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
  38 static void mmc_host_classdev_release(struct device *dev)
  39 {
  40         struct mmc_host *host = cls_dev_to_mmc_host(dev);
  41         ida_simple_remove(&mmc_host_ida, host->index);
  42         kfree(host);
  43 }
  44
  45 static struct class mmc_host_class = {
  46         .name           = "mmc_host",
  47         .dev_release    = mmc_host_classdev_release,
  48 };
  49
  50 int mmc_register_host_class(void)
  51 {
  52         return class_register(&mmc_host_class);
  53 }
  54
  55 void mmc_unregister_host_class(void)
  56 {
  57         class_unregister(&mmc_host_class);
  58 }
  59
  60 void mmc_retune_enable(struct mmc_host *host)
  61 {
  62         host->can_retune = 1;
  63         if (host->retune_period)
  64                 mod_timer(&host->retune_timer,
  65                           jiffies + host->retune_period * HZ);
  66 }
  67
  68 /*
  69  * Pause re-tuning for a small set of operations.  The pause begins after the
  70  * next command and after first doing re-tuning.
  71  */
  72 void mmc_retune_pause(struct mmc_host *host)
  73 {
  74         if (!host->retune_paused) {
  75                 host->retune_paused = 1;
  76                 mmc_retune_needed(host);
  77                 mmc_retune_hold(host);
  78         }
  79 }
  80 EXPORT_SYMBOL(mmc_retune_pause);
  81
  82 void mmc_retune_unpause(struct mmc_host *host)
  83 {
  84         if (host->retune_paused) {
  85                 host->retune_paused = 0;
  86                 mmc_retune_release(host);
  87         }
  88 }
  89 EXPORT_SYMBOL(mmc_retune_unpause);
  90
  91 void mmc_retune_disable(struct mmc_host *host)
  92 {
  93         mmc_retune_unpause(host);
  94         host->can_retune = 0;
  95         del_timer_sync(&host->retune_timer);
  96         host->retune_now = 0;
  97         host->need_retune = 0;
  98 }
  99
 100 void mmc_retune_timer_stop(struct mmc_host *host)
 101 {
 102         del_timer_sync(&host->retune_timer);
 103 }
 104 EXPORT_SYMBOL(mmc_retune_timer_stop);
 105
 106 void mmc_retune_hold(struct mmc_host *host)
 107 {
 108         if (!host->hold_retune)
 109                 host->retune_now = 1;
 110         host->hold_retune += 1;
 111 }
 112
 113 void mmc_retune_release(struct mmc_host *host)
 114 {
 115         if (host->hold_retune)
 116                 host->hold_retune -= 1;
 117         else
 118                 WARN_ON(1);
 119 }
 120
 121 int mmc_retune(struct mmc_host *host)
 122 {
 123         bool return_to_hs400 = false;
 124         int err;
 125
 126         if (host->retune_now)
 127                 host->retune_now = 0;
 128         else
 129                 return 0;
 130
 131         if (!host->need_retune || host->doing_retune || !host->card)
 132                 return 0;
 133
 134         host->need_retune = 0;
 135
 136         host->doing_retune = 1;
 137
 138         if (host->ios.timing == MMC_TIMING_MMC_HS400) {
 139                 err = mmc_hs400_to_hs200(host->card);
 140                 if (err)
 141                         goto out;
 142
 143                 return_to_hs400 = true;
 144
 145                 if (host->ops->prepare_hs400_tuning)
 146                         host->ops->prepare_hs400_tuning(host, &host->ios);
 147         }
 148
 149         err = mmc_execute_tuning(host->card);
 150         if (err)
 151                 goto out;
 152
 153         if (return_to_hs400)
 154                 err = mmc_hs200_to_hs400(host->card);
 155 out:
 156         host->doing_retune = 0;
 157
 158         return err;
 159 }
 160
 161 static void mmc_retune_timer(unsigned long data)
 162 {
 163         struct mmc_host *host = (struct mmc_host *)data;
 164
 165         mmc_retune_needed(host);
 166 }
 167
 168 /**
 169  *      mmc_of_parse() - parse host's device-tree node
 170  *      @host: host whose node should be parsed.
 171  *
 172  * To keep the rest of the MMC subsystem unaware of whether DT has been
 173  * used to to instantiate and configure this host instance or not, we
 174  * parse the properties and set respective generic mmc-host flags and
 175  * parameters.
