drivers/mmc/omap3_mmc.c

   1 /*
   2  * (C) Copyright 2008
   3  * Texas Instruments, <www.ti.com>
   4  * Syed Mohammed Khasim <khasim@ti.com>
   5  *
   6  * See file CREDITS for list of people who contributed to this
   7  * project.
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License as
  11  * published by the Free Software Foundation's version 2 of
  12  * the License.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  22  * MA 02111-1307 USA
  23  */
  24
  25 #include <config.h>
  26 #include <common.h>
  27 #include <fat.h>
  28 #include <mmc.h>
  29 #include <part.h>
  30 #include <i2c.h>
  31 #include <twl4030.h>
  32 #include <asm/io.h>
  33
  34 #include "omap3_mmc.h"
  35
  36 static const unsigned short mmc_transspeed_val[15][4] = {
  37         {CLKD(10, 1), CLKD(10, 10), CLKD(10, 100), CLKD(10, 1000)},
  38         {CLKD(12, 1), CLKD(12, 10), CLKD(12, 100), CLKD(12, 1000)},
  39         {CLKD(13, 1), CLKD(13, 10), CLKD(13, 100), CLKD(13, 1000)},
  40         {CLKD(15, 1), CLKD(15, 10), CLKD(15, 100), CLKD(15, 1000)},
  41         {CLKD(20, 1), CLKD(20, 10), CLKD(20, 100), CLKD(20, 1000)},
  42         {CLKD(26, 1), CLKD(26, 10), CLKD(26, 100), CLKD(26, 1000)},
  43         {CLKD(30, 1), CLKD(30, 10), CLKD(30, 100), CLKD(30, 1000)},
  44         {CLKD(35, 1), CLKD(35, 10), CLKD(35, 100), CLKD(35, 1000)},
  45         {CLKD(40, 1), CLKD(40, 10), CLKD(40, 100), CLKD(40, 1000)},
  46         {CLKD(45, 1), CLKD(45, 10), CLKD(45, 100), CLKD(45, 1000)},
  47         {CLKD(52, 1), CLKD(52, 10), CLKD(52, 100), CLKD(52, 1000)},
  48         {CLKD(55, 1), CLKD(55, 10), CLKD(55, 100), CLKD(55, 1000)},
  49         {CLKD(60, 1), CLKD(60, 10), CLKD(60, 100), CLKD(60, 1000)},
  50         {CLKD(70, 1), CLKD(70, 10), CLKD(70, 100), CLKD(70, 1000)},
  51         {CLKD(80, 1), CLKD(80, 10), CLKD(80, 100), CLKD(80, 1000)}
  52 };
  53
  54 static mmc_card_data cur_card_data;
  55 static block_dev_desc_t mmc_blk_dev;
  56 static hsmmc_t *mmc_base = (hsmmc_t *)OMAP_HSMMC1_BASE;
  57
  58 int mmc_set_dev(int dev_num)
  59 {
  60         switch (dev_num) {
  61         case 1:
  62                 mmc_base = (hsmmc_t *)OMAP_HSMMC1_BASE;
  63                 break;
  64         case 2:
  65                 mmc_base = (hsmmc_t *)OMAP_HSMMC2_BASE;
  66                 break;
  67         case 3:
  68                 mmc_base = (hsmmc_t *)OMAP_HSMMC3_BASE;
  69                 break;
  70         default:
  71                 mmc_base = (hsmmc_t *)OMAP_HSMMC1_BASE;
  72                 return 1;
  73         }
  74
  75         return 0;
  76 }
  77
  78 block_dev_desc_t *mmc_get_dev(int dev)
  79 {
  80         return (block_dev_desc_t *) &mmc_blk_dev;
  81 }
  82
  83 static unsigned char mmc_board_init(void)
  84 {
  85 #if defined(CONFIG_TWL4030_POWER)
  86         twl4030_power_mmc_init();
  87 #endif
  88
  89 #if defined(CONFIG_OMAP34XX)
  90         t2_t *t2_base = (t2_t *)T2_BASE;
  91         struct prcm *prcm_base = (struct prcm *)PRCM_BASE;
  92
  93         writel(readl(&t2_base->pbias_lite) | PBIASLITEPWRDNZ1 |
  94                 PBIASSPEEDCTRL0 | PBIASLITEPWRDNZ0,
  95                 &t2_base->pbias_lite);
  96
  97         writel(readl(&t2_base->devconf0) | MMCSDIO1ADPCLKISEL,
  98                 &t2_base->devconf0);
  99
 100         writel(readl(&t2_base->devconf1) | MMCSDIO2ADPCLKISEL,
 101                 &t2_base->devconf1);
 102
 103         writel(readl(&prcm_base->fclken1_core) |
 104                 EN_MMC1 | EN_MMC2 | EN_MMC3,
 105                 &prcm_base->fclken1_core);
