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         INIT_LIST_HEAD(&acpi_gpio->events);
 308         acpi_walk_resources(handle, "_AEI",
 309                             acpi_gpiochip_request_interrupt, acpi_gpio);
 310 }
 311 EXPORT_SYMBOL_GPL(acpi_gpiochip_request_interrupts);
 312
 313 /**
 314  * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
 315  * @chip:      GPIO chip
 316  *
 317  * Free interrupts associated with GPIO ACPI event method for the given
 318  * GPIO chip.
 319  */
 320 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
 321 {
 322         struct acpi_gpio_chip *acpi_gpio;
 323         struct acpi_gpio_event *event, *ep;
 324         acpi_handle handle;
 325         acpi_status status;
 326
 327         if (!chip->dev || !chip->to_irq)
 328                 return;
 329
 330         handle = ACPI_HANDLE(chip->dev);
 331         if (!handle)
 332                 return;
 333
 334         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 335         if (ACPI_FAILURE(status))
 336                 return;
 337
 338         list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
 339                 struct gpio_desc *desc;
 340
 341                 free_irq(event->irq, event);
 342                 desc = event->desc;
 343                 if (WARN_ON(IS_ERR(desc)))
 344                         continue;
 345                 gpiochip_unlock_as_irq(chip, event->pin);
 346                 gpiochip_free_own_desc(desc);
 347                 list_del(&event->node);
 348                 kfree(event);
 349         }
 350 }
 351 EXPORT_SYMBOL_GPL(acpi_gpiochip_free_interrupts);
 352
 353 int acpi_dev_add_driver_gpios(struct acpi_device *adev,
 354                               const struct acpi_gpio_mapping *gpios)
 355 {
 356         if (adev && gpios) {
 357                 adev->driver_gpios = gpios;
 358                 return 0;
 359         }
 360         return -EINVAL;
 361 }
 362 EXPORT_SYMBOL_GPL(acpi_dev_add_driver_gpios);
 363
 364 static bool acpi_get_driver_gpio_data(struct acpi_device *adev,
 365                                       const char *name, int index,
 366                                       struct acpi_reference_args *args)
 367 {
 368         const struct acpi_gpio_mapping *gm;
 369
 370         if (!adev->driver_gpios)
 371                 return false;
 372
 373         for (gm = adev->driver_gpios; gm->name; gm++)
 374                 if (!strcmp(name, gm->name) && gm->data && index < gm->size) {
 375                         const struct acpi_gpio_params *par = gm->data + index;
 376
 377                         args->adev = adev;
 378                         args->args[0] = par->crs_entry_index;
 379                         args->args[1] = par->line_index;
 380                         args->args[2] = par->active_low;
 381                         args->nargs = 3;
 382                         return true;
 383                 }
 384
 385         return false;
 386 }
 387
 388 struct acpi_gpio_lookup {
 389         struct acpi_gpio_info info;
 390         int index;
 391         int pin_index;
 392         struct gpio_desc *desc;
 393         int n;
 394 };
 395
 396 static int acpi_find_gpio(struct acpi_resource *ares, void *data)
 397 {
 398         struct acpi_gpio_lookup *lookup = data;
 399
 400         if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
 401                 return 1;
 402
 403         if (lookup->n++ == lookup->index && !lookup->desc) {
 404                 const struct acpi_resource_gpio *agpio = &ares->data.gpio;
 405                 int pin_index = lookup->pin_index;
 406
 407                 if (pin_index >= agpio->pin_table_length)
 408                         return 1;
 409
 410                 lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
 411                                               agpio->pin_table[pin_index]);
 412                 lookup->info.gpioint =
 413                         agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
 414
 415                 /*
 416                  * ActiveLow is only specified for GpioInt resource. If
 417                  * GpioIo is used then the only way to set the flag is
 418                  * to use _DSD "gpios" property.
 419                  */
 420                 if (lookup->info.gpioint)
 421                         lookup->info.active_low =
 422                                 agpio->polarity == ACPI_ACTIVE_LOW;
 423         }
 424
 425         return 1;
 426 }
 427
 428 /**
 429  * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
 430  * @adev: pointer to a ACPI device to get GPIO from
 431  * @propname: Property name of the GPIO (optional)
 432  * @index: index of GpioIo/GpioInt resource (starting from %0)
 433  * @info: info pointer to fill in (optional)
 434  *
 435  * Function goes through ACPI resources for @adev and based on @index looks
 436  * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
 437  * and returns it. @index matches GpioIo/GpioInt resources only so if there
 438  * are total %3 GPIO resources, the index goes from %0 to %2.
