drivers/gpio/gpiolib-acpi.c

   1 /*
   2  * ACPI helpers for GPIO API
   3  *
   4  * Copyright (C) 2012, Intel Corporation
   5  * Authors: Mathias Nyman <mathias.nyman@linux.intel.com>
   6  *          Mika Westerberg <mika.westerberg@linux.intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/errno.h>
  14 #include <linux/gpio.h>
  15 #include <linux/gpio/consumer.h>
  16 #include <linux/gpio/driver.h>
  17 #include <linux/gpio/machine.h>
  18 #include <linux/export.h>
  19 #include <linux/acpi.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/mutex.h>
  22 #include <linux/pinctrl/pinctrl.h>
  23
  24 #include "gpiolib.h"
  25
  26 struct acpi_gpio_event {
  27         struct list_head node;
  28         acpi_handle handle;
  29         unsigned int pin;
  30         unsigned int irq;
  31         struct gpio_desc *desc;
  32 };
  33
  34 struct acpi_gpio_connection {
  35         struct list_head node;
  36         unsigned int pin;
  37         struct gpio_desc *desc;
  38 };
  39
  40 struct acpi_gpio_chip {
  41         /*
  42          * ACPICA requires that the first field of the context parameter
  43          * passed to acpi_install_address_space_handler() is large enough
  44          * to hold struct acpi_connection_info.
  45          */
  46         struct acpi_connection_info conn_info;
  47         struct list_head conns;
  48         struct mutex conn_lock;
  49         struct gpio_chip *chip;
  50         struct list_head events;
  51 };
  52
  53 static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
  54 {
  55         if (!gc->parent)
  56                 return false;
  57
  58         return ACPI_HANDLE(gc->parent) == data;
  59 }
  60
  61 #ifdef CONFIG_PINCTRL
  62 /**
  63  * acpi_gpiochip_pin_to_gpio_offset() - translates ACPI GPIO to Linux GPIO
  64  * @chip: GPIO chip
  65  * @pin: ACPI GPIO pin number from GpioIo/GpioInt resource
  66  *
  67  * Function takes ACPI GpioIo/GpioInt pin number as a parameter and
  68  * translates it to a corresponding offset suitable to be passed to a
  69  * GPIO controller driver.
  70  *
  71  * Typically the returned offset is same as @pin, but if the GPIO
  72  * controller uses pin controller and the mapping is not contiguous the
  73  * offset might be different.
  74  */
  75 static int acpi_gpiochip_pin_to_gpio_offset(struct gpio_device *gdev, int pin)
  76 {
  77         struct gpio_pin_range *pin_range;
  78
  79         /* If there are no ranges in this chip, use 1:1 mapping */
  80         if (list_empty(&gdev->pin_ranges))
  81                 return pin;
  82
  83         list_for_each_entry(pin_range, &gdev->pin_ranges, node) {
  84                 const struct pinctrl_gpio_range *range = &pin_range->range;
  85                 int i;
  86
  87                 if (range->pins) {
  88                         for (i = 0; i < range->npins; i++) {
  89                                 if (range->pins[i] == pin)
  90                                         return range->base + i - gdev->base;
  91                         }
  92                 } else {
  93                         if (pin >= range->pin_base &&
  94                             pin < range->pin_base + range->npins) {
  95                                 unsigned gpio_base;
  96
  97                                 gpio_base = range->base - gdev->base;
  98                                 return gpio_base + pin - range->pin_base;
  99                         }
 100                 }
 101         }
 102
 103         return -EINVAL;
 104 }
 105 #else
 106 static inline int acpi_gpiochip_pin_to_gpio_offset(struct gpio_device *gdev,
 107                                                    int pin)
 108 {
 109         return pin;
 110 }
 111 #endif
 112
 113 /**
 114  * acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API
 115  * @path:       ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
 116  * @pin:        ACPI GPIO pin number (0-based, controller-relative)
 117  *
 118  * Return: GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR
 119  * error value. Specifically returns %-EPROBE_DEFER if the referenced GPIO
 120  * controller does not have gpiochip registered at the moment. This is to
 121  * support probe deferral.
