/*      $NetBSD: athrate-sample.h,v 1.4 2012/11/08 20:43:55 dyoung Exp $ */

/*-
 * Copyright (c) 2005 John Bicket
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer,
 *    without modification.
 * 2. Redistributions in binary form must reproduce at minimum a disclaimer
 *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
 *    redistribution must be conditioned upon including a substantially
 *    similar Disclaimer requirement for further binary redistribution.
 * 3. Neither the names of the above-listed copyright holders nor the names
 *    of any contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * NO WARRANTY
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
 * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
 * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGES.
 *
 * $FreeBSD: src/sys/dev/ath/ath_rate/sample/sample.h,v 1.3 2005/03/20 01:27:33 sam Exp $
 */

/*
 * Defintions for the Atheros Wireless LAN controller driver.
 */
#ifndef _DEV_ATH_RATE_SAMPLE_H
#define _DEV_ATH_RATE_SAMPLE_H

/* per-device state */
struct sample_softc {
        struct ath_ratectrl arc;        /* base state */
        int     ath_smoothing_rate;     /* ewma percentage (out of 100) */
        int     ath_sample_rate;        /* send a different bit-rate 1/X packets */
};
#define ATH_SOFTC_SAMPLE(sc)    ((struct sample_softc *)sc->sc_rc)

struct rate_info {
        int rate;
        int rix;
        int rateCode;
        int shortPreambleRateCode;
};


struct rate_stats {     
        unsigned average_tx_time;
        int successive_failures;
        int tries;
        int total_packets;
        int packets_acked;
        unsigned perfect_tx_time; /* transmit time for 0 retries */
        int last_tx;
};

/*
 * for now, we track performance for three different packet
 * size buckets
 */
#define NUM_PACKET_SIZE_BINS 3
static int packet_size_bins[NUM_PACKET_SIZE_BINS] = {250, 1600, 3000};

/* per-node state */
struct sample_node {
        int static_rate_ndx;
        int num_rates;

        struct rate_info rates[IEEE80211_RATE_MAXSIZE];
        
        struct rate_stats stats[NUM_PACKET_SIZE_BINS][IEEE80211_RATE_MAXSIZE];
        int last_sample_ndx[NUM_PACKET_SIZE_BINS];

        int current_sample_ndx[NUM_PACKET_SIZE_BINS];       
        int packets_sent[NUM_PACKET_SIZE_BINS];

        int current_rate[NUM_PACKET_SIZE_BINS];
        int packets_since_switch[NUM_PACKET_SIZE_BINS];
        unsigned ticks_since_switch[NUM_PACKET_SIZE_BINS];

        int packets_since_sample[NUM_PACKET_SIZE_BINS];
        unsigned sample_tt[NUM_PACKET_SIZE_BINS];
};
#define ATH_NODE_SAMPLE(an)     ((struct sample_node *)&an[1])

#ifndef MIN
#define MIN(a,b)        ((a) < (b) ? (a) : (b))
#endif
#ifndef MAX
#define MAX(a,b)        ((a) > (b) ? (a) : (b))
#endif

#define WIFI_CW_MIN 31
#define WIFI_CW_MAX 1023

struct ar5212_desc {
        /*
         * tx_control_0
         */
        u_int32_t       frame_len:12;
        u_int32_t       reserved_12_15:4;
        u_int32_t       xmit_power:6;
        u_int32_t       rts_cts_enable:1;
        u_int32_t       veol:1;
        u_int32_t       clear_dest_mask:1;
        u_int32_t       ant_mode_xmit:4;
        u_int32_t       inter_req:1;
        u_int32_t       encrypt_key_valid:1;
        u_int32_t       cts_enable:1;

        /*
         * tx_control_1
         */
        u_int32_t       buf_len:12;
        u_int32_t       more:1;
        u_int32_t       encrypt_key_index:7;
        u_int32_t       frame_type:4;
        u_int32_t       no_ack:1;
        u_int32_t       comp_proc:2;
        u_int32_t       comp_iv_len:2;
        u_int32_t       comp_icv_len:2;
        u_int32_t       reserved_31:1;

        /*
         * tx_control_2
         */
        u_int32_t       rts_duration:15;
        u_int32_t       duration_update_enable:1;
        u_int32_t       xmit_tries0:4;
        u_int32_t       xmit_tries1:4;
        u_int32_t       xmit_tries2:4;
        u_int32_t       xmit_tries3:4;

