drivers/gpio/gpiolib-acpi.c

   1 /*
   2  * ACPI helpers for GPIO API
   3  *
   4  * Copyright (C) 2012, Intel Corporation
   5  * Authors: Mathias Nyman <mathias.nyman@linux.intel.com>
   6  *          Mika Westerberg <mika.westerberg@linux.intel.com>
   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
  13 #include <linux/errno.h>
  14 #include <linux/gpio.h>
  15 #include <linux/gpio/consumer.h>
  16 #include <linux/gpio/driver.h>
  17 #include <linux/gpio/machine.h>
  18 #include <linux/export.h>
  19 #include <linux/acpi.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/mutex.h>
  22 #include <linux/pinctrl/pinctrl.h>
  23
  24 #include "gpiolib.h"
  25
  26 struct acpi_gpio_event {
  27         struct list_head node;
  28         acpi_handle handle;
  29         unsigned int pin;
  30         unsigned int irq;
  31         struct gpio_desc *desc;
  32 };
  33
  34 struct acpi_gpio_connection {
  35         struct list_head node;
  36         unsigned int pin;
  37         struct gpio_desc *desc;
  38 };
  39
  40 struct acpi_gpio_chip {
  41         /*
  42          * ACPICA requires that the first field of the context parameter
  43          * passed to acpi_install_address_space_handler() is large enough
  44          * to hold struct acpi_connection_info.
  45          */
  46         struct acpi_connection_info conn_info;
  47         struct list_head conns;
  48         struct mutex conn_lock;
  49         struct gpio_chip *chip;
  50         struct list_head events;
  51 };
  52
  53 static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
  54 {
  55         if (!gc->parent)
  56                 return false;
  57
  58         return ACPI_HANDLE(gc->parent) == data;
  59 }
  60
  61 /**
  62  * acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API
  63  * @path:       ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
  64  * @pin:        ACPI GPIO pin number (0-based, controller-relative)
  65  *
  66  * Return: GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR
  67  * error value. Specifically returns %-EPROBE_DEFER if the referenced GPIO
  68  * controller does not have gpiochip registered at the moment. This is to
  69  * support probe deferral.
  70  */
  71 static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
  72 {
  73         struct gpio_chip *chip;
  74         acpi_handle handle;
  75         acpi_status status;
  76
  77         status = acpi_get_handle(NULL, path, &handle);
  78         if (ACPI_FAILURE(status))
  79                 return ERR_PTR(-ENODEV);
  80
  81         chip = gpiochip_find(handle, acpi_gpiochip_find);
  82         if (!chip)
  83                 return ERR_PTR(-EPROBE_DEFER);
  84
  85         return gpiochip_get_desc(chip, pin);
  86 }
  87
  88 static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
  89 {
  90         struct acpi_gpio_event *event = data;
  91
  92         acpi_evaluate_object(event->handle, NULL, NULL, NULL);
  93
  94         return IRQ_HANDLED;
  95 }
  96
  97 static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
  98 {
  99         struct acpi_gpio_event *event = data;
 100
 101         acpi_execute_simple_method(event->handle, NULL, event->pin);
 102
 103         return IRQ_HANDLED;
 104 }
 105
 106 static void acpi_gpio_chip_dh(acpi_handle handle, void *data)
 107 {
 108         /* The address of this function is used as a key. */
 109 }
 110
 111 bool acpi_gpio_get_irq_resource(struct acpi_resource *ares,
 112                                 struct acpi_resource_gpio **agpio)
 113 {
 114         struct acpi_resource_gpio *gpio;
 115
 116         if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
 117                 return false;
 118
 119         gpio = &ares->data.gpio;
 120         if (gpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT)
 121                 return false;
 122
 123         *agpio = gpio;
 124         return true;
 125 }
 126 EXPORT_SYMBOL_GPL(acpi_gpio_get_irq_resource);
 127
 128 static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
 129                                                    void *context)
 130 {
 131         struct acpi_gpio_chip *acpi_gpio = context;
 132         struct gpio_chip *chip = acpi_gpio->chip;
 133         struct acpi_resource_gpio *agpio;
 134         acpi_handle handle, evt_handle;
 135         struct acpi_gpio_event *event;
 136         irq_handler_t handler = NULL;
 137         struct gpio_desc *desc;
 138         unsigned long irqflags;
 139         int ret, pin, irq;
 140
 141         if (!acpi_gpio_get_irq_resource(ares, &agpio))
 142                 return AE_OK;
 143
 144         handle = ACPI_HANDLE(chip->parent);
 145         pin = agpio->pin_table[0];
