[mirror_ubuntu-focal-kernel.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 <linux/mutex.h>

#include "gpiolib.h"

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

struct acpi_gpio_connection {
	struct list_head node;
	struct gpio_desc *desc;
};

struct acpi_gpio_chip {
	/*
	 * ACPICA requires that the first field of the context parameter
	 * passed to acpi_install_address_space_handler() is large enough
	 * to hold struct acpi_connection_info.
	 */
	struct acpi_connection_info conn_info;
	struct list_head conns;
	struct mutex conn_lock;
	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 = gpio_lock_as_irq(chip, pin);
	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:
	gpio_unlock_as_irq(chip, pin);
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->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->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;
		gpio_unlock_as_irq(chip, event->pin);
		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);
}

static acpi_status
acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
			    u32 bits, u64 *value, void *handler_context,
			    void *region_context)
{
	struct acpi_gpio_chip *achip = region_context;
	struct gpio_chip *chip = achip->chip;
	struct acpi_resource_gpio *agpio;
	struct acpi_resource *ares;
	acpi_status status;
	bool pull_up;
	int i;

	status = acpi_buffer_to_resource(achip->conn_info.connection,
					 achip->conn_info.length, &ares);
	if (ACPI_FAILURE(status))
		return status;

	if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) {
		ACPI_FREE(ares);
		return AE_BAD_PARAMETER;
	}

	agpio = &ares->data.gpio;
	pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP;

	if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT &&
	    function == ACPI_WRITE)) {
		ACPI_FREE(ares);
		return AE_BAD_PARAMETER;
	}

	for (i = 0; i < agpio->pin_table_length; i++) {
		unsigned pin = agpio->pin_table[i];
		struct acpi_gpio_connection *conn;
		struct gpio_desc *desc;
		bool found;

		desc = gpiochip_get_desc(chip, pin);
		if (IS_ERR(desc)) {
			status = AE_ERROR;
			goto out;
		}

		mutex_lock(&achip->conn_lock);

		found = false;
		list_for_each_entry(conn, &achip->conns, node) {
			if (conn->desc == desc) {
				found = true;
				break;
			}
		}
		if (!found) {
			int ret;

			ret = gpiochip_request_own_desc(desc, "ACPI:OpRegion");
			if (ret) {
				status = AE_ERROR;
				mutex_unlock(&achip->conn_lock);
				goto out;
			}

			switch (agpio->io_restriction) {
			case ACPI_IO_RESTRICT_INPUT:
				gpiod_direction_input(desc);
				break;
			case ACPI_IO_RESTRICT_OUTPUT:
				/*
				 * ACPI GPIO resources don't contain an
				 * initial value for the GPIO. Therefore we
				 * deduce that value from the pull field
				 * instead. If the pin is pulled up we
				 * assume default to be high, otherwise
				 * low.
				 */
				gpiod_direction_output(desc, pull_up);
				break;
			default:
				/*
				 * Assume that the BIOS has configured the
				 * direction and pull accordingly.
				 */
				break;
			}

			conn = kzalloc(sizeof(*conn), GFP_KERNEL);
			if (!conn) {
				status = AE_NO_MEMORY;
				gpiochip_free_own_desc(desc);
				mutex_unlock(&achip->conn_lock);
				goto out;
			}

			conn->desc = desc;
			list_add_tail(&conn->node, &achip->conns);
		}

		mutex_unlock(&achip->conn_lock);

		if (function == ACPI_WRITE)
			gpiod_set_raw_value_cansleep(desc,
						     !!((1 << i) & *value));
		else
			*value |= (u64)gpiod_get_raw_value_cansleep(desc) << i;
	}

out:
	ACPI_FREE(ares);
	return status;
}

static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip)
{
	struct gpio_chip *chip = achip->chip;
	acpi_handle handle = ACPI_HANDLE(chip->dev);
	acpi_status status;

