drivers/nfc/pn544.c - kernel/tegra - Git at Google

 /*
  * Copyright (C) 2010 Trusted Logic S.A.
  *
  * 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  *
  */

 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/fs.h>
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/list.h>
 #include <linux/i2c.h>
 #include <linux/irq.h>
 #include <linux/jiffies.h>
 #include <linux/uaccess.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/platform_device.h>
 #include <linux/gpio.h>
 #include <linux/miscdevice.h>
 #include <linux/spinlock.h>
 #include <linux/nfc/pn544.h>

 #define MAX_BUFFER_SIZE	512

 struct pn544_dev	{
 	wait_queue_head_t	read_wq;
 	struct mutex		read_mutex;
 	struct mutex		shutdown_mutex;
 	struct i2c_client	*client;
 	struct miscdevice	pn544_device;
 	unsigned int 		ven_gpio;
 	unsigned int 		firm_gpio;
 	unsigned int		irq_gpio;
 	bool			irq_enabled;
 	spinlock_t		irq_enabled_lock;
 	bool			shutdown_complete;
 };

 static void pn544_disable_irq(struct pn544_dev *pn544_dev)
 {
 	unsigned long flags;

 	spin_lock_irqsave(&pn544_dev->irq_enabled_lock, flags);
 	if (pn544_dev->irq_enabled) {
 		disable_irq_nosync(pn544_dev->client->irq);
 		pn544_dev->irq_enabled = false;
 	}
 	spin_unlock_irqrestore(&pn544_dev->irq_enabled_lock, flags);
 }

 static irqreturn_t pn544_dev_irq_handler(int irq, void *dev_id)
 {
 	struct pn544_dev *pn544_dev = dev_id;

 	pn544_disable_irq(pn544_dev);

 	/* Wake up waiting readers */
 	wake_up(&pn544_dev->read_wq);

 	return IRQ_HANDLED;
 }

 static ssize_t pn544_dev_read(struct file *filp, char __user *buf,
 		size_t count, loff_t *offset)
 {
 	struct pn544_dev *pn544_dev = filp->private_data;
 	char tmp[MAX_BUFFER_SIZE];
 	int ret;

 	if (count > MAX_BUFFER_SIZE)
 		count = MAX_BUFFER_SIZE;

 	pr_debug("%s : reading %zu bytes.\n", __func__, count);

 	mutex_lock(&pn544_dev->read_mutex);

 	if (pn544_dev && (pn544_dev->shutdown_complete == true)) {
 		pr_info(" %s : discarding read as " \
 		"NFC in shutdown state\n", __func__);
 		mutex_unlock(&pn544_dev->read_mutex);
 		return -ENODEV;
 	}

 	if (!gpio_get_value(pn544_dev->irq_gpio)) {
 		if (filp->f_flags & O_NONBLOCK) {
 			ret = -EAGAIN;
 			goto fail;
 		}

 		pn544_dev->irq_enabled = true;
 		enable_irq(pn544_dev->client->irq);
 		ret = wait_event_interruptible(pn544_dev->read_wq,
 				gpio_get_value(pn544_dev->irq_gpio));

 		pn544_disable_irq(pn544_dev);

 		if (ret)
 			goto fail;

 	}

 	/* Read data */
 	mutex_lock(&pn544_dev->shutdown_mutex);
 	ret = i2c_master_recv(pn544_dev->client, tmp, count);
 	mutex_unlock(&pn544_dev->shutdown_mutex);

 	mutex_unlock(&pn544_dev->read_mutex);

