/*
   * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
   *
   * 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.
   *
   * Based on minstrel.c:
   *   Copyright (C) 2005-2007 Derek Smithies <derek@indranet.co.nz>
   *   Sponsored by Indranet Technologies Ltd
   *
   * Based on sample.c:
   *   Copyright (c) 2005 John Bicket
   *   All rights reserved.
   *
   *   Redistribution and use in source and binary forms, with or without
   *   modification, are permitted provided that the following conditions
   *   are met:
   *   1. Redistributions of source code must retain the above copyright
   *      notice, this list of conditions and the following disclaimer,
   *      without modification.
   *   2. Redistributions in binary form must reproduce at minimum a disclaimer
   *      similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
   *      redistribution must be conditioned upon including a substantially
   *      similar Disclaimer requirement for further binary redistribution.
   *   3. Neither the names of the above-listed copyright holders nor the names
   *      of any contributors may be used to endorse or promote products derived
   *      from this software without specific prior written permission.
   *
   *   Alternatively, this software may be distributed under the terms of the
   *   GNU General Public License ("GPL") version 2 as published by the Free
   *   Software Foundation.
   *
   *   NO WARRANTY
   *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   *   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   *   LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
   *   AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
   *   THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
   *   OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   *   SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
   *   IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   *   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
   *   THE POSSIBILITY OF SUCH DAMAGES.
   */
  #include <linux/netdevice.h>
  #include <linux/types.h>
  #include <linux/skbuff.h>
  #include <linux/debugfs.h>
  #include <linux/ieee80211.h>

  #include <linux/slab.h>

  #include <linux/export.h>

  #include <net/mac80211.h>
  #include "rc80211_minstrel.h"

  int

  minstrel_stats_open(struct inode *inode, struct file *file)
  {
  	struct minstrel_sta_info *mi = inode->i_private;

  	struct minstrel_debugfs_info *ms;

  	unsigned int i, tp, prob, eprob;
  	char *p;

  	ms = kmalloc(sizeof(*ms) + 4096, GFP_KERNEL);

  	if (!ms)
  		return -ENOMEM;
  
  	file->private_data = ms;
  	p = ms->buf;
  	p += sprintf(p, "rate     throughput  ewma prob   this prob  "
  			"this succ/attempt   success    attempts
  ");
  	for (i = 0; i < mi->n_rates; i++) {
  		struct minstrel_rate *mr = &mi->r[i];
  
  		*(p++) = (i == mi->max_tp_rate) ? 'T' : ' ';
  		*(p++) = (i == mi->max_tp_rate2) ? 't' : ' ';
  		*(p++) = (i == mi->max_prob_rate) ? 'P' : ' ';
  		p += sprintf(p, "%3u%s", mr->bitrate / 2,
  				(mr->bitrate & 1 ? ".5" : "  "));

  		tp = mr->cur_tp / ((18000 << 10) / 96);

  		prob = mr->cur_prob / 18;
  		eprob = mr->probability / 18;
  
  		p += sprintf(p, "  %6u.%1u   %6u.%1u   %6u.%1u        "
  				"%3u(%3u)   %8llu    %8llu
  ",
  				tp / 10, tp % 10,
  				eprob / 10, eprob % 10,
  				prob / 10, prob % 10,
  				mr->last_success,
  				mr->last_attempts,

  				(unsigned long long)mr->succ_hist,
  				(unsigned long long)mr->att_hist);

  	}
  	p += sprintf(p, "
  Total packet count::    ideal %d      "
  			"lookaround %d
  
  ",
  			mi->packet_count - mi->sample_count,
  			mi->sample_count);
  	ms->len = p - ms->buf;
  
  	return 0;
  }

  ssize_t

  minstrel_stats_read(struct file *file, char __user *buf, size_t len, loff_t *ppos)

  {

  	struct minstrel_debugfs_info *ms;

  
  	ms = file->private_data;

  	return simple_read_from_buffer(buf, len, ppos, ms->buf, ms->len);

  }

  int

  minstrel_stats_release(struct inode *inode, struct file *file)
  {

  	kfree(file->private_data);

  	return 0;
  }

  static const struct file_operations minstrel_stat_fops = {

  	.owner = THIS_MODULE,
  	.open = minstrel_stats_open,
  	.read = minstrel_stats_read,
  	.release = minstrel_stats_release,

  	.llseek = default_llseek,

  };
  
  void
  minstrel_add_sta_debugfs(void *priv, void *priv_sta, struct dentry *dir)
  {
  	struct minstrel_sta_info *mi = priv_sta;
  
  	mi->dbg_stats = debugfs_create_file("rc_stats", S_IRUGO, dir, mi,
  			&minstrel_stat_fops);
  }
  
  void
  minstrel_remove_sta_debugfs(void *priv, void *priv_sta)
  {
  	struct minstrel_sta_info *mi = priv_sta;
  
  	debugfs_remove(mi->dbg_stats);
  }