[mirror_ubuntu-bionic-kernel.git] / drivers / net / wireless / ralink / 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, see <http://www.gnu.org/licenses/>.
 */

/*
	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

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

	avg = ewma_rssi_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_rssi_init(&rt2x00dev->link.ant.rssi_ant);
}

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_rssi_add(&link->avg_rssi, -rxdesc->rssi);

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

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

	/*
	 * Single monitor mode interfaces should never have
	 * work with link tuners.
	 */
	if (!rt2x00dev->intf_ap_count && !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_rssi_init(&rt2x00dev->link.avg_rssi);

	/*
	 * 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_sta(struct rt2x00_dev *rt2x00dev, struct link *link)
{
	struct link_qual *qual = &rt2x00dev->link.qual;

	/*
	 * 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);
}

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;

	/*
	 * 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;

	if (rt2x00dev->intf_sta_count)
		rt2x00link_tuner_sta(rt2x00dev, link);

	if (rt2x00dev->ops->lib->gain_calibration &&
	    (link->count % (AGC_SECONDS / LINK_TUNE_SECONDS)) == 0)
		rt2x00dev->ops->lib->gain_calibration(rt2x00dev);

	if (rt2x00dev->ops->lib->vco_calibration &&
	    rt2x00_has_cap_vco_recalibration(rt2x00dev) &&
	    (link->count % (VCO_SECONDS / LINK_TUNE_SECONDS)) == 0)
		rt2x00dev->ops->lib->vco_calibration(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_register(struct rt2x00_dev *rt2x00dev)
{
	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
a05b8c58	16	along with this program; if not, see <http://www.gnu.org/licenses/>.
84e3196f ID	17	*/
	18
	19	/*
	20	Module: rt2x00lib
	21	Abstract: rt2x00 generic link tuning routines.
	22	*/
	23
	24	#include <linux/kernel.h>
	25	#include <linux/module.h>
	26
	27	#include "rt2x00.h"
	28	#include "rt2x00lib.h"
	29
5352ff65 ID	30	/*
	31	* When we lack RSSI information return something less then -80 to
	32	* tell the driver to tune the device to maximum sensitivity.
	33	*/
	34	#define DEFAULT_RSSI -128
	35
11ab35ed	36	static inline int rt2x00link_get_avg_rssi(struct ewma_rssi *ewma)
1dc254ac GJ	37	{
	38	unsigned long avg;
	39
11ab35ed	40	avg = ewma_rssi_read(ewma);
1dc254ac GJ	41	if (avg)
	42	return -avg;
	43
	44	return DEFAULT_RSSI;
	45	}
5352ff65	46
84e3196f ID	47	static int rt2x00link_antenna_get_link_rssi(struct rt2x00_dev *rt2x00dev)
	48	{
	49	struct link_ant *ant = &rt2x00dev->link.ant;
	50
1dc254ac GJ	51	if (rt2x00dev->link.qual.rx_success)
	52	return rt2x00link_get_avg_rssi(&ant->rssi_ant);
	53
84e3196f ID	54	return DEFAULT_RSSI;
	55	}
	56
193df183	57	static int rt2x00link_antenna_get_rssi_history(struct rt2x00_dev *rt2x00dev)
84e3196f ID	58	{
	59	struct link_ant *ant = &rt2x00dev->link.ant;
	60
193df183 LE	61	if (ant->rssi_history)
193df183 LE	62	return ant->rssi_history;
84e3196f ID	63	return DEFAULT_RSSI;
84e3196f ID	64	}
84e3196f ID	65
