1 files changed, 744 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath5k/ani.c b/drivers/net/wireless/ath/ath5k/ani.c
new file mode 100644
index 000000000000..584a32859bdb
--- /dev/null
+++ b/drivers/net/wireless/ath/ath5k/ani.c
@@ -0,0 +1,744 @@
+/*
+ * Copyright (C) 2010 Bruno Randolf <br1@einfach.org>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "ath5k.h"
+#include "base.h"
+#include "reg.h"
+#include "debug.h"
+#include "ani.h"
+
+/**
+ * DOC: Basic ANI Operation
+ *
+ * Adaptive Noise Immunity (ANI) controls five noise immunity parameters
+ * depending on the amount of interference in the environment, increasing
+ * or reducing sensitivity as necessary.
+ *
+ * The parameters are:
+ *   - "noise immunity"
+ *   - "spur immunity"
+ *   - "firstep level"
+ *   - "OFDM weak signal detection"
+ *   - "CCK weak signal detection"
+ *
+ * Basically we look at the amount of ODFM and CCK timing errors we get and then
+ * raise or lower immunity accordingly by setting one or more of these
+ * parameters.
+ * Newer chipsets have PHY error counters in hardware which will generate a MIB
+ * interrupt when they overflow. Older hardware has too enable PHY error frames
+ * by setting a RX flag and then count every single PHY error. When a specified
+ * threshold of errors has been reached we will raise immunity.
+ * Also we regularly check the amount of errors and lower or raise immunity as
+ * necessary.
+ */
+
+
+/*** ANI parameter control ***/
+
+/**
+ * ath5k_ani_set_noise_immunity_level() - Set noise immunity level
+ *
+ * @level: level between 0 and @ATH5K_ANI_MAX_NOISE_IMM_LVL
+ */
+void
+ath5k_ani_set_noise_immunity_level(struct ath5k_hw *ah, int level)
+{
+        /* TODO:
+         * ANI documents suggest the following five levels to use, but the HAL
+         * and ath9k use only use the last two levels, making this
+         * essentially an on/off option. There *may* be a reason for this (???),
+         * so i stick with the HAL version for now...
+         */
+#if 0
+        const s8 hi[] = { -18, -18, -16, -14, -12 };
+        const s8 lo[] = { -52, -56, -60, -64, -70 };
+        const s8 sz[] = { -34, -41, -48, -55, -62 };
+        const s8 fr[] = { -70, -72, -75, -78, -80 };
+#else
+        const s8 sz[] = { -55, -62 };
+        const s8 lo[] = { -64, -70 };
+        const s8 hi[] = { -14, -12 };
+        const s8 fr[] = { -78, -80 };
+#endif
+        if (level < 0 || level > ARRAY_SIZE(sz)) {
+                ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI,
+                        "level out of range %d", level);
+                return;
+        }
+
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_DESIRED_SIZE,
+                                AR5K_PHY_DESIRED_SIZE_TOT, sz[level]);
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_AGCCOARSE,
+                                AR5K_PHY_AGCCOARSE_LO, lo[level]);
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_AGCCOARSE,
+                                AR5K_PHY_AGCCOARSE_HI, hi[level]);
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_SIG,
+                                AR5K_PHY_SIG_FIRPWR, fr[level]);
+
+        ah->ah_sc->ani_state.noise_imm_level = level;
+        ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI, "new level %d", level);
+}
+
+
+/**
+ * ath5k_ani_set_spur_immunity_level() - Set spur immunity level
+ *
+ * @level: level between 0 and @max_spur_level (the maximum level is dependent
+ *      on the chip revision).
