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 = 0;    /* 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, IR_KEYTAB_TYPE *ir_codes)
  62 {
  63         int i;
  64
  65         ir->ir_type = ir_type;
  66         if (ir_codes)
  67                 memcpy(ir->ir_codes, ir_codes, sizeof(ir->ir_codes));
  68
  69
  70         dev->keycode     = ir->ir_codes;
  71         dev->keycodesize = sizeof(IR_KEYTAB_TYPE);
  72         dev->keycodemax  = IR_KEYTAB_SIZE;
  73         for (i = 0; i < IR_KEYTAB_SIZE; i++)
  74                 set_bit(ir->ir_codes[i], dev->keybit);
  75         clear_bit(0, dev->keybit);
  76
  77         set_bit(EV_KEY, dev->evbit);
  78         if (repeat)
  79                 set_bit(EV_REP, dev->evbit);
  80 }
  81
  82 void ir_input_nokey(struct input_dev *dev, struct ir_input_state *ir)
  83 {
  84         if (ir->keypressed) {
  85                 ir->keypressed = 0;
  86                 ir_input_key_event(dev,ir);
  87         }
  88 }
  89
  90 void ir_input_keydown(struct input_dev *dev, struct ir_input_state *ir,
  91                       u32 ir_key, u32 ir_raw)
  92 {
  93         u32 keycode = IR_KEYCODE(ir->ir_codes, ir_key);
  94
  95         if (ir->keypressed && ir->keycode != keycode) {
  96                 ir->keypressed = 0;
  97                 ir_input_key_event(dev,ir);
  98         }
  99         if (!ir->keypressed) {
 100                 ir->ir_key  = ir_key;
 101                 ir->ir_raw  = ir_raw;
 102                 ir->keycode = keycode;
 103                 ir->keypressed = 1;
 104                 ir_input_key_event(dev,ir);
 105         }
 106 }
 107
 108 /* -------------------------------------------------------------------------- */
 109 /* extract mask bits out of data and pack them into the result */
 110 u32 ir_extract_bits(u32 data, u32 mask)
 111 {
 112         u32 vbit = 1, value = 0;
 113
 114         do {
 115             if (mask&1) {
 116                 if (data&1)
 117                         value |= vbit;
 118                 vbit<<=1;
 119             }
 120             data>>=1;
 121         } while (mask>>=1);
 122
 123         return value;
 124 }
 125
 126 static int inline getbit(u32 *samples, int bit)
 127 {
 128         return (samples[bit/32] & (1 << (31-(bit%32)))) ? 1 : 0;
 129 }
 130
 131 /* sump raw samples for visual debugging ;) */
 132 int ir_dump_samples(u32 *samples, int count)
 133 {
 134         int i, bit, start;
 135
 136         printk(KERN_DEBUG "ir samples: ");
 137         start = 0;
 138         for (i = 0; i < count * 32; i++) {
 139                 bit = getbit(samples,i);
 140                 if (bit)
 141                         start = 1;
 142                 if (0 == start)
 143                         continue;
 144                 printk("%s", bit ? "#" : "_");
 145         }
 146         printk("\n");
 147         return 0;
 148 }
 149
 150 /* decode raw samples, pulse distance coding used by NEC remotes */
 151 int ir_decode_pulsedistance(u32 *samples, int count, int low, int high)
 152 {
 153         int i,last,bit,len;
 154         u32 curBit;
 155         u32 value;
 156
 157         /* find start burst */
 158         for (i = len = 0; i < count * 32; i++) {
 159                 bit = getbit(samples,i);
 160                 if (bit) {
 161                         len++;
 162                 } else {
 163                         if (len >= 29)
 164                                 break;
 165                         len = 0;
 166                 }
 167         }
 168
 169         /* start burst to short */
 170         if (len < 29)
 171                 return 0xffffffff;
 172
 173         /* find start silence */
 174         for (len = 0; i < count * 32; i++) {
 175                 bit = getbit(samples,i);
 176                 if (bit) {
 177                         break;
 178                 } else {
 179                         len++;
 180                 }
 181         }
 182
 183         /* silence to short */
 184         if (len < 7)
 185                 return 0xffffffff;
 186
 187         /* go decoding */
 188         len   = 0;
 189         last = 1;
 190         value = 0; curBit = 1;
 191         for (; i < count * 32; i++) {
 192                 bit  = getbit(samples,i);
 193                 if (last) {
 194                         if(bit) {
 195                                 continue;
 196                         } else {
 197                                 len = 1;
 198                         }
 199                 } else {
 200                         if (bit) {
 201                                 if (len > (low + high) /2)
 202                                         value |= curBit;
 203                                 curBit <<= 1;
 204                                 if (curBit == 1)
 205                                         break;
 206                         } else {
 207                                 len++;
 208                         }
 209                 }
 210                 last = bit;
 211         }
 212
 213         return value;
 214 }
 215
 216 /* decode raw samples, biphase coding, used by rc5 for example */
 217 int ir_decode_biphase(u32 *samples, int count, int low, int high)
 218 {
 219         int i,last,bit,len,flips;
 220         u32 value;
 221
 222         /* find start bit (1) */
 223         for (i = 0; i < 32; i++) {
 224                 bit = getbit(samples,i);
 225                 if (bit)
 226                         break;
 227         }
 228
