drivers/acpi/tiny-power-button.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 #include <linux/module.h>
   3 #include <linux/sched/signal.h>
   4 #include <linux/acpi.h>
   5 #include <acpi/button.h>
   6
   7 MODULE_AUTHOR("Josh Triplett");
   8 MODULE_DESCRIPTION("ACPI Tiny Power Button Driver");
   9 MODULE_LICENSE("GPL");
  10
  11 static int power_signal __read_mostly = CONFIG_ACPI_TINY_POWER_BUTTON_SIGNAL;
  12 module_param(power_signal, int, 0644);
  13 MODULE_PARM_DESC(power_signal, "Power button sends this signal to init");
  14
  15 static const struct acpi_device_id tiny_power_button_device_ids[] = {
  16         { ACPI_BUTTON_HID_POWER, 0 },
  17         { ACPI_BUTTON_HID_POWERF, 0 },
  18         { "", 0 },
  19 };
  20 MODULE_DEVICE_TABLE(acpi, tiny_power_button_device_ids);
  21
  22 static int acpi_noop_add_remove(struct acpi_device *device)
  23 {
  24         return 0;
  25 }
  26
  27 static void acpi_tiny_power_button_notify(struct acpi_device *device, u32 event)
  28 {
  29         kill_cad_pid(power_signal, 1);
  30 }
  31
  32 static struct acpi_driver acpi_tiny_power_button_driver = {
  33         .name = "tiny-power-button",
  34         .class = "tiny-power-button",
  35         .ids = tiny_power_button_device_ids,
  36         .ops = {
  37                 .add = acpi_noop_add_remove,
  38                 .remove = acpi_noop_add_remove,
  39                 .notify = acpi_tiny_power_button_notify,
  40         },
  41 };
  42
  43 module_driver(acpi_tiny_power_button_driver,
  44                 acpi_bus_register_driver,
  45                 acpi_bus_unregister_driver);