[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)
{
	int rc = 0;
	u8 *gb;
	size_t gb_len;

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

	gb = nfc_llcp_general_bytes(dev, &gb_len);
	if (gb_len > NFC_MAX_GT_LEN) {
		rc = -EINVAL;
		goto error;
	}

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

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_llcp_mac_is_down(dev);
		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;

	nfc_llcp_mac_is_up(dev, target_idx, comm_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;
}

int nfc_set_remote_general_bytes(struct nfc_dev *dev, u8 *gb, u8 gb_len)
{
	pr_debug("dev_name=%s gb_len=%d\n", dev_name(&dev->dev), gb_len);

	if (gb_len > NFC_MAX_GT_LEN)
		return -EINVAL;

	return nfc_llcp_set_remote_gb(dev, gb, gb_len);
}
EXPORT_SYMBOL(nfc_set_remote_general_bytes);

/**
 * 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);

int nfc_target_lost(struct nfc_dev *dev, u32 target_idx)
{
	struct nfc_target *tg;
	int i;

	pr_debug("dev_name %s n_target %d\n", dev_name(&dev->dev), target_idx);

	spin_lock_bh(&dev->targets_lock);

	for (i = 0; i < dev->n_targets; i++) {
		tg = &dev->targets[i];
		if (tg->idx == target_idx)
			break;
	}

	if (i == dev->n_targets) {
		spin_unlock_bh(&dev->targets_lock);
		return -EINVAL;
	}

	dev->targets_generation++;
	dev->n_targets--;

	if (dev->n_targets) {
		memcpy(&dev->targets[i], &dev->targets[i + 1],
		       (dev->n_targets - i) * sizeof(struct nfc_target));
	} else {
		kfree(dev->targets);
		dev->targets = NULL;
	}

	spin_unlock_bh(&dev->targets_lock);

	nfc_genl_target_lost(dev, target_idx);

	return 0;
}
EXPORT_SYMBOL(nfc_target_lost);

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_llcp_register_device(dev);
	if (rc)
		pr_err("Could not register llcp device\n");

	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);

	nfc_llcp_unregister_device(dev);

	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 = nfc_llcp_init();
	if (rc)
		goto err_llcp_sock;

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

	return 0;

