drivers/net/wireless/mwifiex/cfp.c

   1 /*
   2  * Marvell Wireless LAN device driver: Channel, Frequence and Power
   3  *
   4  * Copyright (C) 2011-2014, Marvell International Ltd.
   5  *
   6  * This software file (the "File") is distributed by Marvell International
   7  * Ltd. under the terms of the GNU General Public License Version 2, June 1991
   8  * (the "License").  You may use, redistribute and/or modify this File in
   9  * accordance with the terms and conditions of the License, a copy of which
  10  * is available by writing to the Free Software Foundation, Inc.,
  11  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA or on the
  12  * worldwide web at http://www.gnu.org/licenses/old-licenses/gpl-2.0.txt.
  13  *
  14  * THE FILE IS DISTRIBUTED AS-IS, WITHOUT WARRANTY OF ANY KIND, AND THE
  15  * IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
  16  * ARE EXPRESSLY DISCLAIMED.  The License provides additional details about
  17  * this warranty disclaimer.
  18  */
  19
  20 #include "decl.h"
  21 #include "ioctl.h"
  22 #include "util.h"
  23 #include "fw.h"
  24 #include "main.h"
  25 #include "cfg80211.h"
  26
  27 /* 100mW */
  28 #define MWIFIEX_TX_PWR_DEFAULT     20
  29 /* 100mW */
  30 #define MWIFIEX_TX_PWR_US_DEFAULT      20
  31 /* 50mW */
  32 #define MWIFIEX_TX_PWR_JP_DEFAULT      16
  33 /* 100mW */
  34 #define MWIFIEX_TX_PWR_FR_100MW        20
  35 /* 10mW */
  36 #define MWIFIEX_TX_PWR_FR_10MW         10
  37 /* 100mW */
  38 #define MWIFIEX_TX_PWR_EMEA_DEFAULT    20
  39
  40 static u8 adhoc_rates_b[B_SUPPORTED_RATES] = { 0x82, 0x84, 0x8b, 0x96, 0 };
  41
  42 static u8 adhoc_rates_g[G_SUPPORTED_RATES] = { 0x8c, 0x12, 0x98, 0x24,
  43                                                0xb0, 0x48, 0x60, 0x6c, 0 };
  44
  45 static u8 adhoc_rates_bg[BG_SUPPORTED_RATES] = { 0x82, 0x84, 0x8b, 0x96,
  46                                                  0x0c, 0x12, 0x18, 0x24,
  47                                                  0x30, 0x48, 0x60, 0x6c, 0 };
  48
  49 static u8 adhoc_rates_a[A_SUPPORTED_RATES] = { 0x8c, 0x12, 0x98, 0x24,
  50                                                0xb0, 0x48, 0x60, 0x6c, 0 };
  51 static u8 supported_rates_a[A_SUPPORTED_RATES] = { 0x0c, 0x12, 0x18, 0x24,
  52                                         0xb0, 0x48, 0x60, 0x6c, 0 };
  53 static u16 mwifiex_data_rates[MWIFIEX_SUPPORTED_RATES_EXT] = { 0x02, 0x04,
  54                                         0x0B, 0x16, 0x00, 0x0C, 0x12, 0x18,
  55                                         0x24, 0x30, 0x48, 0x60, 0x6C, 0x90,
  56                                         0x0D, 0x1A, 0x27, 0x34, 0x4E, 0x68,
  57                                         0x75, 0x82, 0x0C, 0x1B, 0x36, 0x51,
  58                                         0x6C, 0xA2, 0xD8, 0xF3, 0x10E, 0x00 };
  59
  60 static u8 supported_rates_b[B_SUPPORTED_RATES] = { 0x02, 0x04, 0x0b, 0x16, 0 };
  61
  62 static u8 supported_rates_g[G_SUPPORTED_RATES] = { 0x0c, 0x12, 0x18, 0x24,
  63                                         0x30, 0x48, 0x60, 0x6c, 0 };
  64
  65 static u8 supported_rates_bg[BG_SUPPORTED_RATES] = { 0x02, 0x04, 0x0b, 0x0c,
  66                                         0x12, 0x16, 0x18, 0x24, 0x30, 0x48,
  67                                         0x60, 0x6c, 0 };
  68
  69 u16 region_code_index[MWIFIEX_MAX_REGION_CODE] = { 0x10, 0x20, 0x30,
  70                                                 0x32, 0x40, 0x41, 0xff };
  71
  72 static u8 supported_rates_n[N_SUPPORTED_RATES] = { 0x02, 0x04, 0 };
  73
  74 /* For every mcs_rate line, the first 8 bytes are for stream 1x1,
  75  * and all 16 bytes are for stream 2x2.
