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         list_add_tail(&event->node, &acpi_gpio->events);
 270         return AE_OK;
 271
 272 fail_free_event:
 273         kfree(event);
 274 fail_unlock_irq:
 275         gpiochip_unlock_as_irq(chip, pin);
 276 fail_free_desc:
 277         gpiochip_free_own_desc(desc);
 278
 279         return AE_ERROR;
 280 }
 281
 282 /**
 283  * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
 284  * @chip:      GPIO chip
 285  *
 286  * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
 287  * handled by ACPI event methods which need to be called from the GPIO
 288  * chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
 289  * gpio pins have acpi event methods and assigns interrupt handlers that calls
 290  * the acpi event methods for those pins.
 291  */
 292 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
 293 {
 294         struct acpi_gpio_chip *acpi_gpio;
 295         acpi_handle handle;
 296         acpi_status status;
 297
 298         if (!chip->parent || !chip->to_irq)
 299                 return;
 300
 301         handle = ACPI_HANDLE(chip->parent);
 302         if (!handle)
 303                 return;
 304
 305         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 306         if (ACPI_FAILURE(status))
 307                 return;
 308
 309         acpi_walk_resources(handle, "_AEI",
 310                             acpi_gpiochip_request_interrupt, acpi_gpio);
 311 }
 312 EXPORT_SYMBOL_GPL(acpi_gpiochip_request_interrupts);
 313
 314 /**
 315  * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
 316  * @chip:      GPIO chip
 317  *
 318  * Free interrupts associated with GPIO ACPI event method for the given
 319  * GPIO chip.
 320  */
 321 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
 322 {
 323         struct acpi_gpio_chip *acpi_gpio;
 324         struct acpi_gpio_event *event, *ep;
 325         acpi_handle handle;
 326         acpi_status status;
 327
 328         if (!chip->parent || !chip->to_irq)
 329                 return;
 330
 331         handle = ACPI_HANDLE(chip->parent);
 332         if (!handle)
 333                 return;
 334
 335         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 336         if (ACPI_FAILURE(status))
 337                 return;
 338
 339         list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
 340                 struct gpio_desc *desc;
 341
 342                 free_irq(event->irq, event);
 343                 desc = event->desc;
 344                 if (WARN_ON(IS_ERR(desc)))
 345                         continue;
 346                 gpiochip_unlock_as_irq(chip, event->pin);
 347                 gpiochip_free_own_desc(desc);
 348                 list_del(&event->node);
 349                 kfree(event);
 350         }
 351 }
 352 EXPORT_SYMBOL_GPL(acpi_gpiochip_free_interrupts);
 353
 354 int acpi_dev_add_driver_gpios(struct acpi_device *adev,
 355                               const struct acpi_gpio_mapping *gpios)
 356 {
 357         if (adev && gpios) {
 358                 adev->driver_gpios = gpios;
 359                 return 0;
 360         }
 361         return -EINVAL;
 362 }
 363 EXPORT_SYMBOL_GPL(acpi_dev_add_driver_gpios);
 364
 365 static bool acpi_get_driver_gpio_data(struct acpi_device *adev,
 366                                       const char *name, int index,
 367                                       struct acpi_reference_args *args)
 368 {
 369         const struct acpi_gpio_mapping *gm;
 370
 371         if (!adev->driver_gpios)
 372                 return false;
 373
 374         for (gm = adev->driver_gpios; gm->name; gm++)
 375                 if (!strcmp(name, gm->name) && gm->data && index < gm->size) {
 376                         const struct acpi_gpio_params *par = gm->data + index;
 377
 378                         args->adev = adev;
 379                         args->args[0] = par->crs_entry_index;
 380                         args->args[1] = par->line_index;
 381                         args->args[2] = par->active_low;
 382                         args->nargs = 3;
 383                         return true;
 384                 }
 385
 386         return false;
 387 }
 388
 389 struct acpi_gpio_lookup {
 390         struct acpi_gpio_info info;
 391         int index;
 392         int pin_index;
 393         bool active_low;
 394         struct acpi_device *adev;
 395         struct gpio_desc *desc;
 396         int n;
 397 };
 398
 399 static int acpi_populate_gpio_lookup(struct acpi_resource *ares, void *data)
 400 {
 401         struct acpi_gpio_lookup *lookup = data;
 402
 403         if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
 404                 return 1;
 405
 406         if (lookup->n++ == lookup->index && !lookup->desc) {
 407                 const struct acpi_resource_gpio *agpio = &ares->data.gpio;
 408                 int pin_index = lookup->pin_index;
 409
 410                 if (pin_index >= agpio->pin_table_length)
 411                         return 1;
 412
 413                 lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
 414                                               agpio->pin_table[pin_index]);
 415                 lookup->info.gpioint =
 416                         agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
 417
 418                 /*
 419                  * ActiveLow is only specified for GpioInt resource. If
 420                  * GpioIo is used then the only way to set the flag is
 421                  * to use _DSD "gpios" property.
