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                 if (host->ops->prepare_hs400_tuning)
 148                         host->ops->prepare_hs400_tuning(host, &host->ios);
 149         }
 150
 151         err = mmc_execute_tuning(host->card);
 152         if (err)
 153                 goto out;
 154
 155         if (return_to_hs400)
 156                 err = mmc_hs200_to_hs400(host->card);
 157 out:
 158         host->doing_retune = 0;
 159
 160         return err;
 161 }
 162
 163 static void mmc_retune_timer(struct timer_list *t)
 164 {
 165         struct mmc_host *host = from_timer(host, t, retune_timer);
 166
 167         mmc_retune_needed(host);
 168 }
 169
 170 /**
 171  *      mmc_of_parse() - parse host's device-tree node
 172  *      @host: host whose node should be parsed.
 173  *
 174  * To keep the rest of the MMC subsystem unaware of whether DT has been
 175  * used to to instantiate and configure this host instance or not, we
 176  * parse the properties and set respective generic mmc-host flags and
 177  * parameters.
 178  */
 179 int mmc_of_parse(struct mmc_host *host)
 180 {
 181         struct device *dev = host->parent;
 182         u32 bus_width, drv_type;
 183         int ret;
 184         bool cd_cap_invert, cd_gpio_invert = false;
 185         bool ro_cap_invert, ro_gpio_invert = false;
 186
 187         if (!dev || !dev_fwnode(dev))
 188                 return 0;
 189
 190         /* "bus-width" is translated to MMC_CAP_*_BIT_DATA flags */
 191         if (device_property_read_u32(dev, "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         device_property_read_u32(dev, "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 (device_property_read_bool(dev, "non-removable")) {
 229                 host->caps |= MMC_CAP_NONREMOVABLE;
 230         } else {
 231                 cd_cap_invert = device_property_read_bool(dev, "cd-inverted");
 232
 233                 if (device_property_read_bool(dev, "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 = device_property_read_bool(dev, "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 (device_property_read_bool(dev, "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 (device_property_read_bool(dev, "cap-sd-highspeed"))
 275                 host->caps |= MMC_CAP_SD_HIGHSPEED;
 276         if (device_property_read_bool(dev, "cap-mmc-highspeed"))
 277                 host->caps |= MMC_CAP_MMC_HIGHSPEED;
 278         if (device_property_read_bool(dev, "sd-uhs-sdr12"))
 279                 host->caps |= MMC_CAP_UHS_SDR12;
 280         if (device_property_read_bool(dev, "sd-uhs-sdr25"))
 281                 host->caps |= MMC_CAP_UHS_SDR25;
 282         if (device_property_read_bool(dev, "sd-uhs-sdr50"))
 283                 host->caps |= MMC_CAP_UHS_SDR50;
 284         if (device_property_read_bool(dev, "sd-uhs-sdr104"))
 285                 host->caps |= MMC_CAP_UHS_SDR104;
 286         if (device_property_read_bool(dev, "sd-uhs-ddr50"))
 287                 host->caps |= MMC_CAP_UHS_DDR50;
 288         if (device_property_read_bool(dev, "cap-power-off-card"))
 289                 host->caps |= MMC_CAP_POWER_OFF_CARD;
 290         if (device_property_read_bool(dev, "cap-mmc-hw-reset"))
 291                 host->caps |= MMC_CAP_HW_RESET;
 292         if (device_property_read_bool(dev, "cap-sdio-irq"))
 293                 host->caps |= MMC_CAP_SDIO_IRQ;
 294         if (device_property_read_bool(dev, "full-pwr-cycle"))
 295                 host->caps2 |= MMC_CAP2_FULL_PWR_CYCLE;
 296         if (device_property_read_bool(dev, "keep-power-in-suspend"))
 297                 host->pm_caps |= MMC_PM_KEEP_POWER;
 298         if (device_property_read_bool(dev, "wakeup-source") ||
 299             device_property_read_bool(dev, "enable-sdio-wakeup")) /* legacy */
 300                 host->pm_caps |= MMC_PM_WAKE_SDIO_IRQ;
 301         if (device_property_read_bool(dev, "mmc-ddr-3_3v"))
 302                 host->caps |= MMC_CAP_3_3V_DDR;
 303         if (device_property_read_bool(dev, "mmc-ddr-1_8v"))
 304                 host->caps |= MMC_CAP_1_8V_DDR;
 305         if (device_property_read_bool(dev, "mmc-ddr-1_2v"))
 306                 host->caps |= MMC_CAP_1_2V_DDR;
 307         if (device_property_read_bool(dev, "mmc-hs200-1_8v"))
 308                 host->caps2 |= MMC_CAP2_HS200_1_8V_SDR;
 309         if (device_property_read_bool(dev, "mmc-hs200-1_2v"))
 310                 host->caps2 |= MMC_CAP2_HS200_1_2V_SDR;
 311         if (device_property_read_bool(dev, "mmc-hs400-1_8v"))
 312                 host->caps2 |= MMC_CAP2_HS400_1_8V | MMC_CAP2_HS200_1_8V_SDR;
 313         if (device_property_read_bool(dev, "mmc-hs400-1_2v"))
 314                 host->caps2 |= MMC_CAP2_HS400_1_2V | MMC_CAP2_HS200_1_2V_SDR;
 315         if (device_property_read_bool(dev, "mmc-hs400-enhanced-strobe"))
 316                 host->caps2 |= MMC_CAP2_HS400_ES;
 317         if (device_property_read_bool(dev, "no-sdio"))
 318                 host->caps2 |= MMC_CAP2_NO_SDIO;
 319         if (device_property_read_bool(dev, "no-sd"))
 320                 host->caps2 |= MMC_CAP2_NO_SD;
 321         if (device_property_read_bool(dev, "no-mmc"))
 322                 host->caps2 |= MMC_CAP2_NO_MMC;
 323
 324         /* Must be after "non-removable" check */
 325         if (device_property_read_u32(dev, "fixed-emmc-driver-type", &drv_type) == 0) {
 326                 if (host->caps & MMC_CAP_NONREMOVABLE)
 327                         host->fixed_drv_type = drv_type;
 328                 else
 329                         dev_err(host->parent,
 330                                 "can't use fixed driver type, media is removable\n");
 331         }
 332
 333         host->dsr_req = !device_property_read_u32(dev, "dsr", &host->dsr);
 334         if (host->dsr_req && (host->dsr & ~0xffff)) {
 335                 dev_err(host->parent,
 336                         "device tree specified broken value for DSR: 0x%x, ignoring\n",
 337                         host->dsr);
 338                 host->dsr_req = 0;
 339         }
 340
 341         return mmc_pwrseq_alloc(host);
 342 }
 343
 344 EXPORT_SYMBOL(mmc_of_parse);
 345
 346 /**
 347  *      mmc_alloc_host - initialise the per-host structure.
