/* | |
FreeRTOS.org V5.0.4 - Copyright (C) 2003-2008 Richard Barry. | |
This file is part of the FreeRTOS.org distribution. | |
FreeRTOS.org is free software; you can redistribute it and/or modify | |
it under the terms of the GNU General Public License as published by | |
the Free Software Foundation; either version 2 of the License, or | |
(at your option) any later version. | |
FreeRTOS.org is distributed in the hope that it will be useful, | |
but WITHOUT ANY WARRANTY; without even the implied warranty of | |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
GNU General Public License for more details. | |
You should have received a copy of the GNU General Public License | |
along with FreeRTOS.org; if not, write to the Free Software | |
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
A special exception to the GPL can be applied should you wish to distribute | |
a combined work that includes FreeRTOS.org, without being obliged to provide | |
the source code for any proprietary components. See the licensing section | |
of http://www.FreeRTOS.org for full details of how and when the exception | |
can be applied. | |
*************************************************************************** | |
*************************************************************************** | |
* * | |
* SAVE TIME AND MONEY! We can port FreeRTOS.org to your own hardware, * | |
* and even write all or part of your application on your behalf. * | |
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*************************************************************************** | |
*************************************************************************** | |
Please ensure to read the configuration and relevant port sections of the | |
online documentation. | |
http://www.FreeRTOS.org - Documentation, latest information, license and | |
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*/ | |
/* | |
Changes from V2.4.0 | |
+ Made serial ISR handling more complete and robust. | |
Changes from V2.4.1 | |
+ Split serial.c into serial.c and serialISR.c. serial.c can be | |
compiled using ARM or THUMB modes. serialISR.c must always be | |
compiled in ARM mode. | |
+ Another small change to cSerialPutChar(). | |
Changed from V2.5.1 | |
+ In cSerialPutChar() an extra check is made to ensure the post to | |
the queue was successful if then attempting to retrieve the posted | |
character. | |
*/ | |
/* | |
BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0. | |
This file contains all the serial port components that can be compiled to | |
either ARM or THUMB mode. Components that must be compiled to ARM mode are | |
contained in serialISR.c. | |
*/ | |
/* Standard includes. */ | |
#include <stdlib.h> | |
/* Scheduler includes. */ | |
#include "FreeRTOS.h" | |
#include "queue.h" | |
#include "task.h" | |
/* Demo application includes. */ | |
#include "serial.h" | |
/*-----------------------------------------------------------*/ | |
/* Constants to setup and access the UART. */ | |
#define serDLAB ( ( unsigned portCHAR ) 0x80 ) | |
#define serENABLE_INTERRUPTS ( ( unsigned portCHAR ) 0x03 ) | |
#define serNO_PARITY ( ( unsigned portCHAR ) 0x00 ) | |
#define ser1_STOP_BIT ( ( unsigned portCHAR ) 0x00 ) | |
#define ser8_BIT_CHARS ( ( unsigned portCHAR ) 0x03 ) | |
#define serFIFO_ON ( ( unsigned portCHAR ) 0x01 ) | |
#define serCLEAR_FIFO ( ( unsigned portCHAR ) 0x06 ) | |
#define serWANTED_CLOCK_SCALING ( ( unsigned portLONG ) 16 ) | |
/* Constants to setup and access the VIC. */ | |
#define serUART0_VIC_CHANNEL ( ( unsigned portLONG ) 0x0006 ) | |
#define serUART0_VIC_CHANNEL_BIT ( ( unsigned portLONG ) 0x0040 ) | |
#define serUART0_VIC_ENABLE ( ( unsigned portLONG ) 0x0020 ) | |
#define serCLEAR_VIC_INTERRUPT ( ( unsigned portLONG ) 0 ) | |
#define serINVALID_QUEUE ( ( xQueueHandle ) 0 ) | |
#define serHANDLE ( ( xComPortHandle ) 1 ) | |
#define serNO_BLOCK ( ( portTickType ) 0 ) | |
/*-----------------------------------------------------------*/ | |
/* Queues used to hold received characters, and characters waiting to be | |
transmitted. */ | |
static xQueueHandle xRxedChars; | |
static xQueueHandle xCharsForTx; | |
/*-----------------------------------------------------------*/ | |
/* Communication flag between the interrupt service routine and serial API. */ | |
static volatile portLONG *plTHREEmpty; | |
/* | |
* The queues are created in serialISR.c as they are used from the ISR. | |
* Obtain references to the queues and THRE Empty flag. | |
*/ | |
extern void vSerialISRCreateQueues( unsigned portBASE_TYPE uxQueueLength, xQueueHandle *pxRxedChars, xQueueHandle *pxCharsForTx, portLONG volatile **pplTHREEmptyFlag ); | |
/*-----------------------------------------------------------*/ | |
xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength ) | |
{ | |
unsigned portLONG ulDivisor, ulWantedClock; | |
xComPortHandle xReturn = serHANDLE; | |
extern void ( vUART_ISR_Wrapper )( void ); | |
/* The queues are used in the serial ISR routine, so are created from | |
serialISR.c (which is always compiled to ARM mode. */ | |
vSerialISRCreateQueues( uxQueueLength, &xRxedChars, &xCharsForTx, &plTHREEmpty ); | |
if( | |
( xRxedChars != serINVALID_QUEUE ) && | |
( xCharsForTx != serINVALID_QUEUE ) && | |
( ulWantedBaud != ( unsigned portLONG ) 0 ) | |
) | |
{ | |
portENTER_CRITICAL(); | |
{ | |
/* Setup the baud rate: Calculate the divisor value. */ | |
ulWantedClock = ulWantedBaud * serWANTED_CLOCK_SCALING; | |
ulDivisor = configCPU_CLOCK_HZ / ulWantedClock; | |
/* Set the DLAB bit so we can access the divisor. */ | |
UART0_LCR |= serDLAB; | |
/* Setup the divisor. */ | |
UART0_DLL = ( unsigned portCHAR ) ( ulDivisor & ( unsigned portLONG ) 0xff ); | |
ulDivisor >>= 8; | |
UART0_DLM = ( unsigned portCHAR ) ( ulDivisor & ( unsigned portLONG ) 0xff ); | |
/* Turn on the FIFO's and clear the buffers. */ | |
UART0_FCR = ( serFIFO_ON | