arch/arm/mach-bcmring/csp/tmr/tmrHw.c

   1 /*****************************************************************************
   2 * Copyright 2003 - 2008 Broadcom Corporation.  All rights reserved.
   3 *
   4 * Unless you and Broadcom execute a separate written software license
   5 * agreement governing use of this software, this software is licensed to you
   6 * under the terms of the GNU General Public License version 2, available at
   7 * http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
   8 *
   9 * Notwithstanding the above, under no circumstances may you combine this
  10 * software in any way with any other Broadcom software provided under a
  11 * license other than the GPL, without Broadcom's express prior written
  12 * consent.
  13 *****************************************************************************/
  14
  15 /****************************************************************************/
  16 /**
  17 *  @file    tmrHw.c
  18 *
  19 *  @brief   Low level Timer driver routines
  20 *
  21 *  @note
  22 *
  23 *   These routines provide basic timer functionality only.
  24 */
  25 /****************************************************************************/
  26
  27 /* ---- Include Files ---------------------------------------------------- */
  28
  29 #include <csp/errno.h>
  30 #include <csp/stdint.h>
  31
  32 #include <csp/tmrHw.h>
  33 #include <mach/csp/tmrHw_reg.h>
  34
  35 #define tmrHw_ASSERT(a)                     if (!(a)) *(char *)0 = 0
  36 #define tmrHw_MILLISEC_PER_SEC              (1000)
  37
  38 #define tmrHw_LOW_1_RESOLUTION_COUNT        (tmrHw_LOW_RESOLUTION_CLOCK / tmrHw_MILLISEC_PER_SEC)
  39 #define tmrHw_LOW_1_MAX_MILLISEC            (0xFFFFFFFF / tmrHw_LOW_1_RESOLUTION_COUNT)
  40 #define tmrHw_LOW_16_RESOLUTION_COUNT       (tmrHw_LOW_1_RESOLUTION_COUNT / 16)
  41 #define tmrHw_LOW_16_MAX_MILLISEC           (0xFFFFFFFF / tmrHw_LOW_16_RESOLUTION_COUNT)
  42 #define tmrHw_LOW_256_RESOLUTION_COUNT      (tmrHw_LOW_1_RESOLUTION_COUNT / 256)
  43 #define tmrHw_LOW_256_MAX_MILLISEC          (0xFFFFFFFF / tmrHw_LOW_256_RESOLUTION_COUNT)
  44
  45 #define tmrHw_HIGH_1_RESOLUTION_COUNT       (tmrHw_HIGH_RESOLUTION_CLOCK / tmrHw_MILLISEC_PER_SEC)
  46 #define tmrHw_HIGH_1_MAX_MILLISEC           (0xFFFFFFFF / tmrHw_HIGH_1_RESOLUTION_COUNT)
  47 #define tmrHw_HIGH_16_RESOLUTION_COUNT      (tmrHw_HIGH_1_RESOLUTION_COUNT / 16)
  48 #define tmrHw_HIGH_16_MAX_MILLISEC          (0xFFFFFFFF / tmrHw_HIGH_16_RESOLUTION_COUNT)
  49 #define tmrHw_HIGH_256_RESOLUTION_COUNT     (tmrHw_HIGH_1_RESOLUTION_COUNT / 256)
  50 #define tmrHw_HIGH_256_MAX_MILLISEC         (0xFFFFFFFF / tmrHw_HIGH_256_RESOLUTION_COUNT)
  51
  52 static void ResetTimer(tmrHw_ID_t timerId)
  53     __attribute__ ((section(".aramtext")));
  54 static int tmrHw_divide(int num, int denom)
  55     __attribute__ ((section(".aramtext")));
  56
  57 /****************************************************************************/
  58 /**
  59 *  @brief   Get timer capability
  60 *
  61 *  This function returns various capabilities/attributes of a timer
  62 *
  63 *  @return  Capability
  64 *
  65 */
  66 /****************************************************************************/
  67 uint32_t tmrHw_getTimerCapability(tmrHw_ID_t timerId,   /*  [ IN ] Timer Id */
  68                                   tmrHw_CAPABILITY_e capability /*  [ IN ] Timer capability */
  69 ) {
  70         switch (capability) {
  71         case tmrHw_CAPABILITY_CLOCK:
  72                 return (timerId <=
  73                         1) ? tmrHw_LOW_RESOLUTION_CLOCK :
  74                     tmrHw_HIGH_RESOLUTION_CLOCK;
  75         case tmrHw_CAPABILITY_RESOLUTION:
  76                 return 32;
  77         default:
  78                 return 0;
  79         }
  80         return 0;
  81 }
  82