 	/* pn544 seems to be slow in handling I2C read requests
 	 * so add 1ms delay after recv operation */
 	udelay(1000);

 	if (ret < 0) {
 		pr_err("%s: i2c_master_recv returned %d\n", __func__, ret);
 		return ret;
 	}
 	if (ret > count) {
 		pr_err("%s: received too many bytes from i2c (%d)\n",
 			__func__, ret);
 		return -EIO;
 	}
 	if (copy_to_user(buf, tmp, ret)) {
 		pr_warning("%s : failed to copy to user space\n", __func__);
 		return -EFAULT;
 	}
 	return ret;

 fail:
 	mutex_unlock(&pn544_dev->read_mutex);
 	return ret;
 }

 static ssize_t pn544_dev_write(struct file *filp, const char __user *buf,
 		size_t count, loff_t *offset)
 {
 	struct pn544_dev  *pn544_dev;
 	char tmp[MAX_BUFFER_SIZE];
 	int ret;

 	pn544_dev = filp->private_data;

 	if (count > MAX_BUFFER_SIZE)
 		count = MAX_BUFFER_SIZE;

 	if (copy_from_user(tmp, buf, count)) {
 		pr_err("%s : failed to copy from user space\n", __func__);
 		return -EFAULT;
 	}
 	mutex_lock(&pn544_dev->shutdown_mutex);
 	if (pn544_dev && (pn544_dev->shutdown_complete == true)) {
 		pr_info("%s : discarding write " \
 		"as NFC in shutdown state\n", __func__);
 		mutex_unlock(&pn544_dev->shutdown_mutex);
 		return -ENODEV;
 	}

 	pr_debug("%s : writing %zu bytes.\n", __func__, count);
 	/* Write data */
 	ret = i2c_master_send(pn544_dev->client, tmp, count);
 	if (ret != count) {
 		pr_err("%s : i2c_master_send returned %d\n", __func__, ret);
 		ret = -EIO;
 	}
 	mutex_unlock(&pn544_dev->shutdown_mutex);

 	/* pn544 seems to be slow in handling I2C write requests
 	 * so add 1ms delay after I2C send oparation */
 	udelay(1000);

 	return ret;
 }

 static int pn544_dev_open(struct inode *inode, struct file *filp)
 {
 	struct pn544_dev *pn544_dev = container_of(filp->private_data,
 						struct pn544_dev,
 						pn544_device);

 	filp->private_data = pn544_dev;

 	pr_debug("%s : %d,%d\n", __func__, imajor(inode), iminor(inode));

 	return 0;
 }

 static long  pn544_dev_ioctl(struct file *filp, unsigned int cmd,
 				unsigned long arg)
 {
 	struct pn544_dev *pn544_dev = filp->private_data;

 	switch (cmd) {
 	case PN544_SET_PWR:
 		if (arg == 2) {
 			/* power on with firmware download (requires hw reset)
 			 */
 			pr_info("%s power on with firmware\n", __func__);
 			gpio_set_value(pn544_dev->ven_gpio, 1);
 			msleep(20);
 			if (pn544_dev->firm_gpio)
 				gpio_set_value(pn544_dev->firm_gpio, 1);
 			msleep(20);
 			gpio_set_value(pn544_dev->ven_gpio, 0);
 			msleep(100);
 			gpio_set_value(pn544_dev->ven_gpio, 1);
 			msleep(20);
 		} else if (arg == 1) {
 			/* power on */
 			pr_info("%s power on\n", __func__);
 			if (pn544_dev->firm_gpio)
 				gpio_set_value(pn544_dev->firm_gpio, 0);
 			gpio_set_value(pn544_dev->ven_gpio, 1);
 			msleep(100);
 		} else  if (arg == 0) {
 			/* power off */
 			pr_info("%s power off\n", __func__);
 			if (pn544_dev->firm_gpio)
 				gpio_set_value(pn544_dev->firm_gpio, 0);
 			gpio_set_value(pn544_dev->ven_gpio, 0);
 			msleep(100);
 		} else {
 			pr_err("%s bad arg %lu\n", __func__, arg);
 			return -EINVAL;
 		}
 		break;
 	default:
 		pr_err("%s bad ioctl %u\n", __func__, cmd);
 		return -EINVAL;
 	}

 	return 0;
 }

 static const struct file_operations pn544_dev_fops = {
 	.owner	= THIS_MODULE,
 	.llseek	= no_llseek,
 	.read	= pn544_dev_read,
 	.write	= pn544_dev_write,
 	.open	= pn544_dev_open,
 	.unlocked_ioctl  = pn544_dev_ioctl,
 };

 static int pn544_probe(struct i2c_client *client,
 		const struct i2c_device_id *id)
 {
 	int ret;
 	struct pn544_i2c_platform_data *platform_data;
 	struct pn544_dev *pn544_dev;

 	platform_data = client->dev.platform_data;

 	if (platform_data == NULL) {
 		pr_err("%s : nfc probe fail\n", __func__);
 		return  -ENODEV;
 	}

