drivers/mmc/host/sdhci-of-at91.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Atmel SDMMC controller driver.
   4  *
   5  * Copyright (C) 2015 Atmel,
   6  *               2015 Ludovic Desroches <ludovic.desroches@atmel.com>
   7  */
   8
   9 #include <linux/bitfield.h>
  10 #include <linux/clk.h>
  11 #include <linux/delay.h>
  12 #include <linux/err.h>
  13 #include <linux/io.h>
  14 #include <linux/kernel.h>
  15 #include <linux/mmc/host.h>
  16 #include <linux/mmc/slot-gpio.h>
  17 #include <linux/module.h>
  18 #include <linux/of.h>
  19 #include <linux/of_device.h>
  20 #include <linux/pm.h>
  21 #include <linux/pm_runtime.h>
  22
  23 #include "sdhci-pltfm.h"
  24
  25 #define SDMMC_MC1R      0x204
  26 #define         SDMMC_MC1R_DDR          BIT(3)
  27 #define         SDMMC_MC1R_FCD          BIT(7)
  28 #define SDMMC_CACR      0x230
  29 #define         SDMMC_CACR_CAPWREN      BIT(0)
  30 #define         SDMMC_CACR_KEY          (0x46 << 8)
  31 #define SDMMC_CALCR     0x240
  32 #define         SDMMC_CALCR_EN          BIT(0)
  33 #define         SDMMC_CALCR_ALWYSON     BIT(4)
  34
  35 #define SDHCI_AT91_PRESET_COMMON_CONF   0x400 /* drv type B, programmable clock mode */
  36
  37 struct sdhci_at91_soc_data {
  38         const struct sdhci_pltfm_data *pdata;
  39         bool baseclk_is_generated_internally;
  40         unsigned int divider_for_baseclk;
  41 };
  42
  43 struct sdhci_at91_priv {
  44         const struct sdhci_at91_soc_data *soc_data;
  45         struct clk *hclock;
  46         struct clk *gck;
  47         struct clk *mainck;
  48         bool restore_needed;
  49         bool cal_always_on;
  50 };
  51
  52 static void sdhci_at91_set_force_card_detect(struct sdhci_host *host)
  53 {
  54         u8 mc1r;
  55
  56         mc1r = readb(host->ioaddr + SDMMC_MC1R);
  57         mc1r |= SDMMC_MC1R_FCD;
  58         writeb(mc1r, host->ioaddr + SDMMC_MC1R);
  59 }
  60
  61 static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock)
  62 {
  63         u16 clk;
  64         unsigned long timeout;
  65
  66         host->mmc->actual_clock = 0;
  67
  68         /*
  69          * There is no requirement to disable the internal clock before
  70          * changing the SD clock configuration. Moreover, disabling the
  71          * internal clock, changing the configuration and re-enabling the
  72          * internal clock causes some bugs. It can prevent to get the internal
  73          * clock stable flag ready and an unexpected switch to the base clock
  74          * when using presets.