 122  */
 123 static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
 124 {
 125         struct gpio_chip *chip;
 126         acpi_handle handle;
 127         acpi_status status;
 128         int offset;
 129
 130         status = acpi_get_handle(NULL, path, &handle);
 131         if (ACPI_FAILURE(status))
 132                 return ERR_PTR(-ENODEV);
 133
 134         chip = gpiochip_find(handle, acpi_gpiochip_find);
 135         if (!chip)
 136                 return ERR_PTR(-EPROBE_DEFER);
 137
 138         offset = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, pin);
 139         if (offset < 0)
 140                 return ERR_PTR(offset);
 141
 142         return gpiochip_get_desc(chip, offset);
 143 }
 144
 145 static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
 146 {
 147         struct acpi_gpio_event *event = data;
 148
 149         acpi_evaluate_object(event->handle, NULL, NULL, NULL);
 150
 151         return IRQ_HANDLED;
 152 }
 153
 154 static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
 155 {
 156         struct acpi_gpio_event *event = data;
 157
 158         acpi_execute_simple_method(event->handle, NULL, event->pin);
 159
 160         return IRQ_HANDLED;
 161 }
 162
 163 static void acpi_gpio_chip_dh(acpi_handle handle, void *data)
 164 {
 165         /* The address of this function is used as a key. */
 166 }
 167
 168 static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
 169                                                    void *context)
 170 {
 171         struct acpi_gpio_chip *acpi_gpio = context;
 172         struct gpio_chip *chip = acpi_gpio->chip;
 173         struct acpi_resource_gpio *agpio;
 174         acpi_handle handle, evt_handle;
 175         struct acpi_gpio_event *event;
 176         irq_handler_t handler = NULL;
 177         struct gpio_desc *desc;
 178         unsigned long irqflags;
 179         int ret, pin, irq;
 180
 181         if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
 182                 return AE_OK;
 183
 184         agpio = &ares->data.gpio;
 185         if (agpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT)
 186                 return AE_OK;
 187
 188         handle = ACPI_HANDLE(chip->parent);
 189         pin = agpio->pin_table[0];
 190
 191         if (pin <= 255) {
 192                 char ev_name[5];
 193                 sprintf(ev_name, "_%c%02X",
 194                         agpio->triggering == ACPI_EDGE_SENSITIVE ? 'E' : 'L',
 195                         pin);
 196                 if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
 197                         handler = acpi_gpio_irq_handler;
 198         }
 199         if (!handler) {
 200                 if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
 201                         handler = acpi_gpio_irq_handler_evt;
 202         }
 203         if (!handler)
 204                 return AE_BAD_PARAMETER;
 205
 206         pin = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, pin);
 207         if (pin < 0)
 208                 return AE_BAD_PARAMETER;
 209
 210         desc = gpiochip_request_own_desc(chip, pin, "ACPI:Event");
 211         if (IS_ERR(desc)) {
 212                 dev_err(chip->parent, "Failed to request GPIO\n");
 213                 return AE_ERROR;
 214         }
 215
 216         gpiod_direction_input(desc);
 217
 218         ret = gpiochip_lock_as_irq(chip, pin);
 219         if (ret) {
 220                 dev_err(chip->parent, "Failed to lock GPIO as interrupt\n");
 221                 goto fail_free_desc;
 222         }
 223
 224         irq = gpiod_to_irq(desc);
 225         if (irq < 0) {
 226                 dev_err(chip->parent, "Failed to translate GPIO to IRQ\n");
 227                 goto fail_unlock_irq;
 228         }
 229
 230         irqflags = IRQF_ONESHOT;
 231         if (agpio->triggering == ACPI_LEVEL_SENSITIVE) {
 232                 if (agpio->polarity == ACPI_ACTIVE_HIGH)
 233                         irqflags |= IRQF_TRIGGER_HIGH;
 234                 else
 235                         irqflags |= IRQF_TRIGGER_LOW;
 236         } else {
 237                 switch (agpio->polarity) {
 238                 case ACPI_ACTIVE_HIGH:
 239                         irqflags |= IRQF_TRIGGER_RISING;
 240                         break;
 241                 case ACPI_ACTIVE_LOW:
 242                         irqflags |= IRQF_TRIGGER_FALLING;
 243                         break;
 244                 default:
 245                         irqflags |= IRQF_TRIGGER_RISING |
 246                                     IRQF_TRIGGER_FALLING;
 247                         break;
 248                 }
 249         }
 250
 251         event = kzalloc(sizeof(*event), GFP_KERNEL);
 252         if (!event)
 253                 goto fail_unlock_irq;
 254
 255         event->handle = evt_handle;
 256         event->irq = irq;
 257         event->pin = pin;
 258         event->desc = desc;
 259
 260         ret = request_threaded_irq(event->irq, NULL, handler, irqflags,
 261                                    "ACPI:Event", event);
 262         if (ret) {
 263                 dev_err(chip->parent,
 264                         "Failed to setup interrupt handler for %d\n",
 265                         event->irq);
 266                 goto fail_free_event;
 267         }
 268
 269         list_add_tail(&event->node, &acpi_gpio->events);
 270         return AE_OK;
 271
 272 fail_free_event:
 273         kfree(event);
 274 fail_unlock_irq:
 275         gpiochip_unlock_as_irq(chip, pin);
 276 fail_free_desc:
 277         gpiochip_free_own_desc(desc);
 278
 279         return AE_ERROR;
 280 }
 281
 282 /**
 283  * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
 284  * @chip:      GPIO chip
 285  *
 286  * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
 287  * handled by ACPI event methods which need to be called from the GPIO
 288  * chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
 289  * gpio pins have acpi event methods and assigns interrupt handlers that calls
 290  * the acpi event methods for those pins.
