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->dev)
  55                 return false;
  56
  57         return ACPI_HANDLE(gc->dev) == 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_chip *chip, 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(&chip->pin_ranges))
  80                 return pin;
  81
  82         list_for_each_entry(pin_range, &chip->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 - chip->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 - chip->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_chip *chip,
 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, 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->dev);
 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, 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->dev, "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->dev, "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->dev, "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->dev, "Failed to setup interrupt handler for %d\n",
 263                         event->irq);
 264                 goto fail_free_event;
 265         }
 266
 267         list_add_tail(&event->node, &acpi_gpio->events);
 268         return AE_OK;
 269
 270 fail_free_event:
 271         kfree(event);
 272 fail_unlock_irq:
 273         gpiochip_unlock_as_irq(chip, pin);
 274 fail_free_desc:
 275         gpiochip_free_own_desc(desc);
 276
 277         return AE_ERROR;
 278 }
 279
 280 /**
 281  * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
 282  * @chip:      GPIO chip
 283  *
 284  * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
 285  * handled by ACPI event methods which need to be called from the GPIO
 286  * chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
 287  * gpio pins have acpi event methods and assigns interrupt handlers that calls
 288  * the acpi event methods for those pins.
 289  */
 290 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
 291 {
 292         struct acpi_gpio_chip *acpi_gpio;
 293         acpi_handle handle;
 294         acpi_status status;
 295
 296         if (!chip->dev || !chip->to_irq)
 297                 return;
 298
 299         handle = ACPI_HANDLE(chip->dev);
 300         if (!handle)
 301                 return;
 302
 303         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 304         if (ACPI_FAILURE(status))
 305                 return;
 306
 307         acpi_walk_resources(handle, "_AEI",
 308                             acpi_gpiochip_request_interrupt, acpi_gpio);
 309 }
 310 EXPORT_SYMBOL_GPL(acpi_gpiochip_request_interrupts);
 311
 312 /**
 313  * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
 314  * @chip:      GPIO chip
 315  *
 316  * Free interrupts associated with GPIO ACPI event method for the given
 317  * GPIO chip.
 318  */
 319 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
 320 {
 321         struct acpi_gpio_chip *acpi_gpio;
 322         struct acpi_gpio_event *event, *ep;
 323         acpi_handle handle;
 324         acpi_status status;
 325
 326         if (!chip->dev || !chip->to_irq)
 327                 return;
 328
 329         handle = ACPI_HANDLE(chip->dev);
 330         if (!handle)
 331                 return;
 332
 333         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 334         if (ACPI_FAILURE(status))
 335                 return;
 336
 337         list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
 338                 struct gpio_desc *desc;
 339
 340                 free_irq(event->irq, event);
 341                 desc = event->desc;
 342                 if (WARN_ON(IS_ERR(desc)))
 343                         continue;
 344                 gpiochip_unlock_as_irq(chip, event->pin);
 345                 gpiochip_free_own_desc(desc);
 346                 list_del(&event->node);
 347                 kfree(event);
 348         }
 349 }
 350 EXPORT_SYMBOL_GPL(acpi_gpiochip_free_interrupts);
 351
 352 int acpi_dev_add_driver_gpios(struct acpi_device *adev,
 353                               const struct acpi_gpio_mapping *gpios)
 354 {
 355         if (adev && gpios) {
 356                 adev->driver_gpios = gpios;
 357                 return 0;
 358         }
 359         return -EINVAL;
 360 }
 361 EXPORT_SYMBOL_GPL(acpi_dev_add_driver_gpios);
 362
 363 static bool acpi_get_driver_gpio_data(struct acpi_device *adev,
 364                                       const char *name, int index,
 365                                       struct acpi_reference_args *args)
 366 {
 367         const struct acpi_gpio_mapping *gm;
 368
 369         if (!adev->driver_gpios)
 370                 return false;
 371
 372         for (gm = adev->driver_gpios; gm->name; gm++)
 373                 if (!strcmp(name, gm->name) && gm->data && index < gm->size) {
 374                         const struct acpi_gpio_params *par = gm->data + index;
 375
 376                         args->adev = adev;
 377                         args->args[0] = par->crs_entry_index;
 378                         args->args[1] = par->line_index;
 379                         args->args[2] = par->active_low;
 380                         args->nargs = 3;
 381                         return true;
 382                 }
 383
 384         return false;
 385 }
 386
 387 struct acpi_gpio_lookup {
 388         struct acpi_gpio_info info;
 389         int index;
 390         int pin_index;
 391         bool active_low;
 392         struct acpi_device *adev;
 393         struct gpio_desc *desc;
 394         int n;
 395 };
 396
 397 static int acpi_find_gpio(struct acpi_resource *ares, void *data)
 398 {
 399         struct acpi_gpio_lookup *lookup = data;
 400
 401         if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
 402                 return 1;
 403
 404         if (lookup->n++ == lookup->index && !lookup->desc) {
 405                 const struct acpi_resource_gpio *agpio = &ares->data.gpio;
 406                 int pin_index = lookup->pin_index;
 407
 408                 if (pin_index >= agpio->pin_table_length)
 409                         return 1;
 410
 411                 lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
 412                                               agpio->pin_table[pin_index]);
 413                 lookup->info.gpioint =
 414                         agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
 415
 416                 /*
 417                  * ActiveLow is only specified for GpioInt resource. If
 418                  * GpioIo is used then the only way to set the flag is
 419                  * to use _DSD "gpios" property.
