drivers/mmc/host/dw_mmc-exynos.c

   1 /*
   2  * Exynos Specific Extensions for Synopsys DW Multimedia Card Interface driver
   3  *
   4  * Copyright (C) 2012, Samsung Electronics Co., Ltd.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/clk.h>
  15 #include <linux/mmc/host.h>
  16 #include <linux/mmc/dw_mmc.h>
  17 #include <linux/mmc/mmc.h>
  18 #include <linux/of.h>
  19 #include <linux/of_gpio.h>
  20 #include <linux/slab.h>
  21
  22 #include "dw_mmc.h"
  23 #include "dw_mmc-pltfm.h"
  24 #include "dw_mmc-exynos.h"
  25
  26 /* Variations in Exynos specific dw-mshc controller */
  27 enum dw_mci_exynos_type {
  28         DW_MCI_TYPE_EXYNOS4210,
  29         DW_MCI_TYPE_EXYNOS4412,
  30         DW_MCI_TYPE_EXYNOS5250,
  31         DW_MCI_TYPE_EXYNOS5420,
  32         DW_MCI_TYPE_EXYNOS5420_SMU,
  33         DW_MCI_TYPE_EXYNOS7,
  34         DW_MCI_TYPE_EXYNOS7_SMU,
  35 };
  36
  37 /* Exynos implementation specific driver private data */
  38 struct dw_mci_exynos_priv_data {
  39         enum dw_mci_exynos_type         ctrl_type;
  40         u8                              ciu_div;
  41         u32                             sdr_timing;
  42         u32                             ddr_timing;
  43         u32                             hs400_timing;
  44         u32                             tuned_sample;
  45         u32                             cur_speed;
  46         u32                             dqs_delay;
  47         u32                             saved_dqs_en;
  48         u32                             saved_strobe_ctrl;
  49 };
  50
  51 static struct dw_mci_exynos_compatible {
  52         char                            *compatible;
  53         enum dw_mci_exynos_type         ctrl_type;
  54 } exynos_compat[] = {
  55         {
  56                 .compatible     = "samsung,exynos4210-dw-mshc",
  57                 .ctrl_type      = DW_MCI_TYPE_EXYNOS4210,
  58         }, {
  59                 .compatible     = "samsung,exynos4412-dw-mshc",
  60                 .ctrl_type      = DW_MCI_TYPE_EXYNOS4412,
  61         }, {
  62                 .compatible     = "samsung,exynos5250-dw-mshc",
  63                 .ctrl_type      = DW_MCI_TYPE_EXYNOS5250,
  64         }, {
  65                 .compatible     = "samsung,exynos5420-dw-mshc",
  66                 .ctrl_type      = DW_MCI_TYPE_EXYNOS5420,
  67         }, {
  68                 .compatible     = "samsung,exynos5420-dw-mshc-smu",
  69                 .ctrl_type      = DW_MCI_TYPE_EXYNOS5420_SMU,
  70         }, {
  71                 .compatible     = "samsung,exynos7-dw-mshc",
  72                 .ctrl_type      = DW_MCI_TYPE_EXYNOS7,
  73         }, {
  74                 .compatible     = "samsung,exynos7-dw-mshc-smu",
  75                 .ctrl_type      = DW_MCI_TYPE_EXYNOS7_SMU,
  76         },
  77 };
  78
  79 static inline u8 dw_mci_exynos_get_ciu_div(struct dw_mci *host)
  80 {
  81         struct dw_mci_exynos_priv_data *priv = host->priv;
  82
  83         if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
  84                 return EXYNOS4412_FIXED_CIU_CLK_DIV;
  85         else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210)
  86                 return EXYNOS4210_FIXED_CIU_CLK_DIV;
  87         else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
  88                         priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
  89                 return SDMMC_CLKSEL_GET_DIV(mci_readl(host, CLKSEL64)) + 1;
  90         else
  91                 return SDMMC_CLKSEL_GET_DIV(mci_readl(host, CLKSEL)) + 1;
  92 }
  93
  94 static void dw_mci_exynos_config_smu(struct dw_mci *host)
  95 {
  96         struct dw_mci_exynos_priv_data *priv = host->priv;
  97
  98         /*
  99          * If Exynos is provided the Security management,
 100          * set for non-ecryption mode at this time.
