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_IDR(mmc_host_idr);
  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         idr_remove(&mmc_host_idr, 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 void mmc_retune_disable(struct mmc_host *host)
  72 {
  73         host->can_retune = 0;
  74         del_timer_sync(&host->retune_timer);
  75         host->retune_now = 0;
  76         host->need_retune = 0;
  77 }
  78
  79 void mmc_retune_timer_stop(struct mmc_host *host)
  80 {
  81         del_timer_sync(&host->retune_timer);
  82 }
  83 EXPORT_SYMBOL(mmc_retune_timer_stop);
  84
  85 void mmc_retune_hold(struct mmc_host *host)
  86 {
  87         if (!host->hold_retune)
  88                 host->retune_now = 1;
  89         host->hold_retune += 1;
  90 }
  91
  92 void mmc_retune_release(struct mmc_host *host)
  93 {
  94         if (host->hold_retune)
  95                 host->hold_retune -= 1;
  96         else
  97                 WARN_ON(1);
  98 }
  99
 100 int mmc_retune(struct mmc_host *host)
 101 {
 102         bool return_to_hs400 = false;
 103         int err;
 104
 105         if (host->retune_now)
 106                 host->retune_now = 0;
 107         else
 108                 return 0;
 109
 110         if (!host->need_retune || host->doing_retune || !host->card)
 111                 return 0;
 112
 113         host->need_retune = 0;
 114
 115         host->doing_retune = 1;
 116
 117         if (host->ios.timing == MMC_TIMING_MMC_HS400) {
 118                 err = mmc_hs400_to_hs200(host->card);
 119                 if (err)
 120                         goto out;
 121
 122                 return_to_hs400 = true;
 123
 124                 if (host->ops->prepare_hs400_tuning)
 125                         host->ops->prepare_hs400_tuning(host, &host->ios);
 126         }
 127
 128         err = mmc_execute_tuning(host->card);
 129         if (err)
 130                 goto out;
 131
 132         if (return_to_hs400)
 133                 err = mmc_hs200_to_hs400(host->card);
 134 out:
 135         host->doing_retune = 0;
 136
 137         return err;
 138 }
 139
 140 static void mmc_retune_timer(unsigned long data)
 141 {
 142         struct mmc_host *host = (struct mmc_host *)data;
 143
 144         mmc_retune_needed(host);
 145 }
 146
 147 /**
 148  *      mmc_of_parse() - parse host's device-tree node
 149  *      @host: host whose node should be parsed.
 150  *
 151  * To keep the rest of the MMC subsystem unaware of whether DT has been
 152  * used to to instantiate and configure this host instance or not, we
 153  * parse the properties and set respective generic mmc-host flags and
 154  * parameters.
 155  */
 156 int mmc_of_parse(struct mmc_host *host)
 157 {
 158         struct device_node *np;
 159         u32 bus_width;
 160         int ret;
 161         bool cd_cap_invert, cd_gpio_invert = false;
 162         bool ro_cap_invert, ro_gpio_invert = false;
 163
 164         if (!host->parent || !host->parent->of_node)
 165                 return 0;
 166
 167         np = host->parent->of_node;
 168
 169         /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
 170         if (of_property_read_u32(np, "bus-width", &bus_width) < 0) {
 171                 dev_dbg(host->parent,
 172                         "\"bus-width\" property is missing, assuming 1 bit.\n");
 173                 bus_width = 1;
 174         }
 175
 176         switch (bus_width) {
 177         case 8:
 178                 host->caps |= MMC_CAP_8_BIT_DATA;
 179                 /* Hosts capable of 8-bit transfers can also do 4 bits */
 180         case 4:
 181                 host->caps |= MMC_CAP_4_BIT_DATA;
 182                 break;
 183         case 1:
 184                 break;
 185         default:
 186                 dev_err(host->parent,
 187                         "Invalid \"bus-width\" value %u!\n", bus_width);
 188                 return -EINVAL;
 189         }
 190
 191         /* f_max is obtained from the optional "max-frequency" property */
 192         of_property_read_u32(np, "max-frequency", &host->f_max);
 193
 194         /*
 195          * Configure CD and WP pins. They are both by default active low to
 196          * match the SDHCI spec. If GPIOs are provided for CD and / or WP, the
 197          * mmc-gpio helpers are used to attach, configure and use them. If
 198          * polarity inversion is specified in DT, one of MMC_CAP2_CD_ACTIVE_HIGH
 199          * and MMC_CAP2_RO_ACTIVE_HIGH capability-2 flags is set. If the
 200          * "broken-cd" property is provided, the MMC_CAP_NEEDS_POLL capability
 201          * is set. If the "non-removable" property is found, the
 202          * MMC_CAP_NONREMOVABLE capability is set and no card-detection
 203          * configuration is performed.