 106
 107         writel(readl(&prcm_base->iclken1_core) |
 108                 EN_MMC1 | EN_MMC2 | EN_MMC3,
 109                 &prcm_base->iclken1_core);
 110 #endif
 111
 112 /* TODO add appropriate OMAP4 init */
 113
 114         return 1;
 115 }
 116
 117 static void mmc_init_stream(void)
 118 {
 119         writel(readl(&mmc_base->con) | INIT_INITSTREAM, &mmc_base->con);
 120
 121         writel(MMC_CMD0, &mmc_base->cmd);
 122         while (!(readl(&mmc_base->stat) & CC_MASK));
 123
 124         writel(CC_MASK, &mmc_base->stat);
 125
 126         writel(MMC_CMD0, &mmc_base->cmd);
 127         while (!(readl(&mmc_base->stat) & CC_MASK));
 128
 129         writel(readl(&mmc_base->con) & ~INIT_INITSTREAM, &mmc_base->con);
 130 }
 131
 132 static unsigned char mmc_clock_config(unsigned int iclk, unsigned short clk_div)
 133 {
 134         unsigned int val;
 135
 136         mmc_reg_out(&mmc_base->sysctl, (ICE_MASK | DTO_MASK | CEN_MASK),
 137                         (ICE_STOP | DTO_15THDTO | CEN_DISABLE));
 138
 139         switch (iclk) {
 140         case CLK_INITSEQ:
 141                 val = MMC_INIT_SEQ_CLK / 2;
 142                 break;
 143         case CLK_400KHZ:
 144                 val = MMC_400kHz_CLK;
 145                 break;
 146         case CLK_MISC:
 147                 val = clk_div;
 148                 break;
 149         default:
 150                 return 0;
 151         }
 152         mmc_reg_out(&mmc_base->sysctl, ICE_MASK | CLKD_MASK,
 153                         (val << CLKD_OFFSET) | ICE_OSCILLATE);
 154
 155         while ((readl(&mmc_base->sysctl) & ICS_MASK) == ICS_NOTREADY);
 156
 157         writel(readl(&mmc_base->sysctl) | CEN_ENABLE, &mmc_base->sysctl);
 158         return 1;
 159 }
 160
 161 static unsigned char mmc_init_setup(void)
 162 {
 163         unsigned int reg_val;
 164
 165         mmc_board_init();
 166
 167         writel(readl(&mmc_base->sysconfig) | MMC_SOFTRESET,
 168                 &mmc_base->sysconfig);
 169         while ((readl(&mmc_base->sysstatus) & RESETDONE) == 0);
 170
 171         writel(readl(&mmc_base->sysctl) | SOFTRESETALL, &mmc_base->sysctl);
 172         while ((readl(&mmc_base->sysctl) & SOFTRESETALL) != 0x0);
 173
 174         writel(DTW_1_BITMODE | SDBP_PWROFF | SDVS_3V0, &mmc_base->hctl);
 175         writel(readl(&mmc_base->capa) | VS30_3V0SUP | VS18_1V8SUP,
 176                 &mmc_base->capa);
 177
 178         reg_val = readl(&mmc_base->con) & RESERVED_MASK;
 179
 180         writel(CTPL_MMC_SD | reg_val | WPP_ACTIVEHIGH | CDP_ACTIVEHIGH |
 181                 MIT_CTO | DW8_1_4BITMODE | MODE_FUNC | STR_BLOCK |
 182                 HR_NOHOSTRESP | INIT_NOINIT | NOOPENDRAIN, &mmc_base->con);
 183
 184         mmc_clock_config(CLK_INITSEQ, 0);
 185         writel(readl(&mmc_base->hctl) | SDBP_PWRON, &mmc_base->hctl);
 186
 187         writel(IE_BADA | IE_CERR | IE_DEB | IE_DCRC | IE_DTO | IE_CIE |
 188                 IE_CEB | IE_CCRC | IE_CTO | IE_BRR | IE_BWR | IE_TC | IE_CC,
 189                 &mmc_base->ie);
 190
 191         mmc_init_stream();
 192         return 1;
 193 }
 194
 195 static unsigned char mmc_send_cmd(unsigned int cmd, unsigned int arg,
 196                                 unsigned int *response)
 197 {
 198         unsigned int mmc_stat;
 199
 200         while ((readl(&mmc_base->pstate) & DATI_MASK) == DATI_CMDDIS);
 201
 202         writel(BLEN_512BYTESLEN | NBLK_STPCNT, &mmc_base->blk);
 203         writel(0xFFFFFFFF, &mmc_base->stat);
 204         writel(arg, &mmc_base->arg);
