Pileus Git - ~andy/csm213a-hw/blob - hw2/main.cpp

   1 #include "messages.h"
   2
   3 #include "mbed.h"
   4 #include "serial_irq.h"
   5 #include "serial_dma.h"
   6 #include "timer_dma.h"
   7
   8 /**
   9  * Mode of operation:
  10  *   Devices 1 and 2 synchronize clocks using serial messages.
  11  *
  12  *   1. Each serial message timestamped using the hardware timer capture
  13  *      registers in both the sender and receiver.
  14  *   2. The sender transmits the send timestamp during the next time-sync
  15  *      message.
  16  *   3. The receiver then compares the senders timestamp with it's own
  17  *      timestamp for the corresponding messages and calculates an offset.
  18  *   4. The offset is used to compensate the receivers local clock.
  19  *
  20  *   Time synchronization is performed in both directions.
  21  */
  22
  23 /*******************
  24  * Timer functions *
  25  *******************/
  26
  27 #define NSEC_PER_SEC 1000000000ULL
  28
  29 uint64_t time_last_local; // timestamp at last time sync
  30 uint64_t time_last_world; // offset at last time sync
  31
  32 /**
  33  * Generate time stamp for an async event:
  34  *   local: drift compensated wall-clock time
  35  *   world: nanoseconds in world time world
  36  *   valid: local timestamp at valid valid
  37  */
  38 //uint64_t time_to_local(uint64_t world, uint64_t valid)
  39 //{
  40 //      uint64_t now =
  41 //      local =  + (stamp);
  42 //}
  43
  44 /**
  45  * Generate time stamp for an async event:
  46  *   time:  drift compensated wall-clock time
  47  *   stamp: event timestamp from PIT Module
  48  */
  49 uint64_t time_to_world(uint64_t local)
  50 {
  51         uint64_t elapsed = local - time_last_local;
  52         return time_last_world + elapsed;
  53 }
  54
  55 /**
  56  * Compensate the Real-Time-Clock oscillator for
  57  * temperature and drift errors. Called at 1Hz and
  58  * synchronous to the RTC 1Hz output.
  59  */
  60 void time_rtc_comp(void)
  61 {
  62         // todo
  63 }
  64
  65 /**
  66  * Synchronize the timer internal state with updates
  67  * from an external time sync message.
  68  *   local: our internal timestamp for the event
  69  *   world: reference timestamp from the other device
  70  */
  71 void time_ext_init(uint64_t local, uint64_t world)
  72 {
  73         sirq_printf("initialize clocks: %d -> %d\r\n",
  74                         (int)(local/NSEC_PER_SEC),
  75                         (int)(world/NSEC_PER_SEC));
  76
  77         time_last_local = local;
  78         time_last_world = world;
  79 }
  80
  81 /**
  82  * Synchronize the timer internal state with updates
  83  * from an external time sync message.
