drivers/pinctrl/pinmux.c

   1 /*
   2  * Core driver for the pin muxing portions of the pin control subsystem
   3  *
   4  * Copyright (C) 2011-2012 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  * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
  11  *
  12  * License terms: GNU General Public License (GPL) version 2
  13  */
  14 #define pr_fmt(fmt) "pinmux core: " fmt
  15
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/init.h>
  19 #include <linux/device.h>
  20 #include <linux/slab.h>
  21 #include <linux/radix-tree.h>
  22 #include <linux/err.h>
  23 #include <linux/list.h>
  24 #include <linux/string.h>
  25 #include <linux/sysfs.h>
  26 #include <linux/debugfs.h>
  27 #include <linux/seq_file.h>
  28 #include <linux/pinctrl/machine.h>
  29 #include <linux/pinctrl/pinmux.h>
  30 #include "core.h"
  31 #include "pinmux.h"
  32
  33 int pinmux_check_ops(struct pinctrl_dev *pctldev)
  34 {
  35         const struct pinmux_ops *ops = pctldev->desc->pmxops;
  36         unsigned nfuncs;
  37         unsigned selector = 0;
  38
  39         /* Check that we implement required operations */
  40         if (!ops ||
  41             !ops->get_functions_count ||
  42             !ops->get_function_name ||
  43             !ops->get_function_groups ||
  44             !ops->set_mux) {
  45                 dev_err(pctldev->dev, "pinmux ops lacks necessary functions\n");
  46                 return -EINVAL;
  47         }
  48         /* Check that all functions registered have names */
  49         nfuncs = ops->get_functions_count(pctldev);
  50         while (selector < nfuncs) {
  51                 const char *fname = ops->get_function_name(pctldev,
  52                                                            selector);
  53                 if (!fname) {
  54                         dev_err(pctldev->dev, "pinmux ops has no name for function%u\n",
  55                                 selector);
  56                         return -EINVAL;
  57                 }
  58                 selector++;
  59         }
  60
  61         return 0;
  62 }
  63
  64 int pinmux_validate_map(const struct pinctrl_map *map, int i)
  65 {
  66         if (!map->data.mux.function) {
  67                 pr_err("failed to register map %s (%d): no function given\n",
  68                        map->name, i);
  69                 return -EINVAL;
  70         }
  71
  72         return 0;
  73 }
  74
  75 /**
  76  * pin_request() - request a single pin to be muxed in, typically for GPIO
  77  * @pin: the pin number in the global pin space
  78  * @owner: a representation of the owner of this pin; typically the device
  79  *      name that controls its mux function, or the requested GPIO name
  80  * @gpio_range: the range matching the GPIO pin if this is a request for a
  81  *      single GPIO pin
  82  */
  83 static int pin_request(struct pinctrl_dev *pctldev,
  84                        int pin, const char *owner,
  85                        struct pinctrl_gpio_range *gpio_range)
  86 {
  87         struct pin_desc *desc;
  88         const struct pinmux_ops *ops = pctldev->desc->pmxops;
  89         int status = -EINVAL;
  90
  91         desc = pin_desc_get(pctldev, pin);
  92         if (desc == NULL) {
  93                 dev_err(pctldev->dev,
  94                         "pin %d is not registered so it cannot be requested\n",
  95                         pin);
  96                 goto out;
  97         }
  98
  99         dev_dbg(pctldev->dev, "request pin %d (%s) for %s\n",
 100                 pin, desc->name, owner);
 101
 102         if ((!gpio_range || ops->strict) &&
 103             desc->mux_usecount && strcmp(desc->mux_owner, owner)) {
 104                 dev_err(pctldev->dev,
 105                         "pin %s already requested by %s; cannot claim for %s\n",
 106                         desc->name, desc->mux_owner, owner);
 107                 goto out;
 108         }
 109
 110         if ((gpio_range || ops->strict) && desc->gpio_owner) {
 111                 dev_err(pctldev->dev,
 112                         "pin %s already requested by %s; cannot claim for %s\n",
 113                         desc->name, desc->gpio_owner, owner);
 114                 goto out;
 115         }
 116
 117         if (gpio_range) {
 118                 desc->gpio_owner = owner;
 119         } else {
 120                 desc->mux_usecount++;
 121                 if (desc->mux_usecount > 1)
 122                         return 0;
 123
 124                 desc->mux_owner = owner;
 125         }
 126
 127         /* Let each pin increase references to this module */
 128         if (!try_module_get(pctldev->owner)) {
 129                 dev_err(pctldev->dev,
 130                         "could not increase module refcount for pin %d\n",
 131                         pin);
 132                 status = -EINVAL;
 133                 goto out_free_pin;
 134         }
 135
 136         /*
 137          * If there is no kind of request function for the pin we just assume
 138          * we got it by default and proceed.
