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                  * Polarity and triggering are only specified for GpioInt
 420                  * resource.
 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,
 444                                      acpi_populate_gpio_lookup,
 445                                      lookup);
 446         if (ret < 0)
 447                 return ret;
 448
 449         acpi_dev_free_resource_list(&res_list);
 450
 451         if (!lookup->desc)
 452                 return -ENOENT;
 453
 454         if (info) {
 455                 *info = lookup->info;
 456                 if (lookup->active_low)
 457                         info->polarity = lookup->active_low;
 458         }
 459         return 0;
 460 }
 461
 462 static int acpi_gpio_property_lookup(struct fwnode_handle *fwnode,
 463                                      const char *propname, int index,
 464                                      struct acpi_gpio_lookup *lookup)
 465 {
 466         struct acpi_reference_args args;
 467         int ret;
 468
 469         memset(&args, 0, sizeof(args));
 470         ret = __acpi_node_get_property_reference(fwnode, propname, index, 3,
 471                                                  &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 != 3)
 487                 return -EPROTO;
 488
 489         lookup->index = args.args[0];
 490         lookup->pin_index = args.args[1];
 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) || (PTR_ERR(desc) == -EPROBE_DEFER))
 575                         break;
 576         }
 577
 578         /* Then from plain _CRS GPIOs */
 579         if (IS_ERR(desc)) {
 580                 if (!acpi_can_fallback_to_crs(adev, con_id))
 581                         return ERR_PTR(-ENOENT);
 582
 583                 desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
 584                 if (IS_ERR(desc))
 585                         return desc;
 586
 587                 if ((flags == GPIOD_OUT_LOW || flags == GPIOD_OUT_HIGH) &&
 588                     info.gpioint) {
 589                         dev_dbg(dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
 590                         return ERR_PTR(-ENOENT);
 591                 }
 592         }
 593
 594         if (info.polarity == GPIO_ACTIVE_LOW)
 595                 *lookupflags |= GPIO_ACTIVE_LOW;
 596
 597         return desc;
 598 }
 599
 600 /**
 601  * acpi_node_get_gpiod() - get a GPIO descriptor from ACPI resources
 602  * @fwnode: pointer to an ACPI firmware node to get the GPIO information from
 603  * @propname: Property name of the GPIO
 604  * @index: index of GpioIo/GpioInt resource (starting from %0)
 605  * @info: info pointer to fill in (optional)
 606  *
 607  * If @fwnode is an ACPI device object, call %acpi_get_gpiod_by_index() for it.
 608  * Otherwise (ie. it is a data-only non-device object), use the property-based
 609  * GPIO lookup to get to the GPIO resource with the relevant information and use
 610  * that to obtain the GPIO descriptor to return.
 611  */
 612 struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
 613                                       const char *propname, int index,
 614                                       struct acpi_gpio_info *info)
 615 {
 616         struct acpi_gpio_lookup lookup;
 617         struct acpi_device *adev;
 618         int ret;
 619
 620         adev = to_acpi_device_node(fwnode);
 621         if (adev)
 622                 return acpi_get_gpiod_by_index(adev, propname, index, info);
 623
 624         if (!is_acpi_data_node(fwnode))
 625                 return ERR_PTR(-ENODEV);
 626
 627         if (!propname)
 628                 return ERR_PTR(-EINVAL);
 629
 630         memset(&lookup, 0, sizeof(lookup));
 631         lookup.index = index;
 632
 633         ret = acpi_gpio_property_lookup(fwnode, propname, index, &lookup);
 634         if (ret)
 635                 return ERR_PTR(ret);
 636
 637         ret = acpi_gpio_resource_lookup(&lookup, info);
 638         return ret ? ERR_PTR(ret) : lookup.desc;
 639 }
 640
 641 /**
 642  * acpi_dev_gpio_irq_get() - Find GpioInt and translate it to Linux IRQ number
 643  * @adev: pointer to a ACPI device to get IRQ from
 644  * @index: index of GpioInt resource (starting from %0)
 645  *
 646  * If the device has one or more GpioInt resources, this function can be
 647  * used to translate from the GPIO offset in the resource to the Linux IRQ
 648  * number.
