Quelle  tiny-power-button.c   Sprache: C

// SPDX-License-Identifier: GPL-2.0-or-later
#include <linux/module.h>
#include <linux/sched/signal.h>
#include <linux/acpi.h>
#include <acpi/button.h>

MODULE_AUTHOR("Josh Triplett");
MODULE_DESCRIPTION("ACPI Tiny Power Button Driver");
MODULE_LICENSE("GPL");

static int power_signal __read_mostly = CONFIG_ACPI_TINY_POWER_BUTTON_SIGNAL;
module_param(power_signal, int, 0644);
MODULE_PARM_DESC(power_signal, "Power button sends this signal to init");

static const struct acpi_device_id tiny_power_button_device_ids[] = {
 { ACPI_BUTTON_HID_POWER, 0 },
 { ACPI_BUTTON_HID_POWERF, 0 },
 { "", 0 },
};
MODULE_DEVICE_TABLE(acpi, tiny_power_button_device_ids);

static void acpi_tiny_power_button_notify(acpi_handle handle, u32 event, void *data)
{
 kill_cad_pid(power_signal, 1);
}

static void acpi_tiny_power_button_notify_run(void *not_used)
{
 acpi_tiny_power_button_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, NULL);
}

static u32 acpi_tiny_power_button_event(void *not_used)
{
 acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_tiny_power_button_notify_run, NULL);
 return ACPI_INTERRUPT_HANDLED;
}

static int acpi_tiny_power_button_add(struct acpi_device *device)
{
 acpi_status status;

 if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON) {
  status = acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
         acpi_tiny_power_button_event,
         NULL);
 } else {
  status = acpi_install_notify_handler(device->handle,
           ACPI_DEVICE_NOTIFY,
           acpi_tiny_power_button_notify,
           NULL);
 }
 if (ACPI_FAILURE(status))
  return -ENODEV;

 return 0;
}

static void acpi_tiny_power_button_remove(struct acpi_device *device)
{
 if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON) {
  acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
      acpi_tiny_power_button_event);
 } else {
  acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
        acpi_tiny_power_button_notify);
 }
 acpi_os_wait_events_complete();
}

static struct acpi_driver acpi_tiny_power_button_driver = {
 .name = "tiny-power-button",
 .class = "tiny-power-button",
 .ids = tiny_power_button_device_ids,
 .ops = {
  .add = acpi_tiny_power_button_add,
  .remove = acpi_tiny_power_button_remove,
 },
};

module_acpi_driver(acpi_tiny_power_button_driver);