xref: /openbmc/linux/drivers/input/sparse-keymap.c (revision 82e6fdd6)
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 #include <linux/module.h>
19 #include <linux/slab.h>
20 
21 MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
22 MODULE_DESCRIPTION("Generic support for sparse keymaps");
23 MODULE_LICENSE("GPL v2");
24 
25 static unsigned int sparse_keymap_get_key_index(struct input_dev *dev,
26 						const struct key_entry *k)
27 {
28 	struct key_entry *key;
29 	unsigned int idx = 0;
30 
31 	for (key = dev->keycode; key->type != KE_END; key++) {
32 		if (key->type == KE_KEY) {
33 			if (key == k)
34 				break;
35 			idx++;
36 		}
37 	}
38 
39 	return idx;
40 }
41 
42 static struct key_entry *sparse_keymap_entry_by_index(struct input_dev *dev,
43 						      unsigned int index)
44 {
45 	struct key_entry *key;
46 	unsigned int key_cnt = 0;
47 
48 	for (key = dev->keycode; key->type != KE_END; key++)
49 		if (key->type == KE_KEY)
50 			if (key_cnt++ == index)
51 				return key;
52 
53 	return NULL;
54 }
55 
56 /**
57  * sparse_keymap_entry_from_scancode - perform sparse keymap lookup
58  * @dev: Input device using sparse keymap
59  * @code: Scan code
60  *
61  * This function is used to perform &struct key_entry lookup in an
62  * input device using sparse keymap.
63  */
64 struct key_entry *sparse_keymap_entry_from_scancode(struct input_dev *dev,
65 						    unsigned int code)
66 {
67 	struct key_entry *key;
68 
69 	for (key = dev->keycode; key->type != KE_END; key++)
70 		if (code == key->code)
71 			return key;
72 
73 	return NULL;
74 }
75 EXPORT_SYMBOL(sparse_keymap_entry_from_scancode);
76 
77 /**
78  * sparse_keymap_entry_from_keycode - perform sparse keymap lookup
79  * @dev: Input device using sparse keymap
80  * @keycode: Key code
81  *
82  * This function is used to perform &struct key_entry lookup in an
83  * input device using sparse keymap.
84  */
85 struct key_entry *sparse_keymap_entry_from_keycode(struct input_dev *dev,
86 						   unsigned int keycode)
87 {
88 	struct key_entry *key;
89 
90 	for (key = dev->keycode; key->type != KE_END; key++)
91 		if (key->type == KE_KEY && keycode == key->keycode)
92 			return key;
93 
94 	return NULL;
95 }
96 EXPORT_SYMBOL(sparse_keymap_entry_from_keycode);
97 
98 static struct key_entry *sparse_keymap_locate(struct input_dev *dev,
99 					const struct input_keymap_entry *ke)
100 {
101 	struct key_entry *key;
102 	unsigned int scancode;
103 
104 	if (ke->flags & INPUT_KEYMAP_BY_INDEX)
105 		key = sparse_keymap_entry_by_index(dev, ke->index);
106 	else if (input_scancode_to_scalar(ke, &scancode) == 0)
107 		key = sparse_keymap_entry_from_scancode(dev, scancode);
108 	else
109 		key = NULL;
110 
111 	return key;
112 }
113 
114 static int sparse_keymap_getkeycode(struct input_dev *dev,
115 				    struct input_keymap_entry *ke)
116 {
117 	const struct key_entry *key;
118 
119 	if (dev->keycode) {
120 		key = sparse_keymap_locate(dev, ke);
121 		if (key && key->type == KE_KEY) {
122 			ke->keycode = key->keycode;
123 			if (!(ke->flags & INPUT_KEYMAP_BY_INDEX))
124 				ke->index =
125 					sparse_keymap_get_key_index(dev, key);
126 			ke->len = sizeof(key->code);
127 			memcpy(ke->scancode, &key->code, sizeof(key->code));
128 			return 0;
129 		}
130 	}
131 
132 	return -EINVAL;
133 }
134 
135 static int sparse_keymap_setkeycode(struct input_dev *dev,
136 				    const struct input_keymap_entry *ke,
137 				    unsigned int *old_keycode)
138 {
139 	struct key_entry *key;
140 
141 	if (dev->keycode) {
142 		key = sparse_keymap_locate(dev, ke);
143 		if (key && key->type == KE_KEY) {
144 			*old_keycode = key->keycode;
145 			key->keycode = ke->keycode;
146 			set_bit(ke->keycode, dev->keybit);
147 			if (!sparse_keymap_entry_from_keycode(dev, *old_keycode))
148 				clear_bit(*old_keycode, dev->keybit);
149 			return 0;
150 		}
151 	}
152 
153 	return -EINVAL;
154 }
155 
156 /**
157  * sparse_keymap_setup - set up sparse keymap for an input device
158  * @dev: Input device
159  * @keymap: Keymap in form of array of &key_entry structures ending
160  *	with %KE_END type entry
161  * @setup: Function that can be used to adjust keymap entries
162  *	depending on device's needs, may be %NULL
163  *
164  * The function calculates size and allocates copy of the original
165  * keymap after which sets up input device event bits appropriately.
