drivers/gpio/gpiolib-acpi.c - kernel/msm-4.9 - Gitiles

 /*
  * 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.h>
 #include <linux/export.h>
 #include <linux/acpi_gpio.h>
 #include <linux/acpi.h>
 #include <linux/interrupt.h>

 struct acpi_gpio_evt_pin {
 	struct list_head node;
 	acpi_handle *evt_handle;
 	unsigned int pin;
 	unsigned int irq;
 };

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

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

 /**
  * acpi_get_gpio() - Translate ACPI GPIO pin to GPIO number 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 number to use with Linux generic GPIO API, or errno error value
  */

 int acpi_get_gpio(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 -ENODEV;

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

 	if (!gpio_is_valid(chip->base + pin))
 		return -EINVAL;

 	return chip->base + pin;
 }
 EXPORT_SYMBOL_GPL(acpi_get_gpio);

 static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
 {
 	acpi_handle handle = data;

 	acpi_evaluate_object(handle, NULL, NULL, NULL);

 	return IRQ_HANDLED;
 }

 static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
 {
 	struct acpi_gpio_evt_pin *evt_pin = data;
 	struct acpi_object_list args;
 	union acpi_object arg;

 	arg.type = ACPI_TYPE_INTEGER;
 	arg.integer.value = evt_pin->pin;
 	args.count = 1;
 	args.pointer = &arg;

 	acpi_evaluate_object(evt_pin->evt_handle, NULL, &args, NULL);

 	return IRQ_HANDLED;
 }

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

 /**
  * acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
  * @chip:      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.
  */
 void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
 {
 	struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
 	struct acpi_resource *res;
 	acpi_handle handle, evt_handle;
 	struct list_head *evt_pins = NULL;
 	acpi_status status;
 	unsigned int pin;
 	int irq, ret;
 	char ev_name[5];

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

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

 	status = acpi_get_event_resources(handle, &buf);
 	if (ACPI_FAILURE(status))
 		return;

 	status = acpi_get_handle(handle, "_EVT", &evt_handle);
 	if (ACPI_SUCCESS(status)) {
 		evt_pins = kzalloc(sizeof(*evt_pins), GFP_KERNEL);
 		if (evt_pins) {
 			INIT_LIST_HEAD(evt_pins);
 			status = acpi_attach_data(handle, acpi_gpio_evt_dh,
 						  evt_pins);
 			if (ACPI_FAILURE(status)) {
 				kfree(evt_pins);
 				evt_pins = NULL;
 			}
 		}
 	}

 	/*
 	 * If a GPIO interrupt has an ACPI event handler method, or _EVT is
 	 * present, set up an interrupt handler that calls the ACPI event
 	 * handler.
 	 */
 	for (res = buf.pointer;
 	     res && (res->type != ACPI_RESOURCE_TYPE_END_TAG);
 	     res = ACPI_NEXT_RESOURCE(res)) {
 		irq_handler_t handler = NULL;
 		void *data;

 		if (res->type != ACPI_RESOURCE_TYPE_GPIO ||
 		    res->data.gpio.connection_type !=
 		    ACPI_RESOURCE_GPIO_TYPE_INT)
 			continue;

 		pin = res->data.gpio.pin_table[0];
 		if (pin > chip->ngpio)
 			continue;

 		irq = chip->to_irq(chip, pin);
 		if (irq < 0)
 			continue;

 		if (pin <= 255) {
 			acpi_handle ev_handle;

 			sprintf(ev_name, "_%c%02X",
 				res->data.gpio.triggering ? 'E' : 'L', pin);
 			status = acpi_get_handle(handle, ev_name, &ev_handle);
 			if (ACPI_SUCCESS(status)) {
 				handler = acpi_gpio_irq_handler;
 				data = ev_handle;
 			}
 		}
 		if (!handler && evt_pins) {
 			struct acpi_gpio_evt_pin *evt_pin;

 			evt_pin = kzalloc(sizeof(*evt_pin), GFP_KERNEL);
 			if (!evt_pin)
 				continue;

 			list_add_tail(&evt_pin->node, evt_pins);
 			evt_pin->evt_handle = evt_handle;
 			evt_pin->pin = pin;
 			evt_pin->irq = irq;
 			handler = acpi_gpio_irq_handler_evt;
 			data = evt_pin;
 		}
 		if (!handler)
 			continue;

