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 #include "sdio_ops.h"
  34
  35 #define cls_dev_to_mmc_host(d)  container_of(d, struct mmc_host, class_dev)
  36
  37 static DEFINE_IDA(mmc_host_ida);
  38
  39 static void mmc_host_classdev_release(struct device *dev)
  40 {
  41         struct mmc_host *host = cls_dev_to_mmc_host(dev);
  42         ida_simple_remove(&mmc_host_ida, host->index);
  43         kfree(host);
  44 }
  45
  46 static struct class mmc_host_class = {
  47         .name           = "mmc_host",
  48         .dev_release    = mmc_host_classdev_release,
  49 };
  50
  51 int mmc_register_host_class(void)
  52 {
  53         return class_register(&mmc_host_class);
  54 }
  55
  56 void mmc_unregister_host_class(void)
  57 {
  58         class_unregister(&mmc_host_class);
  59 }
  60
  61 void mmc_retune_enable(struct mmc_host *host)
  62 {
  63         host->can_retune = 1;
  64         if (host->retune_period)
  65                 mod_timer(&host->retune_timer,
  66                           jiffies + host->retune_period * HZ);
  67 }
  68
  69 /*
  70  * Pause re-tuning for a small set of operations.  The pause begins after the
  71  * next command and after first doing re-tuning.
  72  */
  73 void mmc_retune_pause(struct mmc_host *host)
  74 {
  75         if (!host->retune_paused) {
  76                 host->retune_paused = 1;
  77                 mmc_retune_needed(host);
  78                 mmc_retune_hold(host);
  79         }
  80 }
  81 EXPORT_SYMBOL(mmc_retune_pause);
  82
  83 void mmc_retune_unpause(struct mmc_host *host)
  84 {
  85         if (host->retune_paused) {
  86                 host->retune_paused = 0;
  87                 mmc_retune_release(host);
  88         }
  89 }
  90 EXPORT_SYMBOL(mmc_retune_unpause);
  91
  92 void mmc_retune_disable(struct mmc_host *host)
  93 {
  94         mmc_retune_unpause(host);
  95         host->can_retune = 0;
  96         del_timer_sync(&host->retune_timer);
  97         host->retune_now = 0;
  98         host->need_retune = 0;
  99 }
 100
 101 void mmc_retune_timer_stop(struct mmc_host *host)
 102 {
 103         del_timer_sync(&host->retune_timer);
 104 }
 105 EXPORT_SYMBOL(mmc_retune_timer_stop);
 106
 107 void mmc_retune_hold(struct mmc_host *host)
 108 {
 109         if (!host->hold_retune)
 110                 host->retune_now = 1;
 111         host->hold_retune += 1;
 112 }
 113
 114 void mmc_retune_release(struct mmc_host *host)
 115 {
 116         if (host->hold_retune)
 117                 host->hold_retune -= 1;
 118         else
 119                 WARN_ON(1);
 120 }
 121 EXPORT_SYMBOL(mmc_retune_release);
 122
 123 int mmc_retune(struct mmc_host *host)
 124 {
 125         bool return_to_hs400 = false;
 126         int err;
 127
 128         if (host->retune_now)
 129                 host->retune_now = 0;
 130         else
 131                 return 0;
 132
 133         if (!host->need_retune || host->doing_retune || !host->card)
 134                 return 0;
 135
 136         host->need_retune = 0;
 137
 138         host->doing_retune = 1;
 139
 140         if (host->ios.timing == MMC_TIMING_MMC_HS400) {
 141                 err = mmc_hs400_to_hs200(host->card);
 142                 if (err)
 143                         goto out;
 144
 145                 return_to_hs400 = true;
 146         }
 147
 148         err = mmc_execute_tuning(host->card);
 149         if (err)
 150                 goto out;
 151
 152         if (return_to_hs400)
 153                 err = mmc_hs200_to_hs400(host->card);
 154 out:
 155         host->doing_retune = 0;
 156
 157         return err;
 158 }
 159
 160 static void mmc_retune_timer(struct timer_list *t)
 161 {
 162         struct mmc_host *host = from_timer(host, t, retune_timer);
 163
 164         mmc_retune_needed(host);
 165 }
 166
 167 /**
 168  *      mmc_of_parse() - parse host's device-tree node
 169  *      @host: host whose node should be parsed.
