git.sur5r.net Git - freertos/blob - FreeRTOS/Demo/Flshlite/serial/serial.c

   1 /*\r
   2     FreeRTOS V7.2.0 - Copyright (C) 2012 Real Time Engineers Ltd.\r
   3         \r
   4 \r
   5     ***************************************************************************\r
   6      *                                                                       *\r
   7      *    FreeRTOS tutorial books are available in pdf and paperback.        *\r
   8      *    Complete, revised, and edited pdf reference manuals are also       *\r
   9      *    available.                                                         *\r
  10      *                                                                       *\r
  11      *    Purchasing FreeRTOS documentation will not only help you, by       *\r
  12      *    ensuring you get running as quickly as possible and with an        *\r
  13      *    in-depth knowledge of how to use FreeRTOS, it will also help       *\r
  14      *    the FreeRTOS project to continue with its mission of providing     *\r
  15      *    professional grade, cross platform, de facto standard solutions    *\r
  16      *    for microcontrollers - completely free of charge!                  *\r
  17      *                                                                       *\r
  18      *    >>> See http://www.FreeRTOS.org/Documentation for details. <<<     *\r
  19      *                                                                       *\r
  20      *    Thank you for using FreeRTOS, and thank you for your support!      *\r
  21      *                                                                       *\r
  22     ***************************************************************************\r
  23 \r
  24 \r
  25     This file is part of the FreeRTOS distribution.\r
  26 \r
  27     FreeRTOS is free software; you can redistribute it and/or modify it under\r
  28     the terms of the GNU General Public License (version 2) as published by the\r
  29     Free Software Foundation AND MODIFIED BY the FreeRTOS exception.\r
  30     >>>NOTE<<< The modification to the GPL is included to allow you to\r
  31     distribute a combined work that includes FreeRTOS without being obliged to\r
  32     provide the source code for proprietary components outside of the FreeRTOS\r
  33     kernel.  FreeRTOS is distributed in the hope that it will be useful, but\r
  34     WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY\r
  35     or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for\r
  36     more details. You should have received a copy of the GNU General Public\r
  37     License and the FreeRTOS license exception along with FreeRTOS; if not it\r
  38     can be viewed here: http://www.freertos.org/a00114.html and also obtained\r
  39     by writing to Richard Barry, contact details for whom are available on the\r
  40     FreeRTOS WEB site.\r
  41 \r
  42     1 tab == 4 spaces!\r
  43     \r
  44     ***************************************************************************\r
  45      *                                                                       *\r
  46      *    Having a problem?  Start by reading the FAQ "My application does   *\r
  47      *    not run, what could be wrong?                                      *\r
  48      *                                                                       *\r
  49      *    http://www.FreeRTOS.org/FAQHelp.html                               *\r
  50      *                                                                       *\r
  51     ***************************************************************************\r
  52 \r
  53     \r
  54     http://www.FreeRTOS.org - Documentation, training, latest information, \r
  55     license and contact details.\r
  56     \r
  57     http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,\r
  58     including FreeRTOS+Trace - an indispensable productivity tool.\r
  59 \r
  60     Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell \r
  61     the code with commercial support, indemnification, and middleware, under \r
  62     the OpenRTOS brand: http://www.OpenRTOS.com.  High Integrity Systems also\r
