/*
 * 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include "ath5k.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
 * @ah: The &struct ath5k_hw
 * @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 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
        static const s8 lo[] = { -52, -56, -60, -64, -70 };
        static const s8 hi[] = { -18, -18, -16, -14, -12 };
        static const s8 sz[] = { -34, -41, -48, -55, -62 };
        static const s8 fr[] = { -70, -72, -75, -78, -80 };
#else
        static const s8 lo[] = { -64, -70 };
        static const s8 hi[] = { -14, -12 };
        static const s8 sz[] = { -55, -62 };
        static const s8 fr[] = { -78, -80 };
#endif
        if (level < 0 || level >= ARRAY_SIZE(sz)) {
                ATH5K_ERR(ah, "noise immunity level %d out of range",
                          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->ani_state.noise_imm_level = level;
        ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "new level %d", level);
}

/**
 * ath5k_ani_set_spur_immunity_level() - Set spur immunity level
 * @ah: The &struct ath5k_hw
 * @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)
{
        static const int val[] = { 2, 4, 6, 8, 10, 12, 14, 16 };

        if (level < 0 || level >= ARRAY_SIZE(val) ||
            level > ah->ani_state.max_spur_level) {
                ATH5K_ERR(ah, "spur immunity level %d out of range",
                          level);
                return;
        }

        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_OFDM_SELFCORR,
                AR5K_PHY_OFDM_SELFCORR_CYPWR_THR1, val[level]);

        ah->ani_state.spur_level = level;
        ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "new level %d", level);
}

/**
 * ath5k_ani_set_firstep_level() - Set "firstep" level
 * @ah: The &struct ath5k_hw
 * @level: level between 0 and @ATH5K_ANI_MAX_FIRSTEP_LVL
 */
void
ath5k_ani_set_firstep_level(struct ath5k_hw *ah, int level)
{
        static const int val[] = { 0, 4, 8 };

        if (level < 0 || level >= ARRAY_SIZE(val)) {
                ATH5K_ERR(ah, "firstep level %d out of range", level);
                return;
        }

        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_SIG,
                                AR5K_PHY_SIG_FIRSTEP, val[level]);

        ah->ani_state.firstep_level = level;
        ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "new level %d", level);
}

/**
 * ath5k_ani_set_ofdm_weak_signal_detection() - Set OFDM weak signal detection
 * @ah: The &struct ath5k_hw
 * @on: turn on or off
 */
void
ath5k_ani_set_ofdm_weak_signal_detection(struct ath5k_hw *ah, bool on)
{
        static const int m1l[] = { 127, 50 };
        static const int m2l[] = { 127, 40 };
        static const int m1[] = { 127, 0x4d };
        static const int m2[] = { 127, 0x40 };
        static const int m2cnt[] = { 31, 16 };
        static 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->ani_state.ofdm_weak_sig = on;
        ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "turned %s",
                          on ? "on" : "off");
}

/**
 * ath5k_ani_set_cck_weak_signal_detection() - Set CCK weak signal detection
 * @ah: The &struct ath5k_hw
 * @on: turn on or off
 */
void
ath5k_ani_set_cck_weak_signal_detection(struct ath5k_hw *ah, bool on)
{
        static const int val[] = { 8, 6 };
        AR5K_REG_WRITE_BITS(ah, AR5K_PHY_CCK_CROSSCORR,
                                AR5K_PHY_CCK_CROSSCORR_WEAK_SIG_THR, val[on]);
        ah->ani_state.cck_weak_sig = on;
        ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "turned %s",
                          on ? "on" : "off");
}


/***************\
* ANI algorithm *
\***************/

/**
 * ath5k_ani_raise_immunity() - Increase noise immunity
 * @ah: The &struct ath5k_hw
 * @as: The &struct ath5k_ani_state
 * @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 = ewma_read(&ah->ah_beacon_rssi_avg);

        ATH5K_DBG_UNLIMIT(ah, 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->ani_state.max_spur_level) {
                ath5k_ani_set_spur_immunity_level(ah, as->spur_level + 1);
                return;
        }

        /* AP mode */
        if (ah->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, 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) {
                        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, ATH5K_DEBUG_ANI,
                                  "beacon RSSI mid");
                if (ofdm_trigger && !as->ofdm_weak_sig)
                        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, ATH5K_DEBUG_ANI,
                                  "beacon RSSI low, 2GHz");
                if (ofdm_trigger && as->ofdm_weak_sig)
                        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
 * @ah: The &struct ath5k_hw
 * @as: The &struct ath5k_ani_state
 *
 * 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 = ewma_read(&ah->ah_beacon_rssi_avg);

        ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "lower immunity");

        if (ah->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) {
                                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() - Update counters and return listening time
 * @ah: The &struct ath5k_hw
 * @as: The &struct ath5k_ani_state
 *
 * Return an approximation of the time spent "listening" in milliseconds (ms)
 * since the last call of this function.
 * Save a snapshot of the counter values for debugging/statistics.
 */
static int
ath5k_hw_ani_get_listen_time(struct ath5k_hw *ah, struct ath5k_ani_state *as)
{
        struct ath_common *common = ath5k_hw_common(ah);
        int listen;

        spin_lock_bh(&common->cc_lock);

        ath_hw_cycle_counters_update(common);
        memcpy(&as->last_cc, &common->cc_ani, sizeof(as->last_cc));

