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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Driver for the LID cover switch of the Surface 3
4 *
5 * Copyright (c) 2016 Red Hat Inc.
6 */
7
8
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/slab.h>
12
13#include <linux/acpi.h>
14#include <linux/dmi.h>
15#include <linux/input.h>
16#include <linux/mutex.h>
17#include <linux/platform_device.h>
18#include <linux/spi/spi.h>
19
20MODULE_AUTHOR("Benjamin Tissoires <[email protected]>");
21MODULE_DESCRIPTION("Surface 3 platform driver");
22MODULE_LICENSE("GPL");
23
24#define ACPI_BUTTON_HID_LID "PNP0C0D"
25#define SPI_CTL_OBJ_NAME "SPI"
26#define SPI_TS_OBJ_NAME "NTRG"
27
28#define SURFACE3_LID_GUID "F7CC25EC-D20B-404C-8903-0ED4359C18AE"
29
30MODULE_ALIAS("wmi:" SURFACE3_LID_GUID);
31
32static const struct dmi_system_id surface3_dmi_table[] = {
33#if defined(CONFIG_X86)
34 {
35 .matches = {
36 DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
37 DMI_MATCH(DMI_PRODUCT_NAME, "Surface 3"),
38 },
39 },
40#endif
41 { }
42};
43
44struct surface3_wmi {
45 struct acpi_device *touchscreen_adev;
46 struct acpi_device *pnp0c0d_adev;
47 struct acpi_hotplug_context hp;
48 struct input_dev *input;
49};
50
51static struct platform_device *s3_wmi_pdev;
52
53static struct surface3_wmi s3_wmi;
54
55static DEFINE_MUTEX(s3_wmi_lock);
56
57static int s3_wmi_query_block(const char *guid, int instance, int *ret)
58{
59 struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER, NULL };
60 union acpi_object *obj = NULL;
61 acpi_status status;
62 int error = 0;
63
64 mutex_lock(&s3_wmi_lock);
65 status = wmi_query_block(guid, instance, &output);
66 if (ACPI_FAILURE(status)) {
67 error = -EIO;
68 goto out_free_unlock;
69 }
70
71 obj = output.pointer;
72
73 if (!obj || obj->type != ACPI_TYPE_INTEGER) {
74 if (obj) {
75 pr_err("query block returned object type: %d - buffer length:%d\n",
76 obj->type,
77 obj->type == ACPI_TYPE_BUFFER ?
78 obj->buffer.length : 0);
79 }
80 error = -EINVAL;
81 goto out_free_unlock;
82 }
83 *ret = obj->integer.value;
84 out_free_unlock:
85 kfree(obj);
86 mutex_unlock(&s3_wmi_lock);
87 return error;
88}
89
90static inline int s3_wmi_query_lid(int *ret)
91{
92 return s3_wmi_query_block(SURFACE3_LID_GUID, 0, ret);
93}
94
95static int s3_wmi_send_lid_state(void)
96{
97 int ret, lid_sw;
98
99 ret = s3_wmi_query_lid(&lid_sw);
100 if (ret)
101 return ret;
102
103 input_report_switch(s3_wmi.input, SW_LID, lid_sw);
104 input_sync(s3_wmi.input);
105
106 return 0;
107}
108
109static int s3_wmi_hp_notify(struct acpi_device *adev, u32 value)
110{
111 return s3_wmi_send_lid_state();
112}
113
114static acpi_status s3_wmi_attach_spi_device(acpi_handle handle,
115 u32 level,
116 void *data,
117 void **return_value)
118{
119 struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
120 struct acpi_device **ts_adev = data;
121
122 if (!adev || strncmp(acpi_device_bid(adev), SPI_TS_OBJ_NAME,
123 strlen(SPI_TS_OBJ_NAME)))
124 return AE_OK;
125
126 if (*ts_adev) {
127 pr_err("duplicate entry %s\n", SPI_TS_OBJ_NAME);
128 return AE_OK;
129 }
130
131 *ts_adev = adev;
132
133 return AE_OK;
134}
135
136static int s3_wmi_check_platform_device(struct device *dev, void *data)
137{
138 struct acpi_device *adev = ACPI_COMPANION(dev);
139 struct acpi_device *ts_adev = NULL;
140 acpi_status status;
141
142 /* ignore non ACPI devices */