 170  *
 171  * To keep the rest of the MMC subsystem unaware of whether DT has been
 172  * used to to instantiate and configure this host instance or not, we
 173  * parse the properties and set respective generic mmc-host flags and
 174  * parameters.
 175  */
 176 int mmc_of_parse(struct mmc_host *host)
 177 {
 178         struct device *dev = host->parent;
 179         u32 bus_width, drv_type, cd_debounce_delay_ms;
 180         int ret;
 181         bool cd_cap_invert, cd_gpio_invert = false;
 182         bool ro_cap_invert, ro_gpio_invert = false;
 183
 184         if (!dev || !dev_fwnode(dev))
 185                 return 0;
 186
 187         /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
 188         if (device_property_read_u32(dev, "bus-width", &bus_width) < 0) {
 189                 dev_dbg(host->parent,
 190                         "\"bus-width\" property is missing, assuming 1 bit.\n");
 191                 bus_width = 1;
 192         }
 193
 194         switch (bus_width) {
 195         case 8:
 196                 host->caps |= MMC_CAP_8_BIT_DATA;
 197                 /* Hosts capable of 8-bit transfers can also do 4 bits */
 198         case 4:
 199                 host->caps |= MMC_CAP_4_BIT_DATA;
 200                 break;
 201         case 1:
 202                 break;
 203         default:
 204                 dev_err(host->parent,
 205                         "Invalid \"bus-width\" value %u!\n", bus_width);
 206                 return -EINVAL;
 207         }
 208
 209         /* f_max is obtained from the optional "max-frequency" property */
 210         device_property_read_u32(dev, "max-frequency", &host->f_max);
 211
 212         /*
 213          * Configure CD and WP pins. They are both by default active low to
 214          * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
 215          * mmc-gpio helpers are used to attach, configure and use them. If
 216          * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
 217          * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
 218          * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
 219          * is set. If the "non-removable" property is found, the
 220          * MMC_CAP_NONREMOVABLE capability is set and no card-detection
 221          * configuration is performed.
 222          */
 223
 224         /* Parse Card Detection */
 225         if (device_property_read_bool(dev, "non-removable")) {
 226                 host->caps |= MMC_CAP_NONREMOVABLE;
 227         } else {
 228                 cd_cap_invert = device_property_read_bool(dev, "cd-inverted");
 229
 230                 if (device_property_read_u32(dev, "cd-debounce-delay-ms",
 231                                              &cd_debounce_delay_ms))
 232                         cd_debounce_delay_ms = 200;
 233
 234                 if (device_property_read_bool(dev, "broken-cd"))
 235                         host->caps |= MMC_CAP_NEEDS_POLL;
 236
 237                 ret = mmc_gpiod_request_cd(host, "cd", 0, false,
 238                                            cd_debounce_delay_ms * 1000,
 239                                            &cd_gpio_invert);
 240                 if (!ret)
 241                         dev_info(host->parent, "Got CD GPIO\n");
 242                 else if (ret != -ENOENT && ret != -ENOSYS)
 243                         return ret;
 244
 245                 /*
 246                  * There are two ways to flag that the CD line is inverted:
 247                  * through the cd-inverted flag and by the GPIO line itself
 248                  * being inverted from the GPIO subsystem. This is a leftover
 249                  * from the times when the GPIO subsystem did not make it
 250                  * possible to flag a line as inverted.
 251                  *
 252                  * If the capability on the host AND the GPIO line are
 253                  * both inverted, the end result is that the CD line is
 254                  * not inverted.
