[deliverable/linux.git] / drivers / net / wireless / rt2x00 / rt2x00link.c

/*
	Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
	<http://rt2x00.serialmonkey.com>

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	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.,
	59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*
	Module: rt2x00lib
	Abstract: rt2x00 generic link tuning routines.
 */

#include <linux/kernel.h>
#include <linux/module.h>

#include "rt2x00.h"
#include "rt2x00lib.h"

/*
 * When we lack RSSI information return something less then -80 to
 * tell the driver to tune the device to maximum sensitivity.
 */
#define DEFAULT_RSSI		-128

/* Constants for EWMA calculations. */
#define RT2X00_EWMA_FACTOR	1024
#define RT2X00_EWMA_WEIGHT	8

static inline int rt2x00link_get_avg_rssi(struct ewma *ewma)
{
	unsigned long avg;

	avg = ewma_read(ewma);
	if (avg)
		return -avg;

	return DEFAULT_RSSI;
}

static int rt2x00link_antenna_get_link_rssi(struct rt2x00_dev *rt2x00dev)
{
	struct link_ant *ant = &rt2x00dev->link.ant;

	if (rt2x00dev->link.qual.rx_success)
		return rt2x00link_get_avg_rssi(&ant->rssi_ant);

	return DEFAULT_RSSI;
}

static int rt2x00link_antenna_get_rssi_history(struct rt2x00_dev *rt2x00dev)
{
	struct link_ant *ant = &rt2x00dev->link.ant;

	if (ant->rssi_history)
		return ant->rssi_history;
	return DEFAULT_RSSI;
}

static void rt2x00link_antenna_update_rssi_history(struct rt2x00_dev *rt2x00dev,
						   int rssi)
{
	struct link_ant *ant = &rt2x00dev->link.ant;
	ant->rssi_history = rssi;
}

static void rt2x00link_antenna_reset(struct rt2x00_dev *rt2x00dev)
{
	ewma_init(&rt2x00dev->link.ant.rssi_ant, RT2X00_EWMA_FACTOR,
		  RT2X00_EWMA_WEIGHT);
}

static void rt2x00lib_antenna_diversity_sample(struct rt2x00_dev *rt2x00dev)
{
	struct link_ant *ant = &rt2x00dev->link.ant;
	struct antenna_setup new_ant;
	int other_antenna;

	int sample_current = rt2x00link_antenna_get_link_rssi(rt2x00dev);
	int sample_other = rt2x00link_antenna_get_rssi_history(rt2x00dev);

	memcpy(&new_ant, &ant->active, sizeof(new_ant));

	/*
	 * We are done sampling. Now we should evaluate the results.
	 */
	ant->flags &= ~ANTENNA_MODE_SAMPLE;

	/*
	 * During the last period we have sampled the RSSI
	 * from both antennas. It now is time to determine
	 * which antenna demonstrated the best performance.
	 * When we are already on the antenna with the best
	 * performance, just create a good starting point
	 * for the history and we are done.
	 */
	if (sample_current >= sample_other) {
		rt2x00link_antenna_update_rssi_history(rt2x00dev,
			sample_current);
		return;
	}

	other_antenna = (ant->active.rx == ANTENNA_A) ? ANTENNA_B : ANTENNA_A;

	if (ant->flags & ANTENNA_RX_DIVERSITY)
		new_ant.rx = other_antenna;

	if (ant->flags & ANTENNA_TX_DIVERSITY)
		new_ant.tx = other_antenna;

	rt2x00lib_config_antenna(rt2x00dev, new_ant);
}

static void rt2x00lib_antenna_diversity_eval(struct rt2x00_dev *rt2x00dev)
{
	struct link_ant *ant = &rt2x00dev->link.ant;
	struct antenna_setup new_ant;
	int rssi_curr;
	int rssi_old;

	memcpy(&new_ant, &ant->active, sizeof(new_ant));

	/*
	 * Get current RSSI value along with the historical value,
	 * after that update the history with the current value.
	 */
	rssi_curr = rt2x00link_antenna_get_link_rssi(rt2x00dev);
	rssi_old = rt2x00link_antenna_get_rssi_history(rt2x00dev);
	rt2x00link_antenna_update_rssi_history(rt2x00dev, rssi_curr);

