drivers/pinctrl/pinconf.c

   1 /*
   2  * Core driver for the pin config portions of the pin control subsystem
   3  *
   4  * Copyright (C) 2011 ST-Ericsson SA
   5  * Written on behalf of Linaro for ST-Ericsson
   6  *
   7  * Author: Linus Walleij <linus.walleij@linaro.org>
   8  *
   9  * License terms: GNU General Public License (GPL) version 2
  10  */
  11 #define pr_fmt(fmt) "pinconfig core: " fmt
  12
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/init.h>
  16 #include <linux/device.h>
  17 #include <linux/slab.h>
  18 #include <linux/debugfs.h>
  19 #include <linux/seq_file.h>
  20 #include <linux/uaccess.h>
  21 #include <linux/pinctrl/machine.h>
  22 #include <linux/pinctrl/pinctrl.h>
  23 #include <linux/pinctrl/pinconf.h>
  24 #include "core.h"
  25 #include "pinconf.h"
  26
  27 int pinconf_check_ops(struct pinctrl_dev *pctldev)
  28 {
  29         const struct pinconf_ops *ops = pctldev->desc->confops;
  30
  31         /* We must be able to read out pin status */
  32         if (!ops->pin_config_get && !ops->pin_config_group_get) {
  33                 dev_err(pctldev->dev,
  34                         "pinconf must be able to read out pin status\n");
  35                 return -EINVAL;
  36         }
  37         /* We have to be able to config the pins in SOME way */
  38         if (!ops->pin_config_set && !ops->pin_config_group_set) {
  39                 dev_err(pctldev->dev,
  40                         "pinconf has to be able to set a pins config\n");
  41                 return -EINVAL;
  42         }
  43         return 0;
  44 }
  45
  46 int pinconf_validate_map(struct pinctrl_map const *map, int i)
  47 {
  48         if (!map->data.configs.group_or_pin) {
  49                 pr_err("failed to register map %s (%d): no group/pin given\n",
  50                        map->name, i);
  51                 return -EINVAL;
  52         }
  53
  54         if (!map->data.configs.num_configs ||
  55                         !map->data.configs.configs) {
  56                 pr_err("failed to register map %s (%d): no configs given\n",
  57                        map->name, i);
  58                 return -EINVAL;
  59         }
  60
  61         return 0;
  62 }
  63
  64 int pin_config_get_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
  65                            unsigned long *config)
  66 {
  67         const struct pinconf_ops *ops = pctldev->desc->confops;
  68
  69         if (!ops || !ops->pin_config_get) {
  70                 dev_err(pctldev->dev, "cannot get pin configuration, missing "
  71                         "pin_config_get() function in driver\n");
  72                 return -EINVAL;
  73         }
  74
  75         return ops->pin_config_get(pctldev, pin, config);
  76 }
  77
  78 /**
  79  * pin_config_get() - get the configuration of a single pin parameter
  80  * @dev_name: name of the pin controller device for this pin
  81  * @name: name of the pin to get the config for
  82  * @config: the config pointed to by this argument will be filled in with the
  83  *      current pin state, it can be used directly by drivers as a numeral, or
  84  *      it can be dereferenced to any struct.
  85  */
  86 int pin_config_get(const char *dev_name, const char *name,
  87                           unsigned long *config)
  88 {
  89         struct pinctrl_dev *pctldev;
  90         int pin;
  91
  92         pctldev = get_pinctrl_dev_from_devname(dev_name);
  93         if (!pctldev) {
  94                 pin = -EINVAL;
  95                 return pin;
  96         }
  97
  98         mutex_lock(&pctldev->mutex);
  99
 100         pin = pin_get_from_name(pctldev, name);
 101         if (pin < 0)
 102                 goto unlock;
 103
 104         pin = pin_config_get_for_pin(pctldev, pin, config);
 105
 106 unlock:
 107         mutex_unlock(&pctldev->mutex);
 108         return pin;
 109 }
 110 EXPORT_SYMBOL(pin_config_get);
 111
 112 static int pin_config_set_for_pin(struct pinctrl_dev *pctldev, unsigned pin,
 113                            unsigned long config)
 114 {
 115         const struct pinconf_ops *ops = pctldev->desc->confops;
 116         int ret;
 117
 118         if (!ops || !ops->pin_config_set) {
 119                 dev_err(pctldev->dev, "cannot configure pin, missing "
 120                         "config function in driver\n");
 121                 return -EINVAL;
 122         }
 123
 124         ret = ops->pin_config_set(pctldev, pin, config);
 125         if (ret) {
 126                 dev_err(pctldev->dev,
 127                         "unable to set pin configuration on pin %d\n", pin);
 128                 return ret;
 129         }
 130
 131         return 0;
 132 }
 133
 134 /**
 135  * pin_config_set() - set the configuration of a single pin parameter
 136  * @dev_name: name of pin controller device for this pin
 137  * @name: name of the pin to set the config for
 138  * @config: the config in this argument will contain the desired pin state, it
 139  *      can be used directly by drivers as a numeral, or it can be dereferenced
 140  *      to any struct.
