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 #ifdef CONFIG_PINCTRL
  62 /**
  63  * acpi_gpiochip_pin_to_gpio_offset() - translates ACPI GPIO to Linux GPIO
  64  * @chip: GPIO chip
  65  * @pin: ACPI GPIO pin number from GpioIo/GpioInt resource
  66  *
  67  * Function takes ACPI GpioIo/GpioInt pin number as a parameter and
  68  * translates it to a corresponding offset suitable to be passed to a
  69  * GPIO controller driver.
  70  *
  71  * Typically the returned offset is same as @pin, but if the GPIO
  72  * controller uses pin controller and the mapping is not contiguous the
  73  * offset might be different.
  74  */
  75 static int acpi_gpiochip_pin_to_gpio_offset(struct gpio_device *gdev, int pin)
  76 {
  77         struct gpio_pin_range *pin_range;
  78
  79         /* If there are no ranges in this chip, use 1:1 mapping */
  80         if (list_empty(&gdev->pin_ranges))
  81                 return pin;
  82
  83         list_for_each_entry(pin_range, &gdev->pin_ranges, node) {
  84                 const struct pinctrl_gpio_range *range = &pin_range->range;
  85                 int i;
  86
  87                 if (range->pins) {
  88                         for (i = 0; i < range->npins; i++) {
  89                                 if (range->pins[i] == pin)
  90                                         return range->base + i - gdev->base;
  91                         }
  92                 } else {
  93                         if (pin >= range->pin_base &&
  94                             pin < range->pin_base + range->npins) {
  95                                 unsigned gpio_base;
  96
  97                                 gpio_base = range->base - gdev->base;
  98                                 return gpio_base + pin - range->pin_base;
  99                         }
 100                 }
 101         }
 102
 103         return -EINVAL;
 104 }
 105 #else
 106 static inline int acpi_gpiochip_pin_to_gpio_offset(struct gpio_device *gdev,
 107                                                    int pin)
 108 {
 109         return pin;
 110 }
 111 #endif
 112
 113 /**
 114  * acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API
 115  * @path:       ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
 116  * @pin:        ACPI GPIO pin number (0-based, controller-relative)
 117  *
 118  * Return: GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR
 119  * error value. Specifically returns %-EPROBE_DEFER if the referenced GPIO
 120  * controller does not have gpiochip registered at the moment. This is to
 121  * support probe deferral.
 122  */
 123 static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
 124 {
 125         struct gpio_chip *chip;
 126         acpi_handle handle;
 127         acpi_status status;
 128         int offset;
 129
 130         status = acpi_get_handle(NULL, path, &handle);
 131         if (ACPI_FAILURE(status))
 132                 return ERR_PTR(-ENODEV);
 133
 134         chip = gpiochip_find(handle, acpi_gpiochip_find);
 135         if (!chip)
 136                 return ERR_PTR(-EPROBE_DEFER);
 137
 138         offset = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, pin);
 139         if (offset < 0)
 140                 return ERR_PTR(offset);
 141
 142         return gpiochip_get_desc(chip, offset);
 143 }
 144
 145 static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
 146 {
 147         struct acpi_gpio_event *event = data;
 148
 149         acpi_evaluate_object(event->handle, NULL, NULL, NULL);
 150
 151         return IRQ_HANDLED;
 152 }
 153
 154 static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
 155 {
 156         struct acpi_gpio_event *event = data;
 157
 158         acpi_execute_simple_method(event->handle, NULL, event->pin);
 159
 160         return IRQ_HANDLED;
 161 }
 162
 163 static void acpi_gpio_chip_dh(acpi_handle handle, void *data)
 164 {
 165         /* The address of this function is used as a key. */
 166 }
 167
 168 static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
 169                                                    void *context)
 170 {
 171         struct acpi_gpio_chip *acpi_gpio = context;
 172         struct gpio_chip *chip = acpi_gpio->chip;
 173         struct acpi_resource_gpio *agpio;
 174         acpi_handle handle, evt_handle;
 175         struct acpi_gpio_event *event;
 176         irq_handler_t handler = NULL;
 177         struct gpio_desc *desc;
 178         unsigned long irqflags;
 179         int ret, pin, irq;
 180
 181         if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
 182                 return AE_OK;
 183
 184         agpio = &ares->data.gpio;
 185         if (agpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT)
 186                 return AE_OK;
 187
 188         handle = ACPI_HANDLE(chip->parent);
 189         pin = agpio->pin_table[0];
