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/moduleparam.h>
  25 #include <linux/string.h>
  26 #include <linux/jiffies.h>
  27 #include <media/ir-common.h>
  28
  29 /* -------------------------------------------------------------------------- */
  30
  31 MODULE_AUTHOR("Gerd Knorr <kraxel@bytesex.org> [SuSE Labs]");
  32 MODULE_LICENSE("GPL");
  33
  34 static int repeat = 1;
  35 module_param(repeat, int, 0444);
  36 MODULE_PARM_DESC(repeat,"auto-repeat for IR keys (default: on)");
  37
  38 static int debug = 0;    /* debug level (0,1,2) */
  39 module_param(debug, int, 0644);
  40
  41 #define dprintk(level, fmt, arg...)     if (debug >= level) \
  42         printk(KERN_DEBUG fmt , ## arg)
  43
  44 /* -------------------------------------------------------------------------- */
  45
  46 static void ir_input_key_event(struct input_dev *dev, struct ir_input_state *ir)
  47 {
  48         if (KEY_RESERVED == ir->keycode) {
  49                 printk(KERN_INFO "%s: unknown key: key=0x%02x raw=0x%02x down=%d\n",
  50                        dev->name,ir->ir_key,ir->ir_raw,ir->keypressed);
  51                 return;
  52         }
  53         dprintk(1,"%s: key event code=%d down=%d\n",
  54                 dev->name,ir->keycode,ir->keypressed);
  55         input_report_key(dev,ir->keycode,ir->keypressed);
  56         input_sync(dev);
  57 }
  58
  59 /* -------------------------------------------------------------------------- */
  60
  61 void ir_input_init(struct input_dev *dev, struct ir_input_state *ir,
  62                    int ir_type, IR_KEYTAB_TYPE *ir_codes)
  63 {
  64         int i;
  65
  66         ir->ir_type = ir_type;
  67         if (ir_codes)
  68                 memcpy(ir->ir_codes, ir_codes, sizeof(ir->ir_codes));
  69
  70
  71         dev->keycode     = ir->ir_codes;
  72         dev->keycodesize = sizeof(IR_KEYTAB_TYPE);
  73         dev->keycodemax  = IR_KEYTAB_SIZE;
  74         for (i = 0; i < IR_KEYTAB_SIZE; i++)
  75                 set_bit(ir->ir_codes[i], dev->keybit);
  76         clear_bit(0, dev->keybit);
  77
  78         set_bit(EV_KEY, dev->evbit);
  79         if (repeat)
  80                 set_bit(EV_REP, dev->evbit);
  81 }
  82
  83 void ir_input_nokey(struct input_dev *dev, struct ir_input_state *ir)
  84 {
  85         if (ir->keypressed) {
  86                 ir->keypressed = 0;
  87                 ir_input_key_event(dev,ir);
  88         }
  89 }
  90
  91 void ir_input_keydown(struct input_dev *dev, struct ir_input_state *ir,
  92                       u32 ir_key, u32 ir_raw)
  93 {
  94         u32 keycode = IR_KEYCODE(ir->ir_codes, ir_key);
  95
  96         if (ir->keypressed && ir->keycode != keycode) {
  97                 ir->keypressed = 0;
  98                 ir_input_key_event(dev,ir);
  99         }
 100         if (!ir->keypressed) {
 101                 ir->ir_key  = ir_key;
 102                 ir->ir_raw  = ir_raw;
 103                 ir->keycode = keycode;
 104                 ir->keypressed = 1;
 105                 ir_input_key_event(dev,ir);
 106         }
 107 }
 108
 109 /* -------------------------------------------------------------------------- */
 110 /* extract mask bits out of data and pack them into the result */
 111 u32 ir_extract_bits(u32 data, u32 mask)
 112 {
 113         u32 vbit = 1, value = 0;
 114
 115         do {
 116             if (mask&1) {
 117                 if (data&1)
 118                         value |= vbit;
 119                 vbit<<=1;
 120             }
 121             data>>=1;
 122         } while (mask>>=1);
 123
 124         return value;
 125 }
 126
 127 static int inline getbit(u32 *samples, int bit)
 128 {
 129         return (samples[bit/32] & (1 << (31-(bit%32)))) ? 1 : 0;
 130 }
 131
 132 /* sump raw samples for visual debugging ;) */
 133 int ir_dump_samples(u32 *samples, int count)
 134 {
 135         int i, bit, start;
 136
 137         printk(KERN_DEBUG "ir samples: ");
 138         start = 0;
 139         for (i = 0; i < count * 32; i++) {
 140                 bit = getbit(samples,i);
 141                 if (bit)
 142                         start = 1;
 143                 if (0 == start)
