drivers/pinctrl/core.c

   1 /*
   2  * Core driver for the pin control subsystem
   3  *
   4  * Copyright (C) 2011 ST-Ericsson SA
   5  * Written on behalf of Linaro for ST-Ericsson
   6  * Based on bits of regulator core, gpio core and clk core
   7  *
   8  * Author: Linus Walleij <linus.walleij@linaro.org>
   9  *
  10  * License terms: GNU General Public License (GPL) version 2
  11  */
  12 #define pr_fmt(fmt) "pinctrl core: " fmt
  13
  14 #include <linux/kernel.h>
  15 #include <linux/export.h>
  16 #include <linux/init.h>
  17 #include <linux/device.h>
  18 #include <linux/slab.h>
  19 #include <linux/radix-tree.h>
  20 #include <linux/err.h>
  21 #include <linux/list.h>
  22 #include <linux/mutex.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/sysfs.h>
  25 #include <linux/debugfs.h>
  26 #include <linux/seq_file.h>
  27 #include <linux/pinctrl/pinctrl.h>
  28 #include <linux/pinctrl/machine.h>
  29 #include "core.h"
  30 #include "pinmux.h"
  31 #include "pinconf.h"
  32
  33 /* Global list of pin control devices */
  34 static DEFINE_MUTEX(pinctrldev_list_mutex);
  35 static LIST_HEAD(pinctrldev_list);
  36
  37 const char *pinctrl_dev_get_name(struct pinctrl_dev *pctldev)
  38 {
  39         /* We're not allowed to register devices without name */
  40         return pctldev->desc->name;
  41 }
  42 EXPORT_SYMBOL_GPL(pinctrl_dev_get_name);
  43
  44 void *pinctrl_dev_get_drvdata(struct pinctrl_dev *pctldev)
  45 {
  46         return pctldev->driver_data;
  47 }
  48 EXPORT_SYMBOL_GPL(pinctrl_dev_get_drvdata);
  49
  50 /**
  51  * get_pinctrl_dev_from_dev() - look up pin controller device
  52  * @dev: a device pointer, this may be NULL but then devname needs to be
  53  *      defined instead
  54  * @devname: the name of a device instance, as returned by dev_name(), this
  55  *      may be NULL but then dev needs to be defined instead
  56  *
  57  * Looks up a pin control device matching a certain device name or pure device
  58  * pointer, the pure device pointer will take precedence.
  59  */
  60 struct pinctrl_dev *get_pinctrl_dev_from_dev(struct device *dev,
  61                                              const char *devname)
  62 {
  63         struct pinctrl_dev *pctldev = NULL;
  64         bool found = false;
  65
  66         mutex_lock(&pinctrldev_list_mutex);
  67         list_for_each_entry(pctldev, &pinctrldev_list, node) {
  68                 if (dev && pctldev->dev == dev) {
  69                         /* Matched on device pointer */
  70                         found = true;
  71                         break;
  72                 }
  73
  74                 if (devname &&
  75                     !strcmp(dev_name(pctldev->dev), devname)) {
  76                         /* Matched on device name */
  77                         found = true;
  78                         break;
  79                 }
  80         }
  81         mutex_unlock(&pinctrldev_list_mutex);
  82
  83         return found ? pctldev : NULL;
  84 }
  85
  86 struct pin_desc *pin_desc_get(struct pinctrl_dev *pctldev, unsigned int pin)
  87 {
  88         struct pin_desc *pindesc;
  89         unsigned long flags;
  90
  91         spin_lock_irqsave(&pctldev->pin_desc_tree_lock, flags);
  92         pindesc = radix_tree_lookup(&pctldev->pin_desc_tree, pin);
  93         spin_unlock_irqrestore(&pctldev->pin_desc_tree_lock, flags);
  94
  95         return pindesc;
  96 }
  97
  98 /**
  99  * pin_get_from_name() - look up a pin number from a name
 100  * @pctldev: the pin control device to lookup the pin on
 101  * @name: the name of the pin to look up
 102  */
 103 int pin_get_from_name(struct pinctrl_dev *pctldev, const char *name)
 104 {
 105         unsigned i, pin;
 106
 107         /* The pin number can be retrived from the pin controller descriptor */
 108         for (i = 0; i < pctldev->desc->npins; i++) {
 109                 struct pin_desc *desc;
 110
 111                 pin = pctldev->desc->pins[i].number;
 112                 desc = pin_desc_get(pctldev, pin);
 113                 /* Pin space may be sparse */
 114                 if (desc == NULL)
 115                         continue;
 116                 if (desc->name && !strcmp(name, desc->name))
 117                         return pin;
 118         }
 119
 120         return -EINVAL;
 121 }
 122
 123 /**
 124  * pin_is_valid() - check if pin exists on controller
 125  * @pctldev: the pin control device to check the pin on
 126  * @pin: pin to check, use the local pin controller index number
 127  *
 128  * This tells us whether a certain pin exist on a certain pin controller or
 129  * not. Pin lists may be sparse, so some pins may not exist.
