mirror of https://gitee.com/openkylin/linux.git
557 lines
13 KiB
C
557 lines
13 KiB
C
/*
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* ACPI helpers for GPIO API
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*
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* Copyright (C) 2012, Intel Corporation
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* Authors: Mathias Nyman <mathias.nyman@linux.intel.com>
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* Mika Westerberg <mika.westerberg@linux.intel.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/errno.h>
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#include <linux/gpio/consumer.h>
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#include <linux/gpio/driver.h>
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#include <linux/export.h>
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#include <linux/acpi.h>
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#include <linux/interrupt.h>
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#include <linux/mutex.h>
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#include "gpiolib.h"
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struct acpi_gpio_event {
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struct list_head node;
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acpi_handle handle;
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unsigned int pin;
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unsigned int irq;
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};
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struct acpi_gpio_connection {
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struct list_head node;
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struct gpio_desc *desc;
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};
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struct acpi_gpio_chip {
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/*
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* ACPICA requires that the first field of the context parameter
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* passed to acpi_install_address_space_handler() is large enough
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* to hold struct acpi_connection_info.
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*/
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struct acpi_connection_info conn_info;
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struct list_head conns;
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struct mutex conn_lock;
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struct gpio_chip *chip;
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struct list_head events;
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};
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static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
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{
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if (!gc->dev)
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return false;
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return ACPI_HANDLE(gc->dev) == data;
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}
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/**
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* acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API
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* @path: ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
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* @pin: ACPI GPIO pin number (0-based, controller-relative)
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*
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* Returns GPIO descriptor to use with Linux generic GPIO API, or ERR_PTR
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* error value
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*/
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static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
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{
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struct gpio_chip *chip;
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acpi_handle handle;
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acpi_status status;
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status = acpi_get_handle(NULL, path, &handle);
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if (ACPI_FAILURE(status))
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return ERR_PTR(-ENODEV);
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chip = gpiochip_find(handle, acpi_gpiochip_find);
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if (!chip)
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return ERR_PTR(-ENODEV);
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if (pin < 0 || pin > chip->ngpio)
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return ERR_PTR(-EINVAL);
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return gpiochip_get_desc(chip, pin);
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}
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static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
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{
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struct acpi_gpio_event *event = data;
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acpi_evaluate_object(event->handle, NULL, NULL, NULL);
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return IRQ_HANDLED;
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}
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static irqreturn_t acpi_gpio_irq_handler_evt(int irq, void *data)
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{
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struct acpi_gpio_event *event = data;
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acpi_execute_simple_method(event->handle, NULL, event->pin);
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return IRQ_HANDLED;
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}
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static void acpi_gpio_chip_dh(acpi_handle handle, void *data)
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{
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/* The address of this function is used as a key. */
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}
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static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
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void *context)
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{
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struct acpi_gpio_chip *acpi_gpio = context;
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struct gpio_chip *chip = acpi_gpio->chip;
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struct acpi_resource_gpio *agpio;
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acpi_handle handle, evt_handle;
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struct acpi_gpio_event *event;
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irq_handler_t handler = NULL;
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struct gpio_desc *desc;
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unsigned long irqflags;
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int ret, pin, irq;
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if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
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return AE_OK;
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agpio = &ares->data.gpio;
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if (agpio->connection_type != ACPI_RESOURCE_GPIO_TYPE_INT)
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return AE_OK;
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handle = ACPI_HANDLE(chip->dev);
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pin = agpio->pin_table[0];
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if (pin <= 255) {
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char ev_name[5];
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sprintf(ev_name, "_%c%02X",
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agpio->triggering == ACPI_EDGE_SENSITIVE ? 'E' : 'L',
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pin);
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if (ACPI_SUCCESS(acpi_get_handle(handle, ev_name, &evt_handle)))
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handler = acpi_gpio_irq_handler;
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}
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if (!handler) {
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if (ACPI_SUCCESS(acpi_get_handle(handle, "_EVT", &evt_handle)))
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handler = acpi_gpio_irq_handler_evt;
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}
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if (!handler)
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return AE_BAD_PARAMETER;
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desc = gpiochip_get_desc(chip, pin);
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if (IS_ERR(desc)) {
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dev_err(chip->dev, "Failed to get GPIO descriptor\n");
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return AE_ERROR;
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}
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ret = gpiochip_request_own_desc(desc, "ACPI:Event");
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if (ret) {
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dev_err(chip->dev, "Failed to request GPIO\n");
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return AE_ERROR;
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}
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gpiod_direction_input(desc);
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ret = gpiod_lock_as_irq(desc);
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if (ret) {
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dev_err(chip->dev, "Failed to lock GPIO as interrupt\n");
