[deliverable/linux.git] / drivers / gpio / gpiolib-acpi.c

/*
 * ACPI helpers for GPIO API
 *
 * Copyright (C) 2012, Intel Corporation
 * Authors: Mathias Nyman <mathias.nyman@linux.intel.com>
 *          Mika Westerberg <mika.westerberg@linux.intel.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/errno.h>
#include <linux/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include <linux/export.h>
#include <linux/acpi.h>
#include <linux/interrupt.h>

#include "gpiolib.h"

struct acpi_gpio_event {
	struct list_head node;
	acpi_handle handle;
	unsigned int pin;
	unsigned int irq;
};

struct acpi_gpio_chip {
	struct gpio_chip *chip;
	struct list_head events;
};

static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
{
	if (!gc->dev)
		return false;

	return ACPI_HANDLE(gc->dev) == data;
}

/**
 * acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API
 * @path:	ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
 * @pin:	ACPI GPIO pin number (0-based, controller-relative)
 *
 * Returns GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR
 * error value
 */

static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
{
	struct gpio_chip *chip;
	acpi_handle handle;
	acpi_status status;

	status = acpi_get_handle(NULL, path, &handle);
	if (ACPI_FAILURE(status))
		return ERR_PTR(-ENODEV);

	chip = gpiochip_find(handle, acpi_gpiochip_find);
	if (!chip)
		return ERR_PTR(-ENODEV);

	if (pin < 0 || pin > chip->ngpio)
		return ERR_PTR(-EINVAL);

	return gpiochip_get_desc(chip, pin);
}

static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
{
	struct acpi_gpio_event *event = data;

	acpi_evaluate_object(event->handle, NULL, NULL, NULL);

	return IRQ_HANDLED;
}

static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
{
	struct acpi_gpio_event *event = data;

	acpi_execute_simple_method(event->handle, NULL, event->pin);

	return IRQ_HANDLED;
}

static void acpi_gpio_chip_dh(acpi_handle handle, void *data)
{
	/* The address of this function is used as a key. */
}

static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
						   void *context)
{
	struct acpi_gpio_chip *acpi_gpio = context;
	struct gpio_chip *chip = acpi_gpio->chip;
	struct acpi_resource_gpio *agpio;
	acpi_handle handle, evt_handle;
	struct acpi_gpio_event *event;
	irq_handler_t handler = NULL;
	struct gpio_desc *desc;
	unsigned long irqflags;
	int ret, pin, irq;

	if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
		return AE_OK;

	agpio = &ares->data.gpio;
	if (agpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT)
		return AE_OK;

	handle = ACPI_HANDLE(chip->dev);
	pin = agpio->pin_table[0];

	if (pin <= 255) {
		char ev_name[5];
		sprintf(ev_name, "_%c%02X",
			agpio->triggering == ACPI_EDGE_SENSITIVE ? 'E' : 'L',
			pin);
		if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
			handler = acpi_gpio_irq_handler;
	}
	if (!handler) {
		if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
			handler = acpi_gpio_irq_handler_evt;
	}
	if (!handler)
		return AE_BAD_PARAMETER;

	desc = gpiochip_get_desc(chip, pin);
	if (IS_ERR(desc)) {
		dev_err(chip->dev, "Failed to get GPIO descriptor\n");
		return AE_ERROR;
	}

	ret = gpiochip_request_own_desc(desc, "ACPI:Event");
	if (ret) {
		dev_err(chip->dev, "Failed to request GPIO\n");
		return AE_ERROR;
	}

	gpiod_direction_input(desc);

	ret = gpiod_lock_as_irq(desc);
	if (ret) {
		dev_err(chip->dev, "Failed to lock GPIO as interrupt\n");
		goto fail_free_desc;
	}

	irq = gpiod_to_irq(desc);
	if (irq < 0) {
		dev_err(chip->dev, "Failed to translate GPIO to IRQ\n");
		goto fail_unlock_irq;
	}