 291  */
 292 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
 293 {
 294         struct acpi_gpio_chip *acpi_gpio;
 295         acpi_handle handle;
 296         acpi_status status;
 297
 298         if (!chip->parent || !chip->to_irq)
 299                 return;
 300
 301         handle = ACPI_HANDLE(chip->parent);
 302         if (!handle)
 303                 return;
 304
 305         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 306         if (ACPI_FAILURE(status))
 307                 return;
 308
 309         acpi_walk_resources(handle, "_AEI",
 310                             acpi_gpiochip_request_interrupt, acpi_gpio);
 311 }
 312 EXPORT_SYMBOL_GPL(acpi_gpiochip_request_interrupts);
 313
 314 /**
 315  * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
 316  * @chip:      GPIO chip
 317  *
 318  * Free interrupts associated with GPIO ACPI event method for the given
 319  * GPIO chip.
 320  */
 321 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
 322 {
 323         struct acpi_gpio_chip *acpi_gpio;
 324         struct acpi_gpio_event *event, *ep;
 325         acpi_handle handle;
 326         acpi_status status;
 327
 328         if (!chip->parent || !chip->to_irq)
 329                 return;
 330
 331         handle = ACPI_HANDLE(chip->parent);
 332         if (!handle)
 333                 return;
 334
 335         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 336         if (ACPI_FAILURE(status))
 337                 return;
 338
 339         list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
 340                 struct gpio_desc *desc;
 341
 342                 free_irq(event->irq, event);
 343                 desc = event->desc;
 344                 if (WARN_ON(IS_ERR(desc)))
 345                         continue;
 346                 gpiochip_unlock_as_irq(chip, event->pin);
 347                 gpiochip_free_own_desc(desc);
 348                 list_del(&event->node);
 349                 kfree(event);
 350         }
 351 }
 352 EXPORT_SYMBOL_GPL(acpi_gpiochip_free_interrupts);
 353
 354 int acpi_dev_add_driver_gpios(struct acpi_device *adev,
 355                               const struct acpi_gpio_mapping *gpios)
 356 {
 357         if (adev && gpios) {
 358                 adev->driver_gpios = gpios;
 359                 return 0;
 360         }
 361         return -EINVAL;
 362 }
 363 EXPORT_SYMBOL_GPL(acpi_dev_add_driver_gpios);
 364
 365 static bool acpi_get_driver_gpio_data(struct acpi_device *adev,
 366                                       const char *name, int index,
 367                                       struct acpi_reference_args *args)
 368 {
 369         const struct acpi_gpio_mapping *gm;
 370
 371         if (!adev->driver_gpios)
 372                 return false;
 373
 374         for (gm = adev->driver_gpios; gm->name; gm++)
 375                 if (!strcmp(name, gm->name) && gm->data && index < gm->size) {
 376                         const struct acpi_gpio_params *par = gm->data + index;
 377
 378                         args->adev = adev;
 379                         args->args[0] = par->crs_entry_index;
 380                         args->args[1] = par->line_index;
 381                         args->args[2] = par->active_low;
 382                         args->nargs = 3;
 383                         return true;
 384                 }
 385
 386         return false;
 387 }
 388
 389 struct acpi_gpio_lookup {
 390         struct acpi_gpio_info info;
 391         int index;
 392         int pin_index;
 393         bool active_low;
 394         struct acpi_device *adev;
 395         struct gpio_desc *desc;
 396         int n;
 397 };
 398
 399 static int acpi_populate_gpio_lookup(struct acpi_resource *ares, void *data)
 400 {
 401         struct acpi_gpio_lookup *lookup = data;
 402
 403         if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
 404                 return 1;
 405
 406         if (lookup->n++ == lookup->index && !lookup->desc) {
 407                 const struct acpi_resource_gpio *agpio = &ares->data.gpio;
 408                 int pin_index = lookup->pin_index;
 409
 410                 if (pin_index >= agpio->pin_table_length)
 411                         return 1;
 412
 413                 lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
 414                                               agpio->pin_table[pin_index]);
 415                 lookup->info.gpioint =
 416                         agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
 417
 418                 /*
 419                  * ActiveLow is only specified for GpioInt resource. If
 420                  * GpioIo is used then the only way to set the flag is
 421                  * to use _DSD "gpios" property.
