2 * ACPI helpers for GPIO API
4 * Copyright (C) 2012, Intel Corporation
5 * Authors: Mathias Nyman <mathias.nyman@linux.intel.com>
6 * Mika Westerberg <mika.westerberg@linux.intel.com>
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.
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>
25 struct acpi_gpio_event {
26 struct list_head node;
30 struct gpio_desc *desc;
33 struct acpi_gpio_connection {
34 struct list_head node;
36 struct gpio_desc *desc;
39 struct acpi_gpio_chip {
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.
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;
52 static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
57 return ACPI_HANDLE(gc->dev) == data;
62 * acpi_gpiochip_pin_to_gpio_offset() - translates ACPI GPIO to Linux GPIO
64 * @pin: ACPI GPIO pin number from GpioIo/GpioInt resource
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.
70 * Typically the returned offset is same as @pin, but if the GPIO
71 * controller uses pin controller and the mapping is not contigous the
72 * offset might be different.
74 static int acpi_gpiochip_pin_to_gpio_offset(struct gpio_chip *chip, int pin)
76 struct gpio_pin_range *pin_range;
78 /* If there are no ranges in this chip, use 1:1 mapping */
79 if (list_empty(&chip->pin_ranges))
82 list_for_each_entry(pin_range, &chip->pin_ranges, node) {
83 const struct pinctrl_gpio_range *range = &pin_range->range;
87 for (i = 0; i < range->npins; i++) {
88 if (range->pins[i] == pin)
89 return range->base + i - chip->base;
92 if (pin >= range->pin_base &&
93 pin < range->pin_base + range->npins) {
96 gpio_base = range->base - chip->base;
97 return gpio_base + pin - range->pin_base;
105 static inline int acpi_gpiochip_pin_to_gpio_offset(struct gpio_chip *chip,
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)
117 * Returns GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR
121 static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
123 struct gpio_chip *chip;
128 status = acpi_get_handle(NULL, path, &handle);
129 if (ACPI_FAILURE(status))
130 return ERR_PTR(-ENODEV);
132 chip = gpiochip_find(handle, acpi_gpiochip_find);
134 return ERR_PTR(-ENODEV);
136 offset = acpi_gpiochip_pin_to_gpio_offset(chip, pin);
138 return ERR_PTR(offset);
140 return gpiochip_get_desc(chip, offset);
143 static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
145 struct acpi_gpio_event *event = data;
147 acpi_evaluate_object(event->handle, NULL, NULL, NULL);
152 static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
154 struct acpi_gpio_event *event = data;
156 acpi_execute_simple_method(event->handle, NULL, event->pin);
161 static void acpi_gpio_chip_dh(acpi_handle handle, void *data)
163 /* The address of this function is used as a key. */
166 static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
169 struct acpi_gpio_chip *acpi_gpio = context;
170 struct gpio_chip *chip = acpi_gpio->chip;
171 struct acpi_resource_gpio *agpio;
172 acpi_handle handle, evt_handle;
173 struct acpi_gpio_event *event;
174 irq_handler_t handler = NULL;
175 struct gpio_desc *desc;
176 unsigned long irqflags;
179 if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
182 agpio = &ares->data.gpio;
183 if (agpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT)
186 handle = ACPI_HANDLE(chip->dev);
187 pin = agpio->pin_table[0];
191 sprintf(ev_name, "_%c%02X",
192 agpio->triggering == ACPI_EDGE_SENSITIVE ? 'E' : 'L',
194 if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
195 handler = acpi_gpio_irq_handler;
198 if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
199 handler = acpi_gpio_irq_handler_evt;
202 return AE_BAD_PARAMETER;
204 pin = acpi_gpiochip_pin_to_gpio_offset(chip, pin);
206 return AE_BAD_PARAMETER;
208 desc = gpiochip_request_own_desc(chip, pin, "ACPI:Event");
210 dev_err(chip->dev, "Failed to request GPIO\n");
214 gpiod_direction_input(desc);
216 ret = gpiochip_lock_as_irq(chip, pin);