 649  *
 650  * Return: Linux IRQ number (>%0) on success, negative errno on failure.
 651  */
 652 int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
 653 {
 654         int idx, i;
 655         unsigned int irq_flags;
 656         int ret = -ENOENT;
 657
 658         for (i = 0, idx = 0; idx <= index; i++) {
 659                 struct acpi_gpio_info info;
 660                 struct gpio_desc *desc;
 661
 662                 desc = acpi_get_gpiod_by_index(adev, NULL, i, &info);
 663                 if (IS_ERR(desc)) {
 664                         ret = PTR_ERR(desc);
 665                         break;
 666                 }
 667                 if (info.gpioint && idx++ == index) {
 668                         int irq = gpiod_to_irq(desc);
 669
 670                         if (irq < 0)
 671                                 return irq;
 672
 673                         irq_flags = acpi_dev_get_irq_type(info.triggering,
 674                                                           info.polarity);
 675
 676                         /* Set type if specified and different than the current one */
 677                         if (irq_flags != IRQ_TYPE_NONE &&
 678                             irq_flags != irq_get_trigger_type(irq))
 679                                 irq_set_irq_type(irq, irq_flags);
 680
 681                         return irq;
 682                 }
 683
 684         }
 685         return ret;
 686 }
 687 EXPORT_SYMBOL_GPL(acpi_dev_gpio_irq_get);
 688
 689 static acpi_status
 690 acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
 691                             u32 bits, u64 *value, void *handler_context,
 692                             void *region_context)
 693 {
 694         struct acpi_gpio_chip *achip = region_context;
 695         struct gpio_chip *chip = achip->chip;
 696         struct acpi_resource_gpio *agpio;
 697         struct acpi_resource *ares;
 698         int pin_index = (int)address;
 699         acpi_status status;
 700         bool pull_up;
 701         int length;
 702         int i;
 703
 704         status = acpi_buffer_to_resource(achip->conn_info.connection,
 705                                          achip->conn_info.length, &ares);
 706         if (ACPI_FAILURE(status))
 707                 return status;
 708
 709         if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) {
 710                 ACPI_FREE(ares);
 711                 return AE_BAD_PARAMETER;
 712         }
 713
 714         agpio = &ares->data.gpio;
 715         pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP;
 716
 717         if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT &&
 718             function == ACPI_WRITE)) {
 719                 ACPI_FREE(ares);
 720                 return AE_BAD_PARAMETER;
 721         }
 722
 723         length = min(agpio->pin_table_length, (u16)(pin_index + bits));
 724         for (i = pin_index; i < length; ++i) {
 725                 int pin = agpio->pin_table[i];
 726                 struct acpi_gpio_connection *conn;
 727                 struct gpio_desc *desc;
 728                 bool found;
 729
 730                 pin = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, pin);
 731                 if (pin < 0) {
 732                         status = AE_BAD_PARAMETER;
 733                         goto out;
 734                 }
 735
 736                 mutex_lock(&achip->conn_lock);
 737
 738                 found = false;
 739                 list_for_each_entry(conn, &achip->conns, node) {
 740                         if (conn->pin == pin) {
 741                                 found = true;
 742                                 desc = conn->desc;
 743                                 break;
 744                         }
 745                 }
 746
 747                 /*
 748                  * The same GPIO can be shared between operation region and
 749                  * event but only if the access here is ACPI_READ. In that
 750                  * case we "borrow" the event GPIO instead.
 751                  */
 752                 if (!found && agpio->sharable == ACPI_SHARED &&
 753                      function == ACPI_READ) {
 754                         struct acpi_gpio_event *event;
 755
 756                         list_for_each_entry(event, &achip->events, node) {
 757                                 if (event->pin == pin) {
 758                                         desc = event->desc;
 759                                         found = true;
 760                                         break;
 761                                 }
 762                         }
 763                 }
 764
 765                 if (!found) {
 766                         desc = gpiochip_request_own_desc(chip, pin,
 767                                                          "ACPI:OpRegion");
 768                         if (IS_ERR(desc)) {
 769                                 status = AE_ERROR;
 770                                 mutex_unlock(&achip->conn_lock);
 771                                 goto out;
 772                         }
 773
 774                         switch (agpio->io_restriction) {
 775                         case ACPI_IO_RESTRICT_INPUT:
 776                                 gpiod_direction_input(desc);
 777                                 break;
 778                         case ACPI_IO_RESTRICT_OUTPUT:
 779                                 /*
 780                                  * ACPI GPIO resources don't contain an
 781                                  * initial value for the GPIO. Therefore we
 782                                  * deduce that value from the pull field
 783                                  * instead. If the pin is pulled up we
 784                                  * assume default to be high, otherwise
 785                                  * low.
