[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 ": %s: " fmt, __func__

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/nfc.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;
}

int nfc_dep_link_up(struct nfc_dev *dev, int target_index,
					u8 comm_mode, u8 rf_mode)
{
	int rc = 0;

	pr_debug("dev_name=%s comm:%d rf:%d\n",
			dev_name(&dev->dev), comm_mode, rf_mode);

	if (!dev->ops->dep_link_up)
		return -EOPNOTSUPP;

	device_lock(&dev->dev);

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

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

	rc = dev->ops->dep_link_up(dev, target_index, comm_mode, rf_mode);

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

int nfc_dep_link_down(struct nfc_dev *dev)
{
	int rc = 0;

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

	if (!dev->ops->dep_link_down)
		return -EOPNOTSUPP;

	device_lock(&dev->dev);

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

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

	if (dev->dep_rf_mode == NFC_RF_TARGET) {
		rc = -EOPNOTSUPP;
		goto error;
	}

	rc = dev->ops->dep_link_down(dev);
	if (!rc) {
		dev->dep_link_up = false;
		nfc_genl_dep_link_down_event(dev);
	}

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

int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx,
					u8 comm_mode, u8 rf_mode)
{
	dev->dep_link_up = true;
	dev->dep_rf_mode = rf_mode;

	return nfc_genl_dep_link_up_event(dev, target_idx, comm_mode, rf_mode);
}
EXPORT_SYMBOL(nfc_dep_link_is_up);

/**
 * 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_send_skb - allocate a skb for data exchange responses
 *
 * @size: size to allocate
 * @gfp: gfp flags
 */
struct sk_buff *nfc_alloc_send_skb(struct nfc_dev *dev, struct sock *sk,
					unsigned int flags, unsigned int size,
					unsigned int *err)
{
	struct sk_buff *skb;
	unsigned int total_size;

	total_size = size +
		dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;

	skb = sock_alloc_send_skb(sk, total_size, flags & MSG_DONTWAIT, err);
	if (skb)
		skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);