 		/* Assume BIOS sets the triggering, so no flags */
 		ret = devm_request_threaded_irq(chip->dev, irq, NULL, handler,
 						0, "GPIO-signaled-ACPI-event",
 						data);
 		if (ret)
 			dev_err(chip->dev,
 				"Failed to request IRQ %d ACPI event handler\n",
 				irq);
 	}
 }
 EXPORT_SYMBOL(acpi_gpiochip_request_interrupts);

 struct acpi_gpio_lookup {
 	struct acpi_gpio_info info;
 	int index;
 	int gpio;
 	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->gpio < 0) {
 		const struct acpi_resource_gpio *agpio = &ares->data.gpio;

 		lookup->gpio = acpi_get_gpio(agpio->resource_source.string_ptr,
 					     agpio->pin_table[0]);
 		lookup->info.gpioint =
 			agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
 	}

 	return 1;
 }

 /**
  * acpi_get_gpio_by_index() - get a GPIO number 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 number,
  * 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, negative errno is
  * returned.
  *
  * Note: if the GPIO resource has multiple entries in the pin list, this
  * function only returns the first.
  */
 int acpi_get_gpio_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 -EINVAL;

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

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

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

 	acpi_dev_free_resource_list(&resource_list);

 	if (lookup.gpio >= 0 && info)
 		*info = lookup.info;

 	return lookup.gpio;
 }
 EXPORT_SYMBOL_GPL(acpi_get_gpio_by_index);

 /**
  * acpi_gpiochip_free_interrupts() - Free GPIO _EVT ACPI event interrupts.
  * @chip:      gpio chip
  *
  * Free interrupts associated with the _EVT method for the given GPIO chip.
  *
  * The remaining ACPI event interrupts associated with the chip are freed
  * automatically.
  */
 void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
 {
 	acpi_handle handle;
 	acpi_status status;
 	struct list_head *evt_pins;
 	struct acpi_gpio_evt_pin *evt_pin, *ep;

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

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

 	status = acpi_get_data(handle, acpi_gpio_evt_dh, (void **)&evt_pins);
 	if (ACPI_FAILURE(status))
 		return;

 	list_for_each_entry_safe_reverse(evt_pin, ep, evt_pins, node) {
 		devm_free_irq(chip->dev, evt_pin->irq, evt_pin);
 		list_del(&evt_pin->node);
 		kfree(evt_pin);
 	}

 	acpi_detach_data(handle, acpi_gpio_evt_dh);
 	kfree(evt_pins);
 }
 EXPORT_SYMBOL(acpi_gpiochip_free_interrupts);
	/*
	* 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.h>
	#include <linux/export.h>
	#include <linux/acpi_gpio.h>
	#include <linux/acpi.h>
	#include <linux/interrupt.h>

	struct acpi_gpio_evt_pin {
	struct list_head node;
	acpi_handle *evt_handle;
	unsigned int pin;
	unsigned int irq;
	};

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

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

	/**
	* acpi_get_gpio() - Translate ACPI GPIO pin to GPIO number 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 number to use with Linux generic GPIO API, or errno error value
	*/

	int acpi_get_gpio(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 -ENODEV;

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

	if (!gpio_is_valid(chip->base + pin))
	return -EINVAL;

	return chip->base + pin;
	}
	EXPORT_SYMBOL_GPL(acpi_get_gpio);

	static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
	{
	acpi_handle handle = data;

	acpi_evaluate_object(handle, NULL, NULL, NULL);

	return IRQ_HANDLED;
	}

	static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
	{
	struct acpi_gpio_evt_pin *evt_pin = data;
	struct acpi_object_list args;
	union acpi_object arg;

	arg.type = ACPI_TYPE_INTEGER;
	arg.integer.value = evt_pin->pin;
	args.count = 1;
	args.pointer = &arg;

	acpi_evaluate_object(evt_pin->evt_handle, NULL, &args, NULL);

	return IRQ_HANDLED;
	}

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

	/**
	* acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
	* @chip: 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.
	*/
	void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
	{
	struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
	struct acpi_resource *res;
	acpi_handle handle, evt_handle;
	struct list_head *evt_pins = NULL;
	acpi_status status;
	unsigned int pin;
	int irq, ret;
	char ev_name[5];

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

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

	status = acpi_get_event_resources(handle, &buf);
	if (ACPI_FAILURE(status))
	return;

	status = acpi_get_handle(handle, "_EVT", &evt_handle);
	if (ACPI_SUCCESS(status)) {
	evt_pins = kzalloc(sizeof(*evt_pins), GFP_KERNEL);
	if (evt_pins) {
	INIT_LIST_HEAD(evt_pins);
	status = acpi_attach_data(handle, acpi_gpio_evt_dh,
	evt_pins);
	if (ACPI_FAILURE(status)) {
	kfree(evt_pins);
	evt_pins = NULL;
	}
	}
	}