 144                         continue;
 145                 printk("%s", bit ? "#" : "_");
 146         }
 147         printk("\n");
 148         return 0;
 149 }
 150
 151 /* decode raw samples, pulse distance coding used by NEC remotes */
 152 int ir_decode_pulsedistance(u32 *samples, int count, int low, int high)
 153 {
 154         int i,last,bit,len;
 155         u32 curBit;
 156         u32 value;
 157
 158         /* find start burst */
 159         for (i = len = 0; i < count * 32; i++) {
 160                 bit = getbit(samples,i);
 161                 if (bit) {
 162                         len++;
 163                 } else {
 164                         if (len >= 29)
 165                                 break;
 166                         len = 0;
 167                 }
 168         }
 169
 170         /* start burst to short */
 171         if (len < 29)
 172                 return 0xffffffff;
 173
 174         /* find start silence */
 175         for (len = 0; i < count * 32; i++) {
 176                 bit = getbit(samples,i);
 177                 if (bit) {
 178                         break;
 179                 } else {
 180                         len++;
 181                 }
 182         }
 183
 184         /* silence to short */
 185         if (len < 7)
 186                 return 0xffffffff;
 187
 188         /* go decoding */
 189         len   = 0;
 190         last = 1;
 191         value = 0; curBit = 1;
 192         for (; i < count * 32; i++) {
 193                 bit  = getbit(samples,i);
 194                 if (last) {
 195                         if(bit) {
 196                                 continue;
 197                         } else {
 198                                 len = 1;
 199                         }
 200                 } else {
 201                         if (bit) {
 202                                 if (len > (low + high) /2)
 203                                         value |= curBit;
 204                                 curBit <<= 1;
 205                                 if (curBit == 1)
 206                                         break;
 207                         } else {
 208                                 len++;
 209                         }
 210                 }
 211                 last = bit;
 212         }
 213
 214         return value;
 215 }
 216
 217 /* decode raw samples, biphase coding, used by rc5 for example */
 218 int ir_decode_biphase(u32 *samples, int count, int low, int high)
 219 {
 220         int i,last,bit,len,flips;
 221         u32 value;
 222
 223         /* find start bit (1) */
 224         for (i = 0; i < 32; i++) {
 225                 bit = getbit(samples,i);
 226                 if (bit)
 227                         break;
 228         }
 229
 230         /* go decoding */
 231         len   = 0;
 232         flips = 0;
 233         value = 1;
 234         for (; i < count * 32; i++) {
 235                 if (len > high)
 236                         break;
 237                 if (flips > 1)
 238                         break;
 239                 last = bit;
 240                 bit  = getbit(samples,i);
 241                 if (last == bit) {
 242                         len++;
 243                         continue;
 244                 }
 245                 if (len < low) {
 246                         len++;
 247                         flips++;
 248                         continue;
 249                 }
 250                 value <<= 1;
 251                 value |= bit;
 252                 flips = 0;
 253                 len   = 1;
 254         }
 255         return value;
 256 }
 257
 258 /* RC5 decoding stuff, moved from bttv-input.c to share it with
 259  * saa7134 */
 260
 261 /* decode raw bit pattern to RC5 code */
 262 u32 ir_rc5_decode(unsigned int code)
 263 {
 264         unsigned int org_code = code;
 265         unsigned int pair;
 266         unsigned int rc5 = 0;
 267         int i;
 268
 269         for (i = 0; i < 14; ++i) {
 270                 pair = code & 0x3;
 271                 code >>= 2;
 272
 273                 rc5 <<= 1;
 274                 switch (pair) {
