net/nfc/core.c - kernel/msm-4.9 - Gitiles

 /*
  * 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/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/slab.h>

 #include "nfc.h"

 #define VERSION "0.1"

 int nfc_devlist_generation;
 DEFINE_MUTEX(nfc_devlist_mutex);

 int nfc_printk(const char *level, const char *format, ...)
 {
 	struct va_format vaf;
 	va_list args;
 	int r;

 	va_start(args, format);

 	vaf.fmt = format;
 	vaf.va = &args;

 	r = printk("%sNFC: %pV\n", level, &vaf);

 	va_end(args);

 	return r;
 }
 EXPORT_SYMBOL(nfc_printk);

 /**
  * nfc_start_poll - start polling for nfc targets
  *
  * @dev: The nfc device that must start polling
  * @protocols: bitset of nfc protocols that must be used for polling
  *
  * The device remains polling for targets until a target is found or
  * the nfc_stop_poll function is called.
  */
 int nfc_start_poll(struct nfc_dev *dev, u32 protocols)
 {
 	int rc;

 	nfc_dbg("dev_name=%s protocols=0x%x", dev_name(&dev->dev), protocols);

 	if (!protocols)
 		return -EINVAL;

 	device_lock(&dev->dev);

 	if (!device_is_registered(&dev->dev)) {
 		rc = -ENODEV;
 		goto error;
 	}

 	if (dev->polling) {
 		rc = -EBUSY;
 		goto error;
 	}

 	rc = dev->ops->start_poll(dev, protocols);
 	if (!rc)
 		dev->polling = true;

 error:
 	device_unlock(&dev->dev);
 	return rc;
 }

 /**
  * nfc_stop_poll - stop polling for nfc targets
  *
  * @dev: The nfc device that must stop polling
  */
 int nfc_stop_poll(struct nfc_dev *dev)
 {
 	int rc = 0;

 	nfc_dbg("dev_name=%s", dev_name(&dev->dev));

 	device_lock(&dev->dev);

 	if (!device_is_registered(&dev->dev)) {
 		rc = -ENODEV;
 		goto error;
 	}

 	if (!dev->polling) {
 		rc = -EINVAL;
 		goto error;
 	}

 	dev->ops->stop_poll(dev);
 	dev->polling = false;

 error:
 	device_unlock(&dev->dev);
 	return rc;
 }

 /**
  * nfc_activate_target - prepare the target for data exchange
  *
  * @dev: The nfc device that found the target
  * @target_idx: index of the target that must be activated
  * @protocol: nfc protocol that will be used for data exchange
  */
 int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol)
 {
 	int rc;

 	nfc_dbg("dev_name=%s target_idx=%u protocol=%u", dev_name(&dev->dev),
 							target_idx, protocol);

 	device_lock(&dev->dev);

 	if (!device_is_registered(&dev->dev)) {
 		rc = -ENODEV;
 		goto error;
 	}

 	rc = dev->ops->activate_target(dev, target_idx, protocol);

 error:
 	device_unlock(&dev->dev);
 	return rc;
 }

 /**
  * nfc_deactivate_target - deactivate a nfc target
  *
  * @dev: The nfc device that found the target
  * @target_idx: index of the target that must be deactivated
  */
 int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx)
 {
 	int rc = 0;

 	nfc_dbg("dev_name=%s target_idx=%u", dev_name(&dev->dev), target_idx);

 	device_lock(&dev->dev);

 	if (!device_is_registered(&dev->dev)) {
 		rc = -ENODEV;
 		goto error;
 	}

 	dev->ops->deactivate_target(dev, target_idx);

 error:
 	device_unlock(&dev->dev);
 	return rc;
 }

 /**
  * nfc_data_exchange - transceive data
  *
  * @dev: The nfc device that found the target
  * @target_idx: index of the target
  * @skb: data to be sent
  * @cb: callback called when the response is received
  * @cb_context: parameter for the callback function
  *
  * The user must wait for the callback before calling this function again.
  */
 int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx,
 					struct sk_buff *skb,
 					data_exchange_cb_t cb,
 					void *cb_context)
 {
 	int rc;

 	nfc_dbg("dev_name=%s target_idx=%u skb->len=%u", dev_name(&dev->dev),
 							target_idx, skb->len);

 	device_lock(&dev->dev);

 	if (!device_is_registered(&dev->dev)) {
 		rc = -ENODEV;
 		kfree_skb(skb);
 		goto error;
 	}

 	rc = dev->ops->data_exchange(dev, target_idx, skb, cb, cb_context);

 error:
 	device_unlock(&dev->dev);
 	return rc;
 }

 /**
  * nfc_alloc_skb - allocate a skb for data exchange responses
  *
  * @size: size to allocate
  * @gfp: gfp flags
  */
 struct sk_buff *nfc_alloc_skb(unsigned int size, gfp_t gfp)
 {
 	struct sk_buff *skb;
 	unsigned int total_size;

 	total_size = size + 1;
 	skb = alloc_skb(total_size, gfp);

 	if (skb)
 		skb_reserve(skb, 1);

 	return skb;
 }
 EXPORT_SYMBOL(nfc_alloc_skb);

