drivers/media/common/ir-functions.c

   1 /*
   2  *
   3  * some common structs and functions to handle infrared remotes via
   4  * input layer ...
   5  *
   6  * (c) 2003 Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]
   7  *
   8  *  This program is free software; you can redistribute it and/or modify
   9  *  it under the terms of the GNU General Public License as published by
  10  *  the Free Software Foundation; either version 2 of the License, or
  11  *  (at your option) any later version.
  12  *
  13  *  This program is distributed in the hope that it will be useful,
  14  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  *  GNU General Public License for more details.
  17  *
  18  *  You should have received a copy of the GNU General Public License
  19  *  along with this program; if not, write to the Free Software
  20  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #include <linux/module.h>
  24 #include <linux/string.h>
  25 #include <linux/jiffies.h>
  26 #include <media/ir-common.h>
  27
  28 /* -------------------------------------------------------------------------- */
  29
  30 MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]");
  31 MODULE_LICENSE("GPL");
  32
  33 static int repeat = 1;
  34 module_param(repeat, int, 0444);
  35 MODULE_PARM_DESC(repeat,"auto-repeat for IR keys (default: on)");
  36
  37 static int debug;    /* debug level (0,1,2) */
  38 module_param(debug, int, 0644);
  39
  40 #define dprintk(level, fmt, arg...)     if (debug >= level) \
  41         printk(KERN_DEBUG fmt , ## arg)
  42
  43 /* -------------------------------------------------------------------------- */
  44
  45 static void ir_input_key_event(struct input_dev *dev, struct ir_input_state *ir)
  46 {
  47         if (KEY_RESERVED == ir->keycode) {
  48                 printk(KERN_INFO "%s: unknown key: key=0x%02x raw=0x%02x down=%d\n",
  49                        dev->name,ir->ir_key,ir->ir_raw,ir->keypressed);
  50                 return;
  51         }
  52         dprintk(1,"%s: key event code=%d down=%d\n",
  53                 dev->name,ir->keycode,ir->keypressed);
  54         input_report_key(dev,ir->keycode,ir->keypressed);
  55         input_sync(dev);
  56 }
  57
  58 /* -------------------------------------------------------------------------- */
  59
  60 void ir_input_init(struct input_dev *dev, struct ir_input_state *ir,
  61                    int ir_type, struct ir_scancode_table *ir_codes)
  62 {
  63         int i;
  64
  65         ir->ir_type = ir_type;
  66
  67         memset(ir->ir_codes, sizeof(ir->ir_codes), 0);
  68
  69         /*
  70          * FIXME: This is a temporary workaround to use the new IR tables
  71          * with the old approach. Later patches will replace this to a
  72          * proper method
  73          */
  74
  75         if (ir_codes)
  76                 for (i = 0; i < ir_codes->size; i++)
  77                         if (ir_codes->scan[i].scancode < IR_KEYTAB_SIZE)
  78                                 ir->ir_codes[ir_codes->scan[i].scancode] = ir_codes->scan[i].keycode;
  79
  80         dev->keycode     = ir->ir_codes;
  81         dev->keycodesize = sizeof(IR_KEYTAB_TYPE);
  82         dev->keycodemax  = IR_KEYTAB_SIZE;
  83         for (i = 0; i < IR_KEYTAB_SIZE; i++)
  84                 set_bit(ir->ir_codes[i], dev->keybit);
  85         clear_bit(0, dev->keybit);
  86
  87         set_bit(EV_KEY, dev->evbit);
  88         if (repeat)
  89                 set_bit(EV_REP, dev->evbit);
  90 }
  91 EXPORT_SYMBOL_GPL(ir_input_init);
  92
  93 void ir_input_nokey(struct input_dev *dev, struct ir_input_state *ir)
  94 {
  95         if (ir->keypressed) {
  96                 ir->keypressed = 0;
  97                 ir_input_key_event(dev,ir);
  98         }
  99 }
 100 EXPORT_SYMBOL_GPL(ir_input_nokey);
 101
 102 void ir_input_keydown(struct input_dev *dev, struct ir_input_state *ir,
 103                       u32 ir_key, u32 ir_raw)
 104 {
 105         u32 keycode = IR_KEYCODE(ir->ir_codes, ir_key);
 106
 107         if (ir->keypressed && ir->keycode != keycode) {
 108                 ir->keypressed = 0;
 109                 ir_input_key_event(dev,ir);
 110         }
 111         if (!ir->keypressed) {
 112                 ir->ir_key  = ir_key;
 113                 ir->ir_raw  = ir_raw;
 114                 ir->keycode = keycode;
 115                 ir->keypressed = 1;
 116                 ir_input_key_event(dev,ir);
 117         }
 118 }
 119 EXPORT_SYMBOL_GPL(ir_input_keydown);
 120
