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         ir->keytable.size = ir_roundup_tablesize(ir_codes->size);
  60         ir->keytable.scan = kzalloc(ir->keytable.size *
  61                                     sizeof(struct ir_scancode), GFP_KERNEL);
  62         if (!ir->keytable.scan)
  63                 return -ENOMEM;
  64
  65         IR_dprintk(1, "Allocated space for %d keycode entries (%zd bytes)\n",
  66                 ir->keytable.size,
  67                 ir->keytable.size * sizeof(ir->keytable.scan));
  68
  69         ir_copy_table(&ir->keytable, ir_codes);
  70         ir_set_keycode_table(dev, &ir->keytable);
  71
  72         clear_bit(0, dev->keybit);
  73         set_bit(EV_KEY, dev->evbit);
  74         if (repeat)
  75                 set_bit(EV_REP, dev->evbit);
  76
  77         return 0;
  78 }
  79 EXPORT_SYMBOL_GPL(ir_input_init);
  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 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)
  93 {
  94         u32 keycode = ir_g_keycode_from_table(dev, 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->keycode = keycode;
 103                 ir->keypressed = 1;
 104                 ir_input_key_event(dev,ir);
 105         }
 106 }
 107 EXPORT_SYMBOL_GPL(ir_input_keydown);
 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 EXPORT_SYMBOL_GPL(ir_extract_bits);
 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 EXPORT_SYMBOL_GPL(ir_dump_samples);
 152
 153 /* decode raw samples, pulse distance coding used by NEC remotes */
 154 int ir_decode_pulsedistance(u32 *samples, int count, int low, int high)
 155 {
 156         int i,last,bit,len;
 157         u32 curBit;
 158         u32 value;
 159
 160         /* find start burst */
 161         for (i = len = 0; i < count * 32; i++) {
 162                 bit = getbit(samples,i);
 163                 if (bit) {
 164                         len++;
 165                 } else {
 166                         if (len >= 29)
 167                                 break;
 168                         len = 0;
 169                 }
 170         }
 171
 172         /* start burst to short */
 173         if (len < 29)
 174                 return 0xffffffff;
 175
 176         /* find start silence */
 177         for (len = 0; i < count * 32; i++) {
 178                 bit = getbit(samples,i);
 179                 if (bit) {
 180                         break;
 181                 } else {
 182                         len++;
 183                 }
 184         }
 185
 186         /* silence to short */
 187         if (len < 7)
 188                 return 0xffffffff;
 189
 190         /* go decoding */
 191         len   = 0;
 192         last = 1;
 193         value = 0; curBit = 1;
 194         for (; i < count * 32; i++) {
 195                 bit  = getbit(samples,i);
 196                 if (last) {
 197                         if(bit) {
 198                                 continue;
 199                         } else {
 200                                 len = 1;
 201                         }
 202                 } else {
 203                         if (bit) {
 204                                 if (len > (low + high) /2)
 205                                         value |= curBit;
 206                                 curBit <<= 1;
 207                                 if (curBit == 1)
 208                                         break;
 209                         } else {
 210                                 len++;
 211                         }
 212                 }
 213                 last = bit;
 214         }
 215
 216         return value;
 217 }
 218 EXPORT_SYMBOL_GPL(ir_decode_pulsedistance);
 219
 220 /* decode raw samples, biphase coding, used by rc5 for example */
 221 int ir_decode_biphase(u32 *samples, int count, int low, int high)
 222 {
 223         int i,last,bit,len,flips;
 224         u32 value;
 225
 226         /* find start bit (1) */
 227         for (i = 0; i < 32; i++) {
 228                 bit = getbit(samples,i);
 229                 if (bit)
 230                         break;
 231         }
 232
 233         /* go decoding */
 234         len   = 0;
 235         flips = 0;
 236         value = 1;
 237         for (; i < count * 32; i++) {
 238                 if (len > high)
 239                         break;
 240                 if (flips > 1)
 241                         break;
 242                 last = bit;
 243                 bit  = getbit(samples,i);
 244                 if (last == bit) {
 245                         len++;
 246                         continue;
 247                 }
 248                 if (len < low) {
 249                         len++;
 250                         flips++;
 251                         continue;
 252                 }
 253                 value <<= 1;
 254                 value |= bit;
 255                 flips = 0;
 256                 len   = 1;
 257         }
 258         return value;
 259 }
 260 EXPORT_SYMBOL_GPL(ir_decode_biphase);
 261
 262 /* RC5 decoding stuff, moved from bttv-input.c to share it with
 263  * saa7134 */
 264
 265 /* decode raw bit pattern to RC5 code */
 266 u32 ir_rc5_decode(unsigned int code)
 267 {
 268         unsigned int org_code = code;
 269         unsigned int pair;
 270         unsigned int rc5 = 0;
 271         int i;
 272
 273         for (i = 0; i < 14; ++i) {
 274                 pair = code & 0x3;
 275                 code >>= 2;
 276
 277                 rc5 <<= 1;
 278                 switch (pair) {
 279                 case 0:
 280                 case 2:
 281                         break;
 282                 case 1:
 283                         rc5 |= 1;
 284                         break;
 285                 case 3:
 286                         IR_dprintk(1, "ir-common: ir_rc5_decode(%x) bad code\n", org_code);
 287                         return 0;
 288                 }
 289         }
 290         IR_dprintk(1, "ir-common: code=%x, rc5=%x, start=%x, toggle=%x, address=%x, "
 291                 "instr=%x\n", rc5, org_code, RC5_START(rc5),
 292                 RC5_TOGGLE(rc5), RC5_ADDR(rc5), RC5_INSTR(rc5));
 293         return rc5;
 294 }
 295 EXPORT_SYMBOL_GPL(ir_rc5_decode);
 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                 IR_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                 IR_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                         IR_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                                 IR_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                         }
 350
 351                         /* Set/reset key-up timer */
 352                         timeout = current_jiffies +
 353                                   msecs_to_jiffies(ir->rc5_key_timeout);
 354                         mod_timer(&ir->timer_keyup, timeout);
 355
 356                         /* Save code for repeat test */
 357                         ir->last_rc5 = rc5;
 358                 }
 359         }
 360 }
 361 EXPORT_SYMBOL_GPL(ir_rc5_timer_end);
 362
 363 void ir_rc5_timer_keyup(unsigned long data)
 364 {
 365         struct card_ir *ir = (struct card_ir *)data;
 366
 367         IR_dprintk(1, "ir-common: key released\n");
 368         ir_input_nokey(ir->dev, &ir->ir);
 369 }
 370 EXPORT_SYMBOL_GPL(ir_rc5_timer_keyup);