begriffs open source - freertos/blob - portable/MPLAB/PIC24_dsPIC/port.c

   1 /*
   2  * FreeRTOS Kernel <DEVELOPMENT BRANCH>
   3  * Copyright (C) 2021 Amazon.com, Inc. or its affiliates. All Rights Reserved.
   4  *
   5  * SPDX-License-Identifier: MIT
   6  *
   7  * Permission is hereby granted, free of charge, to any person obtaining a copy of
   8  * this software and associated documentation files (the "Software"), to deal in
   9  * the Software without restriction, including without limitation the rights to
  10  * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
  11  * the Software, and to permit persons to whom the Software is furnished to do so,
  12  * subject to the following conditions:
  13  *
  14  * The above copyright notice and this permission notice shall be included in all
  15  * copies or substantial portions of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  18  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
  19  * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
  20  * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
  21  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  22  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  23  *
  24  * https://www.FreeRTOS.org
  25  * https://github.com/FreeRTOS
  26  *
  27  */
  28
  29 /*
  30     Changes from V4.2.1
  31
  32     + Introduced the configKERNEL_INTERRUPT_PRIORITY definition.
  33 */
  34
  35 /*-----------------------------------------------------------
  36  * Implementation of functions defined in portable.h for the PIC24 port.
  37  *----------------------------------------------------------*/
  38
  39 /* Scheduler include files. */
  40 #include "FreeRTOS.h"
  41 #include "task.h"
  42
  43 /* Hardware specifics. */
  44 #define portBIT_SET 1
  45 #define portTIMER_PRESCALE 8
  46 #define portINITIAL_SR  0
  47
  48 /* Defined for backward compatibility with project created prior to
  49 FreeRTOS.org V4.3.0. */
  50 #ifndef configKERNEL_INTERRUPT_PRIORITY
  51     #define configKERNEL_INTERRUPT_PRIORITY 1
  52 #endif
  53
  54 /* Use _T1Interrupt as the interrupt handler name if the application writer has
  55 not provided their own. */
  56 #ifndef configTICK_INTERRUPT_HANDLER
  57     #define configTICK_INTERRUPT_HANDLER _T1Interrupt
  58 #endif /* configTICK_INTERRUPT_HANDLER */
  59
  60 /* The program counter is only 23 bits. */
  61 #define portUNUSED_PR_BITS  0x7f
  62
  63 /* Records the nesting depth of calls to portENTER_CRITICAL(). */
  64 UBaseType_t uxCriticalNesting = 0xef;
  65
  66 #if configKERNEL_INTERRUPT_PRIORITY != 1
  67     #error If configKERNEL_INTERRUPT_PRIORITY is not 1 then the #32 in the following macros needs changing to equal the portINTERRUPT_BITS value, which is ( configKERNEL_INTERRUPT_PRIORITY << 5 )
  68 #endif
  69
  70 #if defined( __PIC24E__ ) || defined ( __PIC24F__ ) || defined( __PIC24FK__ ) || defined( __PIC24H__ )
  71
  72     #ifdef __HAS_EDS__
  73         #define portRESTORE_CONTEXT()                                                                                       \
  74                     asm volatile(   "MOV    _pxCurrentTCB, W0       \n" /* Restore the stack pointer for the task. */       \
  75                             "MOV    [W0], W15               \n"                                                             \
  76                             "POP    W0                      \n" /* Restore the critical nesting counter for the task. */    \
  77                             "MOV    W0, _uxCriticalNesting  \n"                                                             \
  78                             "POP    DSWPAG                  \n"                                                             \
  79                             "POP    DSRPAG                  \n"                                                             \
  80                             "POP    CORCON                  \n"                                                             \
  81                             "POP    TBLPAG                  \n"                                                             \
  82                             "POP    RCOUNT                  \n" /* Restore the registers from the stack. */                 \
  83                             "POP    W14                     \n"                                                             \
  84                             "POP.D  W12                     \n"                                                             \
  85                             "POP.D  W10                     \n"                                                             \
  86                             "POP.D  W8                      \n"                                                             \
  87                             "POP.D  W6                      \n"                                                             \
  88                             "POP.D  W4                      \n"                                                             \
  89                             "POP.D  W2                      \n"                                                             \
  90                             "POP.D  W0                      \n"                                                             \
  91                             "POP    SR                        " );
  92     #else /* __HAS_EDS__ */
  93         #define portRESTORE_CONTEXT()                                                                                       \
  94             asm volatile(   "MOV    _pxCurrentTCB, W0       \n" /* Restore the stack pointer for the task. */               \
  95                             "MOV    [W0], W15               \n"                                                             \
  96                             "POP    W0                      \n" /* Restore the critical nesting counter for the task. */    \
  97                             "MOV    W0, _uxCriticalNesting  \n"                                                             \
  98                             "POP    PSVPAG                  \n"                                                             \
  99                             "POP    CORCON                  \n"                                                             \
 100                             "POP    TBLPAG                  \n"                                                             \
 101                             "POP    RCOUNT                  \n" /* Restore the registers from the stack. */                 \