	return skb;
}

/**
 * nfc_alloc_recv_skb - allocate a skb for data exchange responses
 *
 * @size: size to allocate
 * @gfp: gfp flags
 */
struct sk_buff *nfc_alloc_recv_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_recv_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
52858b51	24	#define pr_fmt(fmt) KBUILD_MODNAME ": %s: " fmt, __func__
ed1e0ad8	25
3e256b8f LRV	26	#include <linux/init.h>
	27	#include <linux/kernel.h>
	28	#include <linux/module.h>
	29	#include <linux/slab.h>
7c7cd3bf	30	#include <linux/nfc.h>
3e256b8f LRV	31
	32	#include "nfc.h"
	33
	34	#define VERSION "0.1"
	35
	36	int nfc_devlist_generation;
	37	DEFINE_MUTEX(nfc_devlist_mutex);
	38
8b3fe7b5 IE	39	/**
	40	* nfc_dev_up - turn on the NFC device
	41	*
	42	* @dev: The nfc device to be turned on
	43	*
	44	* The device remains up until the nfc_dev_down function is called.
	45	*/
	46	int nfc_dev_up(struct nfc_dev *dev)
	47	{
	48	int rc = 0;
	49
20c239c1	50	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
8b3fe7b5 IE	51
	52	device_lock(&dev->dev);
	53
	54	if (!device_is_registered(&dev->dev)) {
	55	rc = -ENODEV;
	56	goto error;
	57	}
	58
	59	if (dev->dev_up) {
	60	rc = -EALREADY;
	61	goto error;
	62	}
	63
	64	if (dev->ops->dev_up)
	65	rc = dev->ops->dev_up(dev);
	66
	67	if (!rc)
	68	dev->dev_up = true;
	69
	70	error:
	71	device_unlock(&dev->dev);
	72	return rc;
	73	}
	74
	75	/**
	76	* nfc_dev_down - turn off the NFC device
	77	*
	78	* @dev: The nfc device to be turned off
	79	*/
	80	int nfc_dev_down(struct nfc_dev *dev)
	81	{
	82	int rc = 0;
	83
20c239c1	84	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
8b3fe7b5 IE	85
	86	device_lock(&dev->dev);
	87
	88	if (!device_is_registered(&dev->dev)) {
	89	rc = -ENODEV;
	90	goto error;
	91	}
	92
	93	if (!dev->dev_up) {
	94	rc = -EALREADY;
	95	goto error;
	96	}
	97
	98	if (dev->polling \|\| dev->remote_activated) {
	99	rc = -EBUSY;
	100	goto error;
	101	}
	102
	103	if (dev->ops->dev_down)
	104	dev->ops->dev_down(dev);
	105
	106	dev->dev_up = false;
	107
	108	error:
	109	device_unlock(&dev->dev);
	110	return rc;
	111	}
	112
3e256b8f LRV	113	/**
	114	* nfc_start_poll - start polling for nfc targets
	115	*
	116	* @dev: The nfc device that must start polling
	117	* @protocols: bitset of nfc protocols that must be used for polling
	118	*
	119	* The device remains polling for targets until a target is found or
	120	* the nfc_stop_poll function is called.
	121	*/
	122	int nfc_start_poll(struct nfc_dev *dev, u32 protocols)
	123	{
	124	int rc;
	125
20c239c1 JP	126	pr_debug("dev_name=%s protocols=0x%x\n",
20c239c1 JP	127	dev_name(&dev->dev), protocols);
3e256b8f LRV	128
	129	if (!protocols)
	130	return -EINVAL;
	131
	132	device_lock(&dev->dev);
	133
	134	if (!device_is_registered(&dev->dev)) {
	135	rc = -ENODEV;
	136	goto error;
	137	}
	138
	139	if (dev->polling) {
	140	rc = -EBUSY;
	141	goto error;
	142	}
	143
	144	rc = dev->ops->start_poll(dev, protocols);
	145	if (!rc)
	146	dev->polling = true;
	147
	148	error:
	149	device_unlock(&dev->dev);
	150	return rc;
	151	}
	152
	153	/**
	154	* nfc_stop_poll - stop polling for nfc targets
	155	*
	156	* @dev: The nfc device that must stop polling
	157	*/
	158	int nfc_stop_poll(struct nfc_dev *dev)
	159	{
	160	int rc = 0;
	161
20c239c1	162	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
3e256b8f LRV	163
	164	device_lock(&dev->dev);
	165
	166	if (!device_is_registered(&dev->dev)) {
	167	rc = -ENODEV;
	168	goto error;
	169	}
	170
	171	if (!dev->polling) {
	172	rc = -EINVAL;
	173	goto error;
	174	}
	175
	176	dev->ops->stop_poll(dev);
	177	dev->polling = false;
	178
	179	error:
	180	device_unlock(&dev->dev);
	181	return rc;
	182	}
	183
1ed28f61 SO	184	int nfc_dep_link_up(struct nfc_dev *dev, int target_index,
	185	u8 comm_mode, u8 rf_mode)
	186	{
	187	int rc = 0;
	188
	189	pr_debug("dev_name=%s comm:%d rf:%d\n",
	190	dev_name(&dev->dev), comm_mode, rf_mode);
