150472Speter// SPDX-License-Identifier: GPL-2.0-only
230842Sache/*
3272787Sngie *  Driver for the LID cover switch of the Surface 3
4272787Sngie *
5170758Sdelphij *  Copyright (c) 2016 Red Hat Inc.
6170758Sdelphij */
7170758Sdelphij
8279520Sbapt
9279520Sbapt#include <linux/kernel.h>
1030842Sache#include <linux/module.h>
1167Snate#include <linux/slab.h>
12170758Sdelphij
13170758Sdelphij#include <linux/acpi.h>
14170758Sdelphij#include <linux/dmi.h>
15170758Sdelphij#include <linux/input.h>
16170758Sdelphij#include <linux/mutex.h>
1730842Sache#include <linux/platform_device.h>
1830842Sache#include <linux/spi/spi.h>
1930842Sache
2030842SacheMODULE_AUTHOR("Benjamin Tissoires <benjamin.tissoires@redhat.com>");
21172593SobrienMODULE_DESCRIPTION("Surface 3 platform driver");
22172593SobrienMODULE_LICENSE("GPL");
23170758Sdelphij
24170758Sdelphij#define ACPI_BUTTON_HID_LID		"PNP0C0D"
25170758Sdelphij#define SPI_CTL_OBJ_NAME		"SPI"
26251468Sjkim#define SPI_TS_OBJ_NAME			"NTRG"
2767Snate
28279520Sbapt#define SURFACE3_LID_GUID "F7CC25EC-D20B-404C-8903-0ED4359C18AE"
29279520Sbapt
30275077SbaptMODULE_ALIAS("wmi:" SURFACE3_LID_GUID);
315500Sache
32272787Sngiestatic const struct dmi_system_id surface3_dmi_table[] = {
33272787Sngie#if defined(CONFIG_X86)
34272787Sngie	{
35272787Sngie		.matches = {
3667Snate			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_new = 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);
287