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_rel;
80 bool autorelease;
81
82 if (priv->wakeup_mode) {
83 if (sparse_keymap_entry_from_scancode(priv->input_dev, event)) {
84 pm_wakeup_hard_event(&device->dev);
85 return;
86 }
87 goto out_unknown;
88 }
89
90 /*
91 * Even press events are autorelease if there is no corresponding odd
92 * release event, or if the odd event is KE_IGNORE.
93 */
94 ke_rel = sparse_keymap_entry_from_scancode(priv->input_dev, event | 1);
95 autorelease = val && (!ke_rel || ke_rel->type == KE_IGNORE);
96
97 if (sparse_keymap_report_event(priv->input_dev, event, val, autorelease))
98 return;
99
100 out_unknown:
101 dev_dbg(&device->dev, "unknown event index 0x%x\n", event);
102 }
103
detect_tablet_mode(struct platform_device * device)104 static void detect_tablet_mode(struct platform_device *device)
105 {
106 const char *chassis_type = dmi_get_system_info(DMI_CHASSIS_TYPE);
107 struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
108 acpi_handle handle = ACPI_HANDLE(&device->dev);
109 struct acpi_buffer vgbs_output = { ACPI_ALLOCATE_BUFFER, NULL };
110 union acpi_object *obj;
111 acpi_status status;
112 int m;
113
114 if (!(chassis_type && strcmp(chassis_type, "31") == 0))
115 goto out;
116
117 status = acpi_evaluate_object(handle, "VGBS", NULL, &vgbs_output);
118 if (ACPI_FAILURE(status))
119 goto out;
120
121 obj = vgbs_output.pointer;
122 if (!(obj && obj->type == ACPI_TYPE_INTEGER))
123 goto out;
124
125 m = !(obj->integer.value & TABLET_MODE_FLAG);
126 input_report_switch(priv->input_dev, SW_TABLET_MODE, m);
127 m = (obj->integer.value & DOCK_MODE_FLAG) ? 1 : 0;
128 input_report_switch(priv->input_dev, SW_DOCK, m);
129 out:
130 kfree(vgbs_output.pointer);
131 }
132
intel_vbtn_probe(struct platform_device * device)133 static int intel_vbtn_probe(struct platform_device *device)
134 {
135 acpi_handle handle = ACPI_HANDLE(&device->dev);
136 struct intel_vbtn_priv *priv;
137 acpi_status status;
138 int err;
139
140 status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
141 if (ACPI_FAILURE(status)) {
142 dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
143 return -ENODEV;
144 }
145
146 priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
147 if (!priv)
148 return -ENOMEM;
149 dev_set_drvdata(&device->dev, priv);
150
151 err = intel_vbtn_input_setup(device);
152 if (err) {
153 pr_err("Failed to setup Intel Virtual Button\n");
154 return err;
155 }
156
157 detect_tablet_mode(device);
158
159 status = acpi_install_notify_handler(handle,
160 ACPI_DEVICE_NOTIFY,
161 notify_handler,
162 device);
163 if (ACPI_FAILURE(status))
164 return -EBUSY;
165
166 device_init_wakeup(&device->dev, true);
167 return 0;
168 }
169
intel_vbtn_remove(struct platform_device * device)170 static int intel_vbtn_remove(struct platform_device *device)
171 {
172 acpi_handle handle = ACPI_HANDLE(&device->dev);
173
174 device_init_wakeup(&device->dev, false);
175 acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
176
177 /*
178 * Even if we failed to shut off the event stream, we can still
179 * safely detach from the device.
180 */
181 return 0;
182 }
183
intel_vbtn_pm_prepare(struct device * dev)184 static int intel_vbtn_pm_prepare(struct device *dev)
185 {
186 struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
187
188 priv->wakeup_mode = true;
189 return 0;
190 }
191
intel_vbtn_pm_resume(struct device * dev)192 static int intel_vbtn_pm_resume(struct device *dev)
193 {
194 struct intel_vbtn_priv *priv = dev_get_drvdata(dev);
195
196 priv->wakeup_mode = false;
197 return 0;
198 }
199
200 static const struct dev_pm_ops intel_vbtn_pm_ops = {
201 .prepare = intel_vbtn_pm_prepare,
202 .resume = intel_vbtn_pm_resume,
203 .restore = intel_vbtn_pm_resume,
204 .thaw = intel_vbtn_pm_resume,
205 };
206
207 static struct platform_driver intel_vbtn_pl_driver = {
208 .driver = {
209 .name = "intel-vbtn",
210 .acpi_match_table = intel_vbtn_ids,
211 .pm = &intel_vbtn_pm_ops,
212 },
213 .probe = intel_vbtn_probe,
214 .remove = intel_vbtn_remove,
215 };
216 MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids);
217
218 static acpi_status __init
check_acpi_dev(acpi_handle handle,u32 lvl,void * context,void ** rv)219 check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
220 {
221 const struct acpi_device_id *ids = context;
222 struct acpi_device *dev;
223
224 if (acpi_bus_get_device(handle, &dev) != 0)
225 return AE_OK;
226
227 if (acpi_match_device_ids(dev, ids) == 0)
228 if (acpi_create_platform_device(dev, NULL))
229 dev_info(&dev->dev,
230 "intel-vbtn: created platform device\n");
231
232 return AE_OK;
233 }
234
intel_vbtn_init(void)235 static int __init intel_vbtn_init(void)
236 {
237 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
238 ACPI_UINT32_MAX, check_acpi_dev, NULL,
239 (void *)intel_vbtn_ids, NULL);
240
241 return platform_driver_register(&intel_vbtn_pl_driver);
242 }
243 module_init(intel_vbtn_init);
244
intel_vbtn_exit(void)245 static void __exit intel_vbtn_exit(void)
246 {
247 platform_driver_unregister(&intel_vbtn_pl_driver);
248 }
249 module_exit(intel_vbtn_exit);
250