 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 		pr_err("%s : need I2C_FUNC_I2C\n", __func__);
 		return  -ENODEV;
 	}

 	ret = gpio_request(platform_data->irq_gpio, "nfc_int");
 	if (ret)
 		return  -ENODEV;
 	ret = gpio_request(platform_data->ven_gpio, "nfc_ven");
 	if (ret)
 		goto err_ven;
 	if (platform_data->firm_gpio) {
 		ret = gpio_request(platform_data->firm_gpio, "nfc_firm");
 		if (ret)
 			goto err_firm;
 	}

 	pn544_dev = kzalloc(sizeof(*pn544_dev), GFP_KERNEL);
 	if (pn544_dev == NULL) {
 		dev_err(&client->dev,
 				"failed to allocate memory for module data\n");
 		ret = -ENOMEM;
 		goto err_exit;
 	}

 	pn544_dev->irq_gpio = platform_data->irq_gpio;
 	pn544_dev->ven_gpio  = platform_data->ven_gpio;
 	pn544_dev->firm_gpio  = platform_data->firm_gpio;
 	pn544_dev->client   = client;

 	ret = gpio_direction_input(pn544_dev->irq_gpio);
 	if (ret < 0) {
 		pr_err("%s :not able to set irq_gpio as input\n", __func__);
 		goto err_ven;
 	}
 	ret = gpio_direction_output(pn544_dev->ven_gpio, 0);
 	if (ret < 0) {
 		pr_err("%s : not able to set ven_gpio as output\n", __func__);
 		goto err_firm;
 	}
 	if (platform_data->firm_gpio) {
 		ret = gpio_direction_output(pn544_dev->firm_gpio, 0);
 		if (ret < 0) {
 			pr_err("%s : not able to set firm_gpio as output\n",
 				 __func__);
 			goto err_exit;
 		}
 	}

 	/* init mutex and queues */
 	init_waitqueue_head(&pn544_dev->read_wq);
 	mutex_init(&pn544_dev->read_mutex);
 	mutex_init(&pn544_dev->shutdown_mutex);
 	spin_lock_init(&pn544_dev->irq_enabled_lock);

 	pn544_dev->pn544_device.minor = MISC_DYNAMIC_MINOR;
 	pn544_dev->pn544_device.name = "pn544";
 	pn544_dev->pn544_device.fops = &pn544_dev_fops;

 	ret = misc_register(&pn544_dev->pn544_device);
 	if (ret) {
 		pr_err("%s : misc_register failed\n", __FILE__);
 		goto err_misc_register;
 	}

 	/* request irq.  the irq is set whenever the chip has data available
 	 * for reading.  it is cleared when all data has been read.
 	 */
 	pr_info("%s : requesting IRQ %d\n", __func__, client->irq);
 	pn544_dev->irq_enabled = true;
 	ret = request_irq(client->irq, pn544_dev_irq_handler,
 			  IRQF_TRIGGER_HIGH, client->name, pn544_dev);
 	if (ret) {
 		dev_err(&client->dev, "request_irq failed\n");
 		goto err_request_irq_failed;
 	}
 	pn544_disable_irq(pn544_dev);
 	i2c_set_clientdata(client, pn544_dev);

 	return 0;

 err_request_irq_failed:
 	misc_deregister(&pn544_dev->pn544_device);
 err_misc_register:
 	mutex_destroy(&pn544_dev->read_mutex);
 	mutex_destroy(&pn544_dev->shutdown_mutex);
 	kfree(pn544_dev);
 err_exit:
 	if (pn544_dev->firm_gpio)
 		gpio_free(platform_data->firm_gpio);
 err_firm:
 	gpio_free(platform_data->ven_gpio);
 err_ven:
 	gpio_free(platform_data->irq_gpio);
 	return ret;
 }