 190
 191         if (pin <= 255) {
 192                 char ev_name[5];
 193                 sprintf(ev_name, "_%c%02X",
 194                         agpio->triggering == ACPI_EDGE_SENSITIVE ? 'E' : 'L',
 195                         pin);
 196                 if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
 197                         handler = acpi_gpio_irq_handler;
 198         }
 199         if (!handler) {
 200                 if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
 201                         handler = acpi_gpio_irq_handler_evt;
 202         }
 203         if (!handler)
 204                 return AE_BAD_PARAMETER;
 205
 206         pin = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, pin);
 207         if (pin < 0)
 208                 return AE_BAD_PARAMETER;
 209
 210         desc = gpiochip_request_own_desc(chip, pin, "ACPI:Event");
 211         if (IS_ERR(desc)) {
 212                 dev_err(chip->parent, "Failed to request GPIO\n");
 213                 return AE_ERROR;
 214         }
 215
 216         gpiod_direction_input(desc);
 217
 218         ret = gpiochip_lock_as_irq(chip, pin);
 219         if (ret) {
 220                 dev_err(chip->parent, "Failed to lock GPIO as interrupt\n");
 221                 goto fail_free_desc;
 222         }
 223
 224         irq = gpiod_to_irq(desc);
 225         if (irq < 0) {
 226                 dev_err(chip->parent, "Failed to translate GPIO to IRQ\n");
 227                 goto fail_unlock_irq;
 228         }
 229
 230         irqflags = IRQF_ONESHOT;
 231         if (agpio->triggering == ACPI_LEVEL_SENSITIVE) {
 232                 if (agpio->polarity == ACPI_ACTIVE_HIGH)
 233                         irqflags |= IRQF_TRIGGER_HIGH;
 234                 else
 235                         irqflags |= IRQF_TRIGGER_LOW;
 236         } else {
 237                 switch (agpio->polarity) {
 238                 case ACPI_ACTIVE_HIGH:
 239                         irqflags |= IRQF_TRIGGER_RISING;
 240                         break;
 241                 case ACPI_ACTIVE_LOW:
 242                         irqflags |= IRQF_TRIGGER_FALLING;
 243                         break;
 244                 default:
 245                         irqflags |= IRQF_TRIGGER_RISING |
 246                                     IRQF_TRIGGER_FALLING;
 247                         break;
 248                 }
 249         }
 250
 251         event = kzalloc(sizeof(*event), GFP_KERNEL);
 252         if (!event)
 253                 goto fail_unlock_irq;
 254
 255         event->handle = evt_handle;
 256         event->irq = irq;
 257         event->pin = pin;
 258         event->desc = desc;
 259
 260         ret = request_threaded_irq(event->irq, NULL, handler, irqflags,
 261                                    "ACPI:Event", event);
 262         if (ret) {
 263                 dev_err(chip->parent,
 264                         "Failed to setup interrupt handler for %d\n",
 265                         event->irq);
 266                 goto fail_free_event;
 267         }
 268
 269         if (agpio->wake_capable == ACPI_WAKE_CAPABLE)
 270                 enable_irq_wake(irq);
 271
 272         list_add_tail(&event->node, &acpi_gpio->events);
 273         return AE_OK;
 274
 275 fail_free_event:
 276         kfree(event);
 277 fail_unlock_irq:
 278         gpiochip_unlock_as_irq(chip, pin);
 279 fail_free_desc:
 280         gpiochip_free_own_desc(desc);
 281
 282         return AE_ERROR;
 283 }
 284
 285 /**
 286  * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
 287  * @chip:      GPIO chip
 288  *
 289  * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
 290  * handled by ACPI event methods which need to be called from the GPIO
 291  * chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
 292  * gpio pins have acpi event methods and assigns interrupt handlers that calls
 293  * the acpi event methods for those pins.
 294  */
 295 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
 296 {
 297         struct acpi_gpio_chip *acpi_gpio;
 298         acpi_handle handle;
 299         acpi_status status;
 300
 301         if (!chip->parent || !chip->to_irq)
 302                 return;
 303
 304         handle = ACPI_HANDLE(chip->parent);
 305         if (!handle)
 306                 return;
 307
 308         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 309         if (ACPI_FAILURE(status))
 310                 return;
 311
 312         acpi_walk_resources(handle, "_AEI",
 313                             acpi_gpiochip_request_interrupt, acpi_gpio);
 314 }
 315 EXPORT_SYMBOL_GPL(acpi_gpiochip_request_interrupts);
 316
 317 /**
 318  * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
 319  * @chip:      GPIO chip
 320  *
 321  * Free interrupts associated with GPIO ACPI event method for the given
 322  * GPIO chip.