  63     provide a safety engineered and independently SIL3 certified version under \r
  64     the SafeRTOS brand: http://www.SafeRTOS.com.\r
  65 */\r
  66 \r
  67 /*\r
  68 Changes from V1.00:\r
  69         \r
  70         + Call to the more efficient portSWITCH_CONTEXT() replaces the call to \r
  71           taskYIELD() in the ISR.\r
  72 \r
  73 Changes from V1.01:\r
  74 \r
  75         + The semaphore task is not operational.  This does nothing but check\r
  76           the semaphore from ISR functionality.\r
  77         + ISR modified slightly so only Rx or Tx is serviced per ISR - not both.\r
  78 \r
  79 Changes from V1.2.0:\r
  80 \r
  81         + Change so Tx uses a DMA channel, and Rx uses an interrupt.\r
  82 \r
  83 Changes from V1.2.3\r
  84 \r
  85         + The function xPortInitMinimal() has been renamed to \r
  86           xSerialPortInitMinimal() and the function xPortInit() has been renamed\r
  87           to xSerialPortInit().\r
  88 \r
  89 Changes from V1.2.5\r
  90 \r
  91         + Reverted back to the non-DMA serial port driver, with a slightly modified\r
  92           ISR.  This is a better test of the scheduler mechanisms.\r
  93         + A critical section is now used in vInterruptOn().\r
  94         + Flag sTxInterruptOn has been added to the port structure.  This allows\r
  95           checking of the interrupt enable status without performing any IO.\r
  96 \r
  97 Changes from V2.0.0\r
  98 \r
  99         + Use portTickType in place of unsigned pdLONG for delay periods.\r
 100         + Slightly more efficient vSerialSendString() implementation.\r
 101         + cQueueReieveFromISR() used in place of xQueueReceive() in ISR.\r
 102 */\r
 103 \r
 104 #include <stdlib.h>\r
 105 #include <dos.h>\r
 106 #include "FreeRTOS.h"\r
 107 #include "queue.h"\r
 108 #include "task.h"\r
 109 #include "portasm.h"\r
 110 #include "semphr.h"\r
 111 \r
 112 #define serMAX_PORTS                    ( ( unsigned short ) 2 )\r
 113 \r
 114 #define serPORT_0_INT_REG               ( 0xff44 )\r
 115 #define serPORT_0_BAUD_REG              ( 0xff88 )\r
 116 #define serPORT_0_RX_REG                ( 0xff86 )\r
 117 #define serPORT_0_TX_REG                ( 0xff84 )\r
 118 #define serPORT_0_STATUS_REG    ( 0xff82 )\r
 119 #define serPORT_0_CTRL_REG              ( 0xff80 )\r
 120 #define serPORT_0_IRQ                   ( 0x14 )\r
 121 \r
 122 #define serPORT_1_INT_REG               ( 0xff42 )\r
 123 #define serPORT_1_BAUD_REG              ( 0xff18 )\r
 124 #define serPORT_1_RX_REG                ( 0xff16 )\r
 125 #define serPORT_1_TX_REG                ( 0xff14 )\r
 126 #define serPORT_1_STATUS_REG    ( 0xff12 )\r
 127 #define serPORT_1_CTRL_REG              ( 0xff10 )\r
 128 #define serPORT_1_IRQ                   ( 0x11 )\r
 129 \r
 130 #define serTX_EMPTY                             ( ( unsigned short ) 0x40 )\r
 131 #define serRX_READY                             ( ( unsigned short ) 0x80 )\r
 132 \r
 133 #define serRESET_PIC( usEOI_TYPE )      portOUTPUT_WORD( ( unsigned short ) 0xff22, usEOI_TYPE )\r
 134 #define serTX_HOLD_EMPTY_INT            ( ( unsigned short ) 0x100 )\r
 135 \r
 136 #define serENABLE_INTERRUPTS            ( ( unsigned short ) 0x80 )\r
 137 #define serMODE                                         ( ( unsigned short ) 0x01 )\r
 138 #define serENABLE_TX_MACHINES           ( ( unsigned short ) 0x40 )\r
 139 #define serENABLE_RX_MACHINES           ( ( unsigned short ) 0x20 )\r
 140 #define serINTERRUPT_MASK                       ( ( unsigned short ) 0x08 )\r
 141 #define serCLEAR_ALL_STATUS_BITS        ( ( unsigned short ) 0x00 )\r
 142 #define serINTERRUPT_PRIORITY           ( ( unsigned short ) 0x01 ) /*< Just below the scheduler priority. */\r
 143 \r
 144 #define serDONT_BLOCK                           ( ( portTickType ) 0 )\r
 145 \r
 146 typedef enum\r
 147 { \r
 148         serCOM1 = 0, \r
 149         serCOM2, \r
 150         serCOM3, \r
 151         serCOM4, \r
 152         serCOM5, \r
 153         serCOM6, \r
 154         serCOM7, \r
 155         serCOM8 \r
 156 } eCOMPort;\r
 157 \r
 158 typedef enum \r
 159 { \r
 160         serNO_PARITY, \r