 146
 147         if (pin <= 255) {
 148                 char ev_name[5];
 149                 sprintf(ev_name, "_%c%02hhX",
 150                         agpio->triggering == ACPI_EDGE_SENSITIVE ? 'E' : 'L',
 151                         pin);
 152                 if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
 153                         handler = acpi_gpio_irq_handler;
 154         }
 155         if (!handler) {
 156                 if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
 157                         handler = acpi_gpio_irq_handler_evt;
 158         }
 159         if (!handler)
 160                 return AE_OK;
 161
 162         desc = gpiochip_request_own_desc(chip, pin, "ACPI:Event");
 163         if (IS_ERR(desc)) {
 164                 dev_err(chip->parent, "Failed to request GPIO\n");
 165                 return AE_ERROR;
 166         }
 167
 168         gpiod_direction_input(desc);
 169
 170         ret = gpiochip_lock_as_irq(chip, pin);
 171         if (ret) {
 172                 dev_err(chip->parent, "Failed to lock GPIO as interrupt\n");
 173                 goto fail_free_desc;
 174         }
 175
 176         irq = gpiod_to_irq(desc);
 177         if (irq < 0) {
 178                 dev_err(chip->parent, "Failed to translate GPIO to IRQ\n");
 179                 goto fail_unlock_irq;
 180         }
 181
 182         irqflags = IRQF_ONESHOT;
 183         if (agpio->triggering == ACPI_LEVEL_SENSITIVE) {
 184                 if (agpio->polarity == ACPI_ACTIVE_HIGH)
 185                         irqflags |= IRQF_TRIGGER_HIGH;
 186                 else
 187                         irqflags |= IRQF_TRIGGER_LOW;
 188         } else {
 189                 switch (agpio->polarity) {
 190                 case ACPI_ACTIVE_HIGH:
 191                         irqflags |= IRQF_TRIGGER_RISING;
 192                         break;
 193                 case ACPI_ACTIVE_LOW:
 194                         irqflags |= IRQF_TRIGGER_FALLING;
 195                         break;
 196                 default:
 197                         irqflags |= IRQF_TRIGGER_RISING |
 198                                     IRQF_TRIGGER_FALLING;
 199                         break;
 200                 }
 201         }
 202
 203         event = kzalloc(sizeof(*event), GFP_KERNEL);
 204         if (!event)
 205                 goto fail_unlock_irq;
 206
 207         event->handle = evt_handle;
 208         event->irq = irq;
 209         event->pin = pin;
 210         event->desc = desc;
 211
 212         ret = request_threaded_irq(event->irq, NULL, handler, irqflags,
 213                                    "ACPI:Event", event);
 214         if (ret) {
 215                 dev_err(chip->parent,
 216                         "Failed to setup interrupt handler for %d\n",
 217                         event->irq);
 218                 goto fail_free_event;
 219         }
 220
 221         if (agpio->wake_capable == ACPI_WAKE_CAPABLE)
 222                 enable_irq_wake(irq);
 223
 224         list_add_tail(&event->node, &acpi_gpio->events);
 225         return AE_OK;
 226
 227 fail_free_event:
 228         kfree(event);
 229 fail_unlock_irq:
 230         gpiochip_unlock_as_irq(chip, pin);
 231 fail_free_desc:
 232         gpiochip_free_own_desc(desc);
 233
 234         return AE_ERROR;
 235 }
 236
 237 /**
 238  * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
 239  * @chip:      GPIO chip
 240  *
 241  * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
 242  * handled by ACPI event methods which need to be called from the GPIO
 243  * chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
 244  * gpio pins have acpi event methods and assigns interrupt handlers that calls
 245  * the acpi event methods for those pins.
 246  */
 247 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
 248 {
 249         struct acpi_gpio_chip *acpi_gpio;
 250         acpi_handle handle;
 251         acpi_status status;
 252
 253         if (!chip->parent || !chip->to_irq)
 254                 return;
 255
 256         handle = ACPI_HANDLE(chip->parent);
 257         if (!handle)
 258                 return;
 259
 260         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 261         if (ACPI_FAILURE(status))
 262                 return;
 263
 264         acpi_walk_resources(handle, "_AEI",
 265                             acpi_gpiochip_request_interrupt, acpi_gpio);
 266 }
 267 EXPORT_SYMBOL_GPL(acpi_gpiochip_request_interrupts);
 268
 269 /**
 270  * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
 271  * @chip:      GPIO chip
 272  *
 273  * Free interrupts associated with GPIO ACPI event method for the given
 274  * GPIO chip.
