[deliverable/linux.git] / net / nfc / core.c

/*
 * 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#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);

/**
 * nfc_dev_up - turn on the NFC device
 *
 * @dev: The nfc device to be turned on
 *
 * The device remains up until the nfc_dev_down function is called.
 */
int nfc_dev_up(struct nfc_dev *dev)
{
	int rc = 0;

	pr_debug("dev_name=%s\n", dev_name(&dev->dev));

	device_lock(&dev->dev);

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

	if (dev->dev_up) {
		rc = -EALREADY;
		goto error;
	}

	if (dev->ops->dev_up)
		rc = dev->ops->dev_up(dev);

	if (!rc)
		dev->dev_up = true;

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

/**
 * nfc_dev_down - turn off the NFC device
 *
 * @dev: The nfc device to be turned off
 */
int nfc_dev_down(struct nfc_dev *dev)
{
	int rc = 0;

	pr_debug("dev_name=%s\n", dev_name(&dev->dev));

	device_lock(&dev->dev);

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

	if (!dev->dev_up) {
		rc = -EALREADY;
		goto error;
	}

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

	if (dev->ops->dev_down)
		dev->ops->dev_down(dev);

	dev->dev_up = false;

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

/**
 * 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;

	pr_debug("dev_name=%s protocols=0x%x\n",
		 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;

	pr_debug("dev_name=%s\n", 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;

	pr_debug("dev_name=%s target_idx=%u protocol=%u\n",
		 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);
	if (!rc)
		dev->remote_activated = true;

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;

	pr_debug("dev_name=%s target_idx=%u\n",
		 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);
	dev->remote_activated = false;

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;

	pr_debug("dev_name=%s target_idx=%u skb->len=%u\n",
		 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;

	pr_debug("dev_name=%s n_targets=%d\n", 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);

	pr_debug("dev_name=%s\n", 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,
					int tx_headroom,
					int tx_tailroom)
{
	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;
	dev->tx_headroom = tx_headroom;
	dev->tx_tailroom = tx_tailroom;

	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;

	pr_debug("dev_name=%s\n", 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)
		pr_debug("The userspace won't be notified that the device %s was added\n",
			 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;

	pr_debug("dev_name=%s\n", 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)
		pr_debug("The userspace won't be notified that the device %s was removed\n",
			 dev_name(&dev->dev));

}
EXPORT_SYMBOL(nfc_unregister_device);

static int __init nfc_init(void)
{
	int rc;