 275                 case 0:
 276                 case 2:
 277                         break;
 278                 case 1:
 279                         rc5 |= 1;
 280                         break;
 281                 case 3:
 282                         dprintk(1, "ir-common: ir_rc5_decode(%x) bad code\n", org_code);
 283                         return 0;
 284                 }
 285         }
 286         dprintk(1, "ir-common: code=%x, rc5=%x, start=%x, toggle=%x, address=%x, "
 287                 "instr=%x\n", rc5, org_code, RC5_START(rc5),
 288                 RC5_TOGGLE(rc5), RC5_ADDR(rc5), RC5_INSTR(rc5));
 289         return rc5;
 290 }
 291
 292 void ir_rc5_timer_end(unsigned long data)
 293 {
 294         struct card_ir *ir = (struct card_ir *)data;
 295         struct timeval tv;
 296         unsigned long current_jiffies, timeout;
 297         u32 gap;
 298         u32 rc5 = 0;
 299
 300         /* get time */
 301         current_jiffies = jiffies;
 302         do_gettimeofday(&tv);
 303
 304         /* avoid overflow with gap >1s */
 305         if (tv.tv_sec - ir->base_time.tv_sec > 1) {
 306                 gap = 200000;
 307         } else {
 308                 gap = 1000000 * (tv.tv_sec - ir->base_time.tv_sec) +
 309                     tv.tv_usec - ir->base_time.tv_usec;
 310         }
 311
 312         /* signal we're ready to start a new code */
 313         ir->active = 0;
 314
 315         /* Allow some timer jitter (RC5 is ~24ms anyway so this is ok) */
 316         if (gap < 28000) {
 317                 dprintk(1, "ir-common: spurious timer_end\n");
 318                 return;
 319         }
 320
 321         if (ir->last_bit < 20) {
 322                 /* ignore spurious codes (caused by light/other remotes) */
 323                 dprintk(1, "ir-common: short code: %x\n", ir->code);
 324         } else {
 325                 ir->code = (ir->code << ir->shift_by) | 1;
 326                 rc5 = ir_rc5_decode(ir->code);
 327
 328                 /* two start bits? */
 329                 if (RC5_START(rc5) != ir->start) {
 330                         dprintk(1, "ir-common: rc5 start bits invalid: %u\n", RC5_START(rc5));
 331
 332                         /* right address? */
 333                 } else if (RC5_ADDR(rc5) == ir->addr) {
 334                         u32 toggle = RC5_TOGGLE(rc5);
 335                         u32 instr = RC5_INSTR(rc5);
 336
 337                         /* Good code, decide if repeat/repress */
 338                         if (toggle != RC5_TOGGLE(ir->last_rc5) ||
 339                             instr != RC5_INSTR(ir->last_rc5)) {
 340                                 dprintk(1, "ir-common: instruction %x, toggle %x\n", instr,
 341                                         toggle);
 342                                 ir_input_nokey(ir->dev, &ir->ir);
 343                                 ir_input_keydown(ir->dev, &ir->ir, instr,
 344                                                  instr);
 345                         }
 346
 347                         /* Set/reset key-up timer */
 348                         timeout = current_jiffies +
 349                                   msecs_to_jiffies(ir->rc5_key_timeout);
 350                         mod_timer(&ir->timer_keyup, timeout);
 351
 352                         /* Save code for repeat test */
 353                         ir->last_rc5 = rc5;
 354                 }
 355         }
 356 }
 357
 358 void ir_rc5_timer_keyup(unsigned long data)
 359 {
 360         struct card_ir *ir = (struct card_ir *)data;
 361
 362         dprintk(1, "ir-common: key released\n");
 363         ir_input_nokey(ir->dev, &ir->ir);
 364 }
 365
 366 EXPORT_SYMBOL_GPL(ir_input_init);
 367 EXPORT_SYMBOL_GPL(ir_input_nokey);
 368 EXPORT_SYMBOL_GPL(ir_input_keydown);
 369
 370 EXPORT_SYMBOL_GPL(ir_extract_bits);
 371 EXPORT_SYMBOL_GPL(ir_dump_samples);
 372 EXPORT_SYMBOL_GPL(ir_decode_biphase);
 373 EXPORT_SYMBOL_GPL(ir_decode_pulsedistance);
 374
 375 EXPORT_SYMBOL_GPL(ir_rc5_decode);
 376 EXPORT_SYMBOL_GPL(ir_rc5_timer_end);
 377 EXPORT_SYMBOL_GPL(ir_rc5_timer_keyup);
 378
 379 /*
 380  * Local variables:
 381  * c-basic-offset: 8
 382  * End:
 383  */