+ */
+void
+ath5k_ani_set_spur_immunity_level(struct ath5k_hw *ah, int level)
+{
+        const int val[] = { 2, 4, 6, 8, 10, 12, 14, 16 };
+
+        if (level < 0 || level > ARRAY_SIZE(val) ||
+            level > ah->ah_sc->ani_state.max_spur_level) {
+                ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI,
+                        "level out of range %d", level);
+                return;
+        }
+
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_OFDM_SELFCORR,
+                AR5K_PHY_OFDM_SELFCORR_CYPWR_THR1, val[level]);
+
+        ah->ah_sc->ani_state.spur_level = level;
+        ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI, "new level %d", level);
+}
+
+
+/**
+ * ath5k_ani_set_firstep_level() - Set "firstep" level
+ *
+ * @level: level between 0 and @ATH5K_ANI_MAX_FIRSTEP_LVL
+ */
+void
+ath5k_ani_set_firstep_level(struct ath5k_hw *ah, int level)
+{
+        const int val[] = { 0, 4, 8 };
+
+        if (level < 0 || level > ARRAY_SIZE(val)) {
+                ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI,
+                        "level out of range %d", level);
+                return;
+        }
+
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_SIG,
+                                AR5K_PHY_SIG_FIRSTEP, val[level]);
+
+        ah->ah_sc->ani_state.firstep_level = level;
+        ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI, "new level %d", level);
+}
+
+
+/**
+ * ath5k_ani_set_ofdm_weak_signal_detection() - Control OFDM weak signal
+ *                                              detection
+ *
+ * @on: turn on or off
+ */
+void
+ath5k_ani_set_ofdm_weak_signal_detection(struct ath5k_hw *ah, bool on)
+{
+        const int m1l[] = { 127, 50 };
+        const int m2l[] = { 127, 40 };
+        const int m1[] = { 127, 0x4d };
+        const int m2[] = { 127, 0x40 };
+        const int m2cnt[] = { 31, 16 };
+        const int m2lcnt[] = { 63, 48 };
+
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_WEAK_OFDM_LOW_THR,
+                                AR5K_PHY_WEAK_OFDM_LOW_THR_M1, m1l[on]);
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_WEAK_OFDM_LOW_THR,
+                                AR5K_PHY_WEAK_OFDM_LOW_THR_M2, m2l[on]);
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_WEAK_OFDM_HIGH_THR,
+                                AR5K_PHY_WEAK_OFDM_HIGH_THR_M1, m1[on]);
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_WEAK_OFDM_HIGH_THR,
+                                AR5K_PHY_WEAK_OFDM_HIGH_THR_M2, m2[on]);
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_WEAK_OFDM_HIGH_THR,
+                        AR5K_PHY_WEAK_OFDM_HIGH_THR_M2_COUNT, m2cnt[on]);
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_WEAK_OFDM_LOW_THR,
+                        AR5K_PHY_WEAK_OFDM_LOW_THR_M2_COUNT, m2lcnt[on]);
+
+        if (on)
+                AR5K_REG_ENABLE_BITS(ah, AR5K_PHY_WEAK_OFDM_LOW_THR,
+                                AR5K_PHY_WEAK_OFDM_LOW_THR_SELFCOR_EN);
+        else
+                AR5K_REG_DISABLE_BITS(ah, AR5K_PHY_WEAK_OFDM_LOW_THR,
+                                AR5K_PHY_WEAK_OFDM_LOW_THR_SELFCOR_EN);
+
+        ah->ah_sc->ani_state.ofdm_weak_sig = on;
+        ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI, "turned %s",
+                          on ? "on" : "off");
+}
+
+
+/**
+ * ath5k_ani_set_cck_weak_signal_detection() - control CCK weak signal detection
+ *
+ * @on: turn on or off
+ */
+void
+ath5k_ani_set_cck_weak_signal_detection(struct ath5k_hw *ah, bool on)
+{
+        const int val[] = { 8, 6 };
+        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_CCK_CROSSCORR,
+                                AR5K_PHY_CCK_CROSSCORR_WEAK_SIG_THR, val[on]);
+        ah->ah_sc->ani_state.cck_weak_sig = on;
+        ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI, "turned %s",
+                          on ? "on" : "off");
+}
+
+
+/*** ANI algorithm ***/
+
+/**
+ * ath5k_ani_raise_immunity() - Increase noise immunity
+ *
+ * @ofdm_trigger: If this is true we are called because of too many OFDM errors,
+ *      the algorithm will tune more parameters then.
+ *
+ * Try to raise noise immunity (=decrease sensitivity) in several steps
+ * depending on the average RSSI of the beacons we received.