 439  *
 440  * If @propname is specified the GPIO is looked using device property. In
 441  * that case @index is used to select the GPIO entry in the property value
 442  * (in case of multiple).
 443  *
 444  * If the GPIO cannot be translated or there is an error an ERR_PTR is
 445  * returned.
 446  *
 447  * Note: if the GPIO resource has multiple entries in the pin list, this
 448  * function only returns the first.
 449  */
 450 struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
 451                                           const char *propname, int index,
 452                                           struct acpi_gpio_info *info)
 453 {
 454         struct acpi_gpio_lookup lookup;
 455         struct list_head resource_list;
 456         bool active_low = false;
 457         int ret;
 458
 459         if (!adev)
 460                 return ERR_PTR(-ENODEV);
 461
 462         memset(&lookup, 0, sizeof(lookup));
 463         lookup.index = index;
 464
 465         if (propname) {
 466                 struct acpi_reference_args args;
 467
 468                 dev_dbg(&adev->dev, "GPIO: looking up %s\n", propname);
 469
 470                 memset(&args, 0, sizeof(args));
 471                 ret = acpi_dev_get_property_reference(adev, propname,
 472                                                       index, &args);
 473                 if (ret) {
 474                         bool found = acpi_get_driver_gpio_data(adev, propname,
 475                                                                index, &args);
 476                         if (!found)
 477                                 return ERR_PTR(ret);
 478                 }
 479
 480                 /*
 481                  * The property was found and resolved so need to
 482                  * lookup the GPIO based on returned args instead.
 483                  */
 484                 adev = args.adev;
 485                 if (args.nargs >= 2) {
 486                         lookup.index = args.args[0];
 487                         lookup.pin_index = args.args[1];
 488                         /*
 489                          * 3rd argument, if present is used to
 490                          * specify active_low.
 491                          */
 492                         if (args.nargs >= 3)
 493                                 active_low = !!args.args[2];
 494                 }
 495
 496                 dev_dbg(&adev->dev, "GPIO: _DSD returned %s %zd %llu %llu %llu\n",
 497                         dev_name(&adev->dev), args.nargs,
 498                         args.args[0], args.args[1], args.args[2]);
 499         } else {
 500                 dev_dbg(&adev->dev, "GPIO: looking up %d in _CRS\n", index);
 501         }
 502
 503         INIT_LIST_HEAD(&resource_list);
 504         ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio,
 505                                      &lookup);
 506         if (ret < 0)
 507                 return ERR_PTR(ret);
 508
 509         acpi_dev_free_resource_list(&resource_list);
 510
 511         if (lookup.desc && info) {
 512                 *info = lookup.info;
 513                 if (active_low)
 514                         info->active_low = active_low;
 515         }
 516
 517         return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT);
 518 }
 519
 520 /**
 521  * acpi_dev_gpio_irq_get() - Find GpioInt and translate it to Linux IRQ number
 522  * @adev: pointer to a ACPI device to get IRQ from
 523  * @index: index of GpioInt resource (starting from %0)
 524  *
 525  * If the device has one or more GpioInt resources, this function can be
 526  * used to translate from the GPIO offset in the resource to the Linux IRQ
 527  * number.
 528  *
 529  * Return: Linux IRQ number (>%0) on success, negative errno on failure.
 530  */
 531 int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
 532 {
 533         int idx, i;
 534
 535         for (i = 0, idx = 0; idx <= index; i++) {
 536                 struct acpi_gpio_info info;
 537                 struct gpio_desc *desc;
 538
 539                 desc = acpi_get_gpiod_by_index(adev, NULL, i, &info);
 540                 if (IS_ERR(desc))
 541                         break;
 542                 if (info.gpioint && idx++ == index)
 543                         return gpiod_to_irq(desc);
 544         }
 545         return -ENOENT;
 546 }
 547 EXPORT_SYMBOL_GPL(acpi_dev_gpio_irq_get);
 548
 549 static acpi_status
 550 acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
 551                             u32 bits, u64 *value, void *handler_context,
 552                             void *region_context)
 553 {
 554         struct acpi_gpio_chip *achip = region_context;
 555         struct gpio_chip *chip = achip->chip;
 556         struct acpi_resource_gpio *agpio;
 557         struct acpi_resource *ares;
 558         int pin_index = (int)address;
 559         acpi_status status;
 560         bool pull_up;
 561         int length;
 562         int i;
 563
 564         status = acpi_buffer_to_resource(achip->conn_info.connection,
 565                                          achip->conn_info.length, &ares);
 566         if (ACPI_FAILURE(status))
 567                 return status;
 568
 569         if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) {
 570                 ACPI_FREE(ares);
 571                 return AE_BAD_PARAMETER;
