drivers/media/IR/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 /* -------------------------------------------------------------------------- */
  38
  39 static void ir_input_key_event(struct input_dev *dev, struct ir_input_state *ir)
  40 {
  41         if (KEY_RESERVED == ir->keycode) {
  42                 printk(KERN_INFO "%s: unknown key: key=0x%02x down=%d\n",
  43                        dev->name, ir->ir_key, ir->keypressed);
  44                 return;
  45         }
  46         IR_dprintk(1,"%s: key event code=%d down=%d\n",
  47                 dev->name,ir->keycode,ir->keypressed);
  48         input_report_key(dev,ir->keycode,ir->keypressed);
  49         input_sync(dev);
  50 }
  51
  52 /* -------------------------------------------------------------------------- */
  53
  54 int ir_input_init(struct input_dev *dev, struct ir_input_state *ir,
  55                   const u64 ir_type)
  56 {
  57         ir->ir_type = ir_type;
  58
  59         if (repeat)
  60                 set_bit(EV_REP, dev->evbit);
  61
  62         return 0;
  63 }
  64 EXPORT_SYMBOL_GPL(ir_input_init);
  65
  66
  67 void ir_input_nokey(struct input_dev *dev, struct ir_input_state *ir)
  68 {
  69         if (ir->keypressed) {
  70                 ir->keypressed = 0;
  71                 ir_input_key_event(dev,ir);
  72         }
  73 }
  74 EXPORT_SYMBOL_GPL(ir_input_nokey);
  75
  76 void ir_input_keydown(struct input_dev *dev, struct ir_input_state *ir,
  77                       u32 ir_key)
  78 {
  79         u32 keycode = ir_g_keycode_from_table(dev, ir_key);
  80
  81         if (ir->keypressed && ir->keycode != keycode) {
  82                 ir->keypressed = 0;
  83                 ir_input_key_event(dev,ir);
  84         }
  85         if (!ir->keypressed) {
  86                 ir->ir_key  = ir_key;
  87                 ir->keycode = keycode;
  88                 ir->keypressed = 1;
  89                 ir_input_key_event(dev,ir);
  90         }
  91 }
  92 EXPORT_SYMBOL_GPL(ir_input_keydown);
  93
  94 /* -------------------------------------------------------------------------- */
  95 /* extract mask bits out of data and pack them into the result */
  96 u32 ir_extract_bits(u32 data, u32 mask)
  97 {
  98         u32 vbit = 1, value = 0;
  99
 100         do {
 101             if (mask&1) {
 102                 if (data&1)
 103                         value |= vbit;
 104                 vbit<<=1;
 105             }
 106             data>>=1;
 107         } while (mask>>=1);
 108
 109         return value;
 110 }
 111 EXPORT_SYMBOL_GPL(ir_extract_bits);
 112
 113 static int inline getbit(u32 *samples, int bit)
 114 {
 115         return (samples[bit/32] & (1 << (31-(bit%32)))) ? 1 : 0;
 116 }
 117
 118 /* sump raw samples for visual debugging ;) */
 119 int ir_dump_samples(u32 *samples, int count)
 120 {
 121         int i, bit, start;
 122
 123         printk(KERN_DEBUG "ir samples: ");
 124         start = 0;
 125         for (i = 0; i < count * 32; i++) {
 126                 bit = getbit(samples,i);
 127                 if (bit)
 128                         start = 1;
 129                 if (0 == start)
 130                         continue;
 131                 printk("%s", bit ? "#" : "_");
 132         }
 133         printk("\n");
 134         return 0;
 135 }
 136 EXPORT_SYMBOL_GPL(ir_dump_samples);
 137
 138 /* decode raw samples, pulse distance coding used by NEC remotes */
 139 int ir_decode_pulsedistance(u32 *samples, int count, int low, int high)
 140 {
 141         int i,last,bit,len;
 142         u32 curBit;
 143         u32 value;
 144
 145         /* find start burst */
 146         for (i = len = 0; i < count * 32; i++) {
 147                 bit = getbit(samples,i);
 148                 if (bit) {
 149                         len++;
 150                 } else {
 151                         if (len >= 29)
 152                                 break;
 153                         len = 0;
 154                 }
 155         }
 156
 157         /* start burst to short */
 158         if (len < 29)
 159                 return 0xffffffff;
 160
 161         /* find start silence */
 162         for (len = 0; i < count * 32; i++) {
 163                 bit = getbit(samples,i);
 164                 if (bit) {
 165                         break;
 166                 } else {
 167                         len++;
 168                 }
 169         }
 170
 171         /* silence to short */
 172         if (len < 7)
 173                 return 0xffffffff;
 174
 175         /* go decoding */
 176         len   = 0;
 177         last = 1;
 178         value = 0; curBit = 1;
 179         for (; i < count * 32; i++) {
 180                 bit  = getbit(samples,i);
 181                 if (last) {
 182                         if(bit) {
 183                                 continue;
 184                         } else {
 185                                 len = 1;
 186                         }
 187                 } else {
 188                         if (bit) {
 189                                 if (len > (low + high) /2)
 190                                         value |= curBit;
 191                                 curBit <<= 1;
 192                                 if (curBit == 1)
 193                                         break;
 194                         } else {
 195                                 len++;
 196                         }
 197                 }
 198                 last = bit;
 199         }
 200
 201         return value;
 202 }
 203 EXPORT_SYMBOL_GPL(ir_decode_pulsedistance);