	INIT_LIST_HEAD(&achip->conns);
	mutex_init(&achip->conn_lock);
	status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
						    acpi_gpio_adr_space_handler,
						    NULL, achip);
	if (ACPI_FAILURE(status))
		dev_err(chip->dev, "Failed to install GPIO OpRegion handler\n");
}

static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
{
	struct gpio_chip *chip = achip->chip;
	acpi_handle handle = ACPI_HANDLE(chip->dev);
	struct acpi_gpio_connection *conn, *tmp;
	acpi_status status;

	status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
						   acpi_gpio_adr_space_handler);
	if (ACPI_FAILURE(status)) {
		dev_err(chip->dev, "Failed to remove GPIO OpRegion handler\n");
		return;
	}

	list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) {
		gpiochip_free_own_desc(conn->desc);
		list_del(&conn->node);
		kfree(conn);
	}
}

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

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

	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);
	acpi_gpiochip_request_regions(acpi_gpio);
}

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

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

	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_regions(acpi_gpio);
	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>
473ed7be	19	#include <linux/mutex.h>
e29482e8	20
5ccff852 MW	21	#include "gpiolib.h"
5ccff852 MW	22
4b01a14b	23	struct acpi_gpio_event {
7fc7acb9	24	struct list_head node;
4b01a14b	25	acpi_handle handle;
7fc7acb9 RW	26	unsigned int pin;
	27	unsigned int irq;
	28	};
	29
473ed7be MW	30	struct acpi_gpio_connection {
	31	struct list_head node;
	32	struct gpio_desc *desc;
	33	};
	34
aa92b6f6	35	struct acpi_gpio_chip {
473ed7be MW	36	/*
	37	* ACPICA requires that the first field of the context parameter
	38	* passed to acpi_install_address_space_handler() is large enough
	39	* to hold struct acpi_connection_info.
	40	*/
	41	struct acpi_connection_info conn_info;
	42	struct list_head conns;
	43	struct mutex conn_lock;
aa92b6f6	44	struct gpio_chip *chip;
4b01a14b	45	struct list_head events;
aa92b6f6 MW	46	};
aa92b6f6 MW	47
e29482e8 MN	48	static int acpi_gpiochip_find(struct gpio_chip gc, void data)
	49	{
	50	if (!gc->dev)
	51	return false;
	52
	53	return ACPI_HANDLE(gc->dev) == data;
	54	}
	55
	56	/**
936e15dd	57	* acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API
e29482e8 MN	58	* @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
	59	* @pin: ACPI GPIO pin number (0-based, controller-relative)
	60	*
936e15dd MW	61	* Returns GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR
936e15dd MW	62	* error value
e29482e8 MN	63	*/
e29482e8 MN	64
936e15dd	65	static struct gpio_desc acpi_get_gpiod(char path, int pin)
e29482e8 MN	66	{
	67	struct gpio_chip *chip;
	68	acpi_handle handle;
	69	acpi_status status;
	70
	71	status = acpi_get_handle(NULL, path, &handle);
	72	if (ACPI_FAILURE(status))
936e15dd	73	return ERR_PTR(-ENODEV);
e29482e8 MN	74
	75	chip = gpiochip_find(handle, acpi_gpiochip_find);
	76	if (!chip)
936e15dd	77	return ERR_PTR(-ENODEV);
e29482e8	78
936e15dd MW	79	if (pin < 0 \|\| pin > chip->ngpio)
936e15dd MW	80	return ERR_PTR(-EINVAL);
e29482e8	81
390d82e3	82	return gpiochip_get_desc(chip, pin);
e29482e8	83	}
0d1c28a4	84
0d1c28a4 MN	85	static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
0d1c28a4 MN	86	{
6072b9dc	87	struct acpi_gpio_event *event = data;
0d1c28a4	88
6072b9dc	89	acpi_evaluate_object(event->handle, NULL, NULL, NULL);
0d1c28a4 MN	90