 422                  * Note: we expect here:
 423                  * - ACPI_ACTIVE_LOW == GPIO_ACTIVE_LOW
 424                  * - ACPI_ACTIVE_HIGH == GPIO_ACTIVE_HIGH
 425                  */
 426                 if (lookup->info.gpioint) {
 427                         lookup->info.polarity = agpio->polarity;
 428                         lookup->info.triggering = agpio->triggering;
 429                 }
 430
 431         }
 432
 433         return 1;
 434 }
 435
 436 static int acpi_gpio_resource_lookup(struct acpi_gpio_lookup *lookup,
 437                                      struct acpi_gpio_info *info)
 438 {
 439         struct list_head res_list;
 440         int ret;
 441
 442         INIT_LIST_HEAD(&res_list);
 443
 444         ret = acpi_dev_get_resources(lookup->adev, &res_list,
 445                                      acpi_populate_gpio_lookup,
 446                                      lookup);
 447         if (ret < 0)
 448                 return ret;
 449
 450         acpi_dev_free_resource_list(&res_list);
 451
 452         if (!lookup->desc)
 453                 return -ENOENT;
 454
 455         if (info) {
 456                 *info = lookup->info;
 457                 if (lookup->active_low)
 458                         info->polarity = lookup->active_low;
 459         }
 460         return 0;
 461 }
 462
 463 static int acpi_gpio_property_lookup(struct fwnode_handle *fwnode,
 464                                      const char *propname, int index,
 465                                      struct acpi_gpio_lookup *lookup)
 466 {
 467         struct acpi_reference_args args;
 468         int ret;
 469
 470         memset(&args, 0, sizeof(args));
 471         ret = __acpi_node_get_property_reference(fwnode, propname, index, 3,
 472                                                  &args);
 473         if (ret) {
 474                 struct acpi_device *adev = to_acpi_device_node(fwnode);
 475
 476                 if (!adev)
 477                         return ret;
 478
 479                 if (!acpi_get_driver_gpio_data(adev, propname, index, &args))
 480                         return ret;
 481         }
 482         /*
 483          * The property was found and resolved, so need to lookup the GPIO based
 484          * on returned args.
 485          */
 486         lookup->adev = args.adev;
 487         if (args.nargs != 3)
 488                 return -EPROTO;
 489
 490         lookup->index = args.args[0];
 491         lookup->pin_index = args.args[1];
 492         lookup->active_low = !!args.args[2];
 493
 494         return 0;
 495 }
 496
 497 /**
 498  * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
 499  * @adev: pointer to a ACPI device to get GPIO from
 500  * @propname: Property name of the GPIO (optional)
 501  * @index: index of GpioIo/GpioInt resource (starting from %0)
 502  * @info: info pointer to fill in (optional)
 503  *
 504  * Function goes through ACPI resources for @adev and based on @index looks
 505  * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
 506  * and returns it. @index matches GpioIo/GpioInt resources only so if there
 507  * are total %3 GPIO resources, the index goes from %0 to %2.
 508  *
 509  * If @propname is specified the GPIO is looked using device property. In
 510  * that case @index is used to select the GPIO entry in the property value
 511  * (in case of multiple).
 512  *
 513  * If the GPIO cannot be translated or there is an error an ERR_PTR is
 514  * returned.
 515  *
 516  * Note: if the GPIO resource has multiple entries in the pin list, this
 517  * function only returns the first.
 518  */
 519 static struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
 520                                           const char *propname, int index,
 521                                           struct acpi_gpio_info *info)
 522 {
 523         struct acpi_gpio_lookup lookup;
 524         int ret;
 525
 526         if (!adev)
 527                 return ERR_PTR(-ENODEV);
 528
 529         memset(&lookup, 0, sizeof(lookup));
 530         lookup.index = index;
 531
 532         if (propname) {
 533                 dev_dbg(&adev->dev, "GPIO: looking up %s\n", propname);
 534
 535                 ret = acpi_gpio_property_lookup(acpi_fwnode_handle(adev),
 536                                                 propname, index, &lookup);
 537                 if (ret)
 538                         return ERR_PTR(ret);
 539
 540                 dev_dbg(&adev->dev, "GPIO: _DSD returned %s %d %d %u\n",
 541                         dev_name(&lookup.adev->dev), lookup.index,
 542                         lookup.pin_index, lookup.active_low);
 543         } else {
 544                 dev_dbg(&adev->dev, "GPIO: looking up %d in _CRS\n", index);
 545                 lookup.adev = adev;
 546         }
 547
 548         ret = acpi_gpio_resource_lookup(&lookup, info);
 549         return ret ? ERR_PTR(ret) : lookup.desc;
 550 }
 551
 552 struct gpio_desc *acpi_find_gpio(struct device *dev,
 553                                  const char *con_id,
 554                                  unsigned int idx,
 555                                  enum gpiod_flags flags,
 556                                  enum gpio_lookup_flags *lookupflags)
 557 {
 558         struct acpi_device *adev = ACPI_COMPANION(dev);
 559         struct acpi_gpio_info info;
 560         struct gpio_desc *desc;
 561         char propname[32];
 562         int i;
 563
 564         /* Try first from _DSD */
 565         for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
 566                 if (con_id && strcmp(con_id, "gpios")) {
 567                         snprintf(propname, sizeof(propname), "%s-%s",
 568                                  con_id, gpio_suffixes[i]);
 569                 } else {
 570                         snprintf(propname, sizeof(propname), "%s",
 571                                  gpio_suffixes[i]);
 572                 }
 573
 574                 desc = acpi_get_gpiod_by_index(adev, propname, idx, &info);
 575                 if (!IS_ERR(desc) || (PTR_ERR(desc) == -EPROBE_DEFER))
 576                         break;
 577         }
 578
 579         /* Then from plain _CRS GPIOs */
 580         if (IS_ERR(desc)) {
 581                 if (!acpi_can_fallback_to_crs(adev, con_id))
 582                         return ERR_PTR(-ENOENT);
 583
 584                 desc = acpi_get_gpiod_by_index(adev, NULL, idx, &info);
 585                 if (IS_ERR(desc))
 586                         return desc;
 587
 588                 if ((flags == GPIOD_OUT_LOW || flags == GPIOD_OUT_HIGH) &&
 589                     info.gpioint) {
 590                         dev_dbg(dev, "refusing GpioInt() entry when doing GPIOD_OUT_* lookup\n");
 591                         return ERR_PTR(-ENOENT);
 592                 }
 593         }
 594
 595         if (info.polarity == GPIO_ACTIVE_LOW)
 596                 *lookupflags |= GPIO_ACTIVE_LOW;
 597
 598         return desc;
 599 }
 600
 601 /**
 602  * acpi_node_get_gpiod() - get a GPIO descriptor from ACPI resources
 603  * @fwnode: pointer to an ACPI firmware node to get the GPIO information from
 604  * @propname: Property name of the GPIO
 605  * @index: index of GpioIo/GpioInt resource (starting from %0)
 606  * @info: info pointer to fill in (optional)
 607  *
 608  * If @fwnode is an ACPI device object, call %acpi_get_gpiod_by_index() for it.