 275  */
 276 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
 277 {
 278         struct acpi_gpio_chip *acpi_gpio;
 279         struct acpi_gpio_event *event, *ep;
 280         acpi_handle handle;
 281         acpi_status status;
 282
 283         if (!chip->parent || !chip->to_irq)
 284                 return;
 285
 286         handle = ACPI_HANDLE(chip->parent);
 287         if (!handle)
 288                 return;
 289
 290         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 291         if (ACPI_FAILURE(status))
 292                 return;
 293
 294         list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
 295                 struct gpio_desc *desc;
 296
 297                 if (irqd_is_wakeup_set(irq_get_irq_data(event->irq)))
 298                         disable_irq_wake(event->irq);
 299
 300                 free_irq(event->irq, event);
 301                 desc = event->desc;
 302                 if (WARN_ON(IS_ERR(desc)))
 303                         continue;
 304                 gpiochip_unlock_as_irq(chip, event->pin);
 305                 gpiochip_free_own_desc(desc);
 306                 list_del(&event->node);
 307                 kfree(event);
 308         }
 309 }
 310 EXPORT_SYMBOL_GPL(acpi_gpiochip_free_interrupts);
 311
 312 int acpi_dev_add_driver_gpios(struct acpi_device *adev,
 313                               const struct acpi_gpio_mapping *gpios)
 314 {
 315         if (adev && gpios) {
 316                 adev->driver_gpios = gpios;
 317                 return 0;
 318         }
 319         return -EINVAL;
 320 }
 321 EXPORT_SYMBOL_GPL(acpi_dev_add_driver_gpios);
 322
 323 static void devm_acpi_dev_release_driver_gpios(struct device *dev, void *res)
 324 {
 325         acpi_dev_remove_driver_gpios(ACPI_COMPANION(dev));
 326 }
 327
 328 int devm_acpi_dev_add_driver_gpios(struct device *dev,
 329                                    const struct acpi_gpio_mapping *gpios)
 330 {
 331         void *res;
 332         int ret;
 333
 334         res = devres_alloc(devm_acpi_dev_release_driver_gpios, 0, GFP_KERNEL);
 335         if (!res)
 336                 return -ENOMEM;
 337
 338         ret = acpi_dev_add_driver_gpios(ACPI_COMPANION(dev), gpios);
 339         if (ret) {
 340                 devres_free(res);
 341                 return ret;
 342         }
 343         devres_add(dev, res);
 344         return 0;
 345 }
 346 EXPORT_SYMBOL_GPL(devm_acpi_dev_add_driver_gpios);
 347
 348 void devm_acpi_dev_remove_driver_gpios(struct device *dev)
 349 {
 350         WARN_ON(devres_release(dev, devm_acpi_dev_release_driver_gpios, NULL, NULL));
 351 }
 352 EXPORT_SYMBOL_GPL(devm_acpi_dev_remove_driver_gpios);
 353
 354 static bool acpi_get_driver_gpio_data(struct acpi_device *adev,
 355                                       const char *name, int index,
 356                                       struct acpi_reference_args *args)
 357 {
 358         const struct acpi_gpio_mapping *gm;
 359
 360         if (!adev->driver_gpios)
 361                 return false;
 362
 363         for (gm = adev->driver_gpios; gm->name; gm++)
 364                 if (!strcmp(name, gm->name) && gm->data && index < gm->size) {
 365                         const struct acpi_gpio_params *par = gm->data + index;
 366
 367                         args->adev = adev;
 368                         args->args[0] = par->crs_entry_index;
 369                         args->args[1] = par->line_index;
 370                         args->args[2] = par->active_low;
 371                         args->nargs = 3;
 372                         return true;
 373                 }
 374
 375         return false;
 376 }
 377
 378 static enum gpiod_flags
 379 acpi_gpio_to_gpiod_flags(const struct acpi_resource_gpio *agpio)
 380 {
 381         bool pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP;
 382
 383         switch (agpio->io_restriction) {
 384         case ACPI_IO_RESTRICT_INPUT:
 385                 return GPIOD_IN;
 386         case ACPI_IO_RESTRICT_OUTPUT:
 387                 /*
 388                  * ACPI GPIO resources don't contain an initial value for the
 389                  * GPIO. Therefore we deduce that value from the pull field
 390                  * instead. If the pin is pulled up we assume default to be
 391                  * high, otherwise low.
 392                  */
 393                 return pull_up ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
 394         default:
 395                 /*
 396                  * Assume that the BIOS has configured the direction and pull
 397                  * accordingly.
 398                  */
 399                 return GPIOD_ASIS;
 400         }
 401 }
 402
 403 int
 404 acpi_gpio_update_gpiod_flags(enum gpiod_flags *flags, enum gpiod_flags update)
 405 {
 406         int ret = 0;
 407
 408         /*
 409          * Check if the BIOS has IoRestriction with explicitly set direction
 410          * and update @flags accordingly. Otherwise use whatever caller asked
 411          * for.
 412          */
 413         if (update & GPIOD_FLAGS_BIT_DIR_SET) {
 414                 enum gpiod_flags diff = *flags ^ update;
 415
 416                 /*
 417                  * Check if caller supplied incompatible GPIO initialization
 418                  * flags.
 419                  *
 420                  * Return %-EINVAL to notify that firmware has different
 421                  * settings and we are going to use them.
