drivers/mmc/core/host.c

   1 /*
   2  *  linux/drivers/mmc/core/host.c
   3  *
   4  *  Copyright (C) 2003 Russell King, All Rights Reserved.
   5  *  Copyright (C) 2007-2008 Pierre Ossman
   6  *  Copyright (C) 2010 Linus Walleij
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  *
  12  *  MMC host class device management
  13  */
  14
  15 #include <linux/device.h>
  16 #include <linux/err.h>
  17 #include <linux/idr.h>
  18 #include <linux/of.h>
  19 #include <linux/of_gpio.h>
  20 #include <linux/pagemap.h>
  21 #include <linux/export.h>
  22 #include <linux/leds.h>
  23 #include <linux/slab.h>
  24
  25 #include <linux/mmc/host.h>
  26 #include <linux/mmc/card.h>
  27 #include <linux/mmc/slot-gpio.h>
  28
  29 #include "core.h"
  30 #include "host.h"
  31 #include "slot-gpio.h"
  32 #include "pwrseq.h"
  33
  34 #define cls_dev_to_mmc_host(d)  container_of(d, struct mmc_host, class_dev)
  35
  36 static DEFINE_IDA(mmc_host_ida);
  37 static DEFINE_SPINLOCK(mmc_host_lock);
  38
  39 static void mmc_host_classdev_release(struct device *dev)
  40 {
  41         struct mmc_host *host = cls_dev_to_mmc_host(dev);
  42         spin_lock(&mmc_host_lock);
  43         ida_remove(&mmc_host_ida, host->index);
  44         spin_unlock(&mmc_host_lock);
  45         kfree(host);
  46 }
  47
  48 static struct class mmc_host_class = {
  49         .name           = "mmc_host",
  50         .dev_release    = mmc_host_classdev_release,
  51 };
  52
  53 int mmc_register_host_class(void)
  54 {
  55         return class_register(&mmc_host_class);
  56 }
  57
  58 void mmc_unregister_host_class(void)
  59 {
  60         class_unregister(&mmc_host_class);
  61 }
  62
  63 void mmc_retune_enable(struct mmc_host *host)
  64 {
  65         host->can_retune = 1;
  66         if (host->retune_period)
  67                 mod_timer(&host->retune_timer,
  68                           jiffies + host->retune_period * HZ);
  69 }
  70
  71 /*
  72  * Pause re-tuning for a small set of operations.  The pause begins after the
  73  * next command and after first doing re-tuning.
  74  */
  75 void mmc_retune_pause(struct mmc_host *host)
  76 {
  77         if (!host->retune_paused) {
  78                 host->retune_paused = 1;
  79                 mmc_retune_needed(host);
  80                 mmc_retune_hold(host);
  81         }
  82 }
  83 EXPORT_SYMBOL(mmc_retune_pause);
  84
  85 void mmc_retune_unpause(struct mmc_host *host)
  86 {
  87         if (host->retune_paused) {
  88                 host->retune_paused = 0;
  89                 mmc_retune_release(host);
  90         }
  91 }
  92 EXPORT_SYMBOL(mmc_retune_unpause);
  93
  94 void mmc_retune_disable(struct mmc_host *host)
  95 {
  96         mmc_retune_unpause(host);
  97         host->can_retune = 0;
  98         del_timer_sync(&host->retune_timer);
  99         host->retune_now = 0;
 100         host->need_retune = 0;
 101 }
 102
 103 void mmc_retune_timer_stop(struct mmc_host *host)
 104 {
 105         del_timer_sync(&host->retune_timer);
 106 }
 107 EXPORT_SYMBOL(mmc_retune_timer_stop);
 108
 109 void mmc_retune_hold(struct mmc_host *host)
 110 {
 111         if (!host->hold_retune)
 112                 host->retune_now = 1;
 113         host->hold_retune += 1;
 114 }
 115
 116 void mmc_retune_release(struct mmc_host *host)
 117 {
 118         if (host->hold_retune)
 119                 host->hold_retune -= 1;
 120         else
 121                 WARN_ON(1);
 122 }
 123
 124 int mmc_retune(struct mmc_host *host)
 125 {
 126         bool return_to_hs400 = false;
 127         int err;
 128
 129         if (host->retune_now)
 130                 host->retune_now = 0;
 131         else
 132                 return 0;
 133
 134         if (!host->need_retune || host->doing_retune || !host->card)
 135                 return 0;
 136
 137         host->need_retune = 0;
 138
 139         host->doing_retune = 1;
 140
 141         if (host->ios.timing == MMC_TIMING_MMC_HS400) {
 142                 err = mmc_hs400_to_hs200(host->card);
 143                 if (err)
 144                         goto out;
 145
 146                 return_to_hs400 = true;
 147
 148                 if (host->ops->prepare_hs400_tuning)
