/*
   * UWB PAL support.
   *
   * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
   *
   * 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, see <http://www.gnu.org/licenses/>.
   */
  #include <linux/kernel.h>

  #include <linux/debugfs.h>

  #include <linux/uwb.h>

  #include <linux/export.h>

  
  #include "uwb-internal.h"
  
  /**
   * uwb_pal_init - initialize a UWB PAL
   * @pal: the PAL to initialize
   */
  void uwb_pal_init(struct uwb_pal *pal)
  {
  	INIT_LIST_HEAD(&pal->node);
  }
  EXPORT_SYMBOL_GPL(uwb_pal_init);
  
  /**
   * uwb_pal_register - register a UWB PAL

   * @pal: the PAL
   *
   * The PAL must be initialized with uwb_pal_init().
   */

  int uwb_pal_register(struct uwb_pal *pal)

  {

  	struct uwb_rc *rc = pal->rc;

  	int ret;
  
  	if (pal->device) {

  		/* create a link to the uwb_rc in the PAL device's directory. */

  		ret = sysfs_create_link(&pal->device->kobj,
  					&rc->uwb_dev.dev.kobj, "uwb_rc");
  		if (ret < 0)
  			return ret;

  		/* create a link to the PAL in the UWB device's directory. */

  		ret = sysfs_create_link(&rc->uwb_dev.dev.kobj,
  					&pal->device->kobj, pal->name);
  		if (ret < 0) {
  			sysfs_remove_link(&pal->device->kobj, "uwb_rc");
  			return ret;
  		}
  	}

  	pal->debugfs_dir = uwb_dbg_create_pal_dir(pal);

  	mutex_lock(&rc->uwb_dev.mutex);

  	list_add(&pal->node, &rc->pals);

  	mutex_unlock(&rc->uwb_dev.mutex);

  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(uwb_pal_register);

  static int find_rc(struct device *dev, const void *data)
  {
  	const struct uwb_rc *target_rc = data;
  	struct uwb_rc *rc = dev_get_drvdata(dev);
  
  	if (rc == NULL) {
  		WARN_ON(1);
  		return 0;
  	}
  	if (rc == target_rc) {
  		if (rc->ready == 0)
  			return 0;
  		else
  			return 1;
  	}
  	return 0;
  }
  
  /**
   * Given a radio controller descriptor see if it is registered.
   *
   * @returns false if the rc does not exist or is quiescing; true otherwise.
   */
  static bool uwb_rc_class_device_exists(struct uwb_rc *target_rc)
  {
  	struct device *dev;
  
  	dev = class_find_device(&uwb_rc_class, NULL, target_rc,	find_rc);
  
  	return (dev != NULL);
  }

  /**

   * uwb_pal_unregister - unregister a UWB PAL

   * @pal: the PAL
   */

  void uwb_pal_unregister(struct uwb_pal *pal)

  {

  	struct uwb_rc *rc = pal->rc;
  
  	uwb_radio_stop(pal);
  
  	mutex_lock(&rc->uwb_dev.mutex);

  	list_del(&pal->node);

  	mutex_unlock(&rc->uwb_dev.mutex);

  	debugfs_remove(pal->debugfs_dir);

  	if (pal->device) {

  		/* remove link to the PAL in the UWB device's directory. */
  		if (uwb_rc_class_device_exists(rc))
  			sysfs_remove_link(&rc->uwb_dev.dev.kobj, pal->name);
  
  		/* remove link to uwb_rc in the PAL device's directory. */

  		sysfs_remove_link(&pal->device->kobj, "uwb_rc");
  	}

  }
  EXPORT_SYMBOL_GPL(uwb_pal_unregister);
  
  /**
   * uwb_rc_pal_init - initialize the PAL related parts of a radio controller
   * @rc: the radio controller
   */
  void uwb_rc_pal_init(struct uwb_rc *rc)
  {

  	INIT_LIST_HEAD(&rc->pals);
  }