1 // SPDX-License-Identifier: GPL-2.0-or-later
2 #include <linux/acpi.h>
3 #include <linux/module.h>
4 #include <linux/platform_device.h>
5 #include <linux/sched/signal.h>
6 #include <acpi/button.h>
7
8 MODULE_AUTHOR("Josh Triplett");
9 MODULE_DESCRIPTION("ACPI Tiny Power Button Driver");
10 MODULE_LICENSE("GPL");
11
12 static int power_signal __read_mostly = CONFIG_ACPI_TINY_POWER_BUTTON_SIGNAL;
13 module_param(power_signal, int, 0644);
14 MODULE_PARM_DESC(power_signal, "Power button sends this signal to init");
15
16 static const struct acpi_device_id tiny_power_button_device_ids[] = {
17 { ACPI_BUTTON_HID_POWER, 0 },
18 { ACPI_BUTTON_HID_POWERF, 0 },
19 { "", 0 },
20 };
21 MODULE_DEVICE_TABLE(acpi, tiny_power_button_device_ids);
22
acpi_tiny_power_button_notify(acpi_handle handle,u32 event,void * data)23 static void acpi_tiny_power_button_notify(acpi_handle handle, u32 event, void *data)
24 {
25 kill_cad_pid(power_signal, 1);
26 }
27
acpi_tiny_power_button_notify_run(void * not_used)28 static void acpi_tiny_power_button_notify_run(void *not_used)
29 {
30 acpi_tiny_power_button_notify(NULL, ACPI_FIXED_HARDWARE_EVENT, NULL);
31 }
32
acpi_tiny_power_button_event(void * not_used)33 static u32 acpi_tiny_power_button_event(void *not_used)
34 {
35 acpi_os_execute(OSL_NOTIFY_HANDLER, acpi_tiny_power_button_notify_run, NULL);
36 return ACPI_INTERRUPT_HANDLED;
37 }
38
acpi_tiny_power_button_probe(struct platform_device * pdev)39 static int acpi_tiny_power_button_probe(struct platform_device *pdev)
40 {
41 struct acpi_device *device;
42 acpi_status status;
43
44 device = ACPI_COMPANION(&pdev->dev);
45 if (!device)
46 return -ENODEV;
47
48 if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON) {
49 status = acpi_install_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
50 acpi_tiny_power_button_event,
51 NULL);
52 } else {
53 status = acpi_install_notify_handler(device->handle,
54 ACPI_DEVICE_NOTIFY,
55 acpi_tiny_power_button_notify,
56 NULL);
57 }
58 if (ACPI_FAILURE(status))
59 return -ENODEV;
60
61 return 0;
62 }
63
acpi_tiny_power_button_remove(struct platform_device * pdev)64 static void acpi_tiny_power_button_remove(struct platform_device *pdev)
65 {
66 struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
67
68 if (device->device_type == ACPI_BUS_TYPE_POWER_BUTTON) {
69 acpi_remove_fixed_event_handler(ACPI_EVENT_POWER_BUTTON,
70 acpi_tiny_power_button_event);
71 } else {
72 acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY,
73 acpi_tiny_power_button_notify);
74 }
75 acpi_os_wait_events_complete();
76 }
77
78 static struct platform_driver acpi_tiny_power_button_driver = {
79 .probe = acpi_tiny_power_button_probe,
80 .remove = acpi_tiny_power_button_remove,
81 .driver = {
82 .name = "acpi-tiny-power-button",
83 .acpi_match_table = tiny_power_button_device_ids,
84 },
85 };
86
87 module_platform_driver(acpi_tiny_power_button_driver);
88