  83 /****************************************************************************/
  84 /**
  85 *  @brief   Resets a timer
  86 *
  87 *  This function initializes  timer
  88 *
  89 *  @return  void
  90 *
  91 */
  92 /****************************************************************************/
  93 static void ResetTimer(tmrHw_ID_t timerId       /*  [ IN ] Timer Id */
  94 ) {
  95         /* Reset timer */
  96         pTmrHw[timerId].LoadValue = 0;
  97         pTmrHw[timerId].CurrentValue = 0xFFFFFFFF;
  98         pTmrHw[timerId].Control = 0;
  99         pTmrHw[timerId].BackgroundLoad = 0;
 100         /* Always configure as a 32 bit timer */
 101         pTmrHw[timerId].Control |= tmrHw_CONTROL_32BIT;
 102         /* Clear interrupt only if raw status interrupt is set */
 103         if (pTmrHw[timerId].RawInterruptStatus) {
 104                 pTmrHw[timerId].InterruptClear = 0xFFFFFFFF;
 105         }
 106 }
 107
 108 /****************************************************************************/
 109 /**
 110 *  @brief   Sets counter value for an interval in ms
 111 *
 112 *  @return   On success: Effective counter value set
 113 *            On failure: 0
 114 *
 115 */
 116 /****************************************************************************/
 117 static tmrHw_INTERVAL_t SetTimerPeriod(tmrHw_ID_t timerId,      /*  [ IN ] Timer Id */
 118                                        tmrHw_INTERVAL_t msec    /*  [ IN ] Interval in milli-second */
 119 ) {
 120         uint32_t scale = 0;
 121         uint32_t count = 0;
 122
 123         if (timerId == 0 || timerId == 1) {
 124                 if (msec <= tmrHw_LOW_1_MAX_MILLISEC) {
 125                         pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_1;
 126                         scale = tmrHw_LOW_1_RESOLUTION_COUNT;
 127                 } else if (msec <= tmrHw_LOW_16_MAX_MILLISEC) {
 128                         pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_16;
 129                         scale = tmrHw_LOW_16_RESOLUTION_COUNT;
 130                 } else if (msec <= tmrHw_LOW_256_MAX_MILLISEC) {
 131                         pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_256;
 132                         scale = tmrHw_LOW_256_RESOLUTION_COUNT;
 133                 } else {
 134                         return 0;
 135                 }
 136
 137                 count = msec * scale;
 138                 /* Set counter value */
 139                 pTmrHw[timerId].LoadValue = count;
 140                 pTmrHw[timerId].BackgroundLoad = count;
 141
 142         } else if (timerId == 2 || timerId == 3) {
 143                 if (msec <= tmrHw_HIGH_1_MAX_MILLISEC) {
 144                         pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_1;
 145                         scale = tmrHw_HIGH_1_RESOLUTION_COUNT;
 146                 } else if (msec <= tmrHw_HIGH_16_MAX_MILLISEC) {
 147                         pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_16;
 148                         scale = tmrHw_HIGH_16_RESOLUTION_COUNT;
 149                 } else if (msec <= tmrHw_HIGH_256_MAX_MILLISEC) {
 150                         pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_256;
 151                         scale = tmrHw_HIGH_256_RESOLUTION_COUNT;
 152                 } else {
 153                         return 0;
 154                 }
 155
 156                 count = msec * scale;
 157                 /* Set counter value */
 158                 pTmrHw[timerId].LoadValue = count;
 159                 pTmrHw[timerId].BackgroundLoad = count;
 160         }
 161         return count / scale;
 162 }
 163
 164 /****************************************************************************/
 165 /**
 166 *  @brief   Configures a periodic timer in terms of timer interrupt rate
 167 *
 168 *  This function initializes a periodic timer to generate specific number of