84e3196f ID	66	static void rt2x00link_antenna_update_rssi_history(struct rt2x00_dev *rt2x00dev,
84e3196f ID	67	int rssi)
	68	{
	69	struct link_ant *ant = &rt2x00dev->link.ant;
193df183	70	ant->rssi_history = rssi;
84e3196f	71	}
84e3196f ID	72
	73	static void rt2x00link_antenna_reset(struct rt2x00_dev *rt2x00dev)
	74	{
11ab35ed	75	ewma_rssi_init(&rt2x00dev->link.ant.rssi_ant);
84e3196f ID	76	}
	77
	78	static void rt2x00lib_antenna_diversity_sample(struct rt2x00_dev *rt2x00dev)
	79	{
	80	struct link_ant *ant = &rt2x00dev->link.ant;
	81	struct antenna_setup new_ant;
193df183 LE	82	int other_antenna;
	83
	84	int sample_current = rt2x00link_antenna_get_link_rssi(rt2x00dev);
	85	int sample_other = rt2x00link_antenna_get_rssi_history(rt2x00dev);
84e3196f ID	86
	87	memcpy(&new_ant, &ant->active, sizeof(new_ant));
	88
	89	/*
	90	* We are done sampling. Now we should evaluate the results.
	91	*/
	92	ant->flags &= ~ANTENNA_MODE_SAMPLE;
	93
	94	/*
	95	* During the last period we have sampled the RSSI
49513481	96	* from both antennas. It now is time to determine
84e3196f ID	97	* which antenna demonstrated the best performance.
84e3196f ID	98	* When we are already on the antenna with the best
193df183 LE	99	* performance, just create a good starting point
193df183 LE	100	* for the history and we are done.
84e3196f	101	*/
193df183 LE	102	if (sample_current >= sample_other) {
	103	rt2x00link_antenna_update_rssi_history(rt2x00dev,
	104	sample_current);
84e3196f	105	return;
193df183 LE	106	}
	107
	108	other_antenna = (ant->active.rx == ANTENNA_A) ? ANTENNA_B : ANTENNA_A;
84e3196f ID	109
84e3196f ID	110	if (ant->flags & ANTENNA_RX_DIVERSITY)
193df183	111	new_ant.rx = other_antenna;
84e3196f ID	112
84e3196f ID	113	if (ant->flags & ANTENNA_TX_DIVERSITY)
193df183	114	new_ant.tx = other_antenna;
84e3196f	115
eb87eaac	116	rt2x00lib_config_antenna(rt2x00dev, new_ant);
84e3196f ID	117	}
	118
	119	static void rt2x00lib_antenna_diversity_eval(struct rt2x00_dev *rt2x00dev)
	120	{
	121	struct link_ant *ant = &rt2x00dev->link.ant;
	122	struct antenna_setup new_ant;
	123	int rssi_curr;
	124	int rssi_old;
	125
	126	memcpy(&new_ant, &ant->active, sizeof(new_ant));
	127
	128	/*
	129	* Get current RSSI value along with the historical value,
	130	* after that update the history with the current value.
	131	*/
	132	rssi_curr = rt2x00link_antenna_get_link_rssi(rt2x00dev);
193df183 LE	133	rssi_old = rt2x00link_antenna_get_rssi_history(rt2x00dev);
193df183 LE	134	rt2x00link_antenna_update_rssi_history(rt2x00dev, rssi_curr);
84e3196f ID	135
	136	/*
	137	* Legacy driver indicates that we should swap antenna's
	138	* when the difference in RSSI is greater that 5. This
	139	* also should be done when the RSSI was actually better
	140	* then the previous sample.
	141	* When the difference exceeds the threshold we should
	142	* sample the rssi from the other antenna to make a valid
	143	* comparison between the 2 antennas.
	144	*/
	145	if (abs(rssi_curr - rssi_old) < 5)
	146	return;
	147
	148	ant->flags \|= ANTENNA_MODE_SAMPLE;
	149
	150	if (ant->flags & ANTENNA_RX_DIVERSITY)
	151	new_ant.rx = (new_ant.rx == ANTENNA_A) ? ANTENNA_B : ANTENNA_A;
	152