 static int pn544_remove(struct i2c_client *client)
 {
 	struct pn544_dev *pn544_dev;

 	pn544_dev = i2c_get_clientdata(client);
 	free_irq(client->irq, pn544_dev);
 	misc_deregister(&pn544_dev->pn544_device);
 	mutex_destroy(&pn544_dev->read_mutex);
 	mutex_destroy(&pn544_dev->shutdown_mutex);
 	gpio_free(pn544_dev->irq_gpio);
 	gpio_free(pn544_dev->ven_gpio);
 	if (pn544_dev->firm_gpio)
 		gpio_free(pn544_dev->firm_gpio);
 	kfree(pn544_dev);

 	return 0;
 }

 static void pn544_shutdown(struct i2c_client *client)
 {
 	struct pn544_dev *pn544_data = i2c_get_clientdata(client);
 	mutex_lock(&pn544_data->shutdown_mutex);
 	if (client->irq)
 		disable_irq(client->irq);
 	pn544_data->shutdown_complete = true;
 	mutex_unlock(&pn544_data->shutdown_mutex);
 }

 static const struct i2c_device_id pn544_id[] = {
 	{ "pn544", 0 },
 	{ }
 };

 static struct i2c_driver pn544_driver = {
 	.id_table	= pn544_id,
 	.probe		= pn544_probe,
 	.remove		= pn544_remove,
 	.shutdown	= pn544_shutdown,
 	.driver		= {
 		.owner	= THIS_MODULE,
 		.name	= "pn544",
 	},
 };

 /*
  * module load/unload record keeping
  */

 static int __init pn544_dev_init(void)
 {
 	pr_info("Loading pn544 driver\n");
 	return i2c_add_driver(&pn544_driver);
 }
 module_init(pn544_dev_init);

 static void __exit pn544_dev_exit(void)
 {
 	pr_info("Unloading pn544 driver\n");
 	i2c_del_driver(&pn544_driver);
 }
 module_exit(pn544_dev_exit);

 MODULE_AUTHOR("Sylvain Fonteneau");
 MODULE_DESCRIPTION("NFC PN544 driver");
 MODULE_LICENSE("GPL");
	/*
	* Copyright (C) 2010 Trusted Logic S.A.
	*
	* 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	*
	*/

	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/fs.h>
	#include <linux/slab.h>
	#include <linux/init.h>
	#include <linux/list.h>
	#include <linux/i2c.h>
	#include <linux/irq.h>
	#include <linux/jiffies.h>
	#include <linux/uaccess.h>
	#include <linux/delay.h>
	#include <linux/interrupt.h>
	#include <linux/io.h>
	#include <linux/platform_device.h>
	#include <linux/gpio.h>
	#include <linux/miscdevice.h>
	#include <linux/spinlock.h>
	#include <linux/nfc/pn544.h>

	#define MAX_BUFFER_SIZE 512

	struct pn544_dev {
	wait_queue_head_t read_wq;
	struct mutex read_mutex;
	struct mutex shutdown_mutex;
	struct i2c_client *client;
	struct miscdevice pn544_device;
	unsigned int ven_gpio;
	unsigned int firm_gpio;
	unsigned int irq_gpio;
	bool irq_enabled;
	spinlock_t irq_enabled_lock;
	bool shutdown_complete;
	};

	static void pn544_disable_irq(struct pn544_dev *pn544_dev)
	{
	unsigned long flags;

	spin_lock_irqsave(&pn544_dev->irq_enabled_lock, flags);
	if (pn544_dev->irq_enabled) {
	disable_irq_nosync(pn544_dev->client->irq);
	pn544_dev->irq_enabled = false;
	}
	spin_unlock_irqrestore(&pn544_dev->irq_enabled_lock, flags);
	}

	static irqreturn_t pn544_dev_irq_handler(int irq, void *dev_id)
	{
	struct pn544_dev *pn544_dev = dev_id;

	pn544_disable_irq(pn544_dev);

