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/slab.h>
  19
  20 MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
  21 MODULE_DESCRIPTION("Generic support for sparse keymaps");
  22 MODULE_LICENSE("GPL v2");
  23 MODULE_VERSION("0.1");
  24
  25 /**
  26  * sparse_keymap_entry_from_scancode - perform sparse keymap lookup
  27  * @dev: Input device using sparse keymap
  28  * @code: Scan code
  29  *
  30  * This function is used to perform &struct key_entry lookup in an
  31  * input device using sparse keymap.
  32  */
  33 struct key_entry *sparse_keymap_entry_from_scancode(struct input_dev *dev,
  34                                                     unsigned int code)
  35 {
  36         struct key_entry *key;
  37
  38         for (key = dev->keycode; key->type != KE_END; key++)
  39                 if (code == key->code)
  40                         return key;
  41
  42         return NULL;
  43 }
  44 EXPORT_SYMBOL(sparse_keymap_entry_from_scancode);
  45
  46 /**
  47  * sparse_keymap_entry_from_keycode - perform sparse keymap lookup
  48  * @dev: Input device using sparse keymap
  49  * @keycode: Key code
  50  *
  51  * This function is used to perform &struct key_entry lookup in an
  52  * input device using sparse keymap.
  53  */
  54 struct key_entry *sparse_keymap_entry_from_keycode(struct input_dev *dev,
  55                                                    unsigned int keycode)
  56 {
  57         struct key_entry *key;
  58
  59         for (key = dev->keycode; key->type != KE_END; key++)
  60                 if (key->type == KE_KEY && keycode == key->keycode)
  61                         return key;
  62
  63         return NULL;
  64 }
  65 EXPORT_SYMBOL(sparse_keymap_entry_from_keycode);
  66
  67 static int sparse_keymap_getkeycode(struct input_dev *dev,
  68                                     unsigned int scancode,
  69                                     unsigned int *keycode)
  70 {
  71         const struct key_entry *key =
  72                         sparse_keymap_entry_from_scancode(dev, scancode);
  73
  74         if (key && key->type == KE_KEY) {
  75                 *keycode = key->keycode;
  76                 return 0;
  77         }
  78
  79         return -EINVAL;
  80 }
  81
  82 static int sparse_keymap_setkeycode(struct input_dev *dev,
  83                                     unsigned int scancode,
  84                                     unsigned int keycode)
  85 {
  86         struct key_entry *key;
  87         int old_keycode;
  88
  89         if (keycode < 0 || keycode > KEY_MAX)
  90                 return -EINVAL;
  91
  92         key = sparse_keymap_entry_from_scancode(dev, scancode);
  93         if (key && key->type == KE_KEY) {
  94                 old_keycode = key->keycode;
  95                 key->keycode = keycode;
  96                 set_bit(keycode, dev->keybit);
  97                 if (!sparse_keymap_entry_from_keycode(dev, old_keycode))
  98                         clear_bit(old_keycode, dev->keybit);
  99                 return 0;
 100         }
 101
 102         return -EINVAL;
 103 }
 104
 105 /**
 106  * sparse_keymap_setup - set up sparse keymap for an input device
 107  * @dev: Input device
 108  * @keymap: Keymap in form of array of &key_entry structures ending
 109  *      with %KE_END type entry
 110  * @setup: Function that can be used to adjust keymap entries
 111  *      depending on device's deeds, may be %NULL
 112  *
 113  * The function calculates size and allocates copy of the original
 114  * keymap after which sets up input device event bits appropriately.
 115  * Before destroying input device allocated keymap should be freed
 116  * with a call to sparse_keymap_free().