 323  */
 324 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
 325 {
 326         struct acpi_gpio_chip *acpi_gpio;
 327         struct acpi_gpio_event *event, *ep;
 328         acpi_handle handle;
 329         acpi_status status;
 330
 331         if (!chip->parent || !chip->to_irq)
 332                 return;
 333
 334         handle = ACPI_HANDLE(chip->parent);
 335         if (!handle)
 336                 return;
 337
 338         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 339         if (ACPI_FAILURE(status))
 340                 return;
 341
 342         list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
 343                 struct gpio_desc *desc;
 344
 345                 if (irqd_is_wakeup_set(irq_get_irq_data(event->irq)))
 346                         disable_irq_wake(event->irq);
 347
 348                 free_irq(event->irq, event);
 349                 desc = event->desc;
 350                 if (WARN_ON(IS_ERR(desc)))
 351                         continue;
 352                 gpiochip_unlock_as_irq(chip, event->pin);
 353                 gpiochip_free_own_desc(desc);
 354                 list_del(&event->node);
 355                 kfree(event);
 356         }
 357 }
 358 EXPORT_SYMBOL_GPL(acpi_gpiochip_free_interrupts);
 359
 360 int acpi_dev_add_driver_gpios(struct acpi_device *adev,
 361                               const struct acpi_gpio_mapping *gpios)
 362 {
 363         if (adev && gpios) {
 364                 adev->driver_gpios = gpios;
 365                 return 0;
 366         }
 367         return -EINVAL;
 368 }
 369 EXPORT_SYMBOL_GPL(acpi_dev_add_driver_gpios);
 370
 371 static void devm_acpi_dev_release_driver_gpios(struct device *dev, void *res)
 372 {
 373         acpi_dev_remove_driver_gpios(ACPI_COMPANION(dev));
 374 }
 375
 376 int devm_acpi_dev_add_driver_gpios(struct device *dev,
 377                                    const struct acpi_gpio_mapping *gpios)
 378 {
 379         void *res;
 380         int ret;
 381
 382         res = devres_alloc(devm_acpi_dev_release_driver_gpios, 0, GFP_KERNEL);
 383         if (!res)
 384                 return -ENOMEM;
 385
 386         ret = acpi_dev_add_driver_gpios(ACPI_COMPANION(dev), gpios);
 387         if (ret) {
 388                 devres_free(res);
 389                 return ret;
 390         }
 391         devres_add(dev, res);
 392         return 0;
 393 }
 394 EXPORT_SYMBOL_GPL(devm_acpi_dev_add_driver_gpios);
 395
 396 void devm_acpi_dev_remove_driver_gpios(struct device *dev)
 397 {
 398         WARN_ON(devres_release(dev, devm_acpi_dev_release_driver_gpios, NULL, NULL));
 399 }
 400 EXPORT_SYMBOL_GPL(devm_acpi_dev_remove_driver_gpios);
 401
 402 static bool acpi_get_driver_gpio_data(struct acpi_device *adev,
 403                                       const char *name, int index,
 404                                       struct acpi_reference_args *args)
 405 {
 406         const struct acpi_gpio_mapping *gm;
 407
 408         if (!adev->driver_gpios)
 409                 return false;
 410
 411         for (gm = adev->driver_gpios; gm->name; gm++)
 412                 if (!strcmp(name, gm->name) && gm->data && index < gm->size) {
 413                         const struct acpi_gpio_params *par = gm->data + index;
 414
 415                         args->adev = adev;
 416                         args->args[0] = par->crs_entry_index;
 417                         args->args[1] = par->line_index;
 418                         args->args[2] = par->active_low;
 419                         args->nargs = 3;
 420                         return true;
 421                 }
 422
 423         return false;
 424 }
 425
 426 struct acpi_gpio_lookup {
 427         struct acpi_gpio_info info;
 428         int index;
 429         int pin_index;
 430         bool active_low;
 431         struct acpi_device *adev;
 432         struct gpio_desc *desc;
 433         int n;
 434 };
 435
 436 static int acpi_populate_gpio_lookup(struct acpi_resource *ares, void *data)
 437 {
 438         struct acpi_gpio_lookup *lookup = data;
 439
 440         if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
 441                 return 1;
 442
 443         if (lookup->n++ == lookup->index && !lookup->desc) {
 444                 const struct acpi_resource_gpio *agpio = &ares->data.gpio;
 445                 int pin_index = lookup->pin_index;
 446
 447                 if (pin_index >= agpio->pin_table_length)
 448                         return 1;
 449
 450                 lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
 451                                               agpio->pin_table[pin_index]);
 452                 lookup->info.gpioint =
 453                         agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
 454
 455                 /*
 456                  * Polarity and triggering are only specified for GpioInt
 457                  * resource.
