drivers/mmc/host/sdhci-cadence.c

   1 /*
   2  * Copyright (C) 2016 Socionext Inc.
   3  *   Author: Masahiro Yamada <yamada.masahiro@socionext.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  */
  15
  16 #include <linux/bitops.h>
  17 #include <linux/iopoll.h>
  18 #include <linux/module.h>
  19 #include <linux/mmc/host.h>
  20 #include <linux/mmc/mmc.h>
  21 #include <linux/of.h>
  22
  23 #include "sdhci-pltfm.h"
  24
  25 /* HRS - Host Register Set (specific to Cadence) */
  26 #define SDHCI_CDNS_HRS04                0x10            /* PHY access port */
  27 #define   SDHCI_CDNS_HRS04_ACK                  BIT(26)
  28 #define   SDHCI_CDNS_HRS04_RD                   BIT(25)
  29 #define   SDHCI_CDNS_HRS04_WR                   BIT(24)
  30 #define   SDHCI_CDNS_HRS04_RDATA_SHIFT          16
  31 #define   SDHCI_CDNS_HRS04_WDATA_SHIFT          8
  32 #define   SDHCI_CDNS_HRS04_ADDR_SHIFT           0
  33
  34 #define SDHCI_CDNS_HRS06                0x18            /* eMMC control */
  35 #define   SDHCI_CDNS_HRS06_TUNE_UP              BIT(15)
  36 #define   SDHCI_CDNS_HRS06_TUNE_SHIFT           8
  37 #define   SDHCI_CDNS_HRS06_TUNE_MASK            0x3f
  38 #define   SDHCI_CDNS_HRS06_MODE_MASK            0x7
  39 #define   SDHCI_CDNS_HRS06_MODE_SD              0x0
  40 #define   SDHCI_CDNS_HRS06_MODE_MMC_SDR         0x2
  41 #define   SDHCI_CDNS_HRS06_MODE_MMC_DDR         0x3
  42 #define   SDHCI_CDNS_HRS06_MODE_MMC_HS200       0x4
  43 #define   SDHCI_CDNS_HRS06_MODE_MMC_HS400       0x5
  44 #define   SDHCI_CDNS_HRS06_MODE_MMC_HS400ES     0x6
  45
  46 /* SRS - Slot Register Set (SDHCI-compatible) */
  47 #define SDHCI_CDNS_SRS_BASE             0x200
  48
  49 /* PHY */
  50 #define SDHCI_CDNS_PHY_DLY_SD_HS        0x00
  51 #define SDHCI_CDNS_PHY_DLY_SD_DEFAULT   0x01
  52 #define SDHCI_CDNS_PHY_DLY_UHS_SDR12    0x02
  53 #define SDHCI_CDNS_PHY_DLY_UHS_SDR25    0x03
  54 #define SDHCI_CDNS_PHY_DLY_UHS_SDR50    0x04
  55 #define SDHCI_CDNS_PHY_DLY_UHS_DDR50    0x05
  56 #define SDHCI_CDNS_PHY_DLY_EMMC_LEGACY  0x06
  57 #define SDHCI_CDNS_PHY_DLY_EMMC_SDR     0x07
  58 #define SDHCI_CDNS_PHY_DLY_EMMC_DDR     0x08
  59 #define SDHCI_CDNS_PHY_DLY_SDCLK        0x0b
  60 #define SDHCI_CDNS_PHY_DLY_HSMMC        0x0c
  61 #define SDHCI_CDNS_PHY_DLY_STROBE       0x0d
  62
  63 /*
  64  * The tuned val register is 6 bit-wide, but not the whole of the range is
  65  * available.  The range 0-42 seems to be available (then 43 wraps around to 0)
  66  * but I am not quite sure if it is official.  Use only 0 to 39 for safety.
