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_acpi_driver(acpi_tiny_power_button_driver); 44