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
19struct adv_swbutton {
20	struct input_dev *input;
21	char phys[32];
22};
23
24/*-------------------------------------------------------------------------
25 *                               Driver Interface
26 *--------------------------------------------------------------------------
27 */
28static 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
47static int adv_swbutton_probe(struct platform_device *device)
48{
49	struct adv_swbutton *button;
50	struct input_dev *input;
51	acpi_handle handle = ACPI_HANDLE(&device->dev);
52	acpi_status status;
53	int error;
54
55	button = devm_kzalloc(&device->dev, sizeof(*button), GFP_KERNEL);
56	if (!button)
57		return -ENOMEM;
58
59	dev_set_drvdata(&device->dev, button);
60
61	input = devm_input_allocate_device(&device->dev);
62	if (!input)
63		return -ENOMEM;
64
65	button->input = input;
66	snprintf(button->phys, sizeof(button->phys), "%s/button/input0", ACPI_BUTTON_HID_SWBTN);
67
68	input->name = "Advantech Software Button";
69	input->phys = button->phys;
70	input->id.bustype = BUS_HOST;
71	input->dev.parent = &device->dev;
72	set_bit(EV_REP, input->evbit);
73	input_set_capability(input, EV_KEY, KEY_PROG1);
74
75	error = input_register_device(input);
76	if (error)
77		return error;
78
79	device_init_wakeup(&device->dev, true);
80
81	status = acpi_install_notify_handler(handle,
82					     ACPI_DEVICE_NOTIFY,
83					     adv_swbutton_notify,
84					     device);
85	if (ACPI_FAILURE(status)) {
86		dev_err(&device->dev, "Error installing notify handler\n");
87		return -EIO;
88	}
89
90	return 0;
91}
92
93static void adv_swbutton_remove(struct platform_device *device)
94{
95	acpi_handle handle = ACPI_HANDLE(&device->dev);
96
97	acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY,
98				   adv_swbutton_notify);
99}
100
101static const struct acpi_device_id button_device_ids[] = {
102	{ACPI_BUTTON_HID_SWBTN, 0},
103	{"", 0},
104};
105MODULE_DEVICE_TABLE(acpi, button_device_ids);
106
107static struct platform_driver adv_swbutton_driver = {
108	.driver = {
109		.name = "adv_swbutton",
110		.acpi_match_table = button_device_ids,
111	},
112	.probe = adv_swbutton_probe,
113	.remove_new = adv_swbutton_remove,
114};
115module_platform_driver(adv_swbutton_driver);
116
117MODULE_AUTHOR("Andrea Ho");
118MODULE_DESCRIPTION("Advantech ACPI SW Button Driver");
119MODULE_LICENSE("GPL v2");
120