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