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goto fail_free_desc;
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}
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irq = gpiod_to_irq(desc);
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if (irq < 0) {
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dev_err(chip->dev, "Failed to translate GPIO to IRQ\n");
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goto fail_unlock_irq;
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}
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irqflags = IRQF_ONESHOT;
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if (agpio->triggering == ACPI_LEVEL_SENSITIVE) {
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if (agpio->polarity == ACPI_ACTIVE_HIGH)
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irqflags |= IRQF_TRIGGER_HIGH;
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else
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irqflags |= IRQF_TRIGGER_LOW;
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} else {
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switch (agpio->polarity) {
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case ACPI_ACTIVE_HIGH:
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irqflags |= IRQF_TRIGGER_RISING;
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break;
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case ACPI_ACTIVE_LOW:
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irqflags |= IRQF_TRIGGER_FALLING;
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break;
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default:
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irqflags |= IRQF_TRIGGER_RISING |
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IRQF_TRIGGER_FALLING;
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break;
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}
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}
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event = kzalloc(sizeof(*event), GFP_KERNEL);
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if (!event)
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goto fail_unlock_irq;
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event->handle = evt_handle;
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event->irq = irq;
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event->pin = pin;
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ret = request_threaded_irq(event->irq, NULL, handler, irqflags,
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"ACPI:Event", event);
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if (ret) {
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dev_err(chip->dev, "Failed to setup interrupt handler for %d\n",
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event->irq);
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goto fail_free_event;
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}
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list_add_tail(&event->node, &acpi_gpio->events);
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return AE_OK;
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fail_free_event:
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kfree(event);
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fail_unlock_irq:
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gpiod_unlock_as_irq(desc);
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fail_free_desc:
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gpiochip_free_own_desc(desc);
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return AE_ERROR;
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}
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/**
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* acpi_gpiochip_request_interrupts() - Register isr for gpio chip ACPI events
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* @acpi_gpio: ACPI GPIO chip
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*
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* ACPI5 platforms can use GPIO signaled ACPI events. These GPIO interrupts are
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* handled by ACPI event methods which need to be called from the GPIO
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* chip's interrupt handler. acpi_gpiochip_request_interrupts finds out which
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* gpio pins have acpi event methods and assigns interrupt handlers that calls
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* the acpi event methods for those pins.
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*/
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static void acpi_gpiochip_request_interrupts(struct acpi_gpio_chip *acpi_gpio)
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{
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struct gpio_chip *chip = acpi_gpio->chip;
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if (!chip->to_irq)
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return;
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INIT_LIST_HEAD(&acpi_gpio->events);
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acpi_walk_resources(ACPI_HANDLE(chip->dev), "_AEI",
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acpi_gpiochip_request_interrupt, acpi_gpio);
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}
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/**
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* acpi_gpiochip_free_interrupts() - Free GPIO ACPI event interrupts.
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* @acpi_gpio: ACPI GPIO chip
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*
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* Free interrupts associated with GPIO ACPI event method for the given
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* GPIO chip.
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*/
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static void acpi_gpiochip_free_interrupts(struct acpi_gpio_chip *acpi_gpio)
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{
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struct acpi_gpio_event *event, *ep;
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struct gpio_chip *chip = acpi_gpio->chip;
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if (!chip->to_irq)
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return;
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list_for_each_entry_safe_reverse(event, ep, &acpi_gpio->events, node) {
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struct gpio_desc *desc;
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free_irq(event->irq, event);
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desc = gpiochip_get_desc(chip, event->pin);
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if (WARN_ON(IS_ERR(desc)))
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continue;
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gpiod_unlock_as_irq(desc);
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gpiochip_free_own_desc(desc);
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list_del(&event->node);
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kfree(event);
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}
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}
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struct acpi_gpio_lookup {
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struct acpi_gpio_info info;
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int index;
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struct gpio_desc *desc;
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int n;
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};
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static int acpi_find_gpio(struct acpi_resource *ares, void *data)
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{
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struct acpi_gpio_lookup *lookup = data;
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if (ares->type != ACPI_RESOURCE_TYPE_GPIO)
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return 1;
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if (lookup->n++ == lookup->index && !lookup->desc) {
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const struct acpi_resource_gpio *agpio = &ares->data.gpio;
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lookup->desc = acpi_get_gpiod(agpio->resource_source.string_ptr,
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agpio->pin_table[0]);
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lookup->info.gpioint =
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agpio->connection_type == ACPI_RESOURCE_GPIO_TYPE_INT;
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lookup->info.active_low =
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agpio->polarity == ACPI_ACTIVE_LOW;
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}
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return 1;
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}
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/**
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* acpi_get_gpiod_by_index() - get a GPIO descriptor from device resources
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* @dev: pointer to a device to get GPIO from
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* @index: index of GpioIo/GpioInt resource (starting from %0)
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* @info: info pointer to fill in (optional)
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*
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* Function goes through ACPI resources for @dev and based on @index looks
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* up a GpioIo/GpioInt resource, translates it to the Linux GPIO descriptor,
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* and returns it. @index matches GpioIo/GpioInt resources only so if there
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* are total %3 GPIO resources, the index goes from %0 to %2.