	pr_info("NFC Core ver %s\n", 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");
Commit	Line	Data
3e256b8f LRV	1	/*
	2	* Copyright (C) 2011 Instituto Nokia de Tecnologia
	3	*
	4	* Authors:
	5	* Lauro Ramos Venancio <lauro.venancio@openbossa.org>
	6	* Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
	12	*
	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
	17	*
	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the
	20	* Free Software Foundation, Inc.,
	21	* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	22	*/
	23
ed1e0ad8 JP	24	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
ed1e0ad8 JP	25
3e256b8f LRV	26	#include <linux/init.h>
	27	#include <linux/kernel.h>
	28	#include <linux/module.h>
	29	#include <linux/slab.h>
	30
	31	#include "nfc.h"
	32
	33	#define VERSION "0.1"
	34
	35	int nfc_devlist_generation;
	36	DEFINE_MUTEX(nfc_devlist_mutex);
	37
8b3fe7b5 IE	38	/**
	39	* nfc_dev_up - turn on the NFC device
	40	*
	41	* @dev: The nfc device to be turned on
	42	*
	43	* The device remains up until the nfc_dev_down function is called.
	44	*/
	45	int nfc_dev_up(struct nfc_dev *dev)
	46	{
	47	int rc = 0;
	48
20c239c1	49	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
8b3fe7b5 IE	50
	51	device_lock(&dev->dev);
	52
	53	if (!device_is_registered(&dev->dev)) {
	54	rc = -ENODEV;
	55	goto error;
	56	}
	57
	58	if (dev->dev_up) {
	59	rc = -EALREADY;
	60	goto error;
	61	}
	62
	63	if (dev->ops->dev_up)
	64	rc = dev->ops->dev_up(dev);
	65
	66	if (!rc)
	67	dev->dev_up = true;
	68
	69	error:
	70	device_unlock(&dev->dev);
	71	return rc;
	72	}
	73
	74	/**
	75	* nfc_dev_down - turn off the NFC device
	76	*
	77	* @dev: The nfc device to be turned off
	78	*/
	79	int nfc_dev_down(struct nfc_dev *dev)
	80	{
	81	int rc = 0;
	82
20c239c1	83	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
8b3fe7b5 IE	84
	85	device_lock(&dev->dev);
	86
	87	if (!device_is_registered(&dev->dev)) {
	88	rc = -ENODEV;
	89	goto error;
	90	}
	91
	92	if (!dev->dev_up) {
	93	rc = -EALREADY;
	94	goto error;
	95	}
	96
	97	if (dev->polling \|\| dev->remote_activated) {
	98	rc = -EBUSY;
	99	goto error;
	100	}
	101
	102	if (dev->ops->dev_down)
	103	dev->ops->dev_down(dev);
	104
	105	dev->dev_up = false;
	106
	107	error:
	108	device_unlock(&dev->dev);
	109	return rc;
	110	}
	111
3e256b8f LRV	112	/**
	113	* nfc_start_poll - start polling for nfc targets
	114	*
	115	* @dev: The nfc device that must start polling
	116	* @protocols: bitset of nfc protocols that must be used for polling
	117	*
	118	* The device remains polling for targets until a target is found or
	119	* the nfc_stop_poll function is called.
	120	*/
	121	int nfc_start_poll(struct nfc_dev *dev, u32 protocols)
	122	{
	123	int rc;
	124
20c239c1 JP	125	pr_debug("dev_name=%s protocols=0x%x\n",
20c239c1 JP	126	dev_name(&dev->dev), protocols);
3e256b8f LRV	127
	128	if (!protocols)
	129	return -EINVAL;
	130
	131	device_lock(&dev->dev);
	132
	133	if (!device_is_registered(&dev->dev)) {
	134	rc = -ENODEV;
	135	goto error;
	136	}
	137
	138	if (dev->polling) {
	139	rc = -EBUSY;
	140	goto error;
	141	}
	142
	143	rc = dev->ops->start_poll(dev, protocols);
	144	if (!rc)
	145	dev->polling = true;
	146
	147	error:
	148	device_unlock(&dev->dev);
	149	return rc;
	150	}
	151
	152	/**
	153	* nfc_stop_poll - stop polling for nfc targets
	154	*