	/*
	 * Legacy driver indicates that we should swap antenna's
	 * when the difference in RSSI is greater that 5. This
	 * also should be done when the RSSI was actually better
	 * then the previous sample.
	 * When the difference exceeds the threshold we should
	 * sample the rssi from the other antenna to make a valid
	 * comparison between the 2 antennas.
	 */
	if (abs(rssi_curr - rssi_old) < 5)
		return;

	ant->flags |= ANTENNA_MODE_SAMPLE;

	if (ant->flags & ANTENNA_RX_DIVERSITY)
		new_ant.rx = (new_ant.rx == ANTENNA_A) ? ANTENNA_B : ANTENNA_A;

	if (ant->flags & ANTENNA_TX_DIVERSITY)
		new_ant.tx = (new_ant.tx == ANTENNA_A) ? ANTENNA_B : ANTENNA_A;

	rt2x00lib_config_antenna(rt2x00dev, new_ant);
}

static bool rt2x00lib_antenna_diversity(struct rt2x00_dev *rt2x00dev)
{
	struct link_ant *ant = &rt2x00dev->link.ant;

	/*
	 * Determine if software diversity is enabled for
	 * either the TX or RX antenna (or both).
	 */
	if (!(ant->flags & ANTENNA_RX_DIVERSITY) &&
	    !(ant->flags & ANTENNA_TX_DIVERSITY)) {
		ant->flags = 0;
		return true;
	}

	/*
	 * If we have only sampled the data over the last period
	 * we should now harvest the data. Otherwise just evaluate
	 * the data. The latter should only be performed once
	 * every 2 seconds.
	 */
	if (ant->flags & ANTENNA_MODE_SAMPLE) {
		rt2x00lib_antenna_diversity_sample(rt2x00dev);
		return true;
	} else if (rt2x00dev->link.count & 1) {
		rt2x00lib_antenna_diversity_eval(rt2x00dev);
		return true;
	}

	return false;
}

void rt2x00link_update_stats(struct rt2x00_dev *rt2x00dev,
			     struct sk_buff *skb,
			     struct rxdone_entry_desc *rxdesc)
{
	struct link *link = &rt2x00dev->link;
	struct link_qual *qual = &rt2x00dev->link.qual;
	struct link_ant *ant = &rt2x00dev->link.ant;
	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;

	/*
	 * No need to update the stats for !=STA interfaces
	 */
	if (!rt2x00dev->intf_sta_count)
		return;

	/*
	 * Frame was received successfully since non-succesfull
	 * frames would have been dropped by the hardware.
	 */
	qual->rx_success++;

	/*
	 * We are only interested in quality statistics from
	 * beacons which came from the BSS which we are
	 * associated with.
	 */
	if (!ieee80211_is_beacon(hdr->frame_control) ||
	    !(rxdesc->dev_flags & RXDONE_MY_BSS))
		return;

	/*
	 * Update global RSSI
	 */
	ewma_add(&link->avg_rssi, -rxdesc->rssi);

	/*
	 * Update antenna RSSI
	 */
	ewma_add(&ant->rssi_ant, -rxdesc->rssi);
}

void rt2x00link_start_tuner(struct rt2x00_dev *rt2x00dev)
{
	struct link *link = &rt2x00dev->link;

	/*
	 * Link tuning should only be performed when
	 * an active sta interface exists. AP interfaces
	 * don't need link tuning and monitor mode interfaces
	 * should never have to work with link tuners.
	 */
	if (!rt2x00dev->intf_sta_count)
		return;

	/**
	 * While scanning, link tuning is disabled. By default
	 * the most sensitive settings will be used to make sure
	 * that all beacons and probe responses will be received
	 * during the scan.
	 */
	if (test_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags))
		return;

	rt2x00link_reset_tuner(rt2x00dev, false);

	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
		ieee80211_queue_delayed_work(rt2x00dev->hw,
					     &link->work, LINK_TUNE_INTERVAL);
}

void rt2x00link_stop_tuner(struct rt2x00_dev *rt2x00dev)
{
	cancel_delayed_work_sync(&rt2x00dev->link.work);
}

void rt2x00link_reset_tuner(struct rt2x00_dev *rt2x00dev, bool antenna)
{
	struct link_qual *qual = &rt2x00dev->link.qual;
	u8 vgc_level = qual->vgc_level_reg;

	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
		return;

	/*
	 * Reset link information.
	 * Both the currently active vgc level as well as
	 * the link tuner counter should be reset. Resetting
	 * the counter is important for devices where the
	 * device should only perform link tuning during the
	 * first minute after being enabled.
	 */
	rt2x00dev->link.count = 0;
	memset(qual, 0, sizeof(*qual));
	ewma_init(&rt2x00dev->link.avg_rssi, RT2X00_EWMA_FACTOR,
		  RT2X00_EWMA_WEIGHT);

	/*
	 * Restore the VGC level as stored in the registers,
	 * the driver can use this to determine if the register
	 * must be updated during reset or not.
	 */
	qual->vgc_level_reg = vgc_level;