 205         writel(cmd | CMD_TYPE_NORMAL | CICE_NOCHECK | CCCE_NOCHECK |
 206                 MSBS_SGLEBLK | ACEN_DISABLE | BCE_DISABLE | DE_DISABLE,
 207                 &mmc_base->cmd);
 208
 209         while (1) {
 210                 do {
 211                         mmc_stat = readl(&mmc_base->stat);
 212                 } while (mmc_stat == 0);
 213
 214                 if ((mmc_stat & ERRI_MASK) != 0)
 215                         return (unsigned char) mmc_stat;
 216
 217                 if (mmc_stat & CC_MASK) {
 218                         writel(CC_MASK, &mmc_base->stat);
 219                         response[0] = readl(&mmc_base->rsp10);
 220                         if ((cmd & RSP_TYPE_MASK) == RSP_TYPE_LGHT136) {
 221                                 response[1] = readl(&mmc_base->rsp32);
 222                                 response[2] = readl(&mmc_base->rsp54);
 223                                 response[3] = readl(&mmc_base->rsp76);
 224                         }
 225                         break;
 226                 }
 227         }
 228         return 1;
 229 }
 230
 231 static unsigned char mmc_read_data(unsigned int *output_buf)
 232 {
 233         unsigned int mmc_stat;
 234         unsigned int read_count = 0;
 235
 236         /*
 237          * Start Polled Read
 238          */
 239         while (1) {
 240                 do {
 241                         mmc_stat = readl(&mmc_base->stat);
 242                 } while (mmc_stat == 0);
 243
 244                 if ((mmc_stat & ERRI_MASK) != 0)
 245                         return (unsigned char) mmc_stat;
 246
 247                 if (mmc_stat & BRR_MASK) {
 248                         unsigned int k;
 249
 250                         writel(readl(&mmc_base->stat) | BRR_MASK,
 251                                 &mmc_base->stat);
 252                         for (k = 0; k < MMCSD_SECTOR_SIZE / 4; k++) {
 253                                 *output_buf = readl(&mmc_base->data);
 254                                 output_buf++;
 255                                 read_count += 4;
 256                         }
 257                 }
 258
 259                 if (mmc_stat & BWR_MASK)
 260                         writel(readl(&mmc_base->stat) | BWR_MASK,
 261                                 &mmc_base->stat);
 262
 263                 if (mmc_stat & TC_MASK) {
 264                         writel(readl(&mmc_base->stat) | TC_MASK,
 265                                 &mmc_base->stat);
 266                         break;
 267                 }
 268         }
 269         return 1;
 270 }
 271
 272 static unsigned char mmc_detect_card(mmc_card_data *mmc_card_cur)
 273 {
 274         unsigned char err;
 275         unsigned int argument = 0;
 276         unsigned int ocr_value, ocr_recvd, ret_cmd41, hcs_val;
 277         unsigned short retry_cnt = 2000;
 278         mmc_resp_t mmc_resp;
 279
 280         /* Set to Initialization Clock */
 281         err = mmc_clock_config(CLK_400KHZ, 0);
 282         if (err != 1)
 283                 return err;
 284
 285         mmc_card_cur->RCA = MMC_RELATIVE_CARD_ADDRESS;
 286         argument = 0x00000000;
 287
 288         ocr_value = (0x1FF << 15);
 289         err = mmc_send_cmd(MMC_CMD0, argument, mmc_resp.resp);
 290         if (err != 1)
 291                 return err;
 292
 293         argument = SD_CMD8_CHECK_PATTERN | SD_CMD8_2_7_3_6_V_RANGE;
 294         err = mmc_send_cmd(MMC_SDCMD8, argument, mmc_resp.resp);
 295         hcs_val = (err == 1) ?