 458                  * Note: we expect here:
 459                  * - ACPI_ACTIVE_LOW == GPIO_ACTIVE_LOW
 460                  * - ACPI_ACTIVE_HIGH == GPIO_ACTIVE_HIGH
 461                  */
 462                 if (lookup->info.gpioint) {
 463                         lookup->info.polarity = agpio->polarity;
 464                         lookup->info.triggering = agpio->triggering;
 465                 }
 466
 467         }
 468
 469         return 1;
 470 }
 471
 472 static int acpi_gpio_resource_lookup(struct acpi_gpio_lookup *lookup,
 473                                      struct acpi_gpio_info *info)
 474 {
 475         struct list_head res_list;
 476         int ret;
 477
 478         INIT_LIST_HEAD(&res_list);
 479
 480         ret = acpi_dev_get_resources(lookup->adev, &res_list,
 481                                      acpi_populate_gpio_lookup,
 482                                      lookup);
 483         if (ret < 0)
 484                 return ret;
 485
 486         acpi_dev_free_resource_list(&res_list);
 487
 488         if (!lookup->desc)
 489                 return -ENOENT;
 490
 491         if (info) {
 492                 *info = lookup->info;
 493                 if (lookup->active_low)
 494                         info->polarity = lookup->active_low;
 495         }
 496         return 0;
 497 }
 498
 499 static int acpi_gpio_property_lookup(struct fwnode_handle *fwnode,
 500                                      const char *propname, int index,
 501                                      struct acpi_gpio_lookup *lookup)
 502 {
 503         struct acpi_reference_args args;
 504         int ret;
 505
 506         memset(&args, 0, sizeof(args));
 507         ret = __acpi_node_get_property_reference(fwnode, propname, index, 3,
 508                                                  &args);
 509         if (ret) {
 510                 struct acpi_device *adev = to_acpi_device_node(fwnode);
 511
 512                 if (!adev)
 513                         return ret;
 514
 515                 if (!acpi_get_driver_gpio_data(adev, propname, index, &args))
 516                         return ret;
 517         }
 518         /*
 519          * The property was found and resolved, so need to lookup the GPIO based
 520          * on returned args.
 521          */
 522         lookup->adev = args.adev;
 523         if (args.nargs != 3)
 524                 return -EPROTO;
 525
 526         lookup->index = args.args[0];
 527         lookup->pin_index = args.args[1];
 528         lookup->active_low = !!args.args[2];
 529
 530         return 0;
 531 }
 532
 533 /**
 534  * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
 535  * @adev: pointer to a ACPI device to get GPIO from
 536  * @propname: Property name of the GPIO (optional)
 537  * @index: index of GpioIo/GpioInt resource (starting from %0)
 538  * @info: info pointer to fill in (optional)
 539  *
 540  * Function goes through ACPI resources for @adev and based on @index looks
 541  * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
 542  * and returns it. @index matches GpioIo/GpioInt resources only so if there
 543  * are total %3 GPIO resources, the index goes from %0 to %2.
 544  *
 545  * If @propname is specified the GPIO is looked using device property. In
 546  * that case @index is used to select the GPIO entry in the property value
 547  * (in case of multiple).
 548  *
 549  * If the GPIO cannot be translated or there is an error an ERR_PTR is
 550  * returned.
 551  *
 552  * Note: if the GPIO resource has multiple entries in the pin list, this
 553  * function only returns the first.
 554  */
 555 static struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
 556                                           const char *propname, int index,
 557                                           struct acpi_gpio_info *info)
 558 {
 559         struct acpi_gpio_lookup lookup;
 560         int ret;
 561
 562         if (!adev)
 563                 return ERR_PTR(-ENODEV);
 564
 565         memset(&lookup, 0, sizeof(lookup));
 566         lookup.index = index;
 567
 568         if (propname) {
 569                 dev_dbg(&adev->dev, "GPIO: looking up %s\n", propname);
 570
 571                 ret = acpi_gpio_property_lookup(acpi_fwnode_handle(adev),
 572                                                 propname, index, &lookup);
 573                 if (ret)
 574                         return ERR_PTR(ret);
 575
 576                 dev_dbg(&adev->dev, "GPIO: _DSD returned %s %d %d %u\n",
 577                         dev_name(&lookup.adev->dev), lookup.index,
 578                         lookup.pin_index, lookup.active_low);
 579         } else {
 580                 dev_dbg(&adev->dev, "GPIO: looking up %d in _CRS\n", index);
 581                 lookup.adev = adev;
 582         }
 583
 584         ret = acpi_gpio_resource_lookup(&lookup, info);
 585         return ret ? ERR_PTR(ret) : lookup.desc;
 586 }
 587
 588 struct gpio_desc *acpi_find_gpio(struct device *dev,
 589                                  const char *con_id,
 590                                  unsigned int idx,
 591                                  enum gpiod_flags flags,
 592                                  enum gpio_lookup_flags *lookupflags)
 593 {
 594         struct acpi_device *adev = ACPI_COMPANION(dev);
 595         struct acpi_gpio_info info;
 596         struct gpio_desc *desc;
 597         char propname[32];
 598         int i;
 599
 600         /* Try first from _DSD */
 601         for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
 602                 if (con_id && strcmp(con_id, "gpios")) {
 603                         snprintf(propname, sizeof(propname), "%s-%s",
 604                                  con_id, gpio_suffixes[i]);
 605                 } else {
 606                         snprintf(propname, sizeof(propname), "%s",
 607                                  gpio_suffixes[i]);
 608                 }
 609
 610                 desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
 611                 if (!IS_ERR(desc))
 612                         break;
 613                 if (PTR_ERR(desc) == -EPROBE_DEFER)
 614                         return ERR_CAST(desc);
 615         }
 616
 617         /* Then from plain _CRS GPIOs */
 618         if (IS_ERR(desc)) {
 619                 if (!acpi_can_fallback_to_crs(adev, con_id))
 620                         return ERR_PTR(-ENOENT);
 621
 622                 desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
 623                 if (IS_ERR(desc))
 624                         return desc;
 625
 626                 if ((flags == GPIOD_OUT_LOW || flags == GPIOD_OUT_HIGH) &&
 627                     info.gpioint) {
 628                         dev_dbg(dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
 629                         return ERR_PTR(-ENOENT);
 630                 }
 631         }
 632
 633         if (info.polarity == GPIO_ACTIVE_LOW)
 634                 *lookupflags |= GPIO_ACTIVE_LOW;
 635
 636         return desc;
 637 }
 638
 639 /**
 640  * acpi_node_get_gpiod() - get a GPIO descriptor from ACPI resources
 641  * @fwnode: pointer to an ACPI firmware node to get the GPIO information from
 642  * @propname: Property name of the GPIO
 643  * @index: index of GpioIo/GpioInt resource (starting from %0)
 644  * @info: info pointer to fill in (optional)
 645  *
 646  * If @fwnode is an ACPI device object, call %acpi_get_gpiod_by_index() for it.