	/*
	 * Reset the link tuner.
	 */
	rt2x00dev->ops->lib->reset_tuner(rt2x00dev, qual);

	if (antenna)
		rt2x00link_antenna_reset(rt2x00dev);
}

static void rt2x00link_reset_qual(struct rt2x00_dev *rt2x00dev)
{
	struct link_qual *qual = &rt2x00dev->link.qual;

	qual->rx_success = 0;
	qual->rx_failed = 0;
	qual->tx_success = 0;
	qual->tx_failed = 0;
}

static void rt2x00link_tuner(struct work_struct *work)
{
	struct rt2x00_dev *rt2x00dev =
	    container_of(work, struct rt2x00_dev, link.work.work);
	struct link *link = &rt2x00dev->link;
	struct link_qual *qual = &rt2x00dev->link.qual;

	/*
	 * When the radio is shutting down we should
	 * immediately cease all link tuning.
	 */
	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
	    test_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags))
		return;

	/*
	 * Update statistics.
	 */
	rt2x00dev->ops->lib->link_stats(rt2x00dev, qual);
	rt2x00dev->low_level_stats.dot11FCSErrorCount += qual->rx_failed;

	/*
	 * Update quality RSSI for link tuning,
	 * when we have received some frames and we managed to
	 * collect the RSSI data we could use this. Otherwise we
	 * must fallback to the default RSSI value.
	 */
	if (!qual->rx_success)
		qual->rssi = DEFAULT_RSSI;
	else
		qual->rssi = rt2x00link_get_avg_rssi(&link->avg_rssi);

	/*
	 * Check if link tuning is supported by the hardware, some hardware
	 * do not support link tuning at all, while other devices can disable
	 * the feature from the EEPROM.
	 */
	if (rt2x00_has_cap_link_tuning(rt2x00dev))
		rt2x00dev->ops->lib->link_tuner(rt2x00dev, qual, link->count);

	/*
	 * Send a signal to the led to update the led signal strength.
	 */
	rt2x00leds_led_quality(rt2x00dev, qual->rssi);

	/*
	 * Evaluate antenna setup, make this the last step when
	 * rt2x00lib_antenna_diversity made changes the quality
	 * statistics will be reset.
	 */
	if (rt2x00lib_antenna_diversity(rt2x00dev))
		rt2x00link_reset_qual(rt2x00dev);

	/*
	 * Increase tuner counter, and reschedule the next link tuner run.
	 */
	link->count++;

	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
		ieee80211_queue_delayed_work(rt2x00dev->hw,
					     &link->work, LINK_TUNE_INTERVAL);
}

void rt2x00link_start_watchdog(struct rt2x00_dev *rt2x00dev)
{
	struct link *link = &rt2x00dev->link;

	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
	    rt2x00dev->ops->lib->watchdog)
		ieee80211_queue_delayed_work(rt2x00dev->hw,
					     &link->watchdog_work,
					     WATCHDOG_INTERVAL);
}

void rt2x00link_stop_watchdog(struct rt2x00_dev *rt2x00dev)
{
	cancel_delayed_work_sync(&rt2x00dev->link.watchdog_work);
}

static void rt2x00link_watchdog(struct work_struct *work)
{
	struct rt2x00_dev *rt2x00dev =
	    container_of(work, struct rt2x00_dev, link.watchdog_work.work);
	struct link *link = &rt2x00dev->link;

	/*
	 * When the radio is shutting down we should
	 * immediately cease the watchdog monitoring.
	 */
	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
		return;

	rt2x00dev->ops->lib->watchdog(rt2x00dev);

	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
		ieee80211_queue_delayed_work(rt2x00dev->hw,
					     &link->watchdog_work,
					     WATCHDOG_INTERVAL);
}

void rt2x00link_start_agc(struct rt2x00_dev *rt2x00dev)
{
	struct link *link = &rt2x00dev->link;

	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
	    rt2x00dev->ops->lib->gain_calibration)
		ieee80211_queue_delayed_work(rt2x00dev->hw,
					     &link->agc_work,
					     AGC_INTERVAL);
}

void rt2x00link_start_vcocal(struct rt2x00_dev *rt2x00dev)
{
	struct link *link = &rt2x00dev->link;

	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
	    rt2x00dev->ops->lib->vco_calibration)
		ieee80211_queue_delayed_work(rt2x00dev->hw,
					     &link->vco_work,
					     VCO_INTERVAL);
}

void rt2x00link_stop_agc(struct rt2x00_dev *rt2x00dev)
{
	cancel_delayed_work_sync(&rt2x00dev->link.agc_work);
}

void rt2x00link_stop_vcocal(struct rt2x00_dev *rt2x00dev)
{
	cancel_delayed_work_sync(&rt2x00dev->link.vco_work);
}

static void rt2x00link_agc(struct work_struct *work)
{
	struct rt2x00_dev *rt2x00dev =
	    container_of(work, struct rt2x00_dev, link.agc_work.work);
	struct link *link = &rt2x00dev->link;

