/*
* 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/gpio/consumer.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/machine.h>
#include <linux/export.h>
#include <linux/acpi.h>
#include <linux/interrupt.h>
#include <linux/mutex.h>
#include <linux/pinctrl/pinctrl.h>
#include "gpiolib.h"
struct acpi_gpio_event {
struct list_head node;
acpi_handle handle;
unsigned int pin;
unsigned int irq;
struct gpio_desc *desc;
};
struct acpi_gpio_connection {
struct list_head node;
unsigned int pin;
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->parent)
return false;
return ACPI_HANDLE(gc->parent) == 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)
*
* Return: GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR
* error value. Specifically returns %-EPROBE_DEFER if the referenced GPIO
* controller does not have gpiochip registered at the moment. This is to
* support probe deferral.
*/
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(-EPROBE_DEFER);
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. */
}
bool acpi_gpio_get_irq_resource(struct acpi_resource *ares,
struct acpi_resource_gpio **agpio)
{
struct acpi_resource_gpio *gpio;
if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
return false;
gpio = &ares->data.gpio;
if (gpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT)
return false;
*agpio = gpio;
return true;
}
EXPORT_SYMBOL_GPL(acpi_gpio_get_irq_resource);
static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
void *context)
{
struct acpi_gpio_chip *acpi_gpio = context;
struct