 422                  */
 423                 if (((*flags & GPIOD_FLAGS_BIT_DIR_SET) && (diff & GPIOD_FLAGS_BIT_DIR_OUT)) ||
 424                     ((*flags & GPIOD_FLAGS_BIT_DIR_OUT) && (diff & GPIOD_FLAGS_BIT_DIR_VAL)))
 425                         ret = -EINVAL;
 426                 *flags = update;
 427         }
 428         return ret;
 429 }
 430
 431 struct acpi_gpio_lookup {
 432         struct acpi_gpio_info info;
 433         int index;
 434         int pin_index;
 435         bool active_low;
 436         struct acpi_device *adev;
 437         struct gpio_desc *desc;
 438         int n;
 439 };
 440
 441 static int acpi_populate_gpio_lookup(struct acpi_resource *ares, void *data)
 442 {
 443         struct acpi_gpio_lookup *lookup = data;
 444
 445         if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
 446                 return 1;
 447
 448         if (lookup->n++ == lookup->index && !lookup->desc) {
 449                 const struct acpi_resource_gpio *agpio = &ares->data.gpio;
 450                 int pin_index = lookup->pin_index;
 451
 452                 if (pin_index >= agpio->pin_table_length)
 453                         return 1;
 454
 455                 lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
 456                                               agpio->pin_table[pin_index]);
 457                 lookup->info.gpioint =
 458                         agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
 459
 460                 /*
 461                  * Polarity and triggering are only specified for GpioInt
 462                  * resource.
 463                  * Note: we expect here:
 464                  * - ACPI_ACTIVE_LOW == GPIO_ACTIVE_LOW
 465                  * - ACPI_ACTIVE_HIGH == GPIO_ACTIVE_HIGH
 466                  */
 467                 if (lookup->info.gpioint) {
 468                         lookup->info.flags = GPIOD_IN;
 469                         lookup->info.polarity = agpio->polarity;
 470                         lookup->info.triggering = agpio->triggering;
 471                 } else {
 472                         lookup->info.flags = acpi_gpio_to_gpiod_flags(agpio);
 473                 }
 474
 475         }
 476
 477         return 1;
 478 }
 479
 480 static int acpi_gpio_resource_lookup(struct acpi_gpio_lookup *lookup,
 481                                      struct acpi_gpio_info *info)
 482 {
 483         struct list_head res_list;
 484         int ret;
 485
 486         INIT_LIST_HEAD(&res_list);
 487
 488         ret = acpi_dev_get_resources(lookup->adev, &res_list,
 489                                      acpi_populate_gpio_lookup,
 490                                      lookup);
 491         if (ret < 0)
 492                 return ret;
 493
 494         acpi_dev_free_resource_list(&res_list);
 495
 496         if (!lookup->desc)
 497                 return -ENOENT;
 498
 499         if (info) {
 500                 *info = lookup->info;
 501                 if (lookup->active_low)
 502                         info->polarity = lookup->active_low;
 503         }
 504         return 0;
 505 }
 506
 507 static int acpi_gpio_property_lookup(struct fwnode_handle *fwnode,
 508                                      const char *propname, int index,
 509                                      struct acpi_gpio_lookup *lookup)
 510 {
 511         struct acpi_reference_args args;
 512         int ret;
 513
 514         memset(&args, 0, sizeof(args));
 515         ret = __acpi_node_get_property_reference(fwnode, propname, index, 3,
 516                                                  &args);
 517         if (ret) {
 518                 struct acpi_device *adev = to_acpi_device_node(fwnode);
 519
 520                 if (!adev)
 521                         return ret;
 522
 523                 if (!acpi_get_driver_gpio_data(adev, propname, index, &args))
 524                         return ret;
 525         }
 526         /*
 527          * The property was found and resolved, so need to lookup the GPIO based
 528          * on returned args.
 529          */
 530         lookup->adev = args.adev;
 531         if (args.nargs != 3)
 532                 return -EPROTO;
 533
 534         lookup->index = args.args[0];
 535         lookup->pin_index = args.args[1];
 536         lookup->active_low = !!args.args[2];
 537
 538         return 0;
 539 }
 540
 541 /**
 542  * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
 543  * @adev: pointer to a ACPI device to get GPIO from
 544  * @propname: Property name of the GPIO (optional)
 545  * @index: index of GpioIo/GpioInt resource (starting from %0)
 546  * @info: info pointer to fill in (optional)
 547  *
 548  * Function goes through ACPI resources for @adev and based on @index looks
 549  * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
 550  * and returns it. @index matches GpioIo/GpioInt resources only so if there
 551  * are total %3 GPIO resources, the index goes from %0 to %2.
 552  *
 553  * If @propname is specified the GPIO is looked using device property. In
 554  * that case @index is used to select the GPIO entry in the property value
 555  * (in case of multiple).
 556  *
 557  * If the GPIO cannot be translated or there is an error an ERR_PTR is
 558  * returned.
 559  *
 560  * Note: if the GPIO resource has multiple entries in the pin list, this
 561  * function only returns the first.
