/*
 * 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 == true))  {
            // 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] == true) {
                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]==true) ) {
            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;
}