/*
 * Copyright (c) 1996, 2003 VIA Networking Technologies, Inc.
 * All rights reserved.
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * File: datarate.c
 *
 * Purpose: Handles the auto fallback & data rates functions
 *
 * Author: Lyndon Chen
 *
 * Date: July 17, 2002
 *
 * Functions:
 *      RATEvParseMaxRate - Parsing the highest basic & support rate in rate field of frame
 *      RATEvTxRateFallBack - Rate fallback Algorithm Implementaion
 *      RATEuSetIE- Set rate IE field.
 *
 * Revision History:
 *
 */

#include "ttype.h"
#include "tmacro.h"
#include "mac.h"
#include "80211mgr.h"
#include "bssdb.h"
#include "datarate.h"
#include "card.h"
#include "baseband.h"
#include "srom.h"

/*---------------------  Static Definitions -------------------------*/

/*---------------------  Static Classes  ----------------------------*/

extern unsigned short TxRate_iwconfig; //2008-5-8 <add> by chester
/*---------------------  Static Variables  --------------------------*/
//static int          msglevel                =MSG_LEVEL_DEBUG;
static int msglevel = MSG_LEVEL_INFO;
const unsigned char acbyIERate[MAX_RATE] =
{0x02, 0x04, 0x0B, 0x16, 0x0C, 0x12, 0x18, 0x24, 0x30, 0x48, 0x60, 0x6C};

#define AUTORATE_TXOK_CNT       0x0400
#define AUTORATE_TXFAIL_CNT     0x0064
#define AUTORATE_TIMEOUT        10

/*---------------------  Static Functions  --------------------------*/

void s_vResetCounter(
        PKnownNodeDB psNodeDBTable
);

void
s_vResetCounter(
        PKnownNodeDB psNodeDBTable
)
{
        unsigned char ii;

        // clear statistic counter for auto_rate
        for (ii = 0; ii <= MAX_RATE; ii++) {
                psNodeDBTable->uTxOk[ii] = 0;
                psNodeDBTable->uTxFail[ii] = 0;
        }
}

/*---------------------  Export Variables  --------------------------*/

/*---------------------  Export Functions  --------------------------*/

/*+
 *
 * Description:
 *      Get RateIdx from the value in SuppRates IE or ExtSuppRates IE
 *
 * Parameters:
 *  In:
 *      unsigned char - Rate value in SuppRates IE or ExtSuppRates IE
 *  Out:
 *      none
 *
 * Return Value: RateIdx
 *
 -*/
unsigned char
DATARATEbyGetRateIdx(
        unsigned char byRate
)
{
        unsigned char ii;

        //Erase basicRate flag.
        byRate = byRate & 0x7F;//0111 1111

        for (ii = 0; ii < MAX_RATE; ii++) {
                if (acbyIERate[ii] == byRate)
                        return ii;
        }
        return 0;
}

/*+
 *
 * Routine Description:
 *      Rate fallback Algorithm Implementation
 *
 * Parameters:
 *  In:
 *      pDevice         - Pointer to the adapter
 *      psNodeDBTable   - Pointer to Node Data Base
 *  Out:
 *      none
 *
 * Return Value: none
 *
 -*/
#define AUTORATE_TXCNT_THRESHOLD        20
#define AUTORATE_INC_THRESHOLD          30

/*+
 *
 * Description:
 *      Get RateIdx from the value in SuppRates IE or ExtSuppRates IE
 *
 * Parameters:
 *  In:
 *      unsigned char - Rate value in SuppRates IE or ExtSuppRates IE
 *  Out:
 *      none
 *
 * Return Value: RateIdx
 *
 -*/
unsigned short
wGetRateIdx(
        unsigned char byRate
)
{
        unsigned short ii;

        //Erase basicRate flag.
        byRate = byRate & 0x7F;//0111 1111

        for (ii = 0; ii < MAX_RATE; ii++) {
                if (acbyIERate[ii] == byRate)
                        return ii;
        }
        return 0;
}

/*+
 *
 * Description:
 *      Parsing the highest basic & support rate in rate field of frame.
 *
 * Parameters:
 *  In:
 *      pDevice         - Pointer to the adapter
 *      pItemRates      - Pointer to Rate field defined in 802.11 spec.
 *      pItemExtRates      - Pointer to Extended Rate field defined in 802.11 spec.
 *  Out:
 *      pwMaxBasicRate  - Maximum Basic Rate
 *      pwMaxSuppRate   - Maximum Supported Rate
 *      pbyTopCCKRate   - Maximum Basic Rate in CCK mode
 *      pbyTopOFDMRate  - Maximum Basic Rate in OFDM mode
 *
 * Return Value: none
 *
 -*/
void
RATEvParseMaxRate(
        void *pDeviceHandler,
        PWLAN_IE_SUPP_RATES pItemRates,
        PWLAN_IE_SUPP_RATES pItemExtRates,
        bool bUpdateBasicRate,
        unsigned short *pwMaxBasicRate,
        unsigned short *pwMaxSuppRate,
        unsigned short *pwSuppRate,
        unsigned char *pbyTopCCKRate,
        unsigned char *pbyTopOFDMRate
)
{
        PSDevice  pDevice = (PSDevice) pDeviceHandler;
        unsigned int ii;
        unsigned char byHighSuppRate = 0;
        unsigned char byRate = 0;
        unsigned short wOldBasicRate = pDevice->wBasicRate;
        unsigned int uRateLen;

        if (pItemRates == NULL)
                return;

