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
 111 u32 ir_extract_bits(u32 data, u32 mask)
 112 {
 113         int mbit, vbit;
 114         u32 value;
 115
 116         value = 0;
 117         vbit  = 0;
 118         for (mbit = 0; mbit < 32; mbit++) {
 119                 if (!(mask & ((u32)1 << mbit)))
 120                         continue;
 121                 if (data & ((u32)1 << mbit))
 122                         value |= (1 << vbit);
 123                 vbit++;
 124         }
 125         return value;
 126 }
 127
 128 static int inline getbit(u32 *samples, int bit)
 129 {
 130         return (samples[bit/32] & (1 << (31-(bit%32)))) ? 1 : 0;
 131 }
 132
 133 /* sump raw samples for visual debugging ;) */
 134 int ir_dump_samples(u32 *samples, int count)
 135 {
 136         int i, bit, start;
 137
 138         printk(KERN_DEBUG "ir samples: ");
 139         start = 0;
 140         for (i = 0; i < count * 32; i++) {
 141                 bit = getbit(samples,i);
 142                 if (bit)
 143                         start = 1;
 144                 if (0 == start)
 145                         continue;
 146                 printk("%s", bit ? "#" : "_");
 147         }
 148         printk("\n");
 149         return 0;
 150 }
 151
 152 /* decode raw samples, pulse distance coding used by NEC remotes */
 153 int ir_decode_pulsedistance(u32 *samples, int count, int low, int high)
 154 {
 155         int i,last,bit,len;
 156         u32 curBit;
 157         u32 value;
 158
 159         /* find start burst */
 160         for (i = len = 0; i < count * 32; i++) {
 161                 bit = getbit(samples,i);
 162                 if (bit) {
 163                         len++;
 164                 } else {
 165                         if (len >= 29)
 166                                 break;
 167                         len = 0;
 168                 }
 169         }
 170
 171         /* start burst to short */
 172         if (len < 29)
 173                 return 0xffffffff;
 174
 175         /* find start silence */
 176         for (len = 0; i < count * 32; i++) {
 177                 bit = getbit(samples,i);
 178                 if (bit) {
 179                         break;
 180                 } else {
 181                         len++;
 182                 }
 183         }
 184
 185         /* silence to short */
 186         if (len < 7)
 187                 return 0xffffffff;
 188
 189         /* go decoding */
 190         len   = 0;
 191         last = 1;
 192         value = 0; curBit = 1;
 193         for (; i < count * 32; i++) {
 194                 bit  = getbit(samples,i);
 195                 if (last) {
 196                         if(bit) {
 197                                 continue;
 198                         } else {
 199                                 len = 1;
 200                         }
 201                 } else {
 202                         if (bit) {
 203                                 if (len > (low + high) /2)
 204                                         value |= curBit;
 205                                 curBit <<= 1;
 206                                 if (curBit == 1)
 207                                         break;
 208                         } else {
 209                                 len++;
 210                         }
 211                 }
 212                 last = bit;
 213         }
 214
 215         return value;
 216 }
 217
 218 /* decode raw samples, biphase coding, used by rc5 for example */
 219 int ir_decode_biphase(u32 *samples, int count, int low, int high)
 220 {
 221         int i,last,bit,len,flips;
 222         u32 value;
 223
 224         /* find start bit (1) */
 225         for (i = 0; i < 32; i++) {
 226                 bit = getbit(samples,i);
 227                 if (bit)
 228                         break;
 229         }
 230
 231         /* go decoding */
 232         len   = 0;
 233         flips = 0;
 234         value = 1;
 235         for (; i < count * 32; i++) {
 236                 if (len > high)
 237                         break;
 238                 if (flips > 1)
 239                         break;
 240                 last = bit;
 241                 bit  = getbit(samples,i);
 242                 if (last == bit) {
 243                         len++;
 244                         continue;
 245                 }
 246                 if (len < low) {
 247                         len++;
 248                         flips++;
 249                         continue;
 250                 }
 251                 value <<= 1;
 252                 value |= bit;
 253                 flips = 0;
 254                 len   = 1;
 255         }
 256         return value;
