aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/input/sparse-keymap.c
blob: fdb6a3976f94cbfb821aa58841d3075afe08f50f (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
/*
 * Generic support for sparse keymaps
 *
 * Copyright (c) 2009 Dmitry Torokhov
 *
 * Derived from wistron button driver:
 * Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
 * Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
 * Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */

#include <linux/input.h>
#include <linux/input/sparse-keymap.h>
#include <linux/slab.h>

MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
MODULE_DESCRIPTION("Generic support for sparse keymaps");
MODULE_LICENSE("GPL v2");
MODULE_VERSION("0.1");

static unsigned int sparse_keymap_get_key_index(struct input_dev *dev,
						const struct key_entry *k)
{
	struct key_entry *key;
	unsigned int idx = 0;

	for (key = dev->keycode; key->type != KE_END; key++) {
		if (key->type == KE_KEY) {
			if (key == k)
				break;
			idx++;
		}
	}

	return idx;
}

static struct key_entry *sparse_keymap_entry_by_index(struct input_dev *dev,
						      unsigned int index)
{
	struct key_entry *key;
	unsigned int key_cnt = 0;

	for (key = dev->keycode; key->type != KE_END; key++)
		if (key->type == KE_KEY)
			if (key_cnt++ == index)
				return key;

	return NULL;
}

/**
 * sparse_keymap_entry_from_scancode - perform sparse keymap lookup
 * @dev: Input device using sparse keymap
 * @code: Scan code
 *
 * This function is used to perform &struct key_entry lookup in an
 * input device using sparse keymap.
 */
struct key_entry *sparse_keymap_entry_from_scancode(struct input_dev *dev,
						    unsigned int code)
{
	struct key_entry *key;

	for (key = dev->keycode; key->type != KE_END; key++)
		if (code == key->code)
			return key;

	return NULL;
}
EXPORT_SYMBOL(sparse_keymap_entry_from_scancode);

/**
 * sparse_keymap_entry_from_keycode - perform sparse keymap lookup
 * @dev: Input device using sparse keymap
 * @keycode: Key code
 *
 * This function is used to perform &struct key_entry lookup in an
 * input device using sparse keymap.
 */
struct key_entry *sparse_keymap_entry_from_keycode(struct input_dev *dev,
						   unsigned int keycode)
{
	struct key_entry *key;

	for (key = dev->keycode; key->type != KE_END; key++)
		if (key->type == KE_KEY && keycode == key->keycode)
			return key;

	return NULL;
}
EXPORT_SYMBOL(sparse_keymap_entry_from_keycode);

static struct key_entry *sparse_keymap_locate(struct input_dev *dev,
					const struct input_keymap_entry *ke)
{
	struct key_entry *key;
	unsigned int scancode;

	if (ke->flags & INPUT_KEYMAP_BY_INDEX)
		key = sparse_keymap_entry_by_index(dev, ke->index);
	else if (input_scancode_to_scalar(ke, &scancode) == 0)
		key = sparse_keymap_entry_from_scancode(dev, scancode);
	else
		key = NULL;

	return key;
}

static int sparse_keymap_getkeycode(struct input_dev *dev,
				    struct input_keymap_entry *ke)
{
	const struct key_entry *key;

	if (dev->keycode) {
		key = sparse_keymap_locate(dev, ke);
		if (key && key->type == KE_KEY) {
			ke->keycode = key->keycode;
			if (!(ke->flags & INPUT_KEYMAP_BY_INDEX))
				ke->index =
					sparse_keymap_get_key_index(dev, key);
			ke->len = sizeof(key->code);
			memcpy(ke->scancode, &key->code, sizeof(key->code));
			return 0;
		}
	}

	return -EINVAL;
}

static int sparse_keymap_setkeycode(struct input_dev *dev,
				    const struct input_keymap_entry *ke,
				    unsigned int *old_keycode)
{
	struct key_entry *key;

	if (dev->keycode) {
		key = sparse_keymap_locate(dev, ke);
		if (key && key->type == KE_KEY) {
			*old_keycode = key->keycode;
			key->keycode = ke->keycode;
			set_bit(ke->keycode, dev->keybit);
			if (!sparse_keymap_entry_from_keycode(dev, *old_keycode))
				clear_bit(*old_keycode, dev->keybit);
			return 0;
		}
	}

	return -EINVAL;
}

/**
 * sparse_keymap_setup - set up sparse keymap for an input device
 * @dev: Input device
 * @keymap: Keymap in form of array of &key_entry structures ending
 *	with %KE_END type entry
 * @setup: Function that can be used to adjust keymap entries
 *	depending on device's deeds, may be %NULL
 *
 * The function calculates size and allocates copy of the original
 * keymap after which sets up input device event bits appropriately.
 * Before destroying input device allocated keymap should be freed
 * with a call to sparse_keymap_free().
 */
int sparse_keymap_setup(struct input_dev *dev,
			const struct key_entry *keymap,
			int (*setup)(struct input_dev *, struct key_entry *))
{
	size_t map_size = 1; /* to account for the last KE_END entry */
	const struct key_entry *e;
	struct key_entry *map, *entry;
	int i;
	int error;