	/*
	* If a GPIO interrupt has an ACPI event handler method, or _EVT is
	* present, set up an interrupt handler that calls the ACPI event
	* handler.
	*/
	for (res = buf.pointer;
	res && (res->type != ACPI_RESOURCE_TYPE_END_TAG);
	res = ACPI_NEXT_RESOURCE(res)) {
	irq_handler_t handler = NULL;
	void *data;

	if (res->type != ACPI_RESOURCE_TYPE_GPIO \|\|
	res->data.gpio.connection_type !=
	ACPI_RESOURCE_GPIO_TYPE_INT)
	continue;

	pin = res->data.gpio.pin_table[0];
	if (pin > chip->ngpio)
	continue;

	irq = chip->to_irq(chip, pin);
	if (irq < 0)
	continue;

	if (pin <= 255) {
	acpi_handle ev_handle;

	sprintf(ev_name, "_%c%02X",
	res->data.gpio.triggering ? 'E' : 'L', pin);
	status = acpi_get_handle(handle, ev_name, &ev_handle);
	if (ACPI_SUCCESS(status)) {
	handler = acpi_gpio_irq_handler;
	data = ev_handle;
	}
	}
	if (!handler && evt_pins) {
	struct acpi_gpio_evt_pin *evt_pin;

	evt_pin = kzalloc(sizeof(*evt_pin), GFP_KERNEL);
	if (!evt_pin)
	continue;

	list_add_tail(&evt_pin->node, evt_pins);
	evt_pin->evt_handle = evt_handle;
	evt_pin->pin = pin;
	evt_pin->irq = irq;
	handler = acpi_gpio_irq_handler_evt;
	data = evt_pin;
	}
	if (!handler)
	continue;

	/* Assume BIOS sets the triggering, so no flags */
	ret = devm_request_threaded_irq(chip->dev, irq, NULL, handler,
	0, "GPIO-signaled-ACPI-event",
	data);
	if (ret)
	dev_err(chip->dev,
	"Failed to request IRQ %d ACPI event handler\n",
	irq);
	}
	}
	EXPORT_SYMBOL(acpi_gpiochip_request_interrupts);

	struct acpi_gpio_lookup {
	struct acpi_gpio_info info;
	int index;
	int gpio;
	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->gpio < 0) {
	const struct acpi_resource_gpio *agpio = &ares->data.gpio;

	lookup->gpio = acpi_get_gpio(agpio->resource_source.string_ptr,
	agpio->pin_table[0]);
	lookup->info.gpioint =
	agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
	}

	return 1;
	}

	/**
	* acpi_get_gpio_by_index() - get a GPIO number 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 number,
	* 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, negative errno is
	* returned.
	*
	* Note: if the GPIO resource has multiple entries in the pin list, this
	* function only returns the first.
	*/
	int acpi_get_gpio_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 -EINVAL;

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

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

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

	acpi_dev_free_resource_list(&resource_list);

	if (lookup.gpio >= 0 && info)
	*info = lookup.info;

	return lookup.gpio;
	}
	EXPORT_SYMBOL_GPL(acpi_get_gpio_by_index);

	/**
	* acpi_gpiochip_free_interrupts() - Free GPIO _EVT ACPI event interrupts.
	* @chip: gpio chip
	*
	* Free interrupts associated with the _EVT method for the given GPIO chip.
	*
	* The remaining ACPI event interrupts associated with the chip are freed
	* automatically.
	*/
	void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
	{
	acpi_handle handle;
	acpi_status status;
	struct list_head *evt_pins;
	struct acpi_gpio_evt_pin evt_pin, ep;

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

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

	status = acpi_get_data(handle, acpi_gpio_evt_dh, (void **)&evt_pins);
	if (ACPI_FAILURE(status))
	return;

	list_for_each_entry_safe_reverse(evt_pin, ep, evt_pins, node) {
	devm_free_irq(chip->dev, evt_pin->irq, evt_pin);
	list_del(&evt_pin->node);
	kfree(evt_pin);
	}

	acpi_detach_data(handle, acpi_gpio_evt_dh);
	kfree(evt_pins);
	}
	EXPORT_SYMBOL(acpi_gpiochip_free_interrupts);