 422                  * Note: we expect here:
 423                  * - ACPI_ACTIVE_LOW == GPIO_ACTIVE_LOW
 424                  * - ACPI_ACTIVE_HIGH == GPIO_ACTIVE_HIGH
 425                  */
 426                 if (lookup->info.gpioint) {
 427                         lookup->info.polarity = agpio->polarity;
 428                         lookup->info.triggering = agpio->triggering;
 429                 }
 430
 431         }
 432
 433         return 1;
 434 }
 435
 436 static int acpi_gpio_resource_lookup(struct acpi_gpio_lookup *lookup,
 437                                      struct acpi_gpio_info *info)
 438 {
 439         struct list_head res_list;
 440         int ret;
 441
 442         INIT_LIST_HEAD(&res_list);
 443
 444         ret = acpi_dev_get_resources(lookup->adev, &res_list,
 445                                      acpi_populate_gpio_lookup,
 446                                      lookup);
 447         if (ret < 0)
 448                 return ret;
 449
 450         acpi_dev_free_resource_list(&res_list);
 451
 452         if (!lookup->desc)
 453                 return -ENOENT;
 454
 455         if (info) {
 456                 *info = lookup->info;
 457                 if (lookup->active_low)
 458                         info->polarity = lookup->active_low;
 459         }
 460         return 0;
 461 }
 462
 463 static int acpi_gpio_property_lookup(struct fwnode_handle *fwnode,
 464                                      const char *propname, int index,
 465                                      struct acpi_gpio_lookup *lookup)
 466 {
 467         struct acpi_reference_args args;
 468         int ret;
 469
 470         memset(&args, 0, sizeof(args));
 471         ret = acpi_node_get_property_reference(fwnode, propname, index, &args);
 472         if (ret) {
 473                 struct acpi_device *adev = to_acpi_device_node(fwnode);
 474
 475                 if (!adev)
 476                         return ret;
 477
 478                 if (!acpi_get_driver_gpio_data(adev, propname, index, &args))
 479                         return ret;
 480         }
 481         /*
 482          * The property was found and resolved, so need to lookup the GPIO based
 483          * on returned args.
 484          */
 485         lookup->adev = args.adev;
 486         if (args.nargs >= 2) {
 487                 lookup->index = args.args[0];
 488                 lookup->pin_index = args.args[1];
 489                 /* 3rd argument, if present is used to specify active_low. */
 490                 if (args.nargs >= 3)
 491                         lookup->active_low = !!args.args[2];
 492         }
 493         return 0;
 494 }
 495
 496 /**
 497  * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
 498  * @adev: pointer to a ACPI device to get GPIO from
 499  * @propname: Property name of the GPIO (optional)
 500  * @index: index of GpioIo/GpioInt resource (starting from %0)
 501  * @info: info pointer to fill in (optional)
 502  *
 503  * Function goes through ACPI resources for @adev and based on @index looks
 504  * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
 505  * and returns it. @index matches GpioIo/GpioInt resources only so if there
 506  * are total %3 GPIO resources, the index goes from %0 to %2.