 647  * Otherwise (ie. it is a data-only non-device object), use the property-based
 648  * GPIO lookup to get to the GPIO resource with the relevant information and use
 649  * that to obtain the GPIO descriptor to return.
 650  */
 651 struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
 652                                       const char *propname, int index,
 653                                       struct acpi_gpio_info *info)
 654 {
 655         struct acpi_gpio_lookup lookup;
 656         struct acpi_device *adev;
 657         int ret;
 658
 659         adev = to_acpi_device_node(fwnode);
 660         if (adev)
 661                 return acpi_get_gpiod_by_index(adev, propname, index, info);
 662
 663         if (!is_acpi_data_node(fwnode))
 664                 return ERR_PTR(-ENODEV);
 665
 666         if (!propname)
 667                 return ERR_PTR(-EINVAL);
 668
 669         memset(&lookup, 0, sizeof(lookup));
 670         lookup.index = index;
 671
 672         ret = acpi_gpio_property_lookup(fwnode, propname, index, &lookup);
 673         if (ret)
 674                 return ERR_PTR(ret);
 675
 676         ret = acpi_gpio_resource_lookup(&lookup, info);
 677         return ret ? ERR_PTR(ret) : lookup.desc;
 678 }
 679
 680 /**
 681  * acpi_dev_gpio_irq_get() - Find GpioInt and translate it to Linux IRQ number
 682  * @adev: pointer to a ACPI device to get IRQ from
 683  * @index: index of GpioInt resource (starting from %0)
 684  *
 685  * If the device has one or more GpioInt resources, this function can be
 686  * used to translate from the GPIO offset in the resource to the Linux IRQ
 687  * number.
 688  *
 689  * Return: Linux IRQ number (>%0) on success, negative errno on failure.
 690  */
 691 int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
 692 {
 693         int idx, i;
 694         unsigned int irq_flags;
 695
 696         for (i = 0, idx = 0; idx <= index; i++) {
 697                 struct acpi_gpio_info info;
 698                 struct gpio_desc *desc;
 699
 700                 desc = acpi_get_gpiod_by_index(adev, NULL, i, &info);
 701
 702                 /* Ignore -EPROBE_DEFER, it only matters if idx matches */
 703                 if (IS_ERR(desc) && PTR_ERR(desc) != -EPROBE_DEFER)
 704                         return PTR_ERR(desc);
 705
 706                 if (info.gpioint && idx++ == index) {
 707                         int irq;
 708
 709                         if (IS_ERR(desc))
 710                                 return PTR_ERR(desc);
 711
 712                         irq = gpiod_to_irq(desc);
 713                         if (irq < 0)
 714                                 return irq;
 715
 716                         irq_flags = acpi_dev_get_irq_type(info.triggering,
 717                                                           info.polarity);
 718
 719                         /* Set type if specified and different than the current one */
 720                         if (irq_flags != IRQ_TYPE_NONE &&
 721                             irq_flags != irq_get_trigger_type(irq))
 722                                 irq_set_irq_type(irq, irq_flags);
 723
 724                         return irq;
 725                 }
 726
 727         }
 728         return -ENOENT;
 729 }
 730 EXPORT_SYMBOL_GPL(acpi_dev_gpio_irq_get);
 731
 732 static acpi_status
 733 acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
 734                             u32 bits, u64 *value, void *handler_context,
 735                             void *region_context)
 736 {
 737         struct acpi_gpio_chip *achip = region_context;
 738         struct gpio_chip *chip = achip->chip;
 739         struct acpi_resource_gpio *agpio;
 740         struct acpi_resource *ares;
 741         int pin_index = (int)address;
 742         acpi_status status;
 743         bool pull_up;
 744         int length;
 745         int i;
 746
 747         status = acpi_buffer_to_resource(achip->conn_info.connection,
 748                                          achip->conn_info.length, &ares);
 749         if (ACPI_FAILURE(status))
 750                 return status;
 751
 752         if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) {
 753                 ACPI_FREE(ares);
 754                 return AE_BAD_PARAMETER;
 755         }
 756
 757         agpio = &ares->data.gpio;
 758         pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP;
 759
 760         if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT &&
 761             function == ACPI_WRITE)) {
 762                 ACPI_FREE(ares);
 763                 return AE_BAD_PARAMETER;
 764         }
 765
 766         length = min(agpio->pin_table_length, (u16)(pin_index + bits));
 767         for (i = pin_index; i < length; ++i) {
 768                 int pin = agpio->pin_table[i];
 769                 struct acpi_gpio_connection *conn;
 770                 struct gpio_desc *desc;
 771                 bool found;
 772
 773                 pin = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, pin);
 774                 if (pin < 0) {
 775                         status = AE_BAD_PARAMETER;
 776                         goto out;
 777                 }
 778
 779                 mutex_lock(&achip->conn_lock);
 780
 781                 found = false;
 782                 list_for_each_entry(conn, &achip->conns, node) {
 783                         if (conn->pin == pin) {
 784                                 found = true;
 785                                 desc = conn->desc;
 786                                 break;
 787                         }
 788                 }
 789
 790                 /*
 791                  * The same GPIO can be shared between operation region and
 792                  * event but only if the access here is ACPI_READ. In that
 793                  * case we "borrow" the event GPIO instead.