	/* Wake up waiting readers */
	wake_up(&pn544_dev->read_wq);

	return IRQ_HANDLED;
	}

	static ssize_t pn544_dev_read(struct file filp, char __user buf,
	size_t count, loff_t *offset)
	{
	struct pn544_dev *pn544_dev = filp->private_data;
	char tmp[MAX_BUFFER_SIZE];
	int ret;

	if (count > MAX_BUFFER_SIZE)
	count = MAX_BUFFER_SIZE;

	pr_debug("%s : reading %zu bytes.\n", __func__, count);

	mutex_lock(&pn544_dev->read_mutex);

	if (pn544_dev && (pn544_dev->shutdown_complete == true)) {
	pr_info(" %s : discarding read as " \
	"NFC in shutdown state\n", __func__);
	mutex_unlock(&pn544_dev->read_mutex);
	return -ENODEV;
	}

	if (!gpio_get_value(pn544_dev->irq_gpio)) {
	if (filp->f_flags & O_NONBLOCK) {
	ret = -EAGAIN;
	goto fail;
	}

	pn544_dev->irq_enabled = true;
	enable_irq(pn544_dev->client->irq);
	ret = wait_event_interruptible(pn544_dev->read_wq,
	gpio_get_value(pn544_dev->irq_gpio));

	pn544_disable_irq(pn544_dev);

	if (ret)
	goto fail;

	}

	/* Read data */
	mutex_lock(&pn544_dev->shutdown_mutex);
	ret = i2c_master_recv(pn544_dev->client, tmp, count);
	mutex_unlock(&pn544_dev->shutdown_mutex);

	mutex_unlock(&pn544_dev->read_mutex);

	/* pn544 seems to be slow in handling I2C read requests
	* so add 1ms delay after recv operation */
	udelay(1000);

	if (ret < 0) {
	pr_err("%s: i2c_master_recv returned %d\n", __func__, ret);
	return ret;
	}
	if (ret > count) {
	pr_err("%s: received too many bytes from i2c (%d)\n",
	__func__, ret);
	return -EIO;
	}
	if (copy_to_user(buf, tmp, ret)) {
	pr_warning("%s : failed to copy to user space\n", __func__);
	return -EFAULT;
	}
	return ret;

	fail:
	mutex_unlock(&pn544_dev->read_mutex);
	return ret;
	}

	static ssize_t pn544_dev_write(struct file filp, const char __user buf,
	size_t count, loff_t *offset)
	{
	struct pn544_dev *pn544_dev;
	char tmp[MAX_BUFFER_SIZE];
	int ret;

	pn544_dev = filp->private_data;

	if (count > MAX_BUFFER_SIZE)
	count = MAX_BUFFER_SIZE;

	if (copy_from_user(tmp, buf, count)) {
	pr_err("%s : failed to copy from user space\n", __func__);
	return -EFAULT;
	}
	mutex_lock(&pn544_dev->shutdown_mutex);
	if (pn544_dev && (pn544_dev->shutdown_complete == true)) {
	pr_info("%s : discarding write " \
	"as NFC in shutdown state\n", __func__);
	mutex_unlock(&pn544_dev->shutdown_mutex);
	return -ENODEV;
	}

	pr_debug("%s : writing %zu bytes.\n", __func__, count);
	/* Write data */
	ret = i2c_master_send(pn544_dev->client, tmp, count);
	if (ret != count) {
	pr_err("%s : i2c_master_send returned %d\n", __func__, ret);
	ret = -EIO;
	}
	mutex_unlock(&pn544_dev->shutdown_mutex);