  67  */
  68 #define SDHCI_CDNS_MAX_TUNING_LOOP      40
  69
  70 struct sdhci_cdns_phy_param {
  71         u8 addr;
  72         u8 data;
  73 };
  74
  75 struct sdhci_cdns_priv {
  76         void __iomem *hrs_addr;
  77         bool enhanced_strobe;
  78         unsigned int nr_phy_params;
  79         struct sdhci_cdns_phy_param phy_params[0];
  80 };
  81
  82 struct sdhci_cdns_phy_cfg {
  83         const char *property;
  84         u8 addr;
  85 };
  86
  87 static const struct sdhci_cdns_phy_cfg sdhci_cdns_phy_cfgs[] = {
  88         { "cdns,phy-input-delay-sd-highspeed", SDHCI_CDNS_PHY_DLY_SD_HS, },
  89         { "cdns,phy-input-delay-legacy", SDHCI_CDNS_PHY_DLY_SD_DEFAULT, },
  90         { "cdns,phy-input-delay-sd-uhs-sdr12", SDHCI_CDNS_PHY_DLY_UHS_SDR12, },
  91         { "cdns,phy-input-delay-sd-uhs-sdr25", SDHCI_CDNS_PHY_DLY_UHS_SDR25, },
  92         { "cdns,phy-input-delay-sd-uhs-sdr50", SDHCI_CDNS_PHY_DLY_UHS_SDR50, },
  93         { "cdns,phy-input-delay-sd-uhs-ddr50", SDHCI_CDNS_PHY_DLY_UHS_DDR50, },
  94         { "cdns,phy-input-delay-mmc-highspeed", SDHCI_CDNS_PHY_DLY_EMMC_SDR, },
  95         { "cdns,phy-input-delay-mmc-ddr", SDHCI_CDNS_PHY_DLY_EMMC_DDR, },
  96         { "cdns,phy-dll-delay-sdclk", SDHCI_CDNS_PHY_DLY_SDCLK, },
  97         { "cdns,phy-dll-delay-sdclk-hsmmc", SDHCI_CDNS_PHY_DLY_HSMMC, },
  98         { "cdns,phy-dll-delay-strobe", SDHCI_CDNS_PHY_DLY_STROBE, },
  99 };
 100
 101 static int sdhci_cdns_write_phy_reg(struct sdhci_cdns_priv *priv,
 102                                     u8 addr, u8 data)
 103 {
 104         void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS04;
 105         u32 tmp;
 106         int ret;
 107
 108         tmp = (data << SDHCI_CDNS_HRS04_WDATA_SHIFT) |
 109               (addr << SDHCI_CDNS_HRS04_ADDR_SHIFT);
 110         writel(tmp, reg);
 111
 112         tmp |= SDHCI_CDNS_HRS04_WR;
 113         writel(tmp, reg);
 114
 115         ret = readl_poll_timeout(reg, tmp, tmp & SDHCI_CDNS_HRS04_ACK, 0, 10);
 116         if (ret)
 117                 return ret;
 118
 119         tmp &= ~SDHCI_CDNS_HRS04_WR;
 120         writel(tmp, reg);
 121
 122         return 0;
 123 }
 124
 125 static unsigned int sdhci_cdns_phy_param_count(struct device_node *np)
 126 {
 127         unsigned int count = 0;
 128         int i;
 129
 130         for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++)
 131                 if (of_property_read_bool(np, sdhci_cdns_phy_cfgs[i].property))
 132                         count++;
 133
 134         return count;
 135 }
 136
 137 static void sdhci_cdns_phy_param_parse(struct device_node *np,
 138                                        struct sdhci_cdns_priv *priv)
 139 {
 140         struct sdhci_cdns_phy_param *p = priv->phy_params;
 141         u32 val;
 142         int ret, i;
 143
 144         for (i = 0; i < ARRAY_SIZE(sdhci_cdns_phy_cfgs); i++) {
 145                 ret = of_property_read_u32(np, sdhci_cdns_phy_cfgs[i].property,
 146                                            &val);
 147                 if (ret)
 148                         continue;
 149
 150                 p->addr = sdhci_cdns_phy_cfgs[i].addr;
 151                 p->data = val;
 152                 p++;
 153         }
 154 }
 155
 156 static int sdhci_cdns_phy_init(struct sdhci_cdns_priv *priv)
 157 {
 158         int ret, i;
 159
 160         for (i = 0; i < priv->nr_phy_params; i++) {
 161                 ret = sdhci_cdns_write_phy_reg(priv, priv->phy_params[i].addr,
 162                                                priv->phy_params[i].data);
 163                 if (ret)
 164                         return ret;
 165         }
 166
 167         return 0;
 168 }
 169
 170 static inline void *sdhci_cdns_priv(struct sdhci_host *host)
 171 {
 172         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 173
 174         return sdhci_pltfm_priv(pltfm_host);
 175 }
 176
 177 static unsigned int sdhci_cdns_get_timeout_clock(struct sdhci_host *host)
 178 {
 179         /*
 180          * Cadence's spec says the Timeout Clock Frequency is the same as the
 181          * Base Clock Frequency.