 176  */
 177 int mmc_of_parse(struct mmc_host *host)
 178 {
 179         struct device_node *np;
 180         u32 bus_width;
 181         int ret;
 182         bool cd_cap_invert, cd_gpio_invert = false;
 183         bool ro_cap_invert, ro_gpio_invert = false;
 184
 185         if (!host->parent || !host->parent->of_node)
 186                 return 0;
 187
 188         np = host->parent->of_node;
 189
 190         /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
 191         if (of_property_read_u32(np, "bus-width", &bus_width) < 0) {
 192                 dev_dbg(host->parent,
 193                         "\"bus-width\" property is missing, assuming 1 bit.\n");
 194                 bus_width = 1;
 195         }
 196
 197         switch (bus_width) {
 198         case 8:
 199                 host->caps |= MMC_CAP_8_BIT_DATA;
 200                 /* Hosts capable of 8-bit transfers can also do 4 bits */
 201         case 4:
 202                 host->caps |= MMC_CAP_4_BIT_DATA;
 203                 break;
 204         case 1:
 205                 break;
 206         default:
 207                 dev_err(host->parent,
 208                         "Invalid \"bus-width\" value %u!\n", bus_width);
 209                 return -EINVAL;
 210         }
 211
 212         /* f_max is obtained from the optional "max-frequency" property */
 213         of_property_read_u32(np, "max-frequency", &host->f_max);
 214
 215         /*
 216          * Configure CD and WP pins. They are both by default active low to
 217          * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
 218          * mmc-gpio helpers are used to attach, configure and use them. If
 219          * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
 220          * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
 221          * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
 222          * is set. If the "non-removable" property is found, the
 223          * MMC_CAP_NONREMOVABLE capability is set and no card-detection
 224          * configuration is performed.
 225          */
 226
 227         /* Parse Card Detection */
 228         if (of_property_read_bool(np, "non-removable")) {
 229                 host->caps |= MMC_CAP_NONREMOVABLE;
 230         } else {
 231                 cd_cap_invert = of_property_read_bool(np, "cd-inverted");
 232
 233                 if (of_property_read_bool(np, "broken-cd"))
 234                         host->caps |= MMC_CAP_NEEDS_POLL;
 235
 236                 ret = mmc_gpiod_request_cd(host, "cd", 0, true,
 237                                            0, &cd_gpio_invert);
 238                 if (!ret)
 239                         dev_info(host->parent, "Got CD GPIO\n");
 240                 else if (ret != -ENOENT && ret != -ENOSYS)
 241                         return ret;
 242
 243                 /*
 244                  * There are two ways to flag that the CD line is inverted:
 245                  * through the cd-inverted flag and by the GPIO line itself
 246                  * being inverted from the GPIO subsystem. This is a leftover
 247                  * from the times when the GPIO subsystem did not make it
 248                  * possible to flag a line as inverted.
 249                  *
 250                  * If the capability on the host AND the GPIO line are
 251                  * both inverted, the end result is that the CD line is
 252                  * not inverted.
 253                  */
 254                 if (cd_cap_invert ^ cd_gpio_invert)
 255                         host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
 256         }
 257
 258         /* Parse Write Protection */
 259         ro_cap_invert = of_property_read_bool(np, "wp-inverted");
 260
 261         ret = mmc_gpiod_request_ro(host, "wp", 0, false, 0, &ro_gpio_invert);
 262         if (!ret)
 263                 dev_info(host->parent, "Got WP GPIO\n");
 264         else if (ret != -ENOENT && ret != -ENOSYS)
 265                 return ret;
 266
 267         if (of_property_read_bool(np, "disable-wp"))
 268                 host->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
 269
 270         /* See the comment on CD inversion above */
 271         if (ro_cap_invert ^ ro_gpio_invert)
 272                 host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
 273
 274         if (of_property_read_bool(np, "cap-sd-highspeed"))
 275                 host->caps |= MMC_CAP_SD_HIGHSPEED;
 276         if (of_property_read_bool(np, "cap-mmc-highspeed"))
 277                 host->caps |= MMC_CAP_MMC_HIGHSPEED;