 255                  */
 256                 if (cd_cap_invert ^ cd_gpio_invert)
 257                         host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
 258         }
 259
 260         /* Parse Write Protection */
 261         ro_cap_invert = device_property_read_bool(dev, "wp-inverted");
 262
 263         ret = mmc_gpiod_request_ro(host, "wp", 0, false, 0, &ro_gpio_invert);
 264         if (!ret)
 265                 dev_info(host->parent, "Got WP GPIO\n");
 266         else if (ret != -ENOENT && ret != -ENOSYS)
 267                 return ret;
 268
 269         if (device_property_read_bool(dev, "disable-wp"))
 270                 host->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
 271
 272         /* See the comment on CD inversion above */
 273         if (ro_cap_invert ^ ro_gpio_invert)
 274                 host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
 275
 276         if (device_property_read_bool(dev, "cap-sd-highspeed"))
 277                 host->caps |= MMC_CAP_SD_HIGHSPEED;
 278         if (device_property_read_bool(dev, "cap-mmc-highspeed"))
 279                 host->caps |= MMC_CAP_MMC_HIGHSPEED;
 280         if (device_property_read_bool(dev, "sd-uhs-sdr12"))
 281                 host->caps |= MMC_CAP_UHS_SDR12;
 282         if (device_property_read_bool(dev, "sd-uhs-sdr25"))
 283                 host->caps |= MMC_CAP_UHS_SDR25;
 284         if (device_property_read_bool(dev, "sd-uhs-sdr50"))
 285                 host->caps |= MMC_CAP_UHS_SDR50;
 286         if (device_property_read_bool(dev, "sd-uhs-sdr104"))
 287                 host->caps |= MMC_CAP_UHS_SDR104;
 288         if (device_property_read_bool(dev, "sd-uhs-ddr50"))
 289                 host->caps |= MMC_CAP_UHS_DDR50;
 290         if (device_property_read_bool(dev, "cap-power-off-card"))
 291                 host->caps |= MMC_CAP_POWER_OFF_CARD;
 292         if (device_property_read_bool(dev, "cap-mmc-hw-reset"))
 293                 host->caps |= MMC_CAP_HW_RESET;
 294         if (device_property_read_bool(dev, "cap-sdio-irq"))
 295                 host->caps |= MMC_CAP_SDIO_IRQ;
 296         if (device_property_read_bool(dev, "full-pwr-cycle"))
 297                 host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
 298         if (device_property_read_bool(dev, "keep-power-in-suspend"))
 299                 host->pm_caps |= MMC_PM_KEEP_POWER;
 300         if (device_property_read_bool(dev, "wakeup-source") ||
 301             device_property_read_bool(dev, "enable-sdio-wakeup")) /* legacy */
 302                 host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
 303         if (device_property_read_bool(dev, "mmc-ddr-3_3v"))
 304                 host->caps |= MMC_CAP_3_3V_DDR;
 305         if (device_property_read_bool(dev, "mmc-ddr-1_8v"))
 306                 host->caps |= MMC_CAP_1_8V_DDR;
 307         if (device_property_read_bool(dev, "mmc-ddr-1_2v"))
 308                 host->caps |= MMC_CAP_1_2V_DDR;
 309         if (device_property_read_bool(dev, "mmc-hs200-1_8v"))
 310                 host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
 311         if (device_property_read_bool(dev, "mmc-hs200-1_2v"))
 312                 host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
 313         if (device_property_read_bool(dev, "mmc-hs400-1_8v"))
 314                 host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
 315         if (device_property_read_bool(dev, "mmc-hs400-1_2v"))
 316                 host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
 317         if (device_property_read_bool(dev, "mmc-hs400-enhanced-strobe"))
 318                 host->caps2 |= MMC_CAP2_HS400_ES;
 319         if (device_property_read_bool(dev, "no-sdio"))
 320                 host->caps2 |= MMC_CAP2_NO_SDIO;
 321         if (device_property_read_bool(dev, "no-sd"))
 322                 host->caps2 |= MMC_CAP2_NO_SD;
 323         if (device_property_read_bool(dev, "no-mmc"))
 324                 host->caps2 |= MMC_CAP2_NO_MMC;
 325
 326         /* Must be after "non-removable" check */
 327         if (device_property_read_u32(dev, "fixed-emmc-driver-type", &drv_type) == 0) {
 328                 if (host->caps & MMC_CAP_NONREMOVABLE)
 329                         host->fixed_drv_type = drv_type;
 330                 else
 331                         dev_err(host->parent,
 332                                 "can't use fixed driver type, media is removable\n");
 333         }
 334
 335         host->dsr_req = !device_property_read_u32(dev, "dsr", &host->dsr);
 336         if (host->dsr_req && (host->dsr & ~0xffff)) {
 337                 dev_err(host->parent,
 338                         "device tree specified broken value for DSR: 0x%x, ignoring\n",
 339                         host->dsr);
 340                 host->dsr_req = 0;
 341         }
 342
 343         device_property_read_u32(dev, "post-power-on-delay-ms",
 344                                  &host->ios.power_delay_ms);
 345
 346         return mmc_pwrseq_alloc(host);
 347 }
 348
 349 EXPORT_SYMBOL(mmc_of_parse);
 350
 351 /**
 352  *      mmc_alloc_host - initialise the per-host structure.