 141  */
 142 int pin_config_set(const char *dev_name, const char *name,
 143                    unsigned long config)
 144 {
 145         struct pinctrl_dev *pctldev;
 146         int pin, ret;
 147
 148         pctldev = get_pinctrl_dev_from_devname(dev_name);
 149         if (!pctldev) {
 150                 ret = -EINVAL;
 151                 return ret;
 152         }
 153
 154         mutex_lock(&pctldev->mutex);
 155
 156         pin = pin_get_from_name(pctldev, name);
 157         if (pin < 0) {
 158                 ret = pin;
 159                 goto unlock;
 160         }
 161
 162         ret = pin_config_set_for_pin(pctldev, pin, config);
 163
 164 unlock:
 165         mutex_unlock(&pctldev->mutex);
 166         return ret;
 167 }
 168 EXPORT_SYMBOL(pin_config_set);
 169
 170 int pin_config_group_get(const char *dev_name, const char *pin_group,
 171                          unsigned long *config)
 172 {
 173         struct pinctrl_dev *pctldev;
 174         const struct pinconf_ops *ops;
 175         int selector, ret;
 176
 177         pctldev = get_pinctrl_dev_from_devname(dev_name);
 178         if (!pctldev) {
 179                 ret = -EINVAL;
 180                 return ret;
 181         }
 182
 183         mutex_lock(&pctldev->mutex);
 184
 185         ops = pctldev->desc->confops;
 186
 187         if (!ops || !ops->pin_config_group_get) {
 188                 dev_err(pctldev->dev, "cannot get configuration for pin "
 189                         "group, missing group config get function in "
 190                         "driver\n");
 191                 ret = -EINVAL;
 192                 goto unlock;
 193         }
 194
 195         selector = pinctrl_get_group_selector(pctldev, pin_group);
 196         if (selector < 0) {
 197                 ret = selector;
 198                 goto unlock;
 199         }
 200
 201         ret = ops->pin_config_group_get(pctldev, selector, config);
 202
 203 unlock:
 204         mutex_unlock(&pctldev->mutex);
 205         return ret;
 206 }
 207 EXPORT_SYMBOL(pin_config_group_get);
 208
 209 int pin_config_group_set(const char *dev_name, const char *pin_group,
 210                          unsigned long config)
 211 {
 212         struct pinctrl_dev *pctldev;
 213         const struct pinconf_ops *ops;
 214         const struct pinctrl_ops *pctlops;
 215         int selector;
 216         const unsigned *pins;
 217         unsigned num_pins;
 218         int ret;
 219         int i;
 220
 221         pctldev = get_pinctrl_dev_from_devname(dev_name);
 222         if (!pctldev) {
 223                 ret = -EINVAL;
 224                 return ret;
 225         }
 226
 227         mutex_lock(&pctldev->mutex);
 228
 229         ops = pctldev->desc->confops;
 230         pctlops = pctldev->desc->pctlops;
 231
 232         if (!ops || (!ops->pin_config_group_set && !ops->pin_config_set)) {
 233                 dev_err(pctldev->dev, "cannot configure pin group, missing "
 234                         "config function in driver\n");
 235                 ret = -EINVAL;
 236                 goto unlock;
 237         }
 238
 239         selector = pinctrl_get_group_selector(pctldev, pin_group);
 240         if (selector < 0) {
 241                 ret = selector;
 242                 goto unlock;
 243         }
 244
 245         ret = pctlops->get_group_pins(pctldev, selector, &pins, &num_pins);
 246         if (ret) {
 247                 dev_err(pctldev->dev, "cannot configure pin group, error "
 248                         "getting pins\n");
 249                 goto unlock;
 250         }
 251
 252         /*
 253          * If the pin controller supports handling entire groups we use that
 254          * capability.
