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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [ARM7_LPC2106_GCC/] [serial/] [serialISR.c] - Blame information for rev 666

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1 577 jeremybenn
/*
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    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.
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    ***************************************************************************
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    *                                                                         *
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    * If you are:                                                             *
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    *                                                                         *
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    *    + New to FreeRTOS,                                                   *
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    *    + Wanting to learn FreeRTOS or multitasking in general quickly       *
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    *    + Looking for basic training,                                        *
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    *    + Wanting to improve your FreeRTOS skills and productivity           *
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    *                                                                         *
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    * then take a look at the FreeRTOS books - available as PDF or paperback  *
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    *                                                                         *
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    *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *
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    *                  http://www.FreeRTOS.org/Documentation                  *
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    *                                                                         *
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    * A pdf reference manual is also available.  Both are usually delivered   *
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    * to your inbox within 20 minutes to two hours when purchased between 8am *
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    * and 8pm GMT (although please allow up to 24 hours in case of            *
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    * exceptional circumstances).  Thank you for your support!                *
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    *                                                                         *
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    ***************************************************************************
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    This file is part of the FreeRTOS distribution.
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    FreeRTOS is free software; you can redistribute it and/or modify it under
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    the terms of the GNU General Public License (version 2) as published by the
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    Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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    ***NOTE*** The exception to the GPL is included to allow you to distribute
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    a combined work that includes FreeRTOS without being obliged to provide the
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    source code for proprietary components outside of the FreeRTOS kernel.
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    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
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    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
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    more details. You should have received a copy of the GNU General Public
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    License and the FreeRTOS license exception along with FreeRTOS; if not it
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    can be viewed here: http://www.freertos.org/a00114.html and also obtained
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    by writing to Richard Barry, contact details for whom are available on the
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    FreeRTOS WEB site.
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    1 tab == 4 spaces!
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    http://www.FreeRTOS.org - Documentation, latest information, license and
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    contact details.
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    http://www.SafeRTOS.com - A version that is certified for use in safety
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    critical systems.
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    http://www.OpenRTOS.com - Commercial support, development, porting,
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    licensing and training services.
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*/
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/*
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        BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
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        This file contains all the serial port components that must be compiled
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        to ARM mode.  The components that can be compiled to either ARM or THUMB
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        mode are contained in serial.c.
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*/
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/* Standard includes. */
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#include <stdlib.h>
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/* Scheduler includes. */
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#include "FreeRTOS.h"
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#include "queue.h"
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#include "task.h"
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/* Demo application includes. */
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#include "serial.h"
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/*-----------------------------------------------------------*/
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/* Constant to access the VIC. */
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#define serCLEAR_VIC_INTERRUPT                  ( ( unsigned long ) 0 )
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/* Constants to determine the ISR source. */
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#define serSOURCE_THRE                                  ( ( unsigned char ) 0x02 )
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#define serSOURCE_RX_TIMEOUT                    ( ( unsigned char ) 0x0c )
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#define serSOURCE_ERROR                                 ( ( unsigned char ) 0x06 )
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#define serSOURCE_RX                                    ( ( unsigned char ) 0x04 )
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#define serINTERRUPT_SOURCE_MASK                ( ( unsigned char ) 0x0f )
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/* Queues used to hold received characters, and characters waiting to be
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transmitted. */
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static xQueueHandle xRxedChars;
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static xQueueHandle xCharsForTx;
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static volatile long lTHREEmpty;
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/*-----------------------------------------------------------*/
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/*
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 * The queues are created in serialISR.c as they are used from the ISR.
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 * Obtain references to the queues and THRE Empty flag.
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 */
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void vSerialISRCreateQueues( unsigned portBASE_TYPE uxQueueLength, xQueueHandle *pxRxedChars, xQueueHandle *pxCharsForTx, long volatile **pplTHREEmptyFlag );
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/* UART0 interrupt service routine entry point. */
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void vUART_ISR_Wrapper( void ) __attribute__ ((naked));
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/* UART0 interrupt service routine handler. */
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void vUART_ISR_Handler( void ) __attribute__ ((noinline));
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/*-----------------------------------------------------------*/
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void vSerialISRCreateQueues(    unsigned portBASE_TYPE uxQueueLength, xQueueHandle *pxRxedChars,
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                                                                xQueueHandle *pxCharsForTx, long volatile **pplTHREEmptyFlag )
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{
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        /* Create the queues used to hold Rx and Tx characters. */
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        xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
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        xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
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        /* Pass back a reference to the queues so the serial API file can
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        post/receive characters. */
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        *pxRxedChars = xRxedChars;
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        *pxCharsForTx = xCharsForTx;
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        /* Initialise the THRE empty flag - and pass back a reference. */
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        lTHREEmpty = ( long ) pdTRUE;
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        *pplTHREEmptyFlag = &lTHREEmpty;
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}
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/*-----------------------------------------------------------*/
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void vUART_ISR_Wrapper( void )
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{
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        /* Save the context of the interrupted task. */
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        portSAVE_CONTEXT();
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        /* Call the handler.  This must be a separate function from the wrapper
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        to ensure the correct stack frame is set up. */
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        __asm volatile ("bl vUART_ISR_Handler");
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        /* Restore the context of whichever task is going to run next. */
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        portRESTORE_CONTEXT();
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}
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/*-----------------------------------------------------------*/
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void vUART_ISR_Handler( void )
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{
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signed char cChar;
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portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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        /* What caused the interrupt? */
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        switch( UART0_IIR & serINTERRUPT_SOURCE_MASK )
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        {
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                case serSOURCE_ERROR :  /* Not handling this, but clear the interrupt. */
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                                                                cChar = UART0_LSR;
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                                                                break;
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                case serSOURCE_THRE     :       /* The THRE is empty.  If there is another
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                                                                character in the Tx queue, send it now. */
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                                                                if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
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                                                                {
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                                                                        UART0_THR = cChar;
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                                                                }
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                                                                else
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                                                                {
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                                                                        /* There are no further characters
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                                                                        queued to send so we can indicate
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                                                                        that the THRE is available. */
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                                                                        lTHREEmpty = pdTRUE;
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                                                                }
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                                                                break;
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                case serSOURCE_RX_TIMEOUT :
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                case serSOURCE_RX       :       /* A character was received.  Place it in
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                                                                the queue of received characters. */
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                                                                cChar = UART0_RBR;
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                                                                xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
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                                                                break;
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                default                         :       /* There is nothing to do, leave the ISR. */
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                                                                break;
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        }
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        if( xHigherPriorityTaskWoken )
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        {
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                portYIELD_FROM_ISR();
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        }
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        /* Clear the ISR in the VIC. */
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        VICVectAddr = serCLEAR_VIC_INTERRUPT;
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}
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