	191
	192	if (!dev->ops->dep_link_up)
	193	return -EOPNOTSUPP;
	194
	195	device_lock(&dev->dev);
	196
	197	if (!device_is_registered(&dev->dev)) {
	198	rc = -ENODEV;
	199	goto error;
	200	}
	201
	202	if (dev->dep_link_up == true) {
	203	rc = -EALREADY;
	204	goto error;
	205	}
	206
	207	rc = dev->ops->dep_link_up(dev, target_index, comm_mode, rf_mode);
	208
	209	error:
	210	device_unlock(&dev->dev);
	211	return rc;
	212	}
	213
	214	int nfc_dep_link_down(struct nfc_dev *dev)
	215	{
	216	int rc = 0;
	217
	218	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
	219
	220	if (!dev->ops->dep_link_down)
	221	return -EOPNOTSUPP;
	222
	223	device_lock(&dev->dev);
	224
	225	if (!device_is_registered(&dev->dev)) {
	226	rc = -ENODEV;
	227	goto error;
	228	}
	229
	230	if (dev->dep_link_up == false) {
	231	rc = -EALREADY;
	232	goto error;
	233	}
	234
	235	if (dev->dep_rf_mode == NFC_RF_TARGET) {
	236	rc = -EOPNOTSUPP;
	237	goto error;
	238	}
	239
	240	rc = dev->ops->dep_link_down(dev);
	241	if (!rc) {
	242	dev->dep_link_up = false;
	243	nfc_genl_dep_link_down_event(dev);
	244	}
	245
	246	error:
	247	device_unlock(&dev->dev);
248	return rc;
249	}
250
251	int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx,
252	u8 comm_mode, u8 rf_mode)
253	{
254	dev->dep_link_up = true;
255	dev->dep_rf_mode = rf_mode;
256
257	return nfc_genl_dep_link_up_event(dev, target_idx, comm_mode, rf_mode);
258	}
259	EXPORT_SYMBOL(nfc_dep_link_is_up);
260
3e256b8f LRV	261	/**
	262	* nfc_activate_target - prepare the target for data exchange
	263	*
	264	* @dev: The nfc device that found the target
	265	* @target_idx: index of the target that must be activated
	266	* @protocol: nfc protocol that will be used for data exchange
	267	*/
	268	int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol)
	269	{
	270	int rc;
	271
20c239c1 JP	272	pr_debug("dev_name=%s target_idx=%u protocol=%u\n",
20c239c1 JP	273	dev_name(&dev->dev), target_idx, protocol);
3e256b8f LRV	274
	275	device_lock(&dev->dev);
	276
	277	if (!device_is_registered(&dev->dev)) {
	278	rc = -ENODEV;
	279	goto error;
	280	}
	281
	282	rc = dev->ops->activate_target(dev, target_idx, protocol);
8b3fe7b5 IE	283	if (!rc)
8b3fe7b5 IE	284	dev->remote_activated = true;
3e256b8f LRV	285
	286	error:
	287	device_unlock(&dev->dev);
	288	return rc;
	289	}
	290
	291	/**
	292	* nfc_deactivate_target - deactivate a nfc target
	293	*
	294	* @dev: The nfc device that found the target
	295	* @target_idx: index of the target that must be deactivated
	296	*/
	297	int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx)
	298	{
	299	int rc = 0;
	300
20c239c1 JP	301	pr_debug("dev_name=%s target_idx=%u\n",
20c239c1 JP	302	dev_name(&dev->dev), target_idx);
3e256b8f LRV	303
	304	device_lock(&dev->dev);
	305
	306	if (!device_is_registered(&dev->dev)) {
	307	rc = -ENODEV;
	308	goto error;
	309	}
	310
	311	dev->ops->deactivate_target(dev, target_idx);
8b3fe7b5	312	dev->remote_activated = false;
3e256b8f LRV	313
	314	error:
	315	device_unlock(&dev->dev);
	316	return rc;
	317	}
	318
	319	/**
	320	* nfc_data_exchange - transceive data
	321	*
	322	* @dev: The nfc device that found the target
	323	* @target_idx: index of the target
	324	* @skb: data to be sent
	325	* @cb: callback called when the response is received
	326	* @cb_context: parameter for the callback function
	327	*
	328	* The user must wait for the callback before calling this function again.
	329	*/
	330	int nfc_data_exchange(struct nfc_dev *dev, u32 target_idx,
	331	struct sk_buff *skb,
	332	data_exchange_cb_t cb,
	333	void *cb_context)
	334	{
	335	int rc;
	336
20c239c1 JP	337	pr_debug("dev_name=%s target_idx=%u skb->len=%u\n",
20c239c1 JP	338	dev_name(&dev->dev), target_idx, skb->len);
3e256b8f LRV	339
	340	device_lock(&dev->dev);
	341
	342	if (!device_is_registered(&dev->dev)) {
	343	rc = -ENODEV;
	344	kfree_skb(skb);