 562  */
 563 static struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
 564                                           const char *propname, int index,
 565                                           struct acpi_gpio_info *info)
 566 {
 567         struct acpi_gpio_lookup lookup;
 568         int ret;
 569
 570         if (!adev)
 571                 return ERR_PTR(-ENODEV);
 572
 573         memset(&lookup, 0, sizeof(lookup));
 574         lookup.index = index;
 575
 576         if (propname) {
 577                 dev_dbg(&adev->dev, "GPIO: looking up %s\n", propname);
 578
 579                 ret = acpi_gpio_property_lookup(acpi_fwnode_handle(adev),
 580                                                 propname, index, &lookup);
 581                 if (ret)
 582                         return ERR_PTR(ret);
 583
 584                 dev_dbg(&adev->dev, "GPIO: _DSD returned %s %d %d %u\n",
 585                         dev_name(&lookup.adev->dev), lookup.index,
 586                         lookup.pin_index, lookup.active_low);
 587         } else {
 588                 dev_dbg(&adev->dev, "GPIO: looking up %d in _CRS\n", index);
 589                 lookup.adev = adev;
 590         }
 591
 592         ret = acpi_gpio_resource_lookup(&lookup, info);
 593         return ret ? ERR_PTR(ret) : lookup.desc;
 594 }
 595
 596 struct gpio_desc *acpi_find_gpio(struct device *dev,
 597                                  const char *con_id,
 598                                  unsigned int idx,
 599                                  enum gpiod_flags *dflags,
 600                                  enum gpio_lookup_flags *lookupflags)
 601 {
 602         struct acpi_device *adev = ACPI_COMPANION(dev);
 603         struct acpi_gpio_info info;
 604         struct gpio_desc *desc;
 605         char propname[32];
 606         int err;
 607         int i;
 608
 609         /* Try first from _DSD */
 610         for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
 611                 if (con_id) {
 612                         snprintf(propname, sizeof(propname), "%s-%s",
 613                                  con_id, gpio_suffixes[i]);
 614                 } else {
 615                         snprintf(propname, sizeof(propname), "%s",
 616                                  gpio_suffixes[i]);
 617                 }
 618
 619                 desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
 620                 if (!IS_ERR(desc))
 621                         break;
 622                 if (PTR_ERR(desc) == -EPROBE_DEFER)
 623                         return ERR_CAST(desc);
 624         }
 625
 626         /* Then from plain _CRS GPIOs */
 627         if (IS_ERR(desc)) {
 628                 if (!acpi_can_fallback_to_crs(adev, con_id))
 629                         return ERR_PTR(-ENOENT);
 630
 631                 desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
 632                 if (IS_ERR(desc))
 633                         return desc;
 634         }
 635
 636         if (info.gpioint &&
 637             (*dflags == GPIOD_OUT_LOW || *dflags == GPIOD_OUT_HIGH)) {
 638                 dev_dbg(dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
 639                 return ERR_PTR(-ENOENT);
 640         }
 641
 642         if (info.polarity == GPIO_ACTIVE_LOW)
 643                 *lookupflags |= GPIO_ACTIVE_LOW;
 644
 645         err = acpi_gpio_update_gpiod_flags(dflags, info.flags);
 646         if (err)
 647                 dev_dbg(dev, "Override GPIO initialization flags\n");
 648
 649         return desc;
 650 }
 651
 652 /**
 653  * acpi_node_get_gpiod() - get a GPIO descriptor from ACPI resources
 654  * @fwnode: pointer to an ACPI firmware node to get the GPIO information from
 655  * @propname: Property name of the GPIO
 656  * @index: index of GpioIo/GpioInt resource (starting from %0)
 657  * @info: info pointer to fill in (optional)
 658  *
 659  * If @fwnode is an ACPI device object, call %acpi_get_gpiod_by_index() for it.
 660  * Otherwise (ie. it is a data-only non-device object), use the property-based
 661  * GPIO lookup to get to the GPIO resource with the relevant information and use
 662  * that to obtain the GPIO descriptor to return.
 663  */
 664 struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
 665                                       const char *propname, int index,
 666                                       struct acpi_gpio_info *info)
 667 {
 668         struct acpi_gpio_lookup lookup;
 669         struct acpi_device *adev;
 670         int ret;
 671
 672         adev = to_acpi_device_node(fwnode);
 673         if (adev)
 674                 return acpi_get_gpiod_by_index(adev, propname, index, info);
 675
 676         if (!is_acpi_data_node(fwnode))
 677                 return ERR_PTR(-ENODEV);
 678
 679         if (!propname)
 680                 return ERR_PTR(-EINVAL);
 681
 682         memset(&lookup, 0, sizeof(lookup));
 683         lookup.index = index;
 684
 685         ret = acpi_gpio_property_lookup(fwnode, propname, index, &lookup);
 686         if (ret)
 687                 return ERR_PTR(ret);
 688
 689         ret = acpi_gpio_resource_lookup(&lookup, info);
 690         return ret ? ERR_PTR(ret) : lookup.desc;
 691 }
 692
 693 /**
 694  * acpi_dev_gpio_irq_get() - Find GpioInt and translate it to Linux IRQ number
 695  * @adev: pointer to a ACPI device to get IRQ from
 696  * @index: index of GpioInt resource (starting from %0)
 697  *
 698  * If the device has one or more GpioInt resources, this function can be
 699  * used to translate from the GPIO offset in the resource to the Linux IRQ
 700  * number.
 701  *
 702  * The function is idempotent, though each time it runs it will configure GPIO
 703  * pin direction according to the flags in GpioInt resource.
 704  *
 705  * Return: Linux IRQ number (> %0) on success, negative errno on failure.
