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

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;
}

/**
 * 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.
 *
 * Interrupts are automatically freed on driver detach
 */

void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
{
	struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
	struct acpi_resource *res;
	acpi_handle handle, ev_handle;
	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;

	/* If a gpio interrupt has an acpi event handler method, then
	 * 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)) {

		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;

		sprintf(ev_name, "_%c%02X",
		res->data.gpio.triggering ? 'E' : 'L', pin);

		status = acpi_get_handle(handle, ev_name, &ev_handle);
		if (ACPI_FAILURE(status))
			continue;

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

		/* Assume BIOS sets the triggering, so no flags */
		ret = devm_request_threaded_irq(chip->dev, irq, NULL,
					  acpi_gpio_irq_handler,
					  0,
					  "GPIO-signaled-ACPI-event",
					  ev_handle);
		if (ret)
			dev_err(chip->dev,
				"Failed to request IRQ %d ACPI event handler\n",
				irq);
	}
}
EXPORT_SYMBOL(acpi_gpiochip_request_interrupts);
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>
	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 MN	19
	20	static int acpi_gpiochip_find(struct gpio_chip gc, void data)
	21	{
	22	if (!gc->dev)
	23	return false;
	24
	25	return ACPI_HANDLE(gc->dev) == data;
	26	}
	27
	28	/**
	29	* acpi_get_gpio() - Translate ACPI GPIO pin to GPIO number usable with GPIO API
	30	* @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
	31	* @pin: ACPI GPIO pin number (0-based, controller-relative)
	32	*
	33	* Returns GPIO number to use with Linux generic GPIO API, or errno error value
	34	*/
	35
	36	int acpi_get_gpio(char *path, int pin)
	37	{
	38	struct gpio_chip *chip;
	39	acpi_handle handle;
	40	acpi_status status;
	41
	42	status = acpi_get_handle(NULL, path, &handle);
	43	if (ACPI_FAILURE(status))
	44	return -ENODEV;
	45
	46	chip = gpiochip_find(handle, acpi_gpiochip_find);
	47	if (!chip)
	48	return -ENODEV;
	49
	50	if (!gpio_is_valid(chip->base + pin))
	51	return -EINVAL;
	52
	53	return chip->base + pin;
	54	}
	55	EXPORT_SYMBOL_GPL(acpi_get_gpio);
0d1c28a4 MN	56
	57
	58	static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
	59	{
	60	acpi_handle handle = data;
	61
	62	acpi_evaluate_object(handle, NULL, NULL, NULL);
	63
	64	return IRQ_HANDLED;
	65	}
	66
	67	/**
	68	* acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
	69	* @chip: gpio chip
	70	*
	71	* ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
	72	* handled by ACPI event methods which need to be called from the GPIO
	73	* chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
	74	* gpio pins have acpi event methods and assigns interrupt handlers that calls
	75	* the acpi event methods for those pins.
	76	*
	77	* Interrupts are automatically freed on driver detach
	78	*/
	79
	80	void acpi_gpiochip_request_interrupts(struct gpio_chip *chip)
	81	{
	82	struct acpi_buffer buf = {ACPI_ALLOCATE_BUFFER, NULL};
	83	struct acpi_resource *res;
	84	acpi_handle handle, ev_handle;
	85	acpi_status status;
1107ca10 MN	86	unsigned int pin;
1107ca10 MN	87	int irq, ret;
0d1c28a4 MN	88	char ev_name[5];
	89
	90	if (!chip->dev \|\| !chip->to_irq)
	91	return;
	92
	93	handle = ACPI_HANDLE(chip->dev);
	94	if (!handle)
	95	return;
	96
	97	status = acpi_get_event_resources(handle, &buf);
	98	if (ACPI_FAILURE(status))
	99	return;
	100
	101	/* If a gpio interrupt has an acpi event handler method, then
	102	* set up an interrupt handler that calls the acpi event handler
	103	*/
	104
	105	for (res = buf.pointer;
	106	res && (res->type != ACPI_RESOURCE_TYPE_END_TAG);
	107	res = ACPI_NEXT_RESOURCE(res)) {
	108
	109	if (res->type != ACPI_RESOURCE_TYPE_GPIO \|\|
	110	res->data.gpio.connection_type !=
	111	ACPI_RESOURCE_GPIO_TYPE_INT)
	112	continue;
	113
	114	pin = res->data.gpio.pin_table[0];
	115	if (pin > chip->ngpio)
	116	continue;
	117
	118	sprintf(ev_name, "_%c%02X",
	119	res->data.gpio.triggering ? 'E' : 'L', pin);
	120
	121	status = acpi_get_handle(handle, ev_name, &ev_handle);
	122	if (ACPI_FAILURE(status))
	123	continue;
	124
	125	irq = chip->to_irq(chip, pin);
	126	if (irq < 0)
	127	continue;
	128
	129	/* Assume BIOS sets the triggering, so no flags */
1107ca10	130	ret = devm_request_threaded_irq(chip->dev, irq, NULL,
0d1c28a4 MN	131	acpi_gpio_irq_handler,
	132	0,
	133	"GPIO-signaled-ACPI-event",
	134	ev_handle);
1107ca10 MN	135	if (ret)
	136	dev_err(chip->dev,
	137	"Failed to request IRQ %d ACPI event handler\n",
	138	irq);
0d1c28a4 MN	139	}
	140	}
	141	EXPORT_SYMBOL(acpi_gpiochip_request_interrupts);