	/*
	 * When the radio is shutting down we should
	 * immediately cease the watchdog monitoring.
	 */
	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
		return;

	rt2x00dev->ops->lib->gain_calibration(rt2x00dev);

	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
		ieee80211_queue_delayed_work(rt2x00dev->hw,
					     &link->agc_work,
					     AGC_INTERVAL);
}

static void rt2x00link_vcocal(struct work_struct *work)
{
	struct rt2x00_dev *rt2x00dev =
	    container_of(work, struct rt2x00_dev, link.vco_work.work);
	struct link *link = &rt2x00dev->link;

	/*
	 * When the radio is shutting down we should
	 * immediately cease the VCO calibration.
	 */
	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
		return;

	rt2x00dev->ops->lib->vco_calibration(rt2x00dev);

	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
		ieee80211_queue_delayed_work(rt2x00dev->hw,
					     &link->vco_work,
					     VCO_INTERVAL);
}

void rt2x00link_register(struct rt2x00_dev *rt2x00dev)
{
	INIT_DELAYED_WORK(&rt2x00dev->link.agc_work, rt2x00link_agc);
	if (rt2x00_has_cap_vco_recalibration(rt2x00dev))
		INIT_DELAYED_WORK(&rt2x00dev->link.vco_work, rt2x00link_vcocal);
	INIT_DELAYED_WORK(&rt2x00dev->link.watchdog_work, rt2x00link_watchdog);
	INIT_DELAYED_WORK(&rt2x00dev->link.work, rt2x00link_tuner);
}
Commit	Line	Data
84e3196f	1	/*
9c9a0d14	2	Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
84e3196f ID	3	<http://rt2x00.serialmonkey.com>
	4
	5	This program is free software; you can redistribute it and/or modify
	6	it under the terms of the GNU General Public License as published by
	7	the Free Software Foundation; either version 2 of the License, or
	8	(at your option) any later version.
	9
	10	This program is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	GNU General Public License for more details.
	14
	15	You should have received a copy of the GNU General Public License
	16	along with this program; if not, write to the
	17	Free Software Foundation, Inc.,
	18	59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	19	*/
	20
	21	/*
	22	Module: rt2x00lib
	23	Abstract: rt2x00 generic link tuning routines.
	24	*/
	25
	26	#include <linux/kernel.h>
	27	#include <linux/module.h>
	28
	29	#include "rt2x00.h"
	30	#include "rt2x00lib.h"
	31
5352ff65 ID	32	/*
	33	* When we lack RSSI information return something less then -80 to
	34	* tell the driver to tune the device to maximum sensitivity.
	35	*/
	36	#define DEFAULT_RSSI -128
	37
1dc254ac GJ	38	/* Constants for EWMA calculations. */
	39	#define RT2X00_EWMA_FACTOR 1024
	40	#define RT2X00_EWMA_WEIGHT 8
	41
	42	static inline int rt2x00link_get_avg_rssi(struct ewma *ewma)
	43	{
	44	unsigned long avg;
	45
	46	avg = ewma_read(ewma);
	47	if (avg)
	48	return -avg;
	49
	50	return DEFAULT_RSSI;
	51	}
5352ff65	52
84e3196f ID	53	static int rt2x00link_antenna_get_link_rssi(struct rt2x00_dev *rt2x00dev)
	54	{
	55	struct link_ant *ant = &rt2x00dev->link.ant;
	56
1dc254ac GJ	57	if (rt2x00dev->link.qual.rx_success)
	58	return rt2x00link_get_avg_rssi(&ant->rssi_ant);
	59
84e3196f ID	60	return DEFAULT_RSSI;
	61	}
	62
193df183	63	static int rt2x00link_antenna_get_rssi_history(struct rt2x00_dev *rt2x00dev)
84e3196f ID	64	{
	65	struct link_ant *ant = &rt2x00dev->link.ant;
	66
193df183 LE	67	if (ant->rssi_history)
193df183 LE	68	return ant->rssi_history;
84e3196f ID	69	return DEFAULT_RSSI;
84e3196f ID	70	}
84e3196f ID	71
84e3196f ID	72	static void rt2x00link_antenna_update_rssi_history(struct rt2x00_dev *rt2x00dev,
84e3196f ID	73	int rssi)
	74	{
	75	struct link_ant *ant = &rt2x00dev->link.ant;
193df183	76	ant->rssi_history = rssi;