 102                             "POP    W14                     \n"                                                             \
 103                             "POP.D  W12                     \n"                                                             \
 104                             "POP.D  W10                     \n"                                                             \
 105                             "POP.D  W8                      \n"                                                             \
 106                             "POP.D  W6                      \n"                                                             \
 107                             "POP.D  W4                      \n"                                                             \
 108                             "POP.D  W2                      \n"                                                             \
 109                             "POP.D  W0                      \n"                                                             \
 110                             "POP    SR                        " );
 111         #endif /* __HAS_EDS__ */
 112 #endif /* defined( __PIC24E__ ) || defined ( __PIC24F__ ) || defined( __PIC24FK__ ) || defined( __PIC24H__ ) */
 113
 114 #if defined( __dsPIC30F__ ) || defined( __dsPIC33F__ )
 115
 116     #define portRESTORE_CONTEXT()                                                                                       \
 117         asm volatile(   "MOV    _pxCurrentTCB, W0       \n" /* Restore the stack pointer for the task. */               \
 118                         "MOV    [W0], W15               \n"                                                             \
 119                         "POP    W0                      \n" /* Restore the critical nesting counter for the task. */    \
 120                         "MOV    W0, _uxCriticalNesting  \n"                                                             \
 121                         "POP    PSVPAG                  \n"                                                             \
 122                         "POP    CORCON                  \n"                                                             \
 123                         "POP    DOENDH                  \n"                                                             \
 124                         "POP    DOENDL                  \n"                                                             \
 125                         "POP    DOSTARTH                \n"                                                             \
 126                         "POP    DOSTARTL                \n"                                                             \
 127                         "POP    DCOUNT                  \n"                                                             \
 128                         "POP    ACCBU                   \n"                                                             \
 129                         "POP    ACCBH                   \n"                                                             \
 130                         "POP    ACCBL                   \n"                                                             \
 131                         "POP    ACCAU                   \n"                                                             \
 132                         "POP    ACCAH                   \n"                                                             \
 133                         "POP    ACCAL                   \n"                                                             \
 134                         "POP    TBLPAG                  \n"                                                             \
 135                         "POP    RCOUNT                  \n" /* Restore the registers from the stack. */                 \
 136                         "POP    W14                     \n"                                                             \
 137                         "POP.D  W12                     \n"                                                             \
 138                         "POP.D  W10                     \n"                                                             \
 139                         "POP.D  W8                      \n"                                                             \
 140                         "POP.D  W6                      \n"                                                             \
 141                         "POP.D  W4                      \n"                                                             \
 142                         "POP.D  W2                      \n"                                                             \
 143                         "POP.D  W0                      \n"                                                             \
 144                         "POP    SR                        " );
 145
 146 #endif /* defined( __dsPIC30F__ ) || defined( __dsPIC33F__ ) */
 147
 148 #ifndef portRESTORE_CONTEXT
 149     #error Unrecognised device selected
 150
 151     /* Note:  dsPIC parts with EDS are not supported as there is no easy way to
 152     recover the hardware stacked copies for DOCOUNT, DOHIGH, DOLOW. */
 153 #endif
 154
 155 /*
 156  * Setup the timer used to generate the tick interrupt.
 157  */
 158 void vApplicationSetupTickTimerInterrupt( void );
 159
 160 /*
 161  * See header file for description.
 162  */
 163 StackType_t *pxPortInitialiseStack( StackType_t *pxTopOfStack, TaskFunction_t pxCode, void *pvParameters )
 164 {
 165 uint16_t usCode;
 166 UBaseType_t i;
 167
 168 const StackType_t xInitialStack[] =
 169 {
 170     0x1111, /* W1 */
 171     0x2222, /* W2 */
 172     0x3333, /* W3 */
 173     0x4444, /* W4 */
 174     0x5555, /* W5 */
 175     0x6666, /* W6 */
 176     0x7777, /* W7 */
 177     0x8888, /* W8 */
 178     0x9999, /* W9 */
 179     0xaaaa, /* W10 */
 180     0xbbbb, /* W11 */
 181     0xcccc, /* W12 */
 182     0xdddd, /* W13 */
 183     0xeeee, /* W14 */
 184     0xcdce, /* RCOUNT */
 185     0xabac, /* TBLPAG */
 186
 187     /* dsPIC specific registers. */
 188     #if defined( __dsPIC30F__ ) || defined( __dsPIC33F__ )
 189         0x0202, /* ACCAL */
 190         0x0303, /* ACCAH */
 191         0x0404, /* ACCAU */
 192         0x0505, /* ACCBL */
 193         0x0606, /* ACCBH */
 194         0x0707, /* ACCBU */
 195         0x0808, /* DCOUNT */
 196         0x090a, /* DOSTARTL */
 197         0x1010, /* DOSTARTH */
 198         0x1110, /* DOENDL */
 199         0x1212, /* DOENDH */
 200     #endif
 201 };
 202
 203     /* Setup the stack as if a yield had occurred.