  76  */
  77 static const u16 mcs_rate[4][16] = {
  78         /* LGI 40M */
  79         { 0x1b, 0x36, 0x51, 0x6c, 0xa2, 0xd8, 0xf3, 0x10e,
  80           0x36, 0x6c, 0xa2, 0xd8, 0x144, 0x1b0, 0x1e6, 0x21c },
  81
  82         /* SGI 40M */
  83         { 0x1e, 0x3c, 0x5a, 0x78, 0xb4, 0xf0, 0x10e, 0x12c,
  84           0x3c, 0x78, 0xb4, 0xf0, 0x168, 0x1e0, 0x21c, 0x258 },
  85
  86         /* LGI 20M */
  87         { 0x0d, 0x1a, 0x27, 0x34, 0x4e, 0x68, 0x75, 0x82,
  88           0x1a, 0x34, 0x4e, 0x68, 0x9c, 0xd0, 0xea, 0x104 },
  89
  90         /* SGI 20M */
  91         { 0x0e, 0x1c, 0x2b, 0x39, 0x56, 0x73, 0x82, 0x90,
  92           0x1c, 0x39, 0x56, 0x73, 0xad, 0xe7, 0x104, 0x120 }
  93 };
  94
  95 /* AC rates */
  96 static const u16 ac_mcs_rate_nss1[8][10] = {
  97         /* LG 160M */
  98         { 0x75, 0xEA, 0x15F, 0x1D4, 0x2BE, 0x3A8, 0x41D,
  99           0x492, 0x57C, 0x618 },
 100
 101         /* SG 160M */
 102         { 0x82, 0x104, 0x186, 0x208, 0x30C, 0x410, 0x492,
 103           0x514, 0x618, 0x6C6 },
 104
 105         /* LG 80M */
 106         { 0x3B, 0x75, 0xB0, 0xEA, 0x15F, 0x1D4, 0x20F,
 107           0x249, 0x2BE, 0x30C },
 108
 109         /* SG 80M */
 110         { 0x41, 0x82, 0xC3, 0x104, 0x186, 0x208, 0x249,
 111           0x28A, 0x30C, 0x363 },
 112
 113         /* LG 40M */
 114         { 0x1B, 0x36, 0x51, 0x6C, 0xA2, 0xD8, 0xF3,
 115           0x10E, 0x144, 0x168 },
 116
 117         /* SG 40M */
 118         { 0x1E, 0x3C, 0x5A, 0x78, 0xB4, 0xF0, 0x10E,
 119           0x12C, 0x168, 0x190 },
 120
 121         /* LG 20M */
 122         { 0xD, 0x1A, 0x27, 0x34, 0x4E, 0x68, 0x75, 0x82, 0x9C, 0x00 },
 123
 124         /* SG 20M */
 125         { 0xF, 0x1D, 0x2C, 0x3A, 0x57, 0x74, 0x82, 0x91, 0xAE, 0x00 },
 126 };
 127
 128 /* NSS2 note: the value in the table is 2 multiplier of the actual rate */
 129 static const u16 ac_mcs_rate_nss2[8][10] = {
 130         /* LG 160M */
 131         { 0xEA, 0x1D4, 0x2BE, 0x3A8, 0x57C, 0x750, 0x83A,
 132           0x924, 0xAF8, 0xC30 },
 133
 134         /* SG 160M */
 135         { 0x104, 0x208, 0x30C, 0x410, 0x618, 0x820, 0x924,
 136           0xA28, 0xC30, 0xD8B },
 137
 138         /* LG 80M */
 139         { 0x75, 0xEA, 0x15F, 0x1D4, 0x2BE, 0x3A8, 0x41D,
 140           0x492, 0x57C, 0x618 },
 141
 142         /* SG 80M */
 143         { 0x82, 0x104, 0x186, 0x208, 0x30C, 0x410, 0x492,
 144           0x514, 0x618, 0x6C6 },
 145
 146         /* LG 40M */
 147         { 0x36, 0x6C, 0xA2, 0xD8, 0x144, 0x1B0, 0x1E6,
 148           0x21C, 0x288, 0x2D0 },
 149
 150         /* SG 40M */
 151         { 0x3C, 0x78, 0xB4, 0xF0, 0x168, 0x1E0, 0x21C,
 152           0x258, 0x2D0, 0x320 },
 153
 154         /* LG 20M */
 155         { 0x1A, 0x34, 0x4A, 0x68, 0x9C, 0xD0, 0xEA, 0x104,
 156           0x138, 0x00 },
 157
 158         /* SG 20M */
 159         { 0x1D, 0x3A, 0x57, 0x74, 0xAE, 0xE6, 0x104, 0x121,
 160           0x15B, 0x00 },
 161 };
 162
 163 struct region_code_mapping {
 164         u8 code;
 165         u8 region[IEEE80211_COUNTRY_STRING_LEN];
 166 };
 167
 168 static struct region_code_mapping region_code_mapping_t[] = {
 169         { 0x10, "US " }, /* US FCC */