 609  * Otherwise (ie. it is a data-only non-device object), use the property-based
 610  * GPIO lookup to get to the GPIO resource with the relevant information and use
 611  * that to obtain the GPIO descriptor to return.
 612  */
 613 struct gpio_desc *acpi_node_get_gpiod(struct fwnode_handle *fwnode,
 614                                       const char *propname, int index,
 615                                       struct acpi_gpio_info *info)
 616 {
 617         struct acpi_gpio_lookup lookup;
 618         struct acpi_device *adev;
 619         int ret;
 620
 621         adev = to_acpi_device_node(fwnode);
 622         if (adev)
 623                 return acpi_get_gpiod_by_index(adev, propname, index, info);
 624
 625         if (!is_acpi_data_node(fwnode))
 626                 return ERR_PTR(-ENODEV);
 627
 628         if (!propname)
 629                 return ERR_PTR(-EINVAL);
 630
 631         memset(&lookup, 0, sizeof(lookup));
 632         lookup.index = index;
 633
 634         ret = acpi_gpio_property_lookup(fwnode, propname, index, &lookup);
 635         if (ret)
 636                 return ERR_PTR(ret);
 637
 638         ret = acpi_gpio_resource_lookup(&lookup, info);
 639         return ret ? ERR_PTR(ret) : lookup.desc;
 640 }
 641
 642 /**
 643  * acpi_dev_gpio_irq_get() - Find GpioInt and translate it to Linux IRQ number
 644  * @adev: pointer to a ACPI device to get IRQ from
 645  * @index: index of GpioInt resource (starting from %0)
 646  *
 647  * If the device has one or more GpioInt resources, this function can be
 648  * used to translate from the GPIO offset in the resource to the Linux IRQ
 649  * number.
 650  *
 651  * Return: Linux IRQ number (>%0) on success, negative errno on failure.
 652  */
 653 int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
 654 {
 655         int idx, i;
 656         unsigned int irq_flags;
 657         int ret = -ENOENT;
 658
 659         for (i = 0, idx = 0; idx <= index; i++) {
 660                 struct acpi_gpio_info info;
 661                 struct gpio_desc *desc;
 662
 663                 desc = acpi_get_gpiod_by_index(adev, NULL, i, &info);
 664                 if (IS_ERR(desc)) {
 665                         ret = PTR_ERR(desc);
 666                         break;
 667                 }
 668                 if (info.gpioint && idx++ == index) {
 669                         int irq = gpiod_to_irq(desc);
 670
 671                         if (irq < 0)
 672                                 return irq;
 673
 674                         irq_flags = acpi_dev_get_irq_type(info.triggering,
 675                                                           info.polarity);
 676
 677                         /* Set type if specified and different than the current one */
 678                         if (irq_flags != IRQ_TYPE_NONE &&
 679                             irq_flags != irq_get_trigger_type(irq))
 680                                 irq_set_irq_type(irq, irq_flags);
 681
 682                         return irq;
 683                 }
 684
 685         }
 686         return ret;
 687 }
 688 EXPORT_SYMBOL_GPL(acpi_dev_gpio_irq_get);
 689
 690 static acpi_status
 691 acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
 692                             u32 bits, u64 *value, void *handler_context,
 693                             void *region_context)
 694 {
 695         struct acpi_gpio_chip *achip = region_context;
 696         struct gpio_chip *chip = achip->chip;
 697         struct acpi_resource_gpio *agpio;
 698         struct acpi_resource *ares;
 699         int pin_index = (int)address;
 700         acpi_status status;
 701         bool pull_up;
 702         int length;
 703         int i;
 704
 705         status = acpi_buffer_to_resource(achip->conn_info.connection,
 706                                          achip->conn_info.length, &ares);
 707         if (ACPI_FAILURE(status))
 708                 return status;
 709
 710         if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) {
 711                 ACPI_FREE(ares);
 712                 return AE_BAD_PARAMETER;
 713         }
 714
 715         agpio = &ares->data.gpio;
 716         pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP;
 717
 718         if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT &&
 719             function == ACPI_WRITE)) {
 720                 ACPI_FREE(ares);
 721                 return AE_BAD_PARAMETER;
 722         }
 723
 724         length = min(agpio->pin_table_length, (u16)(pin_index + bits));
 725         for (i = pin_index; i < length; ++i) {
 726                 int pin = agpio->pin_table[i];
 727                 struct acpi_gpio_connection *conn;
 728                 struct gpio_desc *desc;
 729                 bool found;
 730
 731                 pin = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, pin);
 732                 if (pin < 0) {
 733                         status = AE_BAD_PARAMETER;
 734                         goto out;
 735                 }
 736
 737                 mutex_lock(&achip->conn_lock);
 738
 739                 found = false;
 740                 list_for_each_entry(conn, &achip->conns, node) {
 741                         if (conn->pin == pin) {
 742                                 found = true;
 743                                 desc = conn->desc;
 744                                 break;
 745                         }
 746                 }
 747
 748                 /*
 749                  * The same GPIO can be shared between operation region and
