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 contiguous 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 * 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.
122 static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
124 struct gpio_chip *chip;
129 status = acpi_get_handle(NULL, path, &handle);
130 if (ACPI_FAILURE(status))
131 return ERR_PTR(-ENODEV);
133 chip = gpiochip_find(handle, acpi_gpiochip_find);
135 return ERR_PTR(-EPROBE_DEFER);
137 offset = acpi_gpiochip_pin_to_gpio_offset(chip, pin);
139 return ERR_PTR(offset);
141 return gpiochip_get_desc(chip, offset);
144 static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
146 struct acpi_gpio_event *event = data;
148 acpi_evaluate_object(event->handle, NULL, NULL, NULL);
153 static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
155 struct acpi_gpio_event *event = data;
157 acpi_execute_simple_method(event->handle, NULL, event->pin);
162 static void acpi_gpio_chip_dh(acpi_handle handle, void *data)
164 /* The address of this function is used as a key. */
167 static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
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;
180 if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
183 agpio = &ares->data.gpio;
184 if (agpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT)
187 handle = ACPI_HANDLE(chip->dev);
188 pin = agpio->pin_table[0];
192 sprintf(ev_name, "_%c%02X",
193 agpio->triggering == ACPI_EDGE_SENSITIVE ? 'E' : 'L',
195 if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
196 handler = acpi_gpio_irq_handler;
199 if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
200 handler = acpi_gpio_irq_handler_evt;
203 return AE_BAD_PARAMETER;
205 pin = acpi_gpiochip_pin_to_gpio_offset(chip, pin);
207 return AE_BAD_PARAMETER;
209 desc = gpiochip_request_own_desc(chip, pin, "ACPI:Event");
211 dev_err(chip->dev, "Failed to request GPIO\n");
215 gpiod_direction_input(desc);
217 ret = gpiochip_lock_as_irq(chip, pin);
219 dev_err(chip->dev, "Failed to lock GPIO as interrupt\n");
223 irq = gpiod_to_irq(desc);
225 dev_err(chip->dev, "Failed to translate GPIO to IRQ\n");
226 goto fail_unlock_irq;
229 irqflags = IRQF_ONESHOT;
230 if (agpio->triggering == ACPI_LEVEL_SENSITIVE) {
231 if (agpio->polarity == ACPI_ACTIVE_HIGH)
232 irqflags |= IRQF_TRIGGER_HIGH;
234 irqflags |= IRQF_TRIGGER_LOW;
236 switch (agpio->polarity) {
237 case ACPI_ACTIVE_HIGH:
238 irqflags |= IRQF_TRIGGER_RISING;
240 case ACPI_ACTIVE_LOW:
241 irqflags |= IRQF_TRIGGER_FALLING;
244 irqflags |= IRQF_TRIGGER_RISING |
245 IRQF_TRIGGER_FALLING;
250 event = kzalloc(sizeof(*event), GFP_KERNEL);
252 goto fail_unlock_irq;
254 event->handle = evt_handle;
259 ret = request_threaded_irq(event->irq, NULL, handler, irqflags,
260 "ACPI:Event", event);
262 dev_err(chip->dev, "Failed to setup interrupt handler for %d\n",
264 goto fail_free_event;
267 list_add_tail(&event->node, &acpi_gpio->events);
273 gpiochip_unlock_as_irq(chip, pin);
275 gpiochip_free_own_desc(desc);
281 * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
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.
