/*
   * Linux WiMAX
   * Implement and export a method for resetting a WiMAX device
   *
   *
   * Copyright (C) 2008 Intel Corporation <linux-wimax@intel.com>
   * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.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.
   *
   * 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.
   *
   *
   * This implements a simple synchronous call to reset a WiMAX device.
   *
   * Resets aim at being warm, keeping the device handles active;
   * however, when that fails, it falls back to a cold reset (that will
   * disconnect and reconnect the device).
   */
  
  #include <net/wimax.h>
  #include <net/genetlink.h>
  #include <linux/wimax.h>
  #include <linux/security.h>
  #include <linux/export.h>
  #include "wimax-internal.h"
  
  #define D_SUBMODULE op_reset
  #include "debug-levels.h"
  
  
  /**
   * wimax_reset - Reset a WiMAX device
   *
   * @wimax_dev: WiMAX device descriptor
   *
   * Returns:
   *
   * %0 if ok and a warm reset was done (the device still exists in
   * the system).
   *
   * -%ENODEV if a cold/bus reset had to be done (device has
   * disconnected and reconnected, so current handle is not valid
   * any more).
   *
   * -%EINVAL if the device is not even registered.
   *
   * Any other negative error code shall be considered as
   * non-recoverable.
   *
   * Description:
   *
   * Called when wanting to reset the device for any reason. Device is
   * taken back to power on status.
   *
   * This call blocks; on successful return, the device has completed the
   * reset process and is ready to operate.
   */
  int wimax_reset(struct wimax_dev *wimax_dev)
  {
  	int result = -EINVAL;
  	struct device *dev = wimax_dev_to_dev(wimax_dev);
  	enum wimax_st state;
  
  	might_sleep();
  	d_fnstart(3, dev, "(wimax_dev %p)
  ", wimax_dev);
  	mutex_lock(&wimax_dev->mutex);
  	dev_hold(wimax_dev->net_dev);
  	state = wimax_dev->state;
  	mutex_unlock(&wimax_dev->mutex);
  
  	if (state >= WIMAX_ST_DOWN) {
  		mutex_lock(&wimax_dev->mutex_reset);
  		result = wimax_dev->op_reset(wimax_dev);
  		mutex_unlock(&wimax_dev->mutex_reset);
  	}
  	dev_put(wimax_dev->net_dev);
  
  	d_fnend(3, dev, "(wimax_dev %p) = %d
  ", wimax_dev, result);
  	return result;
  }
  EXPORT_SYMBOL(wimax_reset);
  
  
  /*
   * Exporting to user space over generic netlink
   *
   * Parse the reset command from user space, return error code.
   *
   * No attributes.
   */
  int wimax_gnl_doit_reset(struct sk_buff *skb, struct genl_info *info)
  {
  	int result, ifindex;
  	struct wimax_dev *wimax_dev;
  
  	d_fnstart(3, NULL, "(skb %p info %p)
  ", skb, info);
  	result = -ENODEV;
  	if (info->attrs[WIMAX_GNL_RESET_IFIDX] == NULL) {
  		printk(KERN_ERR "WIMAX_GNL_OP_RFKILL: can't find IFIDX "
  			"attribute
  ");
  		goto error_no_wimax_dev;
  	}
  	ifindex = nla_get_u32(info->attrs[WIMAX_GNL_RESET_IFIDX]);
  	wimax_dev = wimax_dev_get_by_genl_info(info, ifindex);
  	if (wimax_dev == NULL)
  		goto error_no_wimax_dev;
  	/* Execute the operation and send the result back to user space */
  	result = wimax_reset(wimax_dev);
  	dev_put(wimax_dev->net_dev);
  error_no_wimax_dev:
  	d_fnend(3, NULL, "(skb %p info %p) = %d
  ", skb, info, result);
  	return result;
  }