 121 /* -------------------------------------------------------------------------- */
 122 /* extract mask bits out of data and pack them into the result */
 123 u32 ir_extract_bits(u32 data, u32 mask)
 124 {
 125         u32 vbit = 1, value = 0;
 126
 127         do {
 128             if (mask&1) {
 129                 if (data&1)
 130                         value |= vbit;
 131                 vbit<<=1;
 132             }
 133             data>>=1;
 134         } while (mask>>=1);
 135
 136         return value;
 137 }
 138 EXPORT_SYMBOL_GPL(ir_extract_bits);
 139
 140 static int inline getbit(u32 *samples, int bit)
 141 {
 142         return (samples[bit/32] & (1 << (31-(bit%32)))) ? 1 : 0;
 143 }
 144
 145 /* sump raw samples for visual debugging ;) */
 146 int ir_dump_samples(u32 *samples, int count)
 147 {
 148         int i, bit, start;
 149
 150         printk(KERN_DEBUG "ir samples: ");
 151         start = 0;
 152         for (i = 0; i < count * 32; i++) {
 153                 bit = getbit(samples,i);
 154                 if (bit)
 155                         start = 1;
 156                 if (0 == start)
 157                         continue;
 158                 printk("%s", bit ? "#" : "_");
 159         }
 160         printk("\n");
 161         return 0;
 162 }
 163 EXPORT_SYMBOL_GPL(ir_dump_samples);
 164
 165 /* decode raw samples, pulse distance coding used by NEC remotes */
 166 int ir_decode_pulsedistance(u32 *samples, int count, int low, int high)
 167 {
 168         int i,last,bit,len;
 169         u32 curBit;
 170         u32 value;
 171
 172         /* find start burst */
 173         for (i = len = 0; i < count * 32; i++) {
 174                 bit = getbit(samples,i);
 175                 if (bit) {
 176                         len++;
 177                 } else {
 178                         if (len >= 29)
 179                                 break;
 180                         len = 0;
 181                 }
 182         }
 183
 184         /* start burst to short */
 185         if (len < 29)
 186                 return 0xffffffff;
 187
 188         /* find start silence */
 189         for (len = 0; i < count * 32; i++) {
 190                 bit = getbit(samples,i);
 191                 if (bit) {
 192                         break;
 193                 } else {
 194                         len++;
 195                 }
 196         }
 197
 198         /* silence to short */
 199         if (len < 7)
 200                 return 0xffffffff;
 201
 202         /* go decoding */
 203         len   = 0;
 204         last = 1;
 205         value = 0; curBit = 1;
 206         for (; i < count * 32; i++) {
 207                 bit  = getbit(samples,i);
 208                 if (last) {
 209                         if(bit) {
 210                                 continue;
 211                         } else {
 212                                 len = 1;
 213                         }
 214                 } else {
 215                         if (bit) {
 216                                 if (len > (low + high) /2)
 217                                         value |= curBit;
 218                                 curBit <<= 1;
 219                                 if (curBit == 1)
 220                                         break;
 221                         } else {
 222                                 len++;
 223                         }
 224                 }
 225                 last = bit;
 226         }
 227
 228         return value;
 229 }
 230 EXPORT_SYMBOL_GPL(ir_decode_pulsedistance);
 231
 232 /* decode raw samples, biphase coding, used by rc5 for example */
 233 int ir_decode_biphase(u32 *samples, int count, int low, int high)
 234 {
 235         int i,last,bit,len,flips;
 236         u32 value;
 237
 238         /* find start bit (1) */
 239         for (i = 0; i < 32; i++) {
 240                 bit = getbit(samples,i);
 241                 if (bit)
 242                         break;
 243         }
 244
 245         /* go decoding */
 246         len   = 0;
 247         flips = 0;
 248         value = 1;
 249         for (; i < count * 32; i++) {
 250                 if (len > high)
 251                         break;
 252                 if (flips > 1)
 253                         break;
 254                 last = bit;
 255                 bit  = getbit(samples,i);
 256                 if (last == bit) {
 257                         len++;
 258                         continue;
 259                 }
 260                 if (len < low) {
 261                         len++;
 262                         flips++;
