text: /*
   * Copyright (C) 2007-2012 Siemens AG
   *
   * Written by:
   * Alexander Smirnov <alex.bluesman.smirnov@gmail.com>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2
   * as published by the Free Software Foundation.
   *
   * 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.
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/netdevice.h>
  
  #include <net/netlink.h>
  #include <net/nl802154.h>
  #include <net/mac802154.h>
  #include <net/ieee802154_netdev.h>
  #include <net/route.h>
  #include <net/cfg802154.h>
  
  #include "ieee802154_i.h"
  #include "cfg.h"
  
  static void ieee802154_tasklet_handler(unsigned long data)
  {
  	struct ieee802154_local *local = (struct ieee802154_local *)data;
  	struct sk_buff *skb;
  
  	while ((skb = skb_dequeue(&local->skb_queue))) {
  		switch (skb->pkt_type) {
  		case IEEE802154_RX_MSG:
  			/* Clear skb->pkt_type in order to not confuse kernel
  			 * netstack.
  			 */
  			skb->pkt_type = 0;
  			ieee802154_rx(&local->hw, skb);
  			break;
  		default:
  			WARN(1, "mac802154: Packet is of unknown type %d\n",
  			     skb->pkt_type);
  			kfree_skb(skb);
  			break;
  		}
  	}
  }
  
  struct ieee802154_hw *
  ieee802154_alloc_hw(size_t priv_data_len, const struct ieee802154_ops *ops)
  {
  	struct wpan_phy *phy;
  	struct ieee802154_local *local;
  	size_t priv_size;
  
  	if (!ops || !(ops->xmit_async || ops->xmit_sync) || !ops->ed ||
  	    !ops->start || !ops->stop || !ops->set_channel) {
  		pr_err("undefined IEEE802.15.4 device operations\n");
  		return NULL;
  	}
  
  	/* Ensure 32-byte alignment of our private data and hw private data.
  	 * We use the wpan_phy priv data for both our ieee802154_local and for
  	 * the driver's private data
  	 *
  	 * in memory it'll be like this:
  	 *
  	 * +-------------------------+
  	 * | struct wpan_phy         |
  	 * +-------------------------+
  	 * | struct ieee802154_local |
  	 * +-------------------------+
  	 * | driver's private data   |
  	 * +-------------------------+
  	 *
  	 * Due to ieee802154 layer isn't aware of driver and MAC structures,
  	 * so lets align them here.
  	 */
  
  	priv_size = ALIGN(sizeof(*local), NETDEV_ALIGN) + priv_data_len;
  
  	phy = wpan_phy_new(&mac802154_config_ops, priv_size);
  	if (!phy) {
  		pr_err("failure to allocate master IEEE802.15.4 device\n");
  		return NULL;
  	}
  
  	phy->privid = mac802154_wpan_phy_privid;
  
  	local = wpan_phy_priv(phy);
  	local->phy = phy;
  	local->hw.phy = local->phy;
  	local->hw.priv = (char *)local + ALIGN(sizeof(*local), NETDEV_ALIGN);
  	local->ops = ops;
  
  	INIT_LIST_HEAD(&local->interfaces);
  	mutex_init(&local->iflist_mtx);
  
  	tasklet_init(&local->tasklet,
  		     ieee802154_tasklet_handler,
  		     (unsigned long)local);
  
  	skb_queue_head_init(&local->skb_queue);
  
  	/* init supported flags with 802.15.4 default ranges */
  	phy->supported.max_minbe = 8;
  	phy->supported.min_maxbe = 3;
  	phy->supported.max_maxbe = 8;
  	phy->supported.min_frame_retries = -1;
  	phy->supported.max_frame_retries = 7;
  	phy->supported.max_csma_backoffs = 5;
  	phy->supported.lbt = NL802154_SUPPORTED_BOOL_FALSE;
  
  	/* always supported */
  	phy->supported.iftypes = BIT(NL802154_IFTYPE_NODE);
  
  	return &local->hw;
  }
  EXPORT_SYMBOL(ieee802154_alloc_hw);
  
  void ieee802154_free_hw(struct ieee802154_hw *hw)
  {
  	struct ieee802154_local *local = hw_to_local(hw);
  