 204
 205 /* decode raw samples, biphase coding, used by rc5 for example */
 206 int ir_decode_biphase(u32 *samples, int count, int low, int high)
 207 {
 208         int i,last,bit,len,flips;
 209         u32 value;
 210
 211         /* find start bit (1) */
 212         for (i = 0; i < 32; i++) {
 213                 bit = getbit(samples,i);
 214                 if (bit)
 215                         break;
 216         }
 217
 218         /* go decoding */
 219         len   = 0;
 220         flips = 0;
 221         value = 1;
 222         for (; i < count * 32; i++) {
 223                 if (len > high)
 224                         break;
 225                 if (flips > 1)
 226                         break;
 227                 last = bit;
 228                 bit  = getbit(samples,i);
 229                 if (last == bit) {
 230                         len++;
 231                         continue;
 232                 }
 233                 if (len < low) {
 234                         len++;
 235                         flips++;
 236                         continue;
 237                 }
 238                 value <<= 1;
 239                 value |= bit;
 240                 flips = 0;
 241                 len   = 1;
 242         }
 243         return value;
 244 }
 245 EXPORT_SYMBOL_GPL(ir_decode_biphase);
 246
 247 /* RC5 decoding stuff, moved from bttv-input.c to share it with
 248  * saa7134 */
 249
 250 /* decode raw bit pattern to RC5 code */
 251 u32 ir_rc5_decode(unsigned int code)
 252 {
 253         unsigned int org_code = code;
 254         unsigned int pair;
 255         unsigned int rc5 = 0;
 256         int i;
 257
 258         for (i = 0; i < 14; ++i) {
 259                 pair = code & 0x3;
 260                 code >>= 2;
 261
 262                 rc5 <<= 1;
 263                 switch (pair) {
 264                 case 0:
 265                 case 2:
 266                         break;
 267                 case 1:
 268                         rc5 |= 1;
 269                         break;
 270                 case 3:
 271                         IR_dprintk(1, "ir-common: ir_rc5_decode(%x) bad code\n", org_code);
 272                         return 0;
 273                 }
 274         }
 275         IR_dprintk(1, "ir-common: code=%x, rc5=%x, start=%x, toggle=%x, address=%x, "
 276                 "instr=%x\n", rc5, org_code, RC5_START(rc5),
 277                 RC5_TOGGLE(rc5), RC5_ADDR(rc5), RC5_INSTR(rc5));
 278         return rc5;
 279 }
 280 EXPORT_SYMBOL_GPL(ir_rc5_decode);
 281
 282 void ir_rc5_timer_end(unsigned long data)
 283 {
 284         struct card_ir *ir = (struct card_ir *)data;
 285         struct timeval tv;
 286         unsigned long current_jiffies, timeout;
 287         u32 gap;
 288         u32 rc5 = 0;
 289
 290         /* get time */
 291         current_jiffies = jiffies;
 292         do_gettimeofday(&tv);
 293
 294         /* avoid overflow with gap >1s */
 295         if (tv.tv_sec - ir->base_time.tv_sec > 1) {
 296                 gap = 200000;
 297         } else {
 298                 gap = 1000000 * (tv.tv_sec - ir->base_time.tv_sec) +
 299                     tv.tv_usec - ir->base_time.tv_usec;
 300         }
 301
 302         /* signal we're ready to start a new code */
 303         ir->active = 0;
 304
 305         /* Allow some timer jitter (RC5 is ~24ms anyway so this is ok) */
 306         if (gap < 28000) {
 307                 IR_dprintk(1, "ir-common: spurious timer_end\n");
 308                 return;
 309         }
 310
 311         if (ir->last_bit < 20) {
 312                 /* ignore spurious codes (caused by light/other remotes) */
 313                 IR_dprintk(1, "ir-common: short code: %x\n", ir->code);
 314         } else {
 315                 ir->code = (ir->code << ir->shift_by) | 1;
 316                 rc5 = ir_rc5_decode(ir->code);
 317
 318                 /* two start bits? */
 319                 if (RC5_START(rc5) != ir->start) {
 320                         IR_dprintk(1, "ir-common: rc5 start bits invalid: %u\n", RC5_START(rc5));
 321
 322                         /* right address? */
 323                 } else if (RC5_ADDR(rc5) == ir->addr) {
 324                         u32 toggle = RC5_TOGGLE(rc5);
 325                         u32 instr = RC5_INSTR(rc5);
 326
 327                         /* Good code, decide if repeat/repress */
 328                         if (toggle != RC5_TOGGLE(ir->last_rc5) ||
 329                             instr != RC5_INSTR(ir->last_rc5)) {
 330                                 IR_dprintk(1, "ir-common: instruction %x, toggle %x\n", instr,
 331                                         toggle);
 332                                 ir_input_nokey(ir->dev, &ir->ir);
 333                                 ir_input_keydown(ir->dev, &ir->ir, instr);
 334                         }
 335
 336                         /* Set/reset key-up timer */
 337                         timeout = current_jiffies +
 338                                   msecs_to_jiffies(ir->rc5_key_timeout);
 339                         mod_timer(&ir->timer_keyup, timeout);
 340
 341                         /* Save code for repeat test */
 342                         ir->last_rc5 = rc5;
 343                 }
 344         }
 345 }
 346 EXPORT_SYMBOL_GPL(ir_rc5_timer_end);
 347
 348 void ir_rc5_timer_keyup(unsigned long data)
 349 {
 350         struct card_ir *ir = (struct card_ir *)data;
 351
 352         IR_dprintk(1, "ir-common: key released\n");
 353         ir_input_nokey(ir->dev, &ir->ir);
 354 }
 355 EXPORT_SYMBOL_GPL(ir_rc5_timer_keyup);