/*
 * 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 "tmacro.h"
#include "mac.h"
#include "80211mgr.h"
#include "bssdb.h"
#include "datarate.h"
#include "card.h"
#include "baseband.h"
#include "rf.h"

/* static int msglevel = MSG_LEVEL_DEBUG; */
static int msglevel = MSG_LEVEL_INFO;
static const u8 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

void s_vResetCounter(PKnownNodeDB psNodeDBTable);

void s_vResetCounter(PKnownNodeDB psNodeDBTable)
{
        u8 ii;

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

/*+
 *
 * 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

/*+
 *
 * Description:
 *      Get RateIdx from the value in SuppRates IE or ExtSuppRates IE
 *
 * Parameters:
 *  In:
 *      u8    - Rate value in SuppRates IE or ExtSuppRates IE
 *  Out:
 *      none
 *
 * Return Value: RateIdx
 *
-*/
u16 RATEwGetRateIdx(u8 byRate)
{
        u16 ii;

        /* erase BasicRate flag */
        byRate = byRate & 0x7F;

        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(struct vnt_private *pDevice,
        PWLAN_IE_SUPP_RATES pItemRates, PWLAN_IE_SUPP_RATES pItemExtRates,
        int bUpdateBasicRate, u16 *pwMaxBasicRate, u16 *pwMaxSuppRate,
        u16 *pwSuppRate, u8 *pbyTopCCKRate, u8 *pbyTopOFDMRate)
{
        int ii;
        u8 byHighSuppRate = 0, byRate = 0;
        u16 wOldBasicRate = pDevice->wBasicRate;
        u32 uRateLen;

        if (pItemRates == NULL)
                return;

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

        DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO"ParseMaxRate Len: %d\n", uRateLen);
        if (pDevice->byBBType != BB_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 = (u8)(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, RATEwGetRateIdx(byRate));
                        DBG_PRT(MSG_LEVEL_DEBUG,
                                KERN_INFO"ParseMaxRate AddBasicRate: %d\n",
                                RATEwGetRateIdx(byRate));
                }
                byRate = (u8)(pItemRates->abyRates[ii]&0x7F);
                if (byHighSuppRate == 0)
                        byHighSuppRate = byRate;
                if (byRate > byHighSuppRate)
                        byHighSuppRate = byRate;
                *pwSuppRate |= (1<<RATEwGetRateIdx(byRate));
        }
        if ((pItemExtRates != NULL) && (pItemExtRates->byElementID == WLAN_EID_EXTSUPP_RATES) &&
                        (pDevice->byBBType != BB_TYPE_11B)) {

                unsigned int uExtRateLen = pItemExtRates->len;

                if (uExtRateLen > WLAN_RATES_MAXLEN)
                        uExtRateLen = WLAN_RATES_MAXLEN;

                for (ii = 0; ii < uExtRateLen; ii++) {
                        byRate = (u8)(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, RATEwGetRateIdx(byRate));
                                DBG_PRT(MSG_LEVEL_DEBUG,
                                                KERN_INFO"ParseMaxRate AddBasicRate: %d\n",
                                                RATEwGetRateIdx(byRate));
                        }
                        byRate = (u8)(pItemExtRates->abyRates[ii]&0x7F);
                        if (byHighSuppRate == 0)
                                byHighSuppRate = byRate;
                        if (byRate > byHighSuppRate)
                                byHighSuppRate = byRate;
                        *pwSuppRate |= (1<<RATEwGetRateIdx(byRate));

                        /* DBG_PRN_GRP09(("ParseMaxRate : HighSuppRate: %d, %X\n",
                         * RATEwGetRateIdx(byRate), byRate));
                         */
                }
        }

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

        *pbyTopCCKRate = pDevice->byTopCCKBasicRate;
        *pbyTopOFDMRate = pDevice->byTopOFDMBasicRate;
        *pwMaxSuppRate = RATEwGetRateIdx(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->byBBType);

        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(struct vnt_private *pDevice,
        PKnownNodeDB psNodeDBTable)
{
        struct vnt_manager *pMgmt = &pDevice->vnt_mgmt;
        u16 wIdxDownRate = 0;
        int ii;
        int bAutoRate[MAX_RATE] = {true, true, true, true, false, false, true,
                                         true, true, true, true, true};
        u32 dwThroughputTbl[MAX_RATE] = {10, 20, 55, 110, 60, 90, 120, 180,
                240, 360, 480, 540};
        u32 dwThroughput = 0;
        u16 wIdxUpRate = 0;
        u32 dwTxDiff = 0;

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

        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 = (u16) 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, (int)psNodeDBTable->uTxOk[ii], (int)psNodeDBTable->uTxFail[ii], (int)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 = (u16) 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(total) == 0 & uTxFail(total) == 0 */
                if (psNodeDBTable->uTxFail[MAX_RATE] == 0)
                        psNodeDBTable->wTxDataRate = wIdxUpRate;
        }

        if (pDevice->byBBType == BB_TYPE_11A) {
                if (psNodeDBTable->wTxDataRate <= RATE_11M)
                        psNodeDBTable->wTxDataRate = RATE_6M;
        }
        DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO"uTxOk[MAX_RATE] %d, uTxFail[MAX_RATE]:%d\n", (int)psNodeDBTable->uTxOk[MAX_RATE], (int)psNodeDBTable->uTxFail[MAX_RATE]);
        s_vResetCounter(psNodeDBTable);
        DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO"Rate: %d, U:%d, D:%d\n", (int)psNodeDBTable->wTxDataRate, (int)wIdxUpRate, (int)wIdxDownRate);
        return;
}

/*+
 *
 * Description:
 *    This routine is used to assemble available Rate IE.
 *
 * Parameters:
 *  In:
 *    pDevice
 *  Out:
 *
 * Return Value: None
 *
-*/
u8 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 (u8)uRateCnt;
}