 706  */
 707 int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
 708 {
 709         int idx, i;
 710         unsigned int irq_flags;
 711         int ret;
 712
 713         for (i = 0, idx = 0; idx <= index; i++) {
 714                 struct acpi_gpio_info info;
 715                 struct gpio_desc *desc;
 716
 717                 desc = acpi_get_gpiod_by_index(adev, NULL, i, &info);
 718
 719                 /* Ignore -EPROBE_DEFER, it only matters if idx matches */
 720                 if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER)
 721                         return PTR_ERR(desc);
 722
 723                 if (info.gpioint && idx++ == index) {
 724                         char label[32];
 725                         int irq;
 726
 727                         if (IS_ERR(desc))
 728                                 return PTR_ERR(desc);
 729
 730                         irq = gpiod_to_irq(desc);
 731                         if (irq < 0)
 732                                 return irq;
 733
 734                         snprintf(label, sizeof(label), "GpioInt() %d", index);
 735                         ret = gpiod_configure_flags(desc, label, 0, info.flags);
 736                         if (ret < 0)
 737                                 return ret;
 738
 739                         irq_flags = acpi_dev_get_irq_type(info.triggering,
 740                                                           info.polarity);
 741
 742                         /* Set type if specified and different than the current one */
 743                         if (irq_flags != IRQ_TYPE_NONE &&
 744                             irq_flags != irq_get_trigger_type(irq))
 745                                 irq_set_irq_type(irq, irq_flags);
 746
 747                         return irq;
 748                 }
 749
 750         }
 751         return -ENOENT;
 752 }
 753 EXPORT_SYMBOL_GPL(acpi_dev_gpio_irq_get);
 754
 755 static acpi_status
 756 acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
 757                             u32 bits, u64 *value, void *handler_context,
 758                             void *region_context)
 759 {
 760         struct acpi_gpio_chip *achip = region_context;
 761         struct gpio_chip *chip = achip->chip;
 762         struct acpi_resource_gpio *agpio;
 763         struct acpi_resource *ares;
 764         int pin_index = (int)address;
 765         acpi_status status;
 766         int length;
 767         int i;
 768
 769         status = acpi_buffer_to_resource(achip->conn_info.connection,
 770                                          achip->conn_info.length, &ares);
 771         if (ACPI_FAILURE(status))
 772                 return status;
 773
 774         if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) {
 775                 ACPI_FREE(ares);
 776                 return AE_BAD_PARAMETER;
 777         }
 778
 779         agpio = &ares->data.gpio;
 780
 781         if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT &&
 782             function == ACPI_WRITE)) {
 783                 ACPI_FREE(ares);
 784                 return AE_BAD_PARAMETER;
 785         }
 786
 787         length = min(agpio->pin_table_length, (u16)(pin_index + bits));
 788         for (i = pin_index; i < length; ++i) {
 789                 int pin = agpio->pin_table[i];
 790                 struct acpi_gpio_connection *conn;
 791                 struct gpio_desc *desc;
 792                 bool found;
 793
 794                 mutex_lock(&achip->conn_lock);
 795
 796                 found = false;
 797                 list_for_each_entry(conn, &achip->conns, node) {
 798                         if (conn->pin == pin) {
 799                                 found = true;
 800                                 desc = conn->desc;
 801                                 break;
 802                         }
 803                 }
 804
 805                 /*
 806                  * The same GPIO can be shared between operation region and
 807                  * event but only if the access here is ACPI_READ. In that
 808                  * case we "borrow" the event GPIO instead.
 809                  */
 810                 if (!found && agpio->sharable == ACPI_SHARED &&
 811                      function == ACPI_READ) {
 812                         struct acpi_gpio_event *event;
 813
 814                         list_for_each_entry(event, &achip->events, node) {
 815                                 if (event->pin == pin) {
 816                                         desc = event->desc;
 817                                         found = true;
 818                                         break;
 819                                 }
 820                         }
 821                 }
 822
 823                 if (!found) {
 824                         enum gpiod_flags flags = acpi_gpio_to_gpiod_flags(agpio);
 825                         const char *label = "ACPI:OpRegion";
 826                         int err;
 827
 828                         desc = gpiochip_request_own_desc(chip, pin, label);
 829                         if (IS_ERR(desc)) {
 830                                 status = AE_ERROR;
 831                                 mutex_unlock(&achip->conn_lock);
 832                                 goto out;
 833                         }
 834
 835                         err = gpiod_configure_flags(desc, label, 0, flags);
 836                         if (err < 0) {
 837                                 status = AE_NOT_CONFIGURED;
 838                                 gpiochip_free_own_desc(desc);
 839                                 mutex_unlock(&achip->conn_lock);