 139          */
 140         if (gpio_range && ops->gpio_request_enable)
 141                 /* This requests and enables a single GPIO pin */
 142                 status = ops->gpio_request_enable(pctldev, gpio_range, pin);
 143         else if (ops->request)
 144                 status = ops->request(pctldev, pin);
 145         else
 146                 status = 0;
 147
 148         if (status) {
 149                 dev_err(pctldev->dev, "request() failed for pin %d\n", pin);
 150                 module_put(pctldev->owner);
 151         }
 152
 153 out_free_pin:
 154         if (status) {
 155                 if (gpio_range) {
 156                         desc->gpio_owner = NULL;
 157                 } else {
 158                         desc->mux_usecount--;
 159                         if (!desc->mux_usecount)
 160                                 desc->mux_owner = NULL;
 161                 }
 162         }
 163 out:
 164         if (status)
 165                 dev_err(pctldev->dev, "pin-%d (%s) status %d\n",
 166                         pin, owner, status);
 167
 168         return status;
 169 }
 170
 171 /**
 172  * pin_free() - release a single muxed in pin so something else can be muxed
 173  * @pctldev: pin controller device handling this pin
 174  * @pin: the pin to free
 175  * @gpio_range: the range matching the GPIO pin if this is a request for a
 176  *      single GPIO pin
 177  *
 178  * This function returns a pointer to the previous owner. This is used
 179  * for callers that dynamically allocate an owner name so it can be freed
 180  * once the pin is free. This is done for GPIO request functions.
 181  */
 182 static const char *pin_free(struct pinctrl_dev *pctldev, int pin,
 183                             struct pinctrl_gpio_range *gpio_range)
 184 {
 185         const struct pinmux_ops *ops = pctldev->desc->pmxops;
 186         struct pin_desc *desc;
 187         const char *owner;
 188
 189         desc = pin_desc_get(pctldev, pin);
 190         if (desc == NULL) {
 191                 dev_err(pctldev->dev,
 192                         "pin is not registered so it cannot be freed\n");
 193                 return NULL;
 194         }
 195
 196         if (!gpio_range) {
 197                 /*
 198                  * A pin should not be freed more times than allocated.
 199                  */
 200                 if (WARN_ON(!desc->mux_usecount))
 201                         return NULL;
 202                 desc->mux_usecount--;
 203                 if (desc->mux_usecount)
 204                         return NULL;
 205         }
 206
 207         /*
 208          * If there is no kind of request function for the pin we just assume
 209          * we got it by default and proceed.