  75          */
  76         clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
  77         clk &= SDHCI_CLOCK_INT_EN;
  78         sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
  79
  80         if (clock == 0)
  81                 return;
  82
  83         clk = sdhci_calc_clk(host, clock, &host->mmc->actual_clock);
  84
  85         clk |= SDHCI_CLOCK_INT_EN;
  86         sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
  87
  88         /* Wait max 20 ms */
  89         timeout = 20;
  90         while (!((clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL))
  91                 & SDHCI_CLOCK_INT_STABLE)) {
  92                 if (timeout == 0) {
  93                         pr_err("%s: Internal clock never stabilised.\n",
  94                                mmc_hostname(host->mmc));
  95                         return;
  96                 }
  97                 timeout--;
  98                 mdelay(1);
  99         }
 100
 101         clk |= SDHCI_CLOCK_CARD_EN;
 102         sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
 103 }
 104
 105 static void sdhci_at91_set_uhs_signaling(struct sdhci_host *host,
 106                                          unsigned int timing)
 107 {
 108         if (timing == MMC_TIMING_MMC_DDR52)
 109                 sdhci_writeb(host, SDMMC_MC1R_DDR, SDMMC_MC1R);
 110         sdhci_set_uhs_signaling(host, timing);
 111 }
 112
 113 static void sdhci_at91_reset(struct sdhci_host *host, u8 mask)
 114 {
 115         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 116         struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
 117
 118         sdhci_reset(host, mask);
 119
 120         if ((host->mmc->caps & MMC_CAP_NONREMOVABLE)
 121             || mmc_gpio_get_cd(host->mmc) >= 0)
 122                 sdhci_at91_set_force_card_detect(host);
 123
 124         if (priv->cal_always_on && (mask & SDHCI_RESET_ALL)) {
 125                 u32 calcr = sdhci_readl(host, SDMMC_CALCR);
 126
 127                 sdhci_writel(host, calcr | SDMMC_CALCR_ALWYSON | SDMMC_CALCR_EN,
 128                              SDMMC_CALCR);
 129         }
 130 }
 131
 132 static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
 133         .set_clock              = sdhci_at91_set_clock,
 134         .set_bus_width          = sdhci_set_bus_width,
 135         .reset                  = sdhci_at91_reset,
 136         .set_uhs_signaling      = sdhci_at91_set_uhs_signaling,
 137         .set_power              = sdhci_set_power_and_bus_voltage,
 138 };
 139
 140 static const struct sdhci_pltfm_data sdhci_sama5d2_pdata = {
 141         .ops = &sdhci_at91_sama5d2_ops,
 142 };
 143
 144 static const struct sdhci_at91_soc_data soc_data_sama5d2 = {
 145         .pdata = &sdhci_sama5d2_pdata,
 146         .baseclk_is_generated_internally = false,
 147 };
 148
 149 static const struct sdhci_at91_soc_data soc_data_sam9x60 = {
 150         .pdata = &sdhci_sama5d2_pdata,
 151         .baseclk_is_generated_internally = true,
 152         .divider_for_baseclk = 2,
 153 };
 154
 155 static const struct of_device_id sdhci_at91_dt_match[] = {
 156         { .compatible = "atmel,sama5d2-sdhci", .data = &soc_data_sama5d2 },
 157         { .compatible = "microchip,sam9x60-sdhci", .data = &soc_data_sam9x60 },
 158         {}
 159 };
 160 MODULE_DEVICE_TABLE(of, sdhci_at91_dt_match);
 161
 162 static int sdhci_at91_set_clks_presets(struct device *dev)
 163 {
 164         struct sdhci_host *host = dev_get_drvdata(dev);
 165         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 166         struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
 167         unsigned int                    caps0, caps1;
 168         unsigned int                    clk_base, clk_mul;
 169         unsigned int                    gck_rate, clk_base_rate;
 170         unsigned int                    preset_div;
 171
 172         clk_prepare_enable(priv->hclock);
 173         caps0 = readl(host->ioaddr + SDHCI_CAPABILITIES);
 174         caps1 = readl(host->ioaddr + SDHCI_CAPABILITIES_1);
 175
 176         gck_rate = clk_get_rate(priv->gck);
 177         if (priv->soc_data->baseclk_is_generated_internally)
 178                 clk_base_rate = gck_rate / priv->soc_data->divider_for_baseclk;
 179         else
 180                 clk_base_rate = clk_get_rate(priv->mainck);
 181
 182         clk_base = clk_base_rate / 1000000;
 183         clk_mul = gck_rate / clk_base_rate - 1;
 184
 185         caps0 &= ~SDHCI_CLOCK_V3_BASE_MASK;
 186         caps0 |= FIELD_PREP(SDHCI_CLOCK_V3_BASE_MASK, clk_base);
 187         caps1 &= ~SDHCI_CLOCK_MUL_MASK;
 188         caps1 |= FIELD_PREP(SDHCI_CLOCK_MUL_MASK, clk_mul);
 189         /* Set capabilities in r/w mode. */
 190         writel(SDMMC_CACR_KEY | SDMMC_CACR_CAPWREN, host->ioaddr + SDMMC_CACR);
 191         writel(caps0, host->ioaddr + SDHCI_CAPABILITIES);
 192         writel(caps1, host->ioaddr + SDHCI_CAPABILITIES_1);
 193         /* Set capabilities in ro mode. */
 194         writel(0, host->ioaddr + SDMMC_CACR);
 195
 196         dev_dbg(dev, "update clk mul to %u as gck rate is %u Hz and clk base is %u Hz\n",
 197                 clk_mul, gck_rate, clk_base_rate);
 198
 199         /*
 200          * We have to set preset values because it depends on the clk_mul
 201          * value. Moreover, SDR104 is supported in a degraded mode since the
 202          * maximum sd clock value is 120 MHz instead of 208 MHz. For that
 203          * reason, we need to use presets to support SDR104.