 840                                 goto out;
 841                         }
 842
 843                         conn = kzalloc(sizeof(*conn), GFP_KERNEL);
 844                         if (!conn) {
 845                                 status = AE_NO_MEMORY;
 846                                 gpiochip_free_own_desc(desc);
 847                                 mutex_unlock(&achip->conn_lock);
 848                                 goto out;
 849                         }
 850
 851                         conn->pin = pin;
 852                         conn->desc = desc;
 853                         list_add_tail(&conn->node, &achip->conns);
 854                 }
 855
 856                 mutex_unlock(&achip->conn_lock);
 857
 858                 if (function == ACPI_WRITE)
 859                         gpiod_set_raw_value_cansleep(desc,
 860                                                      !!((1 << i) & *value));
 861                 else
 862                         *value |= (u64)gpiod_get_raw_value_cansleep(desc) << i;
 863         }
 864
 865 out:
 866         ACPI_FREE(ares);
 867         return status;
 868 }
 869
 870 static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip)
 871 {
 872         struct gpio_chip *chip = achip->chip;
 873         acpi_handle handle = ACPI_HANDLE(chip->parent);
 874         acpi_status status;
 875
 876         INIT_LIST_HEAD(&achip->conns);
 877         mutex_init(&achip->conn_lock);
 878         status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
 879                                                     acpi_gpio_adr_space_handler,
 880                                                     NULL, achip);
 881         if (ACPI_FAILURE(status))
 882                 dev_err(chip->parent,
 883                         "Failed to install GPIO OpRegion handler\n");
 884 }
 885
 886 static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
 887 {
 888         struct gpio_chip *chip = achip->chip;
 889         acpi_handle handle = ACPI_HANDLE(chip->parent);
 890         struct acpi_gpio_connection *conn, *tmp;
 891         acpi_status status;
 892
 893         status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
 894                                                    acpi_gpio_adr_space_handler);
 895         if (ACPI_FAILURE(status)) {
 896                 dev_err(chip->parent,
 897                         "Failed to remove GPIO OpRegion handler\n");
 898                 return;
 899         }
 900
 901         list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) {
 902                 gpiochip_free_own_desc(conn->desc);
 903                 list_del(&conn->node);
 904                 kfree(conn);
 905         }
 906 }
 907
 908 static struct gpio_desc *acpi_gpiochip_parse_own_gpio(
 909         struct acpi_gpio_chip *achip, struct fwnode_handle *fwnode,
 910         const char **name, unsigned int *lflags, unsigned int *dflags)
 911 {
 912         struct gpio_chip *chip = achip->chip;
 913         struct gpio_desc *desc;
 914         u32 gpios[2];
 915         int ret;
 916
 917         *lflags = 0;
 918         *dflags = 0;
 919         *name = NULL;
 920
 921         ret = fwnode_property_read_u32_array(fwnode, "gpios", gpios,
 922                                              ARRAY_SIZE(gpios));
 923         if (ret < 0)
 924                 return ERR_PTR(ret);
 925
 926         desc = gpiochip_get_desc(chip, gpios[0]);
 927         if (IS_ERR(desc))
 928                 return desc;
 929
 930         if (gpios[1])
 931                 *lflags |= GPIO_ACTIVE_LOW;
 932
 933         if (fwnode_property_present(fwnode, "input"))
 934                 *dflags |= GPIOD_IN;
 935         else if (fwnode_property_present(fwnode, "output-low"))
 936                 *dflags |= GPIOD_OUT_LOW;
 937         else if (fwnode_property_present(fwnode, "output-high"))
 938                 *dflags |= GPIOD_OUT_HIGH;
 939         else
 940                 return ERR_PTR(-EINVAL);
 941
 942         fwnode_property_read_string(fwnode, "line-name", name);
 943
 944         return desc;
 945 }
 946
 947 static void acpi_gpiochip_scan_gpios(struct acpi_gpio_chip *achip)
 948 {
 949         struct gpio_chip *chip = achip->chip;
 950         struct fwnode_handle *fwnode;
 951
 952         device_for_each_child_node(chip->parent, fwnode) {
 953                 unsigned int lflags, dflags;
 954                 struct gpio_desc *desc;
 955                 const char *name;
 956                 int ret;
 957
 958                 if (!fwnode_property_present(fwnode, "gpio-hog"))
 959                         continue;
 960
 961                 desc = acpi_gpiochip_parse_own_gpio(achip, fwnode, &name,
 962                                                     &lflags, &dflags);
 963                 if (IS_ERR(desc))
 964                         continue;
 965
 966                 ret = gpiod_hog(desc, name, lflags, dflags);
 967                 if (ret) {
 968                         dev_err(chip->parent, "Failed to hog GPIO\n");
 969                         fwnode_handle_put(fwnode);
 970                         return;
 971                 }
 972         }
 973 }
 974
 975 void acpi_gpiochip_add(struct gpio_chip *chip)
 976 {
 977         struct acpi_gpio_chip *acpi_gpio;
 978         acpi_handle handle;
 979         acpi_status status;
 980
 981         if (!chip || !chip->parent)
 982                 return;
 983
 984         handle = ACPI_HANDLE(chip->parent);
 985         if (!handle)
 986                 return;
 987
 988         acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
 989         if (!acpi_gpio) {
 990                 dev_err(chip->parent,