  84  *   local: our internal timestamp for the event
  85  *   world: reference timestamp from the other device
  86  */
  87 void time_ext_sync(uint64_t local, uint64_t world)
  88 {
  89         sirq_printf("syncing clocks: %d -> %d\r\n",
  90                         (int)(local/NSEC_PER_SEC),
  91                         (int)(world/NSEC_PER_SEC));
  92
  93         time_last_local = local;
  94         time_last_world = world;
  95 }
  96
  97 /************************
  98  * Serial I/O functions *
  99  ************************/
 100
 101 typedef struct {
 102         int      index;
 103         int      state;
 104         uint8_t  buffer[256];
 105 } parser_t;
 106
 107 const  uint64_t serial_sync_delay = NSEC_PER_SEC * 2; // 1hz
 108 static uint64_t serial_sync_due   = 0;
 109
 110 static tdma_t  *serial_tdma_rcv   = NULL;
 111 static tdma_t  *serial_tdma_xmt   = NULL;
 112
 113 static uint64_t serial_prev_local = 0;
 114 static uint64_t serial_prev_seq   = 0;
 115
 116 static uint64_t serial_xmt_local  = 0;
 117 static uint64_t serial_xmt_seq    = 0;
 118
 119 /**
 120  * Output time sync message
 121  */
 122 void serial_send_sync(sirq_t *port, uint64_t now)
 123 {
 124         if (serial_sync_due == 0 || now < serial_sync_due)
 125                 return; // not ready
 126
 127         // Calculate world time
 128         uint64_t world = time_to_world(serial_xmt_local);
 129
 130         // Message data
 131         header_t   head;
 132         sync_msg_t body;
 133
 134         // Transmit sync message
 135         head.header = MSG_HEADER;
 136         head.msgid  = MSG_ID_SYNC;
 137         head.length = sizeof(body);
 138         head.cksum  = 0; // todo
 139
 140         body.seq          = serial_xmt_seq;
 141         body.time.seconds = world / NSEC_PER_SEC;
 142         body.time.nanosec = world % NSEC_PER_SEC;
 143
 144         sirq_write(port, &head, sizeof(head));
 145         sirq_write(port, &body, sizeof(body));
 146
 147         serial_xmt_seq  += 1;
 148         serial_sync_due  = 0;
 149
 150         // Debug
 151         sirq_printf("sync msg transmit\r\n");
 152
 153         // save transmit time
 154         for (int i = 0; i < 1000; i++)
 155                 asm("nop");
 156         int valid = tdma_stamp(serial_tdma_xmt, &serial_xmt_local);
 157         if (!valid)
 158                 sirq_printf("missing sync transmit time\r\n");
 159         tdma_reset(serial_tdma_xmt);
 160 }
 161
 162 /**
 163  * Output external event received message
 164  *   event: id of the received event
 165  *   time:  compensated timestamp of the event
 166  */
 167 void serial_send_event(uint16_t event, uint64_t local)
 168 {
 169         uint64_t world = time_to_world(local);
 170
 171         ntime_t time = {};
 172         time.seconds = (uint32_t)(world / NSEC_PER_SEC);
 173         time.nanosec = (uint32_t)(world % NSEC_PER_SEC);
 174
 175         sirq_printf("event received - %08x:%08x - %u.%u\r\n",
 176                 (uint32_t)(local >> 32), (uint32_t)local,
 177                 time.seconds, time.nanosec);
 178         // todo
 179 }
 180
 181 /**
 182  * Handle sync message
 183  */
 184 void serial_handle_sync(sync_msg_t *msg)
 185 {
 186         // Read receive timestamp for next time sync message
 187         uint64_t current = 0;
 188         int valid = tdma_stamp(serial_tdma_rcv, &current);
 189         if (!valid)
 190                 sirq_printf("missing sync receive time\r\n");
 191         tdma_reset(serial_tdma_rcv);
 192
 193         // Lookup times
 194         uint64_t world = ((uint64_t)msg->time.seconds) * NSEC_PER_SEC
 195                        + ((uint64_t)msg->time.nanosec);
 196
 197         // Initialize
 198         if (msg->seq == 0) {
 199                 uint64_t local = tdma_time();
 200                 time_ext_init(local, world);
 201         }
 202
 203         // Valid times timestamp
 204         if (serial_prev_seq == (msg->seq-1)) {