 750                  * event but only if the access here is ACPI_READ. In that
 751                  * case we "borrow" the event GPIO instead.
 752                  */
 753                 if (!found && agpio->sharable == ACPI_SHARED &&
 754                      function == ACPI_READ) {
 755                         struct acpi_gpio_event *event;
 756
 757                         list_for_each_entry(event, &achip->events, node) {
 758                                 if (event->pin == pin) {
 759                                         desc = event->desc;
 760                                         found = true;
 761                                         break;
 762                                 }
 763                         }
 764                 }
 765
 766                 if (!found) {
 767                         desc = gpiochip_request_own_desc(chip, pin,
 768                                                          "ACPI:OpRegion");
 769                         if (IS_ERR(desc)) {
 770                                 status = AE_ERROR;
 771                                 mutex_unlock(&achip->conn_lock);
 772                                 goto out;
 773                         }
 774
 775                         switch (agpio->io_restriction) {
 776                         case ACPI_IO_RESTRICT_INPUT:
 777                                 gpiod_direction_input(desc);
 778                                 break;
 779                         case ACPI_IO_RESTRICT_OUTPUT:
 780                                 /*
 781                                  * ACPI GPIO resources don't contain an
 782                                  * initial value for the GPIO. Therefore we
 783                                  * deduce that value from the pull field
 784                                  * instead. If the pin is pulled up we
 785                                  * assume default to be high, otherwise
 786                                  * low.
 787                                  */
 788                                 gpiod_direction_output(desc, pull_up);
 789                                 break;
 790                         default:
 791                                 /*
 792                                  * Assume that the BIOS has configured the
 793                                  * direction and pull accordingly.
 794                                  */
 795                                 break;
 796                         }
 797
 798                         conn = kzalloc(sizeof(*conn), GFP_KERNEL);
 799                         if (!conn) {
 800                                 status = AE_NO_MEMORY;
 801                                 gpiochip_free_own_desc(desc);
 802                                 mutex_unlock(&achip->conn_lock);
 803                                 goto out;
 804                         }
 805
 806                         conn->pin = pin;
 807                         conn->desc = desc;
 808                         list_add_tail(&conn->node, &achip->conns);
 809                 }
 810
 811                 mutex_unlock(&achip->conn_lock);
 812
 813                 if (function == ACPI_WRITE)
 814                         gpiod_set_raw_value_cansleep(desc,
 815                                                      !!((1 << i) & *value));
 816                 else
 817                         *value |= (u64)gpiod_get_raw_value_cansleep(desc) << i;
 818         }
 819
 820 out:
 821         ACPI_FREE(ares);
 822         return status;
 823 }
 824
 825 static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip)
 826 {
 827         struct gpio_chip *chip = achip->chip;
 828         acpi_handle handle = ACPI_HANDLE(chip->parent);
 829         acpi_status status;
 830
 831         INIT_LIST_HEAD(&achip->conns);
 832         mutex_init(&achip->conn_lock);
 833         status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
 834                                                     acpi_gpio_adr_space_handler,
 835                                                     NULL, achip);
 836         if (ACPI_FAILURE(status))
 837                 dev_err(chip->parent,
 838                         "Failed to install GPIO OpRegion handler\n");
 839 }
 840
 841 static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
 842 {
 843         struct gpio_chip *chip = achip->chip;
 844         acpi_handle handle = ACPI_HANDLE(chip->parent);
 845         struct acpi_gpio_connection *conn, *tmp;
 846         acpi_status status;
 847
 848         status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
 849                                                    acpi_gpio_adr_space_handler);
 850         if (ACPI_FAILURE(status)) {
 851                 dev_err(chip->parent,
 852                         "Failed to remove GPIO OpRegion handler\n");
 853                 return;
 854         }
 855
 856         list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) {
 857                 gpiochip_free_own_desc(conn->desc);
 858                 list_del(&conn->node);
 859                 kfree(conn);
 860         }
 861 }
 862
 863 static struct gpio_desc *acpi_gpiochip_parse_own_gpio(
 864         struct acpi_gpio_chip *achip, struct fwnode_handle *fwnode,
 865         const char **name, unsigned int *lflags, unsigned int *dflags)
 866 {
 867         struct gpio_chip *chip = achip->chip;
 868         struct gpio_desc *desc;
 869         u32 gpios[2];
 870         int ret;
 871
 872         *lflags = 0;
 873         *dflags = 0;
