swh:1:snp:49cd9498d6cccc5e78252c27dcb645bcf7bf0c91
Tip revision: f75aef392f869018f78cfedf3c320a6b3fcfda6b authored by Linus Torvalds on 30 August 2020, 23:01:54 UTC
Linux 5.9-rc3
Linux 5.9-rc3
Tip revision: f75aef3
wakeup.c
// SPDX-License-Identifier: GPL-2.0
/*
* wakeup.c - support wakeup devices
* Copyright (C) 2004 Li Shaohua <shaohua.li@intel.com>
*/
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include "internal.h"
#include "sleep.h"
struct acpi_wakeup_handler {
struct list_head list_node;
bool (*wakeup)(void *context);
void *context;
};
static LIST_HEAD(acpi_wakeup_handler_head);
static DEFINE_MUTEX(acpi_wakeup_handler_mutex);
/*
* We didn't lock acpi_device_lock in the file, because it invokes oops in
* suspend/resume and isn't really required as this is called in S-state. At
* that time, there is no device hotplug
**/
#define _COMPONENT ACPI_SYSTEM_COMPONENT
ACPI_MODULE_NAME("wakeup_devices")
/**
* acpi_enable_wakeup_devices - Enable wake-up device GPEs.
* @sleep_state: ACPI system sleep state.
*
* Enable wakeup device power of devices with the state.enable flag set and set
* the wakeup enable mask bits in the GPE registers that correspond to wakeup
* devices.
*/
void acpi_enable_wakeup_devices(u8 sleep_state)
{
struct acpi_device *dev, *tmp;
list_for_each_entry_safe(dev, tmp, &acpi_wakeup_device_list,
wakeup_list) {
if (!dev->wakeup.flags.valid
|| sleep_state > (u32) dev->wakeup.sleep_state
|| !(device_may_wakeup(&dev->dev)
|| dev->wakeup.prepare_count))
continue;
if (device_may_wakeup(&dev->dev))
acpi_enable_wakeup_device_power(dev, sleep_state);
/* The wake-up power should have been enabled already. */
acpi_set_gpe_wake_mask(dev->wakeup.gpe_device, dev->wakeup.gpe_number,
ACPI_GPE_ENABLE);
}
}
/**
* acpi_disable_wakeup_devices - Disable devices' wakeup capability.
* @sleep_state: ACPI system sleep state.
*/
void acpi_disable_wakeup_devices(u8 sleep_state)
{
struct acpi_device *dev, *tmp;
list_for_each_entry_safe(dev, tmp, &acpi_wakeup_device_list,
wakeup_list) {
if (!dev->wakeup.flags.valid
|| sleep_state > (u32) dev->wakeup.sleep_state
|| !(device_may_wakeup(&dev->dev)
|| dev->wakeup.prepare_count))
continue;
acpi_set_gpe_wake_mask(dev->wakeup.gpe_device, dev->wakeup.gpe_number,
ACPI_GPE_DISABLE);
if (device_may_wakeup(&dev->dev))
acpi_disable_wakeup_device_power(dev);
}
}
int __init acpi_wakeup_device_init(void)
{
struct acpi_device *dev, *tmp;
mutex_lock(&acpi_device_lock);
list_for_each_entry_safe(dev, tmp, &acpi_wakeup_device_list,
wakeup_list) {
if (device_can_wakeup(&dev->dev)) {
/* Button GPEs are supposed to be always enabled. */
acpi_enable_gpe(dev->wakeup.gpe_device,
dev->wakeup.gpe_number);
device_set_wakeup_enable(&dev->dev, true);
}
}
mutex_unlock(&acpi_device_lock);
return 0;
}
/**
* acpi_register_wakeup_handler - Register wakeup handler
* @wake_irq: The IRQ through which the device may receive wakeups
* @wakeup: Wakeup-handler to call when the SCI has triggered a wakeup
* @context: Context to pass to the handler when calling it
*
* Drivers which may share an IRQ with the SCI can use this to register
* a handler which returns true when the device they are managing wants
* to trigger a wakeup.
*/
int acpi_register_wakeup_handler(int wake_irq, bool (*wakeup)(void *context),
void *context)
{
struct acpi_wakeup_handler *handler;
/*
* If the device is not sharing its IRQ with the SCI, there is no
* need to register the handler.
*/
if (!acpi_sci_irq_valid() || wake_irq != acpi_sci_irq)
return 0;
handler = kmalloc(sizeof(*handler), GFP_KERNEL);
if (!handler)
return -ENOMEM;
handler->wakeup = wakeup;
handler->context = context;
mutex_lock(&acpi_wakeup_handler_mutex);
list_add(&handler->list_node, &acpi_wakeup_handler_head);
mutex_unlock(&acpi_wakeup_handler_mutex);
return 0;
}
EXPORT_SYMBOL_GPL(acpi_register_wakeup_handler);
/**
* acpi_unregister_wakeup_handler - Unregister wakeup handler
* @wakeup: Wakeup-handler passed to acpi_register_wakeup_handler()
* @context: Context passed to acpi_register_wakeup_handler()
*/
void acpi_unregister_wakeup_handler(bool (*wakeup)(void *context),
void *context)
{
struct acpi_wakeup_handler *handler;
mutex_lock(&acpi_wakeup_handler_mutex);
list_for_each_entry(handler, &acpi_wakeup_handler_head, list_node) {
if (handler->wakeup == wakeup && handler->context == context) {
list_del(&handler->list_node);
kfree(handler);
break;
}
}
mutex_unlock(&acpi_wakeup_handler_mutex);
}
EXPORT_SYMBOL_GPL(acpi_unregister_wakeup_handler);
bool acpi_check_wakeup_handlers(void)
{
struct acpi_wakeup_handler *handler;
/* No need to lock, nothing else is running when we're called. */
list_for_each_entry(handler, &acpi_wakeup_handler_head, list_node) {
if (handler->wakeup(handler->context))
return true;
}
return false;
}