	91	return IRQ_HANDLED;
	92	}
	93
7fc7acb9 RW	94	static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
7fc7acb9 RW	95	{
4b01a14b	96	struct acpi_gpio_event *event = data;
7fc7acb9	97
4b01a14b	98	acpi_execute_simple_method(event->handle, NULL, event->pin);
7fc7acb9 RW	99
	100	return IRQ_HANDLED;
	101	}
	102
aa92b6f6	103	static void acpi_gpio_chip_dh(acpi_handle handle, void *data)
7fc7acb9 RW	104	{
	105	/* The address of this function is used as a key. */
	106	}
	107
6072b9dc MW	108	static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
6072b9dc MW	109	void *context)
0d1c28a4	110	{
6072b9dc	111	struct acpi_gpio_chip *acpi_gpio = context;
aa92b6f6	112	struct gpio_chip *chip = acpi_gpio->chip;
6072b9dc	113	struct acpi_resource_gpio *agpio;
7fc7acb9	114	acpi_handle handle, evt_handle;
6072b9dc MW	115	struct acpi_gpio_event *event;
	116	irq_handler_t handler = NULL;
	117	struct gpio_desc *desc;
	118	unsigned long irqflags;
	119	int ret, pin, irq;
0d1c28a4	120
6072b9dc MW	121	if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
	122	return AE_OK;
	123
	124	agpio = &ares->data.gpio;
	125	if (agpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT)
	126	return AE_OK;
0d1c28a4 MN	127
0d1c28a4 MN	128	handle = ACPI_HANDLE(chip->dev);
6072b9dc MW	129	pin = agpio->pin_table[0];
	130
	131	if (pin <= 255) {
	132	char ev_name[5];
	133	sprintf(ev_name, "_%c%02X",
	134	agpio->triggering == ACPI_EDGE_SENSITIVE ? 'E' : 'L',
	135	pin);
	136	if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
	137	handler = acpi_gpio_irq_handler;
	138	}
	139	if (!handler) {
	140	if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
	141	handler = acpi_gpio_irq_handler_evt;
	142	}
	143	if (!handler)
	144	return AE_BAD_PARAMETER;
0d1c28a4	145
6072b9dc MW	146	desc = gpiochip_get_desc(chip, pin);
	147	if (IS_ERR(desc)) {
	148	dev_err(chip->dev, "Failed to get GPIO descriptor\n");
	149	return AE_ERROR;
	150	}
0d1c28a4	151
6072b9dc MW	152	ret = gpiochip_request_own_desc(desc, "ACPI:Event");
	153	if (ret) {
	154	dev_err(chip->dev, "Failed to request GPIO\n");
	155	return AE_ERROR;
	156	}
0d1c28a4	157
6072b9dc	158	gpiod_direction_input(desc);
0d1c28a4	159
d74be6df	160	ret = gpio_lock_as_irq(chip, pin);
6072b9dc MW	161	if (ret) {
	162	dev_err(chip->dev, "Failed to lock GPIO as interrupt\n");
	163	goto fail_free_desc;
	164	}
0d1c28a4	165
6072b9dc MW	166	irq = gpiod_to_irq(desc);
	167	if (irq < 0) {
	168	dev_err(chip->dev, "Failed to translate GPIO to IRQ\n");
	169	goto fail_unlock_irq;
	170	}
7fc7acb9	171
6072b9dc MW	172	irqflags = IRQF_ONESHOT;
	173	if (agpio->triggering == ACPI_LEVEL_SENSITIVE) {
	174	if (agpio->polarity == ACPI_ACTIVE_HIGH)
	175	irqflags \|= IRQF_TRIGGER_HIGH;
	176	else
	177	irqflags \|= IRQF_TRIGGER_LOW;
	178	} else {
	179	switch (agpio->polarity) {
	180	case ACPI_ACTIVE_HIGH:
	181	irqflags \|= IRQF_TRIGGER_RISING;
	182	break;
	183	case ACPI_ACTIVE_LOW:
	184	irqflags \|= IRQF_TRIGGER_FALLING;
	185	break;
	186	default:
	187	irqflags \|= IRQF_TRIGGER_RISING \|
	188	IRQF_TRIGGER_FALLING;
	189	break;
7fc7acb9	190	}
6072b9dc	191	}
aa92b6f6	192
6072b9dc MW	193	event = kzalloc(sizeof(*event), GFP_KERNEL);
	194	if (!event)
	195	goto fail_unlock_irq;
7fc7acb9	196
6072b9dc MW	197	event->handle = evt_handle;
	198	event->irq = irq;
	199	event->pin = pin;
7fc7acb9	200
6072b9dc MW	201	ret = request_threaded_irq(event->irq, NULL, handler, irqflags,
	202	"ACPI:Event", event);
	203	if (ret) {
	204	dev_err(chip->dev, "Failed to setup interrupt handler for %d\n",
	205	event->irq);
