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