 182          */
 183         return host->max_clk;
 184 }
 185
 186 static void sdhci_cdns_set_emmc_mode(struct sdhci_cdns_priv *priv, u32 mode)
 187 {
 188         u32 tmp;
 189
 190         /* The speed mode for eMMC is selected by HRS06 register */
 191         tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
 192         tmp &= ~SDHCI_CDNS_HRS06_MODE_MASK;
 193         tmp |= mode;
 194         writel(tmp, priv->hrs_addr + SDHCI_CDNS_HRS06);
 195 }
 196
 197 static u32 sdhci_cdns_get_emmc_mode(struct sdhci_cdns_priv *priv)
 198 {
 199         u32 tmp;
 200
 201         tmp = readl(priv->hrs_addr + SDHCI_CDNS_HRS06);
 202         return tmp & SDHCI_CDNS_HRS06_MODE_MASK;
 203 }
 204
 205 static void sdhci_cdns_set_uhs_signaling(struct sdhci_host *host,
 206                                          unsigned int timing)
 207 {
 208         struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
 209         u32 mode;
 210
 211         switch (timing) {
 212         case MMC_TIMING_MMC_HS:
 213                 mode = SDHCI_CDNS_HRS06_MODE_MMC_SDR;
 214                 break;
 215         case MMC_TIMING_MMC_DDR52:
 216                 mode = SDHCI_CDNS_HRS06_MODE_MMC_DDR;
 217                 break;
 218         case MMC_TIMING_MMC_HS200:
 219                 mode = SDHCI_CDNS_HRS06_MODE_MMC_HS200;
 220                 break;
 221         case MMC_TIMING_MMC_HS400:
 222                 if (priv->enhanced_strobe)
 223                         mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400ES;
 224                 else
 225                         mode = SDHCI_CDNS_HRS06_MODE_MMC_HS400;
 226                 break;
 227         default:
 228                 mode = SDHCI_CDNS_HRS06_MODE_SD;
 229                 break;
 230         }
 231
 232         sdhci_cdns_set_emmc_mode(priv, mode);
 233
 234         /* For SD, fall back to the default handler */
 235         if (mode == SDHCI_CDNS_HRS06_MODE_SD)
 236                 sdhci_set_uhs_signaling(host, timing);
 237 }
 238
 239 static const struct sdhci_ops sdhci_cdns_ops = {
 240         .set_clock = sdhci_set_clock,
 241         .get_timeout_clock = sdhci_cdns_get_timeout_clock,
 242         .set_bus_width = sdhci_set_bus_width,
 243         .reset = sdhci_reset,
 244         .set_uhs_signaling = sdhci_cdns_set_uhs_signaling,
 245 };
 246
 247 static const struct sdhci_pltfm_data sdhci_cdns_pltfm_data = {
 248         .ops = &sdhci_cdns_ops,
 249 };
 250
 251 static int sdhci_cdns_set_tune_val(struct sdhci_host *host, unsigned int val)
 252 {
 253         struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
 254         void __iomem *reg = priv->hrs_addr + SDHCI_CDNS_HRS06;
 255         u32 tmp;
 256
 257         if (WARN_ON(val > SDHCI_CDNS_HRS06_TUNE_MASK))
 258                 return -EINVAL;
 259
 260         tmp = readl(reg);
 261         tmp &= ~(SDHCI_CDNS_HRS06_TUNE_MASK << SDHCI_CDNS_HRS06_TUNE_SHIFT);
 262         tmp |= val << SDHCI_CDNS_HRS06_TUNE_SHIFT;
 263         tmp |= SDHCI_CDNS_HRS06_TUNE_UP;
 264         writel(tmp, reg);
 265
 266         return readl_poll_timeout(reg, tmp, !(tmp & SDHCI_CDNS_HRS06_TUNE_UP),
