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
20 MODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@redhat.com>");
21 MODULE_DESCRIPTION("Surface 3 platform driver");
22 MODULE_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
30 MODULE_ALIAS("wmi:" SURFACE3_LID_GUID);
31
32 static 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
44 struct 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
51 static struct platform_device *s3_wmi_pdev;
52
53 static struct surface3_wmi s3_wmi;
54
55 static DEFINE_MUTEX(s3_wmi_lock);
56
s3_wmi_query_block(const char * guid,int instance,int * ret)57 static 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
s3_wmi_query_lid(int * ret)90 static inline int s3_wmi_query_lid(int *ret)
91 {
92 return s3_wmi_query_block(SURFACE3_LID_GUID, 0, ret);
93 }
94
s3_wmi_send_lid_state(void)95 static 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
s3_wmi_hp_notify(struct acpi_device * adev,u32 value)109 static int s3_wmi_hp_notify(struct acpi_device *adev, u32 value)
110 {
111 return s3_wmi_send_lid_state();
112 }
113
s3_wmi_attach_spi_device(acpi_handle handle,u32 level,void * data,void ** return_value)114 static 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, **ts_adev;
120
121 if (acpi_bus_get_device(handle, &adev))
122 return AE_OK;
123
124 ts_adev = data;
125
126 if (strncmp(acpi_device_bid(adev), SPI_TS_OBJ_NAME,
127 strlen(SPI_TS_OBJ_NAME)))
128 return AE_OK;
129
130 if (*ts_adev) {
131 pr_err("duplicate entry %s\n", SPI_TS_OBJ_NAME);
132 return AE_OK;
133 }
134
135 *ts_adev = adev;
136
137 return AE_OK;
138 }
139
s3_wmi_check_platform_device(struct device * dev,void * data)140 static int s3_wmi_check_platform_device(struct device *dev, void *data)
141 {
142 struct acpi_device *adev = ACPI_COMPANION(dev);
143 struct acpi_device *ts_adev = NULL;
144 acpi_status status;
145
146 /* ignore non ACPI devices */
147 if (!adev)
148 return 0;
149
150 /* check for LID ACPI switch */
151 if (!strcmp(ACPI_BUTTON_HID_LID, acpi_device_hid(adev))) {
152 s3_wmi.pnp0c0d_adev = adev;
153 return 0;
154 }
155
156 /* ignore non SPI controllers */
157 if (strncmp(acpi_device_bid(adev), SPI_CTL_OBJ_NAME,
158 strlen(SPI_CTL_OBJ_NAME)))
159 return 0;
160
161 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, adev->handle, 1,
162 s3_wmi_attach_spi_device, NULL,
163 &ts_adev, NULL);
164 if (ACPI_FAILURE(status))
165 dev_warn(dev, "failed to enumerate SPI slaves\n");
166
167 if (!ts_adev)
168 return 0;
169
170 s3_wmi.touchscreen_adev = ts_adev;
171
172 return 0;
173 }
174
s3_wmi_create_and_register_input(struct platform_device * pdev)175 static int s3_wmi_create_and_register_input(struct platform_device *pdev)
176 {
177 struct input_dev *input;
178 int error;
179
180 input = devm_input_allocate_device(&pdev->dev);
181 if (!input)
182 return -ENOMEM;
183
184 input->name = "Lid Switch";
185 input->phys = "button/input0";
186 input->id.bustype = BUS_HOST;
187 input->id.product = 0x0005;
188
189 input_set_capability(input, EV_SW, SW_LID);
190
191 error = input_register_device(input);
192 if (error)
193 goto out_err;
194
195 s3_wmi.input = input;
196
197 return 0;
198 out_err:
199 input_free_device(s3_wmi.input);
200 return error;
201 }
202
s3_wmi_probe(struct platform_device * pdev)203 static int __init s3_wmi_probe(struct platform_device *pdev)
204 {
205 int error;
206
207 if (!dmi_check_system(surface3_dmi_table))
208 return -ENODEV;
209
210 memset(&s3_wmi, 0, sizeof(s3_wmi));
211
212 bus_for_each_dev(&platform_bus_type, NULL, NULL,
213 s3_wmi_check_platform_device);
214
215 if (!s3_wmi.touchscreen_adev)
216 return -ENODEV;
217
218 acpi_bus_trim(s3_wmi.pnp0c0d_adev);
219
220 error = s3_wmi_create_and_register_input(pdev);
221 if (error)
222 goto restore_acpi_lid;
223
224 acpi_initialize_hp_context(s3_wmi.touchscreen_adev, &s3_wmi.hp,
225 s3_wmi_hp_notify, NULL);
226
227 s3_wmi_send_lid_state();
228
229 return 0;
230
231 restore_acpi_lid:
232 acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
233 return error;
234 }
235
s3_wmi_remove(struct platform_device * device)236 static int s3_wmi_remove(struct platform_device *device)
237 {
238 /* remove the hotplug context from the acpi device */
239 s3_wmi.touchscreen_adev->hp = NULL;
240
241 /* reinstall the actual PNPC0C0D LID default handle */
242 acpi_bus_scan(s3_wmi.pnp0c0d_adev->handle);
243 return 0;
244 }
245
s3_wmi_resume(struct device * dev)246 static int __maybe_unused s3_wmi_resume(struct device *dev)
247 {
248 s3_wmi_send_lid_state();
249 return 0;
250 }
251 static SIMPLE_DEV_PM_OPS(s3_wmi_pm, NULL, s3_wmi_resume);
252
253 static struct platform_driver s3_wmi_driver = {
254 .driver = {
255 .name = "surface3-wmi",
256 .pm = &s3_wmi_pm,
257 },
258 .remove = s3_wmi_remove,
259 };
260
s3_wmi_init(void)261 static int __init s3_wmi_init(void)
262 {
263 int error;
264
265 s3_wmi_pdev = platform_device_alloc("surface3-wmi", -1);
266 if (!s3_wmi_pdev)
267 return -ENOMEM;
268
269 error = platform_device_add(s3_wmi_pdev);
270 if (error)
271 goto err_device_put;
272
273 error = platform_driver_probe(&s3_wmi_driver, s3_wmi_probe);
274 if (error)
275 goto err_device_del;
276
277 pr_info("Surface 3 WMI Extras loaded\n");
278 return 0;
279
280 err_device_del:
281 platform_device_del(s3_wmi_pdev);
282 err_device_put:
283 platform_device_put(s3_wmi_pdev);
284 return error;
285 }
286
s3_wmi_exit(void)287 static void __exit s3_wmi_exit(void)
288 {
289 platform_device_unregister(s3_wmi_pdev);
290 platform_driver_unregister(&s3_wmi_driver);
291 }
292
293 module_init(s3_wmi_init);
294 module_exit(s3_wmi_exit);
295