 161         serODD_PARITY, \r
 162         serEVEN_PARITY, \r
 163         serMARK_PARITY, \r
 164         serSPACE_PARITY \r
 165 } eParity;\r
 166 \r
 167 typedef enum \r
 168 { \r
 169         serSTOP_1, \r
 170         serSTOP_2 \r
 171 } eStopBits;\r
 172 \r
 173 typedef enum \r
 174 { \r
 175         serBITS_5, \r
 176         serBITS_6, \r
 177         serBITS_7, \r
 178         serBITS_8 \r
 179 } eDataBits;\r
 180 \r
 181 typedef enum \r
 182 { \r
 183         ser50 = 0,\r
 184         ser75,          \r
 185         ser110,         \r
 186         ser134,         \r
 187         ser150,    \r
 188         ser200,\r
 189         ser300,         \r
 190         ser600,         \r
 191         ser1200,        \r
 192         ser1800,        \r
 193         ser2400,   \r
 194         ser4800,\r
 195         ser9600,                \r
 196         ser19200,       \r
 197         ser38400,       \r
 198         ser57600,       \r
 199         ser115200\r
 200 } eBaud;\r
 201 \r
 202 /* Must be same order as eBaud definitions. */\r
 203 static const unsigned short usBaudRateDivisor[] = \r
 204 {\r
 205         0, /* Not sure if the first 6 are correct.  First cannot be used. */\r
 206         29127,\r
 207         19859,\r
 208         16302,\r
 209         14564,\r
 210         10923,  \r
 211         6879,\r
 212         3437,\r
 213         1718,\r
 214         1145,\r
 215         859,\r
 216         429,\r
 217         214,\r
 218         107,\r
 219         54,\r
 220         35,\r
 221         18\r
 222 };\r
 223 \r
 224 \r
 225 typedef struct xCOM_PORT\r
 226 {\r
 227         /* Hardware parameters for this port. */\r
 228         short sTxInterruptOn;\r
 229         unsigned short usIntReg;\r
 230         unsigned short usBaudReg;\r
 231         unsigned short usRxReg;\r
 232         unsigned short usTxReg;\r
 233         unsigned short usStatusReg;\r
 234         unsigned short usCtrlReg;\r
 235 \r
 236         unsigned short usIRQVector;\r
 237 \r
 238         /* Queues used for communications with com test task. */\r
 239         xQueueHandle xRxedChars; \r
 240         xQueueHandle xCharsForTx;\r
 241 \r
 242         /* This semaphore does nothing useful except test a feature of the\r
 243         scheduler. */\r
 244         xSemaphoreHandle xTestSem;\r
 245 \r
 246 } xComPort;\r
 247 \r
 248 static xComPort xPorts[ serMAX_PORTS ] = \r
 249 {\r
 250         { pdFALSE, serPORT_0_INT_REG, serPORT_0_BAUD_REG, serPORT_0_RX_REG, serPORT_0_TX_REG, serPORT_0_STATUS_REG, serPORT_0_CTRL_REG, serPORT_0_IRQ, NULL, NULL, NULL },\r
 251         { pdFALSE, serPORT_1_INT_REG, serPORT_1_BAUD_REG, serPORT_1_RX_REG, serPORT_1_TX_REG, serPORT_1_STATUS_REG, serPORT_1_CTRL_REG, serPORT_1_IRQ, NULL, NULL, NULL }\r
 252 };\r
 253 \r
 254 typedef xComPort * xComPortHandle;\r
 255 \r
 256 /* These prototypes are repeated here so we don't have to include the serial header.  This allows\r
 257 the xComPortHandle structure details to be private to this file. */\r
 258 xComPortHandle xSerialPortInit( eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits, unsigned portBASE_TYPE uxBufferLength );\r
 259 portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, char *pcRxedChar, portTickType xBlockTime );\r
 260 portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, char cOutChar, portTickType xBlockTime );\r
 261 void vSerialClose( xComPortHandle xPort );\r
 262 short sSerialWaitForSemaphore( xComPortHandle xPort );\r
 263 /*-----------------------------------------------------------*/\r
 264 \r
 265 static short xComPortISR( xComPort * const pxPort );\r
 266 \r
 267 #define vInterruptOn( pxPort, usInterrupt )                                                                             \\r
 268 {                                                                                                                                                               \\r
 269 unsigned short usIn;                                                                                                            \\r
 270                                                                                                                                                                 \\r