	/* pn544 seems to be slow in handling I2C write requests
	* so add 1ms delay after I2C send oparation */
	udelay(1000);

	return ret;
	}

	static int pn544_dev_open(struct inode inode, struct file filp)
	{
	struct pn544_dev *pn544_dev = container_of(filp->private_data,
	struct pn544_dev,
	pn544_device);

	filp->private_data = pn544_dev;

	pr_debug("%s : %d,%d\n", __func__, imajor(inode), iminor(inode));

	return 0;
	}

	static long pn544_dev_ioctl(struct file *filp, unsigned int cmd,
	unsigned long arg)
	{
	struct pn544_dev *pn544_dev = filp->private_data;

	switch (cmd) {
	case PN544_SET_PWR:
	if (arg == 2) {
	/* power on with firmware download (requires hw reset)
	*/
	pr_info("%s power on with firmware\n", __func__);
	gpio_set_value(pn544_dev->ven_gpio, 1);
	msleep(20);
	if (pn544_dev->firm_gpio)
	gpio_set_value(pn544_dev->firm_gpio, 1);
	msleep(20);
	gpio_set_value(pn544_dev->ven_gpio, 0);
	msleep(100);
	gpio_set_value(pn544_dev->ven_gpio, 1);
	msleep(20);
	} else if (arg == 1) {
	/* power on */
	pr_info("%s power on\n", __func__);
	if (pn544_dev->firm_gpio)
	gpio_set_value(pn544_dev->firm_gpio, 0);
	gpio_set_value(pn544_dev->ven_gpio, 1);
	msleep(100);
	} else if (arg == 0) {
	/* power off */
	pr_info("%s power off\n", __func__);
	if (pn544_dev->firm_gpio)
	gpio_set_value(pn544_dev->firm_gpio, 0);
	gpio_set_value(pn544_dev->ven_gpio, 0);
	msleep(100);
	} else {
	pr_err("%s bad arg %lu\n", __func__, arg);
	return -EINVAL;
	}
	break;
	default:
	pr_err("%s bad ioctl %u\n", __func__, cmd);
	return -EINVAL;
	}

	return 0;
	}

	static const struct file_operations pn544_dev_fops = {
	.owner = THIS_MODULE,
	.llseek = no_llseek,
	.read = pn544_dev_read,
	.write = pn544_dev_write,
	.open = pn544_dev_open,
	.unlocked_ioctl = pn544_dev_ioctl,
	};

	static int pn544_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	int ret;
	struct pn544_i2c_platform_data *platform_data;
	struct pn544_dev *pn544_dev;

	platform_data = client->dev.platform_data;

	if (platform_data == NULL) {
	pr_err("%s : nfc probe fail\n", __func__);
	return -ENODEV;
	}

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
	pr_err("%s : need I2C_FUNC_I2C\n", __func__);
	return -ENODEV;
	}

	ret = gpio_request(platform_data->irq_gpio, "nfc_int");
	if (ret)
	return -ENODEV;
	ret = gpio_request(platform_data->ven_gpio, "nfc_ven");
	if (ret)
	goto err_ven;
	if (platform_data->firm_gpio) {
	ret = gpio_request(platform_data->firm_gpio, "nfc_firm");
	if (ret)
	goto err_firm;
	}

	pn544_dev = kzalloc(sizeof(*pn544_dev), GFP_KERNEL);
	if (pn544_dev == NULL) {
	dev_err(&client->dev,
	"failed to allocate memory for module data\n");
	ret = -ENOMEM;
	goto err_exit;
	}

	pn544_dev->irq_gpio = platform_data->irq_gpio;
	pn544_dev->ven_gpio = platform_data->ven_gpio;
	pn544_dev->firm_gpio = platform_data->firm_gpio;
	pn544_dev->client = client;

	ret = gpio_direction_input(pn544_dev->irq_gpio);
	if (ret < 0) {
	pr_err("%s :not able to set irq_gpio as input\n", __func__);
	goto err_ven;
	}
	ret = gpio_direction_output(pn544_dev->ven_gpio, 0);
	if (ret < 0) {
	pr_err("%s : not able to set ven_gpio as output\n", __func__);
	goto err_firm;
	}
	if (platform_data->firm_gpio) {
	ret = gpio_direction_output(pn544_dev->firm_gpio, 0);
	if (ret < 0) {
	pr_err("%s : not able to set firm_gpio as output\n",
	__func__);
	goto err_exit;
	}
	}