 205                 uint64_t local = serial_prev_local;
 206                 time_ext_sync(local, world);
 207         }
 208
 209         // Queue transmit to other board
 210         serial_sync_due   = tdma_time() + serial_sync_delay;
 211
 212         // Update states
 213         serial_prev_local = current;
 214         serial_prev_seq   = msg->seq;
 215 }
 216
 217 /**
 218  * Handle event message
 219  */
 220 void serial_handle_event(event_msg_t *msg)
 221 {
 222 }
 223
 224 /**
 225  * Deliver message
 226  */
 227 void serial_deliver(int msgid, void *body)
 228 {
 229         switch (msgid) {
 230                 case MSG_ID_SYNC:
 231                         sirq_printf("received sync msg\r\n");
 232                         serial_handle_sync((sync_msg_t*)body);
 233                         break;
 234                 case MSG_ID_EVENT:
 235                         sirq_printf("received event msg\r\n");
 236                         serial_handle_event((event_msg_t*)body);
 237                         break;
 238         }
 239 }
 240
 241 /**
 242  * Process serial receive messages
 243  */
 244 void serial_receive(parser_t *parser, int byte)
 245 {
 246         //sirq_printf("serial_receive - %02x\r\n", byte);
 247
 248         // Lookup pointers
 249         header_t *head = (header_t*)parser->buffer;
 250         void     *body = (void*)(head+1);
 251         const int max_length = sizeof(parser->buffer)-sizeof(header_t);
 252
 253         // Process uart messages
 254         parser->buffer[parser->index++] = byte;
 255         switch (parser->state) {
 256                 case 0: // Search
 257                         if (parser->index == sizeof(uint16_t)) {
 258                                 if (head->header == MSG_HEADER) {
 259                                         parser->state = 1;
 260                                 } else {
 261                                         parser->buffer[0] = parser->buffer[1];
 262                                         parser->index = 1;
 263                                 }
 264                         }
 265                         break;
 266                 case 1: // Header
 267                         if (parser->index == sizeof(header_t)) {
 268                                 if (head->length <= max_length &&
 269                                     head->msgid  <= MSG_MAXID) {
 270                                         parser->state = 2;
 271                                 } else {
 272                                         parser->index = 0;
 273                                         parser->state = 0;
 274                                 }
 275                         }
 276                         break;
 277                 case 2: // Data
 278                         if (parser->index == (int)sizeof(header_t)+head->length) {
 279                                 serial_deliver(head->msgid, body);
 280                                 parser->index = 0;
 281                                 parser->state = 0;
 282                         }
 283                         break;
 284         }
 285 }
 286
 287 /********************
 288  * Data definitions *
 289  ********************/
 290
 291 // LEDs
 292 DigitalOut led1(LED1);
 293 DigitalOut led2(LED2);
 294
 295 // Message Parsers
 296 parser_t   parser_dbg;
 297 parser_t   parser_bbb;
 298 parser_t   parser_mbed;
 299
 300 // Serial IRQ
 301 sirq_t    *sirq_dbg;
 302 sirq_t    *sirq_bbb;
 303 sirq_t    *sirq_mbed;
 304
 305 // Timer DMA
 306 tdma_t    *tdma_evt;
 307 tdma_t    *tdma_rcv;
 308 tdma_t    *tdma_xmt;
 309
 310 /*********
 311  * Tasks *
 312  *********/
 313
 314 void task_serial(uint64_t local, uint64_t world)
 315 {
 316         while (sirq_ready(sirq_dbg)) {
 317                 //sirq_printf("serial recv - dbg\r\n");
 318                 serial_receive(&parser_dbg,  sirq_getc(sirq_dbg));
 319         }
 320
 321         while (sirq_ready(sirq_bbb)) {
 322                 //sirq_printf("serial recv - bbb\r\n");