 229         /* go decoding */
 230         len   = 0;
 231         flips = 0;
 232         value = 1;
 233         for (; i < count * 32; i++) {
 234                 if (len > high)
 235                         break;
 236                 if (flips > 1)
 237                         break;
 238                 last = bit;
 239                 bit  = getbit(samples,i);
 240                 if (last == bit) {
 241                         len++;
 242                         continue;
 243                 }
 244                 if (len < low) {
 245                         len++;
 246                         flips++;
 247                         continue;
 248                 }
 249                 value <<= 1;
 250                 value |= bit;
 251                 flips = 0;
 252                 len   = 1;
 253         }
 254         return value;
 255 }
 256
 257 /* RC5 decoding stuff, moved from bttv-input.c to share it with
 258  * saa7134 */
 259
 260 /* decode raw bit pattern to RC5 code */
 261 static u32 ir_rc5_decode(unsigned int code)
 262 {
 263         unsigned int org_code = code;
 264         unsigned int pair;
 265         unsigned int rc5 = 0;
 266         int i;
 267
 268         for (i = 0; i < 14; ++i) {
 269                 pair = code & 0x3;
 270                 code >>= 2;
 271
 272                 rc5 <<= 1;
 273                 switch (pair) {
 274                 case 0:
 275                 case 2:
 276                         break;
 277                 case 1:
 278                         rc5 |= 1;
 279                         break;
 280                 case 3:
 281                         dprintk(1, "ir-common: ir_rc5_decode(%x) bad code\n", org_code);
 282                         return 0;
 283                 }
 284         }
 285         dprintk(1, "ir-common: code=%x, rc5=%x, start=%x, toggle=%x, address=%x, "
 286                 "instr=%x\n", rc5, org_code, RC5_START(rc5),
 287                 RC5_TOGGLE(rc5), RC5_ADDR(rc5), RC5_INSTR(rc5));
 288         return rc5;
 289 }
 290
 291 void ir_rc5_timer_end(unsigned long data)
 292 {
 293         struct card_ir *ir = (struct card_ir *)data;
 294         struct timeval tv;
 295         unsigned long current_jiffies, timeout;
 296         u32 gap;
 297         u32 rc5 = 0;
 298
 299         /* get time */
 300         current_jiffies = jiffies;
 301         do_gettimeofday(&tv);
 302
 303         /* avoid overflow with gap >1s */
 304         if (tv.tv_sec - ir->base_time.tv_sec > 1) {
 305                 gap = 200000;
 306         } else {
 307                 gap = 1000000 * (tv.tv_sec - ir->base_time.tv_sec) +
 308                     tv.tv_usec - ir->base_time.tv_usec;
 309         }
 310
 311         /* signal we're ready to start a new code */
 312         ir->active = 0;
 313
 314         /* Allow some timer jitter (RC5 is ~24ms anyway so this is ok) */
 315         if (gap < 28000) {
 316                 dprintk(1, "ir-common: spurious timer_end\n");
 317                 return;
 318         }
 319
 320         if (ir->last_bit < 20) {
 321                 /* ignore spurious codes (caused by light/other remotes) */
 322                 dprintk(1, "ir-common: short code: %x\n", ir->code);
 323         } else {
 324                 ir->code = (ir->code << ir->shift_by) | 1;
 325                 rc5 = ir_rc5_decode(ir->code);
 326
 327                 /* two start bits? */
 328                 if (RC5_START(rc5) != ir->start) {
 329                         dprintk(1, "ir-common: rc5 start bits invalid: %u\n", RC5_START(rc5));
 330
 331                         /* right address? */
 332                 } else if (RC5_ADDR(rc5) == ir->addr) {
 333                         u32 toggle = RC5_TOGGLE(rc5);
 334                         u32 instr = RC5_INSTR(rc5);
 335
 336                         /* Good code, decide if repeat/repress */
 337                         if (toggle != RC5_TOGGLE(ir->last_rc5) ||
 338                             instr != RC5_INSTR(ir->last_rc5)) {
 339                                 dprintk(1, "ir-common: instruction %x, toggle %x\n", instr,
 340                                         toggle);
 341                                 ir_input_nokey(ir->dev, &ir->ir);
 342                                 ir_input_keydown(ir->dev, &ir->ir, instr,
 343                                                  instr);
 344                         }
 345
 346                         /* Set/reset key-up timer */
 347                         timeout = current_jiffies +
 348                                   msecs_to_jiffies(ir->rc5_key_timeout);
 349                         mod_timer(&ir->timer_keyup, timeout);
 350
 351                         /* Save code for repeat test */
 352                         ir->last_rc5 = rc5;
 353                 }
 354         }
 355 }
 356
 357 void ir_rc5_timer_keyup(unsigned long data)
 358 {
 359         struct card_ir *ir = (struct card_ir *)data;
 360
 361         dprintk(1, "ir-common: key released\n");
 362         ir_input_nokey(ir->dev, &ir->ir);
 363 }
 364
 365 EXPORT_SYMBOL_GPL(ir_input_init);
 366 EXPORT_SYMBOL_GPL(ir_input_nokey);
 367 EXPORT_SYMBOL_GPL(ir_input_keydown);
 368
 369 EXPORT_SYMBOL_GPL(ir_extract_bits);
 370 EXPORT_SYMBOL_GPL(ir_dump_samples);
 371 EXPORT_SYMBOL_GPL(ir_decode_biphase);
 372 EXPORT_SYMBOL_GPL(ir_decode_pulsedistance);
 373
 374 EXPORT_SYMBOL_GPL(ir_rc5_timer_end);
 375 EXPORT_SYMBOL_GPL(ir_rc5_timer_keyup);
 376
 377 /*
 378  * Local variables:
 379  * c-basic-offset: 8
 380  * End:
 381  */