summaryrefslogtreecommitdiffstats
path: root/drivers/platform/x86/intel-vbtn.c
blob: c13780b8dabbe089c24a2b5c323f1510f589153e (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
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
// SPDX-License-Identifier: GPL-2.0+
/*
 *  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>
 */

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

/* When NOT in tablet mode, VGBS returns with the flag 0x40 */
#define TABLET_MODE_FLAG 0x40

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_KEY, 0xC0, { KEY_POWER } },	/* power key press */
	{ KE_IGNORE, 0xC1, { KEY_POWER } },	/* power key release */
	{ KE_KEY, 0xC2, { KEY_LEFTMETA } },		/* 'Windows' key press */
	{ KE_KEY, 0xC3, { KEY_LEFTMETA } },		/* 'Windows' key release */
	{ KE_KEY, 0xC4, { KEY_VOLUMEUP } },		/* volume-up key press */
	{ KE_IGNORE, 0xC5, { KEY_VOLUMEUP } },		/* volume-up key release */
	{ KE_KEY, 0xC6, { KEY_VOLUMEDOWN } },		/* volume-down key press */
	{ KE_IGNORE, 0xC7, { KEY_VOLUMEDOWN } },	/* volume-down key release */
	{ KE_KEY,    0xC8, { KEY_ROTATE_LOCK_TOGGLE } },	/* rotate-lock key press */
	{ KE_KEY,    0xC9, { KEY_ROTATE_LOCK_TOGGLE } },	/* rotate-lock key release */
	{ KE_SW,     0xCC, { .sw = { SW_TABLET_MODE, 1 } } },	/* Tablet */
	{ KE_SW,     0xCD, { .sw = { SW_TABLET_MODE, 0 } } },	/* Laptop */
	{ KE_END },
};

struct intel_vbtn_priv {
	struct input_dev *input_dev;
	bool wakeup_mode;
};

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);
	unsigned int val = !(event & 1); /* Even=press, Odd=release */
	const struct key_entry *ke_rel;
	bool autorelease;

	if (priv->wakeup_mode) {
		if (sparse_keymap_entry_from_scancode(priv->input_dev, event)) {
			pm_wakeup_hard_event(&device->dev);
			return;
		}
		goto out_unknown;
	}

	/*
	 * Even press events are autorelease if there is no corresponding odd
	 * release event, or if the odd event is KE_IGNORE.
	 */
	ke_rel = sparse_keymap_entry_from_scancode(priv->input_dev, event | 1);
	autorelease = val && (!ke_rel || ke_rel->type == KE_IGNORE);

	if (sparse_keymap_report_event(priv->input_dev, event, val, autorelease))
		return;

out_unknown:
	dev_dbg(&device->dev, "unknown event index 0x%x\n", event);
}

static void detect_tablet_mode(struct platform_device *device)
{
	const char *chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
	struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
	acpi_handle handle = ACPI_HANDLE(&device->dev);
	struct acpi_buffer vgbs_output = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *obj;
	acpi_status status;
	int m;

	if (!(chassis_type && strcmp(chassis_type, "31") == 0))
		goto out;

	status = acpi_evaluate_object(handle, "VGBS", NULL, &vgbs_output);
	if (ACPI_FAILURE(status))
		goto out;

	obj = vgbs_output.pointer;
	if (!(obj && obj->type == ACPI_TYPE_INTEGER))
		goto out;

	m = !(obj->integer.value & TABLET_MODE_FLAG);
	input_report_switch(priv->input_dev, SW_TABLET_MODE, m);
out:
	kfree(vgbs_output.pointer);
}

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;
	}

	detect_tablet_mode(device);

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

	device_init_wakeup(&device->dev, true);
	return 0;
}

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

	device_init_wakeup(&device->dev, false);
	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 int intel_vbtn_pm_prepare(struct device *dev)
{
	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);

	priv->wakeup_mode = true;
	return 0;
}

static int intel_vbtn_pm_resume(struct device *dev)
{
	struct intel_vbtn_priv *priv = dev_get_drvdata(dev);

	priv->wakeup_mode = false;
	return 0;
}

static const struct dev_pm_ops intel_vbtn_pm_ops = {
	.prepare = intel_vbtn_pm_prepare,
	.resume = intel_vbtn_pm_resume,
	.restore = intel_vbtn_pm_resume,
	.thaw = intel_vbtn_pm_resume,
};

static struct platform_driver intel_vbtn_pl_driver = {
	.driver = {
		.name = "intel-vbtn",
		.acpi_match_table = intel_vbtn_ids,
		.pm = &intel_vbtn_pm_ops,
	},
	.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);