drivers/input/input.c

   1 /*
   2  * Translate key codes into ASCII
   3  *
   4  * Copyright (c) 2011 The Chromium OS Authors.
   5  * (C) Copyright 2004 DENX Software Engineering, Wolfgang Denk, wd@denx.de
   6  *
   7  * See file CREDITS for list of people who contributed to this
   8  * project.
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License as
  12  * published by the Free Software Foundation; either version 2 of
  13  * the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  23  * MA 02111-1307 USA
  24  */
  25
  26 #include <common.h>
  27 #include <stdio_dev.h>
  28 #include <input.h>
  29 #include <linux/input.h>
  30
  31 enum {
  32         /* These correspond to the lights on the keyboard */
  33         FLAG_NUM_LOCK           = 1 << 0,
  34         FLAG_CAPS_LOCK          = 1 << 1,
  35         FLAG_SCROLL_LOCK        = 1 << 2,
  36
  37         /* Special flag ORed with key code to indicate release */
  38         KEY_RELEASE             = 1 << 15,
  39         KEY_MASK                = 0xfff,
  40 };
  41
  42 /*
  43  * These takes map key codes to ASCII. 0xff means no key, or special key.
  44  * Three tables are provided - one for plain keys, one for when the shift
  45  * 'modifier' key is pressed and one for when the ctrl modifier key is
  46  * pressed.
  47  */
  48 static const uchar kbd_plain_xlate[] = {
  49         0xff, 0x1b, '1',  '2',  '3',  '4',  '5',  '6',
  50         '7',  '8',  '9',  '0',  '-',  '=', '\b', '\t',  /* 0x00 - 0x0f */
  51         'q',  'w',  'e',  'r',  't',  'y',  'u',  'i',
  52         'o',  'p',  '[',  ']', '\r', 0xff,  'a',  's',  /* 0x10 - 0x1f */
  53         'd',  'f',  'g',  'h',  'j',  'k',  'l',  ';',
  54         '\'',  '`', 0xff, '\\', 'z',  'x',  'c',  'v',  /* 0x20 - 0x2f */
  55         'b',  'n',  'm',  ',' ,  '.', '/', 0xff, 0xff, 0xff,
  56         ' ', 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,        /* 0x30 - 0x3f */
  57         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,  '7',
  58         '8',  '9',  '-',  '4',  '5',  '6',  '+',  '1',  /* 0x40 - 0x4f */
  59         '2',  '3',  '0',  '.', 0xff, 0xff, 0xff, 0xff,
  60         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x50 - 0x5F */
  61         '\r', 0xff, 0xff
  62 };
  63
  64 static unsigned char kbd_shift_xlate[] = {
  65         0xff, 0x1b, '!', '@', '#', '$', '%', '^',
  66         '&', '*', '(', ')', '_', '+', '\b', '\t',       /* 0x00 - 0x0f */
  67         'Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I',
  68         'O', 'P', '{', '}', '\r', 0xff, 'A', 'S',       /* 0x10 - 0x1f */
  69         'D', 'F', 'G', 'H', 'J', 'K', 'L', ':',
  70         '"', '~', 0xff, '|', 'Z', 'X', 'C', 'V',        /* 0x20 - 0x2f */
  71         'B', 'N', 'M', '<', '>', '?', 0xff, 0xff, 0xff,
  72         ' ', 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,        /* 0x30 - 0x3f */
  73         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, '7',
  74         '8', '9', '-', '4', '5', '6', '+', '1', /* 0x40 - 0x4f */
  75         '2', '3', '0', '.', 0xff, 0xff, 0xff, 0xff, 0xff,
  76         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,       /* 0x50 - 0x5F */
  77         '\r', 0xff, 0xff
  78 };
  79
  80 static unsigned char kbd_ctrl_xlate[] = {
  81         0xff, 0x1b, '1', 0x00, '3', '4', '5', 0x1E,
  82         '7', '8', '9', '0', 0x1F, '=', '\b', '\t',      /* 0x00 - 0x0f */
  83         0x11, 0x17, 0x05, 0x12, 0x14, 0x18, 0x15, 0x09,
  84         0x0f, 0x10, 0x1b, 0x1d, '\n', 0xff, 0x01, 0x13, /* 0x10 - 0x1f */
  85         0x04, 0x06, 0x08, 0x09, 0x0a, 0x0b, 0x0c, ';',
  86         '\'', '~', 0x00, 0x1c, 0x1a, 0x18, 0x03, 0x16,  /* 0x20 - 0x2f */
  87         0x02, 0x0e, 0x0d, '<', '>', '?', 0xff, 0xff,
  88         0xff, 0x00, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x30 - 0x3f */
  89         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, '7',
  90         '8', '9', '-', '4', '5', '6', '+', '1',         /* 0x40 - 0x4f */
  91         '2', '3', '0', '.', 0xff, 0xff, 0xff, 0xff,
  92         0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0x50 - 0x5F */
  93         '\r', 0xff, 0xff
  94 };
  95
  96 /*
  97  * Scan key code to ANSI 3.64 escape sequence table.  This table is
  98  * incomplete in that it does not include all possible extra keys.