 255          */
 256         if (ops->pin_config_group_set) {
 257                 ret = ops->pin_config_group_set(pctldev, selector, config);
 258                 /*
 259                  * If the pin controller prefer that a certain group be handled
 260                  * pin-by-pin as well, it returns -EAGAIN.
 261                  */
 262                 if (ret != -EAGAIN)
 263                         goto unlock;
 264         }
 265
 266         /*
 267          * If the controller cannot handle entire groups, we configure each pin
 268          * individually.
 269          */
 270         if (!ops->pin_config_set) {
 271                 ret = 0;
 272                 goto unlock;
 273         }
 274
 275         for (i = 0; i < num_pins; i++) {
 276                 ret = ops->pin_config_set(pctldev, pins[i], config);
 277                 if (ret < 0)
 278                         goto unlock;
 279         }
 280
 281         ret = 0;
 282
 283 unlock:
 284         mutex_unlock(&pctldev->mutex);
 285
 286         return ret;
 287 }
 288 EXPORT_SYMBOL(pin_config_group_set);
 289
 290 int pinconf_map_to_setting(struct pinctrl_map const *map,
 291                           struct pinctrl_setting *setting)
 292 {
 293         struct pinctrl_dev *pctldev = setting->pctldev;
 294         int pin;
 295
 296         switch (setting->type) {
 297         case PIN_MAP_TYPE_CONFIGS_PIN:
 298                 pin = pin_get_from_name(pctldev,
 299                                         map->data.configs.group_or_pin);
 300                 if (pin < 0) {
 301                         dev_err(pctldev->dev, "could not map pin config for \"%s\"",
 302                                 map->data.configs.group_or_pin);
 303                         return pin;
 304                 }
 305                 setting->data.configs.group_or_pin = pin;
 306                 break;
 307         case PIN_MAP_TYPE_CONFIGS_GROUP:
 308                 pin = pinctrl_get_group_selector(pctldev,
 309                                          map->data.configs.group_or_pin);
 310                 if (pin < 0) {
 311                         dev_err(pctldev->dev, "could not map group config for \"%s\"",
 312                                 map->data.configs.group_or_pin);
 313                         return pin;
 314                 }
 315                 setting->data.configs.group_or_pin = pin;
 316                 break;
 317         default:
 318                 return -EINVAL;
 319         }
 320
 321         setting->data.configs.num_configs = map->data.configs.num_configs;
 322         setting->data.configs.configs = map->data.configs.configs;
 323
 324         return 0;
 325 }
 326
 327 void pinconf_free_setting(struct pinctrl_setting const *setting)
 328 {
 329 }
 330
 331 int pinconf_apply_setting(struct pinctrl_setting const *setting)
 332 {
 333         struct pinctrl_dev *pctldev = setting->pctldev;
 334         const struct pinconf_ops *ops = pctldev->desc->confops;
 335         int i, ret;
 336
 337         if (!ops) {
 338                 dev_err(pctldev->dev, "missing confops\n");
 339                 return -EINVAL;
 340         }
 341
 342         switch (setting->type) {
 343         case PIN_MAP_TYPE_CONFIGS_PIN:
 344                 if (!ops->pin_config_set) {
 345                         dev_err(pctldev->dev, "missing pin_config_set op\n");
 346                         return -EINVAL;
 347                 }
 348                 for (i = 0; i < setting->data.configs.num_configs; i++) {
 349                         ret = ops->pin_config_set(pctldev,
 350                                         setting->data.configs.group_or_pin,
 351                                         setting->data.configs.configs[i]);
 352                         if (ret < 0) {
 353                                 dev_err(pctldev->dev,
 354                                         "pin_config_set op failed for pin %d config %08lx\n",
 355                                         setting->data.configs.group_or_pin,
 356                                         setting->data.configs.configs[i]);
