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 desc = gpiochip_request_own_desc(chip, pin, "ACPI:Event");
206 dev_err(chip->dev, "Failed to request GPIO\n");
210 gpiod_direction_input(desc);
212 ret = gpio_lock_as_irq(chip, pin);
214 dev_err(chip->dev, "Failed to lock GPIO as interrupt\n");
218 irq = gpiod_to_irq(desc);
220 dev_err(chip->dev, "Failed to translate GPIO to IRQ\n");
221 goto fail_unlock_irq;
224 irqflags = IRQF_ONESHOT;
225 if (agpio->triggering == ACPI_LEVEL_SENSITIVE) {
226 if (agpio->polarity == ACPI_ACTIVE_HIGH)
227 irqflags |= IRQF_TRIGGER_HIGH;
229 irqflags |= IRQF_TRIGGER_LOW;
231 switch (agpio->polarity) {
232 case ACPI_ACTIVE_HIGH:
233 irqflags |= IRQF_TRIGGER_RISING;
235 case ACPI_ACTIVE_LOW:
236 irqflags |= IRQF_TRIGGER_FALLING;
239 irqflags |= IRQF_TRIGGER_RISING |
240 IRQF_TRIGGER_FALLING;
245 event = kzalloc(sizeof(*event), GFP_KERNEL);
247 goto fail_unlock_irq;
249 event->handle = evt_handle;
254 ret = request_threaded_irq(event->irq, NULL, handler, irqflags,
255 "ACPI:Event", event);
257 dev_err(chip->dev, "Failed to setup interrupt handler for %d\n",
259 goto fail_free_event;
262 list_add_tail(&event->node, &acpi_gpio->events);
268 gpio_unlock_as_irq(chip, pin);
270 gpiochip_free_own_desc(desc);
276 * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
279 * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
280 * handled by ACPI event methods which need to be called from the GPIO
281 * chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
282 * gpio pins have acpi event methods and assigns interrupt handlers that calls
283 * the acpi event methods for those pins.
285 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
287 struct acpi_gpio_chip *acpi_gpio;
291 if (!chip->dev || !chip->to_irq)
294 handle = ACPI_HANDLE(chip->dev);
298 status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
299 if (ACPI_FAILURE(status))
302 INIT_LIST_HEAD(&acpi_gpio->events);
303 acpi_walk_resources(ACPI_HANDLE(chip->dev), "_AEI",
304 acpi_gpiochip_request_interrupt, acpi_gpio);
308 * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
311 * Free interrupts associated with GPIO ACPI event method for the given
314 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
316 struct acpi_gpio_chip *acpi_gpio;
317 struct acpi_gpio_event *event, *ep;
321 if (!chip->dev || !chip->to_irq)
324 handle = ACPI_HANDLE(chip->dev);
328 status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
329 if (ACPI_FAILURE(status))
332 list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
333 struct gpio_desc *desc;
335 free_irq(event->irq, event);
337 if (WARN_ON(IS_ERR(desc)))
339 gpio_unlock_as_irq(chip, event->pin);
340 gpiochip_free_own_desc(desc);
341 list_del(&event->node);
346 struct acpi_gpio_lookup {
347 struct acpi_gpio_info info;
349 struct gpio_desc *desc;
353 static int acpi_find_gpio(struct acpi_resource *ares, void *data)
355 struct acpi_gpio_lookup *lookup = data;
357 if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
360 if (lookup->n++ == lookup->index && !lookup->desc) {
361 const struct acpi_resource_gpio *agpio = &ares->data.gpio;
363 lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
364 agpio->pin_table[0]);
365 lookup->info.gpioint =
366 agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
367 lookup->info.active_low =
368 agpio->polarity == ACPI_ACTIVE_LOW;
375 * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
376 * @dev: pointer to a device to get GPIO from
377 * @index: index of GpioIo/GpioInt resource (starting from %0)
378 * @info: info pointer to fill in (optional)
380 * Function goes through ACPI resources for @dev and based on @index looks
381 * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
382 * and returns it. @index matches GpioIo/GpioInt resources only so if there
383 * are total %3 GPIO resources, the index goes from %0 to %2.
385 * If the GPIO cannot be translated or there is an error an ERR_PTR is
388 * Note: if the GPIO resource has multiple entries in the pin list, this
389 * function only returns the first.