 130  */
 131 bool pin_is_valid(struct pinctrl_dev *pctldev, int pin)
 132 {
 133         struct pin_desc *pindesc;
 134
 135         if (pin < 0)
 136                 return false;
 137
 138         pindesc = pin_desc_get(pctldev, pin);
 139         if (pindesc == NULL)
 140                 return false;
 141
 142         return true;
 143 }
 144 EXPORT_SYMBOL_GPL(pin_is_valid);
 145
 146 /* Deletes a range of pin descriptors */
 147 static void pinctrl_free_pindescs(struct pinctrl_dev *pctldev,
 148                                   const struct pinctrl_pin_desc *pins,
 149                                   unsigned num_pins)
 150 {
 151         int i;
 152
 153         spin_lock(&pctldev->pin_desc_tree_lock);
 154         for (i = 0; i < num_pins; i++) {
 155                 struct pin_desc *pindesc;
 156
 157                 pindesc = radix_tree_lookup(&pctldev->pin_desc_tree,
 158                                             pins[i].number);
 159                 if (pindesc != NULL) {
 160                         radix_tree_delete(&pctldev->pin_desc_tree,
 161                                           pins[i].number);
 162                         if (pindesc->dynamic_name)
 163                                 kfree(pindesc->name);
 164                 }
 165                 kfree(pindesc);
 166         }
 167         spin_unlock(&pctldev->pin_desc_tree_lock);
 168 }
 169
 170 static int pinctrl_register_one_pin(struct pinctrl_dev *pctldev,
 171                                     unsigned number, const char *name)
 172 {
 173         struct pin_desc *pindesc;
 174
 175         pindesc = pin_desc_get(pctldev, number);
 176         if (pindesc != NULL) {
 177                 pr_err("pin %d already registered on %s\n", number,
 178                        pctldev->desc->name);
 179                 return -EINVAL;
 180         }
 181
 182         pindesc = kzalloc(sizeof(*pindesc), GFP_KERNEL);
 183         if (pindesc == NULL)
 184                 return -ENOMEM;
 185
 186         spin_lock_init(&pindesc->lock);
 187
 188         /* Set owner */
 189         pindesc->pctldev = pctldev;
 190
 191         /* Copy basic pin info */
 192         if (name) {
 193                 pindesc->name = name;
 194         } else {
 195                 pindesc->name = kasprintf(GFP_KERNEL, "PIN%u", number);
 196                 if (pindesc->name == NULL)
 197                         return -ENOMEM;
 198                 pindesc->dynamic_name = true;
 199         }
 200
 201         spin_lock(&pctldev->pin_desc_tree_lock);
 202         radix_tree_insert(&pctldev->pin_desc_tree, number, pindesc);
 203         spin_unlock(&pctldev->pin_desc_tree_lock);
 204         pr_debug("registered pin %d (%s) on %s\n",
 205                  number, pindesc->name, pctldev->desc->name);
 206         return 0;
 207 }
 208
 209 static int pinctrl_register_pins(struct pinctrl_dev *pctldev,
 210                                  struct pinctrl_pin_desc const *pins,
 211                                  unsigned num_descs)
 212 {
 213         unsigned i;
 214         int ret = 0;
 215
 216         for (i = 0; i < num_descs; i++) {
 217                 ret = pinctrl_register_one_pin(pctldev,
 218                                                pins[i].number, pins[i].name);
 219                 if (ret)
 220                         return ret;
 221         }
 222
 223         return 0;
 224 }
 225
 226 /**
 227  * pinctrl_match_gpio_range() - check if a certain GPIO pin is in range
 228  * @pctldev: pin controller device to check
 229  * @gpio: gpio pin to check taken from the global GPIO pin space
 230  *
 231  * Tries to match a GPIO pin number to the ranges handled by a certain pin
 232  * controller, return the range or NULL
 233  */
 234 static struct pinctrl_gpio_range *
 235 pinctrl_match_gpio_range(struct pinctrl_dev *pctldev, unsigned gpio)
 236 {
 237         struct pinctrl_gpio_range *range = NULL;
 238
 239         /* Loop over the ranges */
 240         mutex_lock(&pctldev->gpio_ranges_lock);
 241         list_for_each_entry(range, &pctldev->gpio_ranges, node) {