 204
 205     Save the low bytes of the program counter. */
 206     usCode = ( uint16_t ) pxCode;
 207     *pxTopOfStack = ( StackType_t ) usCode;
 208     pxTopOfStack++;
 209
 210     /* Save the high byte of the program counter.  This will always be zero
 211     here as it is passed in a 16bit pointer.  If the address is greater than
 212     16 bits then the pointer will point to a jump table. */
 213     *pxTopOfStack = ( StackType_t ) 0;
 214     pxTopOfStack++;
 215
 216     /* Status register with interrupts enabled. */
 217     *pxTopOfStack = portINITIAL_SR;
 218     pxTopOfStack++;
 219
 220     /* Parameters are passed in W0. */
 221     *pxTopOfStack = ( StackType_t ) pvParameters;
 222     pxTopOfStack++;
 223
 224     for( i = 0; i < ( sizeof( xInitialStack ) / sizeof( StackType_t ) ); i++ )
 225     {
 226         *pxTopOfStack = xInitialStack[ i ];
 227         pxTopOfStack++;
 228     }
 229
 230     *pxTopOfStack = CORCON;
 231     pxTopOfStack++;
 232
 233     #if defined(__HAS_EDS__)
 234         *pxTopOfStack = DSRPAG;
 235         pxTopOfStack++;
 236         *pxTopOfStack = DSWPAG;
 237         pxTopOfStack++;
 238     #else /* __HAS_EDS__ */
 239         *pxTopOfStack = PSVPAG;
 240         pxTopOfStack++;
 241     #endif /* __HAS_EDS__ */
 242
 243     /* Finally the critical nesting depth. */
 244     *pxTopOfStack = 0x00;
 245     pxTopOfStack++;
 246
 247     return pxTopOfStack;
 248 }
 249 /*-----------------------------------------------------------*/
 250
 251 BaseType_t xPortStartScheduler( void )
 252 {
 253     /* Setup a timer for the tick ISR. */
 254     vApplicationSetupTickTimerInterrupt();
 255
 256     /* Restore the context of the first task to run. */
 257     portRESTORE_CONTEXT();
 258
 259     /* Simulate the end of the yield function. */
 260     asm volatile ( "return" );
 261
 262     /* Should not reach here. */
 263     return pdTRUE;
 264 }
 265 /*-----------------------------------------------------------*/
 266
 267 void vPortEndScheduler( void )
 268 {
 269     /* Not implemented in ports where there is nothing to return to.
 270     Artificially force an assert. */
 271     configASSERT( uxCriticalNesting == 1000UL );
 272 }
 273 /*-----------------------------------------------------------*/
 274
 275 /*
 276  * Setup a timer for a regular tick.
 277  */
 278 __attribute__(( weak )) void vApplicationSetupTickTimerInterrupt( void )
 279 {
 280 const uint32_t ulCompareMatch = ( ( configCPU_CLOCK_HZ / portTIMER_PRESCALE ) / configTICK_RATE_HZ ) - 1;
 281
 282     /* Prescale of 8. */
 283     T1CON = 0;
 284     TMR1 = 0;
 285
 286     PR1 = ( uint16_t ) ulCompareMatch;
 287
 288     /* Setup timer 1 interrupt priority. */
 289     IPC0bits.T1IP = configKERNEL_INTERRUPT_PRIORITY;
 290
 291     /* Clear the interrupt as a starting condition. */
 292     IFS0bits.T1IF = 0;
 293
 294     /* Enable the interrupt. */
 295     IEC0bits.T1IE = 1;
 296
 297     /* Setup the prescale value. */
 298     T1CONbits.TCKPS0 = 1;
 299     T1CONbits.TCKPS1 = 0;
 300
 301     /* Start the timer. */
 302     T1CONbits.TON = 1;
 303 }
 304 /*-----------------------------------------------------------*/
 305
 306 void vPortEnterCritical( void )
 307 {
 308     portDISABLE_INTERRUPTS();
 309     uxCriticalNesting++;
 310 }
 311 /*-----------------------------------------------------------*/
 312
 313 void vPortExitCritical( void )
 314 {
 315     configASSERT( uxCriticalNesting );
 316     uxCriticalNesting--;
 317     if( uxCriticalNesting == 0 )
 318     {
 319         portENABLE_INTERRUPTS();
 320     }
 321 }
 322 /*-----------------------------------------------------------*/
 323
 324 void __attribute__((__interrupt__, auto_psv)) configTICK_INTERRUPT_HANDLER( void )
 325 {
 326     /* Clear the timer interrupt. */
 327     IFS0bits.T1IF = 0;
 328
 329     if( xTaskIncrementTick() != pdFALSE )
 330     {
 331         portYIELD();
 332     }
 333 }
 334 /*-----------------------------------------------------------*/