summaryrefslogtreecommitdiff
path: root/drivers/platform/x86/intel-vbtn.c
blob: 554e82ebe83ca1fd102affcc5357bea0fa429c56 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
/*
 *  Intel Virtual Button driver for Windows 8.1+
 *
 *  Copyright (C) 2016 AceLan Kao <acelan.kao@canonical.com>
 *  Copyright (C) 2016 Alex Hung <alex.hung@canonical.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/input.h>
#include <linux/platform_device.h>
#include <linux/input/sparse-keymap.h>
#include <linux/acpi.h>
#include <acpi/acpi_bus.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("AceLan Kao");

static const struct acpi_device_id intel_vbtn_ids[] = {
	{"INT33D6", 0},
	{"", 0},
};

/* In theory, these are HID usages. */
static const struct key_entry intel_vbtn_keymap[] = {
	{ KE_IGNORE, 0xC0, { KEY_POWER } },	/* power key press */
	{ KE_KEY, 0xC1, { KEY_POWER } },	/* power key release */
	{ KE_END },
};

struct intel_vbtn_priv {
	struct input_dev *input_dev;
};

static int intel_vbtn_input_setup(struct platform_device *device)
{
	struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
	int ret;

	priv->input_dev = devm_input_allocate_device(&device->dev);
	if (!priv->input_dev)
		return -ENOMEM;

	ret = sparse_keymap_setup(priv->input_dev, intel_vbtn_keymap, NULL);
	if (ret)
		return ret;

	priv->input_dev->dev.parent = &device->dev;
	priv->input_dev->name = "Intel Virtual Button driver";
	priv->input_dev->id.bustype = BUS_HOST;

	return input_register_device(priv->input_dev);
}

static void notify_handler(acpi_handle handle, u32 event, void *context)
{
	struct platform_device *device = context;
	struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);

	if (!sparse_keymap_report_event(priv->input_dev, event, 1, true))
		dev_info(&device->dev, "unknown event index 0x%x\n",
			 event);
}

static int intel_vbtn_probe(struct platform_device *device)
{
	acpi_handle handle = ACPI_HANDLE(&device->dev);
	struct intel_vbtn_priv *priv;
	acpi_status status;
	int err;

	status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
	if (ACPI_FAILURE(status)) {
		dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
		return -ENODEV;
	}

	priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;
	dev_set_drvdata(&device->dev, priv);

	err = intel_vbtn_input_setup(device);
	if (err) {
		pr_err("Failed to setup Intel Virtual Button\n");
		return err;
	}

	status = acpi_install_notify_handler(handle,
					     ACPI_DEVICE_NOTIFY,
					     notify_handler,
					     device);
	if (ACPI_FAILURE(status))
		return -EBUSY;

	return 0;
}

static int intel_vbtn_remove(struct platform_device *device)
{
	acpi_handle handle = ACPI_HANDLE(&device->dev);

	acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);

	/*
	 * Even if we failed to shut off the event stream, we can still
	 * safely detach from the device.
	 */
	return 0;
}

static struct platform_driver intel_vbtn_pl_driver = {
	.driver = {
		.name = "intel-vbtn",
		.acpi_match_table = intel_vbtn_ids,
	},
	.probe = intel_vbtn_probe,
	.remove = intel_vbtn_remove,
};
MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids);

static acpi_status __init
check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
{
	const struct acpi_device_id *ids = context;
	struct acpi_device *dev;

	if (acpi_bus_get_device(handle, &dev) != 0)
		return AE_OK;

	if (acpi_match_device_ids(dev, ids) == 0)
		if (acpi_create_platform_device(dev, NULL))
			dev_info(&dev->dev,
				 "intel-vbtn: created platform device\n");

	return AE_OK;
}

static int __init intel_vbtn_init(void)
{
	acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
			    ACPI_UINT32_MAX, check_acpi_dev, NULL,
			    (void *)intel_vbtn_ids, NULL);

	return platform_driver_register(&intel_vbtn_pl_driver);
}
module_init(intel_vbtn_init);

static void __exit intel_vbtn_exit(void)
{
	platform_driver_unregister(&intel_vbtn_pl_driver);
}
module_exit(intel_vbtn_exit);