 874         *name = NULL;
 875
 876         ret = fwnode_property_read_u32_array(fwnode, "gpios", gpios,
 877                                              ARRAY_SIZE(gpios));
 878         if (ret < 0)
 879                 return ERR_PTR(ret);
 880
 881         ret = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, gpios[0]);
 882         if (ret < 0)
 883                 return ERR_PTR(ret);
 884
 885         desc = gpiochip_get_desc(chip, ret);
 886         if (IS_ERR(desc))
 887                 return desc;
 888
 889         if (gpios[1])
 890                 *lflags |= GPIO_ACTIVE_LOW;
 891
 892         if (fwnode_property_present(fwnode, "input"))
 893                 *dflags |= GPIOD_IN;
 894         else if (fwnode_property_present(fwnode, "output-low"))
 895                 *dflags |= GPIOD_OUT_LOW;
 896         else if (fwnode_property_present(fwnode, "output-high"))
 897                 *dflags |= GPIOD_OUT_HIGH;
 898         else
 899                 return ERR_PTR(-EINVAL);
 900
 901         fwnode_property_read_string(fwnode, "line-name", name);
 902
 903         return desc;
 904 }
 905
 906 static void acpi_gpiochip_scan_gpios(struct acpi_gpio_chip *achip)
 907 {
 908         struct gpio_chip *chip = achip->chip;
 909         struct fwnode_handle *fwnode;
 910
 911         device_for_each_child_node(chip->parent, fwnode) {
 912                 unsigned int lflags, dflags;
 913                 struct gpio_desc *desc;
 914                 const char *name;
 915                 int ret;
 916
 917                 if (!fwnode_property_present(fwnode, "gpio-hog"))
 918                         continue;
 919
 920                 desc = acpi_gpiochip_parse_own_gpio(achip, fwnode, &name,
 921                                                     &lflags, &dflags);
 922                 if (IS_ERR(desc))
 923                         continue;
 924
 925                 ret = gpiod_hog(desc, name, lflags, dflags);
 926                 if (ret) {
 927                         dev_err(chip->parent, "Failed to hog GPIO\n");
 928                         fwnode_handle_put(fwnode);
 929                         return;
 930                 }
 931         }
 932 }
 933
 934 void acpi_gpiochip_add(struct gpio_chip *chip)
 935 {
 936         struct acpi_gpio_chip *acpi_gpio;
 937         acpi_handle handle;
 938         acpi_status status;
 939
 940         if (!chip || !chip->parent)
 941                 return;
 942
 943         handle = ACPI_HANDLE(chip->parent);
 944         if (!handle)
 945                 return;
 946
 947         acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
 948         if (!acpi_gpio) {
 949                 dev_err(chip->parent,
 950                         "Failed to allocate memory for ACPI GPIO chip\n");
 951                 return;
 952         }
 953
 954         acpi_gpio->chip = chip;
 955         INIT_LIST_HEAD(&acpi_gpio->events);
 956
 957         status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
 958         if (ACPI_FAILURE(status)) {
 959                 dev_err(chip->parent, "Failed to attach ACPI GPIO chip\n");
 960                 kfree(acpi_gpio);
 961                 return;
 962         }
 963
 964         if (!chip->names)
 965                 devprop_gpiochip_set_names(chip);
 966
 967         acpi_gpiochip_request_regions(acpi_gpio);
 968         acpi_gpiochip_scan_gpios(acpi_gpio);
 969         acpi_walk_dep_device_list(handle);
 970 }
 971
 972 void acpi_gpiochip_remove(struct gpio_chip *chip)
 973 {
 974         struct acpi_gpio_chip *acpi_gpio;
 975         acpi_handle handle;
 976         acpi_status status;
 977
 978         if (!chip || !chip->parent)
 979                 return;
 980
 981         handle = ACPI_HANDLE(chip->parent);
 982         if (!handle)
 983                 return;
 984
 985         status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
 986         if (ACPI_FAILURE(status)) {
 987                 dev_warn(chip->parent, "Failed to retrieve ACPI GPIO chip\n");
 988                 return;
 989         }
 990
 991         acpi_gpiochip_free_regions(acpi_gpio);
 992
 993         acpi_detach_data(handle, acpi_gpio_chip_dh);
 994         kfree(acpi_gpio);
 995 }
 996
 997 static int acpi_gpio_package_count(const union acpi_object *obj)
 998 {
 999         const union acpi_object *element = obj->package.elements;
1000         const union acpi_object *end = element + obj->package.count;
1001         unsigned int count = 0;
1002
1003         while (element < end) {
1004                 switch (element->type) {
1005                 case ACPI_TYPE_LOCAL_REFERENCE:
1006                         element += 3;
1007                         /* Fallthrough */
1008                 case ACPI_TYPE_INTEGER:
1009                         element++;
1010                         count++;
1011                         break;
1012
1013                 default:
1014                         return -EPROTO;
1015                 }
1016         }
1017
1018         return count;
1019 }
1020
1021 static int acpi_find_gpio_count(struct acpi_resource *ares, void *data)
1022 {
1023         unsigned int *count = data;
1024
1025         if (ares->type == ACPI_RESOURCE_TYPE_GPIO)
1026                 *count += ares->data.gpio.pin_table_length;
1027
1028         return 1;
1029 }
1030
1031 /**
1032  * acpi_gpio_count - return the number of GPIOs associated with a
1033  *              device / function or -ENOENT if no GPIO has been
1034  *              assigned to the requested function.
