1 /*
2 * Intel Virtual Button driver for Windows 8.1+
3 *
4 * Copyright (C) 2016 AceLan Kao <acelan.kao@canonical.com>
5 * Copyright (C) 2016 Alex Hung <alex.hung@canonical.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 */
18
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/input.h>
23 #include <linux/platform_device.h>
24 #include <linux/input/sparse-keymap.h>
25 #include <linux/acpi.h>
26 #include <acpi/acpi_bus.h>
27
28 MODULE_LICENSE("GPL");
29 MODULE_AUTHOR("AceLan Kao");
30
31 static const struct acpi_device_id intel_vbtn_ids[] = {
32 {"INT33D6", 0},
33 {"", 0},
34 };
35
36 /* In theory, these are HID usages. */
37 static const struct key_entry intel_vbtn_keymap[] = {
38 { KE_IGNORE, 0xC0, { KEY_POWER } }, /* power key press */
39 { KE_KEY, 0xC1, { KEY_POWER } }, /* power key release */
40 { KE_KEY, 0xC4, { KEY_VOLUMEUP } }, /* volume-up key press */
41 { KE_IGNORE, 0xC5, { KEY_VOLUMEUP } }, /* volume-up key release */
42 { KE_KEY, 0xC6, { KEY_VOLUMEDOWN } }, /* volume-down key press */
43 { KE_IGNORE, 0xC7, { KEY_VOLUMEDOWN } }, /* volume-down key release */
44 { KE_END },
45 };
46
47 struct intel_vbtn_priv {
48 struct input_dev *input_dev;
49 };
50
intel_vbtn_input_setup(struct platform_device * device)51 static int intel_vbtn_input_setup(struct platform_device *device)
52 {
53 struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
54 int ret;
55
56 priv->input_dev = input_allocate_device();
57 if (!priv->input_dev)
58 return -ENOMEM;
59
60 ret = sparse_keymap_setup(priv->input_dev, intel_vbtn_keymap, NULL);
61 if (ret)
62 goto err_free_device;
63
64 priv->input_dev->dev.parent = &device->dev;
65 priv->input_dev->name = "Intel Virtual Button driver";
66 priv->input_dev->id.bustype = BUS_HOST;
67
68 ret = input_register_device(priv->input_dev);
69 if (ret)
70 goto err_free_device;
71
72 return 0;
73
74 err_free_device:
75 input_free_device(priv->input_dev);
76 return ret;
77 }
78
intel_vbtn_input_destroy(struct platform_device * device)79 static void intel_vbtn_input_destroy(struct platform_device *device)
80 {
81 struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
82
83 input_unregister_device(priv->input_dev);
84 }
85
notify_handler(acpi_handle handle,u32 event,void * context)86 static void notify_handler(acpi_handle handle, u32 event, void *context)
87 {
88 struct platform_device *device = context;
89 struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
90
91 if (!sparse_keymap_report_event(priv->input_dev, event, 1, true))
92 dev_info(&device->dev, "unknown event index 0x%x\n",
93 event);
94 }
95
intel_vbtn_probe(struct platform_device * device)96 static int intel_vbtn_probe(struct platform_device *device)
97 {
98 acpi_handle handle = ACPI_HANDLE(&device->dev);
99 struct intel_vbtn_priv *priv;
100 acpi_status status;
101 int err;
102
103 status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
104 if (!ACPI_SUCCESS(status)) {
105 dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
106 return -ENODEV;
107 }
108
109 priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
110 if (!priv)
111 return -ENOMEM;
112 dev_set_drvdata(&device->dev, priv);
113
114 err = intel_vbtn_input_setup(device);
115 if (err) {
116 pr_err("Failed to setup Intel Virtual Button\n");
117 return err;
118 }
119
120 status = acpi_install_notify_handler(handle,
121 ACPI_DEVICE_NOTIFY,
122 notify_handler,
123 device);
124 if (ACPI_FAILURE(status)) {
125 err = -EBUSY;
126 goto err_remove_input;
127 }
128
129 return 0;
130
131 err_remove_input:
132 intel_vbtn_input_destroy(device);
133
134 return err;
135 }
136
intel_vbtn_remove(struct platform_device * device)137 static int intel_vbtn_remove(struct platform_device *device)
138 {
139 acpi_handle handle = ACPI_HANDLE(&device->dev);
140
141 intel_vbtn_input_destroy(device);
142 acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
143
144 /*
145 * Even if we failed to shut off the event stream, we can still
146 * safely detach from the device.
147 */
148 return 0;
149 }
150
151 static struct platform_driver intel_vbtn_pl_driver = {
152 .driver = {
153 .name = "intel-vbtn",
154 .acpi_match_table = intel_vbtn_ids,
155 },
156 .probe = intel_vbtn_probe,
157 .remove = intel_vbtn_remove,
158 };
159 MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids);
160
161 static acpi_status __init
check_acpi_dev(acpi_handle handle,u32 lvl,void * context,void ** rv)162 check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
163 {
164 const struct acpi_device_id *ids = context;
165 struct acpi_device *dev;
166
167 if (acpi_bus_get_device(handle, &dev) != 0)
168 return AE_OK;
169
170 if (acpi_match_device_ids(dev, ids) == 0)
171 if (acpi_create_platform_device(dev, NULL))
172 dev_info(&dev->dev,
173 "intel-vbtn: created platform device\n");
174
175 return AE_OK;
176 }
177
intel_vbtn_init(void)178 static int __init intel_vbtn_init(void)
179 {
180 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
181 ACPI_UINT32_MAX, check_acpi_dev, NULL,
182 (void *)intel_vbtn_ids, NULL);
183
184 return platform_driver_register(&intel_vbtn_pl_driver);
185 }
186 module_init(intel_vbtn_init);
187
intel_vbtn_exit(void)188 static void __exit intel_vbtn_exit(void)
189 {
190 platform_driver_unregister(&intel_vbtn_pl_driver);
191 }
192 module_exit(intel_vbtn_exit);
193