391 struct gpio_desc *acpi_get_gpiod_by_index(struct device *dev, int index,
392 struct acpi_gpio_info *info)
394 struct acpi_gpio_lookup lookup;
395 struct list_head resource_list;
396 struct acpi_device *adev;
401 return ERR_PTR(-EINVAL);
403 handle = ACPI_HANDLE(dev);
404 if (!handle || acpi_bus_get_device(handle, &adev))
405 return ERR_PTR(-ENODEV);
407 memset(&lookup, 0, sizeof(lookup));
408 lookup.index = index;
410 INIT_LIST_HEAD(&resource_list);
411 ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio,
416 acpi_dev_free_resource_list(&resource_list);
418 if (lookup.desc && info)
421 return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT);
425 acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
426 u32 bits, u64 *value, void *handler_context,
427 void *region_context)
429 struct acpi_gpio_chip *achip = region_context;
430 struct gpio_chip *chip = achip->chip;
431 struct acpi_resource_gpio *agpio;
432 struct acpi_resource *ares;
433 int pin_index = (int)address;
439 status = acpi_buffer_to_resource(achip->conn_info.connection,
440 achip->conn_info.length, &ares);
441 if (ACPI_FAILURE(status))
444 if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) {
446 return AE_BAD_PARAMETER;
449 agpio = &ares->data.gpio;
450 pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP;
452 if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT &&
453 function == ACPI_WRITE)) {
455 return AE_BAD_PARAMETER;
458 length = min(agpio->pin_table_length, (u16)(pin_index + bits));
459 for (i = pin_index; i < length; ++i) {
460 unsigned pin = agpio->pin_table[i];
461 struct acpi_gpio_connection *conn;
462 struct gpio_desc *desc;
465 mutex_lock(&achip->conn_lock);
468 list_for_each_entry(conn, &achip->conns, node) {
469 if (conn->pin == pin) {
476 desc = gpiochip_request_own_desc(chip, pin,
480 mutex_unlock(&achip->conn_lock);
484 switch (agpio->io_restriction) {
485 case ACPI_IO_RESTRICT_INPUT:
486 gpiod_direction_input(desc);
488 case ACPI_IO_RESTRICT_OUTPUT:
490 * ACPI GPIO resources don't contain an
491 * initial value for the GPIO. Therefore we
492 * deduce that value from the pull field
493 * instead. If the pin is pulled up we
494 * assume default to be high, otherwise
497 gpiod_direction_output(desc, pull_up);
501 * Assume that the BIOS has configured the
502 * direction and pull accordingly.
507 conn = kzalloc(sizeof(*conn), GFP_KERNEL);
509 status = AE_NO_MEMORY;
510 gpiochip_free_own_desc(desc);
511 mutex_unlock(&achip->conn_lock);
517 list_add_tail(&conn->node, &achip->conns);
520 mutex_unlock(&achip->conn_lock);
522 if (function == ACPI_WRITE)
523 gpiod_set_raw_value_cansleep(desc,
524 !!((1 << i) & *value));
526 *value |= (u64)gpiod_get_raw_value_cansleep(desc) << i;
534 static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip)
536 struct gpio_chip *chip = achip->chip;
537 acpi_handle handle = ACPI_HANDLE(chip->dev);
540 INIT_LIST_HEAD(&achip->conns);
541 mutex_init(&achip->conn_lock);
542 status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
543 acpi_gpio_adr_space_handler,
545 if (ACPI_FAILURE(status))
546 dev_err(chip->dev, "Failed to install GPIO OpRegion handler\n");
549 static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
551 struct gpio_chip *chip = achip->chip;
552 acpi_handle handle = ACPI_HANDLE(chip->dev);
553 struct acpi_gpio_connection *conn, *tmp;
556 status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
557 acpi_gpio_adr_space_handler);
558 if (ACPI_FAILURE(status)) {
559 dev_err(chip->dev, "Failed to remove GPIO OpRegion handler\n");
563 list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) {
564 gpiochip_free_own_desc(conn->desc);
565 list_del(&conn->node);
570 void acpi_gpiochip_add(struct gpio_chip *chip)
572 struct acpi_gpio_chip *acpi_gpio;
576 if (!chip || !chip->dev)
579 handle = ACPI_HANDLE(chip->dev);
583 acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
586 "Failed to allocate memory for ACPI GPIO chip\n");
590 acpi_gpio->chip = chip;
592 status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
593 if (ACPI_FAILURE(status)) {
594 dev_err(chip->dev, "Failed to attach ACPI GPIO chip\n");
599 acpi_gpiochip_request_regions(acpi_gpio);
602 void acpi_gpiochip_remove(struct gpio_chip *chip)
604 struct acpi_gpio_chip *acpi_gpio;
608 if (!chip || !chip->dev)
611 handle = ACPI_HANDLE(chip->dev);
615 status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
616 if (ACPI_FAILURE(status)) {
617 dev_warn(chip->dev, "Failed to retrieve ACPI GPIO chip\n");
621 acpi_gpiochip_free_regions(acpi_gpio);
623 acpi_detach_data(handle, acpi_gpio_chip_dh);