+ */
+static void
+ath5k_ani_raise_immunity(struct ath5k_hw *ah, struct ath5k_ani_state *as,
+                         bool ofdm_trigger)
+{
+        int rssi = ah->ah_beacon_rssi_avg.avg;
+
+        ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI, "raise immunity (%s)",
+                ofdm_trigger ? "ODFM" : "CCK");
+
+        /* first: raise noise immunity */
+        if (as->noise_imm_level < ATH5K_ANI_MAX_NOISE_IMM_LVL) {
+                ath5k_ani_set_noise_immunity_level(ah, as->noise_imm_level + 1);
+                return;
+        }
+
+        /* only OFDM: raise spur immunity level */
+        if (ofdm_trigger &&
+            as->spur_level < ah->ah_sc->ani_state.max_spur_level) {
+                ath5k_ani_set_spur_immunity_level(ah, as->spur_level + 1);
+                return;
+        }
+
+        /* AP mode */
+        if (ah->ah_sc->opmode == NL80211_IFTYPE_AP) {
+                if (as->firstep_level < ATH5K_ANI_MAX_FIRSTEP_LVL)
+                        ath5k_ani_set_firstep_level(ah, as->firstep_level + 1);
+                return;
+        }
+
+        /* STA and IBSS mode */
+
+        /* TODO: for IBSS mode it would be better to keep a beacon RSSI average
+         * per each neighbour node and use the minimum of these, to make sure we
+         * don't shut out a remote node by raising immunity too high. */
+
+        if (rssi > ATH5K_ANI_RSSI_THR_HIGH) {
+                ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI,
+                                  "beacon RSSI high");
+                /* only OFDM: beacon RSSI is high, we can disable ODFM weak
+                 * signal detection */
+                if (ofdm_trigger && as->ofdm_weak_sig == true) {
+                        ath5k_ani_set_ofdm_weak_signal_detection(ah, false);
+                        ath5k_ani_set_spur_immunity_level(ah, 0);
+                        return;
+                }
+                /* as a last resort or CCK: raise firstep level */
+                if (as->firstep_level < ATH5K_ANI_MAX_FIRSTEP_LVL) {
+                        ath5k_ani_set_firstep_level(ah, as->firstep_level + 1);
+                        return;
+                }
+        } else if (rssi > ATH5K_ANI_RSSI_THR_LOW) {
+                /* beacon RSSI in mid range, we need OFDM weak signal detect,
+                 * but can raise firstep level */
+                ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI,
+                                  "beacon RSSI mid");
+                if (ofdm_trigger && as->ofdm_weak_sig == false)
+                        ath5k_ani_set_ofdm_weak_signal_detection(ah, true);
+                if (as->firstep_level < ATH5K_ANI_MAX_FIRSTEP_LVL)
+                        ath5k_ani_set_firstep_level(ah, as->firstep_level + 1);
+                return;
+        } else if (ah->ah_current_channel->band == IEEE80211_BAND_2GHZ) {
+                /* beacon RSSI is low. in B/G mode turn of OFDM weak signal
+                 * detect and zero firstep level to maximize CCK sensitivity */
+                ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI,
+                                  "beacon RSSI low, 2GHz");
+                if (ofdm_trigger && as->ofdm_weak_sig == true)
+                        ath5k_ani_set_ofdm_weak_signal_detection(ah, false);
+                if (as->firstep_level > 0)
+                        ath5k_ani_set_firstep_level(ah, 0);
+                return;
+        }
+
+        /* TODO: why not?:
+        if (as->cck_weak_sig == true) {
+                ath5k_ani_set_cck_weak_signal_detection(ah, false);
+        }
+        */
+}
+
+
+/**
+ * ath5k_ani_lower_immunity() - Decrease noise immunity
+ *
+ * Try to lower noise immunity (=increase sensitivity) in several steps
+ * depending on the average RSSI of the beacons we received.