 794                  */
 795                 if (!found && agpio->sharable == ACPI_SHARED &&
 796                      function == ACPI_READ) {
 797                         struct acpi_gpio_event *event;
 798
 799                         list_for_each_entry(event, &achip->events, node) {
 800                                 if (event->pin == pin) {
 801                                         desc = event->desc;
 802                                         found = true;
 803                                         break;
 804                                 }
 805                         }
 806                 }
 807
 808                 if (!found) {
 809                         desc = gpiochip_request_own_desc(chip, pin,
 810                                                          "ACPI:OpRegion");
 811                         if (IS_ERR(desc)) {
 812                                 status = AE_ERROR;
 813                                 mutex_unlock(&achip->conn_lock);
 814                                 goto out;
 815                         }
 816
 817                         switch (agpio->io_restriction) {
 818                         case ACPI_IO_RESTRICT_INPUT:
 819                                 gpiod_direction_input(desc);
 820                                 break;
 821                         case ACPI_IO_RESTRICT_OUTPUT:
 822                                 /*
 823                                  * ACPI GPIO resources don't contain an
 824                                  * initial value for the GPIO. Therefore we
 825                                  * deduce that value from the pull field
 826                                  * instead. If the pin is pulled up we
 827                                  * assume default to be high, otherwise
 828                                  * low.
 829                                  */
 830                                 gpiod_direction_output(desc, pull_up);
 831                                 break;
 832                         default:
 833                                 /*
 834                                  * Assume that the BIOS has configured the
 835                                  * direction and pull accordingly.
 836                                  */
 837                                 break;
 838                         }
 839
 840                         conn = kzalloc(sizeof(*conn), GFP_KERNEL);
 841                         if (!conn) {
 842                                 status = AE_NO_MEMORY;
 843                                 gpiochip_free_own_desc(desc);
 844                                 mutex_unlock(&achip->conn_lock);
 845                                 goto out;
 846                         }
 847
 848                         conn->pin = pin;
 849                         conn->desc = desc;
 850                         list_add_tail(&conn->node, &achip->conns);
 851                 }
 852
 853                 mutex_unlock(&achip->conn_lock);
 854
 855                 if (function == ACPI_WRITE)
 856                         gpiod_set_raw_value_cansleep(desc,
 857                                                      !!((1 << i) & *value));
 858                 else
 859                         *value |= (u64)gpiod_get_raw_value_cansleep(desc) << i;
 860         }
 861
 862 out:
 863         ACPI_FREE(ares);
 864         return status;
 865 }
 866
 867 static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip)
 868 {
 869         struct gpio_chip *chip = achip->chip;
 870         acpi_handle handle = ACPI_HANDLE(chip->parent);
 871         acpi_status status;
 872
 873         INIT_LIST_HEAD(&achip->conns);
 874         mutex_init(&achip->conn_lock);
 875         status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
 876                                                     acpi_gpio_adr_space_handler,
 877                                                     NULL, achip);
 878         if (ACPI_FAILURE(status))
 879                 dev_err(chip->parent,
 880                         "Failed to install GPIO OpRegion handler\n");
 881 }
 882
 883 static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
 884 {
 885         struct gpio_chip *chip = achip->chip;
 886         acpi_handle handle = ACPI_HANDLE(chip->parent);
 887         struct acpi_gpio_connection *conn, *tmp;
 888         acpi_status status;
 889
 890         status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
 891                                                    acpi_gpio_adr_space_handler);
 892         if (ACPI_FAILURE(status)) {
 893                 dev_err(chip->parent,
 894                         "Failed to remove GPIO OpRegion handler\n");
 895                 return;
 896         }
 897
 898         list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) {
 899                 gpiochip_free_own_desc(conn->desc);
 900                 list_del(&conn->node);
 901                 kfree(conn);
 902         }
 903 }
 904
 905 static struct gpio_desc *acpi_gpiochip_parse_own_gpio(
 906         struct acpi_gpio_chip *achip, struct fwnode_handle *fwnode,
 907         const char **name, unsigned int *lflags, unsigned int *dflags)
 908 {
 909         struct gpio_chip *chip = achip->chip;
 910         struct gpio_desc *desc;
 911         u32 gpios[2];
 912         int ret;
 913
 914         *lflags = 0;
 915         *dflags = 0;
 916         *name = NULL;
 917
 918         ret = fwnode_property_read_u32_array(fwnode, "gpios", gpios,