	153	if (ant->flags & ANTENNA_TX_DIVERSITY)
	154	new_ant.tx = (new_ant.tx == ANTENNA_A) ? ANTENNA_B : ANTENNA_A;
	155
eb87eaac	156	rt2x00lib_config_antenna(rt2x00dev, new_ant);
84e3196f ID	157	}
84e3196f ID	158
193df183	159	static bool rt2x00lib_antenna_diversity(struct rt2x00_dev *rt2x00dev)
84e3196f ID	160	{
	161	struct link_ant *ant = &rt2x00dev->link.ant;
	162
	163	/*
	164	* Determine if software diversity is enabled for
	165	* either the TX or RX antenna (or both).
84e3196f	166	*/
84e3196f ID	167	if (!(ant->flags & ANTENNA_RX_DIVERSITY) &&
	168	!(ant->flags & ANTENNA_TX_DIVERSITY)) {
	169	ant->flags = 0;
193df183	170	return true;
84e3196f ID	171	}
	172
	173	/*
	174	* If we have only sampled the data over the last period
	175	* we should now harvest the data. Otherwise just evaluate
	176	* the data. The latter should only be performed once
	177	* every 2 seconds.
	178	*/
193df183	179	if (ant->flags & ANTENNA_MODE_SAMPLE) {
84e3196f	180	rt2x00lib_antenna_diversity_sample(rt2x00dev);
193df183 LE	181	return true;
193df183 LE	182	} else if (rt2x00dev->link.count & 1) {
84e3196f	183	rt2x00lib_antenna_diversity_eval(rt2x00dev);
193df183 LE	184	return true;
	185	}
	186
	187	return false;
84e3196f ID	188	}
	189
	190	void rt2x00link_update_stats(struct rt2x00_dev *rt2x00dev,
	191	struct sk_buff *skb,
	192	struct rxdone_entry_desc *rxdesc)
	193	{
5352ff65	194	struct link *link = &rt2x00dev->link;
84e3196f ID	195	struct link_qual *qual = &rt2x00dev->link.qual;
	196	struct link_ant *ant = &rt2x00dev->link.ant;
	197	struct ieee80211_hdr hdr = (struct ieee80211_hdr )skb->data;
84e3196f	198
a23c2208 HS	199	/*
	200	* No need to update the stats for !=STA interfaces
	201	*/
	202	if (!rt2x00dev->intf_sta_count)
	203	return;
	204
84e3196f ID	205	/*
	206	* Frame was received successfully since non-succesfull
	207	* frames would have been dropped by the hardware.
	208	*/
	209	qual->rx_success++;
	210
	211	/*
	212	* We are only interested in quality statistics from
	213	* beacons which came from the BSS which we are
	214	* associated with.
	215	*/
	216	if (!ieee80211_is_beacon(hdr->frame_control) \|\|
	217	!(rxdesc->dev_flags & RXDONE_MY_BSS))
	218	return;
	219
	220	/*
	221	* Update global RSSI
	222	*/
11ab35ed	223	ewma_rssi_add(&link->avg_rssi, -rxdesc->rssi);
84e3196f ID	224
	225	/*
	226	* Update antenna RSSI
	227	*/
11ab35ed	228	ewma_rssi_add(&ant->rssi_ant, -rxdesc->rssi);
84e3196f ID	229	}
84e3196f ID	230
84e3196f ID	231	void rt2x00link_start_tuner(struct rt2x00_dev *rt2x00dev)
84e3196f ID	232	{
5352ff65	233	struct link *link = &rt2x00dev->link;
84e3196f ID	234
84e3196f ID	235	/*
d9632470 SG	236	* Single monitor mode interfaces should never have
d9632470 SG	237	* work with link tuners.
84e3196f	238	*/
d9632470	239	if (!rt2x00dev->intf_ap_count && !rt2x00dev->intf_sta_count)
84e3196f ID	240	return;
84e3196f ID	241
d9632470	242	/*
d8147f9d ID	243	* While scanning, link tuning is disabled. By default
d8147f9d ID	244	* the most sensitive settings will be used to make sure
25985edc	245	* that all beacons and probe responses will be received
d8147f9d ID	246	* during the scan.
	247	*/
	248	if (test_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags))
