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>
diff --git a/drivers/net/wireless/rt2x00/rt2x00link.c b/drivers/net/wireless/rt2x00/rt2x00link.c
new file mode 100644
index 0000000..0462d5a
--- /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);
+}