 572         }
 573
 574         agpio = &ares->data.gpio;
 575         pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP;
 576
 577         if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT &&
 578             function == ACPI_WRITE)) {
 579                 ACPI_FREE(ares);
 580                 return AE_BAD_PARAMETER;
 581         }
 582
 583         length = min(agpio->pin_table_length, (u16)(pin_index + bits));
 584         for (i = pin_index; i < length; ++i) {
 585                 int pin = agpio->pin_table[i];
 586                 struct acpi_gpio_connection *conn;
 587                 struct gpio_desc *desc;
 588                 bool found;
 589
 590                 pin = acpi_gpiochip_pin_to_gpio_offset(chip, pin);
 591                 if (pin < 0) {
 592                         status = AE_BAD_PARAMETER;
 593                         goto out;
 594                 }
 595
 596                 mutex_lock(&achip->conn_lock);
 597
 598                 found = false;
 599                 list_for_each_entry(conn, &achip->conns, node) {
 600                         if (conn->pin == pin) {
 601                                 found = true;
 602                                 desc = conn->desc;
 603                                 break;
 604                         }
 605                 }
 606                 if (!found) {
 607                         desc = gpiochip_request_own_desc(chip, pin,
 608                                                          "ACPI:OpRegion");
 609                         if (IS_ERR(desc)) {
 610                                 status = AE_ERROR;
 611                                 mutex_unlock(&achip->conn_lock);
 612                                 goto out;
 613                         }
 614
 615                         switch (agpio->io_restriction) {
 616                         case ACPI_IO_RESTRICT_INPUT:
 617                                 gpiod_direction_input(desc);
 618                                 break;
 619                         case ACPI_IO_RESTRICT_OUTPUT:
 620                                 /*
 621                                  * ACPI GPIO resources don't contain an
 622                                  * initial value for the GPIO. Therefore we
 623                                  * deduce that value from the pull field
 624                                  * instead. If the pin is pulled up we
 625                                  * assume default to be high, otherwise
 626                                  * low.
 627                                  */
 628                                 gpiod_direction_output(desc, pull_up);
 629                                 break;
 630                         default:
 631                                 /*
 632                                  * Assume that the BIOS has configured the
 633                                  * direction and pull accordingly.
 634                                  */
 635                                 break;
 636                         }
 637
 638                         conn = kzalloc(sizeof(*conn), GFP_KERNEL);
 639                         if (!conn) {
 640                                 status = AE_NO_MEMORY;
 641                                 gpiochip_free_own_desc(desc);
 642                                 mutex_unlock(&achip->conn_lock);
 643                                 goto out;
 644                         }
 645
 646                         conn->pin = pin;
 647                         conn->desc = desc;
 648                         list_add_tail(&conn->node, &achip->conns);
 649                 }
 650
 651                 mutex_unlock(&achip->conn_lock);
 652
 653                 if (function == ACPI_WRITE)
 654                         gpiod_set_raw_value_cansleep(desc,
 655                                                      !!((1 << i) & *value));
 656                 else
 657                         *value |= (u64)gpiod_get_raw_value_cansleep(desc) << i;
 658         }
 659
 660 out:
 661         ACPI_FREE(ares);
 662         return status;
 663 }
 664
 665 static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip)
 666 {
 667         struct gpio_chip *chip = achip->chip;
 668         acpi_handle handle = ACPI_HANDLE(chip->dev);
 669         acpi_status status;
 670
 671         INIT_LIST_HEAD(&achip->conns);
 672         mutex_init(&achip->conn_lock);
 673         status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
 674                                                     acpi_gpio_adr_space_handler,
 675                                                     NULL, achip);
 676         if (ACPI_FAILURE(status))
 677                 dev_err(chip->dev, "Failed to install GPIO OpRegion handler\n");
 678 }
 679
 680 static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
 681 {
 682         struct gpio_chip *chip = achip->chip;
 683         acpi_handle handle = ACPI_HANDLE(chip->dev);
 684         struct acpi_gpio_connection *conn, *tmp;
 685         acpi_status status;
 686
 687         status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
 688                                                    acpi_gpio_adr_space_handler);
 689         if (ACPI_FAILURE(status)) {
 690                 dev_err(chip->dev, "Failed to remove GPIO OpRegion handler\n");
 691                 return;
 692         }
 693