 101          */
 102         if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS5420_SMU ||
 103                 priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU) {
 104                 mci_writel(host, MPSBEGIN0, 0);
 105                 mci_writel(host, MPSEND0, SDMMC_ENDING_SEC_NR_MAX);
 106                 mci_writel(host, MPSCTRL0, SDMMC_MPSCTRL_SECURE_WRITE_BIT |
 107                            SDMMC_MPSCTRL_NON_SECURE_READ_BIT |
 108                            SDMMC_MPSCTRL_VALID |
 109                            SDMMC_MPSCTRL_NON_SECURE_WRITE_BIT);
 110         }
 111 }
 112
 113 static int dw_mci_exynos_priv_init(struct dw_mci *host)
 114 {
 115         struct dw_mci_exynos_priv_data *priv = host->priv;
 116
 117         dw_mci_exynos_config_smu(host);
 118
 119         if (priv->ctrl_type >= DW_MCI_TYPE_EXYNOS5420) {
 120                 priv->saved_strobe_ctrl = mci_readl(host, HS400_DLINE_CTRL);
 121                 priv->saved_dqs_en = mci_readl(host, HS400_DQS_EN);
 122                 priv->saved_dqs_en |= AXI_NON_BLOCKING_WR;
 123                 mci_writel(host, HS400_DQS_EN, priv->saved_dqs_en);
 124                 if (!priv->dqs_delay)
 125                         priv->dqs_delay =
 126                                 DQS_CTRL_GET_RD_DELAY(priv->saved_strobe_ctrl);
 127         }
 128
 129         host->bus_hz /= (priv->ciu_div + 1);
 130
 131         return 0;
 132 }
 133
 134 static void dw_mci_exynos_set_clksel_timing(struct dw_mci *host, u32 timing)
 135 {
 136         struct dw_mci_exynos_priv_data *priv = host->priv;
 137         u32 clksel;
 138
 139         if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
 140                 priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
 141                 clksel = mci_readl(host, CLKSEL64);
 142         else
 143                 clksel = mci_readl(host, CLKSEL);
 144
 145         clksel = (clksel & ~SDMMC_CLKSEL_TIMING_MASK) | timing;
 146
 147         if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
 148                 priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
 149                 mci_writel(host, CLKSEL64, clksel);
 150         else
 151                 mci_writel(host, CLKSEL, clksel);
 152
 153         /*
 154          * Exynos4412 and Exynos5250 extends the use of CMD register with the
 155          * use of bit 29 (which is reserved on standard MSHC controllers) for
 156          * optionally bypassing the HOLD register for command and data. The
 157          * HOLD register should be bypassed in case there is no phase shift
 158          * applied on CMD/DATA that is sent to the card.
 159          */
 160         if (!SDMMC_CLKSEL_GET_DRV_WD3(clksel) && host->cur_slot)
 161                 set_bit(DW_MMC_CARD_NO_USE_HOLD, &host->cur_slot->flags);
 162 }
 163
 164 #ifdef CONFIG_PM_SLEEP
 165 static int dw_mci_exynos_suspend(struct device *dev)
 166 {
 167         struct dw_mci *host = dev_get_drvdata(dev);
 168
 169         return dw_mci_suspend(host);
 170 }
 171
 172 static int dw_mci_exynos_resume(struct device *dev)
 173 {
 174         struct dw_mci *host = dev_get_drvdata(dev);
 175
 176         dw_mci_exynos_config_smu(host);
 177         return dw_mci_resume(host);
 178 }
 179
 180 /**
 181  * dw_mci_exynos_resume_noirq - Exynos-specific resume code
 182  *
 183  * On exynos5420 there is a silicon errata that will sometimes leave the
 184  * WAKEUP_INT bit in the CLKSEL register asserted.  This bit is 1 to indicate
 185  * that it fired and we can clear it by writing a 1 back.  Clear it to prevent
 186  * interrupts from going off constantly.