218 dev_err(chip->dev, "Failed to lock GPIO as interrupt\n");
222 irq = gpiod_to_irq(desc);
224 dev_err(chip->dev, "Failed to translate GPIO to IRQ\n");
225 goto fail_unlock_irq;
228 irqflags = IRQF_ONESHOT;
229 if (agpio->triggering == ACPI_LEVEL_SENSITIVE) {
230 if (agpio->polarity == ACPI_ACTIVE_HIGH)
231 irqflags |= IRQF_TRIGGER_HIGH;
233 irqflags |= IRQF_TRIGGER_LOW;
235 switch (agpio->polarity) {
236 case ACPI_ACTIVE_HIGH:
237 irqflags |= IRQF_TRIGGER_RISING;
239 case ACPI_ACTIVE_LOW:
240 irqflags |= IRQF_TRIGGER_FALLING;
243 irqflags |= IRQF_TRIGGER_RISING |
244 IRQF_TRIGGER_FALLING;
249 event = kzalloc(sizeof(*event), GFP_KERNEL);
251 goto fail_unlock_irq;
253 event->handle = evt_handle;
258 ret = request_threaded_irq(event->irq, NULL, handler, irqflags,
259 "ACPI:Event", event);
261 dev_err(chip->dev, "Failed to setup interrupt handler for %d\n",
263 goto fail_free_event;
266 list_add_tail(&event->node, &acpi_gpio->events);
272 gpiochip_unlock_as_irq(chip, pin);
274 gpiochip_free_own_desc(desc);
280 * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
283 * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
284 * handled by ACPI event methods which need to be called from the GPIO
285 * chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
286 * gpio pins have acpi event methods and assigns interrupt handlers that calls
287 * the acpi event methods for those pins.
289 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
291 struct acpi_gpio_chip *acpi_gpio;
295 if (!chip->dev || !chip->to_irq)
298 handle = ACPI_HANDLE(chip->dev);
302 status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
303 if (ACPI_FAILURE(status))
306 INIT_LIST_HEAD(&acpi_gpio->events);
307 acpi_walk_resources(handle, "_AEI",
308 acpi_gpiochip_request_interrupt, acpi_gpio);
312 * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
315 * Free interrupts associated with GPIO ACPI event method for the given
318 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
320 struct acpi_gpio_chip *acpi_gpio;
321 struct acpi_gpio_event *event, *ep;
325 if (!chip->dev || !chip->to_irq)
328 handle = ACPI_HANDLE(chip->dev);
332 status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
333 if (ACPI_FAILURE(status))
336 list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
337 struct gpio_desc *desc;
339 free_irq(event->irq, event);
341 if (WARN_ON(IS_ERR(desc)))
343 gpiochip_unlock_as_irq(chip, event->pin);
344 gpiochip_free_own_desc(desc);
345 list_del(&event->node);
350 int acpi_dev_add_driver_gpios(struct acpi_device *adev,
351 const struct acpi_gpio_mapping *gpios)
354 adev->driver_gpios = gpios;
359 EXPORT_SYMBOL_GPL(acpi_dev_add_driver_gpios);
361 static bool acpi_get_driver_gpio_data(struct acpi_device *adev,
362 const char *name, int index,
363 struct acpi_reference_args *args)
365 const struct acpi_gpio_mapping *gm;
367 if (!adev->driver_gpios)
370 for (gm = adev->driver_gpios; gm->name; gm++)
371 if (!strcmp(name, gm->name) && gm->data && index < gm->size) {
372 const struct acpi_gpio_params *par = gm->data + index;
375 args->args[0] = par->crs_entry_index;
376 args->args[1] = par->line_index;
377 args->args[2] = par->active_low;
385 struct acpi_gpio_lookup {
386 struct acpi_gpio_info info;
389 struct gpio_desc *desc;
393 static int acpi_find_gpio(struct acpi_resource *ares, void *data)
395 struct acpi_gpio_lookup *lookup = data;
397 if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
400 if (lookup->n++ == lookup->index && !lookup->desc) {
401 const struct acpi_resource_gpio *agpio = &ares->data.gpio;
402 int pin_index = lookup->pin_index;
404 if (pin_index >= agpio->pin_table_length)
407 lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
408 agpio->pin_table[pin_index]);
409 lookup->info.gpioint =
410 agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
413 * ActiveLow is only specified for GpioInt resource. If
414 * GpioIo is used then the only way to set the flag is
415 * to use _DSD "gpios" property.