143 if (!adev)
144 return 0;
145
146 /* check for LID ACPI switch */
147 if (!strcmp(ACPI_BUTTON_HID_LID, acpi_device_hid(adev))) {
148 s3_wmi.pnp0c0d_adev = adev;
149 return 0;
150 }
151
152 /* ignore non SPI controllers */
153 if (strncmp(acpi_device_bid(adev), SPI_CTL_OBJ_NAME,
154 strlen(SPI_CTL_OBJ_NAME)))
155 return 0;
156
157 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, adev->handle, 1,
158 s3_wmi_attach_spi_device, NULL,
159 &ts_adev, NULL);
160 if (ACPI_FAILURE(status))
161 dev_warn(dev, "failed to enumerate SPI slaves\n");
162
163 if (!ts_adev)
164 return 0;
165
166 s3_wmi.touchscreen_adev = ts_adev;
167
168 return 0;
169}
170
171static int s3_wmi_create_and_register_input(struct platform_device *pdev)
172{
173 struct input_dev *input;
174 int error;
175
176 input = devm_input_allocate_device(&pdev->dev);
177 if (!input)
178 return -ENOMEM;
179
180 input->name = "Lid Switch";
181 input->phys = "button/input0";
182 input->id.bustype = BUS_HOST;
183 input->id.product = 0x0005;
184
185 input_set_capability(input, EV_SW, SW_LID);
186
187 error = input_register_device(input);
188 if (error)
189 return error;
190
191 s3_wmi.input = input;
192
193 return 0;
194}
195
196static int __init s3_wmi_probe(struct platform_device *pdev)
197{
198 int error;
199
200 if (!dmi_check_system(surface3_dmi_table))
201 return -ENODEV;
202
203 memset(&s3_wmi, 0, sizeof(s3_wmi));
204
205 bus_for_each_dev(&platform_bus_type, NULL, NULL,
206 s3_wmi_check_platform_device);
207
208 if (!s3_wmi.touchscreen_adev)
209 return -ENODEV;
210
211 acpi_bus_trim(s3_wmi.pnp0c0d_adev);
212
213 error = s3_wmi_create_and_register_input(pdev);
214 if (error)
215 goto restore_acpi_lid;
216
217 acpi_initialize_hp_context(s3_wmi.touchscreen_adev, &s3_wmi.hp,
218 s3_wmi_hp_notify, NULL);
219
220 s3_wmi_send_lid_state();
221
222 return 0;
223
224 restore_acpi_lid:
225 acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
226 return error;
227}
228
229static void s3_wmi_remove(struct platform_device *device)
230{
231 /* remove the hotplug context from the acpi device */
232 s3_wmi.touchscreen_adev->hp = NULL;
233
234 /* reinstall the actual PNPC0C0D LID default handle */
235 acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
236}
237
238static int __maybe_unused s3_wmi_resume(struct device *dev)
239{
240 s3_wmi_send_lid_state();
241 return 0;
242}
243static SIMPLE_DEV_PM_OPS(s3_wmi_pm, NULL, s3_wmi_resume);
244
245static struct platform_driver s3_wmi_driver = {
246 .driver = {
247 .name = "surface3-wmi",
248 .pm = &s3_wmi_pm,
249 },
250 .remove = s3_wmi_remove,
251};
252
253static int __init s3_wmi_init(void)
254{
255 int error;
256
257 s3_wmi_pdev = platform_device_alloc("surface3-wmi", -1);
258 if (!s3_wmi_pdev)
259 return -ENOMEM;
260
261 error = platform_device_add(s3_wmi_pdev);
262 if (error)
263 goto err_device_put;
264
265 error = platform_driver_probe(&s3_wmi_driver, s3_wmi_probe);
266 if (error)
267 goto err_device_del;
268
269 pr_info("Surface 3 WMI Extras loaded\n");
270 return 0;
271
272 err_device_del:
273 platform_device_del(s3_wmi_pdev);
274 err_device_put:
275 platform_device_put(s3_wmi_pdev);
276 return error;
277}
278
279static void __exit s3_wmi_exit(void)
280{
281 platform_device_unregister(s3_wmi_pdev);
282 platform_driver_unregister(&s3_wmi_driver);
283}
284
285module_init(s3_wmi_init);
286module_exit(s3_wmi_exit);