 296                 MMC_OCR_REG_HOST_CAPACITY_SUPPORT_SECTOR :
 297                 MMC_OCR_REG_HOST_CAPACITY_SUPPORT_BYTE;
 298
 299         argument = 0x0000 << 16;
 300         err = mmc_send_cmd(MMC_CMD55, argument, mmc_resp.resp);
 301         if (err == 1) {
 302                 mmc_card_cur->card_type = SD_CARD;
 303                 ocr_value |= hcs_val;
 304                 ret_cmd41 = MMC_ACMD41;
 305         } else {
 306                 mmc_card_cur->card_type = MMC_CARD;
 307                 ocr_value |= MMC_OCR_REG_ACCESS_MODE_SECTOR;
 308                 ret_cmd41 = MMC_CMD1;
 309                 writel(readl(&mmc_base->con) & ~OD, &mmc_base->con);
 310                 writel(readl(&mmc_base->con) | OPENDRAIN, &mmc_base->con);
 311         }
 312
 313         argument = ocr_value;
 314         err = mmc_send_cmd(ret_cmd41, argument, mmc_resp.resp);
 315         if (err != 1)
 316                 return err;
 317
 318         ocr_recvd = mmc_resp.r3.ocr;
 319
 320         while (!(ocr_recvd & (0x1 << 31)) && (retry_cnt > 0)) {
 321                 retry_cnt--;
 322                 if (mmc_card_cur->card_type == SD_CARD) {
 323                         argument = 0x0000 << 16;
 324                         err = mmc_send_cmd(MMC_CMD55, argument, mmc_resp.resp);
 325                 }
 326
 327                 argument = ocr_value;
 328                 err = mmc_send_cmd(ret_cmd41, argument, mmc_resp.resp);
 329                 if (err != 1)
 330                         return err;
 331                 ocr_recvd = mmc_resp.r3.ocr;
 332         }
 333
 334         if (!(ocr_recvd & (0x1 << 31)))
 335                 return 0;
 336
 337         if (mmc_card_cur->card_type == MMC_CARD) {
 338                 if ((ocr_recvd & MMC_OCR_REG_ACCESS_MODE_MASK) ==
 339                         MMC_OCR_REG_ACCESS_MODE_SECTOR) {
 340                         mmc_card_cur->mode = SECTOR_MODE;
 341                 } else {
 342                         mmc_card_cur->mode = BYTE_MODE;
 343                 }
 344
 345                 ocr_recvd &= ~MMC_OCR_REG_ACCESS_MODE_MASK;
 346         } else {
 347                 if ((ocr_recvd & MMC_OCR_REG_HOST_CAPACITY_SUPPORT_MASK)
 348                         == MMC_OCR_REG_HOST_CAPACITY_SUPPORT_SECTOR) {
 349                         mmc_card_cur->mode = SECTOR_MODE;
 350                 } else {
 351                         mmc_card_cur->mode = BYTE_MODE;
 352                 }
 353                 ocr_recvd &= ~MMC_OCR_REG_HOST_CAPACITY_SUPPORT_MASK;
 354         }
 355
 356         ocr_recvd &= ~(0x1 << 31);
 357         if (!(ocr_recvd & ocr_value))
 358                 return 0;
 359
 360         err = mmc_send_cmd(MMC_CMD2, argument, mmc_resp.resp);
 361         if (err != 1)
 362                 return err;
 363
 364         if (mmc_card_cur->card_type == MMC_CARD) {
 365                 argument = mmc_card_cur->RCA << 16;
 366                 err = mmc_send_cmd(MMC_CMD3, argument, mmc_resp.resp);
 367                 if (err != 1)
 368                         return err;
 369         } else {
 370                 argument = 0x00000000;
 371                 err = mmc_send_cmd(MMC_SDCMD3, argument, mmc_resp.resp);
 372                 if (err != 1)
 373                         return err;
 374
 375                 mmc_card_cur->RCA = mmc_resp.r6.newpublishedrca;
 376         }
 377
 378         writel(readl(&mmc_base->con) & ~OD, &mmc_base->con);
 379         writel(readl(&mmc_base->con) | NOOPENDRAIN, &mmc_base->con);
 380         return 1;
 381 }
 382
 383 static unsigned char mmc_read_cardsize(mmc_card_data *mmc_dev_data,