 694         list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) {
 695                 gpiochip_free_own_desc(conn->desc);
 696                 list_del(&conn->node);
 697                 kfree(conn);
 698         }
 699 }
 700
 701 void acpi_gpiochip_add(struct gpio_chip *chip)
 702 {
 703         struct acpi_gpio_chip *acpi_gpio;
 704         acpi_handle handle;
 705         acpi_status status;
 706
 707         if (!chip || !chip->dev)
 708                 return;
 709
 710         handle = ACPI_HANDLE(chip->dev);
 711         if (!handle)
 712                 return;
 713
 714         acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
 715         if (!acpi_gpio) {
 716                 dev_err(chip->dev,
 717                         "Failed to allocate memory for ACPI GPIO chip\n");
 718                 return;
 719         }
 720
 721         acpi_gpio->chip = chip;
 722
 723         status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
 724         if (ACPI_FAILURE(status)) {
 725                 dev_err(chip->dev, "Failed to attach ACPI GPIO chip\n");
 726                 kfree(acpi_gpio);
 727                 return;
 728         }
 729
 730         acpi_gpiochip_request_regions(acpi_gpio);
 731 }
 732
 733 void acpi_gpiochip_remove(struct gpio_chip *chip)
 734 {
 735         struct acpi_gpio_chip *acpi_gpio;
 736         acpi_handle handle;
 737         acpi_status status;
 738
 739         if (!chip || !chip->dev)
 740                 return;
 741
 742         handle = ACPI_HANDLE(chip->dev);
 743         if (!handle)
 744                 return;
 745
 746         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 747         if (ACPI_FAILURE(status)) {
 748                 dev_warn(chip->dev, "Failed to retrieve ACPI GPIO chip\n");
 749                 return;
 750         }
 751
 752         acpi_gpiochip_free_regions(acpi_gpio);
 753
 754         acpi_detach_data(handle, acpi_gpio_chip_dh);
 755         kfree(acpi_gpio);
 756 }
 757
 758 static unsigned int acpi_gpio_package_count(const union acpi_object *obj)
 759 {
 760         const union acpi_object *element = obj->package.elements;
 761         const union acpi_object *end = element + obj->package.count;
 762         unsigned int count = 0;
 763
 764         while (element < end) {
 765                 if (element->type == ACPI_TYPE_LOCAL_REFERENCE)
 766                         count++;
 767
 768                 element++;
 769         }
 770         return count;
 771 }
 772
 773 static int acpi_find_gpio_count(struct acpi_resource *ares, void *data)
 774 {
 775         unsigned int *count = data;
 776
 777         if (ares->type == ACPI_RESOURCE_TYPE_GPIO)
 778                 *count += ares->data.gpio.pin_table_length;
 779
 780         return 1;
 781 }
 782
 783 /**
 784  * acpi_gpio_count - return the number of GPIOs associated with a
 785  *              device / function or -ENOENT if no GPIO has been
 786  *              assigned to the requested function.
 787  * @dev:        GPIO consumer, can be NULL for system-global GPIOs
 788  * @con_id:     function within the GPIO consumer
 789  */
 790 int acpi_gpio_count(struct device *dev, const char *con_id)
 791 {
 792         struct acpi_device *adev = ACPI_COMPANION(dev);
 793         const union acpi_object *obj;
 794         const struct acpi_gpio_mapping *gm;
 795         int count = -ENOENT;
 796         int ret;
 797         char propname[32];
 798         unsigned int i;
 799
 800         /* Try first from _DSD */
 801         for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
 802                 if (con_id && strcmp(con_id, "gpios"))
 803                         snprintf(propname, sizeof(propname), "%s-%s",
 804                                  con_id, gpio_suffixes[i]);
 805                 else
 806                         snprintf(propname, sizeof(propname), "%s",
 807                                  gpio_suffixes[i]);
 808
 809                 ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY,
 810                                             &obj);
 811                 if (ret == 0) {
 812                         if (obj->type == ACPI_TYPE_LOCAL_REFERENCE)
 813                                 count = 1;
 814                         else if (obj->type == ACPI_TYPE_PACKAGE)
 815                                 count = acpi_gpio_package_count(obj);
 816                 } else if (adev->driver_gpios) {
 817                         for (gm = adev->driver_gpios; gm->name; gm++)
 818                                 if (strcmp(propname, gm->name) == 0) {
 819                                         count = gm->size;
 820                                         break;
 821                                 }
 822                 }
 823                 if (count >= 0)
 824                         break;
 825         }
 826
 827         /* Then from plain _CRS GPIOs */
 828         if (count < 0) {
 829                 struct list_head resource_list;
 830                 unsigned int crs_count = 0;
 831
 832                 INIT_LIST_HEAD(&resource_list);
 833                 acpi_dev_get_resources(adev, &resource_list,
 834                                        acpi_find_gpio_count, &crs_count);
 835                 acpi_dev_free_resource_list(&resource_list);
 836                 if (crs_count > 0)
 837                         count = crs_count;
 838         }
 839         return count;
 840 }