        /*
         * tx_control_3
         */
        u_int32_t       xmit_rate0:5;
        u_int32_t       xmit_rate1:5;
        u_int32_t       xmit_rate2:5;
        u_int32_t       xmit_rate3:5;
        u_int32_t       rts_cts_rate:5;
        u_int32_t       reserved_25_31:7;

        /*
         * tx_status_0
         */
        u_int32_t       frame_xmit_ok:1;
        u_int32_t       excessive_retries:1;
        u_int32_t       fifo_underrun:1;
        u_int32_t       filtered:1;
        u_int32_t       rts_fail_count:4;
        u_int32_t       data_fail_count:4;
        u_int32_t       virt_coll_count:4;
        u_int32_t       send_timestamp:16;

        /*
         * tx_status_1
         */
        u_int32_t       done:1;
        u_int32_t       seq_num:12;
        u_int32_t       ack_sig_strength:8;
        u_int32_t       final_ts_index:2;
        u_int32_t       comp_success:1;
        u_int32_t       xmit_antenna:1;
        u_int32_t       reserved_25_31_x:7;
} __packed;

/*
 * Calculate the transmit duration of a frame.
 */
static unsigned calc_usecs_unicast_packet(struct ath_softc *sc,
                                int length, 
                                int rix, int short_retries, int long_retries) {
        const HAL_RATE_TABLE *rt = sc->sc_currates;
        int rts, cts;
        
        unsigned t_slot = 20;
        unsigned t_difs = 50; 
        unsigned t_sifs = 10; 
        struct ieee80211com *ic = &sc->sc_ic;
        int tt = 0;
        int x = 0;
        int cw = WIFI_CW_MIN;
        int cix = rt->info[rix].controlRate;
        
        KASSERTMSG(rt != NULL, "no rate table, mode %u", sc->sc_curmode);

        if (!rt->info[rix].rateKbps) {
                printf("rix %d (%d) bad ratekbps %d mode %u",
                       rix, rt->info[rix].dot11Rate,
                       rt->info[rix].rateKbps,
                       sc->sc_curmode);

                return 0;
        }
        /* 
         * XXX getting mac/phy level timings should be fixed for turbo
         * rates, and there is probably a way to get this from the
         * hal...
         */
        switch (rt->info[rix].phy) {
        case IEEE80211_T_OFDM:
                t_slot = 9;
                t_sifs = 16;
                t_difs = 28;
                /* fall through */
        case IEEE80211_T_TURBO:
                t_slot = 9;
                t_sifs = 8;
                t_difs = 28;
                break;
        case IEEE80211_T_DS:
                /* fall through to default */
        default:
                /* pg 205 ieee.802.11.pdf */
                t_slot = 20;
                t_difs = 50;
                t_sifs = 10;
        }

        rts = cts = 0;

        if ((ic->ic_flags & IEEE80211_F_USEPROT) &&
            rt->info[rix].phy == IEEE80211_T_OFDM) {
                if (ic->ic_protmode == IEEE80211_PROT_RTSCTS)
                        rts = 1;
                else if (ic->ic_protmode == IEEE80211_PROT_CTSONLY)
                        cts = 1;

                cix = rt->info[sc->sc_protrix].controlRate;

        }

        if (0 /*length > ic->ic_rtsthreshold */) {
                rts = 1;
        }

        if (rts || cts) {
                int ctsrate = rt->info[cix].rateCode;
                int ctsduration = 0;

                if (!rt->info[cix].rateKbps) {
                        printf("cix %d (%d) bad ratekbps %d mode %u",
                               cix, rt->info[cix].dot11Rate,
                               rt->info[cix].rateKbps,
                               sc->sc_curmode);
                        return 0;
                }

                ctsrate |= rt->info[cix].shortPreamble;
                if (rts)                /* SIFS + CTS */
                        ctsduration += rt->info[cix].spAckDuration;

                ctsduration += ath_hal_computetxtime(sc->sc_ah,
                                                     rt, length, rix, AH_TRUE);

                if (cts)        /* SIFS + ACK */
                        ctsduration += rt->info[cix].spAckDuration;

                tt += (short_retries + 1) * ctsduration;
        }
        tt += t_difs;
        tt += (long_retries+1)*(t_sifs + rt->info[rix].spAckDuration);
        tt += (long_retries+1)*ath_hal_computetxtime(sc->sc_ah, rt, length, 
                                                rix, AH_TRUE);
        for (x = 0; x <= short_retries + long_retries; x++) {
                cw = MIN(WIFI_CW_MAX, (cw + 1) * 2);
                tt += (t_slot * cw/2);
        }
        return tt;
}
#endif /* _DEV_ATH_RATE_SAMPLE_H */