1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Intel Virtual Button driver for Windows 8.1+
4 *
5 * Copyright (C) 2016 AceLan Kao <acelan.kao@canonical.com>
6 * Copyright (C) 2016 Alex Hung <alex.hung@canonical.com>
7 */
8
9 #include <linux/acpi.h>
10 #include <linux/dmi.h>
11 #include <linux/input.h>
12 #include <linux/input/sparse-keymap.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/platform_device.h>
16 #include <linux/suspend.h>
17
18 /* When NOT in tablet mode, VGBS returns with the flag 0x40 */
19 #define TABLET_MODE_FLAG 0x40
20 #define DOCK_MODE_FLAG 0x80
21
22 MODULE_LICENSE("GPL");
23 MODULE_AUTHOR("AceLan Kao");
24
25 static const struct acpi_device_id intel_vbtn_ids[] = {
26 {"INT33D6", 0},
27 {"", 0},
28 };
29
30 /* In theory, these are HID usages. */
31 static const struct key_entry intel_vbtn_keymap[] = {
32 { KE_KEY, 0xC0, { KEY_POWER } }, /* power key press */
33 { KE_IGNORE, 0xC1, { KEY_POWER } }, /* power key release */
34 { KE_KEY, 0xC2, { KEY_LEFTMETA } }, /* 'Windows' key press */
35 { KE_KEY, 0xC3, { KEY_LEFTMETA } }, /* 'Windows' key release */
36 { KE_KEY, 0xC4, { KEY_VOLUMEUP } }, /* volume-up key press */
37 { KE_IGNORE, 0xC5, { KEY_VOLUMEUP } }, /* volume-up key release */
38 { KE_KEY, 0xC6, { KEY_VOLUMEDOWN } }, /* volume-down key press */
39 { KE_IGNORE, 0xC7, { KEY_VOLUMEDOWN } }, /* volume-down key release */
40 { KE_KEY, 0xC8, { KEY_ROTATE_LOCK_TOGGLE } }, /* rotate-lock key press */
41 { KE_KEY, 0xC9, { KEY_ROTATE_LOCK_TOGGLE } }, /* rotate-lock key release */
42 { KE_SW, 0xCA, { .sw = { SW_DOCK, 1 } } }, /* Docked */
43 { KE_SW, 0xCB, { .sw = { SW_DOCK, 0 } } }, /* Undocked */
44 { KE_SW, 0xCC, { .sw = { SW_TABLET_MODE, 1 } } }, /* Tablet */
45 { KE_SW, 0xCD, { .sw = { SW_TABLET_MODE, 0 } } }, /* Laptop */
46 { KE_END },
47 };
48
49 struct intel_vbtn_priv {
50 struct input_dev *input_dev;
51 bool wakeup_mode;
52 };
53
intel_vbtn_input_setup(struct platform_device * device)54 static int intel_vbtn_input_setup(struct platform_device *device)
55 {
56 struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
57 int ret;
58
59 priv->input_dev = devm_input_allocate_device(&device->dev);
60 if (!priv->input_dev)
61 return -ENOMEM;
62
63 ret = sparse_keymap_setup(priv->input_dev, intel_vbtn_keymap, NULL);
64 if (ret)
65 return ret;
66
67 priv->input_dev->dev.parent = &device->dev;
68 priv->input_dev->name = "Intel Virtual Button driver";
69 priv->input_dev->id.bustype = BUS_HOST;
70
71 return input_register_device(priv->input_dev);
72 }
73
notify_handler(acpi_handle handle,u32 event,void * context)74 static void notify_handler(acpi_handle handle, u32 event, void *context)
75 {
76 struct platform_device *device = context;
77 struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
78 unsigned int val = !(event & 1); /* Even=press, Odd=release */
79 const struct key_entry *ke, *ke_rel;
80 bool autorelease;
81
82 if (priv->wakeup_mode) {
83 ke = sparse_keymap_entry_from_scancode(priv->input_dev, event);
84 if (ke) {
85 pm_wakeup_hard_event(&device->dev);
86
87 /*
88 * Switch events like tablet mode will wake the device
89 * and report the new switch position to the input
90 * subsystem.
91 */
92 if (ke->type == KE_SW)
93 sparse_keymap_report_event(priv->input_dev,
94 event,
95 val,
96 0);
97 return;
98 }
99 goto out_unknown;
100 }
101
102 /*
103 * Even press events are autorelease if there is no corresponding odd
104 * release event, or if the odd event is KE_IGNORE.