 169 *  timer interrupt per second
 170 *
 171 *  @return   On success: Effective timer frequency
 172 *            On failure: 0
 173 *
 174 */
 175 /****************************************************************************/
 176 tmrHw_RATE_t tmrHw_setPeriodicTimerRate(tmrHw_ID_t timerId,     /*  [ IN ] Timer Id */
 177                                         tmrHw_RATE_t rate       /*  [ IN ] Number of timer interrupt per second */
 178 ) {
 179         uint32_t resolution = 0;
 180         uint32_t count = 0;
 181         ResetTimer(timerId);
 182
 183         /* Set timer mode periodic */
 184         pTmrHw[timerId].Control |= tmrHw_CONTROL_PERIODIC;
 185         pTmrHw[timerId].Control &= ~tmrHw_CONTROL_ONESHOT;
 186         /* Set timer in highest resolution */
 187         pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_1;
 188
 189         if (rate && (timerId == 0 || timerId == 1)) {
 190                 if (rate > tmrHw_LOW_RESOLUTION_CLOCK) {
 191                         return 0;
 192                 }
 193                 resolution = tmrHw_LOW_RESOLUTION_CLOCK;
 194         } else if (rate && (timerId == 2 || timerId == 3)) {
 195                 if (rate > tmrHw_HIGH_RESOLUTION_CLOCK) {
 196                         return 0;
 197                 } else {
 198                         resolution = tmrHw_HIGH_RESOLUTION_CLOCK;
 199                 }
 200         } else {
 201                 return 0;
 202         }
 203         /* Find the counter value */
 204         count = resolution / rate;
 205         /* Set counter value */
 206         pTmrHw[timerId].LoadValue = count;
 207         pTmrHw[timerId].BackgroundLoad = count;
 208
 209         return resolution / count;
 210 }
 211
 212 /****************************************************************************/
 213 /**
 214 *  @brief   Configures a periodic timer to generate timer interrupt after
 215 *           certain time interval
 216 *
 217 *  This function initializes a periodic timer to generate timer interrupt
 218 *  after every time interval in millisecond
 219 *
 220 *  @return   On success: Effective interval set in milli-second
 221 *            On failure: 0
 222 *
 223 */
 224 /****************************************************************************/
 225 tmrHw_INTERVAL_t tmrHw_setPeriodicTimerInterval(tmrHw_ID_t timerId,     /*  [ IN ] Timer Id */
 226                                                 tmrHw_INTERVAL_t msec   /*  [ IN ] Interval in milli-second */
 227 ) {
 228         ResetTimer(timerId);
 229
 230         /* Set timer mode periodic */
 231         pTmrHw[timerId].Control |= tmrHw_CONTROL_PERIODIC;
 232         pTmrHw[timerId].Control &= ~tmrHw_CONTROL_ONESHOT;
 233
 234         return SetTimerPeriod(timerId, msec);
 235 }
 236
 237 /****************************************************************************/
 238 /**
 239 *  @brief   Configures a periodic timer to generate timer interrupt just once
 240 *           after certain time interval
 241 *
 242 *  This function initializes a periodic timer to generate a single ticks after
 243 *  certain time interval in millisecond
 244 *
 245 *  @return   On success: Effective interval set in milli-second
 246 *            On failure: 0
 247 *
 248 */
 249 /****************************************************************************/
 250 tmrHw_INTERVAL_t tmrHw_setOneshotTimerInterval(tmrHw_ID_t timerId,      /*  [ IN ] Timer Id */
 251                                                tmrHw_INTERVAL_t msec    /*  [ IN ] Interval in milli-second */
 252 ) {
 253         ResetTimer(timerId);
 254
 255         /* Set timer mode oneshot */
 256         pTmrHw[timerId].Control |= tmrHw_CONTROL_PERIODIC;
 257         pTmrHw[timerId].Control |= tmrHw_CONTROL_ONESHOT;
 258
 259         return SetTimerPeriod(timerId, msec);