 /**
  * nfc_targets_found - inform that targets were found
  *
  * @dev: The nfc device that found the targets
  * @targets: array of nfc targets found
  * @ntargets: targets array size
  *
  * The device driver must call this function when one or many nfc targets
  * are found. After calling this function, the device driver must stop
  * polling for targets.
  */
 int nfc_targets_found(struct nfc_dev *dev, struct nfc_target *targets,
 							int n_targets)
 {
 	int i;

 	nfc_dbg("dev_name=%s n_targets=%d", dev_name(&dev->dev), n_targets);

 	dev->polling = false;

 	for (i = 0; i < n_targets; i++)
 		targets[i].idx = dev->target_idx++;

 	spin_lock_bh(&dev->targets_lock);

 	dev->targets_generation++;

 	kfree(dev->targets);
 	dev->targets = kmemdup(targets, n_targets * sizeof(struct nfc_target),
 								GFP_ATOMIC);

 	if (!dev->targets) {
 		dev->n_targets = 0;
 		spin_unlock_bh(&dev->targets_lock);
 		return -ENOMEM;
 	}

 	dev->n_targets = n_targets;
 	spin_unlock_bh(&dev->targets_lock);

 	nfc_genl_targets_found(dev);

 	return 0;
 }
 EXPORT_SYMBOL(nfc_targets_found);

 static void nfc_release(struct device *d)
 {
 	struct nfc_dev *dev = to_nfc_dev(d);

 	nfc_dbg("dev_name=%s", dev_name(&dev->dev));

 	nfc_genl_data_exit(&dev->genl_data);
 	kfree(dev->targets);
 	kfree(dev);
 }

 struct class nfc_class = {
 	.name = "nfc",
 	.dev_release = nfc_release,
 };
 EXPORT_SYMBOL(nfc_class);

 static int match_idx(struct device *d, void *data)
 {
 	struct nfc_dev *dev = to_nfc_dev(d);
 	unsigned *idx = data;

 	return dev->idx == *idx;
 }

 struct nfc_dev *nfc_get_device(unsigned idx)
 {
 	struct device *d;

 	d = class_find_device(&nfc_class, NULL, &idx, match_idx);
 	if (!d)
 		return NULL;

 	return to_nfc_dev(d);
 }

 /**
  * nfc_allocate_device - allocate a new nfc device
  *
  * @ops: device operations
  * @supported_protocols: NFC protocols supported by the device
  */
 struct nfc_dev *nfc_allocate_device(struct nfc_ops *ops,
 					u32 supported_protocols)
 {
 	static atomic_t dev_no = ATOMIC_INIT(0);
 	struct nfc_dev *dev;

 	if (!ops->start_poll || !ops->stop_poll || !ops->activate_target ||
 		!ops->deactivate_target || !ops->data_exchange)
 		return NULL;

 	if (!supported_protocols)
 		return NULL;

 	dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL);
 	if (!dev)
 		return NULL;

 	dev->dev.class = &nfc_class;
 	dev->idx = atomic_inc_return(&dev_no) - 1;
 	dev_set_name(&dev->dev, "nfc%d", dev->idx);
 	device_initialize(&dev->dev);

 	dev->ops = ops;
 	dev->supported_protocols = supported_protocols;

 	spin_lock_init(&dev->targets_lock);
 	nfc_genl_data_init(&dev->genl_data);

 	/* first generation must not be 0 */
 	dev->targets_generation = 1;

 	return dev;
 }
 EXPORT_SYMBOL(nfc_allocate_device);