 170         { 0x20, "CA " }, /* IC Canada */
 171         { 0x30, "EU " }, /* ETSI */
 172         { 0x31, "ES " }, /* Spain */
 173         { 0x32, "FR " }, /* France */
 174         { 0x40, "JP " }, /* Japan */
 175         { 0x41, "JP " }, /* Japan */
 176         { 0x50, "CN " }, /* China */
 177 };
 178
 179 /* This function converts integer code to region string */
 180 u8 *mwifiex_11d_code_2_region(u8 code)
 181 {
 182         u8 i;
 183         u8 size = sizeof(region_code_mapping_t)/
 184                                 sizeof(struct region_code_mapping);
 185
 186         /* Look for code in mapping table */
 187         for (i = 0; i < size; i++)
 188                 if (region_code_mapping_t[i].code == code)
 189                         return region_code_mapping_t[i].region;
 190
 191         return NULL;
 192 }
 193
 194 /*
 195  * This function maps an index in supported rates table into
 196  * the corresponding data rate.
 197  */
 198 u32 mwifiex_index_to_acs_data_rate(struct mwifiex_private *priv,
 199                                    u8 index, u8 ht_info)
 200 {
 201         u32 rate = 0;
 202         u8 mcs_index = 0;
 203         u8 bw = 0;
 204         u8 gi = 0;
 205
 206         if ((ht_info & 0x3) == MWIFIEX_RATE_FORMAT_VHT) {
 207                 mcs_index = min(index & 0xF, 9);
 208
 209                 /* 20M: bw=0, 40M: bw=1, 80M: bw=2, 160M: bw=3 */
 210                 bw = (ht_info & 0xC) >> 2;
 211
 212                 /* LGI: gi =0, SGI: gi = 1 */
 213                 gi = (ht_info & 0x10) >> 4;
 214
 215                 if ((index >> 4) == 1)  /* NSS = 2 */
 216                         rate = ac_mcs_rate_nss2[2 * (3 - bw) + gi][mcs_index];
 217                 else                    /* NSS = 1 */
 218                         rate = ac_mcs_rate_nss1[2 * (3 - bw) + gi][mcs_index];
 219         } else if ((ht_info & 0x3) == MWIFIEX_RATE_FORMAT_HT) {
 220                 /* 20M: bw=0, 40M: bw=1 */
 221                 bw = (ht_info & 0xC) >> 2;
 222
 223                 /* LGI: gi =0, SGI: gi = 1 */
 224                 gi = (ht_info & 0x10) >> 4;
 225
 226                 if (index == MWIFIEX_RATE_BITMAP_MCS0) {
 227                         if (gi == 1)
 228                                 rate = 0x0D;    /* MCS 32 SGI rate */
 229                         else
 230                                 rate = 0x0C;    /* MCS 32 LGI rate */
 231                 } else if (index < 16) {
 232                         if ((bw == 1) || (bw == 0))
 233                                 rate = mcs_rate[2 * (1 - bw) + gi][index];
 234                         else
 235                                 rate = mwifiex_data_rates[0];
 236                 } else {
 237                         rate = mwifiex_data_rates[0];
 238                 }
 239         } else {
 240                 /* 11n non-HT rates */
 241                 if (index >= MWIFIEX_SUPPORTED_RATES_EXT)
 242                         index = 0;
 243                 rate = mwifiex_data_rates[index];
 244         }
 245
 246         return rate;
 247 }
 248
 249 /* This function maps an index in supported rates table into
 250  * the corresponding data rate.