 348  *      @extra: sizeof private data structure
 349  *      @dev: pointer to host device model structure
 350  *
 351  *      Initialise the per-host structure.
 352  */
 353 struct mmc_host *mmc_alloc_host(int extra, struct device *dev)
 354 {
 355         int err;
 356         struct mmc_host *host;
 357
 358         host = kzalloc(sizeof(struct mmc_host) + extra, GFP_KERNEL);
 359         if (!host)
 360                 return NULL;
 361
 362         /* scanning will be enabled when we're ready */
 363         host->rescan_disable = 1;
 364
 365         err = ida_simple_get(&mmc_host_ida, 0, 0, GFP_KERNEL);
 366         if (err < 0) {
 367                 kfree(host);
 368                 return NULL;
 369         }
 370
 371         host->index = err;
 372
 373         dev_set_name(&host->class_dev, "mmc%d", host->index);
 374
 375         host->parent = dev;
 376         host->class_dev.parent = dev;
 377         host->class_dev.class = &mmc_host_class;
 378         device_initialize(&host->class_dev);
 379         device_enable_async_suspend(&host->class_dev);
 380
 381         if (mmc_gpio_alloc(host)) {
 382                 put_device(&host->class_dev);
 383                 ida_simple_remove(&mmc_host_ida, host->index);
 384                 kfree(host);
 385                 return NULL;
 386         }
 387
 388         spin_lock_init(&host->lock);
 389         init_waitqueue_head(&host->wq);
 390         INIT_DELAYED_WORK(&host->detect, mmc_rescan);
 391         INIT_DELAYED_WORK(&host->sdio_irq_work, sdio_irq_work);
 392         timer_setup(&host->retune_timer, mmc_retune_timer, 0);
 393
 394         /*
 395          * By default, hosts do not support SGIO or large requests.
 396          * They have to set these according to their abilities.
 397          */
 398         host->max_segs = 1;
 399         host->max_seg_size = PAGE_SIZE;
 400
 401         host->max_req_size = PAGE_SIZE;
 402         host->max_blk_size = 512;
 403         host->max_blk_count = PAGE_SIZE / 512;
 404
 405         host->fixed_drv_type = -EINVAL;
 406
 407         return host;
 408 }
 409
 410 EXPORT_SYMBOL(mmc_alloc_host);
 411
 412 /**
 413  *      mmc_add_host - initialise host hardware
 414  *      @host: mmc host
 415  *
 416  *      Register the host with the driver model. The host must be
 417  *      prepared to start servicing requests before this function
 418  *      completes.
 419  */
 420 int mmc_add_host(struct mmc_host *host)
 421 {
 422         int err;
 423
 424         WARN_ON((host->caps & MMC_CAP_SDIO_IRQ) &&
 425                 !host->ops->enable_sdio_irq);
 426
 427         err = device_add(&host->class_dev);
 428         if (err)
 429                 return err;
 430
 431         led_trigger_register_simple(dev_name(&host->class_dev), &host->led);
 432
 433 #ifdef CONFIG_DEBUG_FS
 434         mmc_add_host_debugfs(host);
 435 #endif
 436
 437         mmc_start_host(host);
 438         mmc_register_pm_notifier(host);
 439
 440         return 0;
 441 }
 442
 443 EXPORT_SYMBOL(mmc_add_host);
 444
 445 /**
 446  *      mmc_remove_host - remove host hardware
 447  *      @host: mmc host
 448  *
 449  *      Unregister and remove all cards associated with this host,
 450  *      and power down the MMC bus. No new requests will be issued
 451  *      after this function has returned.
 452  */
 453 void mmc_remove_host(struct mmc_host *host)
 454 {
 455         mmc_unregister_pm_notifier(host);
 456         mmc_stop_host(host);
 457
 458 #ifdef CONFIG_DEBUG_FS
 459         mmc_remove_host_debugfs(host);
 460 #endif
 461
 462         device_del(&host->class_dev);
 463
 464         led_trigger_unregister_simple(host->led);
 465 }
 466
 467 EXPORT_SYMBOL(mmc_remove_host);
 468
 469 /**
 470  *      mmc_free_host - free the host structure
 471  *      @host: mmc host
 472  *
 473  *      Free the host once all references to it have been dropped.
 474  */
 475 void mmc_free_host(struct mmc_host *host)
 476 {
 477         mmc_pwrseq_free(host);
 478         put_device(&host->class_dev);
 479 }
 480
 481 EXPORT_SYMBOL(mmc_free_host);