// SPDX-License-Identifier: GPL-2.0
/*
* 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>
*/
#include <linux/errno.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 - ACPI GPIO event handler data
*
* @node: list-entry of the events list of the struct acpi_gpio_chip
* @handle: handle of ACPI method to execute when the IRQ triggers
* @handler: handler function to pass to request_irq() when requesting the IRQ
* @pin: GPIO pin number on the struct gpio_chip
* @irq: Linux IRQ number for the event, for request_irq() / free_irq()
* @irqflags: flags to pass to request_irq() when requesting the IRQ
* @irq_is_wake: If the ACPI flags indicate the IRQ is a wakeup source
* @irq_requested:True if request_irq() has been done
* @desc: struct gpio_desc for the GPIO pin for this event
*/
struct acpi_gpio_event {
struct list_head node;
acpi_handle handle;
irq_handler_t handler;
unsigned int pin;
unsigned int irq;
unsigned long irqflags;
bool irq_is_wake;
bool irq_requested;
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;
struct list_head deferred_req_irqs_list_entry;
};
/*
* For GPIO chips which call acpi_gpiochip_request_interrupts() before late_init
* (so builtin drivers) we register the ACPI GpioInt IRQ handlers from a
* late_initcall_sync() handler, so that other builtin drivers can register their
* OpRegions before the event handlers can run. This list contains GPIO chips
* for which the acpi_gpiochip_request_irqs() call has been deferred.
*/
static DEFINE_MUTEX(acpi_gpio_deferred_req_irqs_lock);
static LIST_HEAD(acpi_gpio_deferred_req_irqs_list);
static bool acpi_gpio_deferred_req_irqs_done;
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 GPIO chip 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,