 210          */
 211         if (gpio_range && ops->gpio_disable_free)
 212                 ops->gpio_disable_free(pctldev, gpio_range, pin);
 213         else if (ops->free)
 214                 ops->free(pctldev, pin);
 215
 216         if (gpio_range) {
 217                 owner = desc->gpio_owner;
 218                 desc->gpio_owner = NULL;
 219         } else {
 220                 owner = desc->mux_owner;
 221                 desc->mux_owner = NULL;
 222                 desc->mux_setting = NULL;
 223         }
 224
 225         module_put(pctldev->owner);
 226
 227         return owner;
 228 }
 229
 230 /**
 231  * pinmux_request_gpio() - request pinmuxing for a GPIO pin
 232  * @pctldev: pin controller device affected
 233  * @pin: the pin to mux in for GPIO
 234  * @range: the applicable GPIO range
 235  */
 236 int pinmux_request_gpio(struct pinctrl_dev *pctldev,
 237                         struct pinctrl_gpio_range *range,
 238                         unsigned pin, unsigned gpio)
 239 {
 240         const char *owner;
 241         int ret;
 242
 243         /* Conjure some name stating what chip and pin this is taken by */
 244         owner = kasprintf(GFP_KERNEL, "%s:%d", range->name, gpio);
 245         if (!owner)
 246                 return -ENOMEM;
 247
 248         ret = pin_request(pctldev, pin, owner, range);
 249         if (ret < 0)
 250                 kfree(owner);
 251
 252         return ret;
 253 }
 254
 255 /**
 256  * pinmux_free_gpio() - release a pin from GPIO muxing
 257  * @pctldev: the pin controller device for the pin
 258  * @pin: the affected currently GPIO-muxed in pin
 259  * @range: applicable GPIO range
 260  */
 261 void pinmux_free_gpio(struct pinctrl_dev *pctldev, unsigned pin,
 262                       struct pinctrl_gpio_range *range)
 263 {
 264         const char *owner;
 265
 266         owner = pin_free(pctldev, pin, range);
 267         kfree(owner);
 268 }
 269
 270 /**
 271  * pinmux_gpio_direction() - set the direction of a single muxed-in GPIO pin
 272  * @pctldev: the pin controller handling this pin
 273  * @range: applicable GPIO range
 274  * @pin: the affected GPIO pin in this controller
 275  * @input: true if we set the pin as input, false for output
 276  */
 277 int pinmux_gpio_direction(struct pinctrl_dev *pctldev,
 278                           struct pinctrl_gpio_range *range,
 279                           unsigned pin, bool input)
 280 {
 281         const struct pinmux_ops *ops;
 282         int ret;
 283
 284         ops = pctldev->desc->pmxops;
 285
 286         if (ops->gpio_set_direction)
 287                 ret = ops->gpio_set_direction(pctldev, range, pin, input);
 288         else
 289                 ret = 0;
 290
 291         return ret;
 292 }
 293
 294 static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
 295                                         const char *function)
 296 {
 297         const struct pinmux_ops *ops = pctldev->desc->pmxops;
 298         unsigned nfuncs = ops->get_functions_count(pctldev);
 299         unsigned selector = 0;
 300
 301         /* See if this pctldev has this function */
 302         while (selector < nfuncs) {
 303                 const char *fname = ops->get_function_name(pctldev, selector);
 304
 305                 if (!strcmp(function, fname))
 306                         return selector;
 307
 308                 selector++;
 309         }
 310
 311         dev_err(pctldev->dev, "function '%s' not supported\n", function);
 312         return -EINVAL;
 313 }
 314
 315 int pinmux_map_to_setting(const struct pinctrl_map *map,
 316                           struct pinctrl_setting *setting)
 317 {
 318         struct pinctrl_dev *pctldev = setting->pctldev;
 319         const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
 320         char const * const *groups;
 321         unsigned num_groups;
 322         int ret;
 323         const char *group;
 324
 325         if (!pmxops) {
 326                 dev_err(pctldev->dev, "does not support mux function\n");
 327                 return -EINVAL;
 328         }
 329
 330         ret = pinmux_func_name_to_selector(pctldev, map->data.mux.function);
 331         if (ret < 0) {
 332                 dev_err(pctldev->dev, "invalid function %s in map table\n",
 333                         map->data.mux.function);
 334                 return ret;
 335         }
 336         setting->data.mux.func = ret;
 337
 338         ret = pmxops->get_function_groups(pctldev, setting->data.mux.func,
 339                                           &groups, &num_groups);
 340         if (ret < 0) {
 341                 dev_err(pctldev->dev, "can't query groups for function %s\n",
 342                         map->data.mux.function);
 343                 return ret;
 344         }
 345         if (!num_groups) {
 346                 dev_err(pctldev->dev,
