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

/*
 * ACPI helpers for GPIO API
 *
 * Copyright (C) 2012, Intel Corporation
 * Authors: Mathias Nyman <[email protected]>
 *          Mika Westerberg <[email protected]>
 *
 * 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);
Commit	Line	Data
e29482e8 MN	1	/*
	2	* ACPI helpers for GPIO API
	3	*
	4	* Copyright (C) 2012, Intel Corporation
	5	* Authors: Mathias Nyman <[email protected]>
	6	* Mika Westerberg <[email protected]>
	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/export.h>
	16	#include <linux/acpi_gpio.h>
	17	#include <linux/acpi.h>
0d1c28a4	18	#include <linux/interrupt.h>
e29482e8	19
7fc7acb9 RW	20	struct acpi_gpio_evt_pin {
	21	struct list_head node;
	22	acpi_handle *evt_handle;
	23	unsigned int pin;
	24	unsigned int irq;
	25	};
	26
e29482e8 MN	27	static int acpi_gpiochip_find(struct gpio_chip gc, void data)
	28	{
	29	if (!gc->dev)
	30	return false;
	31
	32	return ACPI_HANDLE(gc->dev) == data;
	33	}
	34
	35	/**
	36	* acpi_get_gpio() - Translate ACPI GPIO pin to GPIO number usable with GPIO API
	37	* @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
	38	* @pin: ACPI GPIO pin number (0-based, controller-relative)
	39	*
	40	* Returns GPIO number to use with Linux generic GPIO API, or errno error value
	41	*/
	42
	43	int acpi_get_gpio(char *path, int pin)
	44	{
	45	struct gpio_chip *chip;
	46	acpi_handle handle;
	47	acpi_status status;
	48
	49	status = acpi_get_handle(NULL, path, &handle);
	50	if (ACPI_FAILURE(status))
	51	return -ENODEV;
	52
	53	chip = gpiochip_find(handle, acpi_gpiochip_find);
	54	if (!chip)
	55	return -ENODEV;
	56
	57	if (!gpio_is_valid(chip->base + pin))
	58	return -EINVAL;
	59
	60	return chip->base + pin;
	61	}
	62	EXPORT_SYMBOL_GPL(acpi_get_gpio);
0d1c28a4	63
0d1c28a4 MN	64	static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
	65	{
	66	acpi_handle handle = data;
	67
	68	acpi_evaluate_object(handle, NULL, NULL, NULL);
	69
	70	return IRQ_HANDLED;
	71	}
	72
7fc7acb9 RW	73	static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
	74	{
	75	struct acpi_gpio_evt_pin *evt_pin = data;
	76	struct acpi_object_list args;
	77	union acpi_object arg;
	78
	79	arg.type = ACPI_TYPE_INTEGER;
	80	arg.integer.value = evt_pin->pin;
	81	args.count = 1;
	82	args.pointer = &arg;
	83
	84	acpi_evaluate_object(evt_pin->evt_handle, NULL, &args, NULL);
	85
	86	return IRQ_HANDLED;
	87	}
	88
	89	static void acpi_gpio_evt_dh(acpi_handle handle, void *data)
	90	{
	91	/* The address of this function is used as a key. */
	92	}
	93
0d1c28a4 MN	94	/**
	95	* acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
	96	* @chip: gpio chip
	97	*
	98	* ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
	99	* handled by ACPI event methods which need to be called from the GPIO
	100	* chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
	101	* gpio pins have acpi event methods and assigns interrupt handlers that calls
	102	* the acpi event methods for those pins.