	155	* @dev: The nfc device that must stop polling
	156	*/
	157	int nfc_stop_poll(struct nfc_dev *dev)
	158	{
	159	int rc = 0;
	160
20c239c1	161	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
3e256b8f LRV	162
	163	device_lock(&dev->dev);
	164
	165	if (!device_is_registered(&dev->dev)) {
	166	rc = -ENODEV;
	167	goto error;
	168	}
	169
	170	if (!dev->polling) {
	171	rc = -EINVAL;
	172	goto error;
	173	}
	174
	175	dev->ops->stop_poll(dev);
	176	dev->polling = false;
	177
	178	error:
	179	device_unlock(&dev->dev);
	180	return rc;
	181	}
	182
	183	/**
	184	* nfc_activate_target - prepare the target for data exchange
	185	*
	186	* @dev: The nfc device that found the target
	187	* @target_idx: index of the target that must be activated
	188	* @protocol: nfc protocol that will be used for data exchange
	189	*/
	190	int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol)
	191	{
	192	int rc;
	193
20c239c1 JP	194	pr_debug("dev_name=%s target_idx=%u protocol=%u\n",
20c239c1 JP	195	dev_name(&dev->dev), target_idx, protocol);
3e256b8f LRV	196
	197	device_lock(&dev->dev);
	198
	199	if (!device_is_registered(&dev->dev)) {
	200	rc = -ENODEV;
	201	goto error;
	202	}
	203
	204	rc = dev->ops->activate_target(dev, target_idx, protocol);
8b3fe7b5 IE	205	if (!rc)
8b3fe7b5 IE	206	dev->remote_activated = true;
3e256b8f LRV	207
	208	error:
	209	device_unlock(&dev->dev);
	210	return rc;
	211	}
	212
	213	/**
	214	* nfc_deactivate_target - deactivate a nfc target
	215	*
	216	* @dev: The nfc device that found the target
	217	* @target_idx: index of the target that must be deactivated
	218	*/
	219	int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx)
	220	{
	221	int rc = 0;
	222
20c239c1 JP	223	pr_debug("dev_name=%s target_idx=%u\n",
20c239c1 JP	224	dev_name(&dev->dev), target_idx);
3e256b8f LRV	225
	226	device_lock(&dev->dev);
	227
	228	if (!device_is_registered(&dev->dev)) {
	229	rc = -ENODEV;
	230	goto error;
	231	}
	232
	233	dev->ops->deactivate_target(dev, target_idx);
8b3fe7b5	234	dev->remote_activated = false;
3e256b8f LRV	235
	236	error:
	237	device_unlock(&dev->dev);
	238	return rc;
	239	}
	240
	241	/**
	242	* nfc_data_exchange - transceive data
	243	*
	244	* @dev: The nfc device that found the target
	245	* @target_idx: index of the target
	246	* @skb: data to be sent
	247	* @cb: callback called when the response is received
	248	* @cb_context: parameter for the callback function
	249	*
	250	* The user must wait for the callback before calling this function again.
	251	*/
	252	int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx,
	253	struct sk_buff *skb,
	254	data_exchange_cb_t cb,
	255	void *cb_context)
	256	{
	257	int rc;
	258
20c239c1 JP	259	pr_debug("dev_name=%s target_idx=%u skb->len=%u\n",
20c239c1 JP	260	dev_name(&dev->dev), target_idx, skb->len);
3e256b8f LRV	261
	262	device_lock(&dev->dev);
	263
	264	if (!device_is_registered(&dev->dev)) {
	265	rc = -ENODEV;
	266	kfree_skb(skb);
	267	goto error;
	268	}
	269
	270	rc = dev->ops->data_exchange(dev, target_idx, skb, cb, cb_context);
	271
	272	error:
	273	device_unlock(&dev->dev);
	274	return rc;
	275	}
	276
	277	/**
	278	* nfc_alloc_skb - allocate a skb for data exchange responses
	279	*
	280	* @size: size to allocate
	281	* @gfp: gfp flags
	282	*/
	283	struct sk_buff *nfc_alloc_skb(unsigned int size, gfp_t gfp)