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*
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* If the GPIO cannot be translated or there is an error an ERR_PTR is
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* returned.
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*
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* Note: if the GPIO resource has multiple entries in the pin list, this
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* function only returns the first.
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*/
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struct gpio_desc *acpi_get_gpiod_by_index(struct device *dev, int index,
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struct acpi_gpio_info *info)
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{
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struct acpi_gpio_lookup lookup;
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struct list_head resource_list;
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struct acpi_device *adev;
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acpi_handle handle;
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int ret;
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if (!dev)
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return ERR_PTR(-EINVAL);
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handle = ACPI_HANDLE(dev);
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if (!handle || acpi_bus_get_device(handle, &adev))
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return ERR_PTR(-ENODEV);
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memset(&lookup, 0, sizeof(lookup));
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lookup.index = index;
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INIT_LIST_HEAD(&resource_list);
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ret = acpi_dev_get_resources(adev, &resource_list, acpi_find_gpio,
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&lookup);
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if (ret < 0)
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return ERR_PTR(ret);
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acpi_dev_free_resource_list(&resource_list);
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if (lookup.desc && info)
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*info = lookup.info;
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return lookup.desc ? lookup.desc : ERR_PTR(-ENOENT);
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}
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static acpi_status
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acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
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u32 bits, u64 *value, void *handler_context,
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void *region_context)
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{
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struct acpi_gpio_chip *achip = region_context;
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struct gpio_chip *chip = achip->chip;
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struct acpi_resource_gpio *agpio;
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struct acpi_resource *ares;
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acpi_status status;
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bool pull_up;
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int i;
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status = acpi_buffer_to_resource(achip->conn_info.connection,
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achip->conn_info.length, &ares);
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if (ACPI_FAILURE(status))
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return status;
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if (WARN_ON(ares->type != ACPI_RESOURCE_TYPE_GPIO)) {
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ACPI_FREE(ares);
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return AE_BAD_PARAMETER;
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}
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agpio = &ares->data.gpio;
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pull_up = agpio->pin_config == ACPI_PIN_CONFIG_PULLUP;
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if (WARN_ON(agpio->io_restriction == ACPI_IO_RESTRICT_INPUT &&
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function == ACPI_WRITE)) {
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ACPI_FREE(ares);
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return AE_BAD_PARAMETER;
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}
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for (i = 0; i < agpio->pin_table_length; i++) {
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unsigned pin = agpio->pin_table[i];
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struct acpi_gpio_connection *conn;
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struct gpio_desc *desc;
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bool found;
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desc = gpiochip_get_desc(chip, pin);
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if (IS_ERR(desc)) {
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status = AE_ERROR;
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goto out;
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}
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mutex_lock(&achip->conn_lock);
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found = false;
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list_for_each_entry(conn, &achip->conns, node) {
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if (conn->desc == desc) {
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found = true;
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break;
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}
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}
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if (!found) {
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int ret;
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ret = gpiochip_request_own_desc(desc, "ACPI:OpRegion");
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if (ret) {
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status = AE_ERROR;
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mutex_unlock(&achip->conn_lock);
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goto out;
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}
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switch (agpio->io_restriction) {
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case ACPI_IO_RESTRICT_INPUT:
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gpiod_direction_input(desc);
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break;
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case ACPI_IO_RESTRICT_OUTPUT:
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/*
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* ACPI GPIO resources don't contain an
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* initial value for the GPIO. Therefore we
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* deduce that value from the pull field
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* instead. If the pin is pulled up we
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* assume default to be high, otherwise
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* low.
