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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Generic support for sparse keymaps
4 *
5 * Copyright (c) 2009 Dmitry Torokhov
6 *
7 * Derived from wistron button driver:
8 * Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
9 * Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
10 * Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
11 */
12
13#include <linux/input.h>
14#include <linux/input/sparse-keymap.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17
18MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
19MODULE_DESCRIPTION("Generic support for sparse keymaps");
20MODULE_LICENSE("GPL v2");
21
22static unsigned int sparse_keymap_get_key_index(struct input_dev *dev,
23 const struct key_entry *k)
24{
25 struct key_entry *key;
26 unsigned int idx = 0;
27
28 for (key = dev->keycode; key->type != KE_END; key++) {
29 if (key->type == KE_KEY) {
30 if (key == k)
31 break;
32 idx++;
33 }
34 }
35
36 return idx;
37}
38
39static struct key_entry *sparse_keymap_entry_by_index(struct input_dev *dev,
40 unsigned int index)
41{
42 struct key_entry *key;
43 unsigned int key_cnt = 0;
44
45 for (key = dev->keycode; key->type != KE_END; key++)
46 if (key->type == KE_KEY)
47 if (key_cnt++ == index)
48 return key;
49
50 return NULL;
51}
52
53/**
54 * sparse_keymap_entry_from_scancode - perform sparse keymap lookup
55 * @dev: Input device using sparse keymap
56 * @code: Scan code
57 *
58 * This function is used to perform &struct key_entry lookup in an
59 * input device using sparse keymap.
60 */
61struct key_entry *sparse_keymap_entry_from_scancode(struct input_dev *dev,
62 unsigned int code)
63{
64 struct key_entry *key;
65
66 for (key = dev->keycode; key->type != KE_END; key++)
67 if (code == key->code)
68 return key;
69
70 return NULL;
71}
72EXPORT_SYMBOL(sparse_keymap_entry_from_scancode);
73
74/**
75 * sparse_keymap_entry_from_keycode - perform sparse keymap lookup
76 * @dev: Input device using sparse keymap
77 * @keycode: Key code
78 *
79 * This function is used to perform &struct key_entry lookup in an
80 * input device using sparse keymap.
81 */
82struct key_entry *sparse_keymap_entry_from_keycode(struct input_dev *dev,
83 unsigned int keycode)
84{
85 struct key_entry *key;
86
87 for (key = dev->keycode; key->type != KE_END; key++)
88 if (key->type == KE_KEY && keycode == key->keycode)
89 return key;
90
91 return NULL;
92}
93EXPORT_SYMBOL(sparse_keymap_entry_from_keycode);
94
95static struct key_entry *sparse_keymap_locate(struct input_dev *dev,
96 const struct input_keymap_entry *ke)
97{
98 struct key_entry *key;
99 unsigned int scancode;
100
101 if (ke->flags & INPUT_KEYMAP_BY_INDEX)
102 key = sparse_keymap_entry_by_index(dev, ke->index);
103 else if (input_scancode_to_scalar(ke, &scancode) == 0)
104 key = sparse_keymap_entry_from_scancode(dev, scancode);
105 else
106 key = NULL;
107
108 return key;
109}
110
111static int sparse_keymap_getkeycode(struct input_dev *dev,
112 struct input_keymap_entry *ke)
113{
114 const struct key_entry *key;
115
116 if (dev->keycode) {
117 key = sparse_keymap_locate(dev, ke);
118 if (key && key->type == KE_KEY) {
119 ke->keycode = key->keycode;
120 if (!(ke->flags & INPUT_KEYMAP_BY_INDEX))
121 ke->index =
122 sparse_keymap_get_key_index(dev, key);
123 ke->len = sizeof(key->code);
124 memcpy(ke->scancode, &key->code, sizeof(key->code));
125 return 0;
126 }
127 }
128
129 return -EINVAL;
130}
131
132static int sparse_keymap_setkeycode(struct input_dev *dev,
133 const struct input_keymap_entry *ke,
134 unsigned int *old_keycode)
135{
136 struct key_entry *key;
137
138 if (dev->keycode) {
139 key = sparse_keymap_locate(dev, ke);
140 if (key && key->type == KE_KEY) {
141 *old_keycode = key->keycode;
142 key->keycode = ke->keycode;
143 set_bit(ke->keycode, dev->keybit);
144 if (!sparse_keymap_entry_from_keycode(dev, *old_keycode))
145 clear_bit(*old_keycode, dev->keybit);
146 return 0;
147 }
148 }
149
150 return -EINVAL;
151}
152
153/**
154 * sparse_keymap_setup - set up sparse keymap for an input device
155 * @dev: Input device
156 * @keymap: Keymap in form of array of &key_entry structures ending
157 * with %KE_END type entry
158 * @setup: Function that can be used to adjust keymap entries
159 * depending on device's needs, may be %NULL
160 *
161 * The function calculates size and allocates copy of the original
162 * keymap after which sets up input device event bits appropriately.
