drivers/input/sparse-keymap.c

   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 MODULE_VERSION("0.1");
  25
  26 static unsigned int sparse_keymap_get_key_index(struct input_dev *dev,
  27                                                 const struct key_entry *k)
  28 {
  29         struct key_entry *key;
  30         unsigned int idx = 0;
  31
  32         for (key = dev->keycode; key->type != KE_END; key++) {
  33                 if (key->type == KE_KEY) {
  34                         if (key == k)
  35                                 break;
  36                         idx++;
  37                 }
  38         }
  39
  40         return idx;
  41 }
  42
  43 static struct key_entry *sparse_keymap_entry_by_index(struct input_dev *dev,
  44                                                       unsigned int index)
  45 {
  46         struct key_entry *key;
  47         unsigned int key_cnt = 0;
  48
  49         for (key = dev->keycode; key->type != KE_END; key++)
  50                 if (key->type == KE_KEY)
  51                         if (key_cnt++ == index)
  52                                 return key;
  53
  54         return NULL;
  55 }
  56
  57 /**
  58  * sparse_keymap_entry_from_scancode - perform sparse keymap lookup
  59  * @dev: Input device using sparse keymap
  60  * @code: Scan code
  61  *
  62  * This function is used to perform &struct key_entry lookup in an
  63  * input device using sparse keymap.
  64  */
  65 struct key_entry *sparse_keymap_entry_from_scancode(struct input_dev *dev,
  66                                                     unsigned int code)
  67 {
  68         struct key_entry *key;
  69
  70         for (key = dev->keycode; key->type != KE_END; key++)
  71                 if (code == key->code)
  72                         return key;
  73
  74         return NULL;
  75 }
  76 EXPORT_SYMBOL(sparse_keymap_entry_from_scancode);
  77
  78 /**
  79  * sparse_keymap_entry_from_keycode - perform sparse keymap lookup
  80  * @dev: Input device using sparse keymap
  81  * @keycode: Key code
  82  *
  83  * This function is used to perform &struct key_entry lookup in an
  84  * input device using sparse keymap.
  85  */
  86 struct key_entry *sparse_keymap_entry_from_keycode(struct input_dev *dev,
  87                                                    unsigned int keycode)
  88 {
  89         struct key_entry *key;
  90
  91         for (key = dev->keycode; key->type != KE_END; key++)
  92                 if (key->type == KE_KEY && keycode == key->keycode)
  93                         return key;
  94
  95         return NULL;
  96 }
  97 EXPORT_SYMBOL(sparse_keymap_entry_from_keycode);
  98
  99 static struct key_entry *sparse_keymap_locate(struct input_dev *dev,
 100                                         const struct input_keymap_entry *ke)
 101 {
 102         struct key_entry *key;
 103         unsigned int scancode;
 104
 105         if (ke->flags & INPUT_KEYMAP_BY_INDEX)
 106                 key = sparse_keymap_entry_by_index(dev, ke->index);
 107         else if (input_scancode_to_scalar(ke, &scancode) == 0)
 108                 key = sparse_keymap_entry_from_scancode(dev, scancode);
 109         else
 110                 key = NULL;
 111
 112         return key;
 113 }
 114
 115 static int sparse_keymap_getkeycode(struct input_dev *dev,
 116                                     struct input_keymap_entry *ke)
 117 {
 118         const struct key_entry *key;
 119
 120         if (dev->keycode) {
 121                 key = sparse_keymap_locate(dev, ke);
 122                 if (key && key->type == KE_KEY) {
 123                         ke->keycode = key->keycode;
 124                         if (!(ke->flags & INPUT_KEYMAP_BY_INDEX))
 125                                 ke->index =
 126                                         sparse_keymap_get_key_index(dev, key);
 127                         ke->len = sizeof(key->code);
 128                         memcpy(ke->scancode, &key->code, sizeof(key->code));
 129                         return 0;
 130                 }
 131         }
 132
 133         return -EINVAL;
 134 }
 135
 136 static int sparse_keymap_setkeycode(struct input_dev *dev,
 137                                     const struct input_keymap_entry *ke,
 138                                     unsigned int *old_keycode)
 139 {
 140         struct key_entry *key;
 141
 142         if (dev->keycode) {
 143                 key = sparse_keymap_locate(dev, ke);
 144                 if (key && key->type == KE_KEY) {
 145                         *old_keycode = key->keycode;
 146                         key->keycode = ke->keycode;
 147                         set_bit(ke->keycode, dev->keybit);
 148                         if (!sparse_keymap_entry_from_keycode(dev, *old_keycode))
 149                                 clear_bit(*old_keycode, dev->keybit);
 150                         return 0;
 151                 }
 152         }
 153
 154         return -EINVAL;
 155 }
 156
 157 /**
 158  * sparse_keymap_setup - set up sparse keymap for an input device
 159  * @dev: Input device
 160  * @keymap: Keymap in form of array of &key_entry structures ending
 161  *      with %KE_END type entry
 162  * @setup: Function that can be used to adjust keymap entries
 163  *      depending on device's needs, may be %NULL
 164  *
 165  * The function calculates size and allocates copy of the original
 166  * keymap after which sets up input device event bits appropriately.
 167  * The allocated copy of the keymap is automatically freed when it
 168  * is no longer needed.
 169  */
 170 int sparse_keymap_setup(struct input_dev *dev,
 171                         const struct key_entry *keymap,
 172                         int (*setup)(struct input_dev *, struct key_entry *))
 173 {
 174         size_t map_size = 1; /* to account for the last KE_END entry */
 175         const struct key_entry *e;
 176         struct key_entry *map, *entry;
 177         int i;
 178         int error;
 179
 180         for (e = keymap; e->type != KE_END; e++)
 181                 map_size++;
 182
 183         map = devm_kmemdup(&dev->dev, keymap, map_size * sizeof(*map),
 184                            GFP_KERNEL);
 185         if (!map)
 186                 return -ENOMEM;
 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                                 return error;
 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 EXPORT_SYMBOL(sparse_keymap_setup);
 225
 226 /**
 227  * sparse_keymap_report_entry - report event corresponding to given key entry
 228  * @dev: Input device for which event should be reported
 229  * @ke: key entry describing event
 230  * @value: Value that should be reported (ignored by %KE_SW entries)
 231  * @autorelease: Signals whether release event should be emitted for %KE_KEY
 232  *      entries right after reporting press event, ignored by all other
 233  *      entries
 234  *
 235  * This function is used to report input event described by given
 236  * &struct key_entry.
 237  */
 238 void sparse_keymap_report_entry(struct input_dev *dev, const struct key_entry *ke,
 239                                 unsigned int value, bool autorelease)
 240 {
 241         switch (ke->type) {
 242         case KE_KEY:
 243                 input_event(dev, EV_MSC, MSC_SCAN, ke->code);
 244                 input_report_key(dev, ke->keycode, value);
 245                 input_sync(dev);
 246                 if (value && autorelease) {
 247                         input_report_key(dev, ke->keycode, 0);
 248                         input_sync(dev);
 249                 }
 250                 break;
 251
 252         case KE_SW:
 253                 value = ke->sw.value;
 254                 /* fall through */
 255
 256         case KE_VSW:
 257                 input_report_switch(dev, ke->sw.code, value);
 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