	irqflags = IRQF_ONESHOT;
	if (agpio->triggering == ACPI_LEVEL_SENSITIVE) {
		if (agpio->polarity == ACPI_ACTIVE_HIGH)
			irqflags |= IRQF_TRIGGER_HIGH;
		else
			irqflags |= IRQF_TRIGGER_LOW;
	} else {
		switch (agpio->polarity) {
		case ACPI_ACTIVE_HIGH:
			irqflags |= IRQF_TRIGGER_RISING;
			break;
		case ACPI_ACTIVE_LOW:
			irqflags |= IRQF_TRIGGER_FALLING;
			break;
		default:
			irqflags |= IRQF_TRIGGER_RISING |
				    IRQF_TRIGGER_FALLING;
			break;
		}
	}

	event = kzalloc(sizeof(*event), GFP_KERNEL);
	if (!event)
		goto fail_unlock_irq;

	event->handle = evt_handle;
	event->irq = irq;
	event->pin = pin;

	ret = request_threaded_irq(event->irq, NULL, handler, irqflags,
				   "ACPI:Event", event);
	if (ret) {
		dev_err(chip->dev, "Failed to setup interrupt handler for %d\n",
			event->irq);
		goto fail_free_event;
	}

	list_add_tail(&event->node, &acpi_gpio->events);
	return AE_OK;

fail_free_event:
	kfree(event);
fail_unlock_irq:
	gpiod_unlock_as_irq(desc);
fail_free_desc:
	gpiochip_free_own_desc(desc);

	return AE_ERROR;
}

/**
 * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
 * @acpi_gpio:      ACPI GPIO chip
 *
 * ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
 * handled by ACPI event methods which need to be called from the GPIO
 * chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
 * gpio pins have acpi event methods and assigns interrupt handlers that calls
 * the acpi event methods for those pins.
 */
static void acpi_gpiochip_request_interrupts(struct acpi_gpio_chip *acpi_gpio)
{
	struct gpio_chip *chip = acpi_gpio->chip;

	if (!chip->dev || !chip->to_irq)
		return;

	INIT_LIST_HEAD(&acpi_gpio->events);
	acpi_walk_resources(ACPI_HANDLE(chip->dev), "_AEI",
			    acpi_gpiochip_request_interrupt, acpi_gpio);
}

/**
 * acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
 * @acpi_gpio:      ACPI GPIO chip
 *
 * Free interrupts associated with GPIO ACPI event method for the given
 * GPIO chip.
 */
static void acpi_gpiochip_free_interrupts(struct acpi_gpio_chip *acpi_gpio)
{
	struct acpi_gpio_event *event, *ep;
	struct gpio_chip *chip = acpi_gpio->chip;

	if (!chip->dev || !chip->to_irq)
		return;

	list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
		struct gpio_desc *desc;

		free_irq(event->irq, event);
		desc = gpiochip_get_desc(chip, event->pin);
		if (WARN_ON(IS_ERR(desc)))
			continue;
		gpiod_unlock_as_irq(desc);
		gpiochip_free_own_desc(desc);
		list_del(&event->node);
		kfree(event);
	}
}

struct acpi_gpio_lookup {
	struct acpi_gpio_info info;
	int index;
	struct gpio_desc *desc;
	int n;
};

static int acpi_find_gpio(struct acpi_resource *ares, void *data)
{
	struct acpi_gpio_lookup *lookup = data;

	if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
		return 1;

	if (lookup->n++ == lookup->index && !lookup->desc) {
		const struct acpi_resource_gpio *agpio = &ares->data.gpio;

		lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
					      agpio->pin_table[0]);
		lookup->info.gpioint =
			agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
		lookup->info.active_low =
			agpio->polarity == ACPI_ACTIVE_LOW;
	}

	return 1;
}

/**
 * acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
 * @dev: pointer to a device to get GPIO from
 * @index: index of GpioIo/GpioInt resource (starting from %0)
 * @info: info pointer to fill in (optional)
 *
 * Function goes through ACPI resources for @dev and based on @index looks
 * up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
 * and returns it. @index matches GpioIo/GpioInt resources only so if there
 * are total %3 GPIO resources, the index goes from %0 to %2.
 *
 * If the GPIO cannot be translated or there is an error an ERR_PTR is
 * returned.
 *
 * Note: if the GPIO resource has multiple entries in the pin list, this
 * function only returns the first.
 */
struct gpio_desc *acpi_get_gpiod_by_index(struct device *dev, int index,
					  struct acpi_gpio_info *info)
{
	struct acpi_gpio_lookup lookup;
	struct list_head resource_list;
	struct acpi_device *adev;
	acpi_handle handle;
	int ret;

	if (!dev)
		return ERR_PTR(-EINVAL);

	handle = ACPI_HANDLE(dev);
	if (!handle || acpi_bus_get_device(handle, &adev))
		return ERR_PTR(-ENODEV);

	memset(&lookup, 0, sizeof(lookup));
	lookup.index = index;