 263                         continue;
 264                 }
 265                 value <<= 1;
 266                 value |= bit;
 267                 flips = 0;
 268                 len   = 1;
 269         }
 270         return value;
 271 }
 272 EXPORT_SYMBOL_GPL(ir_decode_biphase);
 273
 274 /* RC5 decoding stuff, moved from bttv-input.c to share it with
 275  * saa7134 */
 276
 277 /* decode raw bit pattern to RC5 code */
 278 static u32 ir_rc5_decode(unsigned int code)
 279 {
 280         unsigned int org_code = code;
 281         unsigned int pair;
 282         unsigned int rc5 = 0;
 283         int i;
 284
 285         for (i = 0; i < 14; ++i) {
 286                 pair = code & 0x3;
 287                 code >>= 2;
 288
 289                 rc5 <<= 1;
 290                 switch (pair) {
 291                 case 0:
 292                 case 2:
 293                         break;
 294                 case 1:
 295                         rc5 |= 1;
 296                         break;
 297                 case 3:
 298                         dprintk(1, "ir-common: ir_rc5_decode(%x) bad code\n", org_code);
 299                         return 0;
 300                 }
 301         }
 302         dprintk(1, "ir-common: code=%x, rc5=%x, start=%x, toggle=%x, address=%x, "
 303                 "instr=%x\n", rc5, org_code, RC5_START(rc5),
 304                 RC5_TOGGLE(rc5), RC5_ADDR(rc5), RC5_INSTR(rc5));
 305         return rc5;
 306 }
 307
 308 void ir_rc5_timer_end(unsigned long data)
 309 {
 310         struct card_ir *ir = (struct card_ir *)data;
 311         struct timeval tv;
 312         unsigned long current_jiffies, timeout;
 313         u32 gap;
 314         u32 rc5 = 0;
 315
 316         /* get time */
 317         current_jiffies = jiffies;
 318         do_gettimeofday(&tv);
 319
 320         /* avoid overflow with gap >1s */
 321         if (tv.tv_sec - ir->base_time.tv_sec > 1) {
 322                 gap = 200000;
 323         } else {
 324                 gap = 1000000 * (tv.tv_sec - ir->base_time.tv_sec) +
 325                     tv.tv_usec - ir->base_time.tv_usec;
 326         }
 327
 328         /* signal we're ready to start a new code */
 329         ir->active = 0;
 330
 331         /* Allow some timer jitter (RC5 is ~24ms anyway so this is ok) */
 332         if (gap < 28000) {
 333                 dprintk(1, "ir-common: spurious timer_end\n");
 334                 return;
 335         }
 336
 337         if (ir->last_bit < 20) {
 338                 /* ignore spurious codes (caused by light/other remotes) */
 339                 dprintk(1, "ir-common: short code: %x\n", ir->code);
 340         } else {
 341                 ir->code = (ir->code << ir->shift_by) | 1;
 342                 rc5 = ir_rc5_decode(ir->code);
 343
 344                 /* two start bits? */
 345                 if (RC5_START(rc5) != ir->start) {
 346                         dprintk(1, "ir-common: rc5 start bits invalid: %u\n", RC5_START(rc5));
 347
 348                         /* right address? */
 349                 } else if (RC5_ADDR(rc5) == ir->addr) {
 350                         u32 toggle = RC5_TOGGLE(rc5);
 351                         u32 instr = RC5_INSTR(rc5);
 352
 353                         /* Good code, decide if repeat/repress */
 354                         if (toggle != RC5_TOGGLE(ir->last_rc5) ||
 355                             instr != RC5_INSTR(ir->last_rc5)) {
 356                                 dprintk(1, "ir-common: instruction %x, toggle %x\n", instr,
 357                                         toggle);
 358                                 ir_input_nokey(ir->dev, &ir->ir);
 359                                 ir_input_keydown(ir->dev, &ir->ir, instr,
 360                                                  instr);
 361                         }
 362
 363                         /* Set/reset key-up timer */
 364                         timeout = current_jiffies +
 365                                   msecs_to_jiffies(ir->rc5_key_timeout);
 366                         mod_timer(&ir->timer_keyup, timeout);
 367
 368                         /* Save code for repeat test */
 369                         ir->last_rc5 = rc5;
 370                 }
 371         }
 372 }
 373 EXPORT_SYMBOL_GPL(ir_rc5_timer_end);
 374
 375 void ir_rc5_timer_keyup(unsigned long data)
 376 {
 377         struct card_ir *ir = (struct card_ir *)data;
 378
 379         dprintk(1, "ir-common: key released\n");
 380         ir_input_nokey(ir->dev, &ir->ir);
 381 }
 382 EXPORT_SYMBOL_GPL(ir_rc5_timer_keyup);