+ */
+static void
+ath5k_ani_lower_immunity(struct ath5k_hw *ah, struct ath5k_ani_state *as)
+{
+        int rssi = ah->ah_beacon_rssi_avg.avg;
+
+        ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI, "lower immunity");
+
+        if (ah->ah_sc->opmode == NL80211_IFTYPE_AP) {
+                /* AP mode */
+                if (as->firstep_level > 0) {
+                        ath5k_ani_set_firstep_level(ah, as->firstep_level - 1);
+                        return;
+                }
+        } else {
+                /* STA and IBSS mode (see TODO above) */
+                if (rssi > ATH5K_ANI_RSSI_THR_HIGH) {
+                        /* beacon signal is high, leave OFDM weak signal
+                         * detection off or it may oscillate
+                         * TODO: who said it's off??? */
+                } else if (rssi > ATH5K_ANI_RSSI_THR_LOW) {
+                        /* beacon RSSI is mid-range: turn on ODFM weak signal
+                         * detection and next, lower firstep level */
+                        if (as->ofdm_weak_sig == false) {
+                                ath5k_ani_set_ofdm_weak_signal_detection(ah,
+                                                                         true);
+                                return;
+                        }
+                        if (as->firstep_level > 0) {
+                                ath5k_ani_set_firstep_level(ah,
+                                                        as->firstep_level - 1);
+                                return;
+                        }
+                } else {
+                        /* beacon signal is low: only reduce firstep level */
+                        if (as->firstep_level > 0) {
+                                ath5k_ani_set_firstep_level(ah,
+                                                        as->firstep_level - 1);
+                                return;
+                        }
+                }
+        }
+
+        /* all modes */
+        if (as->spur_level > 0) {
+                ath5k_ani_set_spur_immunity_level(ah, as->spur_level - 1);
+                return;
+        }
+
+        /* finally, reduce noise immunity */
+        if (as->noise_imm_level > 0) {
+                ath5k_ani_set_noise_immunity_level(ah, as->noise_imm_level - 1);
+                return;
+        }
+}
+
+
+/**
+ * ath5k_hw_ani_get_listen_time() - Calculate time spent listening
+ *
+ * Return an approximation of the time spent "listening" in milliseconds (ms)
+ * since the last call of this function by deducting the cycles spent
+ * transmitting and receiving from the total cycle count.
+ * Save profile count values for debugging/statistics and because we might want
+ * to use them later.
+ *
+ * We assume no one else clears these registers!
+ */
+static int
+ath5k_hw_ani_get_listen_time(struct ath5k_hw *ah, struct ath5k_ani_state *as)
+{
+        int listen;
+
+        /* freeze */
+        ath5k_hw_reg_write(ah, AR5K_MIBC_FMC, AR5K_MIBC);
+        /* read */
+        as->pfc_cycles = ath5k_hw_reg_read(ah, AR5K_PROFCNT_CYCLE);
+        as->pfc_busy = ath5k_hw_reg_read(ah, AR5K_PROFCNT_RXCLR);
+        as->pfc_tx = ath5k_hw_reg_read(ah, AR5K_PROFCNT_TX);
+        as->pfc_rx = ath5k_hw_reg_read(ah, AR5K_PROFCNT_RX);
+        /* clear */
+        ath5k_hw_reg_write(ah, 0, AR5K_PROFCNT_TX);
+        ath5k_hw_reg_write(ah, 0, AR5K_PROFCNT_RX);
+        ath5k_hw_reg_write(ah, 0, AR5K_PROFCNT_RXCLR);
+        ath5k_hw_reg_write(ah, 0, AR5K_PROFCNT_CYCLE);
+        /* un-freeze */
+        ath5k_hw_reg_write(ah, 0, AR5K_MIBC);
+
+        /* TODO: where does 44000 come from? (11g clock rate?) */
+        listen = (as->pfc_cycles - as->pfc_rx - as->pfc_tx) / 44000;
+
+        if (as->pfc_cycles == 0 || listen < 0)
+                return 0;
+        return listen;
+}
+
+
+/**
+ * ath5k_ani_save_and_clear_phy_errors() - Clear and save PHY error counters
+ *
+ * Clear the PHY error counters as soon as possible, since this might be called
+ * from a MIB interrupt and we want to make sure we don't get interrupted again.
+ * Add the count of CCK and OFDM errors to our internal state, so it can be used
+ * by the algorithm later.
+ *
+ * Will be called from interrupt and tasklet context.