  99  */
 100 static struct {
 101         int kbd_scan_code;
 102         char *escape;
 103 } kbd_to_ansi364[] = {
 104         { KEY_UP, "\033[A"},
 105         { KEY_DOWN, "\033[B"},
 106         { KEY_RIGHT, "\033[C"},
 107         { KEY_LEFT, "\033[D"},
 108 };
 109
 110 /* Maximum number of output characters that an ANSI sequence expands to */
 111 #define ANSI_CHAR_MAX   3
 112
 113 int input_queue_ascii(struct input_config *config, int ch)
 114 {
 115         if (config->fifo_in + 1 == INPUT_BUFFER_LEN) {
 116                 if (!config->fifo_out)
 117                         return -1; /* buffer full */
 118                 else
 119                         config->fifo_in = 0;
 120         } else {
 121                 if (config->fifo_in + 1 == config->fifo_out)
 122                         return -1; /* buffer full */
 123                 config->fifo_in++;
 124         }
 125         config->fifo[config->fifo_in] = (uchar)ch;
 126
 127         return 0;
 128 }
 129
 130 int input_tstc(struct input_config *config)
 131 {
 132         if (config->fifo_in == config->fifo_out && config->read_keys) {
 133                 if (!(*config->read_keys)(config))
 134                         return 0;
 135         }
 136         return config->fifo_in != config->fifo_out;
 137 }
 138
 139 int input_getc(struct input_config *config)
 140 {
 141         int err = 0;
 142
 143         while (config->fifo_in == config->fifo_out) {
 144                 if (config->read_keys)
 145                         err = (*config->read_keys)(config);
 146                 if (err)
 147                         return -1;
 148         }
 149
 150         if (++config->fifo_out == INPUT_BUFFER_LEN)
 151                 config->fifo_out = 0;
 152
 153         return config->fifo[config->fifo_out];
 154 }
 155
 156 /**
 157  * Process a modifier/special key press or release and decide which key
 158  * translation array should be used as a result.