 347                         "function %s can't be selected on any group\n",
 348                         map->data.mux.function);
 349                 return -EINVAL;
 350         }
 351         if (map->data.mux.group) {
 352                 group = map->data.mux.group;
 353                 ret = match_string(groups, num_groups, group);
 354                 if (ret < 0) {
 355                         dev_err(pctldev->dev,
 356                                 "invalid group \"%s\" for function \"%s\"\n",
 357                                 group, map->data.mux.function);
 358                         return ret;
 359                 }
 360         } else {
 361                 group = groups[0];
 362         }
 363
 364         ret = pinctrl_get_group_selector(pctldev, group);
 365         if (ret < 0) {
 366                 dev_err(pctldev->dev, "invalid group %s in map table\n",
 367                         map->data.mux.group);
 368                 return ret;
 369         }
 370         setting->data.mux.group = ret;
 371
 372         return 0;
 373 }
 374
 375 void pinmux_free_setting(const struct pinctrl_setting *setting)
 376 {
 377         /* This function is currently unused */
 378 }
 379
 380 int pinmux_enable_setting(const struct pinctrl_setting *setting)
 381 {
 382         struct pinctrl_dev *pctldev = setting->pctldev;
 383         const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 384         const struct pinmux_ops *ops = pctldev->desc->pmxops;
 385         int ret = 0;
 386         const unsigned *pins = NULL;
 387         unsigned num_pins = 0;
 388         int i;
 389         struct pin_desc *desc;
 390
 391         if (pctlops->get_group_pins)
 392                 ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
 393                                               &pins, &num_pins);
 394
 395         if (ret) {
 396                 const char *gname;
 397
 398                 /* errors only affect debug data, so just warn */
 399                 gname = pctlops->get_group_name(pctldev,
 400                                                 setting->data.mux.group);
 401                 dev_warn(pctldev->dev,
 402                          "could not get pins for group %s\n",
 403                          gname);
 404                 num_pins = 0;
 405         }
 406
 407         /* Try to allocate all pins in this group, one by one */
 408         for (i = 0; i < num_pins; i++) {
 409                 ret = pin_request(pctldev, pins[i], setting->dev_name, NULL);
 410                 if (ret) {
 411                         const char *gname;
 412                         const char *pname;
 413
 414                         desc = pin_desc_get(pctldev, pins[i]);
 415                         pname = desc ? desc->name : "non-existing";
 416                         gname = pctlops->get_group_name(pctldev,
 417                                                 setting->data.mux.group);
 418                         dev_err(pctldev->dev,
 419                                 "could not request pin %d (%s) from group %s "
 420                                 " on device %s\n",
 421                                 pins[i], pname, gname,
 422                                 pinctrl_dev_get_name(pctldev));
 423                         goto err_pin_request;
 424                 }
 425         }
 426
 427         /* Now that we have acquired the pins, encode the mux setting */
 428         for (i = 0; i < num_pins; i++) {
 429                 desc = pin_desc_get(pctldev, pins[i]);
 430                 if (desc == NULL) {
 431                         dev_warn(pctldev->dev,
 432                                  "could not get pin desc for pin %d\n",
 433                                  pins[i]);
 434                         continue;
 435                 }
 436                 desc->mux_setting = &(setting->data.mux);
 437         }
 438
 439         ret = ops->set_mux(pctldev, setting->data.mux.func,
 440                            setting->data.mux.group);
 441
 442         if (ret)
 443                 goto err_set_mux;
 444
 445         return 0;
 446
 447 err_set_mux:
 448         for (i = 0; i < num_pins; i++) {
 449                 desc = pin_desc_get(pctldev, pins[i]);
 450                 if (desc)
 451                         desc->mux_setting = NULL;
 452         }
 453 err_pin_request:
 454         /* On error release all taken pins */
 455         while (--i >= 0)
 456                 pin_free(pctldev, pins[i], NULL);
 457
 458         return ret;
 459 }
 460
 461 void pinmux_disable_setting(const struct pinctrl_setting *setting)
 462 {
 463         struct pinctrl_dev *pctldev = setting->pctldev;
 464         const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 465         int ret = 0;
 466         const unsigned *pins = NULL;
 467         unsigned num_pins = 0;
 468         int i;
 469         struct pin_desc *desc;
 470