105 */
106 ke_rel = sparse_keymap_entry_from_scancode(priv->input_dev, event | 1);
107 autorelease = val && (!ke_rel || ke_rel->type == KE_IGNORE);
108
109 if (sparse_keymap_report_event(priv->input_dev, event, val, autorelease))
110 return;
111
112 out_unknown:
113 dev_dbg(&device->dev, "unknown event index 0x%x\n", event);
114 }
115
detect_tablet_mode(struct platform_device * device)116 static void detect_tablet_mode(struct platform_device *device)
117 {
118 const char *chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
119 struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
120 acpi_handle handle = ACPI_HANDLE(&device->dev);
121 struct acpi_buffer vgbs_output = { ACPI_ALLOCATE_BUFFER, NULL };
122 union acpi_object *obj;
123 acpi_status status;
124 int m;
125
126 if (!(chassis_type && strcmp(chassis_type, "31") == 0))
127 goto out;
128
129 status = acpi_evaluate_object(handle, "VGBS", NULL, &vgbs_output);
130 if (ACPI_FAILURE(status))
131 goto out;
132
133 obj = vgbs_output.pointer;
134 if (!(obj && obj->type == ACPI_TYPE_INTEGER))
135 goto out;
136
137 m = !(obj->integer.value & TABLET_MODE_FLAG);
138 input_report_switch(priv->input_dev, SW_TABLET_MODE, m);
139 m = (obj->integer.value & DOCK_MODE_FLAG) ? 1 : 0;
140 input_report_switch(priv->input_dev, SW_DOCK, m);
141 out:
142 kfree(vgbs_output.pointer);
143 }
144
intel_vbtn_probe(struct platform_device * device)145 static int intel_vbtn_probe(struct platform_device *device)
146 {
147 acpi_handle handle = ACPI_HANDLE(&device->dev);
148 struct intel_vbtn_priv *priv;
149 acpi_status status;
150 int err;
151
152 status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
153 if (ACPI_FAILURE(status)) {
154 dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
155 return -ENODEV;
156 }
157
158 priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
159 if (!priv)
160 return -ENOMEM;
161 dev_set_drvdata(&device->dev, priv);
162
163 err = intel_vbtn_input_setup(device);
164 if (err) {
165 pr_err("Failed to setup Intel Virtual Button\n");
166 return err;
167 }
168
169 detect_tablet_mode(device);
170
171 status = acpi_install_notify_handler(handle,
172 ACPI_DEVICE_NOTIFY,
173 notify_handler,
174 device);
175 if (ACPI_FAILURE(status))
176 return -EBUSY;
177
178 device_init_wakeup(&device->dev, true);
179 /*
180 * In order for system wakeup to work, the EC GPE has to be marked as
181 * a wakeup one, so do that here (this setting will persist, but it has
182 * no effect until the wakeup mask is set for the EC GPE).
183 */
184 acpi_ec_mark_gpe_for_wake();
185 return 0;
186 }
187
intel_vbtn_remove(struct platform_device * device)188 static int intel_vbtn_remove(struct platform_device *device)
189 {
190 acpi_handle handle = ACPI_HANDLE(&device->dev);
191
192 device_init_wakeup(&device->dev, false);
193 acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
194
195 /*
196 * Even if we failed to shut off the event stream, we can still
197 * safely detach from the device.
198 */
199 return 0;
200 }
201
intel_vbtn_pm_prepare(struct device * dev)202 static int intel_vbtn_pm_prepare(struct device *dev)
203 {
204 if (device_may_wakeup(dev)) {
205 struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
206
207 priv->wakeup_mode = true;
208 }
209 return 0;
210 }
211
intel_vbtn_pm_complete(struct device * dev)212 static void intel_vbtn_pm_complete(struct device *dev)
213 {
214 struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
215
216 priv->wakeup_mode = false;
217 }
218
intel_vbtn_pm_resume(struct device * dev)219 static int intel_vbtn_pm_resume(struct device *dev)
220 {
221 intel_vbtn_pm_complete(dev);
222 return 0;
223 }
224
225 static const struct dev_pm_ops intel_vbtn_pm_ops = {
226 .prepare = intel_vbtn_pm_prepare,
227 .complete = intel_vbtn_pm_complete,
228 .resume = intel_vbtn_pm_resume,
229 .restore = intel_vbtn_pm_resume,
230 .thaw = intel_vbtn_pm_resume,
231 };
232
233 static struct platform_driver intel_vbtn_pl_driver = {
234 .driver = {
235 .name = "intel-vbtn",
236 .acpi_match_table = intel_vbtn_ids,
237 .pm = &intel_vbtn_pm_ops,
238 },
239 .probe = intel_vbtn_probe,
240 .remove = intel_vbtn_remove,
241 };
242 MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids);
243
244 static acpi_status __init
check_acpi_dev(acpi_handle handle,u32 lvl,void * context,void ** rv)245 check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
246 {
247 const struct acpi_device_id *ids = context;
248 struct acpi_device *dev;
249
250 if (acpi_bus_get_device(handle, &dev) != 0)
251 return AE_OK;
252
253 if (acpi_match_device_ids(dev, ids) == 0)
254 if (acpi_create_platform_device(dev, NULL))
255 dev_info(&dev->dev,
256 "intel-vbtn: created platform device\n");
257
258 return AE_OK;
259 }
260
intel_vbtn_init(void)261 static int __init intel_vbtn_init(void)
262 {
263 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
264 ACPI_UINT32_MAX, check_acpi_dev, NULL,
265 (void *)intel_vbtn_ids, NULL);
266
267 return platform_driver_register(&intel_vbtn_pl_driver);
268 }
269 module_init(intel_vbtn_init);
270
intel_vbtn_exit(void)271 static void __exit intel_vbtn_exit(void)
272 {
273 platform_driver_unregister(&intel_vbtn_pl_driver);
274 }
275 module_exit(intel_vbtn_exit);
276
