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1// SPDX-License-Identifier: GPL-2.0-or-later2#include <linux/module.h>3#include <linux/sched/signal.h>4#include <linux/acpi.h>5#include <acpi/button.h>6 7MODULE_AUTHOR("Josh Triplett");8MODULE_DESCRIPTION("ACPI Tiny Power Button Driver");9MODULE_LICENSE("GPL");10 11static int power_signal __read_mostly = CONFIG_ACPI_TINY_POWER_BUTTON_SIGNAL;12module_param(power_signal, int, 0644);13MODULE_PARM_DESC(power_signal, "Power button sends this signal to init");14 15static 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};20MODULE_DEVICE_TABLE(acpi, tiny_power_button_device_ids);21 22static void acpi_tiny_power_button_notify(acpi_handle handle, u32 event, void *data)23{24 kill_cad_pid(power_signal, 1);25}26 27static void acpi_tiny_power_button_notify_run(void *not_used)28{29 acpi_tiny_power_button_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, NULL);30}31 32static u32 acpi_tiny_power_button_event(void *not_used)33{34 acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_tiny_power_button_notify_run, NULL);35 return ACPI_INTERRUPT_HANDLED;36}37 38static int acpi_tiny_power_button_add(struct acpi_device *device)39{40 acpi_status status;41 42 if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON) {43 status = acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,44 acpi_tiny_power_button_event,45 NULL);46 } else {47 status = acpi_install_notify_handler(device->handle,48 ACPI_DEVICE_NOTIFY,49 acpi_tiny_power_button_notify,50 NULL);51 }52 if (ACPI_FAILURE(status))53 return -ENODEV;54 55 return 0;56}57 58static void acpi_tiny_power_button_remove(struct acpi_device *device)59{60 if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON) {61 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,62 acpi_tiny_power_button_event);63 } else {64 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,65 acpi_tiny_power_button_notify);66 }67 acpi_os_wait_events_complete();68}69 70static struct acpi_driver acpi_tiny_power_button_driver = {71 .name = "tiny-power-button",72 .class = "tiny-power-button",73 .ids = tiny_power_button_device_ids,74 .ops = {75 .add = acpi_tiny_power_button_add,76 .remove = acpi_tiny_power_button_remove,77 },78};79 80module_acpi_driver(acpi_tiny_power_button_driver);81