1 /*
2  * Dell WMI hotkeys
3  *
4  * Copyright (C) 2008 Red Hat <mjg@redhat.com>
5  *
6  * Portions based on wistron_btns.c:
7  * Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
8  * Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
9  * Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
10  *
11  *  This program is free software; you can redistribute it and/or modify
12  *  it under the terms of the GNU General Public License as published by
13  *  the Free Software Foundation; either version 2 of the License, or
14  *  (at your option) any later version.
15  *
16  *  This program is distributed in the hope that it will be useful,
17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  *  GNU General Public License for more details.
20  *
21  *  You should have received a copy of the GNU General Public License
22  *  along with this program; if not, write to the Free Software
23  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
24  */
25 
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <linux/slab.h>
30 #include <linux/types.h>
31 #include <linux/input.h>
32 #include <linux/input/sparse-keymap.h>
33 #include <acpi/acpi_drivers.h>
34 #include <linux/acpi.h>
35 #include <linux/string.h>
36 #include <linux/dmi.h>
37 
38 MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
39 MODULE_DESCRIPTION("Dell laptop WMI hotkeys driver");
40 MODULE_LICENSE("GPL");
41 
42 #define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492"
43 
44 static int acpi_video;
45 
46 MODULE_ALIAS("wmi:"DELL_EVENT_GUID);
47 
48 /*
49  * Certain keys are flagged as KE_IGNORE. All of these are either
50  * notifications (rather than requests for change) or are also sent
51  * via the keyboard controller so should not be sent again.
52  */
53 
54 static const struct key_entry dell_wmi_legacy_keymap[] __initconst = {
55 	{ KE_KEY, 0xe045, { KEY_PROG1 } },
56 	{ KE_KEY, 0xe009, { KEY_EJECTCD } },
57 
58 	/* These also contain the brightness level at offset 6 */
59 	{ KE_KEY, 0xe006, { KEY_BRIGHTNESSUP } },
60 	{ KE_KEY, 0xe005, { KEY_BRIGHTNESSDOWN } },
61 
62 	/* Battery health status button */
63 	{ KE_KEY, 0xe007, { KEY_BATTERY } },
64 
65 	/* This is actually for all radios. Although physically a
66 	 * switch, the notification does not provide an indication of
67 	 * state and so it should be reported as a key */
68 	{ KE_KEY, 0xe008, { KEY_WLAN } },
69 
70 	/* The next device is at offset 6, the active devices are at
71 	   offset 8 and the attached devices at offset 10 */
72 	{ KE_KEY, 0xe00b, { KEY_SWITCHVIDEOMODE } },
73 
74 	{ KE_IGNORE, 0xe00c, { KEY_KBDILLUMTOGGLE } },
75 
76 	/* BIOS error detected */
77 	{ KE_IGNORE, 0xe00d, { KEY_RESERVED } },
78 
79 	/* Wifi Catcher */
80 	{ KE_KEY, 0xe011, {KEY_PROG2 } },
81 
82 	/* Ambient light sensor toggle */
83 	{ KE_IGNORE, 0xe013, { KEY_RESERVED } },
84 
85 	{ KE_IGNORE, 0xe020, { KEY_MUTE } },
86 	{ KE_IGNORE, 0xe02e, { KEY_VOLUMEDOWN } },
87 	{ KE_IGNORE, 0xe030, { KEY_VOLUMEUP } },
88 	{ KE_IGNORE, 0xe033, { KEY_KBDILLUMUP } },
89 	{ KE_IGNORE, 0xe034, { KEY_KBDILLUMDOWN } },
90 	{ KE_IGNORE, 0xe03a, { KEY_CAPSLOCK } },
91 	{ KE_IGNORE, 0xe045, { KEY_NUMLOCK } },
92 	{ KE_IGNORE, 0xe046, { KEY_SCROLLLOCK } },
93 	{ KE_END, 0 }
94 };
95 
96 static bool dell_new_hk_type;
97 
98 struct dell_bios_keymap_entry {
99 	u16 scancode;
100 	u16 keycode;
101 };
102 
103 struct dell_bios_hotkey_table {
104 	struct dmi_header header;
105 	struct dell_bios_keymap_entry keymap[];
106 
107 };
108 