166  * The allocated copy of the keymap is automatically freed when it
167  * is no longer needed.
168  */
169 int sparse_keymap_setup(struct input_dev *dev,
170 			const struct key_entry *keymap,
171 			int (*setup)(struct input_dev *, struct key_entry *))
172 {
173 	size_t map_size = 1; /* to account for the last KE_END entry */
174 	const struct key_entry *e;
175 	struct key_entry *map, *entry;
176 	int i;
177 	int error;
178 
179 	for (e = keymap; e->type != KE_END; e++)
180 		map_size++;
181 
182 	map = devm_kmemdup(&dev->dev, keymap, map_size * sizeof(*map),
183 			   GFP_KERNEL);
184 	if (!map)
185 		return -ENOMEM;
186 
187 	for (i = 0; i < map_size; i++) {
188 		entry = &map[i];
189 
190 		if (setup) {
191 			error = setup(dev, entry);
192 			if (error)
193 				return error;
194 		}
195 
196 		switch (entry->type) {
197 		case KE_KEY:
198 			__set_bit(EV_KEY, dev->evbit);
199 			__set_bit(entry->keycode, dev->keybit);
200 			break;
201 
202 		case KE_SW:
203 		case KE_VSW:
204 			__set_bit(EV_SW, dev->evbit);
205 			__set_bit(entry->sw.code, dev->swbit);
206 			break;
207 		}
208 	}
209 
210 	if (test_bit(EV_KEY, dev->evbit)) {
211 		__set_bit(KEY_UNKNOWN, dev->keybit);
212 		__set_bit(EV_MSC, dev->evbit);
213 		__set_bit(MSC_SCAN, dev->mscbit);
214 	}
215 
216 	dev->keycode = map;
217 	dev->keycodemax = map_size;
218 	dev->getkeycode = sparse_keymap_getkeycode;
219 	dev->setkeycode = sparse_keymap_setkeycode;
220 
221 	return 0;
222 }
223 EXPORT_SYMBOL(sparse_keymap_setup);
224 
225 /**
226  * sparse_keymap_report_entry - report event corresponding to given key entry
227  * @dev: Input device for which event should be reported
228  * @ke: key entry describing event
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 report input event described by given
235  * &struct key_entry.
236  */
237 void sparse_keymap_report_entry(struct input_dev *dev, const struct key_entry *ke,
238 				unsigned int value, bool autorelease)
239 {
240 	switch (ke->type) {
241 	case KE_KEY:
242 		input_event(dev, EV_MSC, MSC_SCAN, ke->code);
243 		input_report_key(dev, ke->keycode, value);
244 		input_sync(dev);
245 		if (value && autorelease) {
246 			input_report_key(dev, ke->keycode, 0);
247 			input_sync(dev);
248 		}
249 		break;
250 
251 	case KE_SW:
252 		value = ke->sw.value;
253 		/* fall through */
254 
255 	case KE_VSW:
256 		input_report_switch(dev, ke->sw.code, value);
257 		input_sync(dev);
258 		break;
259 	}
260 }
261 EXPORT_SYMBOL(sparse_keymap_report_entry);
262 
263 /**
264  * sparse_keymap_report_event - report event corresponding to given scancode
265  * @dev: Input device using sparse keymap
266  * @code: Scan code
267  * @value: Value that should be reported (ignored by %KE_SW entries)
268  * @autorelease: Signals whether release event should be emitted for %KE_KEY
269  *	entries right after reporting press event, ignored by all other
270  *	entries
271  *
272  * This function is used to perform lookup in an input device using sparse
273  * keymap and report corresponding event. Returns %true if lookup was
274  * successful and %false otherwise.
275  */
276 bool sparse_keymap_report_event(struct input_dev *dev, unsigned int code,
277 				unsigned int value, bool autorelease)
278 {
279 	const struct key_entry *ke =
280 		sparse_keymap_entry_from_scancode(dev, code);
281 	struct key_entry unknown_ke;
282 
283 	if (ke) {
284 		sparse_keymap_report_entry(dev, ke, value, autorelease);
285 		return true;
286 	}
287 
288 	/* Report an unknown key event as a debugging aid */
289 	unknown_ke.type = KE_KEY;
290 	unknown_ke.code = code;
291 	unknown_ke.keycode = KEY_UNKNOWN;
292 	sparse_keymap_report_entry(dev, &unknown_ke, value, true);
293 
294 	return false;
295 }
296 EXPORT_SYMBOL(sparse_keymap_report_event);
297 
298