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
acpi_tiny_power_button_notify(acpi_handle handle,u32 event,void * data)22 static void acpi_tiny_power_button_notify(acpi_handle handle, u32 event, void *data)
23 {
24 kill_cad_pid(power_signal, 1);
25 }
26
acpi_tiny_power_button_notify_run(void * not_used)27 static 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
acpi_tiny_power_button_event(void * not_used)32 static 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
acpi_tiny_power_button_add(struct acpi_device * device)38 static 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
acpi_tiny_power_button_remove(struct acpi_device * device)58 static 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
70 static 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
80 module_acpi_driver(acpi_tiny_power_button_driver);
81