84e3196f	77	}
84e3196f ID	78
	79	static void rt2x00link_antenna_reset(struct rt2x00_dev *rt2x00dev)
	80	{
1dc254ac GJ	81	ewma_init(&rt2x00dev->link.ant.rssi_ant, RT2X00_EWMA_FACTOR,
1dc254ac GJ	82	RT2X00_EWMA_WEIGHT);
84e3196f ID	83	}
	84
	85	static void rt2x00lib_antenna_diversity_sample(struct rt2x00_dev *rt2x00dev)
	86	{
	87	struct link_ant *ant = &rt2x00dev->link.ant;
	88	struct antenna_setup new_ant;
193df183 LE	89	int other_antenna;
	90
	91	int sample_current = rt2x00link_antenna_get_link_rssi(rt2x00dev);
	92	int sample_other = rt2x00link_antenna_get_rssi_history(rt2x00dev);
84e3196f ID	93
	94	memcpy(&new_ant, &ant->active, sizeof(new_ant));
	95
	96	/*
	97	* We are done sampling. Now we should evaluate the results.
	98	*/
	99	ant->flags &= ~ANTENNA_MODE_SAMPLE;
	100
	101	/*
	102	* During the last period we have sampled the RSSI
49513481	103	* from both antennas. It now is time to determine
84e3196f ID	104	* which antenna demonstrated the best performance.
84e3196f ID	105	* When we are already on the antenna with the best
193df183 LE	106	* performance, just create a good starting point
193df183 LE	107	* for the history and we are done.
84e3196f	108	*/
193df183 LE	109	if (sample_current >= sample_other) {
	110	rt2x00link_antenna_update_rssi_history(rt2x00dev,
	111	sample_current);
84e3196f	112	return;
193df183 LE	113	}
	114
	115	other_antenna = (ant->active.rx == ANTENNA_A) ? ANTENNA_B : ANTENNA_A;
84e3196f ID	116
84e3196f ID	117	if (ant->flags & ANTENNA_RX_DIVERSITY)
193df183	118	new_ant.rx = other_antenna;
84e3196f ID	119
84e3196f ID	120	if (ant->flags & ANTENNA_TX_DIVERSITY)
193df183	121	new_ant.tx = other_antenna;
84e3196f	122
eb87eaac	123	rt2x00lib_config_antenna(rt2x00dev, new_ant);
84e3196f ID	124	}
	125
	126	static void rt2x00lib_antenna_diversity_eval(struct rt2x00_dev *rt2x00dev)
	127	{
	128	struct link_ant *ant = &rt2x00dev->link.ant;
	129	struct antenna_setup new_ant;
	130	int rssi_curr;
	131	int rssi_old;
	132
	133	memcpy(&new_ant, &ant->active, sizeof(new_ant));
	134
	135	/*
	136	* Get current RSSI value along with the historical value,
	137	* after that update the history with the current value.
	138	*/
	139	rssi_curr = rt2x00link_antenna_get_link_rssi(rt2x00dev);
193df183 LE	140	rssi_old = rt2x00link_antenna_get_rssi_history(rt2x00dev);
193df183 LE	141	rt2x00link_antenna_update_rssi_history(rt2x00dev, rssi_curr);
84e3196f ID	142
	143	/*
	144	* Legacy driver indicates that we should swap antenna's
	145	* when the difference in RSSI is greater that 5. This
	146	* also should be done when the RSSI was actually better
	147	* then the previous sample.
	148	* When the difference exceeds the threshold we should
	149	* sample the rssi from the other antenna to make a valid
	150	* comparison between the 2 antennas.
	151	*/
	152	if (abs(rssi_curr - rssi_old) < 5)
	153	return;
	154
	155	ant->flags \|= ANTENNA_MODE_SAMPLE;
	156
	157	if (ant->flags & ANTENNA_RX_DIVERSITY)
	158	new_ant.rx = (new_ant.rx == ANTENNA_A) ? ANTENNA_B : ANTENNA_A;
	159
	160	if (ant->flags & ANTENNA_TX_DIVERSITY)
	161	new_ant.tx = (new_ant.tx == ANTENNA_A) ? ANTENNA_B : ANTENNA_A;
	162
eb87eaac	163	rt2x00lib_config_antenna(rt2x00dev, new_ant);
84e3196f ID	164	}
84e3196f ID	165
193df183	166	static bool rt2x00lib_antenna_diversity(struct rt2x00_dev *rt2x00dev)
84e3196f ID	167	{
	168	struct link_ant *ant = &rt2x00dev->link.ant;
	169
	170	/*
	171	* Determine if software diversity is enabled for
	172	* either the TX or RX antenna (or both).
84e3196f	173	*/
84e3196f ID	174	if (!(ant->flags & ANTENNA_RX_DIVERSITY) &&
	175	!(ant->flags & ANTENNA_TX_DIVERSITY)) {
