	struct st21nfcb_i2c_phy *phy = i2c_get_clientdata(client);
 	int r;

 	pdata = client->dev.platform_data;
 	if (pdata == NULL) {
 		nfc_err(&client->dev, "No platform data\n");
 		return -EINVAL;
 	}

 	/* store for later use */
 	phy->gpio_reset = pdata->gpio_reset;
 	phy->irq_polarity = pdata->irq_polarity;

 	r = devm_gpio_request_one(&client->dev,
 			phy->gpio_reset, GPIOF_OUT_INIT_HIGH, "clf_reset");
 	if (r) {
 		pr_err("%s : reset gpio_request failed\n", __FILE__);
 		return r;
 	}

 	return 0;
 }

 static int st21nfcb_nci_i2c_probe(struct i2c_client *client,
 				  const struct i2c_device_id *id)
 {
 	struct st21nfcb_i2c_phy *phy;
 	struct st21nfcb_nfc_platform_data *pdata;
 	int r;

 	dev_dbg(&client->dev, "%s\n", __func__);
 	dev_dbg(&client->dev, "IRQ: %d\n", client->irq);

 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 		nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
 		return -ENODEV;
 	}

 	phy = devm_kzalloc(&client->dev, sizeof(struct st21nfcb_i2c_phy),
 			   GFP_KERNEL);
 	if (!phy)
 		return -ENOMEM;

 	phy->i2c_dev = client;

 	i2c_set_clientdata(client, phy);

 	pdata = client->dev.platform_data;
 	if (!pdata && client->dev.of_node) {
 		r = st21nfcb_nci_i2c_of_request_resources(client);
 		if (r) {
 			nfc_err(&client->dev, "No platform data\n");
 			return r;
 		}
 	} else if (pdata) {
 		r = st21nfcb_nci_i2c_request_resources(client);
 		if (r) {
 			nfc_err(&client->dev,
 				"Cannot get platform resources\n");
 			return r;
 		}
 	} else {
 		nfc_err(&client->dev,
 			"st21nfcb platform resources not available\n");
 		return -ENODEV;
 	}

 	r = ndlc_probe(phy, &i2c_phy_ops, &client->dev,
 			ST21NFCB_FRAME_HEADROOM, ST21NFCB_FRAME_TAILROOM,
 			&phy->ndlc);
 	if (r < 0) {
 		nfc_err(&client->dev, "Unable to register ndlc layer\n");
 		return r;
 	}

 	r = devm_request_threaded_irq(&client->dev, client->irq, NULL,
 				st21nfcb_nci_irq_thread_fn,
 				phy->irq_polarity | IRQF_ONESHOT,
 				ST21NFCB_NCI_DRIVER_NAME, phy);
 	if (r < 0)
 		nfc_err(&client->dev, "Unable to register IRQ handler\n");

 	return r;
 }

 static int st21nfcb_nci_i2c_remove(struct i2c_client *client)
 {
 	struct st21nfcb_i2c_phy *phy = i2c_get_clientdata(client);

 	dev_dbg(&client->dev, "%s\n", __func__);

 	ndlc_remove(phy->ndlc);

 	return 0;
 }

 #ifdef CONFIG_OF
 static const struct of_device_id of_st21nfcb_i2c_match[] = {
 	{ .compatible = "st,st21nfcb-i2c", },
 	{ .compatible = "st,st21nfcb_i2c", },
 	{}
 };
 MODULE_DEVICE_TABLE(of, of_st21nfcb_i2c_match);
 #endif

 static struct i2c_driver st21nfcb_nci_i2c_driver = {
 	.driver = {
 		.owner = THIS_MODULE,
 		.name = ST21NFCB_NCI_I2C_DRIVER_NAME,
 		.of_match_table = of_match_ptr(of_st21nfcb_i2c_match),
 	},
 	.probe = st21nfcb_nci_i2c_probe,
 	.id_table = st21nfcb_nci_i2c_id_table,
 	.remove = st21nfcb_nci_i2c_remove,
 };

 module_i2c_driver(st21nfcb_nci_i2c_driver);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION(DRIVER_DESC);
	/*
	* I2C Link Layer for ST21NFCB NCI based Driver
	* Copyright (C) 2014 STMicroelectronics SAS. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms and conditions of the GNU General Public License,
	* version 2, as published by the Free Software Foundation.
	*
	* 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, see <http://www.gnu.org/licenses/>.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/module.h>
	#include <linux/i2c.h>
	#include <linux/gpio.h>
	#include <linux/of_irq.h>
	#include <linux/of_gpio.h>
	#include <linux/interrupt.h>
	#include <linux/delay.h>
	#include <linux/nfc.h>
	#include <linux/platform_data/st21nfcb.h>