        *pwSuppRate = 0;
        uRateLen = pItemRates->len;

        DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "ParseMaxRate Len: %d\n", uRateLen);
        if (pDevice->eCurrentPHYType != PHY_TYPE_11B) {
                if (uRateLen > WLAN_RATES_MAXLEN)
                        uRateLen = WLAN_RATES_MAXLEN;
        } else {
                if (uRateLen > WLAN_RATES_MAXLEN_11B)
                        uRateLen = WLAN_RATES_MAXLEN_11B;
        }

        for (ii = 0; ii < uRateLen; ii++) {
                byRate = (unsigned char)(pItemRates->abyRates[ii]);
                if (WLAN_MGMT_IS_BASICRATE(byRate) && bUpdateBasicRate)  {
                        // Add to basic rate set, update pDevice->byTopCCKBasicRate and pDevice->byTopOFDMBasicRate
                        CARDbAddBasicRate((void *)pDevice, wGetRateIdx(byRate));
                        DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "ParseMaxRate AddBasicRate: %d\n", wGetRateIdx(byRate));
                }
                byRate = (unsigned char)(pItemRates->abyRates[ii]&0x7F);
                if (byHighSuppRate == 0)
                        byHighSuppRate = byRate;
                if (byRate > byHighSuppRate)
                        byHighSuppRate = byRate;
                *pwSuppRate |= (1<<wGetRateIdx(byRate));
        }
        if ((pItemExtRates != NULL) && (pItemExtRates->byElementID == WLAN_EID_EXTSUPP_RATES) &&
            (pDevice->eCurrentPHYType != PHY_TYPE_11B)) {
                unsigned int uExtRateLen = pItemExtRates->len;

                if (uExtRateLen > WLAN_RATES_MAXLEN)
                        uExtRateLen = WLAN_RATES_MAXLEN;

                for (ii = 0; ii < uExtRateLen; ii++) {
                        byRate = (unsigned char)(pItemExtRates->abyRates[ii]);
                        // select highest basic rate
                        if (WLAN_MGMT_IS_BASICRATE(pItemExtRates->abyRates[ii])) {
                                // Add to basic rate set, update pDevice->byTopCCKBasicRate and pDevice->byTopOFDMBasicRate
                                CARDbAddBasicRate((void *)pDevice, wGetRateIdx(byRate));
                                DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "ParseMaxRate AddBasicRate: %d\n", wGetRateIdx(byRate));
                        }
                        byRate = (unsigned char)(pItemExtRates->abyRates[ii]&0x7F);
                        if (byHighSuppRate == 0)
                                byHighSuppRate = byRate;
                        if (byRate > byHighSuppRate)
                                byHighSuppRate = byRate;
                        *pwSuppRate |= (1<<wGetRateIdx(byRate));
                        //DBG_PRN_GRP09(("ParseMaxRate : HighSuppRate: %d, %X\n", wGetRateIdx(byRate), byRate));
                }
        } //if (pItemExtRates != NULL)

        if ((pDevice->byPacketType == PK_TYPE_11GB) && CARDbIsOFDMinBasicRate((void *)pDevice)) {
                pDevice->byPacketType = PK_TYPE_11GA;
        }

        *pbyTopCCKRate = pDevice->byTopCCKBasicRate;
        *pbyTopOFDMRate = pDevice->byTopOFDMBasicRate;
        *pwMaxSuppRate = wGetRateIdx(byHighSuppRate);
        if ((pDevice->byPacketType == PK_TYPE_11B) || (pDevice->byPacketType == PK_TYPE_11GB))
                *pwMaxBasicRate = pDevice->byTopCCKBasicRate;
        else
                *pwMaxBasicRate = pDevice->byTopOFDMBasicRate;
        if (wOldBasicRate != pDevice->wBasicRate)
                CARDvSetRSPINF((void *)pDevice, pDevice->eCurrentPHYType);

        DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "Exit ParseMaxRate\n");
}

/*+
 *
 * Routine Description:
 *      Rate fallback Algorithm Implementaion
 *
 * Parameters:
 *  In:
 *      pDevice         - Pointer to the adapter
 *      psNodeDBTable   - Pointer to Node Data Base
 *  Out:
 *      none
 *
 * Return Value: none
 *
 -*/
#define AUTORATE_TXCNT_THRESHOLD        20
#define AUTORATE_INC_THRESHOLD          30