  	BUG_ON(!list_empty(&local->interfaces));
  
  	mutex_destroy(&local->iflist_mtx);
  
  	wpan_phy_free(local->phy);
  }
  EXPORT_SYMBOL(ieee802154_free_hw);
  
  static void ieee802154_setup_wpan_phy_pib(struct wpan_phy *wpan_phy)
  {
  	/* TODO warn on empty symbol_duration
  	 * Should be done when all drivers sets this value.
  	 */
  
  	wpan_phy->lifs_period = IEEE802154_LIFS_PERIOD *
  				wpan_phy->symbol_duration;
  	wpan_phy->sifs_period = IEEE802154_SIFS_PERIOD *
  				wpan_phy->symbol_duration;
  }
  
  int ieee802154_register_hw(struct ieee802154_hw *hw)
  {
  	struct ieee802154_local *local = hw_to_local(hw);
  	struct net_device *dev;
  	int rc = -ENOSYS;
  
  	local->workqueue =
  		create_singlethread_workqueue(wpan_phy_name(local->phy));
  	if (!local->workqueue) {
  		rc = -ENOMEM;
  		goto out;
  	}
  
  	hrtimer_init(&local->ifs_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
  	local->ifs_timer.function = ieee802154_xmit_ifs_timer;
  
  	wpan_phy_set_dev(local->phy, local->hw.parent);
  
  	ieee802154_setup_wpan_phy_pib(local->phy);
  
  	if (!(hw->flags & IEEE802154_HW_CSMA_PARAMS)) {
  		local->phy->supported.min_csma_backoffs = 4;
  		local->phy->supported.max_csma_backoffs = 4;
  		local->phy->supported.min_maxbe = 5;
  		local->phy->supported.max_maxbe = 5;
  		local->phy->supported.min_minbe = 3;
  		local->phy->supported.max_minbe = 3;
  	}
  
  	if (!(hw->flags & IEEE802154_HW_FRAME_RETRIES)) {
  		/* TODO should be 3, but our default value is -1 which means
  		 * no ARET handling.
  		 */
  		local->phy->supported.min_frame_retries = -1;
  		local->phy->supported.max_frame_retries = -1;
  	}
  
  	if (hw->flags & IEEE802154_HW_PROMISCUOUS)
  		local->phy->supported.iftypes |= BIT(NL802154_IFTYPE_MONITOR);
  
  	rc = wpan_phy_register(local->phy);
  	if (rc < 0)
  		goto out_wq;
  
  	rtnl_lock();
  
  	dev = ieee802154_if_add(local, "wpan%d", NET_NAME_ENUM,
  				NL802154_IFTYPE_NODE,
  				cpu_to_le64(0x0000000000000000ULL));
  	if (IS_ERR(dev)) {
  		rtnl_unlock();
  		rc = PTR_ERR(dev);
  		goto out_phy;
  	}
  
  	rtnl_unlock();
  
  	return 0;
  
  out_phy:
  	wpan_phy_unregister(local->phy);
  out_wq:
  	destroy_workqueue(local->workqueue);
  out:
  	return rc;
  }
  EXPORT_SYMBOL(ieee802154_register_hw);
  
  void ieee802154_unregister_hw(struct ieee802154_hw *hw)
  {
  	struct ieee802154_local *local = hw_to_local(hw);
  
  	tasklet_kill(&local->tasklet);
  	flush_workqueue(local->workqueue);
  	destroy_workqueue(local->workqueue);
  
  	rtnl_lock();
  
  	ieee802154_remove_interfaces(local);
  
  	rtnl_unlock();
  
  	wpan_phy_unregister(local->phy);
  }
  EXPORT_SYMBOL(ieee802154_unregister_hw);
  
  static int __init ieee802154_init(void)
  {
  	return ieee802154_iface_init();
  }
  
  static void __exit ieee802154_exit(void)
  {
  	ieee802154_iface_exit();
  
  	rcu_barrier();
  }
  
  subsys_initcall(ieee802154_init);
  module_exit(ieee802154_exit);
  
  MODULE_DESCRIPTION("IEEE 802.15.4 subsystem");
  MODULE_LICENSE("GPL v2");
  