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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 27
 28#include <linux/kernel.h>
 29#include <linux/module.h>
 30#include <linux/init.h>
 31#include <linux/slab.h>
 32#include <linux/types.h>
 33#include <linux/input.h>
 34#include <linux/input/sparse-keymap.h>
 35#include <acpi/acpi_drivers.h>
 36#include <linux/acpi.h>
 37#include <linux/string.h>
 38#include <linux/dmi.h>
 39
 40MODULE_AUTHOR("Matthew Garrett <mjg@redhat.com>");
 41MODULE_DESCRIPTION("Dell laptop WMI hotkeys driver");
 42MODULE_LICENSE("GPL");
 43
 44#define DELL_EVENT_GUID "9DBB5994-A997-11DA-B012-B622A1EF5492"
 45
 46static int acpi_video;
 47
 48MODULE_ALIAS("wmi:"DELL_EVENT_GUID);
 49
 50/*
 51 * Certain keys are flagged as KE_IGNORE. All of these are either
 52 * notifications (rather than requests for change) or are also sent
 53 * via the keyboard controller so should not be sent again.
 54 */
 55
 56static const struct key_entry dell_wmi_legacy_keymap[] __initconst = {
 57	{ KE_IGNORE, 0x003a, { KEY_CAPSLOCK } },
 58
 59	{ KE_KEY, 0xe045, { KEY_PROG1 } },
 60	{ KE_KEY, 0xe009, { KEY_EJECTCD } },
 61
 62	/* These also contain the brightness level at offset 6 */
 63	{ KE_KEY, 0xe006, { KEY_BRIGHTNESSUP } },
 64	{ KE_KEY, 0xe005, { KEY_BRIGHTNESSDOWN } },
 65
 66	/* Battery health status button */
 67	{ KE_KEY, 0xe007, { KEY_BATTERY } },
 68
 69	/* This is actually for all radios. Although physically a
 70	 * switch, the notification does not provide an indication of
 71	 * state and so it should be reported as a key */
 72	{ KE_KEY, 0xe008, { KEY_WLAN } },
 73
 74	/* The next device is at offset 6, the active devices are at
 75	   offset 8 and the attached devices at offset 10 */
 76	{ KE_KEY, 0xe00b, { KEY_SWITCHVIDEOMODE } },
 77
 78	{ KE_IGNORE, 0xe00c, { KEY_KBDILLUMTOGGLE } },
 79
 80	/* BIOS error detected */
 81	{ KE_IGNORE, 0xe00d, { KEY_RESERVED } },
 82
 83	/* Wifi Catcher */
 84	{ KE_KEY, 0xe011, {KEY_PROG2 } },
 85
 86	/* Ambient light sensor toggle */
 87	{ KE_IGNORE, 0xe013, { KEY_RESERVED } },
 88
 89	{ KE_IGNORE, 0xe020, { KEY_MUTE } },
 90
 91	/* Shortcut and audio panel keys */
 92	{ KE_IGNORE, 0xe025, { KEY_RESERVED } },
 93	{ KE_IGNORE, 0xe026, { KEY_RESERVED } },
 94
 95	{ KE_IGNORE, 0xe02e, { KEY_VOLUMEDOWN } },
 96	{ KE_IGNORE, 0xe030, { KEY_VOLUMEUP } },
 97	{ KE_IGNORE, 0xe033, { KEY_KBDILLUMUP } },
 98	{ KE_IGNORE, 0xe034, { KEY_KBDILLUMDOWN } },
 99	{ KE_IGNORE, 0xe03a, { KEY_CAPSLOCK } },
100	{ KE_IGNORE, 0xe045, { KEY_NUMLOCK } },
101	{ KE_IGNORE, 0xe046, { KEY_SCROLLLOCK } },
102	{ KE_IGNORE, 0xe0f7, { KEY_MUTE } },
103	{ KE_IGNORE, 0xe0f8, { KEY_VOLUMEDOWN } },
104	{ KE_IGNORE, 0xe0f9, { KEY_VOLUMEUP } },
105	{ KE_END, 0 }
106};
107
108static bool dell_new_hk_type;
109
110struct dell_bios_keymap_entry {
111	u16 scancode;
112	u16 keycode;
113};
114
115struct dell_bios_hotkey_table {
116	struct dmi_header header;
117	struct dell_bios_keymap_entry keymap[];
118
119};
120
121static const struct dell_bios_hotkey_table *dell_bios_hotkey_table;
122
123static const u16 bios_to_linux_keycode[256] __initconst = {
124
125	KEY_MEDIA,	KEY_NEXTSONG,	KEY_PLAYPAUSE, KEY_PREVIOUSSONG,
126	KEY_STOPCD,	KEY_UNKNOWN,	KEY_UNKNOWN,	KEY_UNKNOWN,
127	KEY_WWW,	KEY_UNKNOWN,	KEY_VOLUMEDOWN, KEY_MUTE,
128	KEY_VOLUMEUP,	KEY_UNKNOWN,	KEY_BATTERY,	KEY_EJECTCD,
129	KEY_UNKNOWN,	KEY_SLEEP,	KEY_PROG1, KEY_BRIGHTNESSDOWN,
130	KEY_BRIGHTNESSUP,	KEY_UNKNOWN,	KEY_KBDILLUMTOGGLE,
131	KEY_UNKNOWN,	KEY_SWITCHVIDEOMODE,	KEY_UNKNOWN, KEY_UNKNOWN,
132	KEY_SWITCHVIDEOMODE,	KEY_UNKNOWN,	KEY_UNKNOWN, KEY_PROG2,
133	KEY_UNKNOWN, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
134	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
135	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
136	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
137	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
138	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
139	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
140	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
141	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
142	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
143	KEY_PROG3
144};
145
146static struct input_dev *dell_wmi_input_dev;
147
148static void dell_wmi_notify(u32 value, void *context)
149{
150	struct acpi_buffer response = { ACPI_ALLOCATE_BUFFER, NULL };
151	union acpi_object *obj;