void
RATEvTxRateFallBack(
        void *pDeviceHandler,
        PKnownNodeDB psNodeDBTable
)
{
        PSDevice        pDevice = (PSDevice) pDeviceHandler;
        unsigned short wIdxDownRate = 0;
        unsigned int ii;
//unsigned long dwRateTable[MAX_RATE]  = {1,   2,   5,   11,  6,    9,    12,   18,  24,  36,  48,  54};
        bool bAutoRate[MAX_RATE]    = {true, true, true, true, false, false, true, true, true, true, true, true};
        unsigned long dwThroughputTbl[MAX_RATE] = {10, 20, 55, 110, 60, 90, 120, 180, 240, 360, 480, 540};
        unsigned long dwThroughput = 0;
        unsigned short wIdxUpRate = 0;
        unsigned long dwTxDiff = 0;

        if (pDevice->pMgmt->eScanState != WMAC_NO_SCANNING) {
                // Don't do Fallback when scanning Channel
                return;
        }

        psNodeDBTable->uTimeCount++;

        if (psNodeDBTable->uTxFail[MAX_RATE] > psNodeDBTable->uTxOk[MAX_RATE])
                dwTxDiff = psNodeDBTable->uTxFail[MAX_RATE] - psNodeDBTable->uTxOk[MAX_RATE];

        if ((psNodeDBTable->uTxOk[MAX_RATE] < AUTORATE_TXOK_CNT) &&
            (dwTxDiff < AUTORATE_TXFAIL_CNT) &&
            (psNodeDBTable->uTimeCount < AUTORATE_TIMEOUT)) {
                return;
        }

        if (psNodeDBTable->uTimeCount >= AUTORATE_TIMEOUT) {
                psNodeDBTable->uTimeCount = 0;
        }

        for (ii = 0; ii < MAX_RATE; ii++) {
                if (psNodeDBTable->wSuppRate & (0x0001<<ii)) {
                        if (bAutoRate[ii]) {
                                wIdxUpRate = (unsigned short) ii;
                        }
                } else {
                        bAutoRate[ii] = false;
                }
        }

        for (ii = 0; ii <= psNodeDBTable->wTxDataRate; ii++) {
                if ((psNodeDBTable->uTxOk[ii] != 0) ||
                    (psNodeDBTable->uTxFail[ii] != 0)) {
                        dwThroughputTbl[ii] *= psNodeDBTable->uTxOk[ii];
                        if (ii < RATE_11M) {
                                psNodeDBTable->uTxFail[ii] *= 4;
                        }
                        dwThroughputTbl[ii] /= (psNodeDBTable->uTxOk[ii] + psNodeDBTable->uTxFail[ii]);
                }
//        DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "Rate %d,Ok: %d, Fail:%d, Throughput:%d\n",
//                       ii, psNodeDBTable->uTxOk[ii], psNodeDBTable->uTxFail[ii], dwThroughputTbl[ii]);
        }
        dwThroughput = dwThroughputTbl[psNodeDBTable->wTxDataRate];

        wIdxDownRate = psNodeDBTable->wTxDataRate;
        for (ii = psNodeDBTable->wTxDataRate; ii > 0;) {
                ii--;
                if ((dwThroughputTbl[ii] > dwThroughput) && bAutoRate[ii]) {
                        dwThroughput = dwThroughputTbl[ii];
                        wIdxDownRate = (unsigned short) ii;
                }
        }
        psNodeDBTable->wTxDataRate = wIdxDownRate;
        if (psNodeDBTable->uTxOk[MAX_RATE]) {
                if (psNodeDBTable->uTxOk[MAX_RATE] >
                    (psNodeDBTable->uTxFail[MAX_RATE] * 4)) {
                        psNodeDBTable->wTxDataRate = wIdxUpRate;
                }
        } else { // adhoc, if uTxOk =0 & uTxFail = 0
                if (psNodeDBTable->uTxFail[MAX_RATE] == 0)
                        psNodeDBTable->wTxDataRate = wIdxUpRate;
        }
//2008-5-8 <add> by chester
        TxRate_iwconfig = psNodeDBTable->wTxDataRate;
        s_vResetCounter(psNodeDBTable);
//    DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO "Rate: %d, U:%d, D:%d\n", psNodeDBTable->wTxDataRate, wIdxUpRate, wIdxDownRate);

        return;
}

/*+
 *
 * Description:
 *    This routine is used to assemble available Rate IE.
 *
 * Parameters:
 *  In:
 *    pDevice
 *  Out:
 *
 * Return Value: None
 *
 -*/
unsigned char
RATEuSetIE(
        PWLAN_IE_SUPP_RATES pSrcRates,
        PWLAN_IE_SUPP_RATES pDstRates,
        unsigned int uRateLen
)
{
        unsigned int ii, uu, uRateCnt = 0;

        if ((pSrcRates == NULL) || (pDstRates == NULL))
                return 0;

        if (pSrcRates->len == 0)
                return 0;

        for (ii = 0; ii < uRateLen; ii++) {
                for (uu = 0; uu < pSrcRates->len; uu++) {
                        if ((pSrcRates->abyRates[uu] & 0x7F) == acbyIERate[ii]) {
                                pDstRates->abyRates[uRateCnt++] = pSrcRates->abyRates[uu];
                                break;
                        }
                }
        }
        return (unsigned char)uRateCnt;
}