 187  *
 188  * We run this code on all exynos variants because it doesn't hurt.
 189  */
 190
 191 static int dw_mci_exynos_resume_noirq(struct device *dev)
 192 {
 193         struct dw_mci *host = dev_get_drvdata(dev);
 194         struct dw_mci_exynos_priv_data *priv = host->priv;
 195         u32 clksel;
 196
 197         if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
 198                 priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
 199                 clksel = mci_readl(host, CLKSEL64);
 200         else
 201                 clksel = mci_readl(host, CLKSEL);
 202
 203         if (clksel & SDMMC_CLKSEL_WAKEUP_INT) {
 204                 if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
 205                         priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
 206                         mci_writel(host, CLKSEL64, clksel);
 207                 else
 208                         mci_writel(host, CLKSEL, clksel);
 209         }
 210
 211         return 0;
 212 }
 213 #else
 214 #define dw_mci_exynos_suspend           NULL
 215 #define dw_mci_exynos_resume            NULL
 216 #define dw_mci_exynos_resume_noirq      NULL
 217 #endif /* CONFIG_PM_SLEEP */
 218
 219 static void dw_mci_exynos_config_hs400(struct dw_mci *host, u32 timing)
 220 {
 221         struct dw_mci_exynos_priv_data *priv = host->priv;
 222         u32 dqs, strobe;
 223
 224         /*
 225          * Not supported to configure register
 226          * related to HS400
 227          */
 228         if (priv->ctrl_type < DW_MCI_TYPE_EXYNOS5420) {
 229                 if (timing == MMC_TIMING_MMC_HS400)
 230                         dev_warn(host->dev,
 231                                  "cannot configure HS400, unsupported chipset\n");
 232                 return;
 233         }
 234
 235         dqs = priv->saved_dqs_en;
 236         strobe = priv->saved_strobe_ctrl;
 237
 238         if (timing == MMC_TIMING_MMC_HS400) {
 239                 dqs |= DATA_STROBE_EN;
 240                 strobe = DQS_CTRL_RD_DELAY(strobe, priv->dqs_delay);
 241         } else {
 242                 dqs &= ~DATA_STROBE_EN;
 243         }
 244
 245         mci_writel(host, HS400_DQS_EN, dqs);
 246         mci_writel(host, HS400_DLINE_CTRL, strobe);
 247 }
 248
 249 static void dw_mci_exynos_adjust_clock(struct dw_mci *host, unsigned int wanted)
 250 {
 251         struct dw_mci_exynos_priv_data *priv = host->priv;
 252         unsigned long actual;
 253         u8 div;
 254         int ret;
 255         /*
 256          * Don't care if wanted clock is zero or
 257          * ciu clock is unavailable
 258          */
 259         if (!wanted || IS_ERR(host->ciu_clk))
 260                 return;
 261
 262         /* Guaranteed minimum frequency for cclkin */
 263         if (wanted < EXYNOS_CCLKIN_MIN)
 264                 wanted = EXYNOS_CCLKIN_MIN;
 265
 266         if (wanted == priv->cur_speed)
 267                 return;
 268
 269         div = dw_mci_exynos_get_ciu_div(host);
 270         ret = clk_set_rate(host->ciu_clk, wanted * div);
 271         if (ret)
 272                 dev_warn(host->dev,
 273                         "failed to set clk-rate %u error: %d\n",
 274                         wanted * div, ret);
 275         actual = clk_get_rate(host->ciu_clk);
 276         host->bus_hz = actual / div;
 277         priv->cur_speed = wanted;
 278         host->current_speed = 0;
 279 }
 280
 281 static void dw_mci_exynos_set_ios(struct dw_mci *host, struct mmc_ios *ios)
 282 {
 283         struct dw_mci_exynos_priv_data *priv = host->priv;