 204          */
 205         preset_div = DIV_ROUND_UP(gck_rate, 24000000) - 1;
 206         writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
 207                host->ioaddr + SDHCI_PRESET_FOR_SDR12);
 208         preset_div = DIV_ROUND_UP(gck_rate, 50000000) - 1;
 209         writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
 210                host->ioaddr + SDHCI_PRESET_FOR_SDR25);
 211         preset_div = DIV_ROUND_UP(gck_rate, 100000000) - 1;
 212         writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
 213                host->ioaddr + SDHCI_PRESET_FOR_SDR50);
 214         preset_div = DIV_ROUND_UP(gck_rate, 120000000) - 1;
 215         writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
 216                host->ioaddr + SDHCI_PRESET_FOR_SDR104);
 217         preset_div = DIV_ROUND_UP(gck_rate, 50000000) - 1;
 218         writew(SDHCI_AT91_PRESET_COMMON_CONF | preset_div,
 219                host->ioaddr + SDHCI_PRESET_FOR_DDR50);
 220
 221         clk_prepare_enable(priv->mainck);
 222         clk_prepare_enable(priv->gck);
 223
 224         return 0;
 225 }
 226
 227 #ifdef CONFIG_PM_SLEEP
 228 static int sdhci_at91_suspend(struct device *dev)
 229 {
 230         struct sdhci_host *host = dev_get_drvdata(dev);
 231         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 232         struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
 233         int ret;
 234
 235         ret = pm_runtime_force_suspend(dev);
 236
 237         priv->restore_needed = true;
 238
 239         return ret;
 240 }
 241 #endif /* CONFIG_PM_SLEEP */
 242
 243 #ifdef CONFIG_PM
 244 static int sdhci_at91_runtime_suspend(struct device *dev)
 245 {
 246         struct sdhci_host *host = dev_get_drvdata(dev);
 247         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 248         struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
 249         int ret;
 250
 251         ret = sdhci_runtime_suspend_host(host);
 252
 253         if (host->tuning_mode != SDHCI_TUNING_MODE_3)
 254                 mmc_retune_needed(host->mmc);
 255
 256         clk_disable_unprepare(priv->gck);
 257         clk_disable_unprepare(priv->hclock);
 258         clk_disable_unprepare(priv->mainck);
 259
 260         return ret;
 261 }
 262
 263 static int sdhci_at91_runtime_resume(struct device *dev)
 264 {
 265         struct sdhci_host *host = dev_get_drvdata(dev);
 266         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 267         struct sdhci_at91_priv *priv = sdhci_pltfm_priv(pltfm_host);
 268         int ret;
 269
 270         if (priv->restore_needed) {
 271                 ret = sdhci_at91_set_clks_presets(dev);
 272                 if (ret)
 273                         return ret;
 274
 275                 priv->restore_needed = false;
 276                 goto out;
 277         }
 278
 279         ret = clk_prepare_enable(priv->mainck);
 280         if (ret) {
 281                 dev_err(dev, "can't enable mainck\n");
 282                 return ret;
 283         }
 284
 285         ret = clk_prepare_enable(priv->hclock);
 286         if (ret) {
 287                 dev_err(dev, "can't enable hclock\n");
 288                 return ret;
 289         }
 290
 291         ret = clk_prepare_enable(priv->gck);
 292         if (ret) {
 293                 dev_err(dev, "can't enable gck\n");
 294                 return ret;
 295         }
 296
 297 out:
 298         return sdhci_runtime_resume_host(host, 0);
 299 }
 300 #endif /* CONFIG_PM */
 301