	INIT_LIST_HEAD(&resource_list);
	ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio,
				     &lookup);
	if (ret < 0)
		return ERR_PTR(ret);

	acpi_dev_free_resource_list(&resource_list);

	if (lookup.desc && info)
		*info = lookup.info;

	return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT);
}

void acpi_gpiochip_add(struct gpio_chip *chip)
{
	struct acpi_gpio_chip *acpi_gpio;
	acpi_handle handle;
	acpi_status status;

	handle = ACPI_HANDLE(chip->dev);
	if (!handle)
		return;

	acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
	if (!acpi_gpio) {
		dev_err(chip->dev,
			"Failed to allocate memory for ACPI GPIO chip\n");
		return;
	}

	acpi_gpio->chip = chip;

	status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
	if (ACPI_FAILURE(status)) {
		dev_err(chip->dev, "Failed to attach ACPI GPIO chip\n");
		kfree(acpi_gpio);
		return;
	}

	acpi_gpiochip_request_interrupts(acpi_gpio);
}

void acpi_gpiochip_remove(struct gpio_chip *chip)
{
	struct acpi_gpio_chip *acpi_gpio;
	acpi_handle handle;
	acpi_status status;

	handle = ACPI_HANDLE(chip->dev);
	if (!handle)
		return;

	status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
	if (ACPI_FAILURE(status)) {
		dev_warn(chip->dev, "Failed to retrieve ACPI GPIO chip\n");
		return;
	}

	acpi_gpiochip_free_interrupts(acpi_gpio);