 357                                 return ret;
 358                         }
 359                 }
 360                 break;
 361         case PIN_MAP_TYPE_CONFIGS_GROUP:
 362                 if (!ops->pin_config_group_set) {
 363                         dev_err(pctldev->dev,
 364                                 "missing pin_config_group_set op\n");
 365                         return -EINVAL;
 366                 }
 367                 for (i = 0; i < setting->data.configs.num_configs; i++) {
 368                         ret = ops->pin_config_group_set(pctldev,
 369                                         setting->data.configs.group_or_pin,
 370                                         setting->data.configs.configs[i]);
 371                         if (ret < 0) {
 372                                 dev_err(pctldev->dev,
 373                                         "pin_config_group_set op failed for group %d config %08lx\n",
 374                                         setting->data.configs.group_or_pin,
 375                                         setting->data.configs.configs[i]);
 376                                 return ret;
 377                         }
 378                 }
 379                 break;
 380         default:
 381                 return -EINVAL;
 382         }
 383
 384         return 0;
 385 }
 386
 387 #ifdef CONFIG_DEBUG_FS
 388
 389 void pinconf_show_map(struct seq_file *s, struct pinctrl_map const *map)
 390 {
 391         struct pinctrl_dev *pctldev;
 392         const struct pinconf_ops *confops;
 393         int i;
 394
 395         pctldev = get_pinctrl_dev_from_devname(map->ctrl_dev_name);
 396         if (pctldev)
 397                 confops = pctldev->desc->confops;
 398         else
 399                 confops = NULL;
 400
 401         switch (map->type) {
 402         case PIN_MAP_TYPE_CONFIGS_PIN:
 403                 seq_printf(s, "pin ");
 404                 break;
 405         case PIN_MAP_TYPE_CONFIGS_GROUP:
 406                 seq_printf(s, "group ");
 407                 break;
 408         default:
 409                 break;
 410         }
 411
 412         seq_printf(s, "%s\n", map->data.configs.group_or_pin);
 413
 414         for (i = 0; i < map->data.configs.num_configs; i++) {
 415                 seq_printf(s, "config ");
 416                 if (confops && confops->pin_config_config_dbg_show)
 417                         confops->pin_config_config_dbg_show(pctldev, s,
 418                                                 map->data.configs.configs[i]);
 419                 else
 420                         seq_printf(s, "%08lx", map->data.configs.configs[i]);
 421                 seq_printf(s, "\n");
 422         }
 423 }
 424
 425 void pinconf_show_setting(struct seq_file *s,
 426                           struct pinctrl_setting const *setting)
 427 {
 428         struct pinctrl_dev *pctldev = setting->pctldev;
 429         const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 430         const struct pinconf_ops *confops = pctldev->desc->confops;
 431         struct pin_desc *desc;
 432         int i;
 433
 434         switch (setting->type) {
 435         case PIN_MAP_TYPE_CONFIGS_PIN:
 436                 desc = pin_desc_get(setting->pctldev,
 437                                     setting->data.configs.group_or_pin);
 438                 seq_printf(s, "pin %s (%d)",
 439                            desc->name ? desc->name : "unnamed",
 440                            setting->data.configs.group_or_pin);
 441                 break;
 442         case PIN_MAP_TYPE_CONFIGS_GROUP:
 443                 seq_printf(s, "group %s (%d)",
 444                            pctlops->get_group_name(pctldev,
 445                                         setting->data.configs.group_or_pin),
 446                            setting->data.configs.group_or_pin);
 447                 break;
 448         default:
 449                 break;
 450         }
 451
 452         /*
 453          * FIXME: We should really get the pin controler to dump the config
 454          * values, so they can be decoded to something meaningful.