163 * The allocated copy of the keymap is automatically freed when it
164 * is no longer needed.
165 */
166int sparse_keymap_setup(struct input_dev *dev,
167 const struct key_entry *keymap,
168 int (*setup)(struct input_dev *, struct key_entry *))
169{
170 size_t map_size = 1; /* to account for the last KE_END entry */
171 const struct key_entry *e;
172 struct key_entry *map, *entry;
173 int i;
174 int error;
175
176 for (e = keymap; e->type != KE_END; e++)
177 map_size++;
178
179 map = devm_kmemdup(&dev->dev, keymap, map_size * sizeof(*map),
180 GFP_KERNEL);
181 if (!map)
182 return -ENOMEM;
183
184 for (i = 0; i < map_size; i++) {
185 entry = &map[i];
186
187 if (setup) {
188 error = setup(dev, entry);
189 if (error)
190 return error;
191 }
192
193 switch (entry->type) {
194 case KE_KEY:
195 __set_bit(EV_KEY, dev->evbit);
196 __set_bit(entry->keycode, dev->keybit);
197 break;
198
199 case KE_SW:
200 case KE_VSW:
201 __set_bit(EV_SW, dev->evbit);
202 __set_bit(entry->sw.code, dev->swbit);
203 break;
204 }
205 }
206
207 if (test_bit(EV_KEY, dev->evbit)) {
208 __set_bit(KEY_UNKNOWN, dev->keybit);
209 __set_bit(EV_MSC, dev->evbit);
210 __set_bit(MSC_SCAN, dev->mscbit);
211 }
212
213 dev->keycode = map;
214 dev->keycodemax = map_size;
215 dev->getkeycode = sparse_keymap_getkeycode;
216 dev->setkeycode = sparse_keymap_setkeycode;
217
218 return 0;
219}
220EXPORT_SYMBOL(sparse_keymap_setup);
221
222/**
223 * sparse_keymap_report_entry - report event corresponding to given key entry
224 * @dev: Input device for which event should be reported
225 * @ke: key entry describing event
226 * @value: Value that should be reported (ignored by %KE_SW entries)
227 * @autorelease: Signals whether release event should be emitted for %KE_KEY
228 * entries right after reporting press event, ignored by all other
229 * entries
230 *
231 * This function is used to report input event described by given
232 * &struct key_entry.
233 */
234void sparse_keymap_report_entry(struct input_dev *dev, const struct key_entry *ke,
235 unsigned int value, bool autorelease)
236{
237 switch (ke->type) {
238 case KE_KEY:
239 input_event(dev, EV_MSC, MSC_SCAN, ke->code);
240 input_report_key(dev, ke->keycode, value);
241 input_sync(dev);
242 if (value && autorelease) {
243 input_report_key(dev, ke->keycode, 0);
244 input_sync(dev);
245 }
246 break;
247
248 case KE_SW:
249 value = ke->sw.value;
250 fallthrough;
251
252 case KE_VSW:
253 input_report_switch(dev, ke->sw.code, value);
254 input_sync(dev);
255 break;
256 }
257}
258EXPORT_SYMBOL(sparse_keymap_report_entry);
259
260/**
261 * sparse_keymap_report_event - report event corresponding to given scancode
262 * @dev: Input device using sparse keymap
263 * @code: Scan code
264 * @value: Value that should be reported (ignored by %KE_SW entries)
265 * @autorelease: Signals whether release event should be emitted for %KE_KEY
266 * entries right after reporting press event, ignored by all other
267 * entries
268 *
269 * This function is used to perform lookup in an input device using sparse
270 * keymap and report corresponding event. Returns %true if lookup was
271 * successful and %false otherwise.
272 */
273bool sparse_keymap_report_event(struct input_dev *dev, unsigned int code,
274 unsigned int value, bool autorelease)
275{
276 const struct key_entry *ke =
277 sparse_keymap_entry_from_scancode(dev, code);
278 struct key_entry unknown_ke;
279
280 if (ke) {
281 sparse_keymap_report_entry(dev, ke, value, autorelease);
282 return true;
283 }
284
285 /* Report an unknown key event as a debugging aid */
286 unknown_ke.type = KE_KEY;
287 unknown_ke.code = code;
288 unknown_ke.keycode = KEY_UNKNOWN;
289 sparse_keymap_report_entry(dev, &unknown_ke, value, true);
290
291 return false;
292}
293EXPORT_SYMBOL(sparse_keymap_report_event);
294
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/slab.h>
19
20MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
21MODULE_DESCRIPTION("Generic support for sparse keymaps");
22MODULE_LICENSE("GPL v2");
23MODULE_VERSION("0.1");
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 deeds, 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 * Before destroying input device allocated keymap should be freed
167 * with a call to sparse_keymap_free().