 507  *
 508  * If @propname is specified the GPIO is looked using device property. In
 509  * that case @index is used to select the GPIO entry in the property value
 510  * (in case of multiple).
 511  *
 512  * If the GPIO cannot be translated or there is an error an ERR_PTR is
 513  * returned.
 514  *
 515  * Note: if the GPIO resource has multiple entries in the pin list, this
 516  * function only returns the first.
 517  */
 518 static struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
 519                                           const char *propname, int index,
 520                                           struct acpi_gpio_info *info)
 521 {
 522         struct acpi_gpio_lookup lookup;
 523         int ret;
 524
 525         if (!adev)
 526                 return ERR_PTR(-ENODEV);
 527
 528         memset(&lookup, 0, sizeof(lookup));
 529         lookup.index = index;
 530
 531         if (propname) {
 532                 dev_dbg(&adev->dev, "GPIO: looking up %s\n", propname);
 533
 534                 ret = acpi_gpio_property_lookup(acpi_fwnode_handle(adev),
 535                                                 propname, index, &lookup);
 536                 if (ret)
 537                         return ERR_PTR(ret);
 538
 539                 dev_dbg(&adev->dev, "GPIO: _DSD returned %s %d %d %u\n",
 540                         dev_name(&lookup.adev->dev), lookup.index,
 541                         lookup.pin_index, lookup.active_low);
 542         } else {
 543                 dev_dbg(&adev->dev, "GPIO: looking up %d in _CRS\n", index);
 544                 lookup.adev = adev;
 545         }
 546
 547         ret = acpi_gpio_resource_lookup(&lookup, info);
 548         return ret ? ERR_PTR(ret) : lookup.desc;
 549 }
 550
 551 struct gpio_desc *acpi_find_gpio(struct device *dev,
 552                                  const char *con_id,
 553                                  unsigned int idx,
 554                                  enum gpiod_flags flags,
 555                                  enum gpio_lookup_flags *lookupflags)
 556 {
 557         struct acpi_device *adev = ACPI_COMPANION(dev);
 558         struct acpi_gpio_info info;
 559         struct gpio_desc *desc;
 560         char propname[32];
 561         int i;
 562
 563         /* Try first from _DSD */
 564         for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
 565                 if (con_id && strcmp(con_id, "gpios")) {
 566                         snprintf(propname, sizeof(propname), "%s-%s",
 567                                  con_id, gpio_suffixes[i]);
 568                 } else {
 569                         snprintf(propname, sizeof(propname), "%s",
 570                                  gpio_suffixes[i]);
 571                 }
 572
 573                 desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
 574                 if (!IS_ERR(desc))
 575                         break;
 576                 if (PTR_ERR(desc) == -EPROBE_DEFER)
 577                         return ERR_CAST(desc);
 578         }
 579
 580         /* Then from plain _CRS GPIOs */
 581         if (IS_ERR(desc)) {
 582                 if (!acpi_can_fallback_to_crs(adev, con_id))
 583                         return ERR_PTR(-ENOENT);
 584
 585                 desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
 586                 if (IS_ERR(desc))
 587                         return desc;
 588
 589                 if ((flags == GPIOD_OUT_LOW || flags == GPIOD_OUT_HIGH) &&
 590                     info.gpioint) {
 591                         dev_dbg(dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
 592                         return ERR_PTR(-ENOENT);
 593                 }
 594         }
 595
 596         if (info.polarity == GPIO_ACTIVE_LOW)
 597                 *lookupflags |= GPIO_ACTIVE_LOW;
 598
 599         return desc;
 600 }
 601
 602 /**
 603  * acpi_node_get_gpiod() - get a GPIO descriptor from ACPI resources
 604  * @fwnode: pointer to an ACPI firmware node to get the GPIO information from
 605  * @propname: Property name of the GPIO
 606  * @index: index of GpioIo/GpioInt resource (starting from %0)
 607  * @info: info pointer to fill in (optional)
 608  *
 609  * If @fwnode is an ACPI device object, call %acpi_get_gpiod_by_index() for it.
