/*
   * Copyright (C) 2011 Instituto Nokia de Tecnologia
   *
   * Authors:
   *    Aloisio Almeida Jr <aloisio.almeida@openbossa.org>
   *    Lauro Ramos Venancio <lauro.venancio@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, see <http://www.gnu.org/licenses/>.

   */
  
  #include <linux/nfc.h>

  #include <linux/module.h>

  
  #include "nfc.h"
  
  static DEFINE_RWLOCK(proto_tab_lock);
  static const struct nfc_protocol *proto_tab[NFC_SOCKPROTO_MAX];
  
  static int nfc_sock_create(struct net *net, struct socket *sock, int proto,

  			   int kern)

  {
  	int rc = -EPROTONOSUPPORT;
  
  	if (net != &init_net)
  		return -EAFNOSUPPORT;
  
  	if (proto < 0 || proto >= NFC_SOCKPROTO_MAX)
  		return -EINVAL;
  
  	read_lock(&proto_tab_lock);
  	if (proto_tab[proto] &&	try_module_get(proto_tab[proto]->owner)) {

  		rc = proto_tab[proto]->create(net, sock, proto_tab[proto], kern);

  		module_put(proto_tab[proto]->owner);
  	}
  	read_unlock(&proto_tab_lock);
  
  	return rc;
  }

  static const struct net_proto_family nfc_sock_family_ops = {

  	.owner  = THIS_MODULE,
  	.family = PF_NFC,
  	.create = nfc_sock_create,
  };
  
  int nfc_proto_register(const struct nfc_protocol *nfc_proto)
  {
  	int rc;
  
  	if (nfc_proto->id < 0 || nfc_proto->id >= NFC_SOCKPROTO_MAX)
  		return -EINVAL;
  
  	rc = proto_register(nfc_proto->proto, 0);
  	if (rc)
  		return rc;
  
  	write_lock(&proto_tab_lock);
  	if (proto_tab[nfc_proto->id])
  		rc = -EBUSY;
  	else
  		proto_tab[nfc_proto->id] = nfc_proto;
  	write_unlock(&proto_tab_lock);
  
  	return rc;
  }
  EXPORT_SYMBOL(nfc_proto_register);
  
  void nfc_proto_unregister(const struct nfc_protocol *nfc_proto)
  {
  	write_lock(&proto_tab_lock);
  	proto_tab[nfc_proto->id] = NULL;
  	write_unlock(&proto_tab_lock);
  
  	proto_unregister(nfc_proto->proto);
  }
  EXPORT_SYMBOL(nfc_proto_unregister);
  
  int __init af_nfc_init(void)
  {
  	return sock_register(&nfc_sock_family_ops);
  }
  
  void af_nfc_exit(void)
  {
  	sock_unregister(PF_NFC);
  }