 /**
  * nfc_register_device - register a nfc device in the nfc subsystem
  *
  * @dev: The nfc device to register
  */
 int nfc_register_device(struct nfc_dev *dev)
 {
 	int rc;

 	nfc_dbg("dev_name=%s", dev_name(&dev->dev));

 	mutex_lock(&nfc_devlist_mutex);
 	nfc_devlist_generation++;
 	rc = device_add(&dev->dev);
 	mutex_unlock(&nfc_devlist_mutex);

 	if (rc < 0)
 		return rc;

 	rc = nfc_genl_device_added(dev);
 	if (rc)
 		nfc_dbg("The userspace won't be notified that the device %s was"
 						" added", dev_name(&dev->dev));


 	return 0;
 }
 EXPORT_SYMBOL(nfc_register_device);

 /**
  * nfc_unregister_device - unregister a nfc device in the nfc subsystem
  *
  * @dev: The nfc device to unregister
  */
 void nfc_unregister_device(struct nfc_dev *dev)
 {
 	int rc;

 	nfc_dbg("dev_name=%s", dev_name(&dev->dev));

 	mutex_lock(&nfc_devlist_mutex);
 	nfc_devlist_generation++;

 	/* lock to avoid unregistering a device while an operation
 	   is in progress */
 	device_lock(&dev->dev);
 	device_del(&dev->dev);
 	device_unlock(&dev->dev);

 	mutex_unlock(&nfc_devlist_mutex);

 	rc = nfc_genl_device_removed(dev);
 	if (rc)
 		nfc_dbg("The userspace won't be notified that the device %s"
 					" was removed", dev_name(&dev->dev));

 }
 EXPORT_SYMBOL(nfc_unregister_device);

 static int __init nfc_init(void)
 {
 	int rc;

 	nfc_info("NFC Core ver %s", VERSION);

 	rc = class_register(&nfc_class);
 	if (rc)
 		return rc;

 	rc = nfc_genl_init();
 	if (rc)
 		goto err_genl;

 	/* the first generation must not be 0 */
 	nfc_devlist_generation = 1;

 	rc = rawsock_init();
 	if (rc)
 		goto err_rawsock;

 	rc = af_nfc_init();
 	if (rc)
 		goto err_af_nfc;

 	return 0;

 err_af_nfc:
 	rawsock_exit();
 err_rawsock:
 	nfc_genl_exit();
 err_genl:
 	class_unregister(&nfc_class);
 	return rc;
 }

 static void __exit nfc_exit(void)
 {
 	af_nfc_exit();
 	rawsock_exit();
 	nfc_genl_exit();
 	class_unregister(&nfc_class);
 }

 subsys_initcall(nfc_init);
 module_exit(nfc_exit);

 MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>");
 MODULE_DESCRIPTION("NFC Core ver " VERSION);
 MODULE_VERSION(VERSION);
 MODULE_LICENSE("GPL");
	/*
	* 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/init.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/slab.h>

	#include "nfc.h"

	#define VERSION "0.1"

	int nfc_devlist_generation;
	DEFINE_MUTEX(nfc_devlist_mutex);

	int nfc_printk(const char level, const char format, ...)
	{
	struct va_format vaf;
	va_list args;
	int r;

	va_start(args, format);

	vaf.fmt = format;
	vaf.va = &args;

	r = printk("%sNFC: %pV\n", level, &vaf);

	va_end(args);

	return r;
	}
	EXPORT_SYMBOL(nfc_printk);

	/**
	* nfc_start_poll - start polling for nfc targets
	*
	* @dev: The nfc device that must start polling
	* @protocols: bitset of nfc protocols that must be used for polling
	*
	* The device remains polling for targets until a target is found or
	* the nfc_stop_poll function is called.
	*/
	int nfc_start_poll(struct nfc_dev *dev, u32 protocols)
	{
	int rc;

	nfc_dbg("dev_name=%s protocols=0x%x", dev_name(&dev->dev), protocols);

	if (!protocols)
	return -EINVAL;

	device_lock(&dev->dev);

	if (!device_is_registered(&dev->dev)) {
	rc = -ENODEV;
	goto error;
	}

	if (dev->polling) {
	rc = -EBUSY;
	goto error;
	}

	rc = dev->ops->start_poll(dev, protocols);
	if (!rc)
	dev->polling = true;

	error:
	device_unlock(&dev->dev);
	return rc;
	}

	/**
	* nfc_stop_poll - stop polling for nfc targets
	*
	* @dev: The nfc device that must stop polling
	*/
	int nfc_stop_poll(struct nfc_dev *dev)
	{
	int rc = 0;

	nfc_dbg("dev_name=%s", dev_name(&dev->dev));

	device_lock(&dev->dev);

	if (!device_is_registered(&dev->dev)) {
	rc = -ENODEV;
	goto error;
	}

	if (!dev->polling) {
	rc = -EINVAL;
	goto error;
	}

	dev->ops->stop_poll(dev);
	dev->polling = false;