 242                 /* Check if we're in the valid range */
 243                 if (gpio >= range->base &&
 244                     gpio < range->base + range->npins) {
 245                         mutex_unlock(&pctldev->gpio_ranges_lock);
 246                         return range;
 247                 }
 248         }
 249         mutex_unlock(&pctldev->gpio_ranges_lock);
 250
 251         return NULL;
 252 }
 253
 254 /**
 255  * pinctrl_get_device_gpio_range() - find device for GPIO range
 256  * @gpio: the pin to locate the pin controller for
 257  * @outdev: the pin control device if found
 258  * @outrange: the GPIO range if found
 259  *
 260  * Find the pin controller handling a certain GPIO pin from the pinspace of
 261  * the GPIO subsystem, return the device and the matching GPIO range. Returns
 262  * negative if the GPIO range could not be found in any device.
 263  */
 264 int pinctrl_get_device_gpio_range(unsigned gpio,
 265                                 struct pinctrl_dev **outdev,
 266                                 struct pinctrl_gpio_range **outrange)
 267 {
 268         struct pinctrl_dev *pctldev = NULL;
 269
 270         /* Loop over the pin controllers */
 271         mutex_lock(&pinctrldev_list_mutex);
 272         list_for_each_entry(pctldev, &pinctrldev_list, node) {
 273                 struct pinctrl_gpio_range *range;
 274
 275                 range = pinctrl_match_gpio_range(pctldev, gpio);
 276                 if (range != NULL) {
 277                         *outdev = pctldev;
 278                         *outrange = range;
 279                         mutex_unlock(&pinctrldev_list_mutex);
 280                         return 0;
 281                 }
 282         }
 283         mutex_unlock(&pinctrldev_list_mutex);
 284
 285         return -EINVAL;
 286 }
 287
 288 /**
 289  * pinctrl_add_gpio_range() - register a GPIO range for a controller
 290  * @pctldev: pin controller device to add the range to
 291  * @range: the GPIO range to add
 292  *
 293  * This adds a range of GPIOs to be handled by a certain pin controller. Call
 294  * this to register handled ranges after registering your pin controller.
 295  */
 296 void pinctrl_add_gpio_range(struct pinctrl_dev *pctldev,
 297                             struct pinctrl_gpio_range *range)
 298 {
 299         mutex_lock(&pctldev->gpio_ranges_lock);
 300         list_add(&range->node, &pctldev->gpio_ranges);
 301         mutex_unlock(&pctldev->gpio_ranges_lock);
 302 }
 303
 304 /**
 305  * pinctrl_remove_gpio_range() - remove a range of GPIOs fro a pin controller
 306  * @pctldev: pin controller device to remove the range from
 307  * @range: the GPIO range to remove
 308  */
 309 void pinctrl_remove_gpio_range(struct pinctrl_dev *pctldev,
 310                                struct pinctrl_gpio_range *range)
 311 {
 312         mutex_lock(&pctldev->gpio_ranges_lock);
 313         list_del(&range->node);
 314         mutex_unlock(&pctldev->gpio_ranges_lock);
 315 }
 316
 317 /**
 318  * pinctrl_get_group_selector() - returns the group selector for a group
 319  * @pctldev: the pin controller handling the group
 320  * @pin_group: the pin group to look up
 321  */
 322 int pinctrl_get_group_selector(struct pinctrl_dev *pctldev,
 323                                const char *pin_group)
 324 {
 325         const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 326         unsigned group_selector = 0;
 327
 328         while (pctlops->list_groups(pctldev, group_selector) >= 0) {
 329                 const char *gname = pctlops->get_group_name(pctldev,
 330                                                             group_selector);
 331                 if (!strcmp(gname, pin_group)) {
 332                         dev_dbg(pctldev->dev,
 333                                 "found group selector %u for %s\n",
 334                                 group_selector,
 335                                 pin_group);
 336                         return group_selector;
 337                 }
 338
 339                 group_selector++;
 340         }
 341
 342         dev_err(pctldev->dev, "does not have pin group %s\n",
