diff options
author | Ivo van Doorn <ivdoorn@gmail.com> | 2008-12-20 10:53:29 +0100 |
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committer | John W. Linville <linville@tuxdriver.com> | 2009-01-29 21:58:34 +0100 |
commit | 84e3196ff867c623056eea02c11a45e046490d89 (patch) | |
tree | a2f5c1d69a63b22f202713a501762a777e04d19a /drivers/net/wireless/rt2x00/rt2x00link.c | |
parent | rt2x00: Implement Powersaving (diff) | |
download | linux-84e3196ff867c623056eea02c11a45e046490d89.tar.xz linux-84e3196ff867c623056eea02c11a45e046490d89.zip |
rt2x00: Move link tuning into seperate file
Move link and antenna tuning into a seperate file named rt2x00link.c,
this makes the interface to the link tuner a lot cleaner.
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'drivers/net/wireless/rt2x00/rt2x00link.c')
-rw-r--r-- | drivers/net/wireless/rt2x00/rt2x00link.c | 402 |
1 files changed, 402 insertions, 0 deletions
diff --git a/drivers/net/wireless/rt2x00/rt2x00link.c b/drivers/net/wireless/rt2x00/rt2x00link.c new file mode 100644 index 000000000000..0462d5ab6e97 --- /dev/null +++ b/drivers/net/wireless/rt2x00/rt2x00link.c @@ -0,0 +1,402 @@ +/* + Copyright (C) 2004 - 2008 rt2x00 SourceForge Project + <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" + +static int rt2x00link_antenna_get_link_rssi(struct rt2x00_dev *rt2x00dev) +{ + struct link_ant *ant = &rt2x00dev->link.ant; + + if (ant->rssi_ant && rt2x00dev->link.qual.rx_success) + return ant->rssi_ant; + return DEFAULT_RSSI; +} + +static int rt2x00link_antenna_get_rssi_history(struct rt2x00_dev *rt2x00dev, + enum antenna antenna) +{ + struct link_ant *ant = &rt2x00dev->link.ant; + + if (ant->rssi_history[antenna - ANTENNA_A]) + return ant->rssi_history[antenna - ANTENNA_A]; + return DEFAULT_RSSI; +} +/* Small wrapper for rt2x00link_antenna_get_rssi_history() */ +#define rt2x00link_antenna_get_rssi_rx_history(__dev) \ + rt2x00link_antenna_get_rssi_history((__dev), \ + (__dev)->link.ant.active.rx) +#define rt2x00link_antenna_get_rssi_tx_history(__dev) \ + rt2x00link_antenna_get_rssi_history((__dev), \ + (__dev)->link.ant.active.tx) + +static void rt2x00link_antenna_update_rssi_history(struct rt2x00_dev *rt2x00dev, + enum antenna antenna, + int rssi) +{ + struct link_ant *ant = &rt2x00dev->link.ant; + ant->rssi_history[ant->active.rx - ANTENNA_A] = rssi; +} +/* Small wrapper for rt2x00link_antenna_get_rssi_history() */ +#define rt2x00link_antenna_update_rssi_rx_history(__dev, __rssi) \ + rt2x00link_antenna_update_rssi_history((__dev), \ + (__dev)->link.ant.active.rx, \ + (__rssi)) +#define rt2x00link_antenna_update_rssi_tx_history(__dev, __rssi) \ + rt2x00link_antenna_update_rssi_history((__dev), \ + (__dev)->link.ant.active.tx, \ + (__rssi)) + +static void rt2x00link_antenna_reset(struct rt2x00_dev *rt2x00dev) +{ + rt2x00dev->link.ant.rssi_ant = 0; +} + +static void rt2x00lib_antenna_diversity_sample(struct rt2x00_dev *rt2x00dev) +{ + struct link_ant *ant = &rt2x00dev->link.ant; + struct antenna_setup new_ant; + int sample_a = rt2x00link_antenna_get_rssi_history(rt2x00dev, ANTENNA_A); + int sample_b = rt2x00link_antenna_get_rssi_history(rt2x00dev, ANTENNA_B); + + 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 antenna's. It now is time to determine + * which antenna demonstrated the best performance. + * When we are already on the antenna with the best + * performance, then there really is nothing for us + * left to do. + */ + if (sample_a == sample_b) + return; + + if (ant->flags & ANTENNA_RX_DIVERSITY) + new_ant.rx = (sample_a > sample_b) ? ANTENNA_A : ANTENNA_B; + + if (ant->flags & ANTENNA_TX_DIVERSITY) + new_ant.tx = (sample_a > sample_b) ? ANTENNA_A : ANTENNA_B; + + 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_rx_history(rt2x00dev); + rt2x00link_antenna_update_rssi_rx_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 void 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). + * Always perform this check since within the link + * tuner interval the configuration might have changed. + */ + ant->flags &= ~ANTENNA_RX_DIVERSITY; + ant->flags &= ~ANTENNA_TX_DIVERSITY; + + if (rt2x00dev->default_ant.rx == ANTENNA_SW_DIVERSITY) + ant->flags |= ANTENNA_RX_DIVERSITY; + if (rt2x00dev->default_ant.tx == ANTENNA_SW_DIVERSITY) + ant->flags |= ANTENNA_TX_DIVERSITY; + + if (!(ant->flags & ANTENNA_RX_DIVERSITY) && + !