 149                         host->ops->prepare_hs400_tuning(host, &host->ios);
 150         }
 151
 152         err = mmc_execute_tuning(host->card);
 153         if (err)
 154                 goto out;
 155
 156         if (return_to_hs400)
 157                 err = mmc_hs200_to_hs400(host->card);
 158 out:
 159         host->doing_retune = 0;
 160
 161         return err;
 162 }
 163
 164 static void mmc_retune_timer(unsigned long data)
 165 {
 166         struct mmc_host *host = (struct mmc_host *)data;
 167
 168         mmc_retune_needed(host);
 169 }
 170
 171 /**
 172  *      mmc_of_parse() - parse host's device-tree node
 173  *      @host: host whose node should be parsed.
 174  *
 175  * To keep the rest of the MMC subsystem unaware of whether DT has been
 176  * used to to instantiate and configure this host instance or not, we
 177  * parse the properties and set respective generic mmc-host flags and
 178  * parameters.
 179  */
 180 int mmc_of_parse(struct mmc_host *host)
 181 {
 182         struct device_node *np;
 183         u32 bus_width;
 184         int ret;
 185         bool cd_cap_invert, cd_gpio_invert = false;
 186         bool ro_cap_invert, ro_gpio_invert = false;
 187
 188         if (!host->parent || !host->parent->of_node)
 189                 return 0;
 190
 191         np = host->parent->of_node;
 192
 193         /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
 194         if (of_property_read_u32(np, "bus-width", &bus_width) < 0) {
 195                 dev_dbg(host->parent,
 196                         "\"bus-width\" property is missing, assuming 1 bit.\n");
 197                 bus_width = 1;
 198         }
 199
 200         switch (bus_width) {
 201         case 8:
 202                 host->caps |= MMC_CAP_8_BIT_DATA;
 203                 /* Hosts capable of 8-bit transfers can also do 4 bits */
 204         case 4:
 205                 host->caps |= MMC_CAP_4_BIT_DATA;
 206                 break;
 207         case 1:
 208                 break;
 209         default:
 210                 dev_err(host->parent,
 211                         "Invalid \"bus-width\" value %u!\n", bus_width);
 212                 return -EINVAL;
 213         }
 214
 215         /* f_max is obtained from the optional "max-frequency" property */
 216         of_property_read_u32(np, "max-frequency", &host->f_max);
 217
 218         /*
 219          * Configure CD and WP pins. They are both by default active low to
 220          * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
 221          * mmc-gpio helpers are used to attach, configure and use them. If
 222          * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
 223          * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
 224          * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
 225          * is set. If the "non-removable" property is found, the
 226          * MMC_CAP_NONREMOVABLE capability is set and no card-detection
 227          * configuration is performed.
 228          */
 229
 230         /* Parse Card Detection */
 231         if (of_property_read_bool(np, "non-removable")) {
 232                 host->caps |= MMC_CAP_NONREMOVABLE;
 233         } else {
 234                 cd_cap_invert = of_property_read_bool(np, "cd-inverted");
 235
 236                 if (of_property_read_bool(np, "broken-cd"))
 237                         host->caps |= MMC_CAP_NEEDS_POLL;
 238
 239                 ret = mmc_gpiod_request_cd(host, "cd", 0, true,
 240                                            0, &cd_gpio_invert);
 241                 if (!ret)
 242                         dev_info(host->parent, "Got CD GPIO\n");
 243                 else if (ret != -ENOENT && ret != -ENOSYS)
 244                         return ret;
 245
 246                 /*
 247                  * There are two ways to flag that the CD line is inverted:
 248                  * through the cd-inverted flag and by the GPIO line itself
 249                  * being inverted from the GPIO subsystem. This is a leftover
 250                  * from the times when the GPIO subsystem did not make it
 251                  * possible to flag a line as inverted.