	284	{
	285	struct sk_buff *skb;
	286	unsigned int total_size;
	287
	288	total_size = size + 1;
	289	skb = alloc_skb(total_size, gfp);
	290
	291	if (skb)
	292	skb_reserve(skb, 1);
	293
	294	return skb;
	295	}
	296	EXPORT_SYMBOL(nfc_alloc_skb);
	297
4d12b8b1 LRV	298	/**
	299	* nfc_targets_found - inform that targets were found
	300	*
	301	* @dev: The nfc device that found the targets
	302	* @targets: array of nfc targets found
	303	* @ntargets: targets array size
	304	*
	305	* The device driver must call this function when one or many nfc targets
	306	* are found. After calling this function, the device driver must stop
	307	* polling for targets.
	308	*/
	309	int nfc_targets_found(struct nfc_dev dev, struct nfc_target targets,
	310	int n_targets)
	311	{
	312	int i;
	313
20c239c1	314	pr_debug("dev_name=%s n_targets=%d\n", dev_name(&dev->dev), n_targets);
4d12b8b1 LRV	315
	316	dev->polling = false;
	317
	318	for (i = 0; i < n_targets; i++)
	319	targets[i].idx = dev->target_idx++;
	320
	321	spin_lock_bh(&dev->targets_lock);
	322
	323	dev->targets_generation++;
	324
	325	kfree(dev->targets);
	326	dev->targets = kmemdup(targets, n_targets * sizeof(struct nfc_target),
	327	GFP_ATOMIC);
	328
	329	if (!dev->targets) {
	330	dev->n_targets = 0;
	331	spin_unlock_bh(&dev->targets_lock);
	332	return -ENOMEM;
	333	}
	334
	335	dev->n_targets = n_targets;
	336	spin_unlock_bh(&dev->targets_lock);
	337
	338	nfc_genl_targets_found(dev);
	339
	340	return 0;
	341	}
	342	EXPORT_SYMBOL(nfc_targets_found);
	343
3e256b8f LRV	344	static void nfc_release(struct device *d)
	345	{
	346	struct nfc_dev *dev = to_nfc_dev(d);
	347
20c239c1	348	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
3e256b8f	349
4d12b8b1 LRV	350	nfc_genl_data_exit(&dev->genl_data);
4d12b8b1 LRV	351	kfree(dev->targets);
3e256b8f LRV	352	kfree(dev);
	353	}
	354
	355	struct class nfc_class = {
	356	.name = "nfc",
	357	.dev_release = nfc_release,
	358	};
	359	EXPORT_SYMBOL(nfc_class);
	360
	361	static int match_idx(struct device d, void data)
	362	{
	363	struct nfc_dev *dev = to_nfc_dev(d);
	364	unsigned *idx = data;
	365
	366	return dev->idx == *idx;
	367	}
	368
	369	struct nfc_dev *nfc_get_device(unsigned idx)
	370	{
	371	struct device *d;
	372
	373	d = class_find_device(&nfc_class, NULL, &idx, match_idx);
	374	if (!d)
	375	return NULL;
	376
	377	return to_nfc_dev(d);
	378	}
	379
	380	/**
	381	* nfc_allocate_device - allocate a new nfc device
	382	*
	383	* @ops: device operations
	384	* @supported_protocols: NFC protocols supported by the device
	385	*/
	386	struct nfc_dev nfc_allocate_device(struct nfc_ops ops,
e8753043 SO	387	u32 supported_protocols,
	388	int tx_headroom,
	389	int tx_tailroom)
3e256b8f LRV	390	{
	391	static atomic_t dev_no = ATOMIC_INIT(0);
	392	struct nfc_dev *dev;
	393
	394	if (!ops->start_poll \|\| !ops->stop_poll \|\| !ops->activate_target \|\|
	395	!ops->deactivate_target \|\| !ops->data_exchange)
	396	return NULL;
	397
	398	if (!supported_protocols)
	399	return NULL;
	400
	401	dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL);
	402	if (!dev)
	403	return NULL;
	404
	405	dev->dev.class = &nfc_class;
	406	dev->idx = atomic_inc_return(&dev_no) - 1;
	407	dev_set_name(&dev->dev, "nfc%d", dev->idx);
	408	device_initialize(&dev->dev);
	409
	410	dev->ops = ops;
