1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * adv_swbutton.c - Software Button Interface Driver.
4 *
5 * (C) Copyright 2020 Advantech Corporation, Inc
6 *
7 */
8 #include <linux/kernel.h>
9 #include <linux/module.h>
10 #include <linux/input.h>
11 #include <linux/acpi.h>
12 #include <linux/platform_device.h>
13
14 #define ACPI_BUTTON_HID_SWBTN "AHC0310"
15
16 #define ACPI_BUTTON_NOTIFY_SWBTN_RELEASE 0x86
17 #define ACPI_BUTTON_NOTIFY_SWBTN_PRESSED 0x85
18
19 struct adv_swbutton {
20 struct input_dev *input;
21 char phys[32];
22 };
23
24 /*-------------------------------------------------------------------------
25 * Driver Interface
26 *--------------------------------------------------------------------------
27 */
adv_swbutton_notify(acpi_handle handle,u32 event,void * context)28 static void adv_swbutton_notify(acpi_handle handle, u32 event, void *context)
29 {
30 struct platform_device *device = context;
31 struct adv_swbutton *button = dev_get_drvdata(&device->dev);
32
33 switch (event) {
34 case ACPI_BUTTON_NOTIFY_SWBTN_RELEASE:
35 input_report_key(button->input, KEY_PROG1, 0);
36 input_sync(button->input);
37 break;
38 case ACPI_BUTTON_NOTIFY_SWBTN_PRESSED:
39 input_report_key(button->input, KEY_PROG1, 1);
40 input_sync(button->input);
41 break;
42 default:
43 dev_dbg(&device->dev, "Unsupported event [0x%x]\n", event);
44 }
45 }
46
adv_swbutton_probe(struct platform_device * device)47 static int adv_swbutton_probe(struct platform_device *device)
48 {
49 struct adv_swbutton *button;
50 struct input_dev *input;
51 acpi_handle handle;
52 acpi_status status;
53 int error;
54
55 handle = ACPI_HANDLE(&device->dev);
56 if (!handle)
57 return -ENODEV;
58
59 button = devm_kzalloc(&device->dev, sizeof(*button), GFP_KERNEL);
60 if (!button)
61 return -ENOMEM;
62
63 dev_set_drvdata(&device->dev, button);
64
65 input = devm_input_allocate_device(&device->dev);
66 if (!input)
67 return -ENOMEM;
68
69 button->input = input;
70 snprintf(button->phys, sizeof(button->phys), "%s/button/input0", ACPI_BUTTON_HID_SWBTN);
71
72 input->name = "Advantech Software Button";
73 input->phys = button->phys;
74 input->id.bustype = BUS_HOST;
75 input->dev.parent = &device->dev;
76 set_bit(EV_REP, input->evbit);
77 input_set_capability(input, EV_KEY, KEY_PROG1);
78
79 error = input_register_device(input);
80 if (error)
81 return error;
82
83 device_init_wakeup(&device->dev, true);
84
85 status = acpi_install_notify_handler(handle,
86 ACPI_DEVICE_NOTIFY,
87 adv_swbutton_notify,
88 device);
89 if (ACPI_FAILURE(status)) {
90 dev_err(&device->dev, "Error installing notify handler\n");
91 return -EIO;
92 }
93
94 return 0;
95 }
96
adv_swbutton_remove(struct platform_device * device)97 static void adv_swbutton_remove(struct platform_device *device)
98 {
99 acpi_handle handle = ACPI_HANDLE(&device->dev);
100
101 acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY,
102 adv_swbutton_notify);
103 }
104
105 static const struct acpi_device_id button_device_ids[] = {
106 {ACPI_BUTTON_HID_SWBTN, 0},
107 {"", 0},
108 };
109 MODULE_DEVICE_TABLE(acpi, button_device_ids);
110
111 static struct platform_driver adv_swbutton_driver = {
112 .driver = {
113 .name = "adv_swbutton",
114 .acpi_match_table = button_device_ids,
115 },
116 .probe = adv_swbutton_probe,
117 .remove = adv_swbutton_remove,
118 };
119 module_platform_driver(adv_swbutton_driver);
120
121 MODULE_AUTHOR("Andrea Ho");
122 MODULE_DESCRIPTION("Advantech ACPI SW Button Driver");
123 MODULE_LICENSE("GPL v2");
124