 384                                 mmc_csd_reg_t *cur_csd)
 385 {
 386         mmc_extended_csd_reg_t ext_csd;
 387         unsigned int size, count, blk_len, blk_no, card_size, argument;
 388         unsigned char err;
 389         unsigned int resp[4];
 390
 391         if (mmc_dev_data->mode == SECTOR_MODE) {
 392                 if (mmc_dev_data->card_type == SD_CARD) {
 393                         card_size =
 394                                 (((mmc_sd2_csd_reg_t *) cur_csd)->
 395                                 c_size_lsb & MMC_SD2_CSD_C_SIZE_LSB_MASK) |
 396                                 ((((mmc_sd2_csd_reg_t *) cur_csd)->
 397                                 c_size_msb & MMC_SD2_CSD_C_SIZE_MSB_MASK)
 398                                 << MMC_SD2_CSD_C_SIZE_MSB_OFFSET);
 399                         mmc_dev_data->size = card_size * 1024;
 400                         if (mmc_dev_data->size == 0)
 401                                 return 0;
 402                 } else {
 403                         argument = 0x00000000;
 404                         err = mmc_send_cmd(MMC_CMD8, argument, resp);
 405                         if (err != 1)
 406                                 return err;
 407                         err = mmc_read_data((unsigned int *) &ext_csd);
 408                         if (err != 1)
 409                                 return err;
 410                         mmc_dev_data->size = ext_csd.sectorcount;
 411
 412                         if (mmc_dev_data->size == 0)
 413                                 mmc_dev_data->size = 8388608;
 414                 }
 415         } else {
 416                 if (cur_csd->c_size_mult >= 8)
 417                         return 0;
 418
 419                 if (cur_csd->read_bl_len >= 12)
 420                         return 0;
 421
 422                 /* Compute size */
 423                 count = 1 << (cur_csd->c_size_mult + 2);
 424                 card_size = (cur_csd->c_size_lsb & MMC_CSD_C_SIZE_LSB_MASK) |
 425                         ((cur_csd->c_size_msb & MMC_CSD_C_SIZE_MSB_MASK)
 426                         << MMC_CSD_C_SIZE_MSB_OFFSET);
 427                 blk_no = (card_size + 1) * count;
 428                 blk_len = 1 << cur_csd->read_bl_len;
 429                 size = blk_no * blk_len;
 430                 mmc_dev_data->size = size / MMCSD_SECTOR_SIZE;
 431                 if (mmc_dev_data->size == 0)
 432                         return 0;
 433         }
 434         return 1;
 435 }
 436
 437 static unsigned long mmc_bread(int dev_num, unsigned long blknr,
 438                 lbaint_t blkcnt, void *dst)
 439 {
 440         unsigned char err;
 441         unsigned int argument;
 442         unsigned int resp[4];
 443         unsigned int *output_buf = dst;
 444         unsigned int sec_inc_val;
 445         lbaint_t i;
 446
 447         if (blkcnt == 0)
 448                 return 0;
 449
 450         if (cur_card_data.mode == SECTOR_MODE) {
 451                 argument = blknr;
 452                 sec_inc_val = 1;
 453         } else {
 454                 argument = blknr * MMCSD_SECTOR_SIZE;
 455                 sec_inc_val = MMCSD_SECTOR_SIZE;
 456         }
 457
 458         for (i = 0; i < blkcnt; i++) {
 459                 err = mmc_send_cmd(MMC_CMD17, argument, resp);
 460                 if (err != 1) {
 461                         printf("mmc: CMD17 failed, status = %08x\n", err);
 462                         break;
 463                 }
 464
 465                 err = mmc_read_data(output_buf);