	411	dev->supported_protocols = supported_protocols;
e8753043 SO	412	dev->tx_headroom = tx_headroom;
e8753043 SO	413	dev->tx_tailroom = tx_tailroom;
3e256b8f	414
4d12b8b1 LRV	415	spin_lock_init(&dev->targets_lock);
	416	nfc_genl_data_init(&dev->genl_data);
	417
	418	/* first generation must not be 0 */
	419	dev->targets_generation = 1;
	420
3e256b8f LRV	421	return dev;
	422	}
	423	EXPORT_SYMBOL(nfc_allocate_device);
	424
	425	/**
	426	* nfc_register_device - register a nfc device in the nfc subsystem
	427	*
	428	* @dev: The nfc device to register
	429	*/
	430	int nfc_register_device(struct nfc_dev *dev)
	431	{
	432	int rc;
	433
20c239c1	434	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
3e256b8f LRV	435
	436	mutex_lock(&nfc_devlist_mutex);
	437	nfc_devlist_generation++;
	438	rc = device_add(&dev->dev);
	439	mutex_unlock(&nfc_devlist_mutex);
	440
4d12b8b1 LRV	441	if (rc < 0)
	442	return rc;
	443
	444	rc = nfc_genl_device_added(dev);
	445	if (rc)
20c239c1 JP	446	pr_debug("The userspace won't be notified that the device %s was added\n",
20c239c1 JP	447	dev_name(&dev->dev));
4d12b8b1 LRV	448
4d12b8b1 LRV	449	return 0;
3e256b8f LRV	450	}
	451	EXPORT_SYMBOL(nfc_register_device);
	452
	453	/**
	454	* nfc_unregister_device - unregister a nfc device in the nfc subsystem
	455	*
	456	* @dev: The nfc device to unregister
	457	*/
	458	void nfc_unregister_device(struct nfc_dev *dev)
	459	{
4d12b8b1 LRV	460	int rc;
4d12b8b1 LRV	461
20c239c1	462	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
3e256b8f LRV	463
	464	mutex_lock(&nfc_devlist_mutex);
	465	nfc_devlist_generation++;
	466
	467	/* lock to avoid unregistering a device while an operation
	468	is in progress */
	469	device_lock(&dev->dev);
	470	device_del(&dev->dev);
	471	device_unlock(&dev->dev);
	472
	473	mutex_unlock(&nfc_devlist_mutex);
4d12b8b1 LRV	474
	475	rc = nfc_genl_device_removed(dev);
	476	if (rc)
20c239c1 JP	477	pr_debug("The userspace won't be notified that the device %s was removed\n",
20c239c1 JP	478	dev_name(&dev->dev));
4d12b8b1	479
3e256b8f LRV	480	}
	481	EXPORT_SYMBOL(nfc_unregister_device);
	482
	483	static int __init nfc_init(void)
	484	{
4d12b8b1 LRV	485	int rc;
4d12b8b1 LRV	486
ed1e0ad8	487	pr_info("NFC Core ver %s\n", VERSION);
3e256b8f	488
4d12b8b1 LRV	489	rc = class_register(&nfc_class);
	490	if (rc)
	491	return rc;
	492
	493	rc = nfc_genl_init();
	494	if (rc)
	495	goto err_genl;
	496
	497	/* the first generation must not be 0 */
	498	nfc_devlist_generation = 1;
	499
23b7869c LRV	500	rc = rawsock_init();
	501	if (rc)
	502	goto err_rawsock;
	503
c7fe3b52 AAJ	504	rc = af_nfc_init();
	505	if (rc)
	506	goto err_af_nfc;
	507
4d12b8b1 LRV	508	return 0;
4d12b8b1 LRV	509
c7fe3b52	510	err_af_nfc:
23b7869c LRV	511	rawsock_exit();
23b7869c LRV	512	err_rawsock:
c7fe3b52	513	nfc_genl_exit();
4d12b8b1 LRV	514	err_genl:
	515	class_unregister(&nfc_class);
	516	return rc;
3e256b8f LRV	517	}
	518
	519	static void __exit nfc_exit(void)
	520	{
c7fe3b52	521	af_nfc_exit();
23b7869c	522	rawsock_exit();
4d12b8b1	523	nfc_genl_exit();
3e256b8f LRV	524	class_unregister(&nfc_class);
	525	}
	526
	527	subsys_initcall(nfc_init);
	528	module_exit(nfc_exit);
	529
	530	MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>");
	531	MODULE_DESCRIPTION("NFC Core ver " VERSION);
	532	MODULE_VERSION(VERSION);
	533	MODULE_LICENSE("GPL");