 159  *
 160  * TODO: Should keep track of modifier press/release
 161  *
 162  * @param config        Input state
 163  * @param key           Key code to process
 164  * @param release       0 if a press, 1 if a release
 165  * @return pointer to keycode->ascii translation table that should be used
 166  */
 167 static struct input_key_xlate *process_modifier(struct input_config *config,
 168                                                 int key, int release)
 169 {
 170         struct input_key_xlate *table;
 171         int flip = -1;
 172         int i;
 173
 174         /* Start with the main table, and see what modifiers change it */
 175         assert(config->num_tables > 0);
 176         table = &config->table[0];
 177         for (i = 1; i < config->num_tables; i++) {
 178                 struct input_key_xlate *tab = &config->table[i];
 179
 180                 if (key == tab->left_keycode || key == tab->right_keycode)
 181                         table = tab;
 182         }
 183
 184         /* Handle the lighted keys */
 185         if (!release) {
 186                 switch (key) {
 187                 case KEY_SCROLLLOCK:
 188                         flip = FLAG_SCROLL_LOCK;
 189                         break;
 190                 case KEY_NUMLOCK:
 191                         flip = FLAG_NUM_LOCK;
 192                         break;
 193                 case KEY_CAPSLOCK:
 194                         flip = FLAG_CAPS_LOCK;
 195                         break;
 196                 }
 197         }
 198
 199         if (flip != -1) {
 200                 int leds = 0;
 201
 202                 config->leds ^= flip;
 203                 if (config->flags & FLAG_NUM_LOCK)
 204                         leds |= INPUT_LED_NUM;
 205                 if (config->flags & FLAG_CAPS_LOCK)
 206                         leds |= INPUT_LED_CAPS;
 207                 if (config->flags & FLAG_SCROLL_LOCK)
 208                         leds |= INPUT_LED_SCROLL;
 209                 config->leds = leds;
 210         }
 211
 212         return table;
 213 }
 214
 215 /**
 216  * Search an int array for a key value
 217  *
 218  * @param array Array to search
 219  * @param count Number of elements in array
 220  * @param key   Key value to find
 221  * @return element where value was first found, -1 if none
 222  */
 223 static int array_search(int *array, int count, int key)
 224 {
 225         int i;
 226
 227         for (i = 0; i < count; i++) {
 228                 if (array[i] == key)
 229                         return i;
 230         }
 231
 232         return -1;
 233 }
 234
 235 /**
 236  * Sort an array so that those elements that exist in the ordering are
 237  * first in the array, and in the same order as the ordering. The algorithm
 238  * is O(count * ocount) and designed for small arrays.
 239  *
 240  * TODO: Move this to common / lib?
 241  *
 242  * @param dest          Array with elements to sort, also destination array
 243  * @param count         Number of elements to sort
 244  * @param order         Array containing ordering elements
 245  * @param ocount        Number of ordering elements
 246  * @return number of elements in dest that are in order (these will be at the
 247  *      start of dest).
 248  */
 249 static int sort_array_by_ordering(int *dest, int count, int *order,
 250                                    int ocount)
 251 {
 252         int temp[count];
 253         int dest_count;
 254         int same;       /* number of elements which are the same */
 255         int i;
 256
 257         /* setup output items, copy items to be sorted into our temp area */
 258         memcpy(temp, dest, count * sizeof(*dest));
 259         dest_count = 0;
 260
 261         /* work through the ordering, move over the elements we agree on */
 262         for (i = 0; i < ocount; i++) {
 263                 if (array_search(temp, count, order[i]) != -1)
 264                         dest[dest_count++] = order[i];
 265         }
 266         same = dest_count;
 267
 268         /* now move over the elements that are not in the ordering */
 269         for (i = 0; i < count; i++) {
 270                 if (array_search(order, ocount, temp[i]) == -1)
 271                         dest[dest_count++] = temp[i];
 272         }
 273         assert(dest_count == count);
 274         return same;
 275 }
 276
 277 /**
 278  * Check a list of key codes against the previous key scan
 279  *
 280  * Given a list of new key codes, we check how many of these are the same
 281  * as last time.
 282  *
 283  * @param config        Input state
 284  * @param keycode       List of key codes to examine
 285  * @param num_keycodes  Number of key codes
 286  * @param same          Returns number of key codes which are the same
 287  */
 288 static int input_check_keycodes(struct input_config *config,
 289                            int keycode[], int num_keycodes, int *same)
 290 {
 291         /* Select the 'plain' xlate table to start with */
 292         if (!config->num_tables) {
 293                 debug("%s: No xlate tables: cannot decode keys\n", __func__);
 294                 return -1;
 295         }
 296
 297         /* sort the keycodes into the same order as the previous ones */
 298         *same = sort_array_by_ordering(keycode, num_keycodes,
 299                         config->prev_keycodes, config->num_prev_keycodes);
 300
 301         memcpy(config->prev_keycodes, keycode, num_keycodes * sizeof(int));
 302         config->num_prev_keycodes = num_keycodes;
 303
 304         return *same != num_keycodes;
 305 }
 306
 307 /**
 308  * Checks and converts a special key code into ANSI 3.64 escape sequence.