 420                  * Note: we expect here:
 421                  * - ACPI_ACTIVE_LOW == GPIO_ACTIVE_LOW
 422                  * - ACPI_ACTIVE_HIGH == GPIO_ACTIVE_HIGH
 423                  */
 424                 if (lookup->info.gpioint) {
 425                         lookup->info.polarity = agpio->polarity;
 426                         lookup->info.triggering = agpio->triggering;
 427                 }
 428
 429         }
 430
 431         return 1;
 432 }
 433
 434 static int acpi_gpio_resource_lookup(struct acpi_gpio_lookup *lookup,
 435                                      struct acpi_gpio_info *info)
 436 {
 437         struct list_head res_list;
 438         int ret;
 439
 440         INIT_LIST_HEAD(&res_list);
 441
 442         ret = acpi_dev_get_resources(lookup->adev, &res_list, acpi_find_gpio,
 443                                      lookup);
 444         if (ret < 0)
 445                 return ret;
 446
 447         acpi_dev_free_resource_list(&res_list);
 448
 449         if (!lookup->desc)
 450                 return -ENOENT;
 451
 452         if (info) {
 453                 *info = lookup->info;
 454                 if (lookup->active_low)
 455                         info->polarity = lookup->active_low;
 456         }
 457         return 0;
 458 }
 459
 460 static int acpi_gpio_property_lookup(struct fwnode_handle *fwnode,
 461                                      const char *propname, int index,
 462                                      struct acpi_gpio_lookup *lookup)
 463 {
 464         struct acpi_reference_args args;
 465         int ret;
 466
 467         memset(&args, 0, sizeof(args));
 468         ret = acpi_node_get_property_reference(fwnode, propname, index, &args);
 469         if (ret) {
 470                 struct acpi_device *adev = to_acpi_device_node(fwnode);
 471
 472                 if (!adev)
 473                         return ret;
 474
 475                 if (!acpi_get_driver_gpio_data(adev, propname, index, &args))
 476                         return ret;
 477         }
 478         /*
 479          * The property was found and resolved, so need to lookup the GPIO based
 480          * on returned args.
 481          */
 482         lookup->adev = args.adev;
 483         if (args.nargs >= 2) {
 484                 lookup->index = args.args[0];
 485                 lookup->pin_index = args.args[1];
 486                 /* 3rd argument, if present is used to specify active_low. */
 487                 if (args.nargs >= 3)
 488                         lookup->active_low = !!args.args[2];
 489         }
 490         return 0;
 491 }
 492
 493 /**
 494  * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
 495  * @adev: pointer to a ACPI device to get GPIO from
 496  * @propname: Property name of the GPIO (optional)
 497  * @index: index of GpioIo/GpioInt resource (starting from %0)
 498  * @info: info pointer to fill in (optional)
 499  *
 500  * Function goes through ACPI resources for @adev and based on @index looks
 501  * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
 502  * and returns it. @index matches GpioIo/GpioInt resources only so if there
 503  * are total %3 GPIO resources, the index goes from %0 to %2.
 504  *
 505  * If @propname is specified the GPIO is looked using device property. In
 506  * that case @index is used to select the GPIO entry in the property value
 507  * (in case of multiple).