 466                 if (err != 1) {
 467                         printf("mmc: read failed, status = %08x\n", err);
 468                         break;
 469                 }
 470
 471                 output_buf += (MMCSD_SECTOR_SIZE / 4);
 472                 argument += sec_inc_val;
 473         }
 474
 475         return i;
 476 }
 477
 478 static unsigned char configure_mmc(mmc_card_data *mmc_card_cur)
 479 {
 480         unsigned char ret_val;
 481         unsigned int argument;
 482         unsigned int trans_clk, trans_fact, trans_unit, retries = 2;
 483         unsigned char trans_speed;
 484         mmc_resp_t mmc_resp;
 485
 486         ret_val = mmc_init_setup();
 487
 488         if (ret_val != 1)
 489                 return ret_val;
 490
 491         do {
 492                 ret_val = mmc_detect_card(mmc_card_cur);
 493                 retries--;
 494         } while ((retries > 0) && (ret_val != 1));
 495
 496         argument = mmc_card_cur->RCA << 16;
 497         ret_val = mmc_send_cmd(MMC_CMD9, argument, mmc_resp.resp);
 498         if (ret_val != 1)
 499                 return ret_val;
 500
 501         if (mmc_card_cur->card_type == MMC_CARD)
 502                 mmc_card_cur->version = mmc_resp.Card_CSD.spec_vers;
 503
 504         trans_speed = mmc_resp.Card_CSD.tran_speed;
 505
 506         ret_val = mmc_send_cmd(MMC_CMD4, MMC_DSR_DEFAULT << 16, mmc_resp.resp);
 507         if (ret_val != 1)
 508                 return ret_val;
 509
 510         trans_unit = trans_speed & MMC_CSD_TRAN_SPEED_UNIT_MASK;
 511         trans_fact = trans_speed & MMC_CSD_TRAN_SPEED_FACTOR_MASK;
 512
 513         if (trans_unit > MMC_CSD_TRAN_SPEED_UNIT_100MHZ)
 514                 return 0;
 515
 516         if ((trans_fact < MMC_CSD_TRAN_SPEED_FACTOR_1_0) ||
 517                 (trans_fact > MMC_CSD_TRAN_SPEED_FACTOR_8_0))
 518                 return 0;
 519
 520         trans_unit >>= 0;
 521         trans_fact >>= 3;
 522
 523         trans_clk = mmc_transspeed_val[trans_fact - 1][trans_unit] * 2;
 524         ret_val = mmc_clock_config(CLK_MISC, trans_clk);
 525
 526         if (ret_val != 1)
 527                 return ret_val;
 528
 529         argument = mmc_card_cur->RCA << 16;
 530         ret_val = mmc_send_cmd(MMC_CMD7_SELECT, argument, mmc_resp.resp);
 531         if (ret_val != 1)
 532                 return ret_val;
 533
 534         /* Configure the block length to 512 bytes */
 535         argument = MMCSD_SECTOR_SIZE;
 536         ret_val = mmc_send_cmd(MMC_CMD16, argument, mmc_resp.resp);
 537         if (ret_val != 1)
 538                 return ret_val;
 539
 540         /* get the card size in sectors */
 541         ret_val = mmc_read_cardsize(mmc_card_cur, &mmc_resp.Card_CSD);
 542         if (ret_val != 1)
 543                 return ret_val;
 544
 545         return 1;
 546 }
 547
 548 int mmc_legacy_init(int dev)
 549 {
 550         if (mmc_set_dev(dev) != 0)
 551                 return 1;
 552
 553         if (configure_mmc(&cur_card_data) != 1)
 554                 return 1;
 555
 556         mmc_blk_dev.if_type = IF_TYPE_MMC;
 557         mmc_blk_dev.part_type = PART_TYPE_DOS;
 558         mmc_blk_dev.dev = 0;
 559         mmc_blk_dev.lun = 0;
 560         mmc_blk_dev.type = 0;
 561
 562         /* FIXME fill in the correct size (is set to 32MByte) */
 563         mmc_blk_dev.blksz = MMCSD_SECTOR_SIZE;
 564         mmc_blk_dev.lba = 0x10000;
 565         mmc_blk_dev.removable = 0;
 566         mmc_blk_dev.block_read = mmc_bread;
 567
 568         fat_register_device(&mmc_blk_dev, 1);
 569         return 0;
 570 }