 251  */
 252 u32 mwifiex_index_to_data_rate(struct mwifiex_private *priv,
 253                                u8 index, u8 ht_info)
 254 {
 255         u32 mcs_num_supp =
 256                 (priv->adapter->user_dev_mcs_support == HT_STREAM_2X2) ? 16 : 8;
 257         u32 rate;
 258
 259         if (priv->adapter->is_hw_11ac_capable)
 260                 return mwifiex_index_to_acs_data_rate(priv, index, ht_info);
 261
 262         if (ht_info & BIT(0)) {
 263                 if (index == MWIFIEX_RATE_BITMAP_MCS0) {
 264                         if (ht_info & BIT(2))
 265                                 rate = 0x0D;    /* MCS 32 SGI rate */
 266                         else
 267                                 rate = 0x0C;    /* MCS 32 LGI rate */
 268                 } else if (index < mcs_num_supp) {
 269                         if (ht_info & BIT(1)) {
 270                                 if (ht_info & BIT(2))
 271                                         /* SGI, 40M */
 272                                         rate = mcs_rate[1][index];
 273                                 else
 274                                         /* LGI, 40M */
 275                                         rate = mcs_rate[0][index];
 276                         } else {
 277                                 if (ht_info & BIT(2))
 278                                         /* SGI, 20M */
 279                                         rate = mcs_rate[3][index];
 280                                 else
 281                                         /* LGI, 20M */
 282                                         rate = mcs_rate[2][index];
 283                         }
 284                 } else
 285                         rate = mwifiex_data_rates[0];
 286         } else {
 287                 if (index >= MWIFIEX_SUPPORTED_RATES_EXT)
 288                         index = 0;
 289                 rate = mwifiex_data_rates[index];
 290         }
 291         return rate;
 292 }
 293
 294 /*
 295  * This function returns the current active data rates.
 296  *
 297  * The result may vary depending upon connection status.
 298  */
 299 u32 mwifiex_get_active_data_rates(struct mwifiex_private *priv, u8 *rates)
 300 {
 301         if (!priv->media_connected)
 302                 return mwifiex_get_supported_rates(priv, rates);
 303         else
 304                 return mwifiex_copy_rates(rates, 0,
 305                                           priv->curr_bss_params.data_rates,
 306                                           priv->curr_bss_params.num_of_rates);
 307 }
 308
 309 /*
 310  * This function locates the Channel-Frequency-Power triplet based upon
 311  * band and channel/frequency parameters.
 312  */
 313 struct mwifiex_chan_freq_power *
 314 mwifiex_get_cfp(struct mwifiex_private *priv, u8 band, u16 channel, u32 freq)
 315 {
 316         struct mwifiex_chan_freq_power *cfp = NULL;
 317         struct ieee80211_supported_band *sband;
 318         struct ieee80211_channel *ch = NULL;
 319         int i;
 320
 321         if (!channel && !freq)
 322                 return cfp;
 323
 324         if (mwifiex_band_to_radio_type(band) == HostCmd_SCAN_RADIO_TYPE_BG)
 325                 sband = priv->wdev.wiphy->bands[IEEE80211_BAND_2GHZ];
 326         else
 327                 sband = priv->wdev.wiphy->bands[IEEE80211_BAND_5GHZ];
 328
 329         if (!sband) {
 330                 mwifiex_dbg(priv->adapter, ERROR,
 331                             "%s: cannot find cfp by band %d\n",
 332                             __func__, band);
 333                 return cfp;
 334         }
 335
 336         for (i = 0; i < sband->n_channels; i++) {
 337                 ch = &sband->channels[i];
 338
 339                 if (ch->flags & IEEE80211_CHAN_DISABLED)
 340                         continue;
 341
 342                 if (freq) {
 343                         if (ch->center_freq == freq)
 344                                 break;
 345                 } else {
 346                         /* find by valid channel*/
 347                         if (ch->hw_value == channel ||
 348                             channel == FIRST_VALID_CHANNEL)
 349                                 break;
 350                 }
 351         }
 352         if (i == sband->n_channels) {
 353                 mwifiex_dbg(priv->adapter, ERROR,
 354                             "%s: cannot find cfp by band %d\t"
 355                             "& channel=%d freq=%d\n",
 356                             __func__, band, channel, freq);
 357         } else {
 358                 if (!ch)
 359                         return cfp;
 360
 361                 priv->cfp.channel = ch->hw_value;
 362                 priv->cfp.freq = ch->center_freq;
 363                 priv->cfp.max_tx_power = ch->max_power;
 364                 cfp = &priv->cfp;
 365         }
 366
 367         return cfp;
 368 }
 369
 370 /*
 371  * This function checks if the data rate is set to auto.