 260 }
 261
 262 /****************************************************************************/
 263 /**
 264 *  @brief   Configures a timer to run as a free running timer
 265 *
 266 *  This function initializes a timer to run as a free running timer
 267 *
 268 *  @return   Timer resolution (count / sec)
 269 *
 270 */
 271 /****************************************************************************/
 272 tmrHw_RATE_t tmrHw_setFreeRunningTimer(tmrHw_ID_t timerId,      /*  [ IN ] Timer Id */
 273                                        uint32_t divider /*  [ IN ] Dividing the clock frequency */
 274 ) {
 275         uint32_t scale = 0;
 276
 277         ResetTimer(timerId);
 278         /* Set timer as free running mode */
 279         pTmrHw[timerId].Control &= ~tmrHw_CONTROL_PERIODIC;
 280         pTmrHw[timerId].Control &= ~tmrHw_CONTROL_ONESHOT;
 281
 282         if (divider >= 64) {
 283                 pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_256;
 284                 scale = 256;
 285         } else if (divider >= 8) {
 286                 pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_16;
 287                 scale = 16;
 288         } else {
 289                 pTmrHw[timerId].Control |= tmrHw_CONTROL_PRESCALE_1;
 290                 scale = 1;
 291         }
 292
 293         if (timerId == 0 || timerId == 1) {
 294                 return tmrHw_divide(tmrHw_LOW_RESOLUTION_CLOCK, scale);
 295         } else if (timerId == 2 || timerId == 3) {
 296                 return tmrHw_divide(tmrHw_HIGH_RESOLUTION_CLOCK, scale);
 297         }
 298
 299         return 0;
 300 }
 301
 302 /****************************************************************************/
 303 /**
 304 *  @brief   Starts a timer
 305 *
 306 *  This function starts a preconfigured timer
 307 *
 308 *  @return  -1     - On Failure
 309 *            0     - On Success
 310 *
 311 */
 312 /****************************************************************************/
 313 int tmrHw_startTimer(tmrHw_ID_t timerId /*  [ IN ] Timer id */
 314 ) {
 315         pTmrHw[timerId].Control |= tmrHw_CONTROL_TIMER_ENABLE;
 316         return 0;
 317 }
 318
 319 /****************************************************************************/
 320 /**
 321 *  @brief   Stops a timer
 322 *
 323 *  This function stops a running timer
 324 *
 325 *  @return  -1     - On Failure
 326 *            0     - On Success
 327 *
 328 */
 329 /****************************************************************************/
 330 int tmrHw_stopTimer(tmrHw_ID_t timerId  /*  [ IN ] Timer id */
 331 ) {
 332         pTmrHw[timerId].Control &= ~tmrHw_CONTROL_TIMER_ENABLE;
 333         return 0;
 334 }
 335
 336 /****************************************************************************/
 337 /**
 338 *  @brief   Gets current timer count
 339 *
 340 *  This function returns the current timer value
 341 *
 342 *  @return  Current downcounting timer value
 343 *
 344 */
 345 /****************************************************************************/
 346 uint32_t tmrHw_GetCurrentCount(tmrHw_ID_t timerId       /*  [ IN ] Timer id */
 347 ) {
 348         /* return 32 bit timer value */
 349         switch (pTmrHw[timerId].Control & tmrHw_CONTROL_MODE_MASK) {
 350         case tmrHw_CONTROL_FREE_RUNNING:
 351                 if (pTmrHw[timerId].CurrentValue) {
 352                         return tmrHw_MAX_COUNT - pTmrHw[timerId].CurrentValue;
 353                 }
 354                 break;
 355         case tmrHw_CONTROL_PERIODIC:
 356         case tmrHw_CONTROL_ONESHOT:
 357                 return pTmrHw[timerId].BackgroundLoad -
 358                     pTmrHw[timerId].CurrentValue;
 359         }
 360         return 0;
 361 }
 362
 363 /****************************************************************************/
 364 /**
