xref: /linux-6.15/drivers/input/sparse-keymap.c (revision 88fcf710)
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 <[email protected]>
8  * Copyright (C) 2005 Bernhard Rosenkraenzer <[email protected]>
9  * Copyright (C) 2005 Dmitry Torokhov <[email protected]>
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 <[email protected]>");
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 				    unsigned int scancode,
68 				    unsigned int *keycode)
69 {
70 	const struct key_entry *key =
71 			sparse_keymap_entry_from_scancode(dev, scancode);
72 
73 	if (key && key->type == KE_KEY) {
74 		*keycode = key->keycode;
75 		return 0;
76 	}
77 
78 	return -EINVAL;
79 }
80 
81 static int sparse_keymap_setkeycode(struct input_dev *dev,
82 				    unsigned int scancode,
83 				    unsigned int keycode)
84 {
85 	struct key_entry *key;
86 	int old_keycode;
87 
88 	if (keycode < 0 || keycode > KEY_MAX)
89 		return -EINVAL;
90 
91 	key = sparse_keymap_entry_from_scancode(dev, scancode);
92 	if (key && key->type == KE_KEY) {
93 		old_keycode = key->keycode;
94 		key->keycode = keycode;
95 		set_bit(keycode, dev->keybit);
96 		if (!sparse_keymap_entry_from_keycode(dev, old_keycode))
97 			clear_bit(old_keycode, dev->keybit);
98 		return 0;
99 	}
100 
101 	return -EINVAL;
102 }
103 
104 /**
105  * sparse_keymap_setup - set up sparse keymap for an input device
106  * @dev: Input device
107  * @keymap: Keymap in form of array of &key_entry structures ending
108  *	with %KE_END type entry
109  * @setup: Function that can be used to adjust keymap entries
110  *	depending on device's deeds, may be %NULL
111  *
112  * The function calculates size and allocates copy of the original
113  * keymap after which sets up input device event bits appropriately.
114  * Before destroying input device allocated keymap should be freed
115  * with a call to sparse_keymap_free().
116  */
117 int sparse_keymap_setup(struct input_dev *dev,
118 			const struct key_entry *keymap,
119 			int (*setup)(struct input_dev *, struct key_entry *))
120 {
121 	size_t map_size = 1; /* to account for the last KE_END entry */
122 	const struct key_entry *e;
123 	struct key_entry *map, *entry;
124 	int i;
125 	int error;
126 
127 	for (e = keymap; e->type != KE_END; e++)
128 		map_size++;
129 
130 	map = kcalloc(map_size, sizeof (struct key_entry), GFP_KERNEL);
131 	if (!map)
132 		return -ENOMEM;
133 
134 	memcpy(map, keymap, map_size * sizeof (struct key_entry));
135 
136 	for (i = 0; i < map_size; i++) {
137 		entry = &map[i];
138 
139 		if (setup) {
140 			error = setup(dev, entry);
141 			if (error)
142 				goto err_out;
143 		}
144 
145 		switch (entry->type) {
146 		case KE_KEY:
147 			__set_bit(EV_KEY, dev->evbit);
148 			__set_bit(entry->keycode, dev->keybit);
149 			break;
150 
151 		case KE_SW:
152 			__set_bit(EV_SW, dev->evbit);
153 			__set_bit(entry->sw.code, dev->swbit);
154 			break;
155 		}
156 	}
157 
158 	dev->keycode = map;
159 	dev->keycodemax = map_size;
160 	dev->getkeycode = sparse_keymap_getkeycode;
161 	dev->setkeycode = sparse_keymap_setkeycode;
162 
163 	return 0;
164 
165  err_out:
166 	kfree(map);
167 	return error;
168 
169 }
170 EXPORT_SYMBOL(sparse_keymap_setup);
171 
172 /**
173  * sparse_keymap_free - free memory allocated for sparse keymap
174  * @dev: Input device using sparse keymap
175  *
176  * This function is used to free memory allocated by sparse keymap
177  * in an input device that was set up by sparse_keymap_setup().
178  */
179 void sparse_keymap_free(struct input_dev *dev)
180 {
181 	kfree(dev->keycode);
182 	dev->keycode = NULL;
183 	dev->keycodemax = 0;
184 	dev->getkeycode = NULL;
185 	dev->setkeycode = NULL;
186 }
187 EXPORT_SYMBOL(sparse_keymap_free);
188 
189 /**
190  * sparse_keymap_report_entry - report event corresponding to given key entry
191  * @dev: Input device for which event should be reported
192  * @ke: key entry describing event
193  * @value: Value that should be reported (ignored by %KE_SW entries)
194  * @autorelease: Signals whether release event should be emitted for %KE_KEY
195  *	entries right after reporting press event, ignored by all other
196  *	entries
197  *
198  * This function is used to report input event described by given
199  * &struct key_entry.
200  */
201 void sparse_keymap_report_entry(struct input_dev *dev, const struct key_entry *ke,
202 				unsigned int value, bool autorelease)
203 {
204 	switch (ke->type) {
205 	case KE_KEY:
206 		input_report_key(dev, ke->keycode, value);
207 		input_sync(dev);
208 		if (value && autorelease) {
209 			input_report_key(dev, ke->keycode, 0);
210 			input_sync(dev);
211 		}
212 		break;
213 
214 	case KE_SW:
215 		value = ke->sw.value;
216 		/* fall through */
217 
218 	case KE_VSW:
219 		input_report_switch(dev, ke->sw.code, value);
220 		break;
221 	}
222 }
223 EXPORT_SYMBOL(sparse_keymap_report_entry);
224 
225 /**
226  * sparse_keymap_report_event - report event corresponding to given scancode
227  * @dev: Input device using sparse keymap
228  * @code: Scan code
229  * @value: Value that should be reported (ignored by %KE_SW entries)
230  * @autorelease: Signals whether release event should be emitted for %KE_KEY
231  *	entries right after reporting press event, ignored by all other
232  *	entries
233  *
234  * This function is used to perform lookup in an input device using sparse
235  * keymap and report corresponding event. Returns %true if lookup was
236  * successful and %false otherwise.
237  */
238 bool sparse_keymap_report_event(struct input_dev *dev, unsigned int code,
239 				unsigned int value, bool autorelease)
240 {
241 	const struct key_entry *ke =
242 		sparse_keymap_entry_from_scancode(dev, code);
243 
244 	if (ke) {
245 		sparse_keymap_report_entry(dev, ke, value, autorelease);
246 		return true;
247 	}
248 
249 	return false;
250 }
251 EXPORT_SYMBOL(sparse_keymap_report_event);
252 
253