 372  */
 373 u8
 374 mwifiex_is_rate_auto(struct mwifiex_private *priv)
 375 {
 376         u32 i;
 377         int rate_num = 0;
 378
 379         for (i = 0; i < ARRAY_SIZE(priv->bitmap_rates); i++)
 380                 if (priv->bitmap_rates[i])
 381                         rate_num++;
 382
 383         if (rate_num > 1)
 384                 return true;
 385         else
 386                 return false;
 387 }
 388
 389 /* This function gets the supported data rates from bitmask inside
 390  * cfg80211_scan_request.
 391  */
 392 u32 mwifiex_get_rates_from_cfg80211(struct mwifiex_private *priv,
 393                                     u8 *rates, u8 radio_type)
 394 {
 395         struct wiphy *wiphy = priv->adapter->wiphy;
 396         struct cfg80211_scan_request *request = priv->scan_request;
 397         u32 num_rates, rate_mask;
 398         struct ieee80211_supported_band *sband;
 399         int i;
 400
 401         if (radio_type) {
 402                 sband = wiphy->bands[IEEE80211_BAND_5GHZ];
 403                 if (WARN_ON_ONCE(!sband))
 404                         return 0;
 405                 rate_mask = request->rates[IEEE80211_BAND_5GHZ];
 406         } else {
 407                 sband = wiphy->bands[IEEE80211_BAND_2GHZ];
 408                 if (WARN_ON_ONCE(!sband))
 409                         return 0;
 410                 rate_mask = request->rates[IEEE80211_BAND_2GHZ];
 411         }
 412
 413         num_rates = 0;
 414         for (i = 0; i < sband->n_bitrates; i++) {
 415                 if ((BIT(i) & rate_mask) == 0)
 416                         continue; /* skip rate */
 417                 rates[num_rates++] = (u8)(sband->bitrates[i].bitrate / 5);
 418         }
 419
 420         return num_rates;
 421 }
 422
 423 /* This function gets the supported data rates. The function works in
 424  * both Ad-Hoc and infra mode by printing the band and returning the
 425  * data rates.
 426  */
 427 u32 mwifiex_get_supported_rates(struct mwifiex_private *priv, u8 *rates)
 428 {
 429         u32 k = 0;
 430         struct mwifiex_adapter *adapter = priv->adapter;
 431
 432         if (priv->bss_mode == NL80211_IFTYPE_STATION ||
 433             priv->bss_mode == NL80211_IFTYPE_P2P_CLIENT) {
 434                 switch (adapter->config_bands) {
 435                 case BAND_B:
 436                         mwifiex_dbg(adapter, INFO, "info: infra band=%d\t"
 437                                     "supported_rates_b\n",
 438                                     adapter->config_bands);
 439                         k = mwifiex_copy_rates(rates, k, supported_rates_b,
 440                                                sizeof(supported_rates_b));
 441                         break;
 442                 case BAND_G:
 443                 case BAND_G | BAND_GN:
 444                         mwifiex_dbg(adapter, INFO, "info: infra band=%d\t"
 445                                     "supported_rates_g\n",
 446                                     adapter->config_bands);
 447                         k = mwifiex_copy_rates(rates, k, supported_rates_g,
 448                                                sizeof(supported_rates_g));
 449                         break;
 450                 case BAND_B | BAND_G:
 451                 case BAND_A | BAND_B | BAND_G:
 452                 case BAND_A | BAND_B:
 453                 case BAND_A | BAND_B | BAND_G | BAND_GN | BAND_AN:
 454                 case BAND_A | BAND_B | BAND_G | BAND_GN | BAND_AN | BAND_AAC:
 455                 case BAND_B | BAND_G | BAND_GN:
 456                         mwifiex_dbg(adapter, INFO, "info: infra band=%d\t"
 457                                     "supported_rates_bg\n",
 458                                     adapter->config_bands);
 459                         k = mwifiex_copy_rates(rates, k, supported_rates_bg,
 460                                                sizeof(supported_rates_bg));