 471         if (pctlops->get_group_pins)
 472                 ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
 473                                               &pins, &num_pins);
 474         if (ret) {
 475                 const char *gname;
 476
 477                 /* errors only affect debug data, so just warn */
 478                 gname = pctlops->get_group_name(pctldev,
 479                                                 setting->data.mux.group);
 480                 dev_warn(pctldev->dev,
 481                          "could not get pins for group %s\n",
 482                          gname);
 483                 num_pins = 0;
 484         }
 485
 486         /* Flag the descs that no setting is active */
 487         for (i = 0; i < num_pins; i++) {
 488                 desc = pin_desc_get(pctldev, pins[i]);
 489                 if (desc == NULL) {
 490                         dev_warn(pctldev->dev,
 491                                  "could not get pin desc for pin %d\n",
 492                                  pins[i]);
 493                         continue;
 494                 }
 495                 if (desc->mux_setting == &(setting->data.mux)) {
 496                         pin_free(pctldev, pins[i], NULL);
 497                 } else {
 498                         const char *gname;
 499
 500                         gname = pctlops->get_group_name(pctldev,
 501                                                 setting->data.mux.group);
 502                         dev_warn(pctldev->dev,
 503                                  "not freeing pin %d (%s) as part of "
 504                                  "deactivating group %s - it is already "
 505                                  "used for some other setting",
 506                                  pins[i], desc->name, gname);
 507                 }
 508         }
 509 }
 510
 511 #ifdef CONFIG_DEBUG_FS
 512
 513 /* Called from pincontrol core */
 514 static int pinmux_functions_show(struct seq_file *s, void *what)
 515 {
 516         struct pinctrl_dev *pctldev = s->private;
 517         const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
 518         unsigned nfuncs;
 519         unsigned func_selector = 0;
 520
 521         if (!pmxops)
 522                 return 0;
 523
 524         mutex_lock(&pctldev->mutex);
 525         nfuncs = pmxops->get_functions_count(pctldev);
 526         while (func_selector < nfuncs) {
 527                 const char *func = pmxops->get_function_name(pctldev,
 528                                                           func_selector);
 529                 const char * const *groups;
 530                 unsigned num_groups;
 531                 int ret;
 532                 int i;
 533
 534                 ret = pmxops->get_function_groups(pctldev, func_selector,
 535                                                   &groups, &num_groups);
 536                 if (ret) {
 537                         seq_printf(s, "function %s: COULD NOT GET GROUPS\n",
 538                                    func);
 539                         func_selector++;
 540                         continue;
 541                 }
 542
 543                 seq_printf(s, "function: %s, groups = [ ", func);
 544                 for (i = 0; i < num_groups; i++)
 545                         seq_printf(s, "%s ", groups[i]);
 546                 seq_puts(s, "]\n");
 547
 548                 func_selector++;
 549         }
 550
 551         mutex_unlock(&pctldev->mutex);
 552
 553         return 0;
 554 }
 555
 556 static int pinmux_pins_show(struct seq_file *s, void *what)
 557 {
 558         struct pinctrl_dev *pctldev = s->private;
 559         const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 560         const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
 561         unsigned i, pin;
 562
 563         if (!pmxops)
 564                 return 0;
 565
 566         seq_puts(s, "Pinmux settings per pin\n");
 567         if (pmxops->strict)
 568                 seq_puts(s,
 569                  "Format: pin (name): mux_owner|gpio_owner (strict) hog?\n");
 570         else
 571                 seq_puts(s,
 572                 "Format: pin (name): mux_owner gpio_owner hog?\n");
 573
 574         mutex_lock(&pctldev->mutex);
 575
 576         /* The pin number can be retrived from the pin controller descriptor */
 577         for (i = 0; i < pctldev->desc->npins; i++) {
 578                 struct pin_desc *desc;
 579                 bool is_hog = false;
 580
 581                 pin = pctldev->desc->pins[i].number;
 582                 desc = pin_desc_get(pctldev, pin);
 583                 /* Skip if we cannot search the pin */
 584                 if (desc == NULL)
 585                         continue;
 586
 587                 if (desc->mux_owner &&
 588                     !strcmp(desc->mux_owner, pinctrl_dev_get_name(pctldev)))
 589                         is_hog = true;