 610  * Otherwise (ie. it is a data-only non-device object), use the property-based
 611  * GPIO lookup to get to the GPIO resource with the relevant information and use
 612  * that to obtain the GPIO descriptor to return.
 613  */
 614 struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
 615                                       const char *propname, int index,
 616                                       struct acpi_gpio_info *info)
 617 {
 618         struct acpi_gpio_lookup lookup;
 619         struct acpi_device *adev;
 620         int ret;
 621
 622         adev = to_acpi_device_node(fwnode);
 623         if (adev)
 624                 return acpi_get_gpiod_by_index(adev, propname, index, info);
 625
 626         if (!is_acpi_data_node(fwnode))
 627                 return ERR_PTR(-ENODEV);
 628
 629         if (!propname)
 630                 return ERR_PTR(-EINVAL);
 631
 632         memset(&lookup, 0, sizeof(lookup));
 633         lookup.index = index;
 634
 635         ret = acpi_gpio_property_lookup(fwnode, propname, index, &lookup);
 636         if (ret)
 637                 return ERR_PTR(ret);
 638
 639         ret = acpi_gpio_resource_lookup(&lookup, info);
 640         return ret ? ERR_PTR(ret) : lookup.desc;
 641 }
 642
 643 /**
 644  * acpi_dev_gpio_irq_get() - Find GpioInt and translate it to Linux IRQ number
 645  * @adev: pointer to a ACPI device to get IRQ from
 646  * @index: index of GpioInt resource (starting from %0)
 647  *
 648  * If the device has one or more GpioInt resources, this function can be
 649  * used to translate from the GPIO offset in the resource to the Linux IRQ
 650  * number.
 651  *
 652  * Return: Linux IRQ number (>%0) on success, negative errno on failure.
 653  */
 654 int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
 655 {
 656         int idx, i;
 657         unsigned int irq_flags;
 658         int ret = -ENOENT;
 659
 660         for (i = 0, idx = 0; idx <= index; i++) {
 661                 struct acpi_gpio_info info;
 662                 struct gpio_desc *desc;
 663
 664                 desc = acpi_get_gpiod_by_index(adev, NULL, i, &info);
 665                 if (IS_ERR(desc)) {
 666                         ret = PTR_ERR(desc);
 667                         break;
 668                 }
 669                 if (info.gpioint && idx++ == index) {
 670                         int irq = gpiod_to_irq(desc);
 671
 672                         if (irq < 0)
 673                                 return irq;
 674
 675                         irq_flags = acpi_dev_get_irq_type(info.triggering,
 676                                                           info.polarity);
 677
 678                         /* Set type if specified and different than the current one */
 679                         if (irq_flags != IRQ_TYPE_NONE &&
 680                             irq_flags != irq_get_trigger_type(irq))
 681                                 irq_set_irq_type(irq, irq_flags);
 682
 683                         return irq;
 684                 }
 685
 686         }
 687         return ret;
 688 }
 689 EXPORT_SYMBOL_GPL(acpi_dev_gpio_irq_get);
 690
 691 static acpi_status
 692 acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
 693                             u32 bits, u64 *value, void *handler_context,
 694                             void *region_context)
 695 {
 696         struct acpi_gpio_chip *achip = region_context;
 697         struct gpio_chip *chip = achip->chip;
 698         struct acpi_resource_gpio *agpio;
 699         struct acpi_resource *ares;
 700         int pin_index = (int)address;
 701         acpi_status status;
 702         bool pull_up;
 703         int length;
 704         int i;
 705
 706         status = acpi_buffer_to_resource(achip->conn_info.connection,
 707                                          achip->conn_info.length, &ares);
 708         if (ACPI_FAILURE(status))
 709                 return status;
 710