109 static const struct dell_bios_hotkey_table *dell_bios_hotkey_table;
110 
111 static const u16 bios_to_linux_keycode[256] __initconst = {
112 
113 	KEY_MEDIA,	KEY_NEXTSONG,	KEY_PLAYPAUSE, KEY_PREVIOUSSONG,
114 	KEY_STOPCD,	KEY_UNKNOWN,	KEY_UNKNOWN,	KEY_UNKNOWN,
115 	KEY_WWW,	KEY_UNKNOWN,	KEY_VOLUMEDOWN, KEY_MUTE,
116 	KEY_VOLUMEUP,	KEY_UNKNOWN,	KEY_BATTERY,	KEY_EJECTCD,
117 	KEY_UNKNOWN,	KEY_SLEEP,	KEY_PROG1, KEY_BRIGHTNESSDOWN,
118 	KEY_BRIGHTNESSUP,	KEY_UNKNOWN,	KEY_KBDILLUMTOGGLE,
119 	KEY_UNKNOWN,	KEY_SWITCHVIDEOMODE,	KEY_UNKNOWN, KEY_UNKNOWN,
120 	KEY_SWITCHVIDEOMODE,	KEY_UNKNOWN,	KEY_UNKNOWN, KEY_PROG2,
121 	KEY_UNKNOWN, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
122 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
123 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
124 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
125 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
126 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
127 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
128 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
129 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
130 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
131 	KEY_PROG3
132 };
133 
134 static struct input_dev *dell_wmi_input_dev;
135 
dell_wmi_notify(u32 value,void * context)136 static void dell_wmi_notify(u32 value, void *context)
137 {
138 	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
139 	union acpi_object *obj;
140 	acpi_status status;
141 
142 	status = wmi_get_event_data(value, &response);
143 	if (status != AE_OK) {
144 		printk(KERN_INFO "dell-wmi: bad event status 0x%x\n", status);
145 		return;
146 	}
147 
148 	obj = (union acpi_object *)response.pointer;
149 
150 	if (obj && obj->type == ACPI_TYPE_BUFFER) {
151 		const struct key_entry *key;
152 		int reported_key;
153 		u16 *buffer_entry = (u16 *)obj->buffer.pointer;
154 
155 		if (dell_new_hk_type && (buffer_entry[1] != 0x10)) {
156 			printk(KERN_INFO "dell-wmi: Received unknown WMI event"
157 					 " (0x%x)\n", buffer_entry[1]);
158 			kfree(obj);
159 			return;
160 		}
161 
162 		if (dell_new_hk_type || buffer_entry[1] == 0x0)
163 			reported_key = (int)buffer_entry[2];
164 		else
165 			reported_key = (int)buffer_entry[1] & 0xffff;
166 
167 		key = sparse_keymap_entry_from_scancode(dell_wmi_input_dev,
168 							reported_key);
169 		if (!key) {
170 			printk(KERN_INFO "dell-wmi: Unknown key %x pressed\n",
171 				reported_key);
172 		} else if ((key->keycode == KEY_BRIGHTNESSUP ||
173 			    key->keycode == KEY_BRIGHTNESSDOWN) && acpi_video) {
174 			/* Don't report brightness notifications that will also
175 			 * come via ACPI */
176 			;
177 		} else {
178 			sparse_keymap_report_entry(dell_wmi_input_dev, key,
179 						   1, true);
180 		}
181 	}
182 	kfree(obj);
183 }
184 
dell_wmi_prepare_new_keymap(void)185 static const struct key_entry * __init dell_wmi_prepare_new_keymap(void)
186 {
187 	int hotkey_num = (dell_bios_hotkey_table->header.length - 4) /
188 				sizeof(struct dell_bios_keymap_entry);
189 	struct key_entry *keymap;
190 	int i;
191 
192 	keymap = kcalloc(hotkey_num + 1, sizeof(struct key_entry), GFP_KERNEL);
193 	if (!keymap)
194 		return NULL;
195 
196 	for (i = 0; i < hotkey_num; i++) {
197 		const struct dell_bios_keymap_entry *bios_entry =
198 					&dell_bios_hotkey_table->keymap[i];
199 		keymap[i].type = KE_KEY;
200 		keymap[i].code = bios_entry->scancode;
201 		keymap[i].keycode = bios_entry->keycode < 256 ?
