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