+ * Returns 0 if both counters are zero.
+ */
+static int
+ath5k_ani_save_and_clear_phy_errors(struct ath5k_hw *ah,
+                                    struct ath5k_ani_state *as)
+{
+        unsigned int ofdm_err, cck_err;
+
+        if (!ah->ah_capabilities.cap_has_phyerr_counters)
+                return 0;
+
+        ofdm_err = ath5k_hw_reg_read(ah, AR5K_PHYERR_CNT1);
+        cck_err = ath5k_hw_reg_read(ah, AR5K_PHYERR_CNT2);
+
+        /* reset counters first, we might be in a hurry (interrupt) */
+        ath5k_hw_reg_write(ah, ATH5K_PHYERR_CNT_MAX - ATH5K_ANI_OFDM_TRIG_HIGH,
+                           AR5K_PHYERR_CNT1);
+        ath5k_hw_reg_write(ah, ATH5K_PHYERR_CNT_MAX - ATH5K_ANI_CCK_TRIG_HIGH,
+                           AR5K_PHYERR_CNT2);
+
+        ofdm_err = ATH5K_ANI_OFDM_TRIG_HIGH - (ATH5K_PHYERR_CNT_MAX - ofdm_err);
+        cck_err = ATH5K_ANI_CCK_TRIG_HIGH - (ATH5K_PHYERR_CNT_MAX - cck_err);
+
+        /* sometimes both can be zero, especially when there is a superfluous
+         * second interrupt. detect that here and return an error. */
+        if (ofdm_err <= 0 && cck_err <= 0)
+                return 0;
+
+        /* avoid negative values should one of the registers overflow */
+        if (ofdm_err > 0) {
+                as->ofdm_errors += ofdm_err;
+                as->sum_ofdm_errors += ofdm_err;
+        }
+        if (cck_err > 0) {
+                as->cck_errors += cck_err;
+                as->sum_cck_errors += cck_err;
+        }
+        return 1;
+}
+
+
+/**
+ * ath5k_ani_period_restart() - Restart ANI period
+ *
+ * Just reset counters, so they are clear for the next "ani period".
+ */
+static void
+ath5k_ani_period_restart(struct ath5k_hw *ah, struct ath5k_ani_state *as)
+{
+        /* keep last values for debugging */
+        as->last_ofdm_errors = as->ofdm_errors;
+        as->last_cck_errors = as->cck_errors;
+        as->last_listen = as->listen_time;
+
+        as->ofdm_errors = 0;
+        as->cck_errors = 0;
+        as->listen_time = 0;
+}
+
+
+/**
+ * ath5k_ani_calibration() - The main ANI calibration function
+ *
+ * We count OFDM and CCK errors relative to the time where we did not send or
+ * receive ("listen" time) and raise or lower immunity accordingly.
+ * This is called regularly (every second) from the calibration timer, but also
+ * when an error threshold has been reached.
+ *
+ * In order to synchronize access from different contexts, this should be
+ * called only indirectly by scheduling the ANI tasklet!