 711         if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) {
 712                 ACPI_FREE(ares);
 713                 return AE_BAD_PARAMETER;
 714         }
 715
 716         agpio = &ares->data.gpio;
 717         pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP;
 718
 719         if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT &&
 720             function == ACPI_WRITE)) {
 721                 ACPI_FREE(ares);
 722                 return AE_BAD_PARAMETER;
 723         }
 724
 725         length = min(agpio->pin_table_length, (u16)(pin_index + bits));
 726         for (i = pin_index; i < length; ++i) {
 727                 int pin = agpio->pin_table[i];
 728                 struct acpi_gpio_connection *conn;
 729                 struct gpio_desc *desc;
 730                 bool found;
 731
 732                 pin = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, pin);
 733                 if (pin < 0) {
 734                         status = AE_BAD_PARAMETER;
 735                         goto out;
 736                 }
 737
 738                 mutex_lock(&achip->conn_lock);
 739
 740                 found = false;
 741                 list_for_each_entry(conn, &achip->conns, node) {
 742                         if (conn->pin == pin) {
 743                                 found = true;
 744                                 desc = conn->desc;
 745                                 break;
 746                         }
 747                 }
 748
 749                 /*
 750                  * The same GPIO can be shared between operation region and
 751                  * event but only if the access here is ACPI_READ. In that
 752                  * case we "borrow" the event GPIO instead.
 753                  */
 754                 if (!found && agpio->sharable == ACPI_SHARED &&
 755                      function == ACPI_READ) {
 756                         struct acpi_gpio_event *event;
 757
 758                         list_for_each_entry(event, &achip->events, node) {
 759                                 if (event->pin == pin) {
 760                                         desc = event->desc;
 761                                         found = true;
 762                                         break;
 763                                 }
 764                         }
 765                 }
 766
 767                 if (!found) {
 768                         desc = gpiochip_request_own_desc(chip, pin,
 769                                                          "ACPI:OpRegion");
 770                         if (IS_ERR(desc)) {
 771                                 status = AE_ERROR;
 772                                 mutex_unlock(&achip->conn_lock);
 773                                 goto out;
 774                         }
 775
 776                         switch (agpio->io_restriction) {
 777                         case ACPI_IO_RESTRICT_INPUT:
 778                                 gpiod_direction_input(desc);
 779                                 break;
 780                         case ACPI_IO_RESTRICT_OUTPUT:
 781                                 /*
 782                                  * ACPI GPIO resources don't contain an
 783                                  * initial value for the GPIO. Therefore we
 784                                  * deduce that value from the pull field
 785                                  * instead. If the pin is pulled up we
 786                                  * assume default to be high, otherwise
 787                                  * low.
 788                                  */
 789                                 gpiod_direction_output(desc, pull_up);
 790                                 break;
 791                         default:
 792                                 /*
 793                                  * Assume that the BIOS has configured the
 794                                  * direction and pull accordingly.
