tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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
28MODULE_LICENSE("GPL");
29MODULE_AUTHOR("AceLan Kao");
30
31static const struct acpi_device_id intel_vbtn_ids[] = {
32 {"INT33D6", 0},
33 {"", 0},
34};
35
36/* In theory, these are HID usages. */
37static 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_END },
41};
42
43struct intel_vbtn_priv {
44 struct input_dev *input_dev;
45};
46
47static int intel_vbtn_input_setup(struct platform_device *device)
48{
49 struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
50 int ret;
51
52 priv->input_dev = input_allocate_device();
53 if (!priv->input_dev)
54 return -ENOMEM;
55
56 ret = sparse_keymap_setup(priv->input_dev, intel_vbtn_keymap, NULL);
57 if (ret)
58 goto err_free_device;
59
60 priv->input_dev->dev.parent = &device->dev;
61 priv->input_dev->name = "Intel Virtual Button driver";
62 priv->input_dev->id.bustype = BUS_HOST;
63
64 ret = input_register_device(priv->input_dev);
65 if (ret)
66 goto err_free_device;
67
68 return 0;
69
70err_free_device:
71 input_free_device(priv->input_dev);
72 return ret;
73}
74
75static void intel_vbtn_input_destroy(struct platform_device *device)
76{
77 struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
78
79 input_unregister_device(priv->input_dev);
80}
81
82static void notify_handler(acpi_handle handle, u32 event, void *context)
83{
84 struct platform_device *device = context;
85 struct intel_vbtn_priv *priv = dev_get_drvdata(&device->dev);
86
87 if (!sparse_keymap_report_event(priv->input_dev, event, 1, true))
88 dev_info(&device->dev, "unknown event index 0x%x\n",
89 event);
90}
91
92static int intel_vbtn_probe(struct platform_device *device)
93{
94 acpi_handle handle = ACPI_HANDLE(&device->dev);
95 struct intel_vbtn_priv *priv;
96 acpi_status status;
97 int err;
98
99 status = acpi_evaluate_object(handle, "VBDL", NULL, NULL);
100 if (!ACPI_SUCCESS(status)) {
101 dev_warn(&device->dev, "failed to read Intel Virtual Button driver\n");
102 return -ENODEV;
103 }
104
105 priv = devm_kzalloc(&device->dev, sizeof(*priv), GFP_KERNEL);
106 if (!priv)
107 return -ENOMEM;
108 dev_set_drvdata(&device->dev, priv);
109
110 err = intel_vbtn_input_setup(device);
111 if (err) {
112 pr_err("Failed to setup Intel Virtual Button\n");
113 return err;
114 }
115
116 status = acpi_install_notify_handler(handle,
117 ACPI_DEVICE_NOTIFY,
118 notify_handler,
119 device);
120 if (ACPI_FAILURE(status)) {
121 err = -EBUSY;
122 goto err_remove_input;
123 }
124
125 return 0;
126
127err_remove_input:
128 intel_vbtn_input_destroy(device);
129
130 return err;
131}
132
133static int intel_vbtn_remove(struct platform_device *device)
134{
135 acpi_handle handle = ACPI_HANDLE(&device->dev);
136
137 intel_vbtn_input_destroy(device);
138 acpi_remove_notify_handler(handle, ACPI_DEVICE_NOTIFY, notify_handler);
139
140 /*
141 * Even if we failed to shut off the event stream, we can still
142 * safely detach from the device.
143 */
144 return 0;
145}
146
147static struct platform_driver intel_vbtn_pl_driver = {
148 .driver = {
149 .name = "intel-vbtn",
150 .acpi_match_table = intel_vbtn_ids,
151 },
152 .probe = intel_vbtn_probe,
153 .remove = intel_vbtn_remove,
154};
155MODULE_DEVICE_TABLE(acpi, intel_vbtn_ids);
156
157static acpi_status __init
158check_acpi_dev(acpi_handle handle, u32 lvl, void *context, void **rv)
159{
160 const struct acpi_device_id *ids = context;
161 struct acpi_device *dev;
162
163 if (acpi_bus_get_device(handle, &dev) != 0)
164 return AE_OK;
165
166 if (acpi_match_device_ids(dev, ids) == 0)
167 if (acpi_create_platform_device(dev))
168 dev_info(&dev->dev,
169 "intel-vbtn: created platform device\n");
170
171 return AE_OK;
172}
173
174static int __init intel_vbtn_init(void)
175{
176 acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
177 ACPI_UINT32_MAX, check_acpi_dev, NULL,
178 (void *)intel_vbtn_ids, NULL);
179
180 return platform_driver_register(&intel_vbtn_pl_driver);
181}
182module_init(intel_vbtn_init);
183
184static void __exit intel_vbtn_exit(void)
185{
186 platform_driver_unregister(&intel_vbtn_pl_driver);
187}
188module_exit(intel_vbtn_exit);