 343                 pin_group);
 344
 345         return -EINVAL;
 346 }
 347
 348 #ifdef CONFIG_DEBUG_FS
 349
 350 static int pinctrl_pins_show(struct seq_file *s, void *what)
 351 {
 352         struct pinctrl_dev *pctldev = s->private;
 353         const struct pinctrl_ops *ops = pctldev->desc->pctlops;
 354         unsigned i, pin;
 355
 356         seq_printf(s, "registered pins: %d\n", pctldev->desc->npins);
 357
 358         /* The pin number can be retrived from the pin controller descriptor */
 359         for (i = 0; i < pctldev->desc->npins; i++) {
 360                 struct pin_desc *desc;
 361
 362                 pin = pctldev->desc->pins[i].number;
 363                 desc = pin_desc_get(pctldev, pin);
 364                 /* Pin space may be sparse */
 365                 if (desc == NULL)
 366                         continue;
 367
 368                 seq_printf(s, "pin %d (%s) ", pin,
 369                            desc->name ? desc->name : "unnamed");
 370
 371                 /* Driver-specific info per pin */
 372                 if (ops->pin_dbg_show)
 373                         ops->pin_dbg_show(pctldev, s, pin);
 374
 375                 seq_puts(s, "\n");
 376         }
 377
 378         return 0;
 379 }
 380
 381 static int pinctrl_groups_show(struct seq_file *s, void *what)
 382 {
 383         struct pinctrl_dev *pctldev = s->private;
 384         const struct pinctrl_ops *ops = pctldev->desc->pctlops;
 385         unsigned selector = 0;
 386
 387         /* No grouping */
 388         if (!ops)
 389                 return 0;
 390
 391         seq_puts(s, "registered pin groups:\n");
 392         while (ops->list_groups(pctldev, selector) >= 0) {
 393                 const unsigned *pins;
 394                 unsigned num_pins;
 395                 const char *gname = ops->get_group_name(pctldev, selector);
 396                 int ret;
 397                 int i;
 398
 399                 ret = ops->get_group_pins(pctldev, selector,
 400                                           &pins, &num_pins);
 401                 if (ret)
 402                         seq_printf(s, "%s [ERROR GETTING PINS]\n",
 403                                    gname);
 404                 else {
 405                         seq_printf(s, "group: %s, pins = [ ", gname);
 406                         for (i = 0; i < num_pins; i++)
 407                                 seq_printf(s, "%d ", pins[i]);
 408                         seq_puts(s, "]\n");
 409                 }
 410                 selector++;
 411         }
 412
 413
 414         return 0;
 415 }
 416
 417 static int pinctrl_gpioranges_show(struct seq_file *s, void *what)
 418 {
 419         struct pinctrl_dev *pctldev = s->private;
 420         struct pinctrl_gpio_range *range = NULL;
 421
 422         seq_puts(s, "GPIO ranges handled:\n");
 423
 424         /* Loop over the ranges */
 425         mutex_lock(&pctldev->gpio_ranges_lock);
 426         list_for_each_entry(range, &pctldev->gpio_ranges, node) {
 427                 seq_printf(s, "%u: %s GPIOS [%u - %u] PINS [%u - %u]\n",
 428                            range->id, range->name,
 429                            range->base, (range->base + range->npins - 1),
 430                            range->pin_base,
 431                            (range->pin_base + range->npins - 1));
 432         }
 433         mutex_unlock(&pctldev->gpio_ranges_lock);
 434
 435         return 0;
 436 }
 437
 438 static int pinctrl_devices_show(struct seq_file *s, void *what)
 439 {
 440         struct pinctrl_dev *pctldev;
 441
 442         seq_puts(s, "name [pinmux] [pinconf]\n");
 443         mutex_lock(&pinctrldev_list_mutex);
 444         list_for_each_entry(pctldev, &pinctrldev_list, node) {
 445                 seq_printf(s, "%s ", pctldev->desc->name);
 446                 if (pctldev->desc->pmxops)
 447                         seq_puts(s, "yes ");
 448                 else
 449                         seq_puts(s, "no ");
 450                 if (pctldev->desc->confops)
 451                         seq_puts(s, "yes");
