summaryrefslogtreecommitdiff
path: root/drivers/platform/x86/surface3-wmi.c
blob: 25b176996cb793a789214a1a1237910b01cd3673 (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
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
/*
 *  Driver for the LID cover switch of the Surface 3
 *
 *  Copyright (c) 2016 Red Hat Inc.
 */

/*
 * 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; version 2 of the License.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>

#include <linux/acpi.h>
#include <linux/dmi.h>
#include <linux/input.h>
#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>

MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@redhat.com>");
MODULE_DESCRIPTION("Surface 3 platform driver");
MODULE_LICENSE("GPL");

#define ACPI_BUTTON_HID_LID		"PNP0C0D"
#define SPI_CTL_OBJ_NAME		"SPI"
#define SPI_TS_OBJ_NAME			"NTRG"

#define SURFACE3_LID_GUID "F7CC25EC-D20B-404C-8903-0ED4359C18AE"

MODULE_ALIAS("wmi:" SURFACE3_LID_GUID);

static const struct dmi_system_id surface3_dmi_table[] = {
#if defined(CONFIG_X86)
	{
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
			DMI_MATCH(DMI_PRODUCT_NAME, "Surface 3"),
		},
	},
#endif
	{ }
};

struct surface3_wmi {
	struct acpi_device *touchscreen_adev;
	struct acpi_device *pnp0c0d_adev;
	struct acpi_hotplug_context hp;
	struct input_dev *input;
};

static struct platform_device *s3_wmi_pdev;

static struct surface3_wmi s3_wmi;

static DEFINE_MUTEX(s3_wmi_lock);

static int s3_wmi_query_block(const char *guid, int instance, int *ret)
{
	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
	acpi_status status;
	union acpi_object *obj;
	int error = 0;

	mutex_lock(&s3_wmi_lock);
	status = wmi_query_block(guid, instance, &output);

	obj = output.pointer;

	if (!obj || obj->type != ACPI_TYPE_INTEGER) {
		if (obj) {
			pr_err("query block returned object type: %d - buffer length:%d\n",
			       obj->type,
			       obj->type == ACPI_TYPE_BUFFER ?
						obj->buffer.length : 0);
		}
		error = -EINVAL;
		goto out_free_unlock;
	}
	*ret = obj->integer.value;
 out_free_unlock:
	kfree(obj);
	mutex_unlock(&s3_wmi_lock);
	return error;
}

static inline int s3_wmi_query_lid(int *ret)
{
	return s3_wmi_query_block(SURFACE3_LID_GUID, 0, ret);
}

static int s3_wmi_send_lid_state(void)
{
	int ret, lid_sw;

	ret = s3_wmi_query_lid(&lid_sw);
	if (ret)
		return ret;

	input_report_switch(s3_wmi.input, SW_LID, lid_sw);
	input_sync(s3_wmi.input);

	return 0;
}

static int s3_wmi_hp_notify(struct acpi_device *adev, u32 value)
{
	return s3_wmi_send_lid_state();
}

static acpi_status s3_wmi_attach_spi_device(acpi_handle handle,
					    u32 level,
					    void *data,
					    void **return_value)
{
	struct acpi_device *adev, **ts_adev;

	if (acpi_bus_get_device(handle, &adev))
		return AE_OK;

	ts_adev = data;

	if (strncmp(acpi_device_bid(adev), SPI_TS_OBJ_NAME,
	    strlen(SPI_TS_OBJ_NAME)))
		return AE_OK;

	if (*ts_adev) {
		pr_err("duplicate entry %s\n", SPI_TS_OBJ_NAME);
		return AE_OK;
	}

	*ts_adev = adev;

	return AE_OK;
}

static int s3_wmi_check_platform_device(struct device *dev, void *data)
{
	struct acpi_device *adev, *ts_adev = NULL;
	acpi_handle handle;
	acpi_status status;