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

static void __exit nfc_exit(void)
{
	af_nfc_exit();
	nfc_llcp_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
47807d3d	184	int nfc_dep_link_up(struct nfc_dev *dev, int target_index, u8 comm_mode)
1ed28f61 SO	185	{
1ed28f61 SO	186	int rc = 0;
47807d3d SO	187	u8 *gb;
47807d3d SO	188	size_t gb_len;
1ed28f61	189
47807d3d	190	pr_debug("dev_name=%s comm %d\n", dev_name(&dev->dev), comm_mode);
1ed28f61 SO	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
47807d3d SO	207	gb = nfc_llcp_general_bytes(dev, &gb_len);
	208	if (gb_len > NFC_MAX_GT_LEN) {
	209	rc = -EINVAL;
	210	goto error;
	211	}
	212
	213	rc = dev->ops->dep_link_up(dev, target_index, comm_mode, gb, gb_len);
1ed28f61 SO	214
	215	error:
	216	device_unlock(&dev->dev);
	217	return rc;
	218	}
	219
	220	int nfc_dep_link_down(struct nfc_dev *dev)
	221	{
	222	int rc = 0;
	223
	224	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
	225
	226	if (!dev->ops->dep_link_down)
	227	return -EOPNOTSUPP;
	228
	229	device_lock(&dev->dev);
	230
	231	if (!device_is_registered(&dev->dev)) {
	232	rc = -ENODEV;
	233	goto error;
	234	}
	235
	236	if (dev->dep_link_up == false) {
	237	rc = -EALREADY;
	238	goto error;
	239	}
	240
	241	if (dev->dep_rf_mode == NFC_RF_TARGET) {
	242	rc = -EOPNOTSUPP;
	243	goto error;
	244	}
	245
	246	rc = dev->ops->dep_link_down(dev);
	247	if (!rc) {
	248	dev->dep_link_up = false;
d646960f	249	nfc_llcp_mac_is_down(dev);
1ed28f61 SO	250	nfc_genl_dep_link_down_event(dev);
	251	}
	252
	253	error:
	254	device_unlock(&dev->dev);
	255	return rc;
	256	}
	257
	258	int nfc_dep_link_is_up(struct nfc_dev *dev, u32 target_idx,
0a40acb2	259	u8 comm_mode, u8 rf_mode)
1ed28f61 SO	260	{
	261	dev->dep_link_up = true;
	262	dev->dep_rf_mode = rf_mode;
	263
d646960f SO	264	nfc_llcp_mac_is_up(dev, target_idx, comm_mode, rf_mode);
d646960f SO	265
1ed28f61 SO	266	return nfc_genl_dep_link_up_event(dev, target_idx, comm_mode, rf_mode);
	267	}
	268	EXPORT_SYMBOL(nfc_dep_link_is_up);
	269
3e256b8f LRV	270	/**
	271	* nfc_activate_target - prepare the target for data exchange
	272	*
	273	* @dev: The nfc device that found the target
	274	* @target_idx: index of the target that must be activated
	275	* @protocol: nfc protocol that will be used for data exchange
	276	*/
	277	int nfc_activate_target(struct nfc_dev *dev, u32 target_idx, u32 protocol)
	278	{
	279	int rc;
	280
20c239c1 JP	281	pr_debug("dev_name=%s target_idx=%u protocol=%u\n",
20c239c1 JP	282	dev_name(&dev->dev), target_idx, protocol);
3e256b8f LRV	283
	284	device_lock(&dev->dev);
	285
	286	if (!device_is_registered(&dev->dev)) {
	287	rc = -ENODEV;
	288	goto error;
	289	}
	290
	291	rc = dev->ops->activate_target(dev, target_idx, protocol);
8b3fe7b5 IE	292	if (!rc)
8b3fe7b5 IE	293	dev->remote_activated = true;
3e256b8f LRV	294
	295	error:
	296	device_unlock(&dev->dev);
	297	return rc;
	298	}
	299
	300	/**
	301	* nfc_deactivate_target - deactivate a nfc target
	302	*
	303	* @dev: The nfc device that found the target
	304	* @target_idx: index of the target that must be deactivated
	305	*/
	306	int nfc_deactivate_target(struct nfc_dev *dev, u32 target_idx)
	307	{
	308	int rc = 0;
	309
20c239c1 JP	310	pr_debug("dev_name=%s target_idx=%u\n",
20c239c1 JP	311	dev_name(&dev->dev), target_idx);
3e256b8f LRV	312
	313	device_lock(&dev->dev);
	314
	315	if (!device_is_registered(&dev->dev)) {
	316	rc = -ENODEV;
	317	goto error;
	318	}
	319
	320	dev->ops->deactivate_target(dev, target_idx);