 271         portENTER_CRITICAL();                                                                                                           \\r
 272         {                                                                                                                                                       \\r
 273                 if( pxPort->sTxInterruptOn == pdFALSE )                                                                 \\r
 274                 {                                                                                                                                               \\r
 275                         usIn = portINPUT_WORD( pxPort->usCtrlReg );                                                     \\r
 276                         portOUTPUT_WORD( pxPort->usCtrlReg, usIn | usInterrupt );                       \\r
 277                                                                                                                                                                 \\r
 278                         pxPort->sTxInterruptOn = pdTRUE;                                                                        \\r
 279                 }                                                                                                                                               \\r
 280         }                                                                                                                                                       \\r
 281         portEXIT_CRITICAL();                                                                                                                    \\r
 282 }                                                                                                                                                               \r
 283 /*-----------------------------------------------------------*/\r
 284 \r
 285 #define vInterruptOff( pxPort, usInterrupt )                                                                    \\r
 286 {                                                                                                                                                               \\r
 287         unsigned short usIn = portINPUT_WORD( pxPort->usCtrlReg );                              \\r
 288         if( usIn & usInterrupt )                                                                                                        \\r
 289         {                                                                                                                                                       \\r
 290                 portOUTPUT_WORD( pxPort->usCtrlReg, usIn & ~usInterrupt);                               \\r
 291                 pxPort->sTxInterruptOn = pdFALSE;                                                                               \\r
 292         }                                                                                                                                                       \\r
 293 }\r
 294 /*-----------------------------------------------------------*/\r
 295 \r
 296 \r
 297 /* Define an interrupt handler for each port */\r
 298 #define COM_IRQ_WRAPPER(N)                                                                              \\r
 299         static void __interrupt COM_IRQ##N##_WRAPPER( void )            \\r
 300         {                                                                                                                       \\r
 301         if( xComPortISR( &( xPorts[##N##] ) ) )                 \\r
 302         {                                                       \\r
 303                         portSWITCH_CONTEXT();                             \\r
 304                 }                                                       \\r
 305         }\r
 306 \r
 307   \r
 308 \r
 309 COM_IRQ_WRAPPER( 0 )\r
 310 COM_IRQ_WRAPPER( 1 )\r
 311 \r
 312 static pxISR xISRs[ serMAX_PORTS ] = \r
 313 {\r
 314         COM_IRQ0_WRAPPER, \r
 315         COM_IRQ1_WRAPPER\r
 316 };\r
 317 \r
 318 /*-----------------------------------------------------------*/\r
 319 \r