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*/
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gpiod_direction_output(desc, pull_up);
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break;
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default:
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/*
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* Assume that the BIOS has configured the
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* direction and pull accordingly.
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*/
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break;
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}
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conn = kzalloc(sizeof(*conn), GFP_KERNEL);
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if (!conn) {
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status = AE_NO_MEMORY;
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gpiochip_free_own_desc(desc);
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mutex_unlock(&achip->conn_lock);
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goto out;
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}
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conn->desc = desc;
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list_add_tail(&conn->node, &achip->conns);
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}
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mutex_unlock(&achip->conn_lock);
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if (function == ACPI_WRITE)
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gpiod_set_raw_value_cansleep(desc,
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!!((1 << i) & *value));
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else
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*value |= (u64)gpiod_get_raw_value_cansleep(desc) << i;
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}
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out:
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ACPI_FREE(ares);
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return status;
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}
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static void acpi_gpiochip_request_regions(struct acpi_gpio_chip *achip)
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{
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struct gpio_chip *chip = achip->chip;
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acpi_handle handle = ACPI_HANDLE(chip->dev);
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acpi_status status;
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INIT_LIST_HEAD(&achip->conns);
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mutex_init(&achip->conn_lock);
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status = acpi_install_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
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acpi_gpio_adr_space_handler,
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NULL, achip);
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if (ACPI_FAILURE(status))
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dev_err(chip->dev, "Failed to install GPIO OpRegion handler\n");
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}
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static void acpi_gpiochip_free_regions(struct acpi_gpio_chip *achip)
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{
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struct gpio_chip *chip = achip->chip;
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acpi_handle handle = ACPI_HANDLE(chip->dev);
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struct acpi_gpio_connection *conn, *tmp;
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acpi_status status;
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status = acpi_remove_address_space_handler(handle, ACPI_ADR_SPACE_GPIO,
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acpi_gpio_adr_space_handler);
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if (ACPI_FAILURE(status)) {
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dev_err(chip->dev, "Failed to remove GPIO OpRegion handler\n");
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return;
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}
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list_for_each_entry_safe_reverse(conn, tmp, &achip->conns, node) {
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gpiochip_free_own_desc(conn->desc);
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list_del(&conn->node);
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kfree(conn);
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}
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}
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void acpi_gpiochip_add(struct gpio_chip *chip)
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{
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struct acpi_gpio_chip *acpi_gpio;
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acpi_handle handle;
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acpi_status status;
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if (!chip || !chip->dev)
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return;
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handle = ACPI_HANDLE(chip->dev);
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if (!handle)
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return;
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acpi_gpio = kzalloc(sizeof(*acpi_gpio), GFP_KERNEL);
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if (!acpi_gpio) {
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dev_err(chip->dev,
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"Failed to allocate memory for ACPI GPIO chip\n");
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return;
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}
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acpi_gpio->chip = chip;
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status = acpi_attach_data(handle, acpi_gpio_chip_dh, acpi_gpio);
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if (ACPI_FAILURE(status)) {
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dev_err(chip->dev, "Failed to attach ACPI GPIO chip\n");
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kfree(acpi_gpio);
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return;
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}
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acpi_gpiochip_request_interrupts(acpi_gpio);
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acpi_gpiochip_request_regions(acpi_gpio);
|
|
}
|
|
|
|
void acpi_gpiochip_remove(struct gpio_chip *chip)
|
|
{
|
|
struct acpi_gpio_chip *acpi_gpio;
|
|
acpi_handle handle;
|
|
acpi_status status;
|
|
|
|
if (!chip || !chip->dev)
|
|
return;
|
|
|
|
handle = ACPI_HANDLE(chip->dev);
|
|
if (!handle)
|
|
return;
|
|
|
|
status = acpi_get_data(handle, acpi_gpio_chip_dh, (void **)&acpi_gpio);
|
|
if (ACPI_FAILURE(status)) {
|
|
dev_warn(chip->dev, "Failed to retrieve ACPI GPIO chip\n");
|
|
return;
|
|
}
|
|
|
|
acpi_gpiochip_free_regions(acpi_gpio);
|
|
acpi_gpiochip_free_interrupts(acpi_gpio);
|
|
|
|
acpi_detach_data(handle, acpi_gpio_chip_dh);
|
|
kfree(acpi_gpio);
|
|
}
|