+ */
+void
+ath5k_ani_calibration(struct ath5k_hw *ah)
+{
+        struct ath5k_ani_state *as = &ah->ah_sc->ani_state;
+        int listen, ofdm_high, ofdm_low, cck_high, cck_low;
+
+        if (as->ani_mode != ATH5K_ANI_MODE_AUTO)
+                return;
+
+        /* get listen time since last call and add it to the counter because we
+         * might not have restarted the "ani period" last time */
+        listen = ath5k_hw_ani_get_listen_time(ah, as);
+        as->listen_time += listen;
+
+        ath5k_ani_save_and_clear_phy_errors(ah, as);
+
+        ofdm_high = as->listen_time * ATH5K_ANI_OFDM_TRIG_HIGH / 1000;
+        cck_high = as->listen_time * ATH5K_ANI_CCK_TRIG_HIGH / 1000;
+        ofdm_low = as->listen_time * ATH5K_ANI_OFDM_TRIG_LOW / 1000;
+        cck_low = as->listen_time * ATH5K_ANI_CCK_TRIG_LOW / 1000;
+
+        ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI,
+                "listen %d (now %d)", as->listen_time, listen);
+        ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI,
+                "check high ofdm %d/%d cck %d/%d",
+                as->ofdm_errors, ofdm_high, as->cck_errors, cck_high);
+
+        if (as->ofdm_errors > ofdm_high || as->cck_errors > cck_high) {
+                /* too many PHY errors - we have to raise immunity */
+                bool ofdm_flag = as->ofdm_errors > ofdm_high ? true : false;
+                ath5k_ani_raise_immunity(ah, as, ofdm_flag);
+                ath5k_ani_period_restart(ah, as);
+
+        } else if (as->listen_time > 5 * ATH5K_ANI_LISTEN_PERIOD) {
+                /* If more than 5 (TODO: why 5?) periods have passed and we got
+                 * relatively little errors we can try to lower immunity */
+                ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI,
+                        "check low ofdm %d/%d cck %d/%d",
+                        as->ofdm_errors, ofdm_low, as->cck_errors, cck_low);
+
+                if (as->ofdm_errors <= ofdm_low && as->cck_errors <= cck_low)
+                        ath5k_ani_lower_immunity(ah, as);
+
+                ath5k_ani_period_restart(ah, as);
+        }
+}
+
+
+/*** INTERRUPT HANDLER ***/
+
+/**
+ * ath5k_ani_mib_intr() - Interrupt handler for ANI MIB counters
+ *
+ * Just read & reset the registers quickly, so they don't generate more
+ * interrupts, save the counters and schedule the tasklet to decide whether
+ * to raise immunity or not.
+ *
+ * We just need to handle PHY error counters, ath5k_hw_update_mib_counters()
+ * should take care of all "normal" MIB interrupts.
+ */
+void
+ath5k_ani_mib_intr(struct ath5k_hw *ah)
+{
+        struct ath5k_ani_state *as = &ah->ah_sc->ani_state;
+
+        /* nothing to do here if HW does not have PHY error counters - they
+         * can't be the reason for the MIB interrupt then */
+        if (!ah->ah_capabilities.cap_has_phyerr_counters)
+                return;
+
+        /* not in use but clear anyways */
+        ath5k_hw_reg_write(ah, 0, AR5K_OFDM_FIL_CNT);
+        ath5k_hw_reg_write(ah, 0, AR5K_CCK_FIL_CNT);
+
+        if (ah->ah_sc->ani_state.ani_mode != ATH5K_ANI_MODE_AUTO)
+                return;
+
+        /* if one of the errors triggered, we can get a superfluous second
+         * interrupt, even though we have already reset the register. the
+         * function detects that so we can return early */
+        if (ath5k_ani_save_and_clear_phy_errors(ah, as) == 0)
+                return;
+
+        if (as->ofdm_errors > ATH5K_ANI_OFDM_TRIG_HIGH ||
+            as->cck_errors > ATH5K_ANI_CCK_TRIG_HIGH)
+                tasklet_schedule(&ah->ah_sc->ani_tasklet);
+}
+
+
+/**
+ * ath5k_ani_phy_error_report() - Used by older HW to report PHY errors
+ *
+ * This is used by hardware without PHY error counters to report PHY errors
+ * on a frame-by-frame basis, instead of the interrupt.
+ */
+void
+ath5k_ani_phy_error_report(struct ath5k_hw *ah,
+                           enum ath5k_phy_error_code phyerr)
+{
+        struct ath5k_ani_state *as = &ah->ah_sc->ani_state;
+
+        if (phyerr == AR5K_RX_PHY_ERROR_OFDM_TIMING) {
+                as->ofdm_errors++;
+                if (as->ofdm_errors > ATH5K_ANI_OFDM_TRIG_HIGH)
+                        tasklet_schedule(&ah->ah_sc->ani_tasklet);
+        } else if (phyerr == AR5K_RX_PHY_ERROR_CCK_TIMING) {
+                as->cck_errors++;
+                if (as->cck_errors > ATH5K_ANI_CCK_TRIG_HIGH)
+                        tasklet_schedule(&ah->ah_sc->ani_tasklet);
+        }
+}
+
+
+/*** INIT ***/
+
+/**
+ * ath5k_enable_phy_err_counters() - Enable PHY error counters
+ *
+ * Enable PHY error counters for OFDM and CCK timing errors.