 284         unsigned int wanted = ios->clock;
 285         u32 timing = ios->timing, clksel;
 286
 287         switch (timing) {
 288         case MMC_TIMING_MMC_HS400:
 289                 /* Update tuned sample timing */
 290                 clksel = SDMMC_CLKSEL_UP_SAMPLE(
 291                                 priv->hs400_timing, priv->tuned_sample);
 292                 wanted <<= 1;
 293                 break;
 294         case MMC_TIMING_MMC_DDR52:
 295                 clksel = priv->ddr_timing;
 296                 /* Should be double rate for DDR mode */
 297                 if (ios->bus_width == MMC_BUS_WIDTH_8)
 298                         wanted <<= 1;
 299                 break;
 300         default:
 301                 clksel = priv->sdr_timing;
 302         }
 303
 304         /* Set clock timing for the requested speed mode*/
 305         dw_mci_exynos_set_clksel_timing(host, clksel);
 306
 307         /* Configure setting for HS400 */
 308         dw_mci_exynos_config_hs400(host, timing);
 309
 310         /* Configure clock rate */
 311         dw_mci_exynos_adjust_clock(host, wanted);
 312 }
 313
 314 static int dw_mci_exynos_parse_dt(struct dw_mci *host)
 315 {
 316         struct dw_mci_exynos_priv_data *priv;
 317         struct device_node *np = host->dev->of_node;
 318         u32 timing[2];
 319         u32 div = 0;
 320         int idx;
 321         int ret;
 322
 323         priv = devm_kzalloc(host->dev, sizeof(*priv), GFP_KERNEL);
 324         if (!priv)
 325                 return -ENOMEM;
 326
 327         for (idx = 0; idx < ARRAY_SIZE(exynos_compat); idx++) {
 328                 if (of_device_is_compatible(np, exynos_compat[idx].compatible))
 329                         priv->ctrl_type = exynos_compat[idx].ctrl_type;
 330         }
 331
 332         if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4412)
 333                 priv->ciu_div = EXYNOS4412_FIXED_CIU_CLK_DIV - 1;
 334         else if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS4210)
 335                 priv->ciu_div = EXYNOS4210_FIXED_CIU_CLK_DIV - 1;
 336         else {
 337                 of_property_read_u32(np, "samsung,dw-mshc-ciu-div", &div);
 338                 priv->ciu_div = div;
 339         }
 340
 341         ret = of_property_read_u32_array(np,
 342                         "samsung,dw-mshc-sdr-timing", timing, 2);
 343         if (ret)
 344                 return ret;
 345
 346         priv->sdr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
 347
 348         ret = of_property_read_u32_array(np,
 349                         "samsung,dw-mshc-ddr-timing", timing, 2);
 350         if (ret)
 351                 return ret;
 352
 353         priv->ddr_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1], div);
 354
 355         ret = of_property_read_u32_array(np,
 356                         "samsung,dw-mshc-hs400-timing", timing, 2);
 357         if (!ret && of_property_read_u32(np,
 358                                 "samsung,read-strobe-delay", &priv->dqs_delay))
 359                 dev_dbg(host->dev,
 360                         "read-strobe-delay is not found, assuming usage of default value\n");
 361
 362         priv->hs400_timing = SDMMC_CLKSEL_TIMING(timing[0], timing[1],
 363                                                 HS400_FIXED_CIU_CLK_DIV);
 364         host->priv = priv;
 365         return 0;
 366 }
 367
 368 static inline u8 dw_mci_exynos_get_clksmpl(struct dw_mci *host)
 369 {
 370         struct dw_mci_exynos_priv_data *priv = host->priv;
