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
21MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
22MODULE_DESCRIPTION("Generic support for sparse keymaps");
23MODULE_LICENSE("GPL v2");
24
25static 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
42static 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 */
64struct 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}
75EXPORT_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 */
85struct 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}
96EXPORT_SYMBOL(sparse_keymap_entry_from_keycode);
97
98static 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
114static 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
135static 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 */
169int 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}
223EXPORT_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 */
237void 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}
261EXPORT_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 */
276bool 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}
296EXPORT_SYMBOL(sparse_keymap_report_event);
297
298