0d1c28a4	103	*/
0d1c28a4 MN	104	void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
	105	{
	106	struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
	107	struct acpi_resource *res;
7fc7acb9 RW	108	acpi_handle handle, evt_handle;
7fc7acb9 RW	109	struct list_head *evt_pins = NULL;
0d1c28a4	110	acpi_status status;
1107ca10 MN	111	unsigned int pin;
1107ca10 MN	112	int irq, ret;
0d1c28a4 MN	113	char ev_name[5];
	114
	115	if (!chip->dev \|\| !chip->to_irq)
	116	return;
	117
	118	handle = ACPI_HANDLE(chip->dev);
	119	if (!handle)
	120	return;
	121
	122	status = acpi_get_event_resources(handle, &buf);
	123	if (ACPI_FAILURE(status))
	124	return;
	125
7fc7acb9 RW	126	status = acpi_get_handle(handle, "_EVT", &evt_handle);
	127	if (ACPI_SUCCESS(status)) {
	128	evt_pins = kzalloc(sizeof(*evt_pins), GFP_KERNEL);
	129	if (evt_pins) {
	130	INIT_LIST_HEAD(evt_pins);
	131	status = acpi_attach_data(handle, acpi_gpio_evt_dh,
	132	evt_pins);
	133	if (ACPI_FAILURE(status)) {
	134	kfree(evt_pins);
	135	evt_pins = NULL;
	136	}
	137	}
	138	}
0d1c28a4	139
7fc7acb9 RW	140	/*
	141	* If a GPIO interrupt has an ACPI event handler method, or _EVT is
	142	* present, set up an interrupt handler that calls the ACPI event
	143	* handler.
	144	*/
0d1c28a4 MN	145	for (res = buf.pointer;
	146	res && (res->type != ACPI_RESOURCE_TYPE_END_TAG);
	147	res = ACPI_NEXT_RESOURCE(res)) {
7fc7acb9 RW	148	irq_handler_t handler = NULL;
7fc7acb9 RW	149	void *data;
0d1c28a4 MN	150
	151	if (res->type != ACPI_RESOURCE_TYPE_GPIO \|\|
	152	res->data.gpio.connection_type !=
	153	ACPI_RESOURCE_GPIO_TYPE_INT)
	154	continue;
	155
	156	pin = res->data.gpio.pin_table[0];
	157	if (pin > chip->ngpio)
	158	continue;
	159
0d1c28a4 MN	160	irq = chip->to_irq(chip, pin);
	161	if (irq < 0)
	162	continue;
	163
7fc7acb9 RW	164	if (pin <= 255) {
	165	acpi_handle ev_handle;
	166
	167	sprintf(ev_name, "_%c%02X",
	168	res->data.gpio.triggering ? 'E' : 'L', pin);
	169	status = acpi_get_handle(handle, ev_name, &ev_handle);
	170	if (ACPI_SUCCESS(status)) {
	171	handler = acpi_gpio_irq_handler;
	172	data = ev_handle;
	173	}
	174	}
	175	if (!handler && evt_pins) {
	176	struct acpi_gpio_evt_pin *evt_pin;
	177
	178	evt_pin = kzalloc(sizeof(*evt_pin), GFP_KERNEL);
	179	if (!evt_pin)
	180	continue;
	181
	182	list_add_tail(&evt_pin->node, evt_pins);
	183	evt_pin->evt_handle = evt_handle;
	184	evt_pin->pin = pin;
	185	evt_pin->irq = irq;
	186	handler = acpi_gpio_irq_handler_evt;
	187	data = evt_pin;
	188	}
	189	if (!handler)
	190	continue;
	191
0d1c28a4	192	/* Assume BIOS sets the triggering, so no flags */
7fc7acb9 RW	193	ret = devm_request_threaded_irq(chip->dev, irq, NULL, handler,
	194	0, "GPIO-signaled-ACPI-event",
	195	data);
1107ca10 MN	196	if (ret)
	197	dev_err(chip->dev,
	198	"Failed to request IRQ %d ACPI event handler\n",
	199	irq);
0d1c28a4 MN	200	}
	201	}
	202	EXPORT_SYMBOL(acpi_gpiochip_request_interrupts);
7fc7acb9	203
12028d2d MW	204	struct acpi_gpio_lookup {
	205	struct acpi_gpio_info info;
	206	int index;
	207	int gpio;
	208	int n;
	209	};
	210
	211	static int acpi_find_gpio(struct acpi_resource ares, void data)
	212	{
	213	struct acpi_gpio_lookup *lookup = data;
	214
	215	if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
	216	return 1;
	217
	218	if (lookup->n++ == lookup->index && lookup->gpio < 0) {
	219	const struct acpi_resource_gpio *agpio = &ares->data.gpio;
	220
	221	lookup->gpio = acpi_get_gpio(agpio->resource_source.string_ptr,
	222	agpio->pin_table[0]);
	223	lookup->info.gpioint =
	224	agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
	225	}
	226
	227	return 1;
	228	}
	229
	230	/**
	231	* acpi_get_gpio_by_index() - get a GPIO number from device resources
	232	* @dev: pointer to a device to get GPIO from
	233	* @index: index of GpioIo/GpioInt resource (starting from %0)
	234	* @info: info pointer to fill in (optional)
	235	*
	236	* Function goes through ACPI resources for @dev and based on @index looks
	237	* up a GpioIo/GpioInt resource, translates it to the Linux GPIO number,
	238	* and returns it. @index matches GpioIo/GpioInt resources only so if there
	239	* are total %3 GPIO resources, the index goes from %0 to %2.