 508  *
 509  * If the GPIO cannot be translated or there is an error an ERR_PTR is
 510  * returned.
 511  *
 512  * Note: if the GPIO resource has multiple entries in the pin list, this
 513  * function only returns the first.
 514  */
 515 struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
 516                                           const char *propname, int index,
 517                                           struct acpi_gpio_info *info)
 518 {
 519         struct acpi_gpio_lookup lookup;
 520         int ret;
 521
 522         if (!adev)
 523                 return ERR_PTR(-ENODEV);
 524
 525         memset(&lookup, 0, sizeof(lookup));
 526         lookup.index = index;
 527
 528         if (propname) {
 529                 dev_dbg(&adev->dev, "GPIO: looking up %s\n", propname);
 530
 531                 ret = acpi_gpio_property_lookup(acpi_fwnode_handle(adev),
 532                                                 propname, index, &lookup);
 533                 if (ret)
 534                         return ERR_PTR(ret);
 535
 536                 dev_dbg(&adev->dev, "GPIO: _DSD returned %s %d %d %u\n",
 537                         dev_name(&lookup.adev->dev), lookup.index,
 538                         lookup.pin_index, lookup.active_low);
 539         } else {
 540                 dev_dbg(&adev->dev, "GPIO: looking up %d in _CRS\n", index);
 541                 lookup.adev = adev;
 542         }
 543
 544         ret = acpi_gpio_resource_lookup(&lookup, info);
 545         return ret ? ERR_PTR(ret) : lookup.desc;
 546 }
 547
 548 /**
 549  * acpi_node_get_gpiod() - get a GPIO descriptor from ACPI resources
 550  * @fwnode: pointer to an ACPI firmware node to get the GPIO information from
 551  * @propname: Property name of the GPIO
 552  * @index: index of GpioIo/GpioInt resource (starting from %0)
 553  * @info: info pointer to fill in (optional)
 554  *
 555  * If @fwnode is an ACPI device object, call %acpi_get_gpiod_by_index() for it.
 556  * Otherwise (ie. it is a data-only non-device object), use the property-based
 557  * GPIO lookup to get to the GPIO resource with the relevant information and use
 558  * that to obtain the GPIO descriptor to return.
 559  */
 560 struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
 561                                       const char *propname, int index,
 562                                       struct acpi_gpio_info *info)
 563 {
 564         struct acpi_gpio_lookup lookup;
 565         struct acpi_device *adev;
 566         int ret;
 567
 568         adev = to_acpi_device_node(fwnode);
 569         if (adev)
 570                 return acpi_get_gpiod_by_index(adev, propname, index, info);
 571
 572         if (!is_acpi_data_node(fwnode))
 573                 return ERR_PTR(-ENODEV);
 574
 575         if (!propname)
 576                 return ERR_PTR(-EINVAL);
 577
 578         memset(&lookup, 0, sizeof(lookup));
 579         lookup.index = index;
 580
 581         ret = acpi_gpio_property_lookup(fwnode, propname, index, &lookup);
 582         if (ret)
 583                 return ERR_PTR(ret);
 584
 585         ret = acpi_gpio_resource_lookup(&lookup, info);
 586         return ret ? ERR_PTR(ret) : lookup.desc;
 587 }
 588
 589 /**
 590  * acpi_dev_gpio_irq_get() - Find GpioInt and translate it to Linux IRQ number
 591  * @adev: pointer to a ACPI device to get IRQ from
 592  * @index: index of GpioInt resource (starting from %0)
 593  *
 594  * If the device has one or more GpioInt resources, this function can be
 595  * used to translate from the GPIO offset in the resource to the Linux IRQ
 596  * number.
 597  *
 598  * Return: Linux IRQ number (>%0) on success, negative errno on failure.