	345	goto error;
	346	}
	347
	348	rc = dev->ops->data_exchange(dev, target_idx, skb, cb, cb_context);
	349
	350	error:
	351	device_unlock(&dev->dev);
	352	return rc;
	353	}
	354
	355	/**
7c7cd3bf	356	* nfc_alloc_send_skb - allocate a skb for data exchange responses
3e256b8f LRV	357	*
	358	* @size: size to allocate
	359	* @gfp: gfp flags
	360	*/
7c7cd3bf SO	361	struct sk_buff nfc_alloc_send_skb(struct nfc_dev dev, struct sock *sk,
	362	unsigned int flags, unsigned int size,
	363	unsigned int *err)
	364	{
	365	struct sk_buff *skb;
	366	unsigned int total_size;
	367
	368	total_size = size +
	369	dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
	370
	371	skb = sock_alloc_send_skb(sk, total_size, flags & MSG_DONTWAIT, err);
	372	if (skb)
	373	skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
	374
	375	return skb;
	376	}
	377
	378	/**
	379	* nfc_alloc_recv_skb - allocate a skb for data exchange responses
	380	*
	381	* @size: size to allocate
	382	* @gfp: gfp flags
	383	*/
	384	struct sk_buff *nfc_alloc_recv_skb(unsigned int size, gfp_t gfp)
3e256b8f LRV	385	{
	386	struct sk_buff *skb;
	387	unsigned int total_size;
	388
	389	total_size = size + 1;
	390	skb = alloc_skb(total_size, gfp);
	391
	392	if (skb)
	393	skb_reserve(skb, 1);
	394
	395	return skb;
	396	}
7c7cd3bf	397	EXPORT_SYMBOL(nfc_alloc_recv_skb);
3e256b8f	398
4d12b8b1 LRV	399	/**
	400	* nfc_targets_found - inform that targets were found
	401	*
	402	* @dev: The nfc device that found the targets
	403	* @targets: array of nfc targets found
	404	* @ntargets: targets array size
	405	*
	406	* The device driver must call this function when one or many nfc targets
	407	* are found. After calling this function, the device driver must stop
	408	* polling for targets.
	409	*/
	410	int nfc_targets_found(struct nfc_dev dev, struct nfc_target targets,
	411	int n_targets)
	412	{
	413	int i;
	414
20c239c1	415	pr_debug("dev_name=%s n_targets=%d\n", dev_name(&dev->dev), n_targets);
4d12b8b1 LRV	416
	417	dev->polling = false;
	418
	419	for (i = 0; i < n_targets; i++)
	420	targets[i].idx = dev->target_idx++;
	421
	422	spin_lock_bh(&dev->targets_lock);
	423
	424	dev->targets_generation++;
	425
	426	kfree(dev->targets);
	427	dev->targets = kmemdup(targets, n_targets * sizeof(struct nfc_target),
	428	GFP_ATOMIC);
	429
	430	if (!dev->targets) {
	431	dev->n_targets = 0;
	432	spin_unlock_bh(&dev->targets_lock);
	433	return -ENOMEM;
	434	}
	435
	436	dev->n_targets = n_targets;
	437	spin_unlock_bh(&dev->targets_lock);
	438
	439	nfc_genl_targets_found(dev);
	440
	441	return 0;
	442	}
	443	EXPORT_SYMBOL(nfc_targets_found);
	444
3e256b8f LRV	445	static void nfc_release(struct device *d)
	446	{
	447	struct nfc_dev *dev = to_nfc_dev(d);
	448
20c239c1	449	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
3e256b8f	450
4d12b8b1 LRV	451	nfc_genl_data_exit(&dev->genl_data);
4d12b8b1 LRV	452	kfree(dev->targets);
3e256b8f LRV	453	kfree(dev);
	454	}
	455
	456	struct class nfc_class = {
	457	.name = "nfc",
	458	.dev_release = nfc_release,
	459	};
	460	EXPORT_SYMBOL(nfc_class);
	461
	462	static int match_idx(struct device d, void data)
	463	{
	464	struct nfc_dev *dev = to_nfc_dev(d);
	465	unsigned *idx = data;
	466
	467	return dev->idx == *idx;
	468	}
	469
	470	struct nfc_dev *nfc_get_device(unsigned idx)
	471	{
	472	struct device *d;
	473
	474	d = class_find_device(&nfc_class, NULL, &idx, match_idx);
	475	if (!d)
	476	return NULL;
	477
	478	return to_nfc_dev(d);
	479	}
	480
	481	/**
	482	* nfc_allocate_device - allocate a new nfc device
	483	*
	484	* @ops: device operations
	485	* @supported_protocols: NFC protocols supported by the device
	486	*/
	487	struct nfc_dev nfc_allocate_device(struct nfc_ops ops,
e8753043 SO	488	u32 supported_protocols,
	489	int tx_headroom,
	490	int tx_tailroom)
3e256b8f LRV	491	{
	492	static atomic_t dev_no = ATOMIC_INIT(0);
