summaryrefslogtreecommitdiff
path: root/drivers/platform/x86/surfacepro3_button.c
blob: d8afed5db94c59f69f58e63e24e5976e9fae2ee7 (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
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
// SPDX-License-Identifier: GPL-2.0-only
/*
 * power/home/volume button support for
 * Microsoft Surface Pro 3/4 tablet.
 *
 * Copyright (c) 2015 Intel Corporation.
 * All rights reserved.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/input.h>
#include <linux/acpi.h>
#include <acpi/button.h>

#define SURFACE_PRO3_BUTTON_HID		"MSHW0028"
#define SURFACE_PRO4_BUTTON_HID		"MSHW0040"
#define SURFACE_BUTTON_OBJ_NAME		"VGBI"
#define SURFACE_BUTTON_DEVICE_NAME	"Surface Pro 3/4 Buttons"

#define MSHW0040_DSM_REVISION		0x01
#define MSHW0040_DSM_GET_OMPR		0x02	// get OEM Platform Revision
static const guid_t MSHW0040_DSM_UUID =
	GUID_INIT(0x6fd05c69, 0xcde3, 0x49f4, 0x95, 0xed, 0xab, 0x16, 0x65,
		  0x49, 0x80, 0x35);

#define SURFACE_BUTTON_NOTIFY_TABLET_MODE	0xc8

#define SURFACE_BUTTON_NOTIFY_PRESS_POWER	0xc6
#define SURFACE_BUTTON_NOTIFY_RELEASE_POWER	0xc7

#define SURFACE_BUTTON_NOTIFY_PRESS_HOME	0xc4
#define SURFACE_BUTTON_NOTIFY_RELEASE_HOME	0xc5

#define SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_UP	0xc0
#define SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_UP	0xc1

#define SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_DOWN		0xc2
#define SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_DOWN	0xc3

ACPI_MODULE_NAME("surface pro 3 button");

MODULE_AUTHOR("Chen Yu");
MODULE_DESCRIPTION("Surface Pro3 Button Driver");
MODULE_LICENSE("GPL v2");

/*
 * Power button, Home button, Volume buttons support is supposed to
 * be covered by drivers/input/misc/soc_button_array.c, which is implemented
 * according to "Windows ACPI Design Guide for SoC Platforms".
 * However surface pro3 seems not to obey the specs, instead it uses
 * device VGBI(MSHW0028) for dispatching the events.
 * We choose acpi_driver rather than platform_driver/i2c_driver because
 * although VGBI has an i2c resource connected to i2c controller, it
 * is not embedded in any i2c controller's scope, thus neither platform_device
 * will be created, nor i2c_client will be enumerated, we have to use
 * acpi_driver.
 */
static const struct acpi_device_id surface_button_device_ids[] = {
	{SURFACE_PRO3_BUTTON_HID,    0},
	{SURFACE_PRO4_BUTTON_HID,    0},
	{"", 0},
};
MODULE_DEVICE_TABLE(acpi, surface_button_device_ids);

struct surface_button {
	unsigned int type;
	struct input_dev *input;
	char phys[32];			/* for input device */
	unsigned long pushed;
	bool suspended;
};

static void surface_button_notify(struct acpi_device *device, u32 event)
{
	struct surface_button *button = acpi_driver_data(device);
	struct input_dev *input;
	int key_code = KEY_RESERVED;
	bool pressed = false;

	switch (event) {
	/* Power button press,release handle */
	case SURFACE_BUTTON_NOTIFY_PRESS_POWER:
		pressed = true;
		fallthrough;
	case SURFACE_BUTTON_NOTIFY_RELEASE_POWER:
		key_code = KEY_POWER;
		break;
	/* Home button press,release handle */
	case SURFACE_BUTTON_NOTIFY_PRESS_HOME:
		pressed = true;
		fallthrough;
	case SURFACE_BUTTON_NOTIFY_RELEASE_HOME:
		key_code = KEY_LEFTMETA;
		break;
	/* Volume up button press,release handle */
	case SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_UP:
		pressed = true;
		fallthrough;
	case SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_UP:
		key_code = KEY_VOLUMEUP;
		break;
	/* Volume down button press,release handle */
	case SURFACE_BUTTON_NOTIFY_PRESS_VOLUME_DOWN:
		pressed = true;
		fallthrough;
	case SURFACE_BUTTON_NOTIFY_RELEASE_VOLUME_DOWN:
		key_code = KEY_VOLUMEDOWN;
		break;
	case SURFACE_BUTTON_NOTIFY_TABLET_MODE:
		dev_warn_once(&device->dev, "Tablet mode is not supported\n");
		break;
	default:
		dev_info_ratelimited(&device->dev,
				     "Unsupported event [0x%x]\n", event);
		break;
	}
	input = button->input;
	if (key_code == KEY_RESERVED)
		return;
	if (pressed)
		pm_wakeup_dev_event(&device->dev, 0, button->suspended);
	if (button->suspended)
		return;
	input_report_key(input, key_code, pressed?1:0);
	input_sync(input);
}

