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