 452                 else
 453                         seq_puts(s, "no");
 454                 seq_puts(s, "\n");
 455         }
 456         mutex_unlock(&pinctrldev_list_mutex);
 457
 458         return 0;
 459 }
 460
 461 static int pinctrl_pins_open(struct inode *inode, struct file *file)
 462 {
 463         return single_open(file, pinctrl_pins_show, inode->i_private);
 464 }
 465
 466 static int pinctrl_groups_open(struct inode *inode, struct file *file)
 467 {
 468         return single_open(file, pinctrl_groups_show, inode->i_private);
 469 }
 470
 471 static int pinctrl_gpioranges_open(struct inode *inode, struct file *file)
 472 {
 473         return single_open(file, pinctrl_gpioranges_show, inode->i_private);
 474 }
 475
 476 static int pinctrl_devices_open(struct inode *inode, struct file *file)
 477 {
 478         return single_open(file, pinctrl_devices_show, NULL);
 479 }
 480
 481 static const struct file_operations pinctrl_pins_ops = {
 482         .open           = pinctrl_pins_open,
 483         .read           = seq_read,
 484         .llseek         = seq_lseek,
 485         .release        = single_release,
 486 };
 487
 488 static const struct file_operations pinctrl_groups_ops = {
 489         .open           = pinctrl_groups_open,
 490         .read           = seq_read,
 491         .llseek         = seq_lseek,
 492         .release        = single_release,
 493 };
 494
 495 static const struct file_operations pinctrl_gpioranges_ops = {
 496         .open           = pinctrl_gpioranges_open,
 497         .read           = seq_read,
 498         .llseek         = seq_lseek,
 499         .release        = single_release,
 500 };
 501
 502 static const struct file_operations pinctrl_devices_ops = {
 503         .open           = pinctrl_devices_open,
 504         .read           = seq_read,
 505         .llseek         = seq_lseek,
 506         .release        = single_release,
 507 };
 508
 509 static struct dentry *debugfs_root;
 510
 511 static void pinctrl_init_device_debugfs(struct pinctrl_dev *pctldev)
 512 {
 513         struct dentry *device_root;
 514
 515         device_root = debugfs_create_dir(dev_name(pctldev->dev),
 516                                          debugfs_root);
 517         pctldev->device_root = device_root;
 518
 519         if (IS_ERR(device_root) || !device_root) {
 520                 pr_warn("failed to create debugfs directory for %s\n",
 521                         dev_name(pctldev->dev));
 522                 return;
 523         }
 524         debugfs_create_file("pins", S_IFREG | S_IRUGO,
 525                             device_root, pctldev, &pinctrl_pins_ops);
 526         debugfs_create_file("pingroups", S_IFREG | S_IRUGO,
 527                             device_root, pctldev, &pinctrl_groups_ops);
 528         debugfs_create_file("gpio-ranges", S_IFREG | S_IRUGO,
 529                             device_root, pctldev, &pinctrl_gpioranges_ops);
 530         pinmux_init_device_debugfs(device_root, pctldev);
 531         pinconf_init_device_debugfs(device_root, pctldev);
 532 }
 533
 534 static void pinctrl_remove_device_debugfs(struct pinctrl_dev *pctldev)
 535 {
 536         debugfs_remove_recursive(pctldev->device_root);
 537 }
 538
 539 static void pinctrl_init_debugfs(void)
 540 {
 541         debugfs_root = debugfs_create_dir("pinctrl", NULL);
 542         if (IS_ERR(debugfs_root) || !debugfs_root) {
 543                 pr_warn("failed to create debugfs directory\n");
 544                 debugfs_root = NULL;
 545                 return;
 546         }
 547
 548         debugfs_create_file("pinctrl-devices", S_IFREG | S_IRUGO,
 549                             debugfs_root, NULL, &pinctrl_devices_ops);
 550         pinmux_init_debugfs(debugfs_root);
 551 }
 552
 553 #else /* CONFIG_DEBUG_FS */
 554
 555 static void pinctrl_init_device_debugfs(struct pinctrl_dev *pctldev)
 556 {
 557 }
 558
 559 static void pinctrl_init_debugfs(void)
 560 {
 561 }
 562
 563 static void pinctrl_remove_device_debugfs(struct pinctrl_dev *pctldev)
 564 {
 565 }
 566
 567 #endif
 568
 569 /**