 252                  *
 253                  * If the capability on the host AND the GPIO line are
 254                  * both inverted, the end result is that the CD line is
 255                  * not inverted.
 256                  */
 257                 if (cd_cap_invert ^ cd_gpio_invert)
 258                         host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
 259         }
 260
 261         /* Parse Write Protection */
 262         ro_cap_invert = of_property_read_bool(np, "wp-inverted");
 263
 264         ret = mmc_gpiod_request_ro(host, "wp", 0, false, 0, &ro_gpio_invert);
 265         if (!ret)
 266                 dev_info(host->parent, "Got WP GPIO\n");
 267         else if (ret != -ENOENT && ret != -ENOSYS)
 268                 return ret;
 269
 270         if (of_property_read_bool(np, "disable-wp"))
 271                 host->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
 272
 273         /* See the comment on CD inversion above */
 274         if (ro_cap_invert ^ ro_gpio_invert)
 275                 host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
 276
 277         if (of_property_read_bool(np, "cap-sd-highspeed"))
 278                 host->caps |= MMC_CAP_SD_HIGHSPEED;
 279         if (of_property_read_bool(np, "cap-mmc-highspeed"))
 280                 host->caps |= MMC_CAP_MMC_HIGHSPEED;
 281         if (of_property_read_bool(np, "sd-uhs-sdr12"))
 282                 host->caps |= MMC_CAP_UHS_SDR12;
 283         if (of_property_read_bool(np, "sd-uhs-sdr25"))
 284                 host->caps |= MMC_CAP_UHS_SDR25;
 285         if (of_property_read_bool(np, "sd-uhs-sdr50"))
 286                 host->caps |= MMC_CAP_UHS_SDR50;
 287         if (of_property_read_bool(np, "sd-uhs-sdr104"))
 288                 host->caps |= MMC_CAP_UHS_SDR104;
 289         if (of_property_read_bool(np, "sd-uhs-ddr50"))
 290                 host->caps |= MMC_CAP_UHS_DDR50;
 291         if (of_property_read_bool(np, "cap-power-off-card"))
 292                 host->caps |= MMC_CAP_POWER_OFF_CARD;
 293         if (of_property_read_bool(np, "cap-mmc-hw-reset"))
 294                 host->caps |= MMC_CAP_HW_RESET;
 295         if (of_property_read_bool(np, "cap-sdio-irq"))
 296                 host->caps |= MMC_CAP_SDIO_IRQ;
 297         if (of_property_read_bool(np, "full-pwr-cycle"))
 298                 host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
 299         if (of_property_read_bool(np, "keep-power-in-suspend"))
 300                 host->pm_caps |= MMC_PM_KEEP_POWER;
 301         if (of_property_read_bool(np, "wakeup-source") ||
 302             of_property_read_bool(np, "enable-sdio-wakeup")) /* legacy */
 303                 host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
 304         if (of_property_read_bool(np, "mmc-ddr-1_8v"))
 305                 host->caps |= MMC_CAP_1_8V_DDR;
 306         if (of_property_read_bool(np, "mmc-ddr-1_2v"))
 307                 host->caps |= MMC_CAP_1_2V_DDR;
 308         if (of_property_read_bool(np, "mmc-hs200-1_8v"))
 309                 host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
 310         if (of_property_read_bool(np, "mmc-hs200-1_2v"))
 311                 host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
 312         if (of_property_read_bool(np, "mmc-hs400-1_8v"))
 313                 host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
 314         if (of_property_read_bool(np, "mmc-hs400-1_2v"))
 315                 host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
 316
 317         host->dsr_req = !of_property_read_u32(np, "dsr", &host->dsr);
 318         if (host->dsr_req && (host->dsr & ~0xffff)) {
 319                 dev_err(host->parent,
 320                         "device tree specified broken value for DSR: 0x%x, ignoring\n",
 321                         host->dsr);
 322                 host->dsr_req = 0;
 323         }
 324
 325         return mmc_pwrseq_alloc(host);
 326 }
 327
 328 EXPORT_SYMBOL(mmc_of_parse);
 329
 330 /**
 331  *      mmc_alloc_host - initialise the per-host structure.