 204          */
 205
 206         /* Parse Card Detection */
 207         if (of_property_read_bool(np, "non-removable")) {
 208                 host->caps |= MMC_CAP_NONREMOVABLE;
 209         } else {
 210                 cd_cap_invert = of_property_read_bool(np, "cd-inverted");
 211
 212                 if (of_property_read_bool(np, "broken-cd"))
 213                         host->caps |= MMC_CAP_NEEDS_POLL;
 214
 215                 ret = mmc_gpiod_request_cd(host, "cd", 0, true,
 216                                            0, &cd_gpio_invert);
 217                 if (!ret)
 218                         dev_info(host->parent, "Got CD GPIO\n");
 219                 else if (ret != -ENOENT && ret != -ENOSYS)
 220                         return ret;
 221
 222                 /*
 223                  * There are two ways to flag that the CD line is inverted:
 224                  * through the cd-inverted flag and by the GPIO line itself
 225                  * being inverted from the GPIO subsystem. This is a leftover
 226                  * from the times when the GPIO subsystem did not make it
 227                  * possible to flag a line as inverted.
 228                  *
 229                  * If the capability on the host AND the GPIO line are
 230                  * both inverted, the end result is that the CD line is
 231                  * not inverted.
 232                  */
 233                 if (cd_cap_invert ^ cd_gpio_invert)
 234                         host->caps2 |= MMC_CAP2_CD_ACTIVE_HIGH;
 235         }
 236
 237         /* Parse Write Protection */
 238         ro_cap_invert = of_property_read_bool(np, "wp-inverted");
 239
 240         ret = mmc_gpiod_request_ro(host, "wp", 0, false, 0, &ro_gpio_invert);
 241         if (!ret)
 242                 dev_info(host->parent, "Got WP GPIO\n");
 243         else if (ret != -ENOENT && ret != -ENOSYS)
 244                 return ret;
 245
 246         if (of_property_read_bool(np, "disable-wp"))
 247                 host->caps2 |= MMC_CAP2_NO_WRITE_PROTECT;
 248
 249         /* See the comment on CD inversion above */
 250         if (ro_cap_invert ^ ro_gpio_invert)
 251                 host->caps2 |= MMC_CAP2_RO_ACTIVE_HIGH;
 252
 253         if (of_property_read_bool(np, "cap-sd-highspeed"))
 254                 host->caps |= MMC_CAP_SD_HIGHSPEED;
 255         if (of_property_read_bool(np, "cap-mmc-highspeed"))
 256                 host->caps |= MMC_CAP_MMC_HIGHSPEED;
 257         if (of_property_read_bool(np, "sd-uhs-sdr12"))
 258                 host->caps |= MMC_CAP_UHS_SDR12;
 259         if (of_property_read_bool(np, "sd-uhs-sdr25"))
 260                 host->caps |= MMC_CAP_UHS_SDR25;
 261         if (of_property_read_bool(np, "sd-uhs-sdr50"))
 262                 host->caps |= MMC_CAP_UHS_SDR50;
 263         if (of_property_read_bool(np, "sd-uhs-sdr104"))
 264                 host->caps |= MMC_CAP_UHS_SDR104;
 265         if (of_property_read_bool(np, "sd-uhs-ddr50"))
 266                 host->caps |= MMC_CAP_UHS_DDR50;
 267         if (of_property_read_bool(np, "cap-power-off-card"))
 268                 host->caps |= MMC_CAP_POWER_OFF_CARD;
 269         if (of_property_read_bool(np, "cap-mmc-hw-reset"))
 270                 host->caps |= MMC_CAP_HW_RESET;
 271         if (of_property_read_bool(np, "cap-sdio-irq"))