	#include "ndlc.h"

	#define DRIVER_DESC "NCI NFC driver for ST21NFCB"

	/* ndlc header */
	#define ST21NFCB_FRAME_HEADROOM 1
	#define ST21NFCB_FRAME_TAILROOM 0

	#define ST21NFCB_NCI_I2C_MIN_SIZE 4 /* PCB(1) + NCI Packet header(3) */
	#define ST21NFCB_NCI_I2C_MAX_SIZE 250 /* req 4.2.1 */

	#define ST21NFCB_NCI_I2C_DRIVER_NAME "st21nfcb_nci_i2c"

	static struct i2c_device_id st21nfcb_nci_i2c_id_table[] = {
	{ST21NFCB_NCI_DRIVER_NAME, 0},
	{}
	};
	MODULE_DEVICE_TABLE(i2c, st21nfcb_nci_i2c_id_table);

	struct st21nfcb_i2c_phy {
	struct i2c_client *i2c_dev;
	struct llt_ndlc *ndlc;

	unsigned int gpio_reset;
	unsigned int irq_polarity;
	};

	#define I2C_DUMP_SKB(info, skb) \
	do { \
	pr_debug("%s:\n", info); \
	print_hex_dump(KERN_DEBUG, "i2c: ", DUMP_PREFIX_OFFSET, \
	16, 1, (skb)->data, (skb)->len, 0); \
	} while (0)

	static int st21nfcb_nci_i2c_enable(void *phy_id)
	{
	struct st21nfcb_i2c_phy *phy = phy_id;

	gpio_set_value(phy->gpio_reset, 0);
	usleep_range(10000, 15000);
	gpio_set_value(phy->gpio_reset, 1);
	usleep_range(80000, 85000);

	return 0;
	}

	static void st21nfcb_nci_i2c_disable(void *phy_id)
	{
	struct st21nfcb_i2c_phy *phy = phy_id;

	/* reset chip in order to flush clf */
	gpio_set_value(phy->gpio_reset, 0);
	usleep_range(10000, 15000);
	gpio_set_value(phy->gpio_reset, 1);
	}

	/*
	* Writing a frame must not return the number of written bytes.
	* It must return either zero for success, or <0 for error.
	* In addition, it must not alter the skb
	*/
	static int st21nfcb_nci_i2c_write(void phy_id, struct sk_buff skb)
	{
	int r = -1;
	struct st21nfcb_i2c_phy *phy = phy_id;
	struct i2c_client *client = phy->i2c_dev;

	I2C_DUMP_SKB("st21nfcb_nci_i2c_write", skb);

	if (phy->ndlc->hard_fault != 0)
	return phy->ndlc->hard_fault;

	r = i2c_master_send(client, skb->data, skb->len);
	if (r < 0) { /* Retry, chip was in standby */
	usleep_range(1000, 4000);
	r = i2c_master_send(client, skb->data, skb->len);
	}

	if (r >= 0) {
	if (r != skb->len)
	r = -EREMOTEIO;
	else
	r = 0;
	}

	return r;
	}

	/*
	* Reads an ndlc frame and returns it in a newly allocated sk_buff.
	* returns:
	* frame size : if received frame is complete (find ST21NFCB_SOF_EOF at
	* end of read)
	* -EAGAIN : if received frame is incomplete (not find ST21NFCB_SOF_EOF
	* at end of read)
	* -EREMOTEIO : i2c read error (fatal)
	* -EBADMSG : frame was incorrect and discarded
	* (value returned from st21nfcb_nci_i2c_repack)
	* -EIO : if no ST21NFCB_SOF_EOF is found after reaching
	* the read length end sequence
	*/
	static int st21nfcb_nci_i2c_read(struct st21nfcb_i2c_phy *phy,
	struct sk_buff **skb)
	{
	int r;
	u8 len;
	u8 buf[ST21NFCB_NCI_I2C_MAX_SIZE];
	struct i2c_client *client = phy->i2c_dev;