 320 xComPortHandle xSerialPortInit( eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits, unsigned portBASE_TYPE uxBufferLength )\r
 321 {\r
 322 unsigned short usPort;\r
 323 xComPortHandle pxPort = NULL;\r
 324 \r
 325 /* BAUDDIV = ( Microprocessor Clock / Baud Rate ) / 16 */\r
 326 \r
 327         /* Only n, 8, 1 is supported so these parameters are not required for this\r
 328         port. */\r
 329         ( void ) eWantedParity;\r
 330         ( void ) eWantedDataBits;\r
 331     ( void ) eWantedStopBits;\r
 332 \r
 333         /* Currently only n,8,1 is supported. */\r
 334 \r
 335         usPort = ( unsigned short ) ePort;\r
 336         \r
 337         if( usPort < serMAX_PORTS )\r
 338         {\r
 339                 pxPort = &( xPorts[ usPort ] );\r
 340 \r
 341                 portENTER_CRITICAL();\r
 342                 {\r
 343                         unsigned short usInWord;\r
 344 \r
 345                         /* Create the queues used by the com test task. */\r
 346                         pxPort->xRxedChars = xQueueCreate( uxBufferLength, ( unsigned portBASE_TYPE ) sizeof( char ) );\r
 347                         pxPort->xCharsForTx = xQueueCreate( uxBufferLength, ( unsigned portBASE_TYPE ) sizeof( char ) );\r
 348 \r
 349                         /* Create the test semaphore.  This does nothing useful except test a feature of the scheduler. */\r
 350                         vSemaphoreCreateBinary( pxPort->xTestSem );\r
 351 \r
 352                         /* There is no ISR here already to restore later. */\r
 353                         _dos_setvect( ( short ) pxPort->usIRQVector, xISRs[ usPort ] );\r
 354 \r
 355                         usInWord = portINPUT_WORD( pxPort->usIntReg );\r
 356                         usInWord &= ~serINTERRUPT_MASK;\r
 357                         usInWord |= serINTERRUPT_PRIORITY;\r
 358                         portOUTPUT_WORD( pxPort->usIntReg, usInWord );\r
 359 \r
 360                         portOUTPUT_WORD( pxPort->usBaudReg, usBaudRateDivisor[ eWantedBaud ] );\r
 361                         portOUTPUT_WORD( pxPort->usCtrlReg, serENABLE_INTERRUPTS | serMODE | serENABLE_TX_MACHINES | serENABLE_RX_MACHINES );\r
 362 \r
 363                         portOUTPUT_WORD( pxPort->usStatusReg, serCLEAR_ALL_STATUS_BITS );\r
 364                 }\r
 365                 portEXIT_CRITICAL();\r
 366         }\r
 367 \r
 368         return pxPort;\r
 369 } /*lint !e715 Some parameters are not used as only a subset of the serial port functionality is currently implemented. */\r
 370 /*-----------------------------------------------------------*/\r
 371 \r
 372 void vSerialPutString( xComPortHandle pxPort, const char * const pcString, unsigned short usStringLength )\r
 373 {\r
 374 unsigned short usByte;\r
 375 char *pcNextChar;\r
 376 \r
 377         pcNextChar = ( char * ) pcString;\r
 378 \r
 379         for( usByte = 0; usByte < usStringLength; usByte++ )\r
 380         {\r
 381                 xQueueSend( pxPort->xCharsForTx, pcNextChar, serDONT_BLOCK );\r
 382                 pcNextChar++;\r
 383         }\r
 384 \r
 385         vInterruptOn( pxPort, serTX_HOLD_EMPTY_INT );\r
 386 }\r
 387 /*-----------------------------------------------------------*/\r
 388 \r
 389 portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, char *pcRxedChar, portTickType xBlockTime )\r
 390 {\r
 391         /* Get the next character from the buffer, note that this routine is only \r
 392         called having checked that the is (at least) one to get */\r
 393         if( xQueueReceive( pxPort->xRxedChars, pcRxedChar, xBlockTime ) )\r
 394         {\r
 395                 return pdTRUE;\r
 396         }\r
 397         else\r
 398         {\r
 399                 return pdFALSE;\r
 400         }\r
 401 }\r
 402 /*-----------------------------------------------------------*/\r
 403 \r
 404 portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, char cOutChar, portTickType xBlockTime )\r
 405 {\r
 406         if( xQueueSend( pxPort->xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )\r
 407         {\r
 408                 return pdFAIL;\r
 409         }\r
 410 \r
