xref: /linux/drivers/input/sparse-keymap.c (revision 273b281fa22c293963ee3e6eec418f5dda2dbc83)
1 /*
2  * Generic support for sparse keymaps
3  *
4  * Copyright (c) 2009 Dmitry Torokhov
5  *
6  * Derived from wistron button driver:
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 it
12  * under the terms of the GNU General Public License version 2 as published by
13  * the Free Software Foundation.
14  */
15 
16 #include <linux/input.h>
17 #include <linux/input/sparse-keymap.h>
18 
19 MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
20 MODULE_DESCRIPTION("Generic support for sparse keymaps");
21 MODULE_LICENSE("GPL v2");
22 MODULE_VERSION("0.1");
23 
24 /**
25  * sparse_keymap_entry_from_scancode - perform sparse keymap lookup
26  * @dev: Input device using sparse keymap
27  * @code: Scan code
28  *
29  * This function is used to perform &struct key_entry lookup in an
30  * input device using sparse keymap.
31  */
32 struct key_entry *sparse_keymap_entry_from_scancode(struct input_dev *dev,
33 						    unsigned int code)
34 {
35 	struct key_entry *key;
36 
37 	for (key = dev->keycode; key->type != KE_END; key++)
38 		if (code == key->code)
39 			return key;
40 
41 	return NULL;
42 }
43 EXPORT_SYMBOL(sparse_keymap_entry_from_scancode);
44 
45 /**
46  * sparse_keymap_entry_from_keycode - perform sparse keymap lookup
47  * @dev: Input device using sparse keymap
48  * @keycode: Key code
49  *
50  * This function is used to perform &struct key_entry lookup in an
51  * input device using sparse keymap.
52  */
53 struct key_entry *sparse_keymap_entry_from_keycode(struct input_dev *dev,
54 						   unsigned int keycode)
55 {
56 	struct key_entry *key;
57 
58 	for (key = dev->keycode; key->type != KE_END; key++)
59 		if (key->type == KE_KEY && keycode == key->keycode)
60 			return key;
61 
62 	return NULL;
63 }
64 EXPORT_SYMBOL(sparse_keymap_entry_from_keycode);
65 
66 static int sparse_keymap_getkeycode(struct input_dev *dev,
67 				    int scancode, int *keycode)
68 {
69 	const struct key_entry *key =
70 			sparse_keymap_entry_from_scancode(dev, scancode);
71 
72 	if (key && key->type == KE_KEY) {
73 		*keycode = key->keycode;
74 		return 0;
75 	}
76 
77 	return -EINVAL;
78 }
79 
80 static int sparse_keymap_setkeycode(struct input_dev *dev,
81 				    int scancode, int keycode)
82 {
83 	struct key_entry *key;
84 	int old_keycode;
85 
86 	if (keycode < 0 || keycode > KEY_MAX)
87 		return -EINVAL;
88 
89 	key = sparse_keymap_entry_from_scancode(dev, scancode);
90 	if (key && key->type == KE_KEY) {
91 		old_keycode = key->keycode;
92 		key->keycode = keycode;
93 		set_bit(keycode, dev->keybit);
94 		if (!sparse_keymap_entry_from_keycode(dev, old_keycode))
95 			clear_bit(old_keycode, dev->keybit);
96 		return 0;
97 	}
98 
99 	return -EINVAL;
100 }
101 
102 /**
103  * sparse_keymap_setup - set up sparse keymap for an input device
104  * @dev: Input device
105  * @keymap: Keymap in form of array of &key_entry structures ending
106  *	with %KE_END type entry
107  * @setup: Function that can be used to adjust keymap entries
108  *	depending on device's deeds, may be %NULL
109  *
110  * The function calculates size and allocates copy of the original
111  * keymap after which sets up input device event bits appropriately.
112  * Before destroying input device allocated keymap should be freed
113  * with a call to sparse_keymap_free().