290 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
292 struct acpi_gpio_chip *acpi_gpio;
296 if (!chip->dev || !chip->to_irq)
299 handle = ACPI_HANDLE(chip->dev);
303 status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
304 if (ACPI_FAILURE(status))
307 INIT_LIST_HEAD(&acpi_gpio->events);
308 acpi_walk_resources(handle, "_AEI",
309 acpi_gpiochip_request_interrupt, acpi_gpio);
311 EXPORT_SYMBOL_GPL(acpi_gpiochip_request_interrupts);
314 * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
317 * Free interrupts associated with GPIO ACPI event method for the given
320 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
322 struct acpi_gpio_chip *acpi_gpio;
323 struct acpi_gpio_event *event, *ep;
327 if (!chip->dev || !chip->to_irq)
330 handle = ACPI_HANDLE(chip->dev);
334 status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
335 if (ACPI_FAILURE(status))
338 list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
339 struct gpio_desc *desc;
341 free_irq(event->irq, event);
343 if (WARN_ON(IS_ERR(desc)))
345 gpiochip_unlock_as_irq(chip, event->pin);
346 gpiochip_free_own_desc(desc);
347 list_del(&event->node);
351 EXPORT_SYMBOL_GPL(acpi_gpiochip_free_interrupts);
353 int acpi_dev_add_driver_gpios(struct acpi_device *adev,
354 const struct acpi_gpio_mapping *gpios)
357 adev->driver_gpios = gpios;
362 EXPORT_SYMBOL_GPL(acpi_dev_add_driver_gpios);
364 static bool acpi_get_driver_gpio_data(struct acpi_device *adev,
365 const char *name, int index,
366 struct acpi_reference_args *args)
368 const struct acpi_gpio_mapping *gm;
370 if (!adev->driver_gpios)
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;
378 args->args[0] = par->crs_entry_index;
379 args->args[1] = par->line_index;
380 args->args[2] = par->active_low;
388 struct acpi_gpio_lookup {
389 struct acpi_gpio_info info;
393 struct acpi_device *adev;
394 struct gpio_desc *desc;
398 static int acpi_find_gpio(struct acpi_resource *ares, void *data)
400 struct acpi_gpio_lookup *lookup = data;
402 if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
405 if (lookup->n++ == lookup->index && !lookup->desc) {
406 const struct acpi_resource_gpio *agpio = &ares->data.gpio;
407 int pin_index = lookup->pin_index;
409 if (pin_index >= agpio->pin_table_length)
412 lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
413 agpio->pin_table[pin_index]);
414 lookup->info.gpioint =
415 agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
418 * ActiveLow is only specified for GpioInt resource. If
419 * GpioIo is used then the only way to set the flag is
420 * to use _DSD "gpios" property.
422 if (lookup->info.gpioint)
423 lookup->info.active_low =
424 agpio->polarity == ACPI_ACTIVE_LOW;
430 static int acpi_gpio_resource_lookup(struct acpi_gpio_lookup *lookup,
431 struct acpi_gpio_info *info)
433 struct list_head res_list;
436 INIT_LIST_HEAD(&res_list);
438 ret = acpi_dev_get_resources(lookup->adev, &res_list, acpi_find_gpio,
443 acpi_dev_free_resource_list(&res_list);
449 *info = lookup->info;
450 if (lookup->active_low)
451 info->active_low = lookup->active_low;
456 static int acpi_gpio_property_lookup(struct acpi_device *adev,
457 const char *propname, int index,
458 struct acpi_gpio_lookup *lookup)
460 struct acpi_reference_args args;
463 memset(&args, 0, sizeof(args));
464 ret = acpi_dev_get_property_reference(adev, propname, index, &args);
465 if (ret && !acpi_get_driver_gpio_data(adev, propname, index, &args))
469 * The property was found and resolved, so need to lookup the GPIO based
472 lookup->adev = args.adev;
473 if (args.nargs >= 2) {
474 lookup->index = args.args[0];
475 lookup->pin_index = args.args[1];
476 /* 3rd argument, if present is used to specify active_low. */
478 lookup->active_low = !!args.args[2];
484 * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
485 * @adev: pointer to a ACPI device to get GPIO from
486 * @propname: Property name of the GPIO (optional)
487 * @index: index of GpioIo/GpioInt resource (starting from %0)
488 * @info: info pointer to fill in (optional)
490 * Function goes through ACPI resources for @adev and based on @index looks
491 * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
492 * and returns it. @index matches GpioIo/GpioInt resources only so if there
493 * are total %3 GPIO resources, the index goes from %0 to %2.
495 * If @propname is specified the GPIO is looked using device property. In
496 * that case @index is used to select the GPIO entry in the property value
497 * (in case of multiple).
499 * If the GPIO cannot be translated or there is an error an ERR_PTR is
502 * Note: if the GPIO resource has multiple entries in the pin list, this
503 * function only returns the first.
