path: root/drivers/net/wireless/iwlwifi/iwl-3945-rs.c

/******************************************************************************
 *
 * Copyright(c) 2005 - 2008 Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2 of the GNU General Public License 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, USA
 *
 * The full GNU General Public License is included in this distribution in the
 * file called LICENSE.
 *
 * Contact Information:
 *  Intel Linux Wireless <ilw@linux.intel.com>
 * Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
 *
 *****************************************************************************/

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/skbuff.h>
#include <linux/wireless.h>
#include <net/mac80211.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/delay.h>

#include <linux/workqueue.h>

#include "iwl-commands.h"
#include "iwl-3945.h"

#define RS_NAME "iwl-3945-rs"

struct iwl3945_rate_scale_data {
	u64 data;
	s32 success_counter;
	s32 success_ratio;
	s32 counter;
	s32 average_tpt;
	unsigned long stamp;
};

struct iwl3945_rs_sta {
	spinlock_t lock;
	struct iwl3945_priv *priv;
	s32 *expected_tpt;
	unsigned long last_partial_flush;
	unsigned long last_flush;
	u32 flush_time;
	u32 last_tx_packets;
	u32 tx_packets;
	u8 tgg;
	u8 flush_pending;
	u8 start_rate;
	u8 ibss_sta_added;
	struct timer_list rate_scale_flush;
	struct iwl3945_rate_scale_data win[IWL_RATE_COUNT_3945];
#ifdef CONFIG_MAC80211_DEBUGFS
	struct dentry *rs_sta_dbgfs_stats_table_file;
#endif

	/* used to be in sta_info */
	int last_txrate_idx;
};

static s32 iwl3945_expected_tpt_g[IWL_RATE_COUNT_3945] = {
	7, 13, 35, 58, 0, 0, 76, 104, 130, 168, 191, 202
};

static s32 iwl3945_expected_tpt_g_prot[IWL_RATE_COUNT_3945] = {
	7, 13, 35, 58, 0, 0, 0, 80, 93, 113, 123, 125
};

static s32 iwl3945_expected_tpt_a[IWL_RATE_COUNT_3945] = {
	0, 0, 0, 0, 40, 57, 72, 98, 121, 154, 177, 186
};

static s32 iwl3945_expected_tpt_b[IWL_RATE_COUNT_3945] = {
	7, 13, 35, 58, 0, 0, 0, 0, 0, 0, 0, 0
};

struct iwl3945_tpt_entry {
	s8 min_rssi;
	u8 index;
};

static struct iwl3945_tpt_entry iwl3945_tpt_table_a[] = {
	{-60, IWL_RATE_54M_INDEX},
	{-64, IWL_RATE_48M_INDEX},
	{-72, IWL_RATE_36M_INDEX},
	{-80, IWL_RATE_24M_INDEX},
	{-84, IWL_RATE_18M_INDEX},
	{-85, IWL_RATE_12M_INDEX},
	{-87, IWL_RATE_9M_INDEX},
	{-89, IWL_RATE_6M_INDEX}
};

static struct iwl3945_tpt_entry iwl3945_tpt_table_g[] = {
	{-60, IWL_RATE_54M_INDEX},
	{-64, IWL_RATE_48M_INDEX},
	{-68, IWL_RATE_36M_INDEX},
	{-80, IWL_RATE_24M_INDEX},
	{-84, IWL_RATE_18M_INDEX},
	{-85, IWL_RATE_12M_INDEX},
	{-86, IWL_RATE_11M_INDEX},
	{-88, IWL_RATE_5M_INDEX},
	{-90, IWL_RATE_2M_INDEX},
	{-92, IWL_RATE_1M_INDEX}
};

#define IWL_RATE_MAX_WINDOW          62
#define IWL_RATE_FLUSH       	 (3*HZ)
#define IWL_RATE_WIN_FLUSH       (HZ/2)
#define IWL39_RATE_HIGH_TH          11520
#define IWL_SUCCESS_UP_TH	   8960
#define IWL_SUCCESS_DOWN_TH	  10880
#define IWL_RATE_MIN_FAILURE_TH       8
#define IWL_RATE_MIN_SUCCESS_TH       8
#define IWL_RATE_DECREASE_TH       1920

static u8 iwl3945_get_rate_index_by_rssi(s32 rssi, enum ieee80211_band band)
{
	u32 index = 0;
	u32 table_size = 0;
	struct iwl3945_tpt_entry *tpt_table = NULL;

	if ((rssi < IWL_MIN_RSSI_VAL) || (rssi > IWL_MAX_RSSI_VAL))
		rssi = IWL_MIN_RSSI_VAL;

	switch (band) {
	case IEEE80211_BAND_2GHZ:
		tpt_table = iwl3945_tpt_table_g;
		table_size = ARRAY_SIZE(iwl3945_tpt_table_g);
		break;

	case IEEE80211_BAND_5GHZ:
		tpt_table = iwl3945_tpt_table_a;
		table_size = ARRAY_SIZE(iwl3945_tpt_table_a);
		break;

	default:
		BUG();
		break;
	}

	while ((index < table_size) && (rssi < tpt_table[index].min_rssi))
		index++;

	index = min(index, (table_size - 1));

	return tpt_table[index].index;
}

static void iwl3945_clear_window(struct iwl3945_rate_scale_data *window)
{
	window->data = 0;
	window->success_counter = 0;
	window->success_ratio = -1;
	window->counter = 0;
	window->average_tpt = IWL_INVALID_VALUE;
	window->stamp = 0;
}

/**
 *