 455          */
 456         for (i = 0; i < setting->data.configs.num_configs; i++) {
 457                 seq_printf(s, " ");
 458                 if (confops && confops->pin_config_config_dbg_show)
 459                         confops->pin_config_config_dbg_show(pctldev, s,
 460                                 setting->data.configs.configs[i]);
 461                 else
 462                         seq_printf(s, "%08lx",
 463                                    setting->data.configs.configs[i]);
 464         }
 465
 466         seq_printf(s, "\n");
 467 }
 468
 469 static void pinconf_dump_pin(struct pinctrl_dev *pctldev,
 470                              struct seq_file *s, int pin)
 471 {
 472         const struct pinconf_ops *ops = pctldev->desc->confops;
 473
 474         /* no-op when not using generic pin config */
 475         pinconf_generic_dump_pin(pctldev, s, pin);
 476         if (ops && ops->pin_config_dbg_show)
 477                 ops->pin_config_dbg_show(pctldev, s, pin);
 478 }
 479
 480 static int pinconf_pins_show(struct seq_file *s, void *what)
 481 {
 482         struct pinctrl_dev *pctldev = s->private;
 483         const struct pinconf_ops *ops = pctldev->desc->confops;
 484         unsigned i, pin;
 485
 486         if (!ops || !ops->pin_config_get)
 487                 return 0;
 488
 489         seq_puts(s, "Pin config settings per pin\n");
 490         seq_puts(s, "Format: pin (name): configs\n");
 491
 492         mutex_lock(&pctldev->mutex);
 493
 494         /* The pin number can be retrived from the pin controller descriptor */
 495         for (i = 0; i < pctldev->desc->npins; i++) {
 496                 struct pin_desc *desc;
 497
 498                 pin = pctldev->desc->pins[i].number;
 499                 desc = pin_desc_get(pctldev, pin);
 500                 /* Skip if we cannot search the pin */
 501                 if (desc == NULL)
 502                         continue;
 503
 504                 seq_printf(s, "pin %d (%s):", pin,
 505                            desc->name ? desc->name : "unnamed");
 506
 507                 pinconf_dump_pin(pctldev, s, pin);
 508
 509                 seq_printf(s, "\n");
 510         }
 511
 512         mutex_unlock(&pctldev->mutex);
 513
 514         return 0;
 515 }
 516
 517 static void pinconf_dump_group(struct pinctrl_dev *pctldev,
 518                                struct seq_file *s, unsigned selector,
 519                                const char *gname)
 520 {
 521         const struct pinconf_ops *ops = pctldev->desc->confops;
 522
 523         /* no-op when not using generic pin config */
 524         pinconf_generic_dump_group(pctldev, s, gname);
 525         if (ops && ops->pin_config_group_dbg_show)
 526                 ops->pin_config_group_dbg_show(pctldev, s, selector);
 527 }
 528
 529 static int pinconf_groups_show(struct seq_file *s, void *what)
 530 {
 531         struct pinctrl_dev *pctldev = s->private;
 532         const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 533         const struct pinconf_ops *ops = pctldev->desc->confops;
 534         unsigned ngroups = pctlops->get_groups_count(pctldev);
 535         unsigned selector = 0;
 536
 537         if (!ops || !ops->pin_config_group_get)
 538                 return 0;
 539
 540         seq_puts(s, "Pin config settings per pin group\n");
 541         seq_puts(s, "Format: group (name): configs\n");
 542
 543         while (selector < ngroups) {
 544                 const char *gname = pctlops->get_group_name(pctldev, selector);
 545
 546                 seq_printf(s, "%u (%s):", selector, gname);
 547                 pinconf_dump_group(pctldev, s, selector, gname);
 548                 seq_printf(s, "\n");
 549
 550                 selector++;
 551         }
 552
 553         return 0;
 554 }
 555
 556 static int pinconf_pins_open(struct inode *inode, struct file *file)
 557 {
 558         return single_open(file, pinconf_pins_show, inode->i_private);
 559 }
 560
 561 static int pinconf_groups_open(struct inode *inode, struct file *file)
 562 {
 563         return single_open(file, pinconf_groups_show, inode->i_private);
 564 }
 565
 566 static const struct file_operations pinconf_pins_ops = {
 567         .open           = pinconf_pins_open,
 568         .read           = seq_read,
 569         .llseek         = seq_lseek,
 570         .release        = single_release,
 571 };
 572
 573 static const struct file_operations pinconf_groups_ops = {
 574         .open           = pinconf_groups_open,
 575         .read           = seq_read,
 576         .llseek         = seq_lseek,
 577         .release        = single_release,
 578 };
 579
 580 #define MAX_NAME_LEN 15
 581
 582 struct dbg_cfg {
 583         enum pinctrl_map_type map_type;
 584         char dev_name[MAX_NAME_LEN+1];
 585         char state_name[MAX_NAME_LEN+1];
 586         char pin_name[MAX_NAME_LEN+1];
 587 };
 588
 589 /*
 590  * Goal is to keep this structure as global in order to simply read the
 591  * pinconf-config file after a write to check config is as expected
 592  */
 593 static struct dbg_cfg pinconf_dbg_conf;
 594
 595 /**
 596  * pinconf_dbg_config_print() - display the pinctrl config from the pinctrl
 597  * map, of the dev/pin/state that was last written to pinconf-config file.