	error:
	device_unlock(&dev->dev);
	return rc;
	}

	/**
	* nfc_activate_target - prepare the target for data exchange
	*
	* @dev: The nfc device that found the target
	* @target_idx: index of the target that must be activated
	* @protocol: nfc protocol that will be used for data exchange
	*/
	int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol)
	{
	int rc;

	nfc_dbg("dev_name=%s target_idx=%u protocol=%u", dev_name(&dev->dev),
	target_idx, protocol);

	device_lock(&dev->dev);

	if (!device_is_registered(&dev->dev)) {
	rc = -ENODEV;
	goto error;
	}

	rc = dev->ops->activate_target(dev, target_idx, protocol);

	error:
	device_unlock(&dev->dev);
	return rc;
	}

	/**
	* nfc_deactivate_target - deactivate a nfc target
	*
	* @dev: The nfc device that found the target
	* @target_idx: index of the target that must be deactivated
	*/
	int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx)
	{
	int rc = 0;

	nfc_dbg("dev_name=%s target_idx=%u", dev_name(&dev->dev), target_idx);

	device_lock(&dev->dev);

	if (!device_is_registered(&dev->dev)) {
	rc = -ENODEV;
	goto error;
	}

	dev->ops->deactivate_target(dev, target_idx);

	error:
	device_unlock(&dev->dev);
	return rc;
	}

	/**
	* nfc_data_exchange - transceive data
	*
	* @dev: The nfc device that found the target
	* @target_idx: index of the target
	* @skb: data to be sent
	* @cb: callback called when the response is received
	* @cb_context: parameter for the callback function
	*
	* The user must wait for the callback before calling this function again.
	*/
	int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx,
	struct sk_buff *skb,
	data_exchange_cb_t cb,
	void *cb_context)
	{
	int rc;

	nfc_dbg("dev_name=%s target_idx=%u skb->len=%u", dev_name(&dev->dev),
	target_idx, skb->len);

	device_lock(&dev->dev);

	if (!device_is_registered(&dev->dev)) {
	rc = -ENODEV;
	kfree_skb(skb);
	goto error;
	}

	rc = dev->ops->data_exchange(dev, target_idx, skb, cb, cb_context);

	error:
	device_unlock(&dev->dev);
	return rc;
	}

	/**
	* nfc_alloc_skb - allocate a skb for data exchange responses
	*
	* @size: size to allocate
	* @gfp: gfp flags
	*/
	struct sk_buff *nfc_alloc_skb(unsigned int size, gfp_t gfp)
	{
	struct sk_buff *skb;
	unsigned int total_size;

	total_size = size + 1;
	skb = alloc_skb(total_size, gfp);

	if (skb)
	skb_reserve(skb, 1);

	return skb;
	}
	EXPORT_SYMBOL(nfc_alloc_skb);

	/**
	* nfc_targets_found - inform that targets were found
	*
	* @dev: The nfc device that found the targets
	* @targets: array of nfc targets found
	* @ntargets: targets array size
	*
	* The device driver must call this function when one or many nfc targets
	* are found. After calling this function, the device driver must stop
	* polling for targets.
	*/
	int nfc_targets_found(struct nfc_dev dev, struct nfc_target targets,
	int n_targets)
	{
	int i;

	nfc_dbg("dev_name=%s n_targets=%d", dev_name(&dev->dev), n_targets);

	dev->polling = false;

	for (i = 0; i < n_targets; i++)
	targets[i].idx = dev->target_idx++;

	spin_lock_bh(&dev->targets_lock);

	dev->targets_generation++;

	kfree(dev->targets);
	dev->targets = kmemdup(targets, n_targets * sizeof(struct nfc_target),
	GFP_ATOMIC);

	if (!dev->targets) {
	dev->n_targets = 0;
	spin_unlock_bh(&dev->targets_lock);
	return -ENOMEM;
	}

	dev->n_targets = n_targets;
	spin_unlock_bh(&dev->targets_lock);

	nfc_genl_targets_found(dev);

	return 0;
	}
	EXPORT_SYMBOL(nfc_targets_found);

	static void nfc_release(struct device *d)
	{
	struct nfc_dev *dev = to_nfc_dev(d);

	nfc_dbg("dev_name=%s", dev_name(&dev->dev));

	nfc_genl_data_exit(&dev->genl_data);
	kfree(dev->targets);
	kfree(dev);
	}

	struct class nfc_class = {
	.name = "nfc",
	.dev_release = nfc_release,
	};
	EXPORT_SYMBOL(nfc_class);