 991                         "Failed to allocate memory for ACPI GPIO chip\n");
 992                 return;
 993         }
 994
 995         acpi_gpio->chip = chip;
 996         INIT_LIST_HEAD(&acpi_gpio->events);
 997
 998         status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
 999         if (ACPI_FAILURE(status)) {
1000                 dev_err(chip->parent, "Failed to attach ACPI GPIO chip\n");
1001                 kfree(acpi_gpio);
1002                 return;
1003         }
1004
1005         if (!chip->names)
1006                 devprop_gpiochip_set_names(chip, dev_fwnode(chip->parent));
1007
1008         acpi_gpiochip_request_regions(acpi_gpio);
1009         acpi_gpiochip_scan_gpios(acpi_gpio);
1010         acpi_walk_dep_device_list(handle);
1011 }
1012
1013 void acpi_gpiochip_remove(struct gpio_chip *chip)
1014 {
1015         struct acpi_gpio_chip *acpi_gpio;
1016         acpi_handle handle;
1017         acpi_status status;
1018
1019         if (!chip || !chip->parent)
1020                 return;
1021
1022         handle = ACPI_HANDLE(chip->parent);
1023         if (!handle)
1024                 return;
1025
1026         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
1027         if (ACPI_FAILURE(status)) {
1028                 dev_warn(chip->parent, "Failed to retrieve ACPI GPIO chip\n");
1029                 return;
1030         }
1031
1032         acpi_gpiochip_free_regions(acpi_gpio);
1033
1034         acpi_detach_data(handle, acpi_gpio_chip_dh);
1035         kfree(acpi_gpio);
1036 }
1037
1038 static int acpi_gpio_package_count(const union acpi_object *obj)
1039 {
1040         const union acpi_object *element = obj->package.elements;
1041         const union acpi_object *end = element + obj->package.count;
1042         unsigned int count = 0;
1043
1044         while (element < end) {
1045                 switch (element->type) {
1046                 case ACPI_TYPE_LOCAL_REFERENCE:
1047                         element += 3;
1048                         /* Fallthrough */
1049                 case ACPI_TYPE_INTEGER:
1050                         element++;
1051                         count++;
1052                         break;
1053
1054                 default:
1055                         return -EPROTO;
1056                 }
1057         }
1058
1059         return count;
1060 }
1061
1062 static int acpi_find_gpio_count(struct acpi_resource *ares, void *data)
1063 {
1064         unsigned int *count = data;
1065
1066         if (ares->type == ACPI_RESOURCE_TYPE_GPIO)
1067                 *count += ares->data.gpio.pin_table_length;
1068
1069         return 1;
1070 }
1071
1072 /**
1073  * acpi_gpio_count - return the number of GPIOs associated with a
1074  *              device / function or -ENOENT if no GPIO has been
1075  *              assigned to the requested function.
1076  * @dev:        GPIO consumer, can be NULL for system-global GPIOs
1077  * @con_id:     function within the GPIO consumer
1078  */
1079 int acpi_gpio_count(struct device *dev, const char *con_id)
1080 {
1081         struct acpi_device *adev = ACPI_COMPANION(dev);
1082         const union acpi_object *obj;
1083         const struct acpi_gpio_mapping *gm;
1084         int count = -ENOENT;
1085         int ret;
1086         char propname[32];
1087         unsigned int i;
1088
1089         /* Try first from _DSD */
1090         for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1091                 if (con_id)
1092                         snprintf(propname, sizeof(propname), "%s-%s",
1093                                  con_id, gpio_suffixes[i]);
1094                 else
1095                         snprintf(propname, sizeof(propname), "%s",
1096                                  gpio_suffixes[i]);
1097
1098                 ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY,
1099                                             &obj);
1100                 if (ret == 0) {
1101                         if (obj->type == ACPI_TYPE_LOCAL_REFERENCE)
1102                                 count = 1;
1103                         else if (obj->type == ACPI_TYPE_PACKAGE)
1104                                 count = acpi_gpio_package_count(obj);
1105                 } else if (adev->driver_gpios) {
1106                         for (gm = adev->driver_gpios; gm->name; gm++)
1107                                 if (strcmp(propname, gm->name) == 0) {
1108                                         count = gm->size;
1109                                         break;
1110                                 }
1111                 }
1112                 if (count > 0)
1113                         break;
1114         }
1115
1116         /* Then from plain _CRS GPIOs */
1117         if (count < 0) {
1118                 struct list_head resource_list;
1119                 unsigned int crs_count = 0;
1120
1121                 if (!acpi_can_fallback_to_crs(adev, con_id))
1122                         return count;
1123
1124                 INIT_LIST_HEAD(&resource_list);
1125                 acpi_dev_get_resources(adev, &resource_list,
1126                                        acpi_find_gpio_count, &crs_count);
1127                 acpi_dev_free_resource_list(&resource_list);
1128                 if (crs_count > 0)
1129                         count = crs_count;
1130         }
1131         return count ? count : -ENOENT;
1132 }
1133
1134 bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id)
1135 {
1136         /* Never allow fallback if the device has properties */
1137         if (acpi_dev_has_props(adev) || adev->driver_gpios)
1138                 return false;
1139
1140         return con_id == NULL;
1141 }