	206	goto fail_free_event;
0d1c28a4	207	}
6072b9dc MW	208
	209	list_add_tail(&event->node, &acpi_gpio->events);
	210	return AE_OK;
	211
	212	fail_free_event:
	213	kfree(event);
	214	fail_unlock_irq:
d74be6df	215	gpio_unlock_as_irq(chip, pin);
6072b9dc MW	216	fail_free_desc:
	217	gpiochip_free_own_desc(desc);
	218
	219	return AE_ERROR;
0d1c28a4	220	}
7fc7acb9	221
70b53411	222	/**
6072b9dc	223	* acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
aa92b6f6	224	* @acpi_gpio: ACPI GPIO chip
70b53411	225	*
6072b9dc MW	226	* ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
	227	* handled by ACPI event methods which need to be called from the GPIO
	228	* chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
	229	* gpio pins have acpi event methods and assigns interrupt handlers that calls
	230	* the acpi event methods for those pins.
	231	*/
	232	static void acpi_gpiochip_request_interrupts(struct acpi_gpio_chip *acpi_gpio)
	233	{
	234	struct gpio_chip *chip = acpi_gpio->chip;
	235
e9595f84	236	if (!chip->to_irq)
6072b9dc MW	237	return;
	238
	239	INIT_LIST_HEAD(&acpi_gpio->events);
	240	acpi_walk_resources(ACPI_HANDLE(chip->dev), "_AEI",
	241	acpi_gpiochip_request_interrupt, acpi_gpio);
	242	}
	243
	244	/**
	245	* acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
	246	* @acpi_gpio: ACPI GPIO chip
70b53411	247	*
6072b9dc MW	248	* Free interrupts associated with GPIO ACPI event method for the given
6072b9dc MW	249	* GPIO chip.
70b53411	250	*/
aa92b6f6	251	static void acpi_gpiochip_free_interrupts(struct acpi_gpio_chip *acpi_gpio)
70b53411	252	{
4b01a14b	253	struct acpi_gpio_event event, ep;
aa92b6f6	254	struct gpio_chip *chip = acpi_gpio->chip;
70b53411	255
e9595f84	256	if (!chip->to_irq)
70b53411 MW	257	return;
70b53411 MW	258
4b01a14b	259	list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
6072b9dc MW	260	struct gpio_desc *desc;
	261
	262	free_irq(event->irq, event);
	263	desc = gpiochip_get_desc(chip, event->pin);
	264	if (WARN_ON(IS_ERR(desc)))
	265	continue;
d74be6df	266	gpio_unlock_as_irq(chip, event->pin);
6072b9dc	267	gpiochip_free_own_desc(desc);
4b01a14b MW	268	list_del(&event->node);
4b01a14b MW	269	kfree(event);
70b53411	270	}
70b53411	271	}
70b53411	272
12028d2d MW	273	struct acpi_gpio_lookup {
	274	struct acpi_gpio_info info;
	275	int index;
936e15dd	276	struct gpio_desc *desc;
12028d2d MW	277	int n;
	278	};
	279
	280	static int acpi_find_gpio(struct acpi_resource ares, void data)
	281	{
	282	struct acpi_gpio_lookup *lookup = data;
	283
	284	if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
	285	return 1;
	286
936e15dd	287	if (lookup->n++ == lookup->index && !lookup->desc) {
12028d2d MW	288	const struct acpi_resource_gpio *agpio = &ares->data.gpio;
12028d2d MW	289
936e15dd MW	290	lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
936e15dd MW	291	agpio->pin_table[0]);
12028d2d MW	292	lookup->info.gpioint =
12028d2d MW	293	agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
e01f440a MW	294	lookup->info.active_low =
e01f440a MW	295	agpio->polarity == ACPI_ACTIVE_LOW;
12028d2d MW	296	}
	297
	298	return 1;
	299	}
	300
	301	/**
936e15dd	302	* acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
12028d2d MW	303	* @dev: pointer to a device to get GPIO from
	304	* @index: index of GpioIo/GpioInt resource (starting from %0)
	305	* @info: info pointer to fill in (optional)
	306	*
	307	* Function goes through ACPI resources for @dev and based on @index looks
936e15dd	308	* up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