 786                                  */
 787                                 gpiod_direction_output(desc, pull_up);
 788                                 break;
 789                         default:
 790                                 /*
 791                                  * Assume that the BIOS has configured the
 792                                  * direction and pull accordingly.
 793                                  */
 794                                 break;
 795                         }
 796
 797                         conn = kzalloc(sizeof(*conn), GFP_KERNEL);
 798                         if (!conn) {
 799                                 status = AE_NO_MEMORY;
 800                                 gpiochip_free_own_desc(desc);
 801                                 mutex_unlock(&achip->conn_lock);
 802                                 goto out;
 803                         }
 804
 805                         conn->pin = pin;
 806                         conn->desc = desc;
 807                         list_add_tail(&conn->node, &achip->conns);
 808                 }
 809
 810                 mutex_unlock(&achip->conn_lock);
 811
 812                 if (function == ACPI_WRITE)
 813                         gpiod_set_raw_value_cansleep(desc,
 814                                                      !!((1 << i) & *value));
 815                 else
 816                         *value |= (u64)gpiod_get_raw_value_cansleep(desc) << i;
 817         }
 818
 819 out:
 820         ACPI_FREE(ares);
 821         return status;
 822 }
 823
 824 static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip)
 825 {
 826         struct gpio_chip *chip = achip->chip;
 827         acpi_handle handle = ACPI_HANDLE(chip->parent);
 828         acpi_status status;
 829
 830         INIT_LIST_HEAD(&achip->conns);
 831         mutex_init(&achip->conn_lock);
 832         status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
 833                                                     acpi_gpio_adr_space_handler,
 834                                                     NULL, achip);
 835         if (ACPI_FAILURE(status))
 836                 dev_err(chip->parent,
 837                         "Failed to install GPIO OpRegion handler\n");
 838 }
 839
 840 static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
 841 {
 842         struct gpio_chip *chip = achip->chip;
 843         acpi_handle handle = ACPI_HANDLE(chip->parent);
 844         struct acpi_gpio_connection *conn, *tmp;
 845         acpi_status status;
 846
 847         status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
 848                                                    acpi_gpio_adr_space_handler);
 849         if (ACPI_FAILURE(status)) {
 850                 dev_err(chip->parent,
 851                         "Failed to remove GPIO OpRegion handler\n");
 852                 return;
 853         }
 854
 855         list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) {
 856                 gpiochip_free_own_desc(conn->desc);
 857                 list_del(&conn->node);
 858                 kfree(conn);
 859         }
 860 }
 861
 862 static struct gpio_desc *acpi_gpiochip_parse_own_gpio(
 863         struct acpi_gpio_chip *achip, struct fwnode_handle *fwnode,
 864         const char **name, unsigned int *lflags, unsigned int *dflags)
 865 {
 866         struct gpio_chip *chip = achip->chip;
 867         struct gpio_desc *desc;
 868         u32 gpios[2];
 869         int ret;
 870
 871         *lflags = 0;
 872         *dflags = 0;
 873         *name = NULL;
 874
 875         ret = fwnode_property_read_u32_array(fwnode, "gpios", gpios,
 876                                              ARRAY_SIZE(gpios));
 877         if (ret < 0)
 878                 return ERR_PTR(ret);
 879
 880         ret = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, gpios[0]);
 881         if (ret < 0)
 882                 return ERR_PTR(ret);
 883
 884         desc = gpiochip_get_desc(chip, ret);
 885         if (IS_ERR(desc))
 886                 return desc;
 887
 888         if (gpios[1])
 889                 *lflags |= GPIO_ACTIVE_LOW;
 890
 891         if (fwnode_property_present(fwnode, "input"))
 892                 *dflags |= GPIOD_IN;
 893         else if (fwnode_property_present(fwnode, "output-low"))
 894                 *dflags |= GPIOD_OUT_LOW;
 895         else if (fwnode_property_present(fwnode, "output-high"))
 896                 *dflags |= GPIOD_OUT_HIGH;
 897         else
 898                 return ERR_PTR(-EINVAL);