 365 *  @brief   Gets timer count rate
 366 *
 367 *  This function returns the number of counts per second
 368 *
 369 *  @return  Count rate
 370 *
 371 */
 372 /****************************************************************************/
 373 tmrHw_RATE_t tmrHw_getCountRate(tmrHw_ID_t timerId      /*  [ IN ] Timer id */
 374 ) {
 375         uint32_t divider = 0;
 376
 377         switch (pTmrHw[timerId].Control & tmrHw_CONTROL_PRESCALE_MASK) {
 378         case tmrHw_CONTROL_PRESCALE_1:
 379                 divider = 1;
 380                 break;
 381         case tmrHw_CONTROL_PRESCALE_16:
 382                 divider = 16;
 383                 break;
 384         case tmrHw_CONTROL_PRESCALE_256:
 385                 divider = 256;
 386                 break;
 387         default:
 388                 tmrHw_ASSERT(0);
 389         }
 390
 391         if (timerId == 0 || timerId == 1) {
 392                 return tmrHw_divide(tmrHw_LOW_RESOLUTION_CLOCK, divider);
 393         } else {
 394                 return tmrHw_divide(tmrHw_HIGH_RESOLUTION_CLOCK, divider);
 395         }
 396         return 0;
 397 }
 398
 399 /****************************************************************************/
 400 /**
 401 *  @brief   Enables timer interrupt
 402 *
 403 *  This function enables the timer interrupt
 404 *
 405 *  @return   N/A
 406 *
 407 */
 408 /****************************************************************************/
 409 void tmrHw_enableInterrupt(tmrHw_ID_t timerId   /*  [ IN ] Timer id */
 410 ) {
 411         pTmrHw[timerId].Control |= tmrHw_CONTROL_INTERRUPT_ENABLE;
 412 }
 413
 414 /****************************************************************************/
 415 /**
 416 *  @brief   Disables timer interrupt
 417 *
 418 *  This function disable the timer interrupt
 419 *
 420 *  @return   N/A
 421 *
 422 */
 423 /****************************************************************************/
 424 void tmrHw_disableInterrupt(tmrHw_ID_t timerId  /*  [ IN ] Timer id */
 425 ) {
 426         pTmrHw[timerId].Control &= ~tmrHw_CONTROL_INTERRUPT_ENABLE;
 427 }
 428
 429 /****************************************************************************/
 430 /**
 431 *  @brief   Clears the interrupt
 432 *
 433 *  This function clears the timer interrupt
 434 *
 435 *  @return   N/A
 436 *
 437 *  @note
 438 *     Must be called under the context of ISR
 439 */
 440 /****************************************************************************/
 441 void tmrHw_clearInterrupt(tmrHw_ID_t timerId    /*  [ IN ] Timer id */
 442 ) {
 443         pTmrHw[timerId].InterruptClear = 0x1;
 444 }
 445
 446 /****************************************************************************/
 447 /**
 448 *  @brief   Gets the interrupt status
 449 *
 450 *  This function returns timer interrupt status
 451 *
 452 *  @return   Interrupt status
 453 */
 454 /****************************************************************************/
 455 tmrHw_INTERRUPT_STATUS_e tmrHw_getInterruptStatus(tmrHw_ID_t timerId    /*  [ IN ] Timer id */
 456 ) {
 457         if (pTmrHw[timerId].InterruptStatus) {
 458                 return tmrHw_INTERRUPT_STATUS_SET;
 459         } else {
 460                 return tmrHw_INTERRUPT_STATUS_UNSET;
 461         }
 462 }
 463
 464 /****************************************************************************/
 465 /**
 466 *  @brief   Indentifies a timer causing interrupt
 467 *
 468 *  This functions returns a timer causing interrupt
 469 *
 470 *  @return  0xFFFFFFFF   : No timer causing an interrupt
 471 *           ! 0xFFFFFFFF : timer causing an interrupt
 472 *  @note
 473 *     tmrHw_clearIntrrupt() must be called with a valid timer id after calling this function
 474 */
 475 /****************************************************************************/
 476 tmrHw_ID_t tmrHw_getInterruptSource(void        /*  void */