417 if (lookup->info.gpioint)
418 lookup->info.active_low =
419 agpio->polarity == ACPI_ACTIVE_LOW;
426 * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
427 * @adev: pointer to a ACPI device to get GPIO from
428 * @propname: Property name of the GPIO (optional)
429 * @index: index of GpioIo/GpioInt resource (starting from %0)
430 * @info: info pointer to fill in (optional)
432 * Function goes through ACPI resources for @adev and based on @index looks
433 * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
434 * and returns it. @index matches GpioIo/GpioInt resources only so if there
435 * are total %3 GPIO resources, the index goes from %0 to %2.
437 * If @propname is specified the GPIO is looked using device property. In
438 * that case @index is used to select the GPIO entry in the property value
439 * (in case of multiple).
441 * If the GPIO cannot be translated or there is an error an ERR_PTR is
444 * Note: if the GPIO resource has multiple entries in the pin list, this
445 * function only returns the first.
447 struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
448 const char *propname, int index,
449 struct acpi_gpio_info *info)
451 struct acpi_gpio_lookup lookup;
452 struct list_head resource_list;
453 bool active_low = false;
457 return ERR_PTR(-ENODEV);
459 memset(&lookup, 0, sizeof(lookup));
460 lookup.index = index;
463 struct acpi_reference_args args;
465 dev_dbg(&adev->dev, "GPIO: looking up %s\n", propname);
467 memset(&args, 0, sizeof(args));
468 ret = acpi_dev_get_property_reference(adev, propname,
471 bool found = acpi_get_driver_gpio_data(adev, propname,
478 * The property was found and resolved so need to
479 * lookup the GPIO based on returned args instead.
482 if (args.nargs >= 2) {
483 lookup.index = args.args[0];
484 lookup.pin_index = args.args[1];
486 * 3rd argument, if present is used to
487 * specify active_low.
490 active_low = !!args.args[2];
493 dev_dbg(&adev->dev, "GPIO: _DSD returned %s %zd %llu %llu %llu\n",
494 dev_name(&adev->dev), args.nargs,
495 args.args[0], args.args[1], args.args[2]);
497 dev_dbg(&adev->dev, "GPIO: looking up %d in _CRS\n", index);
500 INIT_LIST_HEAD(&resource_list);
501 ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio,
506 acpi_dev_free_resource_list(&resource_list);
508 if (lookup.desc && info) {
511 info->active_low = active_low;
514 return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT);
518 acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
519 u32 bits, u64 *value, void *handler_context,
520 void *region_context)
522 struct acpi_gpio_chip *achip = region_context;
523 struct gpio_chip *chip = achip->chip;
524 struct acpi_resource_gpio *agpio;
525 struct acpi_resource *ares;
526 int pin_index = (int)address;
532 status = acpi_buffer_to_resource(achip->conn_info.connection,
533 achip->conn_info.length, &ares);
534 if (ACPI_FAILURE(status))
537 if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) {
539 return AE_BAD_PARAMETER;
542 agpio = &ares->data.gpio;
543 pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP;
545 if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT &&
546 function == ACPI_WRITE)) {
548 return AE_BAD_PARAMETER;
551 length = min(agpio->pin_table_length, (u16)(pin_index + bits));
552 for (i = pin_index; i < length; ++i) {
553 int pin = agpio->pin_table[i];
554 struct acpi_gpio_connection *conn;
555 struct gpio_desc *desc;
558 pin = acpi_gpiochip_pin_to_gpio_offset(chip, pin);
560 status = AE_BAD_PARAMETER;
564 mutex_lock(&achip->conn_lock);
567 list_for_each_entry(conn, &achip->conns, node) {
568 if (conn->pin == pin) {
575 desc = gpiochip_request_own_desc(chip, pin,
579 mutex_unlock(&achip->conn_lock);
583 switch (agpio->io_restriction) {
584 case ACPI_IO_RESTRICT_INPUT:
585 gpiod_direction_input(desc);
587 case ACPI_IO_RESTRICT_OUTPUT:
589 * ACPI GPIO resources don't contain an
590 * initial value for the GPIO. Therefore we
591 * deduce that value from the pull field
592 * instead. If the pin is pulled up we
593 * assume default to be high, otherwise
596 gpiod_direction_output(desc, pull_up);
600 * Assume that the BIOS has configured the
601 * direction and pull accordingly.