 309  *
 310  * @param config        Input state
 311  * @param keycode       Key code to examine
 312  * @param output_ch     Buffer to place output characters into. It should
 313  *                      be at least ANSI_CHAR_MAX bytes long, to allow for
 314  *                      an ANSI sequence.
 315  * @param max_chars     Maximum number of characters to add to output_ch
 316  * @return number of characters output, if the key was converted, otherwise 0.
 317  *      This may be larger than max_chars, in which case the overflow
 318  *      characters are not output.
 319  */
 320 static int input_keycode_to_ansi364(struct input_config *config,
 321                 int keycode, char output_ch[], int max_chars)
 322 {
 323         const char *escape;
 324         int ch_count;
 325         int i;
 326
 327         for (i = ch_count = 0; i < ARRAY_SIZE(kbd_to_ansi364); i++) {
 328                 if (keycode != kbd_to_ansi364[i].kbd_scan_code)
 329                         continue;
 330                 for (escape = kbd_to_ansi364[i].escape; *escape; escape++) {
 331                         if (ch_count < max_chars)
 332                                 output_ch[ch_count] = *escape;
 333                         ch_count++;
 334                 }
 335                 return ch_count;
 336         }
 337
 338         return 0;
 339 }
 340
 341 /**
 342  * Converts and queues a list of key codes in escaped ASCII string form
 343  * Convert a list of key codes into ASCII
 344  *
 345  * You must call input_check_keycodes() before this. It turns the keycode
 346  * list into a list of ASCII characters and sends them to the input layer.
 347  *
 348  * Characters which were seen last time do not generate fresh ASCII output.
 349  * The output (calls to queue_ascii) may be longer than num_keycodes, if the
 350  * keycode contains special keys that was encoded to longer escaped sequence.
 351  *
 352  * @param config        Input state
 353  * @param keycode       List of key codes to examine
 354  * @param num_keycodes  Number of key codes
 355  * @param output_ch     Buffer to place output characters into. It should
 356  *                      be at last ANSI_CHAR_MAX * num_keycodes, to allow for
 357  *                      ANSI sequences.
 358  * @param max_chars     Maximum number of characters to add to output_ch
 359  * @param same          Number of key codes which are the same
 360  * @return number of characters written into output_ch, or -1 if we would
 361  *      exceed max_chars chars.
 362  */
 363 static int input_keycodes_to_ascii(struct input_config *config,
 364                 int keycode[], int num_keycodes, char output_ch[],
 365                 int max_chars, int same)
 366 {
 367         struct input_key_xlate *table;
 368         int ch_count = 0;
 369         int i;
 370
 371         table = &config->table[0];
 372
 373         /* deal with modifiers first */
 374         for (i = 0; i < num_keycodes; i++) {
 375                 int key = keycode[i] & KEY_MASK;
 376
 377                 if (key >= table->num_entries || table->xlate[key] == 0xff) {
 378                         table = process_modifier(config, key,
 379                                         keycode[i] & KEY_RELEASE);
 380                 }
 381         }
 382
 383         /* Start conversion by looking for the first new keycode (by same). */
 384         for (i = same; i < num_keycodes; i++) {
 385                 int key = keycode[i];
 386                 int ch = (key < table->num_entries) ? table->xlate[key] : 0xff;
 387
 388                 /*
 389                  * For a normal key (with an ASCII value), add it; otherwise
 390                  * translate special key to escape sequence if possible.