	static int match_idx(struct device d, void data)
	{
	struct nfc_dev *dev = to_nfc_dev(d);
	unsigned *idx = data;

	return dev->idx == *idx;
	}

	struct nfc_dev *nfc_get_device(unsigned idx)
	{
	struct device *d;

	d = class_find_device(&nfc_class, NULL, &idx, match_idx);
	if (!d)
	return NULL;

	return to_nfc_dev(d);
	}

	/**
	* nfc_allocate_device - allocate a new nfc device
	*
	* @ops: device operations
	* @supported_protocols: NFC protocols supported by the device
	*/
	struct nfc_dev nfc_allocate_device(struct nfc_ops ops,
	u32 supported_protocols)
	{
	static atomic_t dev_no = ATOMIC_INIT(0);
	struct nfc_dev *dev;

	if (!ops->start_poll \|\| !ops->stop_poll \|\| !ops->activate_target \|\|
	!ops->deactivate_target \|\| !ops->data_exchange)
	return NULL;

	if (!supported_protocols)
	return NULL;

	dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL);
	if (!dev)
	return NULL;

	dev->dev.class = &nfc_class;
	dev->idx = atomic_inc_return(&dev_no) - 1;
	dev_set_name(&dev->dev, "nfc%d", dev->idx);
	device_initialize(&dev->dev);

	dev->ops = ops;
	dev->supported_protocols = supported_protocols;

	spin_lock_init(&dev->targets_lock);
	nfc_genl_data_init(&dev->genl_data);

	/* first generation must not be 0 */
	dev->targets_generation = 1;

	return dev;
	}
	EXPORT_SYMBOL(nfc_allocate_device);

	/**
	* nfc_register_device - register a nfc device in the nfc subsystem
	*
	* @dev: The nfc device to register
	*/
	int nfc_register_device(struct nfc_dev *dev)
	{
	int rc;

	nfc_dbg("dev_name=%s", dev_name(&dev->dev));

	mutex_lock(&nfc_devlist_mutex);
	nfc_devlist_generation++;
	rc = device_add(&dev->dev);
	mutex_unlock(&nfc_devlist_mutex);

	if (rc < 0)
	return rc;

	rc = nfc_genl_device_added(dev);
	if (rc)
	nfc_dbg("The userspace won't be notified that the device %s was"
	" added", dev_name(&dev->dev));


	return 0;
	}
	EXPORT_SYMBOL(nfc_register_device);

	/**
	* nfc_unregister_device - unregister a nfc device in the nfc subsystem
	*
	* @dev: The nfc device to unregister
	*/
	void nfc_unregister_device(struct nfc_dev *dev)
	{
	int rc;

	nfc_dbg("dev_name=%s", dev_name(&dev->dev));

	mutex_lock(&nfc_devlist_mutex);
	nfc_devlist_generation++;

	/* lock to avoid unregistering a device while an operation
	is in progress */
	device_lock(&dev->dev);
	device_del(&dev->dev);
	device_unlock(&dev->dev);

	mutex_unlock(&nfc_devlist_mutex);

	rc = nfc_genl_device_removed(dev);
	if (rc)
	nfc_dbg("The userspace won't be notified that the device %s"
	" was removed", dev_name(&dev->dev));

	}
	EXPORT_SYMBOL(nfc_unregister_device);

	static int __init nfc_init(void)
	{
	int rc;

	nfc_info("NFC Core ver %s", VERSION);

	rc = class_register(&nfc_class);
	if (rc)
	return rc;

	rc = nfc_genl_init();
	if (rc)
	goto err_genl;

	/* the first generation must not be 0 */
	nfc_devlist_generation = 1;

	rc = rawsock_init();
	if (rc)
	goto err_rawsock;

	rc = af_nfc_init();
	if (rc)
	goto err_af_nfc;

	return 0;

	err_af_nfc:
	rawsock_exit();
	err_rawsock:
	nfc_genl_exit();
	err_genl:
	class_unregister(&nfc_class);
	return rc;
	}

	static void __exit nfc_exit(void)
	{
	af_nfc_exit();
	rawsock_exit();
	nfc_genl_exit();
	class_unregister(&nfc_class);
	}

	subsys_initcall(nfc_init);
	module_exit(nfc_exit);

	MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>");
	MODULE_DESCRIPTION("NFC Core ver " VERSION);
	MODULE_VERSION(VERSION);
	MODULE_LICENSE("GPL");