 570  * pinctrl_register() - register a pin controller device
 571  * @pctldesc: descriptor for this pin controller
 572  * @dev: parent device for this pin controller
 573  * @driver_data: private pin controller data for this pin controller
 574  */
 575 struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
 576                                     struct device *dev, void *driver_data)
 577 {
 578         struct pinctrl_dev *pctldev;
 579         int ret;
 580
 581         if (pctldesc == NULL)
 582                 return NULL;
 583         if (pctldesc->name == NULL)
 584                 return NULL;
 585
 586         pctldev = kzalloc(sizeof(struct pinctrl_dev), GFP_KERNEL);
 587         if (pctldev == NULL)
 588                 return NULL;
 589
 590         /* Initialize pin control device struct */
 591         pctldev->owner = pctldesc->owner;
 592         pctldev->desc = pctldesc;
 593         pctldev->driver_data = driver_data;
 594         INIT_RADIX_TREE(&pctldev->pin_desc_tree, GFP_KERNEL);
 595         spin_lock_init(&pctldev->pin_desc_tree_lock);
 596         INIT_LIST_HEAD(&pctldev->gpio_ranges);
 597         mutex_init(&pctldev->gpio_ranges_lock);
 598         pctldev->dev = dev;
 599
 600         /* If we're implementing pinmuxing, check the ops for sanity */
 601         if (pctldesc->pmxops) {
 602                 ret = pinmux_check_ops(pctldev);
 603                 if (ret) {
 604                         pr_err("%s pinmux ops lacks necessary functions\n",
 605                                pctldesc->name);
 606                         goto out_err;
 607                 }
 608         }
 609
 610         /* If we're implementing pinconfig, check the ops for sanity */
 611         if (pctldesc->confops) {
 612                 ret = pinconf_check_ops(pctldev);
 613                 if (ret) {
 614                         pr_err("%s pin config ops lacks necessary functions\n",
 615                                pctldesc->name);
 616                         goto out_err;
 617                 }
 618         }
 619
 620         /* Register all the pins */
 621         pr_debug("try to register %d pins on %s...\n",
 622                  pctldesc->npins, pctldesc->name);
 623         ret = pinctrl_register_pins(pctldev, pctldesc->pins, pctldesc->npins);
 624         if (ret) {
 625                 pr_err("error during pin registration\n");
 626                 pinctrl_free_pindescs(pctldev, pctldesc->pins,
 627                                       pctldesc->npins);
 628                 goto out_err;
 629         }
 630
 631         pinctrl_init_device_debugfs(pctldev);
 632         mutex_lock(&pinctrldev_list_mutex);
 633         list_add(&pctldev->node, &pinctrldev_list);
 634         mutex_unlock(&pinctrldev_list_mutex);
 635         pinmux_hog_maps(pctldev);
 636         return pctldev;
 637
 638 out_err:
 639         kfree(pctldev);
 640         return NULL;
 641 }
 642 EXPORT_SYMBOL_GPL(pinctrl_register);
 643
 644 /**
 645  * pinctrl_unregister() - unregister pinmux
 646  * @pctldev: pin controller to unregister
 647  *
 648  * Called by pinmux drivers to unregister a pinmux.
 649  */
 650 void pinctrl_unregister(struct pinctrl_dev *pctldev)
 651 {
 652         if (pctldev == NULL)
 653                 return;
 654
 655         pinctrl_remove_device_debugfs(pctldev);
 656         pinmux_unhog_maps(pctldev);
 657         /* TODO: check that no pinmuxes are still active? */
 658         mutex_lock(&pinctrldev_list_mutex);
 659         list_del(&pctldev->node);
 660         mutex_unlock(&pinctrldev_list_mutex);
 661         /* Destroy descriptor tree */
 662         pinctrl_free_pindescs(pctldev, pctldev->desc->pins,
 663                               pctldev->desc->npins);
 664         kfree(pctldev);
 665 }
 666 EXPORT_SYMBOL_GPL(pinctrl_unregister);
 667
 668 static int __init pinctrl_init(void)
 669 {
 670         pr_info("initialized pinctrl subsystem\n");
 671         pinctrl_init_debugfs();
 672         return 0;
 673 }
 674
 675 /* init early since many drivers really need to initialized pinmux early */
 676 core_initcall(pinctrl_init);