+ */
+static void
+ath5k_enable_phy_err_counters(struct ath5k_hw *ah)
+{
+        ath5k_hw_reg_write(ah, ATH5K_PHYERR_CNT_MAX - ATH5K_ANI_OFDM_TRIG_HIGH,
+                           AR5K_PHYERR_CNT1);
+        ath5k_hw_reg_write(ah, ATH5K_PHYERR_CNT_MAX - ATH5K_ANI_CCK_TRIG_HIGH,
+                           AR5K_PHYERR_CNT2);
+        ath5k_hw_reg_write(ah, AR5K_PHY_ERR_FIL_OFDM, AR5K_PHYERR_CNT1_MASK);
+        ath5k_hw_reg_write(ah, AR5K_PHY_ERR_FIL_CCK, AR5K_PHYERR_CNT2_MASK);
+
+        /* not in use */
+        ath5k_hw_reg_write(ah, 0, AR5K_OFDM_FIL_CNT);
+        ath5k_hw_reg_write(ah, 0, AR5K_CCK_FIL_CNT);
+}
+
+
+/**
+ * ath5k_disable_phy_err_counters() - Disable PHY error counters
+ *
+ * Disable PHY error counters for OFDM and CCK timing errors.
+ */
+static void
+ath5k_disable_phy_err_counters(struct ath5k_hw *ah)
+{
+        ath5k_hw_reg_write(ah, 0, AR5K_PHYERR_CNT1);
+        ath5k_hw_reg_write(ah, 0, AR5K_PHYERR_CNT2);
+        ath5k_hw_reg_write(ah, 0, AR5K_PHYERR_CNT1_MASK);
+        ath5k_hw_reg_write(ah, 0, AR5K_PHYERR_CNT2_MASK);
+
+        /* not in use */
+        ath5k_hw_reg_write(ah, 0, AR5K_OFDM_FIL_CNT);
+        ath5k_hw_reg_write(ah, 0, AR5K_CCK_FIL_CNT);
+}
+
+
+/**
+ * ath5k_ani_init() - Initialize ANI
+ * @mode: Which mode to use (auto, manual high, manual low, off)
+ *
+ * Initialize ANI according to mode.
+ */
+void
+ath5k_ani_init(struct ath5k_hw *ah, enum ath5k_ani_mode mode)
+{
+        /* ANI is only possible on 5212 and newer */
+        if (ah->ah_version < AR5K_AR5212)
+                return;
+
+        /* clear old state information */
+        memset(&ah->ah_sc->ani_state, 0, sizeof(ah->ah_sc->ani_state));
+
+        /* older hardware has more spur levels than newer */
+        if (ah->ah_mac_srev < AR5K_SREV_AR2414)
+                ah->ah_sc->ani_state.max_spur_level = 7;
+        else
+                ah->ah_sc->ani_state.max_spur_level = 2;
+
+        /* initial values for our ani parameters */
+        if (mode == ATH5K_ANI_MODE_OFF) {
+                ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI, "ANI off\n");
+        } else if  (mode == ATH5K_ANI_MODE_MANUAL_LOW) {
+                ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI,
+                        "ANI manual low -> high sensitivity\n");
+                ath5k_ani_set_noise_immunity_level(ah, 0);
+                ath5k_ani_set_spur_immunity_level(ah, 0);
+                ath5k_ani_set_firstep_level(ah, 0);
+                ath5k_ani_set_ofdm_weak_signal_detection(ah, true);
+                ath5k_ani_set_cck_weak_signal_detection(ah, true);
+        } else if (mode == ATH5K_ANI_MODE_MANUAL_HIGH) {
+                ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI,
+                        "ANI manual high -> low sensitivity\n");
+                ath5k_ani_set_noise_immunity_level(ah,
+                                        ATH5K_ANI_MAX_NOISE_IMM_LVL);
+                ath5k_ani_set_spur_immunity_level(ah,
+                                        ah->ah_sc->ani_state.max_spur_level);