 332  *      @extra: sizeof private data structure
 333  *      @dev: pointer to host device model structure
 334  *
 335  *      Initialise the per-host structure.
 336  */
 337 struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
 338 {
 339         int err;
 340         struct mmc_host *host;
 341
 342         host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
 343         if (!host)
 344                 return NULL;
 345
 346         /* scanning will be enabled when we're ready */
 347         host->rescan_disable = 1;
 348
 349 again:
 350         if (!ida_pre_get(&mmc_host_ida, GFP_KERNEL)) {
 351                 kfree(host);
 352                 return NULL;
 353         }
 354
 355         spin_lock(&mmc_host_lock);
 356         err = ida_get_new(&mmc_host_ida, &host->index);
 357         spin_unlock(&mmc_host_lock);
 358
 359         if (err == -EAGAIN) {
 360                 goto again;
 361         } else if (err) {
 362                 kfree(host);
 363                 return NULL;
 364         }
 365
 366         dev_set_name(&host->class_dev, "mmc%d", host->index);
 367
 368         host->parent = dev;
 369         host->class_dev.parent = dev;
 370         host->class_dev.class = &mmc_host_class;
 371         device_initialize(&host->class_dev);
 372         device_enable_async_suspend(&host->class_dev);
 373
 374         if (mmc_gpio_alloc(host)) {
 375                 put_device(&host->class_dev);
 376                 return NULL;
 377         }
 378
 379         spin_lock_init(&host->lock);
 380         init_waitqueue_head(&host->wq);
 381         INIT_DELAYED_WORK(&host->detect, mmc_rescan);
 382         setup_timer(&host->retune_timer, mmc_retune_timer, (unsigned long)host);
 383
 384         /*
 385          * By default, hosts do not support SGIO or large requests.
 386          * They have to set these according to their abilities.
 387          */
 388         host->max_segs = 1;
 389         host->max_seg_size = PAGE_SIZE;
 390
 391         host->max_req_size = PAGE_SIZE;
 392         host->max_blk_size = 512;
 393         host->max_blk_count = PAGE_SIZE / 512;
 394
 395         return host;
 396 }
 397
 398 EXPORT_SYMBOL(mmc_alloc_host);
 399
 400 /**
 401  *      mmc_add_host - initialise host hardware
 402  *      @host: mmc host
 403  *
 404  *      Register the host with the driver model. The host must be
 405  *      prepared to start servicing requests before this function
 406  *      completes.
 407  */
 408 int mmc_add_host(struct mmc_host *host)
 409 {
 410         int err;
 411
 412         WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
 413                 !host->ops->enable_sdio_irq);
 414
 415         err = device_add(&host->class_dev);
 416         if (err)
 417                 return err;
 418
 419         led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
 420
 421 #ifdef CONFIG_DEBUG_FS
 422         mmc_add_host_debugfs(host);
 423 #endif
 424
 425         mmc_start_host(host);
 426         mmc_register_pm_notifier(host);
 427
 428         return 0;
 429 }
 430
 431 EXPORT_SYMBOL(mmc_add_host);
 432
 433 /**
 434  *      mmc_remove_host - remove host hardware
 435  *      @host: mmc host
 436  *
 437  *      Unregister and remove all cards associated with this host,
 438  *      and power down the MMC bus. No new requests will be issued
 439  *      after this function has returned.
 440  */
 441 void mmc_remove_host(struct mmc_host *host)
 442 {
 443         mmc_unregister_pm_notifier(host);
 444         mmc_stop_host(host);
 445
 446 #ifdef CONFIG_DEBUG_FS
 447         mmc_remove_host_debugfs(host);
 448 #endif
 449
 450         device_del(&host->class_dev);
 451
 452         led_trigger_unregister_simple(host->led);
 453 }
 454
 455 EXPORT_SYMBOL(mmc_remove_host);
 456
 457 /**
 458  *      mmc_free_host - free the host structure
 459  *      @host: mmc host
 460  *
 461  *      Free the host once all references to it have been dropped.
 462  */
 463 void mmc_free_host(struct mmc_host *host)
 464 {
 465         mmc_pwrseq_free(host);
 466         put_device(&host->class_dev);
 467 }
 468
 469 EXPORT_SYMBOL(mmc_free_host);