1035  * @dev:        GPIO consumer, can be NULL for system-global GPIOs
1036  * @con_id:     function within the GPIO consumer
1037  */
1038 int acpi_gpio_count(struct device *dev, const char *con_id)
1039 {
1040         struct acpi_device *adev = ACPI_COMPANION(dev);
1041         const union acpi_object *obj;
1042         const struct acpi_gpio_mapping *gm;
1043         int count = -ENOENT;
1044         int ret;
1045         char propname[32];
1046         unsigned int i;
1047
1048         /* Try first from _DSD */
1049         for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
1050                 if (con_id && strcmp(con_id, "gpios"))
1051                         snprintf(propname, sizeof(propname), "%s-%s",
1052                                  con_id, gpio_suffixes[i]);
1053                 else
1054                         snprintf(propname, sizeof(propname), "%s",
1055                                  gpio_suffixes[i]);
1056
1057                 ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY,
1058                                             &obj);
1059                 if (ret == 0) {
1060                         if (obj->type == ACPI_TYPE_LOCAL_REFERENCE)
1061                                 count = 1;
1062                         else if (obj->type == ACPI_TYPE_PACKAGE)
1063                                 count = acpi_gpio_package_count(obj);
1064                 } else if (adev->driver_gpios) {
1065                         for (gm = adev->driver_gpios; gm->name; gm++)
1066                                 if (strcmp(propname, gm->name) == 0) {
1067                                         count = gm->size;
1068                                         break;
1069                                 }
1070                 }
1071                 if (count >= 0)
1072                         break;
1073         }
1074
1075         /* Then from plain _CRS GPIOs */
1076         if (count < 0) {
1077                 struct list_head resource_list;
1078                 unsigned int crs_count = 0;
1079
1080                 INIT_LIST_HEAD(&resource_list);
1081                 acpi_dev_get_resources(adev, &resource_list,
1082                                        acpi_find_gpio_count, &crs_count);
1083                 acpi_dev_free_resource_list(&resource_list);
1084                 if (crs_count > 0)
1085                         count = crs_count;
1086         }
1087         return count;
1088 }
1089
1090 struct acpi_crs_lookup {
1091         struct list_head node;
1092         struct acpi_device *adev;
1093         const char *con_id;
1094 };
1095
1096 static DEFINE_MUTEX(acpi_crs_lookup_lock);
1097 static LIST_HEAD(acpi_crs_lookup_list);
1098
1099 bool acpi_can_fallback_to_crs(struct acpi_device *adev, const char *con_id)
1100 {
1101         struct acpi_crs_lookup *l, *lookup = NULL;
1102
1103         /* Never allow fallback if the device has properties */
1104         if (adev->data.properties || adev->driver_gpios)
1105                 return false;
1106
1107         mutex_lock(&acpi_crs_lookup_lock);
1108
1109         list_for_each_entry(l, &acpi_crs_lookup_list, node) {
1110                 if (l->adev == adev) {
1111                         lookup = l;
1112                         break;
1113                 }
1114         }
1115
1116         if (!lookup) {
1117                 lookup = kmalloc(sizeof(*lookup), GFP_KERNEL);
1118                 if (lookup) {
1119                         lookup->adev = adev;
1120                         lookup->con_id = kstrdup(con_id, GFP_KERNEL);
1121                         list_add_tail(&lookup->node, &acpi_crs_lookup_list);
1122                 }
1123         }
1124
1125         mutex_unlock(&acpi_crs_lookup_lock);
1126
1127         return lookup &&
1128                 ((!lookup->con_id && !con_id) ||
1129                  (lookup->con_id && con_id &&
1130                   strcmp(lookup->con_id, con_id) == 0));
1131 }