505 struct gpio_desc *acpi_get_gpiod_by_index(struct acpi_device *adev,
506 const char *propname, int index,
507 struct acpi_gpio_info *info)
509 struct acpi_gpio_lookup lookup;
513 return ERR_PTR(-ENODEV);
515 memset(&lookup, 0, sizeof(lookup));
516 lookup.index = index;
519 dev_dbg(&adev->dev, "GPIO: looking up %s\n", propname);
521 ret = acpi_gpio_property_lookup(adev, propname, index, &lookup);
525 dev_dbg(&adev->dev, "GPIO: _DSD returned %s %d %d %u\n",
526 dev_name(&lookup.adev->dev), lookup.index,
527 lookup.pin_index, lookup.active_low);
529 dev_dbg(&adev->dev, "GPIO: looking up %d in _CRS\n", index);
533 ret = acpi_gpio_resource_lookup(&lookup, info);
534 return ret ? ERR_PTR(ret) : lookup.desc;
538 * acpi_dev_gpio_irq_get() - Find GpioInt and translate it to Linux IRQ number
539 * @adev: pointer to a ACPI device to get IRQ from
540 * @index: index of GpioInt resource (starting from %0)
542 * If the device has one or more GpioInt resources, this function can be
543 * used to translate from the GPIO offset in the resource to the Linux IRQ
546 * Return: Linux IRQ number (>%0) on success, negative errno on failure.
548 int acpi_dev_gpio_irq_get(struct acpi_device *adev, int index)
552 for (i = 0, idx = 0; idx <= index; i++) {
553 struct acpi_gpio_info info;
554 struct gpio_desc *desc;
556 desc = acpi_get_gpiod_by_index(adev, NULL, i, &info);
559 if (info.gpioint && idx++ == index)
560 return gpiod_to_irq(desc);
564 EXPORT_SYMBOL_GPL(acpi_dev_gpio_irq_get);
567 acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
568 u32 bits, u64 *value, void *handler_context,
569 void *region_context)
571 struct acpi_gpio_chip *achip = region_context;
572 struct gpio_chip *chip = achip->chip;
573 struct acpi_resource_gpio *agpio;
574 struct acpi_resource *ares;
575 int pin_index = (int)address;
581 status = acpi_buffer_to_resource(achip->conn_info.connection,
582 achip->conn_info.length, &ares);
583 if (ACPI_FAILURE(status))
586 if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) {
588 return AE_BAD_PARAMETER;
591 agpio = &ares->data.gpio;
592 pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP;
594 if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT &&
595 function == ACPI_WRITE)) {
597 return AE_BAD_PARAMETER;
600 length = min(agpio->pin_table_length, (u16)(pin_index + bits));
601 for (i = pin_index; i < length; ++i) {
602 int pin = agpio->pin_table[i];
603 struct acpi_gpio_connection *conn;
604 struct gpio_desc *desc;
607 pin = acpi_gpiochip_pin_to_gpio_offset(chip, pin);
609 status = AE_BAD_PARAMETER;
613 mutex_lock(&achip->conn_lock);
616 list_for_each_entry(conn, &achip->conns, node) {
617 if (conn->pin == pin) {
624 desc = gpiochip_request_own_desc(chip, pin,
628 mutex_unlock(&achip->conn_lock);
632 switch (agpio->io_restriction) {
633 case ACPI_IO_RESTRICT_INPUT:
634 gpiod_direction_input(desc);
636 case ACPI_IO_RESTRICT_OUTPUT:
638 * ACPI GPIO resources don't contain an
639 * initial value for the GPIO. Therefore we
640 * deduce that value from the pull field
641 * instead. If the pin is pulled up we
642 * assume default to be high, otherwise
645 gpiod_direction_output(desc, pull_up);
649 * Assume that the BIOS has configured the
650 * direction and pull accordingly.