 461                         break;
 462                 case BAND_A:
 463                 case BAND_A | BAND_G:
 464                         mwifiex_dbg(adapter, INFO, "info: infra band=%d\t"
 465                                     "supported_rates_a\n",
 466                                     adapter->config_bands);
 467                         k = mwifiex_copy_rates(rates, k, supported_rates_a,
 468                                                sizeof(supported_rates_a));
 469                         break;
 470                 case BAND_AN:
 471                 case BAND_A | BAND_AN:
 472                 case BAND_A | BAND_AN | BAND_AAC:
 473                 case BAND_A | BAND_G | BAND_AN | BAND_GN:
 474                 case BAND_A | BAND_G | BAND_AN | BAND_GN | BAND_AAC:
 475                         mwifiex_dbg(adapter, INFO, "info: infra band=%d\t"
 476                                     "supported_rates_a\n",
 477                                     adapter->config_bands);
 478                         k = mwifiex_copy_rates(rates, k, supported_rates_a,
 479                                                sizeof(supported_rates_a));
 480                         break;
 481                 case BAND_GN:
 482                         mwifiex_dbg(adapter, INFO, "info: infra band=%d\t"
 483                                     "supported_rates_n\n",
 484                                     adapter->config_bands);
 485                         k = mwifiex_copy_rates(rates, k, supported_rates_n,
 486                                                sizeof(supported_rates_n));
 487                         break;
 488                 }
 489         } else {
 490                 /* Ad-hoc mode */
 491                 switch (adapter->adhoc_start_band) {
 492                 case BAND_B:
 493                         mwifiex_dbg(adapter, INFO, "info: adhoc B\n");
 494                         k = mwifiex_copy_rates(rates, k, adhoc_rates_b,
 495                                                sizeof(adhoc_rates_b));
 496                         break;
 497                 case BAND_G:
 498                 case BAND_G | BAND_GN:
 499                         mwifiex_dbg(adapter, INFO, "info: adhoc G only\n");
 500                         k = mwifiex_copy_rates(rates, k, adhoc_rates_g,
 501                                                sizeof(adhoc_rates_g));
 502                         break;
 503                 case BAND_B | BAND_G:
 504                 case BAND_B | BAND_G | BAND_GN:
 505                         mwifiex_dbg(adapter, INFO, "info: adhoc BG\n");
 506                         k = mwifiex_copy_rates(rates, k, adhoc_rates_bg,
 507                                                sizeof(adhoc_rates_bg));
 508                         break;
 509                 case BAND_A:
 510                 case BAND_A | BAND_AN:
 511                         mwifiex_dbg(adapter, INFO, "info: adhoc A\n");
 512                         k = mwifiex_copy_rates(rates, k, adhoc_rates_a,
 513                                                sizeof(adhoc_rates_a));
 514                         break;
 515                 }
 516         }
 517
 518         return k;
 519 }
 520
 521 u8 mwifiex_adjust_data_rate(struct mwifiex_private *priv,
 522                             u8 rx_rate, u8 rate_info)
 523 {
 524         u8 rate_index = 0;
 525
 526         /* HT40 */
 527         if ((rate_info & BIT(0)) && (rate_info & BIT(1)))
 528                 rate_index = MWIFIEX_RATE_INDEX_MCS0 +
 529                              MWIFIEX_BW20_MCS_NUM + rx_rate;
 530         else if (rate_info & BIT(0)) /* HT20 */
 531                 rate_index = MWIFIEX_RATE_INDEX_MCS0 + rx_rate;
 532         else
 533                 rate_index = (rx_rate > MWIFIEX_RATE_INDEX_OFDM0) ?
 534                               rx_rate - 1 : rx_rate;
 535
 536         return rate_index;
 537 }