 919                                              ARRAY_SIZE(gpios));
 920         if (ret < 0)
 921                 return ERR_PTR(ret);
 922
 923         ret = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, gpios[0]);
 924         if (ret < 0)
 925                 return ERR_PTR(ret);
 926
 927         desc = gpiochip_get_desc(chip, ret);
 928         if (IS_ERR(desc))
 929                 return desc;
 930
 931         if (gpios[1])
 932                 *lflags |= GPIO_ACTIVE_LOW;
 933
 934         if (fwnode_property_present(fwnode, "input"))
 935                 *dflags |= GPIOD_IN;
 936         else if (fwnode_property_present(fwnode, "output-low"))
 937                 *dflags |= GPIOD_OUT_LOW;
 938         else if (fwnode_property_present(fwnode, "output-high"))
 939                 *dflags |= GPIOD_OUT_HIGH;
 940         else
 941                 return ERR_PTR(-EINVAL);
 942
 943         fwnode_property_read_string(fwnode, "line-name", name);
 944
 945         return desc;
 946 }
 947
 948 static void acpi_gpiochip_scan_gpios(struct acpi_gpio_chip *achip)
 949 {
 950         struct gpio_chip *chip = achip->chip;
 951         struct fwnode_handle *fwnode;
 952
 953         device_for_each_child_node(chip->parent, fwnode) {
 954                 unsigned int lflags, dflags;
 955                 struct gpio_desc *desc;
 956                 const char *name;
 957                 int ret;
 958
 959                 if (!fwnode_property_present(fwnode, "gpio-hog"))
 960                         continue;
 961
 962                 desc = acpi_gpiochip_parse_own_gpio(achip, fwnode, &name,
 963                                                     &lflags, &dflags);
 964                 if (IS_ERR(desc))
 965                         continue;
 966
 967                 ret = gpiod_hog(desc, name, lflags, dflags);
 968                 if (ret) {
 969                         dev_err(chip->parent, "Failed to hog GPIO\n");
 970                         fwnode_handle_put(fwnode);
 971                         return;
 972                 }
 973         }
 974 }
 975
 976 void acpi_gpiochip_add(struct gpio_chip *chip)
 977 {
 978         struct acpi_gpio_chip *acpi_gpio;
 979         acpi_handle handle;
 980         acpi_status status;
 981
 982         if (!chip || !chip->parent)
 983                 return;
 984
 985         handle = ACPI_HANDLE(chip->parent);
 986         if (!handle)
 987                 return;
 988
 989         acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
 990         if (!acpi_gpio) {
 991                 dev_err(chip->parent,
 992                         "Failed to allocate memory for ACPI GPIO chip\n");
 993                 return;
 994         }
 995
 996         acpi_gpio->chip = chip;
 997         INIT_LIST_HEAD(&acpi_gpio->events);
 998
 999         status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
1000         if (ACPI_FAILURE(status)) {
1001                 dev_err(chip->parent, "Failed to attach ACPI GPIO chip\n");
1002                 kfree(acpi_gpio);
1003                 return;
1004         }
1005
1006         if (!chip->names)
1007                 devprop_gpiochip_set_names(chip);
1008
1009         acpi_gpiochip_request_regions(acpi_gpio);
1010         acpi_gpiochip_scan_gpios(acpi_gpio);
1011         acpi_walk_dep_device_list(handle);
1012 }
1013
1014 void acpi_gpiochip_remove(struct gpio_chip *chip)
1015 {
1016         struct acpi_gpio_chip *acpi_gpio;
1017         acpi_handle handle;
1018         acpi_status status;
1019
1020         if (!chip || !chip->parent)
1021                 return;
1022
1023         handle = ACPI_HANDLE(chip->parent);
1024         if (!handle)
1025                 return;
1026
1027         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
1028         if (ACPI_FAILURE(status)) {
1029                 dev_warn(chip->parent, "Failed to retrieve ACPI GPIO chip\n");
1030                 return;
1031         }
1032
1033         acpi_gpiochip_free_regions(acpi_gpio);
1034
1035         acpi_detach_data(handle, acpi_gpio_chip_dh);
1036         kfree(acpi_gpio);
1037 }
1038
1039 static int acpi_gpio_package_count(const union acpi_object *obj)
1040 {
1041         const union acpi_object *element = obj->package.elements;
1042         const union acpi_object *end = element + obj->package.count;
1043         unsigned int count = 0;
1044
1045         while (element < end) {
1046                 switch (element->type) {
1047                 case ACPI_TYPE_LOCAL_REFERENCE:
1048                         element += 3;
1049                         /* Fallthrough */
1050                 case ACPI_TYPE_INTEGER:
1051                         element++;
1052                         count++;
1053                         break;
1054
1055                 default:
1056                         return -EPROTO;
1057                 }
1058         }
1059
1060         return count;
1061 }
1062
1063 static int acpi_find_gpio_count(struct acpi_resource *ares, void *data)
1064 {
1065         unsigned int *count = data;
1066
1067         if (ares->type == ACPI_RESOURCE_TYPE_GPIO)
1068                 *count += ares->data.gpio.pin_table_length;
1069
1070         return 1;
1071 }
1072
1073 /**
1074  * acpi_gpio_count - return the number of GPIOs associated with a
1075  *              device / function or -ENOENT if no GPIO has been
1076  *              assigned to the requested function.