 391                  */
 392                 if (ch != 0xff) {
 393                         if (ch_count < max_chars)
 394                                 output_ch[ch_count] = (uchar)ch;
 395                         ch_count++;
 396                 } else {
 397                         ch_count += input_keycode_to_ansi364(config, key,
 398                                                 output_ch, max_chars);
 399                 }
 400         }
 401
 402         if (ch_count > max_chars) {
 403                 debug("%s: Output char buffer overflow size=%d, need=%d\n",
 404                       __func__, max_chars, ch_count);
 405                 return -1;
 406         }
 407
 408         /* ok, so return keys */
 409         return ch_count;
 410 }
 411
 412 int input_send_keycodes(struct input_config *config,
 413                         int keycode[], int num_keycodes)
 414 {
 415         char ch[num_keycodes * ANSI_CHAR_MAX];
 416         int count, i, same = 0;
 417         int is_repeat = 0;
 418         unsigned delay_ms;
 419
 420         config->modifiers = 0;
 421         if (!input_check_keycodes(config, keycode, num_keycodes, &same)) {
 422                 /*
 423                  * Same as last time - is it time for another repeat?
 424                  * TODO(sjg@chromium.org) We drop repeats here and since
 425                  * the caller may not call in again for a while, our
 426                  * auto-repeat speed is not quite correct. We should
 427                  * insert another character if we later realise that we
 428                  * have missed a repeat slot.
 429                  */
 430                 is_repeat = config->repeat_rate_ms &&
 431                         (int)get_timer(config->next_repeat_ms) >= 0;
 432                 if (!is_repeat)
 433                         return 0;
 434         }
 435
 436         count = input_keycodes_to_ascii(config, keycode, num_keycodes,
 437                                         ch, sizeof(ch), is_repeat ? 0 : same);
 438         for (i = 0; i < count; i++)
 439                 input_queue_ascii(config, ch[i]);
 440         delay_ms = is_repeat ?
 441                         config->repeat_rate_ms :
 442                         config->repeat_delay_ms;
 443
 444         config->next_repeat_ms = get_timer(0) + delay_ms;
 445
 446         return count;
 447 }
 448
 449 int input_add_table(struct input_config *config, int left_keycode,
 450                     int right_keycode, const uchar *xlate, int num_entries)
 451 {
 452         struct input_key_xlate *table;
 453
 454         if (config->num_tables == INPUT_MAX_MODIFIERS) {
 455                 debug("%s: Too many modifier tables\n", __func__);
 456                 return -1;
 457         }
 458
 459         table = &config->table[config->num_tables++];
 460         table->left_keycode = left_keycode;
 461         table->right_keycode = right_keycode;
 462         table->xlate = xlate;
 463         table->num_entries = num_entries;
 464
 465         return 0;
 466 }
 467
 468 void input_set_delays(struct input_config *config, int repeat_delay_ms,
 469                int repeat_rate_ms)
 470 {
 471         config->repeat_delay_ms = repeat_delay_ms;
 472         config->repeat_rate_ms = repeat_rate_ms;
 473 }
 474
 475 int input_init(struct input_config *config, int leds)
 476 {
 477         memset(config, '\0', sizeof(*config));
 478         config->leds = leds;
 479         if (input_add_table(config, -1, -1,
 480                         kbd_plain_xlate, ARRAY_SIZE(kbd_plain_xlate)) ||
 481                 input_add_table(config, KEY_LEFTSHIFT, KEY_RIGHTSHIFT,
 482                         kbd_shift_xlate, ARRAY_SIZE(kbd_shift_xlate)) ||
 483                 input_add_table(config, KEY_LEFTCTRL, KEY_RIGHTCTRL,
 484                         kbd_ctrl_xlate, ARRAY_SIZE(kbd_ctrl_xlate))) {
 485                 debug("%s: Could not add modifier tables\n", __func__);
 486                 return -1;
 487         }
 488
 489         return 0;
 490 }
 491
 492 int input_stdio_register(struct stdio_dev *dev)
 493 {
 494         int error;
 495
 496         error = stdio_register(dev);
 497
 498         /* check if this is the standard input device */
 499         if (!error && strcmp(getenv("stdin"), dev->name) == 0) {
 500                 /* reassign the console */
 501                 if (OVERWRITE_CONSOLE ||
 502                                 console_assign(stdin, dev->name))
 503                         return -1;
 504         }
 505
 506         return 0;
 507 }