 302 static const struct dev_pm_ops sdhci_at91_dev_pm_ops = {
 303         SET_SYSTEM_SLEEP_PM_OPS(sdhci_at91_suspend, pm_runtime_force_resume)
 304         SET_RUNTIME_PM_OPS(sdhci_at91_runtime_suspend,
 305                            sdhci_at91_runtime_resume,
 306                            NULL)
 307 };
 308
 309 static int sdhci_at91_probe(struct platform_device *pdev)
 310 {
 311         const struct of_device_id       *match;
 312         const struct sdhci_at91_soc_data        *soc_data;
 313         struct sdhci_host               *host;
 314         struct sdhci_pltfm_host         *pltfm_host;
 315         struct sdhci_at91_priv          *priv;
 316         int                             ret;
 317
 318         match = of_match_device(sdhci_at91_dt_match, &pdev->dev);
 319         if (!match)
 320                 return -EINVAL;
 321         soc_data = match->data;
 322
 323         host = sdhci_pltfm_init(pdev, soc_data->pdata, sizeof(*priv));
 324         if (IS_ERR(host))
 325                 return PTR_ERR(host);
 326
 327         pltfm_host = sdhci_priv(host);
 328         priv = sdhci_pltfm_priv(pltfm_host);
 329         priv->soc_data = soc_data;
 330
 331         priv->mainck = devm_clk_get(&pdev->dev, "baseclk");
 332         if (IS_ERR(priv->mainck)) {
 333                 if (soc_data->baseclk_is_generated_internally) {
 334                         priv->mainck = NULL;
 335                 } else {
 336                         dev_err(&pdev->dev, "failed to get baseclk\n");
 337                         ret = PTR_ERR(priv->mainck);
 338                         goto sdhci_pltfm_free;
 339                 }
 340         }
 341
 342         priv->hclock = devm_clk_get(&pdev->dev, "hclock");
 343         if (IS_ERR(priv->hclock)) {
 344                 dev_err(&pdev->dev, "failed to get hclock\n");
 345                 ret = PTR_ERR(priv->hclock);
 346                 goto sdhci_pltfm_free;
 347         }
 348
 349         priv->gck = devm_clk_get(&pdev->dev, "multclk");
 350         if (IS_ERR(priv->gck)) {
 351                 dev_err(&pdev->dev, "failed to get multclk\n");
 352                 ret = PTR_ERR(priv->gck);
 353                 goto sdhci_pltfm_free;
 354         }
 355
 356         ret = sdhci_at91_set_clks_presets(&pdev->dev);
 357         if (ret)
 358                 goto sdhci_pltfm_free;
 359
 360         priv->restore_needed = false;
 361
 362         /*
 363          * if SDCAL pin is wrongly connected, we must enable
 364          * the analog calibration cell permanently.
 365          */
 366         priv->cal_always_on =
 367                 device_property_read_bool(&pdev->dev,
 368                                           "microchip,sdcal-inverted");
 369
 370         ret = mmc_of_parse(host->mmc);
 371         if (ret)
 372                 goto clocks_disable_unprepare;
 373
 374         sdhci_get_of_property(pdev);
 375
 376         pm_runtime_get_noresume(&pdev->dev);
 377         pm_runtime_set_active(&pdev->dev);
 378         pm_runtime_enable(&pdev->dev);
 379         pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
 380         pm_runtime_use_autosuspend(&pdev->dev);
 381
 382         /* HS200 is broken at this moment */
 383         host->quirks2 |= SDHCI_QUIRK2_BROKEN_HS200;
 384
 385         ret = sdhci_add_host(host);
 386         if (ret)
 387                 goto pm_runtime_disable;
 388
 389         /*
 390          * When calling sdhci_runtime_suspend_host(), the sdhci layer makes
 391          * the assumption that all the clocks of the controller are disabled.