12028d2d MW	309	* and returns it. @index matches GpioIo/GpioInt resources only so if there
	310	* are total %3 GPIO resources, the index goes from %0 to %2.
	311	*
936e15dd	312	* If the GPIO cannot be translated or there is an error an ERR_PTR is
12028d2d MW	313	* returned.
	314	*
	315	* Note: if the GPIO resource has multiple entries in the pin list, this
	316	* function only returns the first.
	317	*/
936e15dd MW	318	struct gpio_desc acpi_get_gpiod_by_index(struct device dev, int index,
936e15dd MW	319	struct acpi_gpio_info *info)
12028d2d MW	320	{
	321	struct acpi_gpio_lookup lookup;
	322	struct list_head resource_list;
	323	struct acpi_device *adev;
	324	acpi_handle handle;
	325	int ret;
	326
	327	if (!dev)
936e15dd	328	return ERR_PTR(-EINVAL);
12028d2d MW	329
	330	handle = ACPI_HANDLE(dev);
	331	if (!handle \|\| acpi_bus_get_device(handle, &adev))
936e15dd	332	return ERR_PTR(-ENODEV);
12028d2d MW	333
	334	memset(&lookup, 0, sizeof(lookup));
	335	lookup.index = index;
12028d2d MW	336
	337	INIT_LIST_HEAD(&resource_list);
	338	ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio,
	339	&lookup);
	340	if (ret < 0)
936e15dd	341	return ERR_PTR(ret);
12028d2d MW	342
	343	acpi_dev_free_resource_list(&resource_list);
	344
936e15dd	345	if (lookup.desc && info)
12028d2d MW	346	*info = lookup.info;
12028d2d MW	347
a00580c2	348	return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT);
12028d2d	349	}
664e3e5a	350
473ed7be MW	351	static acpi_status
	352	acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
	353	u32 bits, u64 value, void handler_context,
	354	void *region_context)
	355	{
	356	struct acpi_gpio_chip *achip = region_context;
	357	struct gpio_chip *chip = achip->chip;
	358	struct acpi_resource_gpio *agpio;
	359	struct acpi_resource *ares;
	360	acpi_status status;
	361	bool pull_up;
	362	int i;
	363
	364	status = acpi_buffer_to_resource(achip->conn_info.connection,
	365	achip->conn_info.length, &ares);
	366	if (ACPI_FAILURE(status))
	367	return status;
	368
	369	if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) {
	370	ACPI_FREE(ares);
	371	return AE_BAD_PARAMETER;
	372	}
	373
	374	agpio = &ares->data.gpio;
	375	pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP;
	376
	377	if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT &&
	378	function == ACPI_WRITE)) {
	379	ACPI_FREE(ares);
	380	return AE_BAD_PARAMETER;
	381	}
	382
	383	for (i = 0; i < agpio->pin_table_length; i++) {
	384	unsigned pin = agpio->pin_table[i];
	385	struct acpi_gpio_connection *conn;
	386	struct gpio_desc *desc;
	387	bool found;
	388
	389	desc = gpiochip_get_desc(chip, pin);
	390	if (IS_ERR(desc)) {
	391	status = AE_ERROR;
	392	goto out;
	393	}
	394
	395	mutex_lock(&achip->conn_lock);
	396
	397	found = false;
	398	list_for_each_entry(conn, &achip->conns, node) {
	399	if (conn->desc == desc) {
	400	found = true;
	401	break;
	402	}
	403	}
	404	if (!found) {
	405	int ret;
	406
	407	ret = gpiochip_request_own_desc(desc, "ACPI:OpRegion");
	408	if (ret) {
	409	status = AE_ERROR;
	410	mutex_unlock(&achip->conn_lock);
	411	goto out;
	412	}
	413
	414	switch (agpio->io_restriction) {
415	case ACPI_IO_RESTRICT_INPUT:
416	gpiod_direction_input(desc);
417	break;
418	case ACPI_IO_RESTRICT_OUTPUT:
419	/*
420	* ACPI GPIO resources don't contain an
421	* initial value for the GPIO. Therefore we
422	* deduce that value from the pull field
423	* instead. If the pin is pulled up we
424	* assume default to be high, otherwise
425	* low.
426	*/