202 				    bios_to_linux_keycode[bios_entry->keycode] :
203 				    KEY_RESERVED;
204 	}
205 
206 	keymap[hotkey_num].type = KE_END;
207 
208 	return keymap;
209 }
210 
dell_wmi_input_setup(void)211 static int __init dell_wmi_input_setup(void)
212 {
213 	int err;
214 
215 	dell_wmi_input_dev = input_allocate_device();
216 	if (!dell_wmi_input_dev)
217 		return -ENOMEM;
218 
219 	dell_wmi_input_dev->name = "Dell WMI hotkeys";
220 	dell_wmi_input_dev->phys = "wmi/input0";
221 	dell_wmi_input_dev->id.bustype = BUS_HOST;
222 
223 	if (dell_new_hk_type) {
224 		const struct key_entry *keymap = dell_wmi_prepare_new_keymap();
225 		if (!keymap) {
226 			err = -ENOMEM;
227 			goto err_free_dev;
228 		}
229 
230 		err = sparse_keymap_setup(dell_wmi_input_dev, keymap, NULL);
231 
232 		/*
233 		 * Sparse keymap library makes a copy of keymap so we
234 		 * don't need the original one that was allocated.
235 		 */
236 		kfree(keymap);
237 	} else {
238 		err = sparse_keymap_setup(dell_wmi_input_dev,
239 					  dell_wmi_legacy_keymap, NULL);
240 	}
241 	if (err)
242 		goto err_free_dev;
243 
244 	err = input_register_device(dell_wmi_input_dev);
245 	if (err)
246 		goto err_free_keymap;
247 
248 	return 0;
249 
250  err_free_keymap:
251 	sparse_keymap_free(dell_wmi_input_dev);
252  err_free_dev:
253 	input_free_device(dell_wmi_input_dev);
254 	return err;
255 }
256 
dell_wmi_input_destroy(void)257 static void dell_wmi_input_destroy(void)
258 {
259 	sparse_keymap_free(dell_wmi_input_dev);
260 	input_unregister_device(dell_wmi_input_dev);
261 }
262 
find_hk_type(const struct dmi_header * dm,void * dummy)263 static void __init find_hk_type(const struct dmi_header *dm, void *dummy)
264 {
265 	if (dm->type == 0xb2 && dm->length > 6) {
266 		dell_new_hk_type = true;
267 		dell_bios_hotkey_table =
268 			container_of(dm, struct dell_bios_hotkey_table, header);
269 	}
270 }
271 
dell_wmi_init(void)272 static int __init dell_wmi_init(void)
273 {
274 	int err;
275 	acpi_status status;
276 
277 	if (!wmi_has_guid(DELL_EVENT_GUID)) {
278 		printk(KERN_WARNING "dell-wmi: No known WMI GUID found\n");
279 		return -ENODEV;
280 	}
281 
282 	dmi_walk(find_hk_type, NULL);
283 	acpi_video = acpi_video_backlight_support();
284 
285 	err = dell_wmi_input_setup();
286 	if (err)
287 		return err;
288 
289 	status = wmi_install_notify_handler(DELL_EVENT_GUID,
290 					 dell_wmi_notify, NULL);
291 	if (ACPI_FAILURE(status)) {
292 		dell_wmi_input_destroy();
293 		printk(KERN_ERR
294 			"dell-wmi: Unable to register notify handler - %d\n",
295 			status);
296 		return -ENODEV;
297 	}
298 
299 	return 0;
300 }
301 module_init(dell_wmi_init);
302 
dell_wmi_exit(void)303 static void __exit dell_wmi_exit(void)
304 {
305 	wmi_remove_notify_handler(DELL_EVENT_GUID);
306 	dell_wmi_input_destroy();
307 }
308 module_exit(dell_wmi_exit);
309