 392          * It means we can't get irq from it when it is runtime suspended.
 393          * For that reason, it is not planned to wake-up on a card detect irq
 394          * from the controller.
 395          * If we want to use runtime PM and to be able to wake-up on card
 396          * insertion, we have to use a GPIO for the card detection or we can
 397          * use polling. Be aware that using polling will resume/suspend the
 398          * controller between each attempt.
 399          * Disable SDHCI_QUIRK_BROKEN_CARD_DETECTION to be sure nobody tries
 400          * to enable polling via device tree with broken-cd property.
 401          */
 402         if (mmc_card_is_removable(host->mmc) &&
 403             mmc_gpio_get_cd(host->mmc) < 0) {
 404                 host->mmc->caps |= MMC_CAP_NEEDS_POLL;
 405                 host->quirks &= ~SDHCI_QUIRK_BROKEN_CARD_DETECTION;
 406         }
 407
 408         /*
 409          * If the device attached to the MMC bus is not removable, it is safer
 410          * to set the Force Card Detect bit. People often don't connect the
 411          * card detect signal and use this pin for another purpose. If the card
 412          * detect pin is not muxed to SDHCI controller, a default value is
 413          * used. This value can be different from a SoC revision to another
 414          * one. Problems come when this default value is not card present. To
 415          * avoid this case, if the device is non removable then the card
 416          * detection procedure using the SDMCC_CD signal is bypassed.
 417          * This bit is reset when a software reset for all command is performed
 418          * so we need to implement our own reset function to set back this bit.
 419          *
 420          * WA: SAMA5D2 doesn't drive CMD if using CD GPIO line.
 421          */
 422         if ((host->mmc->caps & MMC_CAP_NONREMOVABLE)
 423             || mmc_gpio_get_cd(host->mmc) >= 0)
 424                 sdhci_at91_set_force_card_detect(host);
 425
 426         pm_runtime_put_autosuspend(&pdev->dev);
 427
 428         return 0;
 429
 430 pm_runtime_disable:
 431         pm_runtime_disable(&pdev->dev);
 432         pm_runtime_set_suspended(&pdev->dev);
 433         pm_runtime_put_noidle(&pdev->dev);
 434 clocks_disable_unprepare:
 435         clk_disable_unprepare(priv->gck);
 436         clk_disable_unprepare(priv->mainck);
 437         clk_disable_unprepare(priv->hclock);
 438 sdhci_pltfm_free:
 439         sdhci_pltfm_free(pdev);
 440         return ret;
 441 }
 442
 443 static int sdhci_at91_remove(struct platform_device *pdev)
 444 {
 445         struct sdhci_host       *host = platform_get_drvdata(pdev);
 446         struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
 447         struct sdhci_at91_priv  *priv = sdhci_pltfm_priv(pltfm_host);
 448         struct clk *gck = priv->gck;
 449         struct clk *hclock = priv->hclock;
 450         struct clk *mainck = priv->mainck;
 451
 452         pm_runtime_get_sync(&pdev->dev);
 453         pm_runtime_disable(&pdev->dev);
 454         pm_runtime_put_noidle(&pdev->dev);
 455
 456         sdhci_pltfm_unregister(pdev);
 457
 458         clk_disable_unprepare(gck);
 459         clk_disable_unprepare(hclock);
 460         clk_disable_unprepare(mainck);
 461
 462         return 0;
 463 }
 464
 465 static struct platform_driver sdhci_at91_driver = {
 466         .driver         = {
 467                 .name   = "sdhci-at91",
 468                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
 469                 .of_match_table = sdhci_at91_dt_match,
 470                 .pm     = &sdhci_at91_dev_pm_ops,
 471         },
 472         .probe          = sdhci_at91_probe,
 473         .remove         = sdhci_at91_remove,
 474 };
 475
 476 module_platform_driver(sdhci_at91_driver);
 477
 478 MODULE_DESCRIPTION("SDHCI driver for at91");
 479 MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches@atmel.com>");
 480 MODULE_LICENSE("GPL v2");