1077  * @dev:        GPIO consumer, can be NULL for system-global GPIOs
1078  * @con_id:     function within the GPIO consumer
1079  */
1080 int acpi_gpio_count(struct device *dev, const char *con_id)
1081 {
1082         struct acpi_device *adev = ACPI_COMPANION(dev);
1083         const union acpi_object *obj;
1084         const struct acpi_gpio_mapping *gm;
1085         int count = -ENOENT;
1086         int ret;
1087         char propname[32];
1088         unsigned int i;
1089
1090         /* Try first from _DSD */
1091         for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1092                 if (con_id && strcmp(con_id, "gpios"))
1093                         snprintf(propname, sizeof(propname), "%s-%s",
1094                                  con_id, gpio_suffixes[i]);
1095                 else
1096                         snprintf(propname, sizeof(propname), "%s",
1097                                  gpio_suffixes[i]);
1098
1099                 ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY,
1100                                             &obj);
1101                 if (ret == 0) {
1102                         if (obj->type == ACPI_TYPE_LOCAL_REFERENCE)
1103                                 count = 1;
1104                         else if (obj->type == ACPI_TYPE_PACKAGE)
1105                                 count = acpi_gpio_package_count(obj);
1106                 } else if (adev->driver_gpios) {
1107                         for (gm = adev->driver_gpios; gm->name; gm++)
1108                                 if (strcmp(propname, gm->name) == 0) {
1109                                         count = gm->size;
1110                                         break;
1111                                 }
1112                 }
1113                 if (count > 0)
1114                         break;
1115         }
1116
1117         /* Then from plain _CRS GPIOs */
1118         if (count < 0) {
1119                 struct list_head resource_list;
1120                 unsigned int crs_count = 0;
1121
1122                 INIT_LIST_HEAD(&resource_list);
1123                 acpi_dev_get_resources(adev, &resource_list,
1124                                        acpi_find_gpio_count, &crs_count);
1125                 acpi_dev_free_resource_list(&resource_list);
1126                 if (crs_count > 0)
1127                         count = crs_count;
1128         }
1129         return count ? count : -ENOENT;
1130 }
1131
1132 struct acpi_crs_lookup {
1133         struct list_head node;
1134         struct acpi_device *adev;
1135         const char *con_id;
1136 };
1137
1138 static DEFINE_MUTEX(acpi_crs_lookup_lock);
1139 static LIST_HEAD(acpi_crs_lookup_list);
1140
1141 bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id)
1142 {
1143         struct acpi_crs_lookup *l, *lookup = NULL;
1144
1145         /* Never allow fallback if the device has properties */
1146         if (adev->data.properties || adev->driver_gpios)
1147                 return false;
1148
1149         mutex_lock(&acpi_crs_lookup_lock);
1150
1151         list_for_each_entry(l, &acpi_crs_lookup_list, node) {
1152                 if (l->adev == adev) {
1153                         lookup = l;
1154                         break;
1155                 }
1156         }
1157
1158         if (!lookup) {
1159                 lookup = kmalloc(sizeof(*lookup), GFP_KERNEL);
1160                 if (lookup) {
1161                         lookup->adev = adev;
1162                         lookup->con_id = kstrdup(con_id, GFP_KERNEL);
1163                         list_add_tail(&lookup->node, &acpi_crs_lookup_list);
1164                 }
1165         }
1166
1167         mutex_unlock(&acpi_crs_lookup_lock);
1168
1169         return lookup &&
1170                 ((!lookup->con_id && !con_id) ||
1171                  (lookup->con_id && con_id &&
1172                   strcmp(lookup->con_id, con_id) == 0));
1173 }