	r = i2c_master_recv(client, buf, ST21NFCB_NCI_I2C_MIN_SIZE);
	if (r < 0) { /* Retry, chip was in standby */
	usleep_range(1000, 4000);
	r = i2c_master_recv(client, buf, ST21NFCB_NCI_I2C_MIN_SIZE);
	}

	if (r != ST21NFCB_NCI_I2C_MIN_SIZE)
	return -EREMOTEIO;

	len = be16_to_cpu((__be16 ) (buf + 2));
	if (len > ST21NFCB_NCI_I2C_MAX_SIZE) {
	nfc_err(&client->dev, "invalid frame len\n");
	return -EBADMSG;
	}

	*skb = alloc_skb(ST21NFCB_NCI_I2C_MIN_SIZE + len, GFP_KERNEL);
	if (*skb == NULL)
	return -ENOMEM;

	skb_reserve(*skb, ST21NFCB_NCI_I2C_MIN_SIZE);
	skb_put(*skb, ST21NFCB_NCI_I2C_MIN_SIZE);
	memcpy((*skb)->data, buf, ST21NFCB_NCI_I2C_MIN_SIZE);

	if (!len)
	return 0;

	r = i2c_master_recv(client, buf, len);
	if (r != len) {
	kfree_skb(*skb);
	return -EREMOTEIO;
	}

	skb_put(*skb, len);
	memcpy((*skb)->data + ST21NFCB_NCI_I2C_MIN_SIZE, buf, len);

	I2C_DUMP_SKB("i2c frame read", *skb);

	return 0;
	}

	/*
	* Reads an ndlc frame from the chip.
	*
	* On ST21NFCB, IRQ goes in idle state when read starts.
	*/
	static irqreturn_t st21nfcb_nci_irq_thread_fn(int irq, void *phy_id)
	{
	struct st21nfcb_i2c_phy *phy = phy_id;
	struct i2c_client *client;
	struct sk_buff *skb = NULL;
	int r;

	if (!phy \|\| !phy->ndlc \|\| irq != phy->i2c_dev->irq) {
	WARN_ON_ONCE(1);
	return IRQ_NONE;
	}

	client = phy->i2c_dev;
	dev_dbg(&client->dev, "IRQ\n");

	if (phy->ndlc->hard_fault)
	return IRQ_HANDLED;

	if (!phy->ndlc->powered) {
	st21nfcb_nci_i2c_disable(phy);
	return IRQ_HANDLED;
	}

	r = st21nfcb_nci_i2c_read(phy, &skb);
	if (r == -EREMOTEIO \|\| r == -ENOMEM \|\| r == -EBADMSG)
	return IRQ_HANDLED;

	ndlc_recv(phy->ndlc, skb);

	return IRQ_HANDLED;
	}

	static struct nfc_phy_ops i2c_phy_ops = {
	.write = st21nfcb_nci_i2c_write,
	.enable = st21nfcb_nci_i2c_enable,
	.disable = st21nfcb_nci_i2c_disable,
	};

	#ifdef CONFIG_OF
	static int st21nfcb_nci_i2c_of_request_resources(struct i2c_client *client)
	{
	struct st21nfcb_i2c_phy *phy = i2c_get_clientdata(client);
	struct device_node *pp;
	int gpio;
	int r;

	pp = client->dev.of_node;
	if (!pp)
	return -ENODEV;

	/* Get GPIO from device tree */
	gpio = of_get_named_gpio(pp, "reset-gpios", 0);
	if (gpio < 0) {
	nfc_err(&client->dev,
	"Failed to retrieve reset-gpios from device tree\n");
	return gpio;
	}