(ant->flags & ANTENNA_TX_DIVERSITY)) { + ant->flags = 0; + return; + } + + /* + * 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); + else if (rt2x00dev->link.count & 1) + rt2x00lib_antenna_diversity_eval(rt2x00dev); +} + +void rt2x00link_update_stats(struct rt2x00_dev *rt2x00dev, + struct sk_buff *skb, + struct rxdone_entry_desc *rxdesc) +{ + struct link_qual *qual = &rt2x00dev->link.qual; + struct link_ant *ant = &rt2x00dev->link.ant; + struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; + int avg_rssi = rxdesc->rssi; + int ant_rssi = rxdesc->rssi; + + /* + * 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 + */ + if (qual->avg_rssi) + avg_rssi = MOVING_AVERAGE(qual->avg_rssi, rxdesc->rssi, 8); + qual->avg_rssi = avg_rssi; + + /* + * Update antenna RSSI + */ + if (ant->rssi_ant) + ant_rssi = MOVING_AVERAGE(ant->rssi_ant, rxdesc->rssi, 8); + ant->rssi_ant = ant_rssi; +} + +static void rt2x00link_precalculate_signal(struct rt2x00_dev *rt2x00dev) +{ + struct link_qual *qual = &rt2x00dev->link.qual; + + if (qual->rx_failed || qual->rx_success) + qual->rx_percentage = + (qual->rx_success * 100) / + (qual->rx_failed + qual->rx_success); + else + qual->rx_percentage = 50; + + if (qual->tx_failed || qual->tx_success) + qual->tx_percentage = + (qual->tx_success * 100) / + (qual->tx_failed + qual->tx_success); + else + qual->tx_percentage = 50; + + qual->rx_success = 0; + qual->rx_failed = 0; + qual->tx_success = 0; + qual->tx_failed = 0; +} + +int rt2x00link_calculate_signal(struct rt2x00_dev *rt2x00dev, int rssi) +{ + struct link_qual *qual = &rt2x00dev->link.qual; + int rssi_percentage = 0; + int signal; + + /* + * We need a positive value for the RSSI. + */ + if (rssi < 0) + rssi += rt2x00dev->rssi_offset; + + /* + * Calculate the different percentages, + * which will be used for the signal. + */ + rssi_percentage = (rssi * 100) / rt2x00dev->rssi_offset; + + /* + * Add the individual percentages and use the WEIGHT + * defines to calculate the current link signal. + */ + signal = ((WEIGHT_RSSI * rssi_percentage) + + (WEIGHT_TX * qual->tx_percentage) + + (WEIGHT_RX * qual->rx_percentage)) / 100; + + return max_t(int, signal, 100); +} + +void rt2x00link_start_tuner(struct rt2x00_dev *rt2x00dev) +{ + struct link_qual *qual = &rt2x00dev->link.qual; + + /* + * Link tuning should only be performed when + * an active sta or master interface exists. + * Single monitor mode interfaces should never have + * work with link tuners. + */ + if (!rt2x00dev->intf_ap_count && !rt2x00dev->intf_sta_count) + return; + + /* + * Clear all (possibly) pre-existing quality statistics. + */ + memset(qual, 0, sizeof(*qual)); + + /* + * The RX and TX percentage should start at 50% + * this will assure we will get at least get some + * decent value when the link tuner starts. + * The value will be dropped and overwritten with + * the correct (measured) value anyway during the + * first run of the link tuner. + */ + qual->rx_percentage = 50; + qual->tx_percentage = 50; + + rt2x00link_reset_tuner(rt2x00dev, false); + + queue_delayed_work(rt2x00dev->hw->workqueue, + &rt2x00dev->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) +{ + 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; + rt2x00dev->link.vgc_level = 0; + + /* + * Reset the link tuner. + */ + rt2x00dev->ops->lib->reset_tuner(rt2x00dev); + + if (antenna) + rt2x00link_antenna_reset(rt2x00dev); +} + +static void rt2x00link_tuner(struct work_struct *work) +{ + struct rt2x00_dev *rt2x00dev = + container_of(work, struct rt2x00_dev, link.work.work); + 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)) + return; + + /* + * Update statistics. + */ + rt2x00dev->ops->lib->link_stats(rt2x00dev, qual); + rt2x00dev->low_level_stats.dot11FCSErrorCount += qual->rx_failed; + + /* + * Only perform the link tuning when Link tuning + * has been enabled (This could have been disabled from the EEPROM). + */ + if (!test_bit(CONFIG_DISABLE_LINK_TUNING, &rt2x00dev->flags)) + rt2x00dev->ops->lib->link_tuner(rt2x00dev); + + /* + * Precalculate a portion of the link signal which is + * in based on the tx/rx success/failure counters. + */ + rt2x00link_precalculate_signal(rt2x00dev); + + /* + * Send a signal to the led to update the led signal strength. + */ + rt2x00leds_led_quality(rt2x00dev, qual->avg_rssi); + + /* + * Evaluate antenna setup, make this the last step since this could + * possibly reset some statistics. + */ + rt2x00lib_antenna_diversity(rt2x00dev); + + /* + * Increase tuner counter, and reschedule the next link tuner run. + */ + rt2x00dev->link.count++; + queue_delayed_work(rt2x00dev->hw->workqueue, + &rt2x00dev->link.work, LINK_TUNE_INTERVAL); +} + +void rt2x00link_register(struct rt2x00_dev *rt2x00dev) +{ + INIT_DELAYED_WORK(&rt2x00dev->link.work, rt2x00link_tuner); +} |