 590
 591                 if (pmxops->strict) {
 592                         if (desc->mux_owner)
 593                                 seq_printf(s, "pin %d (%s): device %s%s",
 594                                            pin, desc->name, desc->mux_owner,
 595                                            is_hog ? " (HOG)" : "");
 596                         else if (desc->gpio_owner)
 597                                 seq_printf(s, "pin %d (%s): GPIO %s",
 598                                            pin, desc->name, desc->gpio_owner);
 599                         else
 600                                 seq_printf(s, "pin %d (%s): UNCLAIMED",
 601                                            pin, desc->name);
 602                 } else {
 603                         /* For non-strict controllers */
 604                         seq_printf(s, "pin %d (%s): %s %s%s", pin, desc->name,
 605                                    desc->mux_owner ? desc->mux_owner
 606                                    : "(MUX UNCLAIMED)",
 607                                    desc->gpio_owner ? desc->gpio_owner
 608                                    : "(GPIO UNCLAIMED)",
 609                                    is_hog ? " (HOG)" : "");
 610                 }
 611
 612                 /* If mux: print function+group claiming the pin */
 613                 if (desc->mux_setting)
 614                         seq_printf(s, " function %s group %s\n",
 615                                    pmxops->get_function_name(pctldev,
 616                                         desc->mux_setting->func),
 617                                    pctlops->get_group_name(pctldev,
 618                                         desc->mux_setting->group));
 619                 else
 620                         seq_putc(s, '\n');
 621         }
 622
 623         mutex_unlock(&pctldev->mutex);
 624
 625         return 0;
 626 }
 627
 628 void pinmux_show_map(struct seq_file *s, const struct pinctrl_map *map)
 629 {
 630         seq_printf(s, "group %s\nfunction %s\n",
 631                 map->data.mux.group ? map->data.mux.group : "(default)",
 632                 map->data.mux.function);
 633 }
 634
 635 void pinmux_show_setting(struct seq_file *s,
 636                          const struct pinctrl_setting *setting)
 637 {
 638         struct pinctrl_dev *pctldev = setting->pctldev;
 639         const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
 640         const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
 641
 642         seq_printf(s, "group: %s (%u) function: %s (%u)\n",
 643                    pctlops->get_group_name(pctldev, setting->data.mux.group),
 644                    setting->data.mux.group,
 645                    pmxops->get_function_name(pctldev, setting->data.mux.func),
 646                    setting->data.mux.func);
 647 }
 648
 649 static int pinmux_functions_open(struct inode *inode, struct file *file)
 650 {
 651         return single_open(file, pinmux_functions_show, inode->i_private);
 652 }
 653
 654 static int pinmux_pins_open(struct inode *inode, struct file *file)
 655 {
 656         return single_open(file, pinmux_pins_show, inode->i_private);
 657 }
 658
 659 static const struct file_operations pinmux_functions_ops = {
 660         .open           = pinmux_functions_open,
 661         .read           = seq_read,
 662         .llseek         = seq_lseek,
 663         .release        = single_release,
 664 };
 665
 666 static const struct file_operations pinmux_pins_ops = {
 667         .open           = pinmux_pins_open,
 668         .read           = seq_read,
 669         .llseek         = seq_lseek,
 670         .release        = single_release,
 671 };
 672
 673 void pinmux_init_device_debugfs(struct dentry *devroot,
 674                          struct pinctrl_dev *pctldev)
 675 {
 676         debugfs_create_file("pinmux-functions", S_IFREG | S_IRUGO,
 677                             devroot, pctldev, &pinmux_functions_ops);
 678         debugfs_create_file("pinmux-pins", S_IFREG | S_IRUGO,
 679                             devroot, pctldev, &pinmux_pins_ops);
 680 }
 681
 682 #endif /* CONFIG_DEBUG_FS */
 683
 684 #ifdef CONFIG_GENERIC_PINMUX_FUNCTIONS
 685
 686 /**
 687  * pinmux_generic_get_function_count() - returns number of functions
 688  * @pctldev: pin controller device
 689  */
 690 int pinmux_generic_get_function_count(struct pinctrl_dev *pctldev)
 691 {
 692         return pctldev->num_functions;
 693 }
 694 EXPORT_SYMBOL_GPL(pinmux_generic_get_function_count);
 695
 696 /**
 697  * pinmux_generic_get_function_name() - returns the function name
 698  * @pctldev: pin controller device
 699  * @selector: function number
 700  */
 701 const char *
 702 pinmux_generic_get_function_name(struct pinctrl_dev *pctldev,
 703                                  unsigned int selector)
 704 {
 705         struct function_desc *function;