	acpi_detach_data(handle, acpi_gpio_chip_dh);
	kfree(acpi_gpio);
}
Commit	Line	Data
e29482e8 MN	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>
936e15dd	14	#include <linux/gpio/consumer.h>
5ccff852	15	#include <linux/gpio/driver.h>
e29482e8	16	#include <linux/export.h>
e29482e8	17	#include <linux/acpi.h>
0d1c28a4	18	#include <linux/interrupt.h>
e29482e8	19
5ccff852 MW	20	#include "gpiolib.h"
5ccff852 MW	21
4b01a14b	22	struct acpi_gpio_event {
7fc7acb9	23	struct list_head node;
4b01a14b	24	acpi_handle handle;
7fc7acb9 RW	25	unsigned int pin;
	26	unsigned int irq;
	27	};
	28
aa92b6f6 MW	29	struct acpi_gpio_chip {
aa92b6f6 MW	30	struct gpio_chip *chip;
4b01a14b	31	struct list_head events;
aa92b6f6 MW	32	};
aa92b6f6 MW	33
e29482e8 MN	34	static int acpi_gpiochip_find(struct gpio_chip gc, void data)
	35	{
	36	if (!gc->dev)
	37	return false;
	38
	39	return ACPI_HANDLE(gc->dev) == data;
	40	}
	41
	42	/**
936e15dd	43	* acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API
e29482e8 MN	44	* @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
	45	* @pin: ACPI GPIO pin number (0-based, controller-relative)
	46	*
936e15dd MW	47	* Returns GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR
936e15dd MW	48	* error value
e29482e8 MN	49	*/
e29482e8 MN	50
936e15dd	51	static struct gpio_desc acpi_get_gpiod(char path, int pin)
e29482e8 MN	52	{
	53	struct gpio_chip *chip;
	54	acpi_handle handle;
	55	acpi_status status;
	56
	57	status = acpi_get_handle(NULL, path, &handle);
	58	if (ACPI_FAILURE(status))
936e15dd	59	return ERR_PTR(-ENODEV);
e29482e8 MN	60
	61	chip = gpiochip_find(handle, acpi_gpiochip_find);
	62	if (!chip)
936e15dd	63	return ERR_PTR(-ENODEV);
e29482e8	64
936e15dd MW	65	if (pin < 0 \|\| pin > chip->ngpio)
936e15dd MW	66	return ERR_PTR(-EINVAL);
e29482e8	67
390d82e3	68	return gpiochip_get_desc(chip, pin);
e29482e8	69	}
0d1c28a4	70
0d1c28a4 MN	71	static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
0d1c28a4 MN	72	{
6072b9dc	73	struct acpi_gpio_event *event = data;
0d1c28a4	74
6072b9dc	75	acpi_evaluate_object(event->handle, NULL, NULL, NULL);
0d1c28a4 MN	76
	77	return IRQ_HANDLED;
	78	}
	79
7fc7acb9 RW	80	static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
7fc7acb9 RW	81	{
4b01a14b	82	struct acpi_gpio_event *event = data;
7fc7acb9	83
4b01a14b	84	acpi_execute_simple_method(event->handle, NULL, event->pin);
7fc7acb9 RW	85
	86	return IRQ_HANDLED;
	87	}
	88
aa92b6f6	89	static void acpi_gpio_chip_dh(acpi_handle handle, void *data)
7fc7acb9 RW	90	{
	91	/* The address of this function is used as a key. */
	92	}
	93
6072b9dc MW	94	static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
6072b9dc MW	95	void *context)
0d1c28a4	96	{
6072b9dc	97	struct acpi_gpio_chip *acpi_gpio = context;
aa92b6f6	98	struct gpio_chip *chip = acpi_gpio->chip;
6072b9dc	99	struct acpi_resource_gpio *agpio;
7fc7acb9	100	acpi_handle handle, evt_handle;
6072b9dc MW	101	struct acpi_gpio_event *event;
	102	irq_handler_t handler = NULL;
	103	struct gpio_desc *desc;
	104	unsigned long irqflags;
	105	int ret, pin, irq;
0d1c28a4	106
6072b9dc MW	107	if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
	108	return AE_OK;
	109
	110	agpio = &ares->data.gpio;
	111	if (agpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT)
	112	return AE_OK;
0d1c28a4 MN	113
0d1c28a4 MN	114	handle = ACPI_HANDLE(chip->dev);
6072b9dc MW	115	pin = agpio->pin_table[0];
	116
	117	if (pin <= 255) {
	118	char ev_name[5];
	119	sprintf(ev_name, "_%c%02X",
	120	agpio->triggering == ACPI_EDGE_SENSITIVE ? 'E' : 'L',
	121	pin);
	122	if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
	123	handler = acpi_gpio_irq_handler;
	124	}
	125	if (!handler) {
	126	if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
	127	handler = acpi_gpio_irq_handler_evt;
	128	}
	129	if (!handler)
	130	return AE_BAD_PARAMETER;
0d1c28a4	131
6072b9dc MW	132	desc = gpiochip_get_desc(chip, pin);
	133	if (IS_ERR(desc)) {