 323                 serial_receive(&parser_bbb,  sirq_getc(sirq_bbb));
 324         }
 325
 326         while (sirq_ready(sirq_mbed)) {
 327                 //sirq_printf("serial recv - mbed\r\n");
 328                 serial_receive(&parser_mbed, sirq_getc(sirq_mbed));
 329         }
 330 }
 331
 332 void task_events(uint64_t local, uint64_t world)
 333 {
 334         uint64_t event = 0;
 335
 336 #ifdef VERBOSE
 337         if (tdma_stamp(tdma_evt, &event)) {
 338                 sirq_printf("event received - evt\r\n");
 339         if (tdma_stamp(tdma_rcv, &event))
 340                 sirq_printf("event received - rcv\r\n");
 341         if (tdma_stamp(tdma_xmt, &event))
 342                 sirq_printf("event received - xmt\r\n");
 343 #endif
 344
 345         if (tdma_stamp(tdma_evt, &event))
 346                 serial_send_event(0, event);
 347         tdma_reset(tdma_evt);
 348 }
 349
 350 void task_sync(uint64_t local, uint64_t world)
 351 {
 352         serial_send_sync(sirq_bbb, local);
 353 }
 354
 355 void task_leds(uint64_t local, uint64_t world)
 356 {
 357         static uint32_t which = 0;
 358         led1 = (which == 0);
 359         led2 = (which == 1);
 360         which ^= 1;
 361 }
 362
 363 void task_debug(uint64_t local, uint64_t world)
 364 {
 365         //tdma_debug(tdma_rcv);
 366         sirq_printf("background - %6d.%02d -> %d.%02d\r\n",
 367                         (uint32_t)(local / NSEC_PER_SEC),
 368                         (uint32_t)(local % NSEC_PER_SEC / 10000000),
 369                         (uint32_t)(world / NSEC_PER_SEC),
 370                         (uint32_t)(world % NSEC_PER_SEC / 10000000));
 371 }
 372
 373 /********
 374  * Main *
 375  ********/
 376
 377 #define N_ELEM(x) (sizeof(x) / sizeof((x)[0]))
 378
 379 extern void test_main(void);
 380 extern serial_t stdio_uart;
 381
 382 static struct {
 383         void (*task)(uint64_t, uint64_t);
 384         uint64_t period;
 385         uint64_t due;
 386 } tasks[] = {
 387         { task_serial, 0          }, // always
 388         { task_events, 1000000000 }, // always
 389         { task_sync,   0          }, // always
 390         { task_leds,   100000000  }, // 10hz
 391         { task_debug,  1000000000 }, // 1hz
 392 };
 393
 394 void background(void)
 395 {
 396         // Debugging
 397         uint64_t local = tdma_time();
 398         uint64_t world = time_to_world(local);
 399
 400         // Run the scheduler
 401         for (unsigned i = 0; i < N_ELEM(tasks); i++) {
 402                 if (local >= tasks[i].due) {
 403                         tasks[i].task(local, world);
 404                         tasks[i].due += tasks[i].period;
 405                 }
 406         }
 407 }
 408
 409 int main(int argc, char **argv)
 410 {
 411         tdma_init();
 412
 413         // Open serial ports
 414         sirq_dbg   = sirq_open(SIRQ_UART0, USBTX, USBRX, 115200); // to pc
 415         sirq_bbb   = sirq_open(SIRQ_UART1, PTD3,  PTD2,  115200); // to bbb
 416         sirq_mbed  = sirq_open(SIRQ_UART2, PTE0,  PTE1,  115200); // to mbed
 417
 418
 419         // Setup timers
 420         tdma_evt   = tdma_open(TDMA_CHAN0, 3, PTC9,  PullDown); // async event
 421
 422         // mbed time sync
 423         tdma_rcv   = tdma_open(TDMA_CHAN2, 3, PTD2,  PullUp);   // time sync rcv
 424         tdma_xmt   = tdma_open(TDMA_CHAN3, 3, PTD3,  PullUp);   // time sync xmt
 425
 426         // host time sync
 427         //tdma_rcv   = tdma_open(TDMA_CHAN2, 2, USBRX, PullUp); // time sync rcv
 428         //tdma_xmt   = tdma_open(TDMA_CHAN3, 2, USBTX, PullUp); // time sync xmt
 429
 430         // Serial timestamping
 431         serial_tdma_rcv = tdma_rcv;
 432         serial_tdma_xmt = tdma_xmt;
 433
 434         // Run background loop
 435         printf("hello");
 436         while (true)
 437                 background();
 438
 439         // Run tests
 440         //test_main();
 441
 442         return 0;
 443 }