#ifdef CONFIG_PM_SLEEP
static int surface_button_suspend(struct device *dev)
{
	struct acpi_device *device = to_acpi_device(dev);
	struct surface_button *button = acpi_driver_data(device);

	button->suspended = true;
	return 0;
}

static int surface_button_resume(struct device *dev)
{
	struct acpi_device *device = to_acpi_device(dev);
	struct surface_button *button = acpi_driver_data(device);

	button->suspended = false;
	return 0;
}
#endif

/*
 * Surface Pro 4 and Surface Book 2 / Surface Pro 2017 use the same device
 * ID (MSHW0040) for the power/volume buttons. Make sure this is the right
 * device by checking for the _DSM method and OEM Platform Revision.
 *
 * Returns true if the driver should bind to this device, i.e. the device is
 * either MSWH0028 (Pro 3) or MSHW0040 on a Pro 4 or Book 1.
 */
static bool surface_button_check_MSHW0040(struct acpi_device *dev)
{
	acpi_handle handle = dev->handle;
	union acpi_object *result;
	u64 oem_platform_rev = 0;	// valid revisions are nonzero

	// get OEM platform revision
	result = acpi_evaluate_dsm_typed(handle, &MSHW0040_DSM_UUID,
					 MSHW0040_DSM_REVISION,
					 MSHW0040_DSM_GET_OMPR,
					 NULL, ACPI_TYPE_INTEGER);

	/*
	 * If evaluating the _DSM fails, the method is not present. This means
	 * that we have either MSHW0028 or MSHW0040 on Pro 4 or Book 1, so we
	 * should use this driver. We use revision 0 indicating it is
	 * unavailable.
	 */

	if (result) {
		oem_platform_rev = result->integer.value;
		ACPI_FREE(result);
	}

	dev_dbg(&dev->dev, "OEM Platform Revision %llu\n", oem_platform_rev);

	return oem_platform_rev == 0;
}


static int surface_button_add(struct acpi_device *device)
{
	struct surface_button *button;
	struct input_dev *input;
	const char *hid = acpi_device_hid(device);
	char *name;
	int error;

	if (strncmp(acpi_device_bid(device), SURFACE_BUTTON_OBJ_NAME,
	    strlen(SURFACE_BUTTON_OBJ_NAME)))
		return -ENODEV;

	if (!surface_button_check_MSHW0040(device))
		return -ENODEV;

	button = kzalloc(sizeof(struct surface_button), GFP_KERNEL);
	if (!button)
		return -ENOMEM;

	device->driver_data = button;
	button->input = input = input_allocate_device();
	if (!input) {
		error = -ENOMEM;
		goto err_free_button;
	}

	name = acpi_device_name(device);
	strcpy(name, SURFACE_BUTTON_DEVICE_NAME);
	snprintf(button->phys, sizeof(button->phys), "%s/buttons", hid);

	input->name = name;
	input->phys = button->phys;
	input->id.bustype = BUS_HOST;
	input->dev.parent = &device->dev;
	input_set_capability(input, EV_KEY, KEY_POWER);
	input_set_capability(input, EV_KEY, KEY_LEFTMETA);
	input_set_capability(input, EV_KEY, KEY_VOLUMEUP);
	input_set_capability(input, EV_KEY, KEY_VOLUMEDOWN);

	error = input_register_device(input);
	if (error)
		goto err_free_input;

	device_init_wakeup(&device->dev, true);
	dev_info(&device->dev,
			"%s [%s]\n", name, acpi_device_bid(device));
	return 0;

 err_free_input:
	input_free_device(input);
 err_free_button:
	kfree(button);
	return error;
}

static int surface_button_remove(struct acpi_device *device)
{
	struct surface_button *button = acpi_driver_data(device);

	input_unregister_device(button->input);
	kfree(button);
	return 0;
}

static SIMPLE_DEV_PM_OPS(surface_button_pm,
		surface_button_suspend, surface_button_resume);

static struct acpi_driver surface_button_driver = {
	.name = "surface_pro3_button",
	.class = "SurfacePro3",
	.ids = surface_button_device_ids,
	.ops = {
		.add = surface_button_add,
		.remove = surface_button_remove,
		.notify = surface_button_notify,
	},
	.drv.pm = &surface_button_pm,
};

module_acpi_driver(surface_button_driver);