 795                                  */
 796                                 break;
 797                         }
 798
 799                         conn = kzalloc(sizeof(*conn), GFP_KERNEL);
 800                         if (!conn) {
 801                                 status = AE_NO_MEMORY;
 802                                 gpiochip_free_own_desc(desc);
 803                                 mutex_unlock(&achip->conn_lock);
 804                                 goto out;
 805                         }
 806
 807                         conn->pin = pin;
 808                         conn->desc = desc;
 809                         list_add_tail(&conn->node, &achip->conns);
 810                 }
 811
 812                 mutex_unlock(&achip->conn_lock);
 813
 814                 if (function == ACPI_WRITE)
 815                         gpiod_set_raw_value_cansleep(desc,
 816                                                      !!((1 << i) & *value));
 817                 else
 818                         *value |= (u64)gpiod_get_raw_value_cansleep(desc) << i;
 819         }
 820
 821 out:
 822         ACPI_FREE(ares);
 823         return status;
 824 }
 825
 826 static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip)
 827 {
 828         struct gpio_chip *chip = achip->chip;
 829         acpi_handle handle = ACPI_HANDLE(chip->parent);
 830         acpi_status status;
 831
 832         INIT_LIST_HEAD(&achip->conns);
 833         mutex_init(&achip->conn_lock);
 834         status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
 835                                                     acpi_gpio_adr_space_handler,
 836                                                     NULL, achip);
 837         if (ACPI_FAILURE(status))
 838                 dev_err(chip->parent,
 839                         "Failed to install GPIO OpRegion handler\n");
 840 }
 841
 842 static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
 843 {
 844         struct gpio_chip *chip = achip->chip;
 845         acpi_handle handle = ACPI_HANDLE(chip->parent);
 846         struct acpi_gpio_connection *conn, *tmp;
 847         acpi_status status;
 848
 849         status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
 850                                                    acpi_gpio_adr_space_handler);
 851         if (ACPI_FAILURE(status)) {
 852                 dev_err(chip->parent,
 853                         "Failed to remove GPIO OpRegion handler\n");
 854                 return;
 855         }
 856
 857         list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) {
 858                 gpiochip_free_own_desc(conn->desc);
 859                 list_del(&conn->node);
 860                 kfree(conn);
 861         }
 862 }
 863
 864 void acpi_gpiochip_add(struct gpio_chip *chip)
 865 {
 866         struct acpi_gpio_chip *acpi_gpio;
 867         acpi_handle handle;
 868         acpi_status status;
 869
 870         if (!chip || !chip->parent)
 871                 return;
 872
 873         handle = ACPI_HANDLE(chip->parent);
 874         if (!handle)
 875                 return;
 876
 877         acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
 878         if (!acpi_gpio) {
 879                 dev_err(chip->parent,
 880                         "Failed to allocate memory for ACPI GPIO chip\n");
 881                 return;
 882         }
 883
 884         acpi_gpio->chip = chip;
 885         INIT_LIST_HEAD(&acpi_gpio->events);
 886
 887         status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
 888         if (ACPI_FAILURE(status)) {
 889                 dev_err(chip->parent, "Failed to attach ACPI GPIO chip\n");
 890                 kfree(acpi_gpio);
 891                 return;
 892         }
 893
 894         acpi_gpiochip_request_regions(acpi_gpio);
 895         acpi_walk_dep_device_list(handle);
 896 }
 897
 898 void acpi_gpiochip_remove(struct gpio_chip *chip)
 899 {
 900         struct acpi_gpio_chip *acpi_gpio;
 901         acpi_handle handle;
 902         acpi_status status;
 903
 904         if (!chip || !chip->parent)
 905                 return;
 906
 907         handle = ACPI_HANDLE(chip->parent);
 908         if (!handle)
 909                 return;
 910
 911         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 912         if (ACPI_FAILURE(status)) {
 913                 dev_warn(chip->parent, "Failed to retrieve ACPI GPIO chip\n");
 914                 return;
 915         }
 916
 917         acpi_gpiochip_free_regions(acpi_gpio);
 918
 919         acpi_detach_data(handle, acpi_gpio_chip_dh);
 920         kfree(acpi_gpio);
 921 }
 922
 923 static unsigned int acpi_gpio_package_count(const union acpi_object *obj)
 924 {
 925         const union acpi_object *element = obj->package.elements;
 926         const union acpi_object *end = element + obj->package.count;
 927         unsigned int count = 0;
 928
 929         while (element < end) {
 930                 if (element->type == ACPI_TYPE_LOCAL_REFERENCE)
 931                         count++;
 932
 933                 element++;
 934         }
 935         return count;
 936 }
 937
 938 static int acpi_find_gpio_count(struct acpi_resource *ares, void *data)
 939 {
 940         unsigned int *count = data;
 941
 942         if (ares->type == ACPI_RESOURCE_TYPE_GPIO)
 943                 *count += ares->data.gpio.pin_table_length;
 944
 945         return 1;
 946 }
 947
 948 /**
 949  * acpi_gpio_count - return the number of GPIOs associated with a
 950  *              device / function or -ENOENT if no GPIO has been
 951  *              assigned to the requested function.