	/* ignore non ACPI devices */
	handle = ACPI_HANDLE(dev);
	if (!handle || acpi_bus_get_device(handle, &adev))
		return 0;

	/* check for LID ACPI switch */
	if (!strcmp(ACPI_BUTTON_HID_LID, acpi_device_hid(adev))) {
		s3_wmi.pnp0c0d_adev = adev;
		return 0;
	}

	/* ignore non SPI controllers */
	if (strncmp(acpi_device_bid(adev), SPI_CTL_OBJ_NAME,
	    strlen(SPI_CTL_OBJ_NAME)))
		return 0;

	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
				     s3_wmi_attach_spi_device, NULL,
				     &ts_adev, NULL);
	if (ACPI_FAILURE(status))
		dev_warn(dev, "failed to enumerate SPI slaves\n");

	if (!ts_adev)
		return 0;

	s3_wmi.touchscreen_adev = ts_adev;

	return 0;
}

static int s3_wmi_create_and_register_input(struct platform_device *pdev)
{
	struct input_dev *input;
	int error;

	input = devm_input_allocate_device(&pdev->dev);
	if (!input)
		return -ENOMEM;

	input->name = "Lid Switch";
	input->phys = "button/input0";
	input->id.bustype = BUS_HOST;
	input->id.product = 0x0005;

	input_set_capability(input, EV_SW, SW_LID);

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

	s3_wmi.input = input;

	return 0;
 out_err:
	input_free_device(s3_wmi.input);
	return error;
}

static int __init s3_wmi_probe(struct platform_device *pdev)
{
	int error;

	if (!dmi_check_system(surface3_dmi_table))
		return -ENODEV;

	memset(&s3_wmi, 0, sizeof(s3_wmi));

	bus_for_each_dev(&platform_bus_type, NULL, NULL,
			 s3_wmi_check_platform_device);

	if (!s3_wmi.touchscreen_adev)
		return -ENODEV;

	acpi_bus_trim(s3_wmi.pnp0c0d_adev);

	error = s3_wmi_create_and_register_input(pdev);
	if (error)
		goto restore_acpi_lid;

	acpi_initialize_hp_context(s3_wmi.touchscreen_adev, &s3_wmi.hp,
				   s3_wmi_hp_notify, NULL);

	s3_wmi_send_lid_state();

	return 0;

 restore_acpi_lid:
	acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
	return error;
}

static int s3_wmi_remove(struct platform_device *device)
{
	/* remove the hotplug context from the acpi device */
	s3_wmi.touchscreen_adev->hp = NULL;

	/* reinstall the actual PNPC0C0D LID default handle */
	acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
	return 0;
}

static int __maybe_unused s3_wmi_resume(struct device *dev)
{
	s3_wmi_send_lid_state();
	return 0;
}
static SIMPLE_DEV_PM_OPS(s3_wmi_pm, NULL, s3_wmi_resume);

static struct platform_driver s3_wmi_driver = {
	.driver = {
		.name = "surface3-wmi",
		.pm = &s3_wmi_pm,
	},
	.remove = s3_wmi_remove,
};

static int __init s3_wmi_init(void)
{
	int error;

	s3_wmi_pdev = platform_device_alloc("surface3-wmi", -1);
	if (!s3_wmi_pdev)
		return -ENOMEM;

	error = platform_device_add(s3_wmi_pdev);
	if (error)
		goto err_device_put;

	error = platform_driver_probe(&s3_wmi_driver, s3_wmi_probe);
	if (error)
		goto err_device_del;

	pr_info("Surface 3 WMI Extras loaded\n");
	return 0;

 err_device_del:
	platform_device_del(s3_wmi_pdev);
 err_device_put:
	platform_device_put(s3_wmi_pdev);
	return error;
}

static void __exit s3_wmi_exit(void)
{
	platform_device_unregister(s3_wmi_pdev);
	platform_driver_unregister(&s3_wmi_driver);
}

module_init(s3_wmi_init);
module_exit(s3_wmi_exit);