 706
 707         function = radix_tree_lookup(&pctldev->pin_function_tree,
 708                                      selector);
 709         if (!function)
 710                 return NULL;
 711
 712         return function->name;
 713 }
 714 EXPORT_SYMBOL_GPL(pinmux_generic_get_function_name);
 715
 716 /**
 717  * pinmux_generic_get_function_groups() - gets the function groups
 718  * @pctldev: pin controller device
 719  * @selector: function number
 720  * @groups: array of pin groups
 721  * @num_groups: number of pin groups
 722  */
 723 int pinmux_generic_get_function_groups(struct pinctrl_dev *pctldev,
 724                                        unsigned int selector,
 725                                        const char * const **groups,
 726                                        unsigned * const num_groups)
 727 {
 728         struct function_desc *function;
 729
 730         function = radix_tree_lookup(&pctldev->pin_function_tree,
 731                                      selector);
 732         if (!function) {
 733                 dev_err(pctldev->dev, "%s could not find function%i\n",
 734                         __func__, selector);
 735                 return -EINVAL;
 736         }
 737         *groups = function->group_names;
 738         *num_groups = function->num_group_names;
 739
 740         return 0;
 741 }
 742 EXPORT_SYMBOL_GPL(pinmux_generic_get_function_groups);
 743
 744 /**
 745  * pinmux_generic_get_function() - returns a function based on the number
 746  * @pctldev: pin controller device
 747  * @group_selector: function number
 748  */
 749 struct function_desc *pinmux_generic_get_function(struct pinctrl_dev *pctldev,
 750                                                   unsigned int selector)
 751 {
 752         struct function_desc *function;
 753
 754         function = radix_tree_lookup(&pctldev->pin_function_tree,
 755                                      selector);
 756         if (!function)
 757                 return NULL;
 758
 759         return function;
 760 }
 761 EXPORT_SYMBOL_GPL(pinmux_generic_get_function);
 762
 763 /**
 764  * pinmux_generic_add_function() - adds a function group
 765  * @pctldev: pin controller device
 766  * @name: name of the function
 767  * @groups: array of pin groups
 768  * @num_groups: number of pin groups
 769  * @data: pin controller driver specific data
 770  */
 771 int pinmux_generic_add_function(struct pinctrl_dev *pctldev,
 772                                 const char *name,
 773                                 const char **groups,
 774                                 const unsigned int num_groups,
 775                                 void *data)
 776 {
 777         struct function_desc *function;
 778
 779         function = devm_kzalloc(pctldev->dev, sizeof(*function), GFP_KERNEL);
 780         if (!function)
 781                 return -ENOMEM;
 782
 783         function->name = name;
 784         function->group_names = groups;
 785         function->num_group_names = num_groups;
 786         function->data = data;
 787
 788         radix_tree_insert(&pctldev->pin_function_tree, pctldev->num_functions,
 789                           function);
 790
 791         pctldev->num_functions++;
 792
 793         return 0;
 794 }
 795 EXPORT_SYMBOL_GPL(pinmux_generic_add_function);
 796
 797 /**
 798  * pinmux_generic_remove_function() - removes a numbered function
 799  * @pctldev: pin controller device
 800  * @selector: function number
 801  *
 802  * Note that the caller must take care of locking.
 803  */
 804 int pinmux_generic_remove_function(struct pinctrl_dev *pctldev,
 805                                    unsigned int selector)
 806 {
 807         struct function_desc *function;
 808
 809         function = radix_tree_lookup(&pctldev->pin_function_tree,
 810                                      selector);
 811         if (!function)
 812                 return -ENOENT;
 813
 814         radix_tree_delete(&pctldev->pin_function_tree, selector);
 815         devm_kfree(pctldev->dev, function);
 816
 817         pctldev->num_functions--;
 818
 819         return 0;
 820 }
 821 EXPORT_SYMBOL_GPL(pinmux_generic_remove_function);
 822
 823 /**
 824  * pinmux_generic_free_functions() - removes all functions
 825  * @pctldev: pin controller device
 826  *
 827  * Note that the caller must take care of locking. The pinctrl
 828  * functions are allocated with devm_kzalloc() so no need to free
 829  * them here.
 830  */
 831 void pinmux_generic_free_functions(struct pinctrl_dev *pctldev)
 832 {
 833         struct radix_tree_iter iter;
 834         void __rcu **slot;
 835
 836         radix_tree_for_each_slot(slot, &pctldev->pin_function_tree, &iter, 0)
 837                 radix_tree_delete(&pctldev->pin_function_tree, iter.index);
 838
 839         pctldev->num_functions = 0;
 840 }
 841
 842 #endif /* CONFIG_GENERIC_PINMUX_FUNCTIONS */