 278         if (of_property_read_bool(np, "sd-uhs-sdr12"))
 279                 host->caps |= MMC_CAP_UHS_SDR12;
 280         if (of_property_read_bool(np, "sd-uhs-sdr25"))
 281                 host->caps |= MMC_CAP_UHS_SDR25;
 282         if (of_property_read_bool(np, "sd-uhs-sdr50"))
 283                 host->caps |= MMC_CAP_UHS_SDR50;
 284         if (of_property_read_bool(np, "sd-uhs-sdr104"))
 285                 host->caps |= MMC_CAP_UHS_SDR104;
 286         if (of_property_read_bool(np, "sd-uhs-ddr50"))
 287                 host->caps |= MMC_CAP_UHS_DDR50;
 288         if (of_property_read_bool(np, "cap-power-off-card"))
 289                 host->caps |= MMC_CAP_POWER_OFF_CARD;
 290         if (of_property_read_bool(np, "cap-mmc-hw-reset"))
 291                 host->caps |= MMC_CAP_HW_RESET;
 292         if (of_property_read_bool(np, "cap-sdio-irq"))
 293                 host->caps |= MMC_CAP_SDIO_IRQ;
 294         if (of_property_read_bool(np, "full-pwr-cycle"))
 295                 host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
 296         if (of_property_read_bool(np, "keep-power-in-suspend"))
 297                 host->pm_caps |= MMC_PM_KEEP_POWER;
 298         if (of_property_read_bool(np, "wakeup-source") ||
 299             of_property_read_bool(np, "enable-sdio-wakeup")) /* legacy */
 300                 host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
 301         if (of_property_read_bool(np, "mmc-ddr-3_3v"))
 302                 host->caps |= MMC_CAP_3_3V_DDR;
 303         if (of_property_read_bool(np, "mmc-ddr-1_8v"))
 304                 host->caps |= MMC_CAP_1_8V_DDR;
 305         if (of_property_read_bool(np, "mmc-ddr-1_2v"))
 306                 host->caps |= MMC_CAP_1_2V_DDR;
 307         if (of_property_read_bool(np, "mmc-hs200-1_8v"))
 308                 host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
 309         if (of_property_read_bool(np, "mmc-hs200-1_2v"))
 310                 host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
 311         if (of_property_read_bool(np, "mmc-hs400-1_8v"))
 312                 host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
 313         if (of_property_read_bool(np, "mmc-hs400-1_2v"))
 314                 host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
 315         if (of_property_read_bool(np, "mmc-hs400-enhanced-strobe"))
 316                 host->caps2 |= MMC_CAP2_HS400_ES;
 317         if (of_property_read_bool(np, "no-sdio"))
 318                 host->caps2 |= MMC_CAP2_NO_SDIO;
 319         if (of_property_read_bool(np, "no-sd"))
 320                 host->caps2 |= MMC_CAP2_NO_SD;
 321         if (of_property_read_bool(np, "no-mmc"))
 322                 host->caps2 |= MMC_CAP2_NO_MMC;
 323
 324         host->dsr_req = !of_property_read_u32(np, "dsr", &host->dsr);
 325         if (host->dsr_req && (host->dsr & ~0xffff)) {
 326                 dev_err(host->parent,
 327                         "device tree specified broken value for DSR: 0x%x, ignoring\n",
 328                         host->dsr);
 329                 host->dsr_req = 0;
 330         }
 331
 332         return mmc_pwrseq_alloc(host);
 333 }
 334
 335 EXPORT_SYMBOL(mmc_of_parse);
 336
 337 /**
 338  *      mmc_alloc_host - initialise the per-host structure.
 339  *      @extra: sizeof private data structure
 340  *      @dev: pointer to host device model structure
 341  *
 342  *      Initialise the per-host structure.
 343  */
 344 struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
 345 {
 346         int err;
 347         struct mmc_host *host;
 348
 349         host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
 350         if (!host)
 351                 return NULL;
 352
 353         /* scanning will be enabled when we're ready */
 354         host->rescan_disable = 1;
 355
 356         err = ida_simple_get(&mmc_host_ida, 0, 0, GFP_KERNEL);
 357         if (err < 0) {
 358                 kfree(host);
 359                 return NULL;
 360         }
 361
 362         host->index = err;
 363
 364         dev_set_name(&host->class_dev, "mmc%d", host->index);
 365
 366         host->parent = dev;
 367         host->class_dev.parent = dev;
 368         host->class_dev.class = &mmc_host_class;
 369         device_initialize(&host->class_dev);
 370         device_enable_async_suspend(&host->class_dev);
 371
 372         if (mmc_gpio_alloc(host)) {
 373                 put_device(&host->class_dev);
 374                 ida_simple_remove(&mmc_host_ida, host->index);
 375                 kfree(host);
 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);