	176	ant->flags = 0;
193df183	177	return true;
84e3196f ID	178	}
	179
	180	/*
	181	* If we have only sampled the data over the last period
	182	* we should now harvest the data. Otherwise just evaluate
	183	* the data. The latter should only be performed once
	184	* every 2 seconds.
	185	*/
193df183	186	if (ant->flags & ANTENNA_MODE_SAMPLE) {
84e3196f	187	rt2x00lib_antenna_diversity_sample(rt2x00dev);
193df183 LE	188	return true;
193df183 LE	189	} else if (rt2x00dev->link.count & 1) {
84e3196f	190	rt2x00lib_antenna_diversity_eval(rt2x00dev);
193df183 LE	191	return true;
	192	}
	193
	194	return false;
84e3196f ID	195	}
	196
	197	void rt2x00link_update_stats(struct rt2x00_dev *rt2x00dev,
	198	struct sk_buff *skb,
	199	struct rxdone_entry_desc *rxdesc)
	200	{
5352ff65	201	struct link *link = &rt2x00dev->link;
84e3196f ID	202	struct link_qual *qual = &rt2x00dev->link.qual;
	203	struct link_ant *ant = &rt2x00dev->link.ant;
	204	struct ieee80211_hdr hdr = (struct ieee80211_hdr )skb->data;
84e3196f	205
a23c2208 HS	206	/*
	207	* No need to update the stats for !=STA interfaces
	208	*/
	209	if (!rt2x00dev->intf_sta_count)
	210	return;
	211
84e3196f ID	212	/*
	213	* Frame was received successfully since non-succesfull
	214	* frames would have been dropped by the hardware.
	215	*/
	216	qual->rx_success++;
	217
	218	/*
	219	* We are only interested in quality statistics from
	220	* beacons which came from the BSS which we are
	221	* associated with.
	222	*/
	223	if (!ieee80211_is_beacon(hdr->frame_control) \|\|
	224	!(rxdesc->dev_flags & RXDONE_MY_BSS))
	225	return;
	226
	227	/*
	228	* Update global RSSI
	229	*/
1dc254ac	230	ewma_add(&link->avg_rssi, -rxdesc->rssi);
84e3196f ID	231
	232	/*
	233	* Update antenna RSSI
	234	*/
1dc254ac	235	ewma_add(&ant->rssi_ant, -rxdesc->rssi);
84e3196f ID	236	}
84e3196f ID	237
84e3196f ID	238	void rt2x00link_start_tuner(struct rt2x00_dev *rt2x00dev)
84e3196f ID	239	{
5352ff65	240	struct link *link = &rt2x00dev->link;
84e3196f ID	241
	242	/*
	243	* Link tuning should only be performed when
8654b79f HS	244	* an active sta interface exists. AP interfaces
	245	* don't need link tuning and monitor mode interfaces
	246	* should never have to work with link tuners.
84e3196f	247	*/
8654b79f	248	if (!rt2x00dev->intf_sta_count)
84e3196f ID	249	return;
84e3196f ID	250
d8147f9d ID	251	/**
	252	* While scanning, link tuning is disabled. By default
	253	* the most sensitive settings will be used to make sure
25985edc	254	* that all beacons and probe responses will be received
d8147f9d ID	255	* during the scan.
	256	*/
	257	if (test_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags))
	258	return;
	259
84e3196f ID	260	rt2x00link_reset_tuner(rt2x00dev, false);
84e3196f ID	261
66f84d65 SC	262	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
	263	ieee80211_queue_delayed_work(rt2x00dev->hw,
	264	&link->work, LINK_TUNE_INTERVAL);
84e3196f ID	265	}
	266
	267	void rt2x00link_stop_tuner(struct rt2x00_dev *rt2x00dev)
	268	{
	269	cancel_delayed_work_sync(&rt2x00dev->link.work);
	270	}
	271
	272	void rt2x00link_reset_tuner(struct rt2x00_dev *rt2x00dev, bool antenna)
	273	{
5352ff65	274	struct link_qual *qual = &rt2x00dev->link.qual;
223dcc26	275	u8 vgc_level = qual->vgc_level_reg;
5352ff65	276
84e3196f ID	277	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
	278	return;
	279
	280	/*
	281	* Reset link information.
	282	* Both the currently active vgc level as well as
	283	* the link tuner counter should be reset. Resetting
	284	* the counter is important for devices where the
	285	* device should only perform link tuning during the