 117  */
 118 int sparse_keymap_setup(struct input_dev *dev,
 119                         const struct key_entry *keymap,
 120                         int (*setup)(struct input_dev *, struct key_entry *))
 121 {
 122         size_t map_size = 1; /* to account for the last KE_END entry */
 123         const struct key_entry *e;
 124         struct key_entry *map, *entry;
 125         int i;
 126         int error;
 127
 128         for (e = keymap; e->type != KE_END; e++)
 129                 map_size++;
 130
 131         map = kcalloc(map_size, sizeof (struct key_entry), GFP_KERNEL);
 132         if (!map)
 133                 return -ENOMEM;
 134
 135         memcpy(map, keymap, map_size * sizeof (struct key_entry));
 136
 137         for (i = 0; i < map_size; i++) {
 138                 entry = &map[i];
 139
 140                 if (setup) {
 141                         error = setup(dev, entry);
 142                         if (error)
 143                                 goto err_out;
 144                 }
 145
 146                 switch (entry->type) {
 147                 case KE_KEY:
 148                         __set_bit(EV_KEY, dev->evbit);
 149                         __set_bit(entry->keycode, dev->keybit);
 150                         break;
 151
 152                 case KE_SW:
 153                         __set_bit(EV_SW, dev->evbit);
 154                         __set_bit(entry->sw.code, dev->swbit);
 155                         break;
 156                 }
 157         }
 158
 159         dev->keycode = map;
 160         dev->keycodemax = map_size;
 161         dev->getkeycode = sparse_keymap_getkeycode;
 162         dev->setkeycode = sparse_keymap_setkeycode;
 163
 164         return 0;
 165
 166  err_out:
 167         kfree(keymap);
 168         return error;
 169
 170 }
 171 EXPORT_SYMBOL(sparse_keymap_setup);
 172
 173 /**
 174  * sparse_keymap_free - free memory allocated for sparse keymap
 175  * @dev: Input device using sparse keymap
 176  *
 177  * This function is used to free memory allocated by sparse keymap
 178  * in an input device that was set up by sparse_keymap_setup().
 179  */
 180 void sparse_keymap_free(struct input_dev *dev)
 181 {
 182         kfree(dev->keycode);
 183         dev->keycode = NULL;
 184         dev->keycodemax = 0;
 185         dev->getkeycode = NULL;
 186         dev->setkeycode = NULL;
 187 }
 188 EXPORT_SYMBOL(sparse_keymap_free);
 189
 190 /**
 191  * sparse_keymap_report_entry - report event corresponding to given key entry
 192  * @dev: Input device for which event should be reported
 193  * @ke: key entry describing event
 194  * @value: Value that should be reported (ignored by %KE_SW entries)
 195  * @autorelease: Signals whether release event should be emitted for %KE_KEY
 196  *      entries right after reporting press event, ignored by all other
 197  *      entries
 198  *
 199  * This function is used to report input event described by given
 200  * &struct key_entry.
 201  */
 202 void sparse_keymap_report_entry(struct input_dev *dev, const struct key_entry *ke,
 203                                 unsigned int value, bool autorelease)
 204 {
 205         switch (ke->type) {
 206         case KE_KEY:
 207                 input_report_key(dev, ke->keycode, value);
 208                 input_sync(dev);
 209                 if (value && autorelease) {
 210                         input_report_key(dev, ke->keycode, 0);
 211                         input_sync(dev);
 212                 }
 213                 break;
 214
 215         case KE_SW:
 216                 value = ke->sw.value;
 217                 /* fall through */
 218
 219         case KE_VSW:
 220                 input_report_switch(dev, ke->sw.code, value);
 221                 break;
 222         }
 223 }
 224 EXPORT_SYMBOL(sparse_keymap_report_entry);
 225
 226 /**
 227  * sparse_keymap_report_event - report event corresponding to given scancode
 228  * @dev: Input device using sparse keymap
 229  * @code: Scan code
 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 perform lookup in an input device using sparse
 236  * keymap and report corresponding event. Returns %true if lookup was
 237  * successful and %false otherwise.
 238  */
 239 bool sparse_keymap_report_event(struct input_dev *dev, unsigned int code,
 240                                 unsigned int value, bool autorelease)
 241 {
 242         const struct key_entry *ke =
 243                 sparse_keymap_entry_from_scancode(dev, code);
 244
 245         if (ke) {
 246                 sparse_keymap_report_entry(dev, ke, value, autorelease);
 247                 return true;
 248         }
 249
 250         return false;
 251 }
 252 EXPORT_SYMBOL(sparse_keymap_report_event);
 253