 353  *      @extra: sizeof private data structure
 354  *      @dev: pointer to host device model structure
 355  *
 356  *      Initialise the per-host structure.
 357  */
 358 struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
 359 {
 360         int err;
 361         struct mmc_host *host;
 362
 363         host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
 364         if (!host)
 365                 return NULL;
 366
 367         /* scanning will be enabled when we're ready */
 368         host->rescan_disable = 1;
 369
 370         err = ida_simple_get(&mmc_host_ida, 0, 0, GFP_KERNEL);
 371         if (err < 0) {
 372                 kfree(host);
 373                 return NULL;
 374         }
 375
 376         host->index = err;
 377
 378         dev_set_name(&host->class_dev, "mmc%d", host->index);
 379
 380         host->parent = dev;
 381         host->class_dev.parent = dev;
 382         host->class_dev.class = &mmc_host_class;
 383         device_initialize(&host->class_dev);
 384         device_enable_async_suspend(&host->class_dev);
 385
 386         if (mmc_gpio_alloc(host)) {
 387                 put_device(&host->class_dev);
 388                 ida_simple_remove(&mmc_host_ida, host->index);
 389                 kfree(host);
 390                 return NULL;
 391         }
 392
 393         spin_lock_init(&host->lock);
 394         init_waitqueue_head(&host->wq);
 395         INIT_DELAYED_WORK(&host->detect, mmc_rescan);
 396         INIT_DELAYED_WORK(&host->sdio_irq_work, sdio_irq_work);
 397         timer_setup(&host->retune_timer, mmc_retune_timer, 0);
 398
 399         /*
 400          * By default, hosts do not support SGIO or large requests.
 401          * They have to set these according to their abilities.
 402          */
 403         host->max_segs = 1;
 404         host->max_seg_size = PAGE_SIZE;
 405
 406         host->max_req_size = PAGE_SIZE;
 407         host->max_blk_size = 512;
 408         host->max_blk_count = PAGE_SIZE / 512;
 409
 410         host->fixed_drv_type = -EINVAL;
 411         host->ios.power_delay_ms = 10;
 412
 413         return host;
 414 }
 415
 416 EXPORT_SYMBOL(mmc_alloc_host);
 417
 418 /**
 419  *      mmc_add_host - initialise host hardware
 420  *      @host: mmc host
 421  *
 422  *      Register the host with the driver model. The host must be
 423  *      prepared to start servicing requests before this function
 424  *      completes.
 425  */
 426 int mmc_add_host(struct mmc_host *host)
 427 {
 428         int err;
 429
 430         WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
 431                 !host->ops->enable_sdio_irq);
 432
 433         err = device_add(&host->class_dev);
 434         if (err)
 435                 return err;
 436
 437         led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
 438
 439 #ifdef CONFIG_DEBUG_FS
 440         mmc_add_host_debugfs(host);
 441 #endif
 442
 443         mmc_start_host(host);
 444         mmc_register_pm_notifier(host);
 445
 446         return 0;
 447 }
 448
 449 EXPORT_SYMBOL(mmc_add_host);
 450
 451 /**
 452  *      mmc_remove_host - remove host hardware
 453  *      @host: mmc host
 454  *
 455  *      Unregister and remove all cards associated with this host,
 456  *      and power down the MMC bus. No new requests will be issued
 457  *      after this function has returned.
 458  */
 459 void mmc_remove_host(struct mmc_host *host)
 460 {
 461         mmc_unregister_pm_notifier(host);
 462         mmc_stop_host(host);
 463
 464 #ifdef CONFIG_DEBUG_FS
 465         mmc_remove_host_debugfs(host);
 466 #endif
 467
 468         device_del(&host->class_dev);
 469
 470         led_trigger_unregister_simple(host->led);
 471 }
 472
 473 EXPORT_SYMBOL(mmc_remove_host);
 474
 475 /**
 476  *      mmc_free_host - free the host structure
 477  *      @host: mmc host
 478  *
 479  *      Free the host once all references to it have been dropped.
 480  */
 481 void mmc_free_host(struct mmc_host *host)
 482 {
 483         mmc_pwrseq_free(host);
 484         put_device(&host->class_dev);
 485 }
 486
 487 EXPORT_SYMBOL(mmc_free_host);