	493	struct nfc_dev *dev;
	494
	495	if (!ops->start_poll \|\| !ops->stop_poll \|\| !ops->activate_target \|\|
	496	!ops->deactivate_target \|\| !ops->data_exchange)
	497	return NULL;
	498
	499	if (!supported_protocols)
	500	return NULL;
	501
	502	dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL);
	503	if (!dev)
	504	return NULL;
	505
	506	dev->dev.class = &nfc_class;
	507	dev->idx = atomic_inc_return(&dev_no) - 1;
	508	dev_set_name(&dev->dev, "nfc%d", dev->idx);
	509	device_initialize(&dev->dev);
	510
	511	dev->ops = ops;
	512	dev->supported_protocols = supported_protocols;
e8753043 SO	513	dev->tx_headroom = tx_headroom;
e8753043 SO	514	dev->tx_tailroom = tx_tailroom;
3e256b8f	515
4d12b8b1 LRV	516	spin_lock_init(&dev->targets_lock);
	517	nfc_genl_data_init(&dev->genl_data);
	518
	519	/* first generation must not be 0 */
	520	dev->targets_generation = 1;
	521
3e256b8f LRV	522	return dev;
	523	}
	524	EXPORT_SYMBOL(nfc_allocate_device);
	525
	526	/**
	527	* nfc_register_device - register a nfc device in the nfc subsystem
	528	*
	529	* @dev: The nfc device to register
	530	*/
	531	int nfc_register_device(struct nfc_dev *dev)
	532	{
	533	int rc;
	534
20c239c1	535	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
3e256b8f LRV	536
	537	mutex_lock(&nfc_devlist_mutex);
	538	nfc_devlist_generation++;
	539	rc = device_add(&dev->dev);
	540	mutex_unlock(&nfc_devlist_mutex);
	541
4d12b8b1 LRV	542	if (rc < 0)
	543	return rc;
	544
	545	rc = nfc_genl_device_added(dev);
	546	if (rc)
20c239c1 JP	547	pr_debug("The userspace won't be notified that the device %s was added\n",
20c239c1 JP	548	dev_name(&dev->dev));
4d12b8b1 LRV	549
4d12b8b1 LRV	550	return 0;
3e256b8f LRV	551	}
	552	EXPORT_SYMBOL(nfc_register_device);
	553
	554	/**
	555	* nfc_unregister_device - unregister a nfc device in the nfc subsystem
	556	*
	557	* @dev: The nfc device to unregister
	558	*/
	559	void nfc_unregister_device(struct nfc_dev *dev)
	560	{
4d12b8b1 LRV	561	int rc;
4d12b8b1 LRV	562
20c239c1	563	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
3e256b8f LRV	564
	565	mutex_lock(&nfc_devlist_mutex);
	566	nfc_devlist_generation++;
	567
	568	/* lock to avoid unregistering a device while an operation
	569	is in progress */
	570	device_lock(&dev->dev);
	571	device_del(&dev->dev);
	572	device_unlock(&dev->dev);
	573
	574	mutex_unlock(&nfc_devlist_mutex);
4d12b8b1 LRV	575
	576	rc = nfc_genl_device_removed(dev);
	577	if (rc)
20c239c1 JP	578	pr_debug("The userspace won't be notified that the device %s was removed\n",
20c239c1 JP	579	dev_name(&dev->dev));
4d12b8b1	580
3e256b8f LRV	581	}
	582	EXPORT_SYMBOL(nfc_unregister_device);
	583
	584	static int __init nfc_init(void)
	585	{
4d12b8b1 LRV	586	int rc;
4d12b8b1 LRV	587
ed1e0ad8	588	pr_info("NFC Core ver %s\n", VERSION);
3e256b8f	589
4d12b8b1 LRV	590	rc = class_register(&nfc_class);
	591	if (rc)
	592	return rc;
	593
	594	rc = nfc_genl_init();
	595	if (rc)
	596	goto err_genl;
	597
	598	/* the first generation must not be 0 */
	599	nfc_devlist_generation = 1;
	600
23b7869c LRV	601	rc = rawsock_init();
	602	if (rc)
	603	goto err_rawsock;
	604
c7fe3b52 AAJ	605	rc = af_nfc_init();
	606	if (rc)
	607	goto err_af_nfc;
	608
4d12b8b1 LRV	609	return 0;
4d12b8b1 LRV	610
c7fe3b52	611	err_af_nfc:
23b7869c LRV	612	rawsock_exit();
23b7869c LRV	613	err_rawsock:
c7fe3b52	614	nfc_genl_exit();
4d12b8b1 LRV	615	err_genl:
	616	class_unregister(&nfc_class);
	617	return rc;
3e256b8f LRV	618	}
	619
	620	static void __exit nfc_exit(void)
	621	{
c7fe3b52	622	af_nfc_exit();
23b7869c	623	rawsock_exit();
4d12b8b1	624	nfc_genl_exit();
3e256b8f LRV	625	class_unregister(&nfc_class);
	626	}
	627
	628	subsys_initcall(nfc_init);
	629	module_exit(nfc_exit);
	630
	631	MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>");
	632	MODULE_DESCRIPTION("NFC Core ver " VERSION);
	633	MODULE_VERSION(VERSION);
	634	MODULE_LICENSE("GPL");