	286	* first minute after being enabled.
	287	*/
	288	rt2x00dev->link.count = 0;
5352ff65	289	memset(qual, 0, sizeof(*qual));
1dc254ac GJ	290	ewma_init(&rt2x00dev->link.avg_rssi, RT2X00_EWMA_FACTOR,
1dc254ac GJ	291	RT2X00_EWMA_WEIGHT);
84e3196f	292
223dcc26 ID	293	/*
	294	* Restore the VGC level as stored in the registers,
	295	* the driver can use this to determine if the register
	296	* must be updated during reset or not.
	297	*/
	298	qual->vgc_level_reg = vgc_level;
	299
84e3196f ID	300	/*
	301	* Reset the link tuner.
	302	*/
5352ff65	303	rt2x00dev->ops->lib->reset_tuner(rt2x00dev, qual);
84e3196f ID	304
	305	if (antenna)
	306	rt2x00link_antenna_reset(rt2x00dev);
	307	}
	308
a57e2e84	309	static void rt2x00link_reset_qual(struct rt2x00_dev *rt2x00dev)
64abd803 ID	310	{
	311	struct link_qual *qual = &rt2x00dev->link.qual;
	312
	313	qual->rx_success = 0;
	314	qual->rx_failed = 0;
	315	qual->tx_success = 0;
	316	qual->tx_failed = 0;
	317	}
	318
84e3196f ID	319	static void rt2x00link_tuner(struct work_struct *work)
	320	{
	321	struct rt2x00_dev *rt2x00dev =
	322	container_of(work, struct rt2x00_dev, link.work.work);
5352ff65	323	struct link *link = &rt2x00dev->link;
84e3196f ID	324	struct link_qual *qual = &rt2x00dev->link.qual;
	325
	326	/*
	327	* When the radio is shutting down we should
	328	* immediately cease all link tuning.
	329	*/
d8147f9d ID	330	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) \|\|
d8147f9d ID	331	test_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags))
84e3196f ID	332	return;
	333
	334	/*
	335	* Update statistics.
	336	*/
	337	rt2x00dev->ops->lib->link_stats(rt2x00dev, qual);
	338	rt2x00dev->low_level_stats.dot11FCSErrorCount += qual->rx_failed;
	339
5352ff65 ID	340	/*
	341	* Update quality RSSI for link tuning,
	342	* when we have received some frames and we managed to
	343	* collect the RSSI data we could use this. Otherwise we
	344	* must fallback to the default RSSI value.
	345	*/
1dc254ac	346	if (!qual->rx_success)
5352ff65 ID	347	qual->rssi = DEFAULT_RSSI;
5352ff65 ID	348	else
1dc254ac	349	qual->rssi = rt2x00link_get_avg_rssi(&link->avg_rssi);
5352ff65	350
84e3196f	351	/*
27df2a9c ID	352	* Check if link tuning is supported by the hardware, some hardware
	353	* do not support link tuning at all, while other devices can disable
	354	* the feature from the EEPROM.
84e3196f	355	*/
7b8a00dc	356	if (rt2x00_has_cap_link_tuning(rt2x00dev))
5352ff65	357	rt2x00dev->ops->lib->link_tuner(rt2x00dev, qual, link->count);
84e3196f	358
84e3196f ID	359	/*
	360	* Send a signal to the led to update the led signal strength.
	361	*/
66679a65	362	rt2x00leds_led_quality(rt2x00dev, qual->rssi);
84e3196f ID	363
84e3196f ID	364	/*
193df183 LE	365	* Evaluate antenna setup, make this the last step when
	366	* rt2x00lib_antenna_diversity made changes the quality
	367	* statistics will be reset.
64abd803	368	*/
193df183 LE	369	if (rt2x00lib_antenna_diversity(rt2x00dev))
193df183 LE	370	rt2x00link_reset_qual(rt2x00dev);
64abd803	371
84e3196f ID	372	/*
	373	* Increase tuner counter, and reschedule the next link tuner run.
	374	*/
5352ff65	375	link->count++;
66f84d65 SC	376
	377	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
	378	ieee80211_queue_delayed_work(rt2x00dev->hw,
	379	&link->work, LINK_TUNE_INTERVAL);
84e3196f ID	380	}
84e3196f ID	381
c965c74b ID	382	void rt2x00link_start_watchdog(struct rt2x00_dev *rt2x00dev)
	383	{
	384	struct link *link = &rt2x00dev->link;
	385
aca7305b HS	386	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
	387	rt2x00dev->ops->lib->watchdog)
	388	ieee80211_queue_delayed_work(rt2x00dev->hw,