 371
 372         if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
 373                 priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
 374                 return SDMMC_CLKSEL_CCLK_SAMPLE(mci_readl(host, CLKSEL64));
 375         else
 376                 return SDMMC_CLKSEL_CCLK_SAMPLE(mci_readl(host, CLKSEL));
 377 }
 378
 379 static inline void dw_mci_exynos_set_clksmpl(struct dw_mci *host, u8 sample)
 380 {
 381         u32 clksel;
 382         struct dw_mci_exynos_priv_data *priv = host->priv;
 383
 384         if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
 385                 priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
 386                 clksel = mci_readl(host, CLKSEL64);
 387         else
 388                 clksel = mci_readl(host, CLKSEL);
 389         clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
 390         if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
 391                 priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
 392                 mci_writel(host, CLKSEL64, clksel);
 393         else
 394                 mci_writel(host, CLKSEL, clksel);
 395 }
 396
 397 static inline u8 dw_mci_exynos_move_next_clksmpl(struct dw_mci *host)
 398 {
 399         struct dw_mci_exynos_priv_data *priv = host->priv;
 400         u32 clksel;
 401         u8 sample;
 402
 403         if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
 404                 priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
 405                 clksel = mci_readl(host, CLKSEL64);
 406         else
 407                 clksel = mci_readl(host, CLKSEL);
 408
 409         sample = (clksel + 1) & 0x7;
 410         clksel = SDMMC_CLKSEL_UP_SAMPLE(clksel, sample);
 411
 412         if (priv->ctrl_type == DW_MCI_TYPE_EXYNOS7 ||
 413                 priv->ctrl_type == DW_MCI_TYPE_EXYNOS7_SMU)
 414                 mci_writel(host, CLKSEL64, clksel);
 415         else
 416                 mci_writel(host, CLKSEL, clksel);
 417
 418         return sample;
 419 }
 420
 421 static s8 dw_mci_exynos_get_best_clksmpl(u8 candiates)
 422 {
 423         const u8 iter = 8;
 424         u8 __c;
 425         s8 i, loc = -1;
 426
 427         for (i = 0; i < iter; i++) {
 428                 __c = ror8(candiates, i);
 429                 if ((__c & 0xc7) == 0xc7) {
 430                         loc = i;
 431                         goto out;
 432                 }
 433         }
 434
 435         for (i = 0; i < iter; i++) {
 436                 __c = ror8(candiates, i);
 437                 if ((__c & 0x83) == 0x83) {
 438                         loc = i;
 439                         goto out;
 440                 }
 441         }
 442
 443 out:
 444         return loc;
 445 }
 446
 447 static int dw_mci_exynos_execute_tuning(struct dw_mci_slot *slot, u32 opcode)
 448 {
 449         struct dw_mci *host = slot->host;
 450         struct dw_mci_exynos_priv_data *priv = host->priv;
 451         struct mmc_host *mmc = slot->mmc;
 452         u8 start_smpl, smpl, candiates = 0;
 453         s8 found = -1;
 454         int ret = 0;
 455
 456         start_smpl = dw_mci_exynos_get_clksmpl(host);
 457
 458         do {
 459                 mci_writel(host, TMOUT, ~0);
 460                 smpl = dw_mci_exynos_move_next_clksmpl(host);
 461
 462                 if (!mmc_send_tuning(mmc, opcode, NULL))
 463                         candiates |= (1 << smpl);
 464
 465         } while (start_smpl != smpl);
 466
 467         found = dw_mci_exynos_get_best_clksmpl(candiates);