 599  */
 600 int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
 601 {
 602         int idx, i;
 603         unsigned int irq_flags;
 604
 605         for (i = 0, idx = 0; idx <= index; i++) {
 606                 struct acpi_gpio_info info;
 607                 struct gpio_desc *desc;
 608
 609                 desc = acpi_get_gpiod_by_index(adev, NULL, i, &info);
 610                 if (IS_ERR(desc))
 611                         break;
 612                 if (info.gpioint && idx++ == index) {
 613                         int irq = gpiod_to_irq(desc);
 614
 615                         if (irq < 0)
 616                                 return irq;
 617
 618                         irq_flags = acpi_dev_get_irq_type(info.triggering,
 619                                                           info.polarity);
 620
 621                         /* Set type if specified and different than the current one */
 622                         if (irq_flags != IRQ_TYPE_NONE &&
 623                             irq_flags != irq_get_trigger_type(irq))
 624                                 irq_set_irq_type(irq, irq_flags);
 625
 626                         return irq;
 627                 }
 628
 629         }
 630         return -ENOENT;
 631 }
 632 EXPORT_SYMBOL_GPL(acpi_dev_gpio_irq_get);
 633
 634 static acpi_status
 635 acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
 636                             u32 bits, u64 *value, void *handler_context,
 637                             void *region_context)
 638 {
 639         struct acpi_gpio_chip *achip = region_context;
 640         struct gpio_chip *chip = achip->chip;
 641         struct acpi_resource_gpio *agpio;
 642         struct acpi_resource *ares;
 643         int pin_index = (int)address;
 644         acpi_status status;
 645         bool pull_up;
 646         int length;
 647         int i;
 648
 649         status = acpi_buffer_to_resource(achip->conn_info.connection,
 650                                          achip->conn_info.length, &ares);
 651         if (ACPI_FAILURE(status))
 652                 return status;
 653
 654         if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) {
 655                 ACPI_FREE(ares);
 656                 return AE_BAD_PARAMETER;
 657         }
 658
 659         agpio = &ares->data.gpio;
 660         pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP;
 661
 662         if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT &&
 663             function == ACPI_WRITE)) {
 664                 ACPI_FREE(ares);
 665                 return AE_BAD_PARAMETER;
 666         }
 667
 668         length = min(agpio->pin_table_length, (u16)(pin_index + bits));
 669         for (i = pin_index; i < length; ++i) {
 670                 int pin = agpio->pin_table[i];
 671                 struct acpi_gpio_connection *conn;
 672                 struct gpio_desc *desc;
 673                 bool found;
 674
 675                 pin = acpi_gpiochip_pin_to_gpio_offset(chip, pin);
 676                 if (pin < 0) {
 677                         status = AE_BAD_PARAMETER;
 678                         goto out;
 679                 }
 680
 681                 mutex_lock(&achip->conn_lock);
 682
 683                 found = false;
 684                 list_for_each_entry(conn, &achip->conns, node) {
 685                         if (conn->pin == pin) {
 686                                 found = true;
 687                                 desc = conn->desc;
 688                                 break;
 689                         }
 690                 }
 691
 692                 /*
 693                  * The same GPIO can be shared between operation region and
 694                  * event but only if the access here is ACPI_READ. In that
 695                  * case we "borrow" the event GPIO instead.
 696                  */
 697                 if (!found && agpio->sharable == ACPI_SHARED &&
 698                      function == ACPI_READ) {
 699                         struct acpi_gpio_event *event;
 700
 701                         list_for_each_entry(event, &achip->events, node) {
 702                                 if (event->pin == pin) {
 703                                         desc = event->desc;
 704                                         found = true;
 705                                         break;
 706                                 }
 707                         }
 708                 }
 709
 710                 if (!found) {
 711                         desc = gpiochip_request_own_desc(chip, pin,
 712                                                          "ACPI:OpRegion");
 713                         if (IS_ERR(desc)) {
 714                                 status = AE_ERROR;
 715                                 mutex_unlock(&achip->conn_lock);
 716                                 goto out;
 717                         }
 718
 719                         switch (agpio->io_restriction) {
 720                         case ACPI_IO_RESTRICT_INPUT:
 721                                 gpiod_direction_input(desc);
 722                                 break;
 723                         case ACPI_IO_RESTRICT_OUTPUT:
 724                                 /*
 725                                  * ACPI GPIO resources don't contain an
 726                                  * initial value for the GPIO. Therefore we
 727                                  * deduce that value from the pull field
 728                                  * instead. If the pin is pulled up we
 729                                  * assume default to be high, otherwise
 730                                  * low.
 731                                  */
 732                                 gpiod_direction_output(desc, pull_up);
 733                                 break;
 734                         default:
 735                                 /*
 736                                  * Assume that the BIOS has configured the
 737                                  * direction and pull accordingly.