	134	dev_err(chip->dev, "Failed to get GPIO descriptor\n");
	135	return AE_ERROR;
	136	}
0d1c28a4	137
6072b9dc MW	138	ret = gpiochip_request_own_desc(desc, "ACPI:Event");
	139	if (ret) {
	140	dev_err(chip->dev, "Failed to request GPIO\n");
	141	return AE_ERROR;
	142	}
0d1c28a4	143
6072b9dc	144	gpiod_direction_input(desc);
0d1c28a4	145
6072b9dc MW	146	ret = gpiod_lock_as_irq(desc);
	147	if (ret) {
	148	dev_err(chip->dev, "Failed to lock GPIO as interrupt\n");
	149	goto fail_free_desc;
	150	}
0d1c28a4	151
6072b9dc MW	152	irq = gpiod_to_irq(desc);
	153	if (irq < 0) {
	154	dev_err(chip->dev, "Failed to translate GPIO to IRQ\n");
	155	goto fail_unlock_irq;
	156	}
7fc7acb9	157
6072b9dc MW	158	irqflags = IRQF_ONESHOT;
	159	if (agpio->triggering == ACPI_LEVEL_SENSITIVE) {
	160	if (agpio->polarity == ACPI_ACTIVE_HIGH)
	161	irqflags \|= IRQF_TRIGGER_HIGH;
	162	else
	163	irqflags \|= IRQF_TRIGGER_LOW;
	164	} else {
	165	switch (agpio->polarity) {
	166	case ACPI_ACTIVE_HIGH:
	167	irqflags \|= IRQF_TRIGGER_RISING;
	168	break;
	169	case ACPI_ACTIVE_LOW:
	170	irqflags \|= IRQF_TRIGGER_FALLING;
	171	break;
	172	default:
	173	irqflags \|= IRQF_TRIGGER_RISING \|
	174	IRQF_TRIGGER_FALLING;
	175	break;
7fc7acb9	176	}
6072b9dc	177	}
aa92b6f6	178
6072b9dc MW	179	event = kzalloc(sizeof(*event), GFP_KERNEL);
	180	if (!event)
	181	goto fail_unlock_irq;
7fc7acb9	182
6072b9dc MW	183	event->handle = evt_handle;
	184	event->irq = irq;
	185	event->pin = pin;
7fc7acb9	186
6072b9dc MW	187	ret = request_threaded_irq(event->irq, NULL, handler, irqflags,
	188	"ACPI:Event", event);
	189	if (ret) {
	190	dev_err(chip->dev, "Failed to setup interrupt handler for %d\n",
	191	event->irq);
	192	goto fail_free_event;
0d1c28a4	193	}
6072b9dc MW	194
	195	list_add_tail(&event->node, &acpi_gpio->events);
	196	return AE_OK;
	197
	198	fail_free_event:
	199	kfree(event);
	200	fail_unlock_irq:
	201	gpiod_unlock_as_irq(desc);
	202	fail_free_desc:
	203	gpiochip_free_own_desc(desc);
	204
	205	return AE_ERROR;
0d1c28a4	206	}
7fc7acb9	207
70b53411	208	/**
6072b9dc	209	* acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
aa92b6f6	210	* @acpi_gpio: ACPI GPIO chip
70b53411	211	*
6072b9dc MW	212	* ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
	213	* handled by ACPI event methods which need to be called from the GPIO
	214	* chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
	215	* gpio pins have acpi event methods and assigns interrupt handlers that calls
	216	* the acpi event methods for those pins.
	217	*/
	218	static void acpi_gpiochip_request_interrupts(struct acpi_gpio_chip *acpi_gpio)
	219	{
	220	struct gpio_chip *chip = acpi_gpio->chip;
	221
	222	if (!chip->dev \|\| !chip->to_irq)
	223	return;
	224
	225	INIT_LIST_HEAD(&acpi_gpio->events);
	226	acpi_walk_resources(ACPI_HANDLE(chip->dev), "_AEI",
	227	acpi_gpiochip_request_interrupt, acpi_gpio);
	228	}
	229
	230	/**
	231	* acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
	232	* @acpi_gpio: ACPI GPIO chip
70b53411	233	*
6072b9dc MW	234	* Free interrupts associated with GPIO ACPI event method for the given
6072b9dc MW	235	* GPIO chip.
70b53411	236	*/
aa92b6f6	237	static void acpi_gpiochip_free_interrupts(struct acpi_gpio_chip *acpi_gpio)
70b53411	238	{
4b01a14b	239	struct acpi_gpio_event event, ep;
aa92b6f6	240	struct gpio_chip *chip = acpi_gpio->chip;
70b53411 MW	241
	242	if (!chip->dev \|\| !chip->to_irq)
	243	return;
	244
4b01a14b	245	list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
6072b9dc MW	246	struct gpio_desc *desc;
	247
	248	free_irq(event->irq, event);
	249	desc = gpiochip_get_desc(chip, event->pin);
	250	if (WARN_ON(IS_ERR(desc)))
	251	continue;
	252	gpiod_unlock_as_irq(desc);
	253	gpiochip_free_own_desc(desc);
4b01a14b MW	254	list_del(&event->node);
4b01a14b MW	255	kfree(event);
70b53411	256	}
70b53411	257	}
70b53411	258
12028d2d MW	259	struct acpi_gpio_lookup {
	260	struct acpi_gpio_info info;
	261	int index;
936e15dd	262	struct gpio_desc *desc;