606 conn = kzalloc(sizeof(*conn), GFP_KERNEL);
608 status = AE_NO_MEMORY;
609 gpiochip_free_own_desc(desc);
610 mutex_unlock(&achip->conn_lock);
616 list_add_tail(&conn->node, &achip->conns);
619 mutex_unlock(&achip->conn_lock);
621 if (function == ACPI_WRITE)
622 gpiod_set_raw_value_cansleep(desc,
623 !!((1 << i) & *value));
625 *value |= (u64)gpiod_get_raw_value_cansleep(desc) << i;
633 static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip)
635 struct gpio_chip *chip = achip->chip;
636 acpi_handle handle = ACPI_HANDLE(chip->dev);
639 INIT_LIST_HEAD(&achip->conns);
640 mutex_init(&achip->conn_lock);
641 status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
642 acpi_gpio_adr_space_handler,
644 if (ACPI_FAILURE(status))
645 dev_err(chip->dev, "Failed to install GPIO OpRegion handler\n");
648 static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
650 struct gpio_chip *chip = achip->chip;
651 acpi_handle handle = ACPI_HANDLE(chip->dev);
652 struct acpi_gpio_connection *conn, *tmp;
655 status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
656 acpi_gpio_adr_space_handler);
657 if (ACPI_FAILURE(status)) {
658 dev_err(chip->dev, "Failed to remove GPIO OpRegion handler\n");
662 list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) {
663 gpiochip_free_own_desc(conn->desc);
664 list_del(&conn->node);
669 void acpi_gpiochip_add(struct gpio_chip *chip)
671 struct acpi_gpio_chip *acpi_gpio;
675 if (!chip || !chip->dev)
678 handle = ACPI_HANDLE(chip->dev);
682 acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
685 "Failed to allocate memory for ACPI GPIO chip\n");
689 acpi_gpio->chip = chip;
691 status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
692 if (ACPI_FAILURE(status)) {
693 dev_err(chip->dev, "Failed to attach ACPI GPIO chip\n");
698 acpi_gpiochip_request_regions(acpi_gpio);
701 void acpi_gpiochip_remove(struct gpio_chip *chip)
703 struct acpi_gpio_chip *acpi_gpio;
707 if (!chip || !chip->dev)
710 handle = ACPI_HANDLE(chip->dev);
714 status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
715 if (ACPI_FAILURE(status)) {
716 dev_warn(chip->dev, "Failed to retrieve ACPI GPIO chip\n");
720 acpi_gpiochip_free_regions(acpi_gpio);
722 acpi_detach_data(handle, acpi_gpio_chip_dh);
726 static unsigned int acpi_gpio_package_count(const union acpi_object *obj)
728 const union acpi_object *element = obj->package.elements;
729 const union acpi_object *end = element + obj->package.count;
730 unsigned int count = 0;
732 while (element < end) {
733 if (element->type == ACPI_TYPE_LOCAL_REFERENCE)
741 static int acpi_find_gpio_count(struct acpi_resource *ares, void *data)
743 unsigned int *count = data;
745 if (ares->type == ACPI_RESOURCE_TYPE_GPIO)
746 *count += ares->data.gpio.pin_table_length;
752 * acpi_gpio_count - return the number of GPIOs associated with a
753 * device / function or -ENOENT if no GPIO has been
754 * assigned to the requested function.
755 * @dev: GPIO consumer, can be NULL for system-global GPIOs
756 * @con_id: function within the GPIO consumer
758 int acpi_gpio_count(struct device *dev, const char *con_id)
760 struct acpi_device *adev = ACPI_COMPANION(dev);
761 const union acpi_object *obj;
762 const struct acpi_gpio_mapping *gm;
768 /* Try first from _DSD */
769 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
770 if (con_id && strcmp(con_id, "gpios"))
771 snprintf(propname, sizeof(propname), "%s-%s",
772 con_id, gpio_suffixes[i]);
774 snprintf(propname, sizeof(propname), "%s",
777 ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY,
780 if (obj->type == ACPI_TYPE_LOCAL_REFERENCE)
782 else if (obj->type == ACPI_TYPE_PACKAGE)
783 count = acpi_gpio_package_count(obj);
784 } else if (adev->driver_gpios) {
785 for (gm = adev->driver_gpios; gm->name; gm++)
786 if (strcmp(propname, gm->name) == 0) {
795 /* Then from plain _CRS GPIOs */
797 struct list_head resource_list;
798 unsigned int crs_count = 0;
800 INIT_LIST_HEAD(&resource_list);
801 acpi_dev_get_resources(adev, &resource_list,
802 acpi_find_gpio_count, &crs_count);
803 acpi_dev_free_resource_list(&resource_list);