8b3fe7b5	321	dev->remote_activated = false;
3e256b8f LRV	322
	323	error:
	324	device_unlock(&dev->dev);
	325	return rc;
	326	}
	327
	328	/**
	329	* nfc_data_exchange - transceive data
	330	*
	331	* @dev: The nfc device that found the target
	332	* @target_idx: index of the target
	333	* @skb: data to be sent
	334	* @cb: callback called when the response is received
	335	* @cb_context: parameter for the callback function
	336	*
	337	* The user must wait for the callback before calling this function again.
	338	*/
0a40acb2 SO	339	int nfc_data_exchange(struct nfc_dev dev, u32 target_idx, struct sk_buff skb,
0a40acb2 SO	340	data_exchange_cb_t cb, void *cb_context)
3e256b8f LRV	341	{
	342	int rc;
	343
20c239c1 JP	344	pr_debug("dev_name=%s target_idx=%u skb->len=%u\n",
20c239c1 JP	345	dev_name(&dev->dev), target_idx, skb->len);
3e256b8f LRV	346
	347	device_lock(&dev->dev);
	348
	349	if (!device_is_registered(&dev->dev)) {
	350	rc = -ENODEV;
	351	kfree_skb(skb);
	352	goto error;
	353	}
	354
	355	rc = dev->ops->data_exchange(dev, target_idx, skb, cb, cb_context);
	356
	357	error:
	358	device_unlock(&dev->dev);
	359	return rc;
	360	}
	361
541d920b SO	362	int nfc_set_remote_general_bytes(struct nfc_dev dev, u8 gb, u8 gb_len)
541d920b SO	363	{
0a40acb2	364	pr_debug("dev_name=%s gb_len=%d\n", dev_name(&dev->dev), gb_len);
541d920b SO	365
	366	if (gb_len > NFC_MAX_GT_LEN)
	367	return -EINVAL;
	368
d646960f	369	return nfc_llcp_set_remote_gb(dev, gb, gb_len);
541d920b SO	370	}
	371	EXPORT_SYMBOL(nfc_set_remote_general_bytes);
	372
3e256b8f	373	/**
7c7cd3bf	374	* nfc_alloc_send_skb - allocate a skb for data exchange responses
3e256b8f LRV	375	*
	376	* @size: size to allocate
	377	* @gfp: gfp flags
	378	*/
7c7cd3bf	379	struct sk_buff nfc_alloc_send_skb(struct nfc_dev dev, struct sock *sk,
0a40acb2 SO	380	unsigned int flags, unsigned int size,
0a40acb2 SO	381	unsigned int *err)
7c7cd3bf SO	382	{
	383	struct sk_buff *skb;
	384	unsigned int total_size;
	385
	386	total_size = size +
	387	dev->tx_headroom + dev->tx_tailroom + NFC_HEADER_SIZE;
	388
	389	skb = sock_alloc_send_skb(sk, total_size, flags & MSG_DONTWAIT, err);
	390	if (skb)
	391	skb_reserve(skb, dev->tx_headroom + NFC_HEADER_SIZE);
	392
	393	return skb;
	394	}
	395
	396	/**
	397	* nfc_alloc_recv_skb - allocate a skb for data exchange responses
	398	*
	399	* @size: size to allocate
	400	* @gfp: gfp flags
	401	*/
	402	struct sk_buff *nfc_alloc_recv_skb(unsigned int size, gfp_t gfp)
3e256b8f LRV	403	{
	404	struct sk_buff *skb;
	405	unsigned int total_size;
	406
	407	total_size = size + 1;
	408	skb = alloc_skb(total_size, gfp);
	409
	410	if (skb)
	411	skb_reserve(skb, 1);
	412
	413	return skb;
	414	}
7c7cd3bf	415	EXPORT_SYMBOL(nfc_alloc_recv_skb);
3e256b8f	416
4d12b8b1 LRV	417	/**
	418	* nfc_targets_found - inform that targets were found
	419	*
	420	* @dev: The nfc device that found the targets
	421	* @targets: array of nfc targets found
	422	* @ntargets: targets array size
	423	*
	424	* The device driver must call this function when one or many nfc targets
	425	* are found. After calling this function, the device driver must stop
	426	* polling for targets.
	427	*/
0a40acb2 SO	428	int nfc_targets_found(struct nfc_dev *dev,
0a40acb2 SO	429	struct nfc_target *targets, int n_targets)
4d12b8b1	430	{
c4fbb651 SO	431	int i;
c4fbb651 SO	432
20c239c1	433	pr_debug("dev_name=%s n_targets=%d\n", dev_name(&dev->dev), n_targets);
4d12b8b1 LRV	434
	435	dev->polling = false;
	436
c4fbb651 SO	437	for (i = 0; i < n_targets; i++)
	438	targets[i].idx = dev->target_idx++;