427	gpiod_direction_output(desc, pull_up);
428	break;
429	default:
430	/*
431	* Assume that the BIOS has configured the
432	* direction and pull accordingly.
433	*/
434	break;
435	}
436
437	conn = kzalloc(sizeof(*conn), GFP_KERNEL);
438	if (!conn) {
439	status = AE_NO_MEMORY;
440	gpiochip_free_own_desc(desc);
441	mutex_unlock(&achip->conn_lock);
442	goto out;
443	}
444
445	conn->desc = desc;
446	list_add_tail(&conn->node, &achip->conns);
447	}
448
449	mutex_unlock(&achip->conn_lock);
450
451	if (function == ACPI_WRITE)
dc62b56a AL	452	gpiod_set_raw_value_cansleep(desc,
dc62b56a AL	453	!!((1 << i) & *value));
473ed7be	454	else
dc62b56a	455	*value \|= (u64)gpiod_get_raw_value_cansleep(desc) << i;
473ed7be MW	456	}
	457
	458	out:
	459	ACPI_FREE(ares);
	460	return status;
	461	}
	462
	463	static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip)
	464	{
	465	struct gpio_chip *chip = achip->chip;
	466	acpi_handle handle = ACPI_HANDLE(chip->dev);
	467	acpi_status status;
	468
	469	INIT_LIST_HEAD(&achip->conns);
	470	mutex_init(&achip->conn_lock);
	471	status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
	472	acpi_gpio_adr_space_handler,
	473	NULL, achip);
	474	if (ACPI_FAILURE(status))
	475	dev_err(chip->dev, "Failed to install GPIO OpRegion handler\n");
	476	}
	477
	478	static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
	479	{
	480	struct gpio_chip *chip = achip->chip;
	481	acpi_handle handle = ACPI_HANDLE(chip->dev);
	482	struct acpi_gpio_connection conn, tmp;
	483	acpi_status status;
	484
	485	status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
	486	acpi_gpio_adr_space_handler);
	487	if (ACPI_FAILURE(status)) {
	488	dev_err(chip->dev, "Failed to remove GPIO OpRegion handler\n");
	489	return;
	490	}
	491
	492	list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) {
	493	gpiochip_free_own_desc(conn->desc);
	494	list_del(&conn->node);
	495	kfree(conn);
	496	}
	497	}
	498
664e3e5a MW	499	void acpi_gpiochip_add(struct gpio_chip *chip)
664e3e5a MW	500	{
aa92b6f6 MW	501	struct acpi_gpio_chip *acpi_gpio;
	502	acpi_handle handle;
	503	acpi_status status;
	504
e9595f84 MW	505	if (!chip \|\| !chip->dev)
	506	return;
	507
aa92b6f6 MW	508	handle = ACPI_HANDLE(chip->dev);
	509	if (!handle)
	510	return;
	511
	512	acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
	513	if (!acpi_gpio) {
	514	dev_err(chip->dev,
	515	"Failed to allocate memory for ACPI GPIO chip\n");
	516	return;
	517	}
	518
	519	acpi_gpio->chip = chip;
	520
	521	status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
	522	if (ACPI_FAILURE(status)) {
	523	dev_err(chip->dev, "Failed to attach ACPI GPIO chip\n");
	524	kfree(acpi_gpio);
	525	return;
	526	}
	527
	528	acpi_gpiochip_request_interrupts(acpi_gpio);
473ed7be	529	acpi_gpiochip_request_regions(acpi_gpio);
664e3e5a MW	530	}
	531
	532	void acpi_gpiochip_remove(struct gpio_chip *chip)
	533	{
aa92b6f6 MW	534	struct acpi_gpio_chip *acpi_gpio;
	535	acpi_handle handle;
	536	acpi_status status;
	537
e9595f84 MW	538	if (!chip \|\| !chip->dev)
	539	return;
	540
aa92b6f6 MW	541	handle = ACPI_HANDLE(chip->dev);
	542	if (!handle)
	543	return;
	544
	545	status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
	546	if (ACPI_FAILURE(status)) {
	547	dev_warn(chip->dev, "Failed to retrieve ACPI GPIO chip\n");
	548	return;
	549	}
	550
473ed7be	551	acpi_gpiochip_free_regions(acpi_gpio);
aa92b6f6 MW	552	acpi_gpiochip_free_interrupts(acpi_gpio);
	553
	554	acpi_detach_data(handle, acpi_gpio_chip_dh);
	555	kfree(acpi_gpio);
664e3e5a	556	}