12028d2d MW	263	int n;
	264	};
	265
	266	static int acpi_find_gpio(struct acpi_resource ares, void data)
	267	{
	268	struct acpi_gpio_lookup *lookup = data;
	269
	270	if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
	271	return 1;
	272
936e15dd	273	if (lookup->n++ == lookup->index && !lookup->desc) {
12028d2d MW	274	const struct acpi_resource_gpio *agpio = &ares->data.gpio;
12028d2d MW	275
936e15dd MW	276	lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
936e15dd MW	277	agpio->pin_table[0]);
12028d2d MW	278	lookup->info.gpioint =
12028d2d MW	279	agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
e01f440a MW	280	lookup->info.active_low =
e01f440a MW	281	agpio->polarity == ACPI_ACTIVE_LOW;
12028d2d MW	282	}
	283
	284	return 1;
	285	}
	286
	287	/**
936e15dd	288	* acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
12028d2d MW	289	* @dev: pointer to a device to get GPIO from
	290	* @index: index of GpioIo/GpioInt resource (starting from %0)
	291	* @info: info pointer to fill in (optional)
	292	*
	293	* Function goes through ACPI resources for @dev and based on @index looks
936e15dd	294	* up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
12028d2d MW	295	* and returns it. @index matches GpioIo/GpioInt resources only so if there
	296	* are total %3 GPIO resources, the index goes from %0 to %2.
	297	*
936e15dd	298	* If the GPIO cannot be translated or there is an error an ERR_PTR is
12028d2d MW	299	* returned.
	300	*
	301	* Note: if the GPIO resource has multiple entries in the pin list, this
	302	* function only returns the first.
	303	*/
936e15dd MW	304	struct gpio_desc acpi_get_gpiod_by_index(struct device dev, int index,
936e15dd MW	305	struct acpi_gpio_info *info)
12028d2d MW	306	{
	307	struct acpi_gpio_lookup lookup;
	308	struct list_head resource_list;
	309	struct acpi_device *adev;
	310	acpi_handle handle;
	311	int ret;
	312
	313	if (!dev)
936e15dd	314	return ERR_PTR(-EINVAL);
12028d2d MW	315
	316	handle = ACPI_HANDLE(dev);
	317	if (!handle \|\| acpi_bus_get_device(handle, &adev))
936e15dd	318	return ERR_PTR(-ENODEV);
12028d2d MW	319
	320	memset(&lookup, 0, sizeof(lookup));
	321	lookup.index = index;
12028d2d MW	322
	323	INIT_LIST_HEAD(&resource_list);
	324	ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio,
	325	&lookup);
	326	if (ret < 0)
936e15dd	327	return ERR_PTR(ret);
12028d2d MW	328
	329	acpi_dev_free_resource_list(&resource_list);
	330
936e15dd	331	if (lookup.desc && info)
12028d2d MW	332	*info = lookup.info;
12028d2d MW	333
a00580c2	334	return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT);
12028d2d	335	}
664e3e5a MW	336
	337	void acpi_gpiochip_add(struct gpio_chip *chip)
	338	{
aa92b6f6 MW	339	struct acpi_gpio_chip *acpi_gpio;
	340	acpi_handle handle;
	341	acpi_status status;
	342
	343	handle = ACPI_HANDLE(chip->dev);
	344	if (!handle)
	345	return;
	346
	347	acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
	348	if (!acpi_gpio) {
	349	dev_err(chip->dev,
	350	"Failed to allocate memory for ACPI GPIO chip\n");
	351	return;
	352	}
	353
	354	acpi_gpio->chip = chip;
	355
	356	status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
	357	if (ACPI_FAILURE(status)) {
	358	dev_err(chip->dev, "Failed to attach ACPI GPIO chip\n");
	359	kfree(acpi_gpio);
	360	return;
	361	}
	362
	363	acpi_gpiochip_request_interrupts(acpi_gpio);
664e3e5a MW	364	}
	365
	366	void acpi_gpiochip_remove(struct gpio_chip *chip)
	367	{
aa92b6f6 MW	368	struct acpi_gpio_chip *acpi_gpio;
	369	acpi_handle handle;
	370	acpi_status status;
	371
	372	handle = ACPI_HANDLE(chip->dev);
	373	if (!handle)
	374	return;
	375
	376	status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
	377	if (ACPI_FAILURE(status)) {
	378	dev_warn(chip->dev, "Failed to retrieve ACPI GPIO chip\n");
	379	return;
	380	}
	381
	382	acpi_gpiochip_free_interrupts(acpi_gpio);
	383
	384	acpi_detach_data(handle, acpi_gpio_chip_dh);
	385	kfree(acpi_gpio);
664e3e5a	386	}