 899
 900         fwnode_property_read_string(fwnode, "line-name", name);
 901
 902         return desc;
 903 }
 904
 905 static void acpi_gpiochip_scan_gpios(struct acpi_gpio_chip *achip)
 906 {
 907         struct gpio_chip *chip = achip->chip;
 908         struct fwnode_handle *fwnode;
 909
 910         device_for_each_child_node(chip->parent, fwnode) {
 911                 unsigned int lflags, dflags;
 912                 struct gpio_desc *desc;
 913                 const char *name;
 914                 int ret;
 915
 916                 if (!fwnode_property_present(fwnode, "gpio-hog"))
 917                         continue;
 918
 919                 desc = acpi_gpiochip_parse_own_gpio(achip, fwnode, &name,
 920                                                     &lflags, &dflags);
 921                 if (IS_ERR(desc))
 922                         continue;
 923
 924                 ret = gpiod_hog(desc, name, lflags, dflags);
 925                 if (ret) {
 926                         dev_err(chip->parent, "Failed to hog GPIO\n");
 927                         fwnode_handle_put(fwnode);
 928                         return;
 929                 }
 930         }
 931 }
 932
 933 void acpi_gpiochip_add(struct gpio_chip *chip)
 934 {
 935         struct acpi_gpio_chip *acpi_gpio;
 936         acpi_handle handle;
 937         acpi_status status;
 938
 939         if (!chip || !chip->parent)
 940                 return;
 941
 942         handle = ACPI_HANDLE(chip->parent);
 943         if (!handle)
 944                 return;
 945
 946         acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
 947         if (!acpi_gpio) {
 948                 dev_err(chip->parent,
 949                         "Failed to allocate memory for ACPI GPIO chip\n");
 950                 return;
 951         }
 952
 953         acpi_gpio->chip = chip;
 954         INIT_LIST_HEAD(&acpi_gpio->events);
 955
 956         status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
 957         if (ACPI_FAILURE(status)) {
 958                 dev_err(chip->parent, "Failed to attach ACPI GPIO chip\n");
 959                 kfree(acpi_gpio);
 960                 return;
 961         }
 962
 963         if (!chip->names)
 964                 devprop_gpiochip_set_names(chip);
 965
 966         acpi_gpiochip_request_regions(acpi_gpio);
 967         acpi_gpiochip_scan_gpios(acpi_gpio);
 968         acpi_walk_dep_device_list(handle);
 969 }
 970
 971 void acpi_gpiochip_remove(struct gpio_chip *chip)
 972 {
 973         struct acpi_gpio_chip *acpi_gpio;
 974         acpi_handle handle;
 975         acpi_status status;
 976
 977         if (!chip || !chip->parent)
 978                 return;
 979
 980         handle = ACPI_HANDLE(chip->parent);
 981         if (!handle)
 982                 return;
 983
 984         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 985         if (ACPI_FAILURE(status)) {
 986                 dev_warn(chip->parent, "Failed to retrieve ACPI GPIO chip\n");
 987                 return;
 988         }
 989
 990         acpi_gpiochip_free_regions(acpi_gpio);
 991
 992         acpi_detach_data(handle, acpi_gpio_chip_dh);
 993         kfree(acpi_gpio);
 994 }
 995
 996 static int acpi_gpio_package_count(const union acpi_object *obj)
 997 {
 998         const union acpi_object *element = obj->package.elements;
 999         const union acpi_object *end = element + obj->package.count;
1000         unsigned int count = 0;
1001
1002         while (element < end) {
1003                 switch (element->type) {
1004                 case ACPI_TYPE_LOCAL_REFERENCE:
1005                         element += 3;
1006                         /* Fallthrough */
1007                 case ACPI_TYPE_INTEGER:
1008                         element++;
1009                         count++;
1010                         break;
1011
1012                 default:
1013                         return -EPROTO;
1014                 }
1015         }
1016
1017         return count;
1018 }
1019
1020 static int acpi_find_gpio_count(struct acpi_resource *ares, void *data)
1021 {
1022         unsigned int *count = data;
1023
1024         if (ares->type == ACPI_RESOURCE_TYPE_GPIO)
1025                 *count += ares->data.gpio.pin_table_length;
1026
1027         return 1;
1028 }
1029
1030 /**
1031  * acpi_gpio_count - return the number of GPIOs associated with a
1032  *              device / function or -ENOENT if no GPIO has been
1033  *              assigned to the requested function.
1034  * @dev:        GPIO consumer, can be NULL for system-global GPIOs
1035  * @con_id:     function within the GPIO consumer
1036  */
1037 int acpi_gpio_count(struct device *dev, const char *con_id)
1038 {
1039         struct acpi_device *adev = ACPI_COMPANION(dev);
1040         const union acpi_object *obj;
1041         const struct acpi_gpio_mapping *gm;
1042         int count = -ENOENT;
1043         int ret;
1044         char propname[32];
1045         unsigned int i;
1046
1047         /* Try first from _DSD */
1048         for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1049                 if (con_id && strcmp(con_id, "gpios"))
1050                         snprintf(propname, sizeof(propname), "%s-%s",
1051                                  con_id, gpio_suffixes[i]);
1052                 else
1053                         snprintf(propname, sizeof(propname), "%s",
1054                                  gpio_suffixes[i]);
1055
1056                 ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY,
1057                                             &obj);
1058                 if (ret == 0) {
1059                         if (obj->type == ACPI_TYPE_LOCAL_REFERENCE)
1060                                 count = 1;
1061                         else if (obj->type == ACPI_TYPE_PACKAGE)
1062                                 count = acpi_gpio_package_count(obj);
1063                 } else if (adev->driver_gpios) {
1064                         for (gm = adev->driver_gpios; gm->name; gm++)
1065                                 if (strcmp(propname, gm->name) == 0) {
1066                                         count = gm->size;
1067                                         break;
1068                                 }
1069                 }
1070                 if (count >= 0)
1071                         break;
1072         }
1073
1074         /* Then from plain _CRS GPIOs */
1075         if (count < 0) {
1076                 struct list_head resource_list;
1077                 unsigned int crs_count = 0;
1078
1079                 INIT_LIST_HEAD(&resource_list);
1080                 acpi_dev_get_resources(adev, &resource_list,
1081                                        acpi_find_gpio_count, &crs_count);
1082                 acpi_dev_free_resource_list(&resource_list);
1083                 if (crs_count > 0)
1084                         count = crs_count;
1085         }
1086         return count;
1087 }
1088
1089 struct acpi_crs_lookup {
1090         struct list_head node;
1091         struct acpi_device *adev;
1092         const char *con_id;
1093 };
1094
1095 static DEFINE_MUTEX(acpi_crs_lookup_lock);
1096 static LIST_HEAD(acpi_crs_lookup_list);
1097
1098 bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id)
1099 {
1100         struct acpi_crs_lookup *l, *lookup = NULL;
1101
1102         /* Never allow fallback if the device has properties */
1103         if (adev->data.properties || adev->driver_gpios)
1104                 return false;
1105
1106         mutex_lock(&acpi_crs_lookup_lock);
1107
1108         list_for_each_entry(l, &acpi_crs_lookup_list, node) {
1109                 if (l->adev == adev) {
1110                         lookup = l;
1111                         break;
1112                 }
1113         }
1114
1115         if (!lookup) {
1116                 lookup = kmalloc(sizeof(*lookup), GFP_KERNEL);
1117                 if (lookup) {
1118                         lookup->adev = adev;
1119                         lookup->con_id = kstrdup(con_id, GFP_KERNEL);
1120                         list_add_tail(&lookup->node, &acpi_crs_lookup_list);
1121                 }
1122         }
1123
1124         mutex_unlock(&acpi_crs_lookup_lock);
1125
1126         return lookup &&
1127                 ((!lookup->con_id && !con_id) ||
1128                  (lookup->con_id && con_id &&
1129                   strcmp(lookup->con_id, con_id) == 0));
1130 }