 468         if (found >= 0) {
 469                 dw_mci_exynos_set_clksmpl(host, found);
 470                 priv->tuned_sample = found;
 471         } else {
 472                 ret = -EIO;
 473         }
 474
 475         return ret;
 476 }
 477
 478 static int dw_mci_exynos_prepare_hs400_tuning(struct dw_mci *host,
 479                                         struct mmc_ios *ios)
 480 {
 481         struct dw_mci_exynos_priv_data *priv = host->priv;
 482
 483         dw_mci_exynos_set_clksel_timing(host, priv->hs400_timing);
 484         dw_mci_exynos_adjust_clock(host, (ios->clock) << 1);
 485
 486         return 0;
 487 }
 488
 489 /* Common capabilities of Exynos4/Exynos5 SoC */
 490 static unsigned long exynos_dwmmc_caps[4] = {
 491         MMC_CAP_1_8V_DDR | MMC_CAP_8_BIT_DATA | MMC_CAP_CMD23,
 492         MMC_CAP_CMD23,
 493         MMC_CAP_CMD23,
 494         MMC_CAP_CMD23,
 495 };
 496
 497 static const struct dw_mci_drv_data exynos_drv_data = {
 498         .caps                   = exynos_dwmmc_caps,
 499         .init                   = dw_mci_exynos_priv_init,
 500         .set_ios                = dw_mci_exynos_set_ios,
 501         .parse_dt               = dw_mci_exynos_parse_dt,
 502         .execute_tuning         = dw_mci_exynos_execute_tuning,
 503         .prepare_hs400_tuning   = dw_mci_exynos_prepare_hs400_tuning,
 504 };
 505
 506 static const struct of_device_id dw_mci_exynos_match[] = {
 507         { .compatible = "samsung,exynos4412-dw-mshc",
 508                         .data = &exynos_drv_data, },
 509         { .compatible = "samsung,exynos5250-dw-mshc",
 510                         .data = &exynos_drv_data, },
 511         { .compatible = "samsung,exynos5420-dw-mshc",
 512                         .data = &exynos_drv_data, },
 513         { .compatible = "samsung,exynos5420-dw-mshc-smu",
 514                         .data = &exynos_drv_data, },
 515         { .compatible = "samsung,exynos7-dw-mshc",
 516                         .data = &exynos_drv_data, },
 517         { .compatible = "samsung,exynos7-dw-mshc-smu",
 518                         .data = &exynos_drv_data, },
 519         {},
 520 };
 521 MODULE_DEVICE_TABLE(of, dw_mci_exynos_match);
 522
 523 static int dw_mci_exynos_probe(struct platform_device *pdev)
 524 {
 525         const struct dw_mci_drv_data *drv_data;
 526         const struct of_device_id *match;
 527
 528         match = of_match_node(dw_mci_exynos_match, pdev->dev.of_node);
 529         drv_data = match->data;
 530         return dw_mci_pltfm_register(pdev, drv_data);
 531 }
 532
 533 static const struct dev_pm_ops dw_mci_exynos_pmops = {
 534         SET_SYSTEM_SLEEP_PM_OPS(dw_mci_exynos_suspend, dw_mci_exynos_resume)
 535         .resume_noirq = dw_mci_exynos_resume_noirq,
 536         .thaw_noirq = dw_mci_exynos_resume_noirq,
 537         .restore_noirq = dw_mci_exynos_resume_noirq,
 538 };
 539
 540 static struct platform_driver dw_mci_exynos_pltfm_driver = {
 541         .probe          = dw_mci_exynos_probe,
 542         .remove         = dw_mci_pltfm_remove,
 543         .driver         = {
 544                 .name           = "dwmmc_exynos",
 545                 .of_match_table = dw_mci_exynos_match,
 546                 .pm             = &dw_mci_exynos_pmops,
 547         },
 548 };
 549
 550 module_platform_driver(dw_mci_exynos_pltfm_driver);
 551
 552 MODULE_DESCRIPTION("Samsung Specific DW-MSHC Driver Extension");
 553 MODULE_AUTHOR("Thomas Abraham <thomas.ab@samsung.com");
 554 MODULE_LICENSE("GPL v2");
 555 MODULE_ALIAS("platform:dwmmc_exynos");