	/* init mutex and queues */
	init_waitqueue_head(&pn544_dev->read_wq);
	mutex_init(&pn544_dev->read_mutex);
	mutex_init(&pn544_dev->shutdown_mutex);
	spin_lock_init(&pn544_dev->irq_enabled_lock);

	pn544_dev->pn544_device.minor = MISC_DYNAMIC_MINOR;
	pn544_dev->pn544_device.name = "pn544";
	pn544_dev->pn544_device.fops = &pn544_dev_fops;

	ret = misc_register(&pn544_dev->pn544_device);
	if (ret) {
	pr_err("%s : misc_register failed\n", __FILE__);
	goto err_misc_register;
	}

	/* request irq. the irq is set whenever the chip has data available
	* for reading. it is cleared when all data has been read.
	*/
	pr_info("%s : requesting IRQ %d\n", __func__, client->irq);
	pn544_dev->irq_enabled = true;
	ret = request_irq(client->irq, pn544_dev_irq_handler,
	IRQF_TRIGGER_HIGH, client->name, pn544_dev);
	if (ret) {
	dev_err(&client->dev, "request_irq failed\n");
	goto err_request_irq_failed;
	}
	pn544_disable_irq(pn544_dev);
	i2c_set_clientdata(client, pn544_dev);

	return 0;

	err_request_irq_failed:
	misc_deregister(&pn544_dev->pn544_device);
	err_misc_register:
	mutex_destroy(&pn544_dev->read_mutex);
	mutex_destroy(&pn544_dev->shutdown_mutex);
	kfree(pn544_dev);
	err_exit:
	if (pn544_dev->firm_gpio)
	gpio_free(platform_data->firm_gpio);
	err_firm:
	gpio_free(platform_data->ven_gpio);
	err_ven:
	gpio_free(platform_data->irq_gpio);
	return ret;
	}

	static int pn544_remove(struct i2c_client *client)
	{
	struct pn544_dev *pn544_dev;

	pn544_dev = i2c_get_clientdata(client);
	free_irq(client->irq, pn544_dev);
	misc_deregister(&pn544_dev->pn544_device);
	mutex_destroy(&pn544_dev->read_mutex);
	mutex_destroy(&pn544_dev->shutdown_mutex);
	gpio_free(pn544_dev->irq_gpio);
	gpio_free(pn544_dev->ven_gpio);
	if (pn544_dev->firm_gpio)
	gpio_free(pn544_dev->firm_gpio);
	kfree(pn544_dev);

	return 0;
	}

	static void pn544_shutdown(struct i2c_client *client)
	{
	struct pn544_dev *pn544_data = i2c_get_clientdata(client);
	mutex_lock(&pn544_data->shutdown_mutex);
	if (client->irq)
	disable_irq(client->irq);
	pn544_data->shutdown_complete = true;
	mutex_unlock(&pn544_data->shutdown_mutex);
	}

	static const struct i2c_device_id pn544_id[] = {
	{ "pn544", 0 },
	{ }
	};

	static struct i2c_driver pn544_driver = {
	.id_table = pn544_id,
	.probe = pn544_probe,
	.remove = pn544_remove,
	.shutdown = pn544_shutdown,
	.driver = {
	.owner = THIS_MODULE,
	.name = "pn544",
	},
	};

	/*
	* module load/unload record keeping
	*/

	static int __init pn544_dev_init(void)
	{
	pr_info("Loading pn544 driver\n");
	return i2c_add_driver(&pn544_driver);
	}
	module_init(pn544_dev_init);

	static void __exit pn544_dev_exit(void)
	{
	pr_info("Unloading pn544 driver\n");
	i2c_del_driver(&pn544_driver);
	}
	module_exit(pn544_dev_exit);

	MODULE_AUTHOR("Sylvain Fonteneau");
	MODULE_DESCRIPTION("NFC PN544 driver");
	MODULE_LICENSE("GPL");