	240	*
	241	* If the GPIO cannot be translated or there is an error, negative errno is
	242	* returned.
	243	*
	244	* Note: if the GPIO resource has multiple entries in the pin list, this
	245	* function only returns the first.
	246	*/
	247	int acpi_get_gpio_by_index(struct device *dev, int index,
	248	struct acpi_gpio_info *info)
	249	{
	250	struct acpi_gpio_lookup lookup;
	251	struct list_head resource_list;
	252	struct acpi_device *adev;
	253	acpi_handle handle;
	254	int ret;
	255
	256	if (!dev)
	257	return -EINVAL;
	258
	259	handle = ACPI_HANDLE(dev);
	260	if (!handle \|\| acpi_bus_get_device(handle, &adev))
	261	return -ENODEV;
	262
	263	memset(&lookup, 0, sizeof(lookup));
	264	lookup.index = index;
	265	lookup.gpio = -ENODEV;
	266
	267	INIT_LIST_HEAD(&resource_list);
268	ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio,
269	&lookup);
270	if (ret < 0)
271	return ret;
272
273	acpi_dev_free_resource_list(&resource_list);
274
275	if (lookup.gpio >= 0 && info)
276	*info = lookup.info;
277
278	return lookup.gpio;
279	}
280	EXPORT_SYMBOL_GPL(acpi_get_gpio_by_index);
7fc7acb9 RW	281
	282	/**
	283	* acpi_gpiochip_free_interrupts() - Free GPIO _EVT ACPI event interrupts.
	284	* @chip: gpio chip
	285	*
	286	* Free interrupts associated with the _EVT method for the given GPIO chip.
	287	*
	288	* The remaining ACPI event interrupts associated with the chip are freed
	289	* automatically.
	290	*/
	291	void acpi_gpiochip_free_interrupts(struct gpio_chip *chip)
	292	{
	293	acpi_handle handle;
	294	acpi_status status;
	295	struct list_head *evt_pins;
	296	struct acpi_gpio_evt_pin evt_pin, ep;
	297
	298	if (!chip->dev \|\| !chip->to_irq)
	299	return;
	300
	301	handle = ACPI_HANDLE(chip->dev);
	302	if (!handle)
	303	return;
	304
	305	status = acpi_get_data(handle, acpi_gpio_evt_dh, (void **)&evt_pins);
	306	if (ACPI_FAILURE(status))
	307	return;
	308
	309	list_for_each_entry_safe_reverse(evt_pin, ep, evt_pins, node) {
	310	devm_free_irq(chip->dev, evt_pin->irq, evt_pin);
	311	list_del(&evt_pin->node);
	312	kfree(evt_pin);
	313	}
	314
	315	acpi_detach_data(handle, acpi_gpio_evt_dh);
	316	kfree(evt_pins);
	317	}
	318	EXPORT_SYMBOL(acpi_gpiochip_free_interrupts);