        /* clears common->cc_ani */
        listen = ath_hw_get_listen_time(common);

        spin_unlock_bh(&common->cc_lock);

        return listen;
}

/**
 * ath5k_ani_save_and_clear_phy_errors() - Clear and save PHY error counters
 * @ah: The &struct ath5k_hw
 * @as: The &struct ath5k_ani_state
 *
 * 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
 * @as: The &struct ath5k_ani_state
 *
 * Just reset counters, so they are clear for the next "ani period".
 */
static void
ath5k_ani_period_restart(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
 * @ah: The &struct ath5k_hw
 *
 * 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->ani_state;
        int listen, ofdm_high, ofdm_low, cck_high, cck_low;

        /* get listen time since last call and add it to the counter because we
         * might not have restarted the "ani period" last time.
         * always do this to calculate the busy time also in manual mode */
        listen = ath5k_hw_ani_get_listen_time(ah, as);
        as->listen_time += listen;

        if (as->ani_mode != ATH5K_ANI_MODE_AUTO)
                return;

        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, ATH5K_DEBUG_ANI,
                "listen %d (now %d)", as->listen_time, listen);
        ATH5K_DBG_UNLIMIT(ah, 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(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, 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(as);
        }
}


/*******************\
* Interrupt handler *
\*******************/

/**
 * ath5k_ani_mib_intr() - Interrupt handler for ANI MIB counters
 * @ah: The &struct ath5k_hw
 *
 * 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->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->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->ani_tasklet);
}

/**
 * ath5k_ani_phy_error_report - Used by older HW to report PHY errors
 *
 * @ah: The &struct ath5k_hw
 * @phyerr: One of enum ath5k_phy_error_code
 *
 * 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->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->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->ani_tasklet);
        }
}


/****************\
* Initialization *
\****************/

/**
 * ath5k_enable_phy_err_counters() - Enable PHY error counters
 * @ah: The &struct ath5k_hw
 *
 * 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
 * @ah: The &struct ath5k_hw
 *
 * 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
 * @ah: The &struct ath5k_hw
 * @mode: One of enum ath5k_ani_mode
 *
 * 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;

        if (mode < ATH5K_ANI_MODE_OFF || mode > ATH5K_ANI_MODE_AUTO) {
                ATH5K_ERR(ah, "ANI mode %d out of range", mode);
                return;
        }

        /* clear old state information */
        memset(&ah->ani_state, 0, sizeof(ah->ani_state));

        /* older hardware has more spur levels than newer */
        if (ah->ah_mac_srev < AR5K_SREV_AR2414)
                ah->ani_state.max_spur_level = 7;
        else
                ah->ani_state.max_spur_level = 2;

        /* initial values for our ani parameters */
        if (mode == ATH5K_ANI_MODE_OFF) {
                ATH5K_DBG_UNLIMIT(ah, ATH5K_DEBUG_ANI, "ANI off\n");
        } else if (mode == ATH5K_ANI_MODE_MANUAL_LOW) {
                ATH5K_DBG_UNLIMIT(ah, 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, 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->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, 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->ani_state.ani_mode = mode;
}


/**************\
* Debug output *
\**************/

#ifdef CONFIG_ATH5K_DEBUG

/**
 * ath5k_ani_print_counters() - Print ANI counters
 * @ah: The &struct ath5k_hw
 *
 * Used for debugging ANI
 */
void
ath5k_ani_print_counters(struct ath5k_hw *ah)
{
        /* clears too */
        pr_notice("ACK fail\t%d\n", ath5k_hw_reg_read(ah, AR5K_ACK_FAIL));
        pr_notice("RTS fail\t%d\n", ath5k_hw_reg_read(ah, AR5K_RTS_FAIL));
        pr_notice("RTS success\t%d\n", ath5k_hw_reg_read(ah, AR5K_RTS_OK));
        pr_notice("FCS error\t%d\n", ath5k_hw_reg_read(ah, AR5K_FCS_FAIL));

        /* no clear */
        pr_notice("tx\t%d\n", ath5k_hw_reg_read(ah, AR5K_PROFCNT_TX));
        pr_notice("rx\t%d\n", ath5k_hw_reg_read(ah, AR5K_PROFCNT_RX));
        pr_notice("busy\t%d\n", ath5k_hw_reg_read(ah, AR5K_PROFCNT_RXCLR));
        pr_notice("cycles\t%d\n", ath5k_hw_reg_read(ah, AR5K_PROFCNT_CYCLE));

        pr_notice("AR5K_PHYERR_CNT1\t%d\n",
                  ath5k_hw_reg_read(ah, AR5K_PHYERR_CNT1));
        pr_notice("AR5K_PHYERR_CNT2\t%d\n",
                  ath5k_hw_reg_read(ah, AR5K_PHYERR_CNT2));
        pr_notice("AR5K_OFDM_FIL_CNT\t%d\n",
                  ath5k_hw_reg_read(ah, AR5K_OFDM_FIL_CNT));
        pr_notice("AR5K_CCK_FIL_CNT\t%d\n",
                  ath5k_hw_reg_read(ah, AR5K_CCK_FIL_CNT));
}

#endif