 411         vInterruptOn( pxPort, serTX_HOLD_EMPTY_INT );\r
 412 \r
 413         return pdPASS;\r
 414 }\r
 415 /*-----------------------------------------------------------*/\r
 416 \r
 417 portBASE_TYPE xSerialWaitForSemaphore( xComPortHandle xPort )\r
 418 {\r
 419 const portTickType xBlockTime = ( portTickType ) 0xffff;\r
 420 \r
 421         /* This function does nothing interesting, but test the \r
 422         semaphore from ISR mechanism. */\r
 423         return xSemaphoreTake( xPort->xTestSem, xBlockTime );\r
 424 }\r
 425 /*-----------------------------------------------------------*/\r
 426 \r
 427 void vSerialClose( xComPortHandle xPort )\r
 428 {\r
 429 unsigned short usOutput;\r
 430 \r
 431         /* Turn off the interrupts.  We may also want to delete the queues and/or\r
 432         re-install the original ISR. */\r
 433 \r
 434         portENTER_CRITICAL();\r
 435         {\r
 436                 usOutput = portINPUT_WORD( xPort->usCtrlReg );\r
 437 \r
 438                 usOutput &= ~serENABLE_INTERRUPTS;\r
 439                 usOutput &= ~serENABLE_TX_MACHINES;\r
 440                 usOutput &= ~serENABLE_RX_MACHINES;\r
 441                 portOUTPUT_WORD( xPort->usCtrlReg, usOutput );\r
 442 \r
 443                 usOutput = portINPUT_WORD( xPort->usIntReg );\r
 444                 usOutput |= serINTERRUPT_MASK;\r
 445                 portOUTPUT_WORD( xPort->usIntReg, usOutput );\r
 446         }\r
 447         portEXIT_CRITICAL();\r
 448 }\r
 449 /*-----------------------------------------------------------*/\r
 450 \r
 451 static portBASE_TYPE xComPortISR( xComPort * const pxPort )\r
 452 {\r
 453 unsigned short usStatusRegister;\r
 454 char cChar;\r
 455 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE, xContinue = pdTRUE;\r
 456 \r
 457         /* NOTE:  THIS IS NOT AN EFFICIENT ISR AS IT IS DESIGNED SOLELY TO TEST\r
 458         THE SCHEDULER FUNCTIONALITY.  REAL APPLICATIONS SHOULD NOT USE THIS\r
 459         FUNCTION. */\r
 460 \r
 461 \r
 462         while( xContinue == pdTRUE )\r
 463         {\r
 464                 xContinue = pdFALSE;\r
 465                 usStatusRegister = portINPUT_WORD( pxPort->usStatusReg );\r
 466 \r
 467                 if( usStatusRegister & serRX_READY )\r
 468                 {\r
 469                         cChar = ( char ) portINPUT_WORD( pxPort->usRxReg );\r
 470                         xQueueSendFromISR( pxPort->xRxedChars, &cChar, &xHigherPriorityTaskWoken );\r
 471 \r
 472                         /* Also release the semaphore - this does nothing interesting and is just a test. */\r
 473                         xSemaphoreGiveFromISR( pxPort->xTestSem, &xHigherPriorityTaskWoken );\r
 474 \r
 475                         /* We have performed an action this cycle - there may be other to perform. */\r
 476                         xContinue = pdTRUE;\r
 477                 }\r
 478 \r
 479                 if( pxPort->sTxInterruptOn && ( usStatusRegister & serTX_EMPTY ) )\r
 480                 {\r
 481                         if( xQueueReceiveFromISR( pxPort->xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )\r
 482                         {\r
 483                                 portOUTPUT_WORD( pxPort->usTxReg, ( unsigned short ) cChar );\r
 484 \r
 485                                 /* We have performed an action this cycle - there may be others to perform. */\r
 486                                 xContinue = pdTRUE;\r
 487                         }\r
 488                         else\r
 489                         {\r
 490                                 /* Queue empty, nothing to send */\r
 491                                 vInterruptOff( pxPort, serTX_HOLD_EMPTY_INT );\r
 492                         }\r
 493                 }\r
 494         }\r
 495 \r
 496         serRESET_PIC( pxPort->usIRQVector );\r
 497 \r
 498         /* If posting to the queue woke a task that was blocked on the queue we may\r
 499         want to switch to the woken task - depending on its priority relative to\r
 500         the task interrupted by this ISR. */\r
 501         return xHigherPriorityTaskWoken;\r
 502 }\r
 503 \r
 504 \r
 505 \r
 506 \r
 507 \r
 508 \r