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