	/* GPIO request and configuration */
	r = devm_gpio_request_one(&client->dev, gpio,
	GPIOF_OUT_INIT_HIGH, "clf_reset");
	if (r) {
	nfc_err(&client->dev, "Failed to request reset pin\n");
	return r;
	}
	phy->gpio_reset = gpio;

	phy->irq_polarity = irq_get_trigger_type(client->irq);

	return 0;
	}
	#else
	static int st21nfcb_nci_i2c_of_request_resources(struct i2c_client *client)
	{
	return -ENODEV;
	}
	#endif

	static int st21nfcb_nci_i2c_request_resources(struct i2c_client *client)
	{
	struct st21nfcb_nfc_platform_data *pdata;
	struct st21nfcb_i2c_phy *phy = i2c_get_clientdata(client);
	int r;

	pdata = client->dev.platform_data;
	if (pdata == NULL) {
	nfc_err(&client->dev, "No platform data\n");
	return -EINVAL;
	}

	/* store for later use */
	phy->gpio_reset = pdata->gpio_reset;
	phy->irq_polarity = pdata->irq_polarity;

	r = devm_gpio_request_one(&client->dev,
	phy->gpio_reset, GPIOF_OUT_INIT_HIGH, "clf_reset");
	if (r) {
	pr_err("%s : reset gpio_request failed\n", __FILE__);
	return r;
	}

	return 0;
	}

	static int st21nfcb_nci_i2c_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct st21nfcb_i2c_phy *phy;
	struct st21nfcb_nfc_platform_data *pdata;
	int r;

	dev_dbg(&client->dev, "%s\n", __func__);
	dev_dbg(&client->dev, "IRQ: %d\n", client->irq);

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
	nfc_err(&client->dev, "Need I2C_FUNC_I2C\n");
	return -ENODEV;
	}

	phy = devm_kzalloc(&client->dev, sizeof(struct st21nfcb_i2c_phy),
	GFP_KERNEL);
	if (!phy)
	return -ENOMEM;

	phy->i2c_dev = client;

	i2c_set_clientdata(client, phy);

	pdata = client->dev.platform_data;
	if (!pdata && client->dev.of_node) {
	r = st21nfcb_nci_i2c_of_request_resources(client);
	if (r) {
	nfc_err(&client->dev, "No platform data\n");
	return r;
	}
	} else if (pdata) {
	r = st21nfcb_nci_i2c_request_resources(client);
	if (r) {
	nfc_err(&client->dev,
	"Cannot get platform resources\n");
	return r;
	}
	} else {
	nfc_err(&client->dev,
	"st21nfcb platform resources not available\n");
	return -ENODEV;
	}

	r = ndlc_probe(phy, &i2c_phy_ops, &client->dev,
	ST21NFCB_FRAME_HEADROOM, ST21NFCB_FRAME_TAILROOM,
	&phy->ndlc);
	if (r < 0) {
	nfc_err(&client->dev, "Unable to register ndlc layer\n");
	return r;
	}

	r = devm_request_threaded_irq(&client->dev, client->irq, NULL,
	st21nfcb_nci_irq_thread_fn,
	phy->irq_polarity \| IRQF_ONESHOT,
	ST21NFCB_NCI_DRIVER_NAME, phy);
	if (r < 0)
	nfc_err(&client->dev, "Unable to register IRQ handler\n");

	return r;
	}

	static int st21nfcb_nci_i2c_remove(struct i2c_client *client)
	{
	struct st21nfcb_i2c_phy *phy = i2c_get_clientdata(client);

	dev_dbg(&client->dev, "%s\n", __func__);

	ndlc_remove(phy->ndlc);

	return 0;
	}

	#ifdef CONFIG_OF
	static const struct of_device_id of_st21nfcb_i2c_match[] = {
	{ .compatible = "st,st21nfcb-i2c", },
	{ .compatible = "st,st21nfcb_i2c", },
	{}
	};
	MODULE_DEVICE_TABLE(of, of_st21nfcb_i2c_match);
	#endif

	static struct i2c_driver st21nfcb_nci_i2c_driver = {
	.driver = {
	.owner = THIS_MODULE,
	.name = ST21NFCB_NCI_I2C_DRIVER_NAME,
	.of_match_table = of_match_ptr(of_st21nfcb_i2c_match),
	},
	.probe = st21nfcb_nci_i2c_probe,
	.id_table = st21nfcb_nci_i2c_id_table,
	.remove = st21nfcb_nci_i2c_remove,
	};

	module_i2c_driver(st21nfcb_nci_i2c_driver);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION(DRIVER_DESC);