 598  * @s: string filled in  with config description
 599  * @d: not used
 600  */
 601 static int pinconf_dbg_config_print(struct seq_file *s, void *d)
 602 {
 603         struct pinctrl_maps *maps_node;
 604         const struct pinctrl_map *map;
 605         struct pinctrl_dev *pctldev = NULL;
 606         const struct pinconf_ops *confops = NULL;
 607         const struct pinctrl_map_configs *configs;
 608         struct dbg_cfg *dbg = &pinconf_dbg_conf;
 609         int i, j;
 610         bool found = false;
 611         unsigned long config;
 612
 613         mutex_lock(&pctldev->mutex);
 614
 615         /* Parse the pinctrl map and look for the elected pin/state */
 616         for_each_maps(maps_node, i, map) {
 617                 if (map->type != dbg->map_type)
 618                         continue;
 619                 if (strcmp(map->dev_name, dbg->dev_name))
 620                         continue;
 621                 if (strcmp(map->name, dbg->state_name))
 622                         continue;
 623
 624                 for (j = 0; j < map->data.configs.num_configs; j++) {
 625                         if (!strcmp(map->data.configs.group_or_pin,
 626                                         dbg->pin_name)) {
 627                                 /*
 628                                  * We found the right pin / state, read the
 629                                  * config and he pctldev for later use
 630                                  */
 631                                 configs = &map->data.configs;
 632                                 pctldev = get_pinctrl_dev_from_devname
 633                                         (map->ctrl_dev_name);
 634                                 found = true;
 635                                 break;
 636                         }
 637                 }
 638         }
 639
 640         if (!found) {
 641                 seq_printf(s, "No config found for dev/state/pin, expected:\n");
 642                 seq_printf(s, "Searched dev:%s\n", dbg->dev_name);
 643                 seq_printf(s, "Searched state:%s\n", dbg->state_name);
 644                 seq_printf(s, "Searched pin:%s\n", dbg->pin_name);
 645                 seq_printf(s, "Use: modify config_pin <devname> "\
 646                                 "<state> <pinname> <value>\n");
 647                 goto exit;
 648         }
 649
 650         config = *(configs->configs);
 651         seq_printf(s, "Dev %s has config of %s in state %s: 0x%08lX\n",
 652                         dbg->dev_name, dbg->pin_name,
 653                         dbg->state_name, config);
 654
 655         if (pctldev)
 656                 confops = pctldev->desc->confops;
 657
 658         if (confops && confops->pin_config_config_dbg_show)
 659                 confops->pin_config_config_dbg_show(pctldev, s, config);
 660
 661 exit:
 662         mutex_unlock(&pctldev->mutex);
 663
 664         return 0;
 665 }
 666
 667 /**
 668  * pinconf_dbg_config_write() - modify the pinctrl config in the pinctrl
 669  * map, of a dev/pin/state entry based on user entries to pinconf-config
 670  * @user_buf: contains the modification request with expected format:
 671  *     modify config_pin <devicename> <state> <pinname> <newvalue>
 672  * modify is literal string, alternatives like add/delete not supported yet
 673  * config_pin is literal, alternatives like config_mux not supported yet
 674  * <devicename> <state> <pinname> are values that should match the pinctrl-maps
 675  * <newvalue> reflects the new config and is driver dependant
 676  */
 677 static int pinconf_dbg_config_write(struct file *file,
 678         const char __user *user_buf, size_t count, loff_t *ppos)
 679 {
 680         struct pinctrl_maps *maps_node;
 681         const struct pinctrl_map *map;
 682         struct pinctrl_dev *pctldev = NULL;
 683         const struct pinconf_ops *confops = NULL;
 684         struct dbg_cfg *dbg = &pinconf_dbg_conf;
 685         const struct pinctrl_map_configs *configs;
 686         char config[MAX_NAME_LEN+1];
 687         bool found = false;
 688         char buf[128];
 689         char *b = &buf[0];
 690         int buf_size;
 691         char *token;
 692         int i;
 693
 694         /* Get userspace string and assure termination */
 695         buf_size = min(count, (sizeof(buf)-1));
 696         if (copy_from_user(buf, user_buf, buf_size))
 697                 return -EFAULT;
 698         buf[buf_size] = 0;
 699
 700         /*
 701          * need to parse entry and extract parameters:
 702          * modify configs_pin devicename state pinname newvalue
 703          */
 704
 705         /* Get arg: 'modify' */
 706         token = strsep(&b, " ");
 707         if (!token)
 708                 return -EINVAL;
 709         if (strcmp(token, "modify"))
 710                 return -EINVAL;
 711
 712         /* Get arg type: "config_pin" type supported so far */
 713         token = strsep(&b, " ");
 714         if (!token)
 715                 return -EINVAL;
 716         if (strcmp(token, "config_pin"))
 717                 return -EINVAL;
 718         dbg->map_type = PIN_MAP_TYPE_CONFIGS_PIN;
 719
 720         /* get arg 'device_name' */
 721         token = strsep(&b, " ");
 722         if (token == NULL)
 723                 return -EINVAL;
 724         if (strlen(token) >= MAX_NAME_LEN)
 725                 return -EINVAL;
 726         strncpy(dbg->dev_name, token, MAX_NAME_LEN);
 727
 728         /* get arg 'state_name' */
 729         token = strsep(&b, " ");
 730         if (token == NULL)
 731                 return -EINVAL;
 732         if (strlen(token) >= MAX_NAME_LEN)
 733                 return -EINVAL;
 734         strncpy(dbg->state_name, token, MAX_NAME_LEN);
 735
 736         /* get arg 'pin_name' */
 737         token = strsep(&b, " ");
 738         if (token == NULL)
 739                 return -EINVAL;
 740         if (strlen(token) >= MAX_NAME_LEN)
 741                 return -EINVAL;
 742         strncpy(dbg->pin_name, token, MAX_NAME_LEN);
 743
 744         /* get new_value of config' */
 745         token = strsep(&b, " ");
 746         if (token == NULL)
 747                 return -EINVAL;
 748         if (strlen(token) >= MAX_NAME_LEN)
 749                 return -EINVAL;
 750         strncpy(config, token, MAX_NAME_LEN);
 751
 752         mutex_lock(&pinctrl_maps_mutex);
 753
 754         /* Parse the pinctrl map and look for the selected dev/state/pin */
 755         for_each_maps(maps_node, i, map) {
 756                 if (strcmp(map->dev_name, dbg->dev_name))
 757                         continue;
 758                 if (map->type != dbg->map_type)
 759                         continue;
 760                 if (strcmp(map->name, dbg->state_name))
 761                         continue;
 762
 763                 /*  we found the right pin / state, so overwrite config */
 764                 if (!strcmp(map->data.configs.group_or_pin, dbg->pin_name)) {
 765                         found = true;
 766                         pctldev = get_pinctrl_dev_from_devname(
 767                                         map->ctrl_dev_name);
 768                         configs = &map->data.configs;
 769                         break;
 770                 }
 771         }
 772
 773         if (!found) {
 774                 count = -EINVAL;
 775                 goto exit;
 776         }
 777
 778         if (pctldev)
 779                 confops = pctldev->desc->confops;
 780
 781         if (confops && confops->pin_config_dbg_parse_modify) {
 782                 for (i = 0; i < configs->num_configs; i++) {
 783                         confops->pin_config_dbg_parse_modify(pctldev,
 784                                                      config,
 785                                                      &configs->configs[i]);
 786                 }
 787         }
 788
 789 exit:
 790         mutex_unlock(&pinctrl_maps_mutex);
 791
 792         return count;
 793 }
 794
 795 static int pinconf_dbg_config_open(struct inode *inode, struct file *file)
 796 {
 797         return single_open(file, pinconf_dbg_config_print, inode->i_private);
 798 }
 799
 800 static const struct file_operations pinconf_dbg_pinconfig_fops = {
 801         .open = pinconf_dbg_config_open,
 802         .write = pinconf_dbg_config_write,
 803         .read = seq_read,
 804         .llseek = seq_lseek,
 805         .release = single_release,
 806         .owner = THIS_MODULE,
 807 };
 808
 809 void pinconf_init_device_debugfs(struct dentry *devroot,
 810                          struct pinctrl_dev *pctldev)
 811 {
 812         debugfs_create_file("pinconf-pins", S_IFREG | S_IRUGO,
 813                             devroot, pctldev, &pinconf_pins_ops);
 814         debugfs_create_file("pinconf-groups", S_IFREG | S_IRUGO,
 815                             devroot, pctldev, &pinconf_groups_ops);
 816         debugfs_create_file("pinconf-config",  (S_IRUGO | S_IWUSR | S_IWGRP),
 817                             devroot, pctldev, &pinconf_dbg_pinconfig_fops);
 818 }
 819
 820 #endif