1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* |
3 | * WMI hotkeys support for Dell All-In-One series |
4 | */ |
5 | |
6 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
7 | |
8 | #include <linux/kernel.h> |
9 | #include <linux/module.h> |
10 | #include <linux/init.h> |
11 | #include <linux/types.h> |
12 | #include <linux/input.h> |
13 | #include <linux/input/sparse-keymap.h> |
14 | #include <linux/acpi.h> |
15 | #include <linux/string.h> |
16 | |
17 | MODULE_DESCRIPTION("WMI hotkeys driver for Dell All-In-One series" ); |
18 | MODULE_LICENSE("GPL" ); |
19 | |
20 | #define EVENT_GUID1 "284A0E6B-380E-472A-921F-E52786257FB4" |
21 | #define EVENT_GUID2 "02314822-307C-4F66-BF0E-48AEAEB26CC8" |
22 | |
23 | struct dell_wmi_event { |
24 | u16 length; |
25 | /* 0x000: A hot key pressed or an event occurred |
26 | * 0x00F: A sequence of hot keys are pressed */ |
27 | u16 type; |
28 | u16 event[]; |
29 | }; |
30 | |
31 | static const char *dell_wmi_aio_guids[] = { |
32 | EVENT_GUID1, |
33 | EVENT_GUID2, |
34 | NULL |
35 | }; |
36 | |
37 | MODULE_ALIAS("wmi:" EVENT_GUID1); |
38 | MODULE_ALIAS("wmi:" EVENT_GUID2); |
39 | |
40 | static const struct key_entry dell_wmi_aio_keymap[] = { |
41 | { KE_KEY, 0xc0, { KEY_VOLUMEUP } }, |
42 | { KE_KEY, 0xc1, { KEY_VOLUMEDOWN } }, |
43 | { KE_KEY, 0xe030, { KEY_VOLUMEUP } }, |
44 | { KE_KEY, 0xe02e, { KEY_VOLUMEDOWN } }, |
45 | { KE_KEY, 0xe020, { KEY_MUTE } }, |
46 | { KE_KEY, 0xe027, { KEY_DISPLAYTOGGLE } }, |
47 | { KE_KEY, 0xe006, { KEY_BRIGHTNESSUP } }, |
48 | { KE_KEY, 0xe005, { KEY_BRIGHTNESSDOWN } }, |
49 | { KE_KEY, 0xe00b, { KEY_SWITCHVIDEOMODE } }, |
50 | { KE_END, 0 } |
51 | }; |
52 | |
53 | static struct input_dev *dell_wmi_aio_input_dev; |
54 | |
55 | /* |
56 | * The new WMI event data format will follow the dell_wmi_event structure |
57 | * So, we will check if the buffer matches the format |
58 | */ |
59 | static bool dell_wmi_aio_event_check(u8 *buffer, int length) |
60 | { |
61 | struct dell_wmi_event *event = (struct dell_wmi_event *)buffer; |
62 | |
63 | if (event == NULL || length < 6) |
64 | return false; |
65 | |
66 | if ((event->type == 0 || event->type == 0xf) && |
67 | event->length >= 2) |
68 | return true; |
69 | |
70 | return false; |
71 | } |
72 | |
73 | static void dell_wmi_aio_notify(u32 value, void *context) |
74 | { |
75 | struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL }; |
76 | union acpi_object *obj; |
77 | struct dell_wmi_event *event; |
78 | acpi_status status; |
79 | |
80 | status = wmi_get_event_data(event: value, out: &response); |
81 | if (status != AE_OK) { |
82 | pr_info("bad event status 0x%x\n" , status); |
83 | return; |
84 | } |
85 | |
86 | obj = (union acpi_object *)response.pointer; |
87 | if (obj) { |
88 | unsigned int scancode = 0; |
89 | |
90 | switch (obj->type) { |
91 | case ACPI_TYPE_INTEGER: |
92 | /* Most All-In-One correctly return integer scancode */ |
93 | scancode = obj->integer.value; |