	249	return;
	250
84e3196f ID	251	rt2x00link_reset_tuner(rt2x00dev, false);
84e3196f ID	252
66f84d65 SC	253	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
	254	ieee80211_queue_delayed_work(rt2x00dev->hw,
	255	&link->work, LINK_TUNE_INTERVAL);
84e3196f ID	256	}
	257
	258	void rt2x00link_stop_tuner(struct rt2x00_dev *rt2x00dev)
	259	{
	260	cancel_delayed_work_sync(&rt2x00dev->link.work);
	261	}
	262
	263	void rt2x00link_reset_tuner(struct rt2x00_dev *rt2x00dev, bool antenna)
	264	{
5352ff65	265	struct link_qual *qual = &rt2x00dev->link.qual;
223dcc26	266	u8 vgc_level = qual->vgc_level_reg;
5352ff65	267
84e3196f ID	268	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
	269	return;
	270
	271	/*
	272	* Reset link information.
	273	* Both the currently active vgc level as well as
	274	* the link tuner counter should be reset. Resetting
	275	* the counter is important for devices where the
	276	* device should only perform link tuning during the
	277	* first minute after being enabled.
	278	*/
	279	rt2x00dev->link.count = 0;
5352ff65	280	memset(qual, 0, sizeof(*qual));
11ab35ed	281	ewma_rssi_init(&rt2x00dev->link.avg_rssi);
84e3196f	282
223dcc26 ID	283	/*
	284	* Restore the VGC level as stored in the registers,
	285	* the driver can use this to determine if the register
	286	* must be updated during reset or not.
	287	*/
	288	qual->vgc_level_reg = vgc_level;
	289
84e3196f ID	290	/*
	291	* Reset the link tuner.
	292	*/
5352ff65	293	rt2x00dev->ops->lib->reset_tuner(rt2x00dev, qual);
84e3196f ID	294
	295	if (antenna)
	296	rt2x00link_antenna_reset(rt2x00dev);
	297	}
	298
a57e2e84	299	static void rt2x00link_reset_qual(struct rt2x00_dev *rt2x00dev)
64abd803 ID	300	{
	301	struct link_qual *qual = &rt2x00dev->link.qual;
	302
	303	qual->rx_success = 0;
	304	qual->rx_failed = 0;
	305	qual->tx_success = 0;
	306	qual->tx_failed = 0;
	307	}
	308
d9632470	309	static void rt2x00link_tuner_sta(struct rt2x00_dev rt2x00dev, struct link link)
84e3196f	310	{
84e3196f ID	311	struct link_qual *qual = &rt2x00dev->link.qual;
84e3196f ID	312
84e3196f ID	313	/*
	314	* Update statistics.
	315	*/
	316	rt2x00dev->ops->lib->link_stats(rt2x00dev, qual);
	317	rt2x00dev->low_level_stats.dot11FCSErrorCount += qual->rx_failed;
	318
5352ff65 ID	319	/*
	320	* Update quality RSSI for link tuning,
	321	* when we have received some frames and we managed to
	322	* collect the RSSI data we could use this. Otherwise we
	323	* must fallback to the default RSSI value.
	324	*/
1dc254ac	325	if (!qual->rx_success)
5352ff65 ID	326	qual->rssi = DEFAULT_RSSI;
5352ff65 ID	327	else
1dc254ac	328	qual->rssi = rt2x00link_get_avg_rssi(&link->avg_rssi);
5352ff65	329
84e3196f	330	/*
27df2a9c ID	331	* Check if link tuning is supported by the hardware, some hardware
	332	* do not support link tuning at all, while other devices can disable
	333	* the feature from the EEPROM.
84e3196f	334	*/
7b8a00dc	335	if (rt2x00_has_cap_link_tuning(rt2x00dev))
5352ff65	336	rt2x00dev->ops->lib->link_tuner(rt2x00dev, qual, link->count);
84e3196f	337
84e3196f ID	338	/*
	339	* Send a signal to the led to update the led signal strength.