655 conn = kzalloc(sizeof(*conn), GFP_KERNEL);
657 status = AE_NO_MEMORY;
658 gpiochip_free_own_desc(desc);
659 mutex_unlock(&achip->conn_lock);
665 list_add_tail(&conn->node, &achip->conns);
668 mutex_unlock(&achip->conn_lock);
670 if (function == ACPI_WRITE)
671 gpiod_set_raw_value_cansleep(desc,
672 !!((1 << i) & *value));
674 *value |= (u64)gpiod_get_raw_value_cansleep(desc) << i;
682 static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip)
684 struct gpio_chip *chip = achip->chip;
685 acpi_handle handle = ACPI_HANDLE(chip->dev);
688 INIT_LIST_HEAD(&achip->conns);
689 mutex_init(&achip->conn_lock);
690 status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
691 acpi_gpio_adr_space_handler,
693 if (ACPI_FAILURE(status))
694 dev_err(chip->dev, "Failed to install GPIO OpRegion handler\n");
697 static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
699 struct gpio_chip *chip = achip->chip;
700 acpi_handle handle = ACPI_HANDLE(chip->dev);
701 struct acpi_gpio_connection *conn, *tmp;
704 status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
705 acpi_gpio_adr_space_handler);
706 if (ACPI_FAILURE(status)) {
707 dev_err(chip->dev, "Failed to remove GPIO OpRegion handler\n");
711 list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) {
712 gpiochip_free_own_desc(conn->desc);
713 list_del(&conn->node);
718 void acpi_gpiochip_add(struct gpio_chip *chip)
720 struct acpi_gpio_chip *acpi_gpio;
724 if (!chip || !chip->dev)
727 handle = ACPI_HANDLE(chip->dev);
731 acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
734 "Failed to allocate memory for ACPI GPIO chip\n");
738 acpi_gpio->chip = chip;
740 status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
741 if (ACPI_FAILURE(status)) {
742 dev_err(chip->dev, "Failed to attach ACPI GPIO chip\n");
747 acpi_gpiochip_request_regions(acpi_gpio);
750 void acpi_gpiochip_remove(struct gpio_chip *chip)
752 struct acpi_gpio_chip *acpi_gpio;
756 if (!chip || !chip->dev)
759 handle = ACPI_HANDLE(chip->dev);
763 status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
764 if (ACPI_FAILURE(status)) {
765 dev_warn(chip->dev, "Failed to retrieve ACPI GPIO chip\n");
769 acpi_gpiochip_free_regions(acpi_gpio);
771 acpi_detach_data(handle, acpi_gpio_chip_dh);
775 static unsigned int acpi_gpio_package_count(const union acpi_object *obj)
777 const union acpi_object *element = obj->package.elements;
778 const union acpi_object *end = element + obj->package.count;
779 unsigned int count = 0;
781 while (element < end) {
782 if (element->type == ACPI_TYPE_LOCAL_REFERENCE)
790 static int acpi_find_gpio_count(struct acpi_resource *ares, void *data)
792 unsigned int *count = data;
794 if (ares->type == ACPI_RESOURCE_TYPE_GPIO)
795 *count += ares->data.gpio.pin_table_length;
801 * acpi_gpio_count - return the number of GPIOs associated with a
802 * device / function or -ENOENT if no GPIO has been
803 * assigned to the requested function.
804 * @dev: GPIO consumer, can be NULL for system-global GPIOs
805 * @con_id: function within the GPIO consumer
807 int acpi_gpio_count(struct device *dev, const char *con_id)
809 struct acpi_device *adev = ACPI_COMPANION(dev);
810 const union acpi_object *obj;
811 const struct acpi_gpio_mapping *gm;
817 /* Try first from _DSD */
818 for (i = 0; i < ARRAY_SIZE(gpio_suffixes); i++) {
819 if (con_id && strcmp(con_id, "gpios"))
820 snprintf(propname, sizeof(propname), "%s-%s",
821 con_id, gpio_suffixes[i]);
823 snprintf(propname, sizeof(propname), "%s",
826 ret = acpi_dev_get_property(adev, propname, ACPI_TYPE_ANY,
829 if (obj->type == ACPI_TYPE_LOCAL_REFERENCE)
831 else if (obj->type == ACPI_TYPE_PACKAGE)
832 count = acpi_gpio_package_count(obj);
833 } else if (adev->driver_gpios) {
834 for (gm = adev->driver_gpios; gm->name; gm++)
835 if (strcmp(propname, gm->name) == 0) {
844 /* Then from plain _CRS GPIOs */
846 struct list_head resource_list;
847 unsigned int crs_count = 0;
849 INIT_LIST_HEAD(&resource_list);
850 acpi_dev_get_resources(adev, &resource_list,
851 acpi_find_gpio_count, &crs_count);
852 acpi_dev_free_resource_list(&resource_list);