 272                 host->caps |= MMC_CAP_SDIO_IRQ;
 273         if (of_property_read_bool(np, "full-pwr-cycle"))
 274                 host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
 275         if (of_property_read_bool(np, "keep-power-in-suspend"))
 276                 host->pm_caps |= MMC_PM_KEEP_POWER;
 277         if (of_property_read_bool(np, "wakeup-source") ||
 278             of_property_read_bool(np, "enable-sdio-wakeup")) /* legacy */
 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         device_enable_async_suspend(&host->class_dev);
 343
 344         if (mmc_gpio_alloc(host)) {
 345                 put_device(&host->class_dev);
 346                 return NULL;
 347         }
 348
 349         spin_lock_init(&host->lock);
 350         init_waitqueue_head(&host->wq);
 351         INIT_DELAYED_WORK(&host->detect, mmc_rescan);
 352         setup_timer(&host->retune_timer, mmc_retune_timer, (unsigned long)host);
 353
 354         /*
 355          * By default, hosts do not support SGIO or large requests.
 356          * They have to set these according to their abilities.
 357          */
 358         host->max_segs = 1;
 359         host->max_seg_size = PAGE_SIZE;
 360
 361         host->max_req_size = PAGE_SIZE;
 362         host->max_blk_size = 512;
 363         host->max_blk_count = PAGE_SIZE / 512;
 364
 365         return host;
 366 }
 367
 368 EXPORT_SYMBOL(mmc_alloc_host);
 369
 370 /**
 371  *      mmc_add_host - initialise host hardware
 372  *      @host: mmc host
 373  *
 374  *      Register the host with the driver model. The host must be
 375  *      prepared to start servicing requests before this function
 376  *      completes.
 377  */
 378 int mmc_add_host(struct mmc_host *host)
 379 {
 380         int err;
 381
 382         WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
 383                 !host->ops->enable_sdio_irq);
 384
 385         err = device_add(&host->class_dev);
 386         if (err)
 387                 return err;
 388
 389         led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
 390
 391 #ifdef CONFIG_DEBUG_FS
 392         mmc_add_host_debugfs(host);
 393 #endif
 394
 395         mmc_start_host(host);
 396         mmc_register_pm_notifier(host);
 397
 398         return 0;
 399 }
 400
 401 EXPORT_SYMBOL(mmc_add_host);
 402
 403 /**
 404  *      mmc_remove_host - remove host hardware
 405  *      @host: mmc host
 406  *
 407  *      Unregister and remove all cards associated with this host,
 408  *      and power down the MMC bus. No new requests will be issued
 409  *      after this function has returned.
 410  */
 411 void mmc_remove_host(struct mmc_host *host)
 412 {
 413         mmc_unregister_pm_notifier(host);
 414         mmc_stop_host(host);
 415
 416 #ifdef CONFIG_DEBUG_FS
 417         mmc_remove_host_debugfs(host);
 418 #endif
 419
 420         device_del(&host->class_dev);
 421
 422         led_trigger_unregister_simple(host->led);
 423 }
 424
 425 EXPORT_SYMBOL(mmc_remove_host);
 426
 427 /**
 428  *      mmc_free_host - free the host structure
 429  *      @host: mmc host
 430  *
 431  *      Free the host once all references to it have been dropped.
 432  */
 433 void mmc_free_host(struct mmc_host *host)
 434 {
 435         mmc_pwrseq_free(host);
 436         put_device(&host->class_dev);
 437 }
 438
 439 EXPORT_SYMBOL(mmc_free_host);