1 /*
2 * WMI hotkeys support for Dell All-In-One series
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 */
18
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
20
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/init.h>
24 #include <linux/types.h>
25 #include <linux/input.h>
26 #include <linux/input/sparse-keymap.h>
27 #include <linux/acpi.h>
28 #include <linux/string.h>
29
30 MODULE_DESCRIPTION("WMI hotkeys driver for Dell All-In-One series");
31 MODULE_LICENSE("GPL");
32
33 #define EVENT_GUID1 "284A0E6B-380E-472A-921F-E52786257FB4"
34 #define EVENT_GUID2 "02314822-307C-4F66-BF0E-48AEAEB26CC8"
35
36 struct dell_wmi_event {
37 u16 length;
38 /* 0x000: A hot key pressed or an event occurred
39 * 0x00F: A sequence of hot keys are pressed */
40 u16 type;
41 u16 event[];
42 };
43
44 static const char *dell_wmi_aio_guids[] = {
45 EVENT_GUID1,
46 EVENT_GUID2,
47 NULL
48 };
49
50 MODULE_ALIAS("wmi:"EVENT_GUID1);
51 MODULE_ALIAS("wmi:"EVENT_GUID2);
52
53 static const struct key_entry dell_wmi_aio_keymap[] = {
54 { KE_KEY, 0xc0, { KEY_VOLUMEUP } },
55 { KE_KEY, 0xc1, { KEY_VOLUMEDOWN } },
56 { KE_KEY, 0xe030, { KEY_VOLUMEUP } },
57 { KE_KEY, 0xe02e, { KEY_VOLUMEDOWN } },
58 { KE_KEY, 0xe020, { KEY_MUTE } },
59 { KE_KEY, 0xe027, { KEY_DISPLAYTOGGLE } },
60 { KE_KEY, 0xe006, { KEY_BRIGHTNESSUP } },
61 { KE_KEY, 0xe005, { KEY_BRIGHTNESSDOWN } },
62 { KE_KEY, 0xe00b, { KEY_SWITCHVIDEOMODE } },
63 { KE_END, 0 }
64 };
65
66 static struct input_dev *dell_wmi_aio_input_dev;
67
68 /*
69 * The new WMI event data format will follow the dell_wmi_event structure
70 * So, we will check if the buffer matches the format
71 */
dell_wmi_aio_event_check(u8 * buffer,int length)72 static bool dell_wmi_aio_event_check(u8 *buffer, int length)
73 {
74 struct dell_wmi_event *event = (struct dell_wmi_event *)buffer;
75
76 if (event == NULL || length < 6)
77 return false;
78
79 if ((event->type == 0 || event->type == 0xf) &&
80 event->length >= 2)
81 return true;
82
83 return false;
84 }
85
dell_wmi_aio_notify(u32 value,void * context)86 static void dell_wmi_aio_notify(u32 value, void *context)
87 {
88 struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
89 union acpi_object *obj;
90 struct dell_wmi_event *event;
91 acpi_status status;
92
93 status = wmi_get_event_data(value, &response);
94 if (status != AE_OK) {
95 pr_info("bad event status 0x%x\n", status);
96 return;
97 }
98
99 obj = (union acpi_object *)response.pointer;
100 if (obj) {
101 unsigned int scancode = 0;
102
103 switch (obj->type) {
104 case ACPI_TYPE_INTEGER:
105 /* Most All-In-One correctly return integer scancode */
106 scancode = obj->integer.value;
107 sparse_keymap_report_event(dell_wmi_aio_input_dev,
108 scancode, 1, true);
109 break;
110 case ACPI_TYPE_BUFFER:
111 if (dell_wmi_aio_event_check(obj->buffer.pointer,
112 obj->buffer.length)) {
113 event = (struct dell_wmi_event *)
114 obj->buffer.pointer;
115 scancode = event->event[0];
116 } else {
117 /* Broken machines return the scancode in a
118 buffer */
119 if (obj->buffer.pointer &&
120 obj->buffer.length > 0)
121 scancode = obj->buffer.pointer[0];
122 }
123 if (scancode)
124 sparse_keymap_report_event(
125 dell_wmi_aio_input_dev,
126 scancode, 1, true);
127 break;
128 }
129 }
130 kfree(obj);
131 }
132
dell_wmi_aio_input_setup(void)133 static int __init dell_wmi_aio_input_setup(void)
134 {
135 int err;
136
137 dell_wmi_aio_input_dev = input_allocate_device();
138
139 if (!dell_wmi_aio_input_dev)
140 return -ENOMEM;
141
142 dell_wmi_aio_input_dev->name = "Dell AIO WMI hotkeys";
143 dell_wmi_aio_input_dev->phys = "wmi/input0";
144 dell_wmi_aio_input_dev->id.bustype = BUS_HOST;
145
146 err = sparse_keymap_setup(dell_wmi_aio_input_dev,
147 dell_wmi_aio_keymap, NULL);
148 if (err) {
149 pr_err("Unable to setup input device keymap\n");
150 goto err_free_dev;
151 }
152 err = input_register_device(dell_wmi_aio_input_dev);
153 if (err) {
154 pr_info("Unable to register input device\n");
155 goto err_free_keymap;
156 }
157 return 0;
158
159 err_free_keymap:
160 sparse_keymap_free(dell_wmi_aio_input_dev);
161 err_free_dev:
162 input_free_device(dell_wmi_aio_input_dev);
163 return err;
164 }
165
dell_wmi_aio_find(void)166 static const char *dell_wmi_aio_find(void)
167 {
168 int i;
169
170 for (i = 0; dell_wmi_aio_guids[i] != NULL; i++)
171 if (wmi_has_guid(dell_wmi_aio_guids[i]))
172 return dell_wmi_aio_guids[i];
173
174 return NULL;
175 }
176
dell_wmi_aio_init(void)177 static int __init dell_wmi_aio_init(void)
178 {
179 int err;
180 const char *guid;
181
182 guid = dell_wmi_aio_find();
183 if (!guid) {
184 pr_warn("No known WMI GUID found\n");
185 return -ENXIO;
186 }
187
188 err = dell_wmi_aio_input_setup();
189 if (err)
190 return err;
191
192 err = wmi_install_notify_handler(guid, dell_wmi_aio_notify, NULL);
193 if (err) {
194 pr_err("Unable to register notify handler - %d\n", err);
195 sparse_keymap_free(dell_wmi_aio_input_dev);
196 input_unregister_device(dell_wmi_aio_input_dev);
197 return err;
198 }
199
200 return 0;
201 }
202
dell_wmi_aio_exit(void)203 static void __exit dell_wmi_aio_exit(void)
204 {
205 const char *guid;
206
207 guid = dell_wmi_aio_find();
208 wmi_remove_notify_handler(guid);
209 sparse_keymap_free(dell_wmi_aio_input_dev);
210 input_unregister_device(dell_wmi_aio_input_dev);
211 }
212
213 module_init(dell_wmi_aio_init);
214 module_exit(dell_wmi_aio_exit);
215