	for (e = keymap; e->type != KE_END; e++)
		map_size++;

	map = kcalloc(map_size, sizeof (struct key_entry), GFP_KERNEL);
	if (!map)
		return -ENOMEM;

	memcpy(map, keymap, map_size * sizeof (struct key_entry));

	for (i = 0; i < map_size; i++) {
		entry = &map[i];

		if (setup) {
			error = setup(dev, entry);
			if (error)
				goto err_out;
		}

		switch (entry->type) {
		case KE_KEY:
			__set_bit(EV_KEY, dev->evbit);
			__set_bit(entry->keycode, dev->keybit);
			break;

		case KE_SW:
		case KE_VSW:
			__set_bit(EV_SW, dev->evbit);
			__set_bit(entry->sw.code, dev->swbit);
			break;
		}
	}

	if (test_bit(EV_KEY, dev->evbit)) {
		__set_bit(KEY_UNKNOWN, dev->keybit);
		__set_bit(EV_MSC, dev->evbit);
		__set_bit(MSC_SCAN, dev->mscbit);
	}

	dev->keycode = map;
	dev->keycodemax = map_size;
	dev->getkeycode = sparse_keymap_getkeycode;
	dev->setkeycode = sparse_keymap_setkeycode;

	return 0;

 err_out:
	kfree(map);
	return error;
}
EXPORT_SYMBOL(sparse_keymap_setup);

/**
 * sparse_keymap_free - free memory allocated for sparse keymap
 * @dev: Input device using sparse keymap
 *
 * This function is used to free memory allocated by sparse keymap
 * in an input device that was set up by sparse_keymap_setup().
 * NOTE: It is safe to cal this function while input device is
 * still registered (however the drivers should care not to try to
 * use freed keymap and thus have to shut off interrups/polling
 * before freeing the keymap).
 */
void sparse_keymap_free(struct input_dev *dev)
{
	unsigned long flags;

	/*
	 * Take event lock to prevent racing with input_get_keycode()
	 * and input_set_keycode() if we are called while input device
	 * is still registered.
	 */
	spin_lock_irqsave(&dev->event_lock, flags);

	kfree(dev->keycode);
	dev->keycode = NULL;
	dev->keycodemax = 0;

	spin_unlock_irqrestore(&dev->event_lock, flags);
}
EXPORT_SYMBOL(sparse_keymap_free);

/**
 * sparse_keymap_report_entry - report event corresponding to given key entry
 * @dev: Input device for which event should be reported
 * @ke: key entry describing event
 * @value: Value that should be reported (ignored by %KE_SW entries)
 * @autorelease: Signals whether release event should be emitted for %KE_KEY
 *	entries right after reporting press event, ignored by all other
 *	entries
 *
 * This function is used to report input event described by given
 * &struct key_entry.
 */
void sparse_keymap_report_entry(struct input_dev *dev, const struct key_entry *ke,
				unsigned int value, bool autorelease)
{
	switch (ke->type) {
	case KE_KEY:
		input_event(dev, EV_MSC, MSC_SCAN, ke->code);
		input_report_key(dev, ke->keycode, value);
		input_sync(dev);
		if (value && autorelease) {
			input_report_key(dev, ke->keycode, 0);
			input_sync(dev);
		}
		break;

	case KE_SW:
		value = ke->sw.value;
		/* fall through */

	case KE_VSW:
		input_report_switch(dev, ke->sw.code, value);
		break;
	}
}
EXPORT_SYMBOL(sparse_keymap_report_entry);

/**
 * sparse_keymap_report_event - report event corresponding to given scancode
 * @dev: Input device using sparse keymap
 * @code: Scan code
 * @value: Value that should be reported (ignored by %KE_SW entries)
 * @autorelease: Signals whether release event should be emitted for %KE_KEY
 *	entries right after reporting press event, ignored by all other
 *	entries
 *
 * This function is used to perform lookup in an input device using sparse
 * keymap and report corresponding event. Returns %true if lookup was
 * successful and %false otherwise.
 */
bool sparse_keymap_report_event(struct input_dev *dev, unsigned int code,
				unsigned int value, bool autorelease)
{
	const struct key_entry *ke =
		sparse_keymap_entry_from_scancode(dev, code);
	struct key_entry unknown_ke;

	if (ke) {
		sparse_keymap_report_entry(dev, ke, value, autorelease);
		return true;
	}

	/* Report an unknown key event as a debugging aid */
	unknown_ke.type = KE_KEY;
	unknown_ke.code = code;
	unknown_ke.keycode = KEY_UNKNOWN;
	sparse_keymap_report_entry(dev, &unknown_ke, value, true);

	return false;
}
EXPORT_SYMBOL(sparse_keymap_report_event);