152	acpi_status status;
153
154	status = wmi_get_event_data(value, &response);
155	if (status != AE_OK) {
156		pr_info("bad event status 0x%x\n", status);
157		return;
158	}
159
160	obj = (union acpi_object *)response.pointer;
161
162	if (obj && obj->type == ACPI_TYPE_BUFFER) {
163		const struct key_entry *key;
164		int reported_key;
165		u16 *buffer_entry = (u16 *)obj->buffer.pointer;
166
167		if (dell_new_hk_type && (buffer_entry[1] != 0x10)) {
168			pr_info("Received unknown WMI event (0x%x)\n",
169				buffer_entry[1]);
170			kfree(obj);
171			return;
172		}
173
174		if (dell_new_hk_type || buffer_entry[1] == 0x0)
175			reported_key = (int)buffer_entry[2];
176		else
177			reported_key = (int)buffer_entry[1] & 0xffff;
178
179		key = sparse_keymap_entry_from_scancode(dell_wmi_input_dev,
180							reported_key);
181		if (!key) {
182			pr_info("Unknown key %x pressed\n", reported_key);
183		} else if ((key->keycode == KEY_BRIGHTNESSUP ||
184			    key->keycode == KEY_BRIGHTNESSDOWN) && acpi_video) {
185			/* Don't report brightness notifications that will also
186			 * come via ACPI */
187			;
188		} else {
189			sparse_keymap_report_entry(dell_wmi_input_dev, key,
190						   1, true);
191		}
192	}
193	kfree(obj);
194}
195
196static const struct key_entry * __init dell_wmi_prepare_new_keymap(void)
197{
198	int hotkey_num = (dell_bios_hotkey_table->header.length - 4) /
199				sizeof(struct dell_bios_keymap_entry);
200	struct key_entry *keymap;
201	int i;
202
203	keymap = kcalloc(hotkey_num + 1, sizeof(struct key_entry), GFP_KERNEL);
204	if (!keymap)
205		return NULL;
206
207	for (i = 0; i < hotkey_num; i++) {
208		const struct dell_bios_keymap_entry *bios_entry =
209					&dell_bios_hotkey_table->keymap[i];
210		keymap[i].type = KE_KEY;
211		keymap[i].code = bios_entry->scancode;
212		keymap[i].keycode = bios_entry->keycode < 256 ?
213				    bios_to_linux_keycode[bios_entry->keycode] :
214				    KEY_RESERVED;
215	}
216
217	keymap[hotkey_num].type = KE_END;
218
219	return keymap;
220}
221
222static int __init dell_wmi_input_setup(void)
223{
224	int err;
225
226	dell_wmi_input_dev = input_allocate_device();
227	if (!dell_wmi_input_dev)
228		return -ENOMEM;
229
230	dell_wmi_input_dev->name = "Dell WMI hotkeys";
231	dell_wmi_input_dev->phys = "wmi/input0";
232	dell_wmi_input_dev->id.bustype = BUS_HOST;
233
234	if (dell_new_hk_type) {
235		const struct key_entry *keymap = dell_wmi_prepare_new_keymap();
236		if (!keymap) {
237			err = -ENOMEM;
238			goto err_free_dev;
239		}
240
241		err = sparse_keymap_setup(dell_wmi_input_dev, keymap, NULL);
242
243		/*
244		 * Sparse keymap library makes a copy of keymap so we
245		 * don't need the original one that was allocated.
246		 */
247		kfree(keymap);
248	} else {
249		err = sparse_keymap_setup(dell_wmi_input_dev,
250					  dell_wmi_legacy_keymap, NULL);
251	}
252	if (err)
253		goto err_free_dev;
254
255	err = input_register_device(dell_wmi_input_dev);
256	if (err)
257		goto err_free_keymap;
258
259	return 0;
260
261 err_free_keymap:
262	sparse_keymap_free(dell_wmi_input_dev);
263 err_free_dev:
264	input_free_device(dell_wmi_input_dev);
265	return err;
266}
267
268static void dell_wmi_input_destroy(void)
269{
270	sparse_keymap_free(dell_wmi_input_dev);
271	input_unregister_device(dell_wmi_input_dev);
272}
273
274static void __init find_hk_type(const struct dmi_header *dm, void *dummy)
275{
276	if (dm->type == 0xb2 && dm->length > 6) {
277		dell_new_hk_type = true;
278		dell_bios_hotkey_table =
279			container_of(dm, struct dell_bios_hotkey_table, header);
280	}
281}
282
283static int __init dell_wmi_init(void)
284{
285	int err;
286	acpi_status status;
287
288	if (!wmi_has_guid(DELL_EVENT_GUID)) {
289		pr_warn("No known WMI GUID found\n");
290		return -ENODEV;
291	}
292
293	dmi_walk(find_hk_type, NULL);
294	acpi_video = acpi_video_backlight_support();
295
296	err = dell_wmi_input_setup();
297	if (err)
298		return err;
299
300	status = wmi_install_notify_handler(DELL_EVENT_GUID,
301					 dell_wmi_notify, NULL);
302	if (ACPI_FAILURE(status)) {
303		dell_wmi_input_destroy();
304		pr_err("Unable to register notify handler - %d\n", status);
305		return -ENODEV;
306	}
307
308	return 0;
309}
310module_init(dell_wmi_init);
311
312static void __exit dell_wmi_exit(void)
313{
314	wmi_remove_notify_handler(DELL_EVENT_GUID);
315	dell_wmi_input_destroy();
316}
317module_exit(dell_wmi_exit);