 477 ) {
 478         int i;
 479
 480         for (i = 0; i < tmrHw_TIMER_NUM_COUNT; i++) {
 481                 if (pTmrHw[i].InterruptStatus) {
 482                         return i;
 483                 }
 484         }
 485
 486         return 0xFFFFFFFF;
 487 }
 488
 489 /****************************************************************************/
 490 /**
 491 *  @brief   Displays specific timer registers
 492 *
 493 *
 494 *  @return  void
 495 *
 496 */
 497 /****************************************************************************/
 498 void tmrHw_printDebugInfo(tmrHw_ID_t timerId,   /*  [ IN ] Timer id */
 499                           int (*fpPrint) (const char *, ...)    /*  [ IN ] Print callback function */
 500 ) {
 501         (*fpPrint) ("Displaying register contents \n\n");
 502         (*fpPrint) ("Timer %d: Load value              0x%X\n", timerId,
 503                     pTmrHw[timerId].LoadValue);
 504         (*fpPrint) ("Timer %d: Background load value   0x%X\n", timerId,
 505                     pTmrHw[timerId].BackgroundLoad);
 506         (*fpPrint) ("Timer %d: Control                 0x%X\n", timerId,
 507                     pTmrHw[timerId].Control);
 508         (*fpPrint) ("Timer %d: Interrupt clear         0x%X\n", timerId,
 509                     pTmrHw[timerId].InterruptClear);
 510         (*fpPrint) ("Timer %d: Interrupt raw interrupt 0x%X\n", timerId,
 511                     pTmrHw[timerId].RawInterruptStatus);
 512         (*fpPrint) ("Timer %d: Interrupt status        0x%X\n", timerId,
 513                     pTmrHw[timerId].InterruptStatus);
 514 }
 515
 516 /****************************************************************************/
 517 /**
 518 *  @brief   Use a timer to perform a busy wait delay for a number of usecs.
 519 *
 520 *  @return   N/A
 521 */
 522 /****************************************************************************/
 523 void tmrHw_udelay(tmrHw_ID_t timerId,   /*  [ IN ] Timer id */
 524                   unsigned long usecs /*  [ IN ] usec to delay */
 525 ) {
 526         tmrHw_RATE_t usec_tick_rate;
 527         tmrHw_COUNT_t start_time;
 528         tmrHw_COUNT_t delta_time;
 529
 530         start_time = tmrHw_GetCurrentCount(timerId);
 531         usec_tick_rate = tmrHw_divide(tmrHw_getCountRate(timerId), 1000000);
 532         delta_time = usecs * usec_tick_rate;
 533
 534         /* Busy wait */
 535         while (delta_time > (tmrHw_GetCurrentCount(timerId) - start_time))
 536                 ;
 537 }
 538
 539 /****************************************************************************/
 540 /**
 541 *  @brief   Local Divide function
 542 *
 543 *  This function does the divide
 544 *
 545 *  @return divide value
 546 *
 547 */
 548 /****************************************************************************/
 549 static int tmrHw_divide(int num, int denom)
 550 {
 551         int r;
 552         int t = 1;
 553
 554         /* Shift denom and t up to the largest value to optimize algorithm */
 555         /* t contains the units of each divide */
 556         while ((denom & 0x40000000) == 0) {     /* fails if denom=0 */
 557                 denom = denom << 1;
 558                 t = t << 1;
 559         }
 560
 561         /* Intialize the result */
 562         r = 0;
 563
 564         do {
 565                 /* Determine if there exists a positive remainder */
 566                 if ((num - denom) >= 0) {
 567                         /* Accumlate t to the result and calculate a new remainder */
 568                         num = num - denom;
 569                         r = r + t;
 570                 }
 571                 /* Continue to shift denom and shift t down to 0 */
 572                 denom = denom >> 1;
 573                 t = t >> 1;
 574         } while (t != 0);
 575         return r;
 576 }