	439
4d12b8b1 LRV	440	spin_lock_bh(&dev->targets_lock);
	441
	442	dev->targets_generation++;
	443
	444	kfree(dev->targets);
	445	dev->targets = kmemdup(targets, n_targets * sizeof(struct nfc_target),
0a40acb2	446	GFP_ATOMIC);
4d12b8b1 LRV	447
	448	if (!dev->targets) {
	449	dev->n_targets = 0;
	450	spin_unlock_bh(&dev->targets_lock);
	451	return -ENOMEM;
	452	}
	453
	454	dev->n_targets = n_targets;
	455	spin_unlock_bh(&dev->targets_lock);
	456
	457	nfc_genl_targets_found(dev);
	458
	459	return 0;
	460	}
	461	EXPORT_SYMBOL(nfc_targets_found);
	462
e1da0efa EL	463	int nfc_target_lost(struct nfc_dev *dev, u32 target_idx)
	464	{
	465	struct nfc_target *tg;
	466	int i;
	467
	468	pr_debug("dev_name %s n_target %d\n", dev_name(&dev->dev), target_idx);
	469
	470	spin_lock_bh(&dev->targets_lock);
	471
	472	for (i = 0; i < dev->n_targets; i++) {
	473	tg = &dev->targets[i];
	474	if (tg->idx == target_idx)
	475	break;
	476	}
	477
	478	if (i == dev->n_targets) {
	479	spin_unlock_bh(&dev->targets_lock);
	480	return -EINVAL;
	481	}
	482
	483	dev->targets_generation++;
	484	dev->n_targets--;
	485
	486	if (dev->n_targets) {
	487	memcpy(&dev->targets[i], &dev->targets[i + 1],
	488	(dev->n_targets - i) * sizeof(struct nfc_target));
	489	} else {
	490	kfree(dev->targets);
	491	dev->targets = NULL;
	492	}
	493
	494	spin_unlock_bh(&dev->targets_lock);
	495
	496	nfc_genl_target_lost(dev, target_idx);
	497
	498	return 0;
	499	}
	500	EXPORT_SYMBOL(nfc_target_lost);
	501
3e256b8f LRV	502	static void nfc_release(struct device *d)
	503	{
	504	struct nfc_dev *dev = to_nfc_dev(d);
	505
20c239c1	506	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
3e256b8f	507
4d12b8b1 LRV	508	nfc_genl_data_exit(&dev->genl_data);
4d12b8b1 LRV	509	kfree(dev->targets);
3e256b8f LRV	510	kfree(dev);
	511	}
	512
	513	struct class nfc_class = {
	514	.name = "nfc",
	515	.dev_release = nfc_release,
	516	};
	517	EXPORT_SYMBOL(nfc_class);
	518
	519	static int match_idx(struct device d, void data)
	520	{
	521	struct nfc_dev *dev = to_nfc_dev(d);
	522	unsigned *idx = data;
	523
	524	return dev->idx == *idx;
	525	}
	526
	527	struct nfc_dev *nfc_get_device(unsigned idx)
	528	{
	529	struct device *d;
	530
	531	d = class_find_device(&nfc_class, NULL, &idx, match_idx);
	532	if (!d)
	533	return NULL;
	534
	535	return to_nfc_dev(d);
	536	}
	537
	538	/**
	539	* nfc_allocate_device - allocate a new nfc device
	540	*
	541	* @ops: device operations
	542	* @supported_protocols: NFC protocols supported by the device
	543	*/
	544	struct nfc_dev nfc_allocate_device(struct nfc_ops ops,
0a40acb2 SO	545	u32 supported_protocols,
0a40acb2 SO	546	int tx_headroom, int tx_tailroom)
3e256b8f LRV	547	{
	548	static atomic_t dev_no = ATOMIC_INIT(0);
	549	struct nfc_dev *dev;
	550
	551	if (!ops->start_poll \|\| !ops->stop_poll \|\| !ops->activate_target \|\|
0a40acb2	552	!ops->deactivate_target \|\| !ops->data_exchange)
3e256b8f LRV	553	return NULL;
	554
	555	if (!supported_protocols)
	556	return NULL;
	557
	558	dev = kzalloc(sizeof(struct nfc_dev), GFP_KERNEL);
	559	if (!dev)
	560	return NULL;
	561
	562	dev->dev.class = &nfc_class;
	563	dev->idx = atomic_inc_return(&dev_no) - 1;
	564	dev_set_name(&dev->dev, "nfc%d", dev->idx);
	565	device_initialize(&dev->dev);
	566
	567	dev->ops = ops;
	568	dev->supported_protocols = supported_protocols;
e8753043 SO	569	dev->tx_headroom = tx_headroom;
e8753043 SO	570	dev->tx_tailroom = tx_tailroom;
3e256b8f	571
4d12b8b1 LRV	572	spin_lock_init(&dev->targets_lock);