94 | sparse_keymap_report_event(dev: dell_wmi_aio_input_dev, |
95 | code: scancode, value: 1, autorelease: true); |
96 | break; |
97 | case ACPI_TYPE_BUFFER: |
98 | if (dell_wmi_aio_event_check(buffer: obj->buffer.pointer, |
99 | length: obj->buffer.length)) { |
100 | event = (struct dell_wmi_event *) |
101 | obj->buffer.pointer; |
102 | scancode = event->event[0]; |
103 | } else { |
104 | /* Broken machines return the scancode in a |
105 | buffer */ |
106 | if (obj->buffer.pointer && |
107 | obj->buffer.length > 0) |
108 | scancode = obj->buffer.pointer[0]; |
109 | } |
110 | if (scancode) |
111 | sparse_keymap_report_event( |
112 | dev: dell_wmi_aio_input_dev, |
113 | code: scancode, value: 1, autorelease: true); |
114 | break; |
115 | } |
116 | } |
117 | kfree(objp: obj); |
118 | } |
119 | |
120 | static int __init dell_wmi_aio_input_setup(void) |
121 | { |
122 | int err; |
123 | |
124 | dell_wmi_aio_input_dev = input_allocate_device(); |
125 | |
126 | if (!dell_wmi_aio_input_dev) |
127 | return -ENOMEM; |
128 | |
129 | dell_wmi_aio_input_dev->name = "Dell AIO WMI hotkeys" ; |
130 | dell_wmi_aio_input_dev->phys = "wmi/input0" ; |
131 | dell_wmi_aio_input_dev->id.bustype = BUS_HOST; |
132 | |
133 | err = sparse_keymap_setup(dev: dell_wmi_aio_input_dev, |
134 | keymap: dell_wmi_aio_keymap, NULL); |
135 | if (err) { |
136 | pr_err("Unable to setup input device keymap\n" ); |
137 | goto err_free_dev; |
138 | } |
139 | err = input_register_device(dell_wmi_aio_input_dev); |
140 | if (err) { |
141 | pr_info("Unable to register input device\n" ); |
142 | goto err_free_dev; |
143 | } |
144 | return 0; |
145 | |
146 | err_free_dev: |
147 | input_free_device(dev: dell_wmi_aio_input_dev); |
148 | return err; |
149 | } |
150 | |
151 | static const char *dell_wmi_aio_find(void) |
152 | { |
153 | int i; |
154 | |
155 | for (i = 0; dell_wmi_aio_guids[i] != NULL; i++) |
156 | if (wmi_has_guid(guid: dell_wmi_aio_guids[i])) |
157 | return dell_wmi_aio_guids[i]; |
158 | |
159 | return NULL; |
160 | } |
161 | |
162 | static int __init dell_wmi_aio_init(void) |
163 | { |
164 | int err; |
165 | const char *guid; |
166 | |
167 | guid = dell_wmi_aio_find(); |
168 | if (!guid) { |
169 | pr_warn("No known WMI GUID found\n" ); |
170 | return -ENXIO; |
171 | } |
172 | |
173 | err = dell_wmi_aio_input_setup(); |
174 | if (err) |
175 | return err; |
176 | |
177 | err = wmi_install_notify_handler(guid, handler: dell_wmi_aio_notify, NULL); |
178 | if (err) { |
179 | pr_err("Unable to register notify handler - %d\n" , err); |
180 | input_unregister_device(dell_wmi_aio_input_dev); |
181 | return err; |
182 | } |
183 | |
184 | return 0; |
185 | } |
186 | |
187 | static void __exit dell_wmi_aio_exit(void) |
188 | { |
189 | const char *guid; |
190 | |
191 | guid = dell_wmi_aio_find(); |
192 | wmi_remove_notify_handler(guid); |
193 | input_unregister_device(dell_wmi_aio_input_dev); |
194 | } |
195 | |
196 | module_init(dell_wmi_aio_init); |
197 | module_exit(dell_wmi_aio_exit); |
198 | |