 267                                   0, 1);
 268 }
 269
 270 static int sdhci_cdns_execute_tuning(struct mmc_host *mmc, u32 opcode)
 271 {
 272         struct sdhci_host *host = mmc_priv(mmc);
 273         int cur_streak = 0;
 274         int max_streak = 0;
 275         int end_of_streak = 0;
 276         int i;
 277
 278         /*
 279          * This handler only implements the eMMC tuning that is specific to
 280          * this controller.  Fall back to the standard method for SD timing.
 281          */
 282         if (host->timing != MMC_TIMING_MMC_HS200)
 283                 return sdhci_execute_tuning(mmc, opcode);
 284
 285         if (WARN_ON(opcode != MMC_SEND_TUNING_BLOCK_HS200))
 286                 return -EINVAL;
 287
 288         for (i = 0; i < SDHCI_CDNS_MAX_TUNING_LOOP; i++) {
 289                 if (sdhci_cdns_set_tune_val(host, i) ||
 290                     mmc_send_tuning(host->mmc, opcode, NULL)) { /* bad */
 291                         cur_streak = 0;
 292                 } else { /* good */
 293                         cur_streak++;
 294                         if (cur_streak > max_streak) {
 295                                 max_streak = cur_streak;
 296                                 end_of_streak = i;
 297                         }
 298                 }
 299         }
 300
 301         if (!max_streak) {
 302                 dev_err(mmc_dev(host->mmc), "no tuning point found\n");
 303                 return -EIO;
 304         }
 305
 306         return sdhci_cdns_set_tune_val(host, end_of_streak - max_streak / 2);
 307 }
 308
 309 static void sdhci_cdns_hs400_enhanced_strobe(struct mmc_host *mmc,
 310                                              struct mmc_ios *ios)
 311 {
 312         struct sdhci_host *host = mmc_priv(mmc);
 313         struct sdhci_cdns_priv *priv = sdhci_cdns_priv(host);
 314         u32 mode;
 315
 316         priv->enhanced_strobe = ios->enhanced_strobe;
 317
 318         mode = sdhci_cdns_get_emmc_mode(priv);
 319
 320         if (mode == SDHCI_CDNS_HRS06_MODE_MMC_HS400 && ios->enhanced_strobe)
 321                 sdhci_cdns_set_emmc_mode(priv,
 322                                          SDHCI_CDNS_HRS06_MODE_MMC_HS400ES);
 323
 324         if (mode == SDHCI_CDNS_HRS06_MODE_MMC_HS400ES && !ios->enhanced_strobe)
 325                 sdhci_cdns_set_emmc_mode(priv,
 326                                          SDHCI_CDNS_HRS06_MODE_MMC_HS400);
 327 }
 328
 329 static int sdhci_cdns_probe(struct platform_device *pdev)
 330 {
 331         struct sdhci_host *host;
 332         struct sdhci_pltfm_host *pltfm_host;
 333         struct sdhci_cdns_priv *priv;
 334         struct clk *clk;
 335         size_t priv_size;
 336         unsigned int nr_phy_params;
 337         int ret;
 338         struct device *dev = &pdev->dev;
 339
 340         clk = devm_clk_get(dev, NULL);
 341         if (IS_ERR(clk))
 342                 return PTR_ERR(clk);
 343
 344         ret = clk_prepare_enable(clk);
 345         if (ret)
 346                 return ret;
 347
 348         nr_phy_params = sdhci_cdns_phy_param_count(dev->of_node);