 257 }
 258
 259 /* RC5 decoding stuff, moved from bttv-input.c to share it with
 260  * saa7134 */
 261
 262 /* decode raw bit pattern to RC5 code */
 263 u32 ir_rc5_decode(unsigned int code)
 264 {
 265         unsigned int org_code = code;
 266         unsigned int pair;
 267         unsigned int rc5 = 0;
 268         int i;
 269
 270         for (i = 0; i < 14; ++i) {
 271                 pair = code & 0x3;
 272                 code >>= 2;
 273
 274                 rc5 <<= 1;
 275                 switch (pair) {
 276                 case 0:
 277                 case 2:
 278                         break;
 279                 case 1:
 280                         rc5 |= 1;
 281                         break;
 282                 case 3:
 283                         dprintk(1, "ir-common: ir_rc5_decode(%x) bad code\n", org_code);
 284                         return 0;
 285                 }
 286         }
 287         dprintk(1, "ir-common: code=%x, rc5=%x, start=%x, toggle=%x, address=%x, "
 288                 "instr=%x\n", rc5, org_code, RC5_START(rc5),
 289                 RC5_TOGGLE(rc5), RC5_ADDR(rc5), RC5_INSTR(rc5));
 290         return rc5;
 291 }
 292
 293 void ir_rc5_timer_end(unsigned long data)
 294 {
 295         struct card_ir *ir = (struct card_ir *)data;
 296         struct timeval tv;
 297         unsigned long current_jiffies, timeout;
 298         u32 gap;
 299         u32 rc5 = 0;
 300
 301         /* get time */
 302         current_jiffies = jiffies;
 303         do_gettimeofday(&tv);
 304
 305         /* avoid overflow with gap >1s */
 306         if (tv.tv_sec - ir->base_time.tv_sec > 1) {
 307                 gap = 200000;
 308         } else {
 309                 gap = 1000000 * (tv.tv_sec - ir->base_time.tv_sec) +
 310                     tv.tv_usec - ir->base_time.tv_usec;
 311         }
 312
 313         /* signal we're ready to start a new code */
 314         ir->active = 0;
 315
 316         /* Allow some timer jitter (RC5 is ~24ms anyway so this is ok) */
 317         if (gap < 28000) {
 318                 dprintk(1, "ir-common: spurious timer_end\n");
 319                 return;
 320         }
 321
 322         if (ir->last_bit < 20) {
 323                 /* ignore spurious codes (caused by light/other remotes) */
 324                 dprintk(1, "ir-common: short code: %x\n", ir->code);
 325         } else {
 326                 ir->code = (ir->code << ir->shift_by) | 1;
 327                 rc5 = ir_rc5_decode(ir->code);
 328
 329                 /* two start bits? */
 330                 if (RC5_START(rc5) != ir->start) {
 331                         dprintk(1, "ir-common: rc5 start bits invalid: %u\n", RC5_START(rc5));
 332
 333                         /* right address? */
 334                 } else if (RC5_ADDR(rc5) == ir->addr) {
 335                         u32 toggle = RC5_TOGGLE(rc5);
 336                         u32 instr = RC5_INSTR(rc5);
 337
 338                         /* Good code, decide if repeat/repress */
 339                         if (toggle != RC5_TOGGLE(ir->last_rc5) ||
 340                             instr != RC5_INSTR(ir->last_rc5)) {
 341                                 dprintk(1, "ir-common: instruction %x, toggle %x\n", instr,
 342                                         toggle);
 343                                 ir_input_nokey(ir->dev, &ir->ir);
 344                                 ir_input_keydown(ir->dev, &ir->ir, instr,
 345                                                  instr);
 346                         }
 347
 348                         /* Set/reset key-up timer */
 349                         timeout = current_jiffies + (500 + ir->rc5_key_timeout
 350                                                      * HZ) / 1000;
 351                         mod_timer(&ir->timer_keyup, timeout);
 352
 353                         /* Save code for repeat test */
 354                         ir->last_rc5 = rc5;
 355                 }
 356         }
 357 }
 358
 359 void ir_rc5_timer_keyup(unsigned long data)
 360 {
 361         struct card_ir *ir = (struct card_ir *)data;
 362
 363         dprintk(1, "ir-common: key released\n");
 364         ir_input_nokey(ir->dev, &ir->ir);
 365 }
 366
 367 EXPORT_SYMBOL_GPL(ir_input_init);
 368 EXPORT_SYMBOL_GPL(ir_input_nokey);
 369 EXPORT_SYMBOL_GPL(ir_input_keydown);
 370
 371 EXPORT_SYMBOL_GPL(ir_extract_bits);
 372 EXPORT_SYMBOL_GPL(ir_dump_samples);
 373 EXPORT_SYMBOL_GPL(ir_decode_biphase);
 374 EXPORT_SYMBOL_GPL(ir_decode_pulsedistance);
 375
 376 EXPORT_SYMBOL_GPL(ir_rc5_decode);
 377 EXPORT_SYMBOL_GPL(ir_rc5_timer_end);
 378 EXPORT_SYMBOL_GPL(ir_rc5_timer_keyup);
 379
 380 /*
 381  * Local variables:
 382  * c-basic-offset: 8
 383  * End:
 384  */