	340	*/
66679a65	341	rt2x00leds_led_quality(rt2x00dev, qual->rssi);
84e3196f ID	342
84e3196f ID	343	/*
193df183 LE	344	* Evaluate antenna setup, make this the last step when
	345	* rt2x00lib_antenna_diversity made changes the quality
	346	* statistics will be reset.
64abd803	347	*/
193df183 LE	348	if (rt2x00lib_antenna_diversity(rt2x00dev))
193df183 LE	349	rt2x00link_reset_qual(rt2x00dev);
d9632470 SG	350	}
	351
	352	static void rt2x00link_tuner(struct work_struct *work)
	353	{
	354	struct rt2x00_dev *rt2x00dev =
	355	container_of(work, struct rt2x00_dev, link.work.work);
	356	struct link *link = &rt2x00dev->link;
	357
	358	/*
	359	* When the radio is shutting down we should
	360	* immediately cease all link tuning.
	361	*/
	362	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) \|\|
	363	test_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags))
	364	return;
	365
	366	if (rt2x00dev->intf_sta_count)
	367	rt2x00link_tuner_sta(rt2x00dev, link);
	368
	369	if (rt2x00dev->ops->lib->gain_calibration &&
	370	(link->count % (AGC_SECONDS / LINK_TUNE_SECONDS)) == 0)
	371	rt2x00dev->ops->lib->gain_calibration(rt2x00dev);
	372
	373	if (rt2x00dev->ops->lib->vco_calibration &&
	374	rt2x00_has_cap_vco_recalibration(rt2x00dev) &&
	375	(link->count % (VCO_SECONDS / LINK_TUNE_SECONDS)) == 0)
	376	rt2x00dev->ops->lib->vco_calibration(rt2x00dev);
64abd803	377
84e3196f ID	378	/*
	379	* Increase tuner counter, and reschedule the next link tuner run.
	380	*/
5352ff65	381	link->count++;
66f84d65 SC	382
	383	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
	384	ieee80211_queue_delayed_work(rt2x00dev->hw,
	385	&link->work, LINK_TUNE_INTERVAL);
84e3196f ID	386	}
84e3196f ID	387
c965c74b ID	388	void rt2x00link_start_watchdog(struct rt2x00_dev *rt2x00dev)
	389	{
	390	struct link *link = &rt2x00dev->link;
	391
aca7305b HS	392	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) &&
	393	rt2x00dev->ops->lib->watchdog)
	394	ieee80211_queue_delayed_work(rt2x00dev->hw,
	395	&link->watchdog_work,
	396	WATCHDOG_INTERVAL);
c965c74b ID	397	}
	398
	399	void rt2x00link_stop_watchdog(struct rt2x00_dev *rt2x00dev)
	400	{
	401	cancel_delayed_work_sync(&rt2x00dev->link.watchdog_work);
	402	}
	403
	404	static void rt2x00link_watchdog(struct work_struct *work)
	405	{
	406	struct rt2x00_dev *rt2x00dev =
	407	container_of(work, struct rt2x00_dev, link.watchdog_work.work);
	408	struct link *link = &rt2x00dev->link;
	409
	410	/*
	411	* When the radio is shutting down we should
	412	* immediately cease the watchdog monitoring.
	413	*/
	414	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
	415	return;
	416
	417	rt2x00dev->ops->lib->watchdog(rt2x00dev);
	418
	419	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
0439f536 ID	420	ieee80211_queue_delayed_work(rt2x00dev->hw,
	421	&link->watchdog_work,
	422	WATCHDOG_INTERVAL);
c965c74b ID	423	}
c965c74b ID	424
84e3196f ID	425	void rt2x00link_register(struct rt2x00_dev *rt2x00dev)
84e3196f ID	426	{
c965c74b	427	INIT_DELAYED_WORK(&rt2x00dev->link.watchdog_work, rt2x00link_watchdog);
84e3196f ID	428	INIT_DELAYED_WORK(&rt2x00dev->link.work, rt2x00link_tuner);
84e3196f ID	429	}