 349         priv_size = sizeof(*priv) + sizeof(priv->phy_params[0]) * nr_phy_params;
 350         host = sdhci_pltfm_init(pdev, &sdhci_cdns_pltfm_data, priv_size);
 351         if (IS_ERR(host)) {
 352                 ret = PTR_ERR(host);
 353                 goto disable_clk;
 354         }
 355
 356         pltfm_host = sdhci_priv(host);
 357         pltfm_host->clk = clk;
 358
 359         priv = sdhci_pltfm_priv(pltfm_host);
 360         priv->nr_phy_params = nr_phy_params;
 361         priv->hrs_addr = host->ioaddr;
 362         priv->enhanced_strobe = false;
 363         host->ioaddr += SDHCI_CDNS_SRS_BASE;
 364         host->mmc_host_ops.execute_tuning = sdhci_cdns_execute_tuning;
 365         host->mmc_host_ops.hs400_enhanced_strobe =
 366                                 sdhci_cdns_hs400_enhanced_strobe;
 367
 368         sdhci_get_of_property(pdev);
 369
 370         ret = mmc_of_parse(host->mmc);
 371         if (ret)
 372                 goto free;
 373
 374         sdhci_cdns_phy_param_parse(dev->of_node, priv);
 375
 376         ret = sdhci_cdns_phy_init(priv);
 377         if (ret)
 378                 goto free;
 379
 380         ret = sdhci_add_host(host);
 381         if (ret)
 382                 goto free;
 383
 384         return 0;
 385 free:
 386         sdhci_pltfm_free(pdev);
 387 disable_clk:
 388         clk_disable_unprepare(clk);
 389
 390         return ret;
 391 }
 392
 393 #ifdef CONFIG_PM_SLEEP
 394 static int sdhci_cdns_resume(struct device *dev)
 395 {
 396         struct sdhci_host *host = dev_get_drvdata(dev);
 397         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 398         struct sdhci_cdns_priv *priv = sdhci_pltfm_priv(pltfm_host);
 399         int ret;
 400
 401         ret = clk_prepare_enable(pltfm_host->clk);
 402         if (ret)
 403                 return ret;
 404
 405         ret = sdhci_cdns_phy_init(priv);
 406         if (ret)
 407                 goto disable_clk;
 408
 409         ret = sdhci_resume_host(host);
 410         if (ret)
 411                 goto disable_clk;
 412
 413         return 0;
 414
 415 disable_clk:
 416         clk_disable_unprepare(pltfm_host->clk);
 417
 418         return ret;
 419 }
 420 #endif
 421
 422 static const struct dev_pm_ops sdhci_cdns_pm_ops = {
 423         SET_SYSTEM_SLEEP_PM_OPS(sdhci_pltfm_suspend, sdhci_cdns_resume)
 424 };
 425
 426 static const struct of_device_id sdhci_cdns_match[] = {
 427         { .compatible = "socionext,uniphier-sd4hc" },
 428         { .compatible = "cdns,sd4hc" },
 429         { /* sentinel */ }
 430 };
 431 MODULE_DEVICE_TABLE(of, sdhci_cdns_match);
 432
 433 static struct platform_driver sdhci_cdns_driver = {
 434         .driver = {
 435                 .name = "sdhci-cdns",
 436                 .pm = &sdhci_cdns_pm_ops,
 437                 .of_match_table = sdhci_cdns_match,
 438         },
 439         .probe = sdhci_cdns_probe,
 440         .remove = sdhci_pltfm_unregister,
 441 };
 442 module_platform_driver(sdhci_cdns_driver);
 443
 444 MODULE_AUTHOR("Masahiro Yamada <yamada.masahiro@socionext.com>");
 445 MODULE_DESCRIPTION("Cadence SD/SDIO/eMMC Host Controller Driver");
 446 MODULE_LICENSE("GPL");