 738                                  */
 739                                 break;
 740                         }
 741
 742                         conn = kzalloc(sizeof(*conn), GFP_KERNEL);
 743                         if (!conn) {
 744                                 status = AE_NO_MEMORY;
 745                                 gpiochip_free_own_desc(desc);
 746                                 mutex_unlock(&achip->conn_lock);
 747                                 goto out;
 748                         }
 749
 750                         conn->pin = pin;
 751                         conn->desc = desc;
 752                         list_add_tail(&conn->node, &achip->conns);
 753                 }
 754
 755                 mutex_unlock(&achip->conn_lock);
 756
 757                 if (function == ACPI_WRITE)
 758                         gpiod_set_raw_value_cansleep(desc,
 759                                                      !!((1 << i) & *value));
 760                 else
 761                         *value |= (u64)gpiod_get_raw_value_cansleep(desc) << i;
 762         }
 763
 764 out:
 765         ACPI_FREE(ares);
 766         return status;
 767 }
 768
 769 static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip)
 770 {
 771         struct gpio_chip *chip = achip->chip;
 772         acpi_handle handle = ACPI_HANDLE(chip->dev);
 773         acpi_status status;
 774
 775         INIT_LIST_HEAD(&achip->conns);
 776         mutex_init(&achip->conn_lock);
 777         status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
 778                                                     acpi_gpio_adr_space_handler,
 779                                                     NULL, achip);
 780         if (ACPI_FAILURE(status))
 781                 dev_err(chip->dev, "Failed to install GPIO OpRegion handler\n");
 782 }
 783
 784 static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
 785 {
 786         struct gpio_chip *chip = achip->chip;
 787         acpi_handle handle = ACPI_HANDLE(chip->dev);
 788         struct acpi_gpio_connection *conn, *tmp;
 789         acpi_status status;
 790
 791         status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
 792                                                    acpi_gpio_adr_space_handler);
 793         if (ACPI_FAILURE(status)) {
 794                 dev_err(chip->dev, "Failed to remove GPIO OpRegion handler\n");
 795                 return;
 796         }
 797
 798         list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) {
 799                 gpiochip_free_own_desc(conn->desc);
 800                 list_del(&conn->node);
 801                 kfree(conn);
 802         }
 803 }
 804
 805 void acpi_gpiochip_add(struct gpio_chip *chip)
 806 {
 807         struct acpi_gpio_chip *acpi_gpio;
 808         acpi_handle handle;
 809         acpi_status status;
 810
 811         if (!chip || !chip->dev)
 812                 return;
 813
 814         handle = ACPI_HANDLE(chip->dev);
 815         if (!handle)
 816                 return;
 817
 818         acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
 819         if (!acpi_gpio) {
 820                 dev_err(chip->dev,
 821                         "Failed to allocate memory for ACPI GPIO chip\n");
 822                 return;
 823         }
 824
 825         acpi_gpio->chip = chip;
 826         INIT_LIST_HEAD(&acpi_gpio->events);
 827
 828         status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
 829         if (ACPI_FAILURE(status)) {
 830                 dev_err(chip->dev, "Failed to attach ACPI GPIO chip\n");
 831                 kfree(acpi_gpio);
 832                 return;
 833         }
 834
 835         acpi_gpiochip_request_regions(acpi_gpio);
 836 }
 837
 838 void acpi_gpiochip_remove(struct gpio_chip *chip)
 839 {
 840         struct acpi_gpio_chip *acpi_gpio;
 841         acpi_handle handle;
 842         acpi_status status;
 843
 844         if (!chip || !chip->dev)
 845                 return;
 846
 847         handle = ACPI_HANDLE(chip->dev);
 848         if (!handle)
 849                 return;
 850
 851         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 852         if (ACPI_FAILURE(status)) {
 853                 dev_warn(chip->dev, "Failed to retrieve ACPI GPIO chip\n");
 854                 return;
 855         }
 856
 857         acpi_gpiochip_free_regions(acpi_gpio);
 858
 859         acpi_detach_data(handle, acpi_gpio_chip_dh);
 860         kfree(acpi_gpio);
 861 }
 862
 863 static unsigned int acpi_gpio_package_count(const union acpi_object *obj)
 864 {
 865         const union acpi_object *element = obj->package.elements;
 866         const union acpi_object *end = element + obj->package.count;
 867         unsigned int count = 0;
 868
 869         while (element < end) {
 870                 if (element->type == ACPI_TYPE_LOCAL_REFERENCE)
 871                         count++;
 872
 873                 element++;
 874         }
 875         return count;
 876 }
 877
 878 static int acpi_find_gpio_count(struct acpi_resource *ares, void *data)
 879 {
 880         unsigned int *count = data;
 881
 882         if (ares->type == ACPI_RESOURCE_TYPE_GPIO)
 883                 *count += ares->data.gpio.pin_table_length;
 884
 885         return 1;
 886 }
 887
 888 /**
 889  * acpi_gpio_count - return the number of GPIOs associated with a
 890  *              device / function or -ENOENT if no GPIO has been
 891  *              assigned to the requested function.