+                ath5k_ani_set_firstep_level(ah, ATH5K_ANI_MAX_FIRSTEP_LVL);
+                ath5k_ani_set_ofdm_weak_signal_detection(ah, false);
+                ath5k_ani_set_cck_weak_signal_detection(ah, false);
+        } else if (mode == ATH5K_ANI_MODE_AUTO) {
+                ATH5K_DBG_UNLIMIT(ah->ah_sc, ATH5K_DEBUG_ANI, "ANI auto\n");
+                ath5k_ani_set_noise_immunity_level(ah, 0);
+                ath5k_ani_set_spur_immunity_level(ah, 0);
+                ath5k_ani_set_firstep_level(ah, 0);
+                ath5k_ani_set_ofdm_weak_signal_detection(ah, true);
+                ath5k_ani_set_cck_weak_signal_detection(ah, false);
+        }
+
+        /* newer hardware has PHY error counter registers which we can use to
+         * get OFDM and CCK error counts. older hardware has to set rxfilter and
+         * report every single PHY error by calling ath5k_ani_phy_error_report()
+         */
+        if (mode == ATH5K_ANI_MODE_AUTO) {
+                if (ah->ah_capabilities.cap_has_phyerr_counters)
+                        ath5k_enable_phy_err_counters(ah);
+                else
+                        ath5k_hw_set_rx_filter(ah, ath5k_hw_get_rx_filter(ah) |
+                                                   AR5K_RX_FILTER_PHYERR);
+        } else {
+                if (ah->ah_capabilities.cap_has_phyerr_counters)
+                        ath5k_disable_phy_err_counters(ah);
+                else
+                        ath5k_hw_set_rx_filter(ah, ath5k_hw_get_rx_filter(ah) &
+                                                   ~AR5K_RX_FILTER_PHYERR);
+        }
+
+        ah->ah_sc->ani_state.ani_mode = mode;
+}
+
+
+/*** DEBUG ***/
+
+#ifdef CONFIG_ATH5K_DEBUG
+
+void
+ath5k_ani_print_counters(struct ath5k_hw *ah)
+{
+        /* clears too */
+        printk(KERN_NOTICE "ACK fail\t%d\n",
+                ath5k_hw_reg_read(ah, AR5K_ACK_FAIL));
+        printk(KERN_NOTICE "RTS fail\t%d\n",
+                ath5k_hw_reg_read(ah, AR5K_RTS_FAIL));
+        printk(KERN_NOTICE "RTS success\t%d\n",
+                ath5k_hw_reg_read(ah, AR5K_RTS_OK));
+        printk(KERN_NOTICE "FCS error\t%d\n",
+                ath5k_hw_reg_read(ah, AR5K_FCS_FAIL));
+
+        /* no clear */
+        printk(KERN_NOTICE "tx\t%d\n",
+                ath5k_hw_reg_read(ah, AR5K_PROFCNT_TX));
+        printk(KERN_NOTICE "rx\t%d\n",
+                ath5k_hw_reg_read(ah, AR5K_PROFCNT_RX));
+        printk(KERN_NOTICE "busy\t%d\n",
+                ath5k_hw_reg_read(ah, AR5K_PROFCNT_RXCLR));
+        printk(KERN_NOTICE "cycles\t%d\n",
+                ath5k_hw_reg_read(ah, AR5K_PROFCNT_CYCLE));
+
+        printk(KERN_NOTICE "AR5K_PHYERR_CNT1\t%d\n",
+                ath5k_hw_reg_read(ah, AR5K_PHYERR_CNT1));
+        printk(KERN_NOTICE "AR5K_PHYERR_CNT2\t%d\n",
+                ath5k_hw_reg_read(ah, AR5K_PHYERR_CNT2));
+        printk(KERN_NOTICE "AR5K_OFDM_FIL_CNT\t%d\n",
+                ath5k_hw_reg_read(ah, AR5K_OFDM_FIL_CNT));
+        printk(KERN_NOTICE "AR5K_CCK_FIL_CNT\t%d\n",
+                ath5k_hw_reg_read(ah, AR5K_CCK_FIL_CNT));
+}
+
+#endif