114  */
115 int sparse_keymap_setup(struct input_dev *dev,
116 			const struct key_entry *keymap,
117 			int (*setup)(struct input_dev *, struct key_entry *))
118 {
119 	size_t map_size = 1; /* to account for the last KE_END entry */
120 	const struct key_entry *e;
121 	struct key_entry *map, *entry;
122 	int i;
123 	int error;
124 
125 	for (e = keymap; e->type != KE_END; e++)
126 		map_size++;
127 
128 	map = kcalloc(map_size, sizeof (struct key_entry), GFP_KERNEL);
129 	if (!map)
130 		return -ENOMEM;
131 
132 	memcpy(map, keymap, map_size * sizeof (struct key_entry));
133 
134 	for (i = 0; i < map_size; i++) {
135 		entry = &map[i];
136 
137 		if (setup) {
138 			error = setup(dev, entry);
139 			if (error)
140 				goto err_out;
141 		}
142 
143 		switch (entry->type) {
144 		case KE_KEY:
145 			__set_bit(EV_KEY, dev->evbit);
146 			__set_bit(entry->keycode, dev->keybit);
147 			break;
148 
149 		case KE_SW:
150 			__set_bit(EV_SW, dev->evbit);
151 			__set_bit(entry->sw.code, dev->swbit);
152 			break;
153 		}
154 	}
155 
156 	dev->keycode = map;
157 	dev->keycodemax = map_size;
158 	dev->getkeycode = sparse_keymap_getkeycode;
159 	dev->setkeycode = sparse_keymap_setkeycode;
160 
161 	return 0;
162 
163  err_out:
164 	kfree(keymap);
165 	return error;
166 
167 }
168 EXPORT_SYMBOL(sparse_keymap_setup);
169 
170 /**
171  * sparse_keymap_free - free memory allocated for sparse keymap
172  * @dev: Input device using sparse keymap
173  *
174  * This function is used to free memory allocated by sparse keymap
175  * in an input device that was set up by sparse_keymap_setup().
176  */
177 void sparse_keymap_free(struct input_dev *dev)
178 {
179 	kfree(dev->keycode);
180 	dev->keycode = NULL;
181 	dev->keycodemax = 0;
182 	dev->getkeycode = NULL;
183 	dev->setkeycode = NULL;
184 }
185 EXPORT_SYMBOL(sparse_keymap_free);
186 
187 /**
188  * sparse_keymap_report_entry - report event corresponding to given key entry
189  * @dev: Input device for which event should be reported
190  * @ke: key entry describing event
191  * @value: Value that should be reported (ignored by %KE_SW entries)
192  * @autorelease: Signals whether release event should be emitted for %KE_KEY
193  *	entries right after reporting press event, ignored by all other
194  *	entries
195  *
196  * This function is used to report input event described by given
197  * &struct key_entry.
198  */
199 void sparse_keymap_report_entry(struct input_dev *dev, const struct key_entry *ke,
200 				unsigned int value, bool autorelease)
201 {
202 	switch (ke->type) {
203 	case KE_KEY:
204 		input_report_key(dev, ke->keycode, value);
205 		input_sync(dev);
206 		if (value && autorelease) {
207 			input_report_key(dev, ke->keycode, 0);
208 			input_sync(dev);
209 		}
210 		break;
211 
212 	case KE_SW:
213 		value = ke->sw.value;
214 		/* fall through */
215 
216 	case KE_VSW:
217 		input_report_switch(dev, ke->sw.code, value);
218 		break;
219 	}
220 }
221 EXPORT_SYMBOL(sparse_keymap_report_entry);
222 
223 /**
224  * sparse_keymap_report_event - report event corresponding to given scancode
225  * @dev: Input device using sparse keymap
226  * @code: Scan code
227  * @value: Value that should be reported (ignored by %KE_SW entries)
228  * @autorelease: Signals whether release event should be emitted for %KE_KEY
229  *	entries right after reporting press event, ignored by all other
230  *	entries
231  *
232  * This function is used to perform lookup in an input device using sparse
233  * keymap and report corresponding event. Returns %true if lookup was
234  * successful and %false otherwise.
235  */
236 bool sparse_keymap_report_event(struct input_dev *dev, unsigned int code,
237 				unsigned int value, bool autorelease)
238 {
239 	const struct key_entry *ke =
240 		sparse_keymap_entry_from_scancode(dev, code);
241 
242 	if (ke) {
243 		sparse_keymap_report_entry(dev, ke, value, autorelease);
244 		return true;
245 	}
246 
247 	return false;
248 }
249 EXPORT_SYMBOL(sparse_keymap_report_event);
250 
251