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 = kcalloc(map_size, sizeof (struct key_entry), GFP_KERNEL);
183 if (!map)
184 return -ENOMEM;
185
186 memcpy(map, keymap, map_size * sizeof (struct key_entry));
187
188 for (i = 0; i < map_size; i++) {
189 entry = &map[i];
190
191 if (setup) {
192 error = setup(dev, entry);
193 if (error)
194 goto err_out;
195 }
196
197 switch (entry->type) {
198 case KE_KEY:
199 __set_bit(EV_KEY, dev->evbit);
200 __set_bit(entry->keycode, dev->keybit);
201 break;
202
203 case KE_SW:
204 case KE_VSW:
205 __set_bit(EV_SW, dev->evbit);
206 __set_bit(entry->sw.code, dev->swbit);
207 break;
208 }
209 }
210
211 if (test_bit(EV_KEY, dev->evbit)) {
212 __set_bit(KEY_UNKNOWN, dev->keybit);
213 __set_bit(EV_MSC, dev->evbit);
214 __set_bit(MSC_SCAN, dev->mscbit);
215 }
216
217 dev->keycode = map;
218 dev->keycodemax = map_size;
219 dev->getkeycode = sparse_keymap_getkeycode;
220 dev->setkeycode = sparse_keymap_setkeycode;
221
222 return 0;
223
224 err_out:
225 kfree(map);
226 return error;
227}
228EXPORT_SYMBOL(sparse_keymap_setup);
229
230/**
231 * sparse_keymap_free - free memory allocated for sparse keymap
232 * @dev: Input device using sparse keymap
233 *
234 * This function is used to free memory allocated by sparse keymap
235 * in an input device that was set up by sparse_keymap_setup().
236 * NOTE: It is safe to cal this function while input device is
237 * still registered (however the drivers should care not to try to
238 * use freed keymap and thus have to shut off interrups/polling
239 * before freeing the keymap).
240 */
241void sparse_keymap_free(struct input_dev *dev)
242{
243 unsigned long flags;
244
245 /*
246 * Take event lock to prevent racing with input_get_keycode()
247 * and input_set_keycode() if we are called while input device
248 * is still registered.
249 */
250 spin_lock_irqsave(&dev->event_lock, flags);
251
252 kfree(dev->keycode);
253 dev->keycode = NULL;
254 dev->keycodemax = 0;
255
256 spin_unlock_irqrestore(&dev->event_lock, flags);
257}
258EXPORT_SYMBOL(sparse_keymap_free);
259
260/**
261 * sparse_keymap_report_entry - report event corresponding to given key entry
262 * @dev: Input device for which event should be reported
263 * @ke: key entry describing event
264 * @value: Value that should be reported (ignored by %KE_SW entries)
265 * @autorelease: Signals whether release event should be emitted for %KE_KEY
266 * entries right after reporting press event, ignored by all other
267 * entries
268 *
269 * This function is used to report input event described by given
270 * &struct key_entry.
271 */
272void sparse_keymap_report_entry(struct input_dev *dev, const struct key_entry *ke,
273 unsigned int value, bool autorelease)
274{
275 switch (ke->type) {
276 case KE_KEY:
277 input_event(dev, EV_MSC, MSC_SCAN, ke->code);
278 input_report_key(dev, ke->keycode, value);
279 input_sync(dev);
280 if (value && autorelease) {
281 input_report_key(dev, ke->keycode, 0);
282 input_sync(dev);
283 }
284 break;
285
286 case KE_SW:
287 value = ke->sw.value;
288 /* fall through */
289
290 case KE_VSW:
291 input_report_switch(dev, ke->sw.code, value);
292 break;
293 }
294}
295EXPORT_SYMBOL(sparse_keymap_report_entry);
296
297/**
298 * sparse_keymap_report_event - report event corresponding to given scancode
299 * @dev: Input device using sparse keymap
300 * @code: Scan code
301 * @value: Value that should be reported (ignored by %KE_SW entries)
302 * @autorelease: Signals whether release event should be emitted for %KE_KEY
303 * entries right after reporting press event, ignored by all other
304 * entries
305 *
306 * This function is used to perform lookup in an input device using sparse
307 * keymap and report corresponding event. Returns %true if lookup was
308 * successful and %false otherwise.
309 */
310bool sparse_keymap_report_event(struct input_dev *dev, unsigned int code,
311 unsigned int value, bool autorelease)
312{
313 const struct key_entry *ke =
314 sparse_keymap_entry_from_scancode(dev, code);
315 struct key_entry unknown_ke;
316
317 if (ke) {
318 sparse_keymap_report_entry(dev, ke, value, autorelease);
319 return true;
320 }
321
322 /* Report an unknown key event as a debugging aid */
323 unknown_ke.type = KE_KEY;
324 unknown_ke.code = code;
325 unknown_ke.keycode = KEY_UNKNOWN;
326 sparse_keymap_report_entry(dev, &unknown_ke, value, true);
327
328 return false;
329}
330EXPORT_SYMBOL(sparse_keymap_report_event);
331