	389	&link->watchdog_work,
	390	WATCHDOG_INTERVAL);
c965c74b ID	391	}
	392
	393	void rt2x00link_stop_watchdog(struct rt2x00_dev *rt2x00dev)
	394	{
	395	cancel_delayed_work_sync(&rt2x00dev->link.watchdog_work);
	396	}
	397
	398	static void rt2x00link_watchdog(struct work_struct *work)
	399	{
	400	struct rt2x00_dev *rt2x00dev =
	401	container_of(work, struct rt2x00_dev, link.watchdog_work.work);
	402	struct link *link = &rt2x00dev->link;
	403
	404	/*
	405	* When the radio is shutting down we should
	406	* immediately cease the watchdog monitoring.
	407	*/
	408	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
	409	return;
	410
	411	rt2x00dev->ops->lib->watchdog(rt2x00dev);
	412
	413	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
0439f536 ID	414	ieee80211_queue_delayed_work(rt2x00dev->hw,
	415	&link->watchdog_work,
	416	WATCHDOG_INTERVAL);
c965c74b ID	417	}
c965c74b ID	418
9e33a355 HS	419	void rt2x00link_start_agc(struct rt2x00_dev *rt2x00dev)
	420	{
	421	struct link *link = &rt2x00dev->link;
	422
	423	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
	424	rt2x00dev->ops->lib->gain_calibration)
	425	ieee80211_queue_delayed_work(rt2x00dev->hw,
	426	&link->agc_work,
	427	AGC_INTERVAL);
	428	}
	429
2e9c43dd JL	430	void rt2x00link_start_vcocal(struct rt2x00_dev *rt2x00dev)
	431	{
	432	struct link *link = &rt2x00dev->link;
	433
	434	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
	435	rt2x00dev->ops->lib->vco_calibration)
	436	ieee80211_queue_delayed_work(rt2x00dev->hw,
	437	&link->vco_work,
	438	VCO_INTERVAL);
	439	}
	440
9e33a355 HS	441	void rt2x00link_stop_agc(struct rt2x00_dev *rt2x00dev)
	442	{
	443	cancel_delayed_work_sync(&rt2x00dev->link.agc_work);
	444	}
	445
2e9c43dd JL	446	void rt2x00link_stop_vcocal(struct rt2x00_dev *rt2x00dev)
	447	{
	448	cancel_delayed_work_sync(&rt2x00dev->link.vco_work);
	449	}
	450
9e33a355 HS	451	static void rt2x00link_agc(struct work_struct *work)
	452	{
	453	struct rt2x00_dev *rt2x00dev =
	454	container_of(work, struct rt2x00_dev, link.agc_work.work);
	455	struct link *link = &rt2x00dev->link;
	456
	457	/*
	458	* When the radio is shutting down we should
	459	* immediately cease the watchdog monitoring.
	460	*/
	461	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
	462	return;
	463
	464	rt2x00dev->ops->lib->gain_calibration(rt2x00dev);
	465
	466	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
	467	ieee80211_queue_delayed_work(rt2x00dev->hw,
	468	&link->agc_work,
	469	AGC_INTERVAL);
	470	}
	471
2e9c43dd JL	472	static void rt2x00link_vcocal(struct work_struct *work)
	473	{
	474	struct rt2x00_dev *rt2x00dev =
	475	container_of(work, struct rt2x00_dev, link.vco_work.work);
	476	struct link *link = &rt2x00dev->link;
	477
	478	/*
	479	* When the radio is shutting down we should
	480	* immediately cease the VCO calibration.
	481	*/
	482	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
	483	return;
	484
	485	rt2x00dev->ops->lib->vco_calibration(rt2x00dev);
	486
	487	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
	488	ieee80211_queue_delayed_work(rt2x00dev->hw,
	489	&link->vco_work,
	490	VCO_INTERVAL);
	491	}
	492
84e3196f ID	493	void rt2x00link_register(struct rt2x00_dev *rt2x00dev)
84e3196f ID	494	{
9e33a355	495	INIT_DELAYED_WORK(&rt2x00dev->link.agc_work, rt2x00link_agc);
7b8a00dc	496	if (rt2x00_has_cap_vco_recalibration(rt2x00dev))
2e9c43dd	497	INIT_DELAYED_WORK(&rt2x00dev->link.vco_work, rt2x00link_vcocal);
c965c74b	498	INIT_DELAYED_WORK(&rt2x00dev->link.watchdog_work, rt2x00link_watchdog);
84e3196f ID	499	INIT_DELAYED_WORK(&rt2x00dev->link.work, rt2x00link_tuner);
84e3196f ID	500	}