	573	nfc_genl_data_init(&dev->genl_data);
	574
	575	/* first generation must not be 0 */
	576	dev->targets_generation = 1;
	577
3e256b8f LRV	578	return dev;
	579	}
	580	EXPORT_SYMBOL(nfc_allocate_device);
	581
	582	/**
	583	* nfc_register_device - register a nfc device in the nfc subsystem
	584	*
	585	* @dev: The nfc device to register
	586	*/
	587	int nfc_register_device(struct nfc_dev *dev)
	588	{
	589	int rc;
	590
20c239c1	591	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
3e256b8f LRV	592
	593	mutex_lock(&nfc_devlist_mutex);
	594	nfc_devlist_generation++;
	595	rc = device_add(&dev->dev);
	596	mutex_unlock(&nfc_devlist_mutex);
	597
4d12b8b1 LRV	598	if (rc < 0)
	599	return rc;
	600
d646960f SO	601	rc = nfc_llcp_register_device(dev);
	602	if (rc)
	603	pr_err("Could not register llcp device\n");
	604
4d12b8b1 LRV	605	rc = nfc_genl_device_added(dev);
4d12b8b1 LRV	606	if (rc)
20c239c1 JP	607	pr_debug("The userspace won't be notified that the device %s was added\n",
20c239c1 JP	608	dev_name(&dev->dev));
4d12b8b1 LRV	609
4d12b8b1 LRV	610	return 0;
3e256b8f LRV	611	}
	612	EXPORT_SYMBOL(nfc_register_device);
	613
	614	/**
	615	* nfc_unregister_device - unregister a nfc device in the nfc subsystem
	616	*
	617	* @dev: The nfc device to unregister
	618	*/
	619	void nfc_unregister_device(struct nfc_dev *dev)
	620	{
4d12b8b1 LRV	621	int rc;
4d12b8b1 LRV	622
20c239c1	623	pr_debug("dev_name=%s\n", dev_name(&dev->dev));
3e256b8f LRV	624
	625	mutex_lock(&nfc_devlist_mutex);
	626	nfc_devlist_generation++;
	627
	628	/* lock to avoid unregistering a device while an operation
	629	is in progress */
	630	device_lock(&dev->dev);
	631	device_del(&dev->dev);
	632	device_unlock(&dev->dev);
	633
	634	mutex_unlock(&nfc_devlist_mutex);
4d12b8b1	635
d646960f SO	636	nfc_llcp_unregister_device(dev);
d646960f SO	637
4d12b8b1 LRV	638	rc = nfc_genl_device_removed(dev);
4d12b8b1 LRV	639	if (rc)
20c239c1 JP	640	pr_debug("The userspace won't be notified that the device %s was removed\n",
20c239c1 JP	641	dev_name(&dev->dev));
4d12b8b1	642
3e256b8f LRV	643	}
	644	EXPORT_SYMBOL(nfc_unregister_device);
	645
	646	static int __init nfc_init(void)
	647	{
4d12b8b1 LRV	648	int rc;
4d12b8b1 LRV	649
ed1e0ad8	650	pr_info("NFC Core ver %s\n", VERSION);
3e256b8f	651
4d12b8b1 LRV	652	rc = class_register(&nfc_class);
	653	if (rc)
	654	return rc;
	655
	656	rc = nfc_genl_init();
	657	if (rc)
	658	goto err_genl;
	659
	660	/* the first generation must not be 0 */
	661	nfc_devlist_generation = 1;
	662
23b7869c LRV	663	rc = rawsock_init();
	664	if (rc)
	665	goto err_rawsock;
	666
d646960f SO	667	rc = nfc_llcp_init();
	668	if (rc)
	669	goto err_llcp_sock;
	670
c7fe3b52 AAJ	671	rc = af_nfc_init();
	672	if (rc)
	673	goto err_af_nfc;
	674
4d12b8b1 LRV	675	return 0;
4d12b8b1 LRV	676
c7fe3b52	677	err_af_nfc:
d646960f SO	678	nfc_llcp_exit();
d646960f SO	679	err_llcp_sock:
23b7869c LRV	680	rawsock_exit();
23b7869c LRV	681	err_rawsock:
c7fe3b52	682	nfc_genl_exit();
4d12b8b1 LRV	683	err_genl:
	684	class_unregister(&nfc_class);
	685	return rc;
3e256b8f LRV	686	}
	687
	688	static void __exit nfc_exit(void)
	689	{
c7fe3b52	690	af_nfc_exit();
d646960f	691	nfc_llcp_exit();
23b7869c	692	rawsock_exit();
4d12b8b1	693	nfc_genl_exit();
3e256b8f LRV	694	class_unregister(&nfc_class);
	695	}
	696
	697	subsys_initcall(nfc_init);
	698	module_exit(nfc_exit);
	699
	700	MODULE_AUTHOR("Lauro Ramos Venancio <lauro.venancio@openbossa.org>");
	701	MODULE_DESCRIPTION("NFC Core ver " VERSION);
	702	MODULE_VERSION(VERSION);
	703	MODULE_LICENSE("GPL");