/*
   * Copyright (C) 2007, 2008, 2009 Siemens AG
   *
   * 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.
   *
   * 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.,
   * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   */

  #include <linux/slab.h>

  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/device.h>
  
  #include <net/wpan-phy.h>

  #include "ieee802154.h"

  #define MASTER_SHOW_COMPLEX(name, format_string, args...)		\
  static ssize_t name ## _show(struct device *dev,			\
  			    struct device_attribute *attr, char *buf)	\
  {									\
  	struct wpan_phy *phy = container_of(dev, struct wpan_phy, dev);	\
  	int ret;							\
  									\
  	mutex_lock(&phy->pib_lock);					\

  	ret = snprintf(buf, PAGE_SIZE, format_string "
  ", args);	\

  	mutex_unlock(&phy->pib_lock);					\
  	return ret;							\
  }
  
  #define MASTER_SHOW(field, format_string)				\
  	MASTER_SHOW_COMPLEX(field, format_string, phy->field)
  
  MASTER_SHOW(current_channel, "%d");
  MASTER_SHOW(current_page, "%d");

  MASTER_SHOW_COMPLEX(transmit_power, "%d +- %d dB",
  	((signed char) (phy->transmit_power << 2)) >> 2,
  	(phy->transmit_power >> 6) ? (phy->transmit_power >> 6) * 3 : 1 );
  MASTER_SHOW(cca_mode, "%d");

  static ssize_t channels_supported_show(struct device *dev,
  			    struct device_attribute *attr, char *buf)
  {
  	struct wpan_phy *phy = container_of(dev, struct wpan_phy, dev);
  	int ret;
  	int i, len = 0;
  
  	mutex_lock(&phy->pib_lock);
  	for (i = 0; i < 32; i++) {
  		ret = snprintf(buf + len, PAGE_SIZE - len,
  				"%#09x
  ", phy->channels_supported[i]);
  		if (ret < 0)
  			break;
  		len += ret;
  	}
  	mutex_unlock(&phy->pib_lock);
  	return len;
  }

  static struct device_attribute pmib_attrs[] = {
  	__ATTR_RO(current_channel),
  	__ATTR_RO(current_page),
  	__ATTR_RO(channels_supported),
  	__ATTR_RO(transmit_power),
  	__ATTR_RO(cca_mode),
  	{},
  };
  
  static void wpan_phy_release(struct device *d)
  {
  	struct wpan_phy *phy = container_of(d, struct wpan_phy, dev);
  	kfree(phy);
  }
  
  static struct class wpan_phy_class = {
  	.name = "ieee802154",
  	.dev_release = wpan_phy_release,
  	.dev_attrs = pmib_attrs,
  };
  
  static DEFINE_MUTEX(wpan_phy_mutex);
  static int wpan_phy_idx;
  
  static int wpan_phy_match(struct device *dev, void *data)
  {
  	return !strcmp(dev_name(dev), (const char *)data);
  }
  
  struct wpan_phy *wpan_phy_find(const char *str)
  {
  	struct device *dev;
  
  	if (WARN_ON(!str))
  		return NULL;
  
  	dev = class_find_device(&wpan_phy_class, NULL,
  			(void *)str, wpan_phy_match);
  	if (!dev)
  		return NULL;
  
  	return container_of(dev, struct wpan_phy, dev);
  }
  EXPORT_SYMBOL(wpan_phy_find);

  struct wpan_phy_iter_data {
  	int (*fn)(struct wpan_phy *phy, void *data);
  	void *data;
  };
  
  static int wpan_phy_iter(struct device *dev, void *_data)
  {
  	struct wpan_phy_iter_data *wpid = _data;
  	struct wpan_phy *phy = container_of(dev, struct wpan_phy, dev);
  	return wpid->fn(phy, wpid->data);
  }
  
  int wpan_phy_for_each(int (*fn)(struct wpan_phy *phy, void *data),
  		void *data)
  {
  	struct wpan_phy_iter_data wpid = {
  		.fn = fn,
  		.data = data,
  	};
  
  	return class_for_each_device(&wpan_phy_class, NULL,
  			&wpid, wpan_phy_iter);
  }
  EXPORT_SYMBOL(wpan_phy_for_each);

  static int wpan_phy_idx_valid(int idx)
  {
  	return idx >= 0;
  }
  
  struct wpan_phy *wpan_phy_alloc(size_t priv_size)
  {
  	struct wpan_phy *phy = kzalloc(sizeof(*phy) + priv_size,
  			GFP_KERNEL);

  	if (!phy)
  		goto out;

  	mutex_lock(&wpan_phy_mutex);
  	phy->idx = wpan_phy_idx++;
  	if (unlikely(!wpan_phy_idx_valid(phy->idx))) {
  		wpan_phy_idx--;
  		mutex_unlock(&wpan_phy_mutex);
  		kfree(phy);

  		goto out;

  	}
  	mutex_unlock(&wpan_phy_mutex);
  
  	mutex_init(&phy->pib_lock);
  
  	device_initialize(&phy->dev);
  	dev_set_name(&phy->dev, "wpan-phy%d", phy->idx);
  
  	phy->dev.class = &wpan_phy_class;

  	phy->current_channel = -1; /* not initialised */
  	phy->current_page = 0; /* for compatibility */

  	return phy;

  
  out:
  	return NULL;

  }
  EXPORT_SYMBOL(wpan_phy_alloc);

  int wpan_phy_register(struct wpan_phy *phy)

  {

  	return device_add(&phy->dev);
  }
  EXPORT_SYMBOL(wpan_phy_register);
  
  void wpan_phy_unregister(struct wpan_phy *phy)
  {
  	device_del(&phy->dev);
  }
  EXPORT_SYMBOL(wpan_phy_unregister);
  
  void wpan_phy_free(struct wpan_phy *phy)
  {
  	put_device(&phy->dev);
  }
  EXPORT_SYMBOL(wpan_phy_free);
  
  static int __init wpan_phy_class_init(void)
  {

  	int rc;
  	rc = class_register(&wpan_phy_class);
  	if (rc)
  		goto err;
  
  	rc = ieee802154_nl_init();
  	if (rc)
  		goto err_nl;
  
  	return 0;
  err_nl:
  	class_unregister(&wpan_phy_class);
  err:
  	return rc;

  }

  subsys_initcall(wpan_phy_class_init);

  
  static void __exit wpan_phy_class_exit(void)
  {

  	ieee802154_nl_exit();

  	class_unregister(&wpan_phy_class);
  }
  module_exit(wpan_phy_class_exit);

  MODULE_LICENSE("GPL v2");

  MODULE_DESCRIPTION("IEEE 802.15.4 configuration interface");
  MODULE_AUTHOR("Dmitry Eremin-Solenikov");