 952  * @dev:        GPIO consumer, can be NULL for system-global GPIOs
 953  * @con_id:     function within the GPIO consumer
 954  */
 955 int acpi_gpio_count(struct device *dev, const char *con_id)
 956 {
 957         struct acpi_device *adev = ACPI_COMPANION(dev);
 958         const union acpi_object *obj;
 959         const struct acpi_gpio_mapping *gm;
 960         int count = -ENOENT;
 961         int ret;
 962         char propname[32];
 963         unsigned int i;
 964
 965         /* Try first from _DSD */
 966         for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
 967                 if (con_id && strcmp(con_id, "gpios"))
 968                         snprintf(propname, sizeof(propname), "%s-%s",
 969                                  con_id, gpio_suffixes[i]);
 970                 else
 971                         snprintf(propname, sizeof(propname), "%s",
 972                                  gpio_suffixes[i]);
 973
 974                 ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY,
 975                                             &obj);
 976                 if (ret == 0) {
 977                         if (obj->type == ACPI_TYPE_LOCAL_REFERENCE)
 978                                 count = 1;
 979                         else if (obj->type == ACPI_TYPE_PACKAGE)
 980                                 count = acpi_gpio_package_count(obj);
 981                 } else if (adev->driver_gpios) {
 982                         for (gm = adev->driver_gpios; gm->name; gm++)
 983                                 if (strcmp(propname, gm->name) == 0) {
 984                                         count = gm->size;
 985                                         break;
 986                                 }
 987                 }
 988                 if (count >= 0)
 989                         break;
 990         }
 991
 992         /* Then from plain _CRS GPIOs */
 993         if (count < 0) {
 994                 struct list_head resource_list;
 995                 unsigned int crs_count = 0;
 996
 997                 INIT_LIST_HEAD(&resource_list);
 998                 acpi_dev_get_resources(adev, &resource_list,
 999                                        acpi_find_gpio_count, &crs_count);
1000                 acpi_dev_free_resource_list(&resource_list);
1001                 if (crs_count > 0)
1002                         count = crs_count;
1003         }
1004         return count;
1005 }
1006
1007 struct acpi_crs_lookup {
1008         struct list_head node;
1009         struct acpi_device *adev;
1010         const char *con_id;
1011 };
1012
1013 static DEFINE_MUTEX(acpi_crs_lookup_lock);
1014 static LIST_HEAD(acpi_crs_lookup_list);
1015
1016 bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id)
1017 {
1018         struct acpi_crs_lookup *l, *lookup = NULL;
1019
1020         /* Never allow fallback if the device has properties */
1021         if (adev->data.properties || adev->driver_gpios)
1022                 return false;
1023
1024         mutex_lock(&acpi_crs_lookup_lock);
1025
1026         list_for_each_entry(l, &acpi_crs_lookup_list, node) {
1027                 if (l->adev == adev) {
1028                         lookup = l;
1029                         break;
1030                 }
1031         }
1032
1033         if (!lookup) {
1034                 lookup = kmalloc(sizeof(*lookup), GFP_KERNEL);
1035                 if (lookup) {
1036                         lookup->adev = adev;
1037                         lookup->con_id = kstrdup(con_id, GFP_KERNEL);
1038                         list_add_tail(&lookup->node, &acpi_crs_lookup_list);
1039                 }
1040         }
1041
1042         mutex_unlock(&acpi_crs_lookup_lock);
1043
1044         return lookup &&
1045                 ((!lookup->con_id && !con_id) ||
1046                  (lookup->con_id && con_id &&
1047                   strcmp(lookup->con_id, con_id) == 0));
1048 }