 892  * @dev:        GPIO consumer, can be NULL for system-global GPIOs
 893  * @con_id:     function within the GPIO consumer
 894  */
 895 int acpi_gpio_count(struct device *dev, const char *con_id)
 896 {
 897         struct acpi_device *adev = ACPI_COMPANION(dev);
 898         const union acpi_object *obj;
 899         const struct acpi_gpio_mapping *gm;
 900         int count = -ENOENT;
 901         int ret;
 902         char propname[32];
 903         unsigned int i;
 904
 905         /* Try first from _DSD */
 906         for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
 907                 if (con_id && strcmp(con_id, "gpios"))
 908                         snprintf(propname, sizeof(propname), "%s-%s",
 909                                  con_id, gpio_suffixes[i]);
 910                 else
 911                         snprintf(propname, sizeof(propname), "%s",
 912                                  gpio_suffixes[i]);
 913
 914                 ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY,
 915                                             &obj);
 916                 if (ret == 0) {
 917                         if (obj->type == ACPI_TYPE_LOCAL_REFERENCE)
 918                                 count = 1;
 919                         else if (obj->type == ACPI_TYPE_PACKAGE)
 920                                 count = acpi_gpio_package_count(obj);
 921                 } else if (adev->driver_gpios) {
 922                         for (gm = adev->driver_gpios; gm->name; gm++)
 923                                 if (strcmp(propname, gm->name) == 0) {
 924                                         count = gm->size;
 925                                         break;
 926                                 }
 927                 }
 928                 if (count >= 0)
 929                         break;
 930         }
 931
 932         /* Then from plain _CRS GPIOs */
 933         if (count < 0) {
 934                 struct list_head resource_list;
 935                 unsigned int crs_count = 0;
 936
 937                 INIT_LIST_HEAD(&resource_list);
 938                 acpi_dev_get_resources(adev, &resource_list,
 939                                        acpi_find_gpio_count, &crs_count);
 940                 acpi_dev_free_resource_list(&resource_list);
 941                 if (crs_count > 0)
 942                         count = crs_count;
 943         }
 944         return count;
 945 }
 946
 947 struct acpi_crs_lookup {
 948         struct list_head node;
 949         struct acpi_device *adev;
 950         const char *con_id;
 951 };
 952
 953 static DEFINE_MUTEX(acpi_crs_lookup_lock);
 954 static LIST_HEAD(acpi_crs_lookup_list);
 955
 956 bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id)
 957 {
 958         struct acpi_crs_lookup *l, *lookup = NULL;
 959
 960         /* Never allow fallback if the device has properties */
 961         if (adev->data.properties || adev->driver_gpios)
 962                 return false;
 963
 964         mutex_lock(&acpi_crs_lookup_lock);
 965
 966         list_for_each_entry(l, &acpi_crs_lookup_list, node) {
 967                 if (l->adev == adev) {
 968                         lookup = l;
 969                         break;
 970                 }
 971         }
 972
 973         if (!lookup) {
 974                 lookup = kmalloc(sizeof(*lookup), GFP_KERNEL);
 975                 if (lookup) {
 976                         lookup->adev = adev;
 977                         lookup->con_id = con_id;
 978                         list_add_tail(&lookup->node, &acpi_crs_lookup_list);
 979                 }
 980         }
 981
 982         mutex_unlock(&acpi_crs_lookup_lock);
 983
 984         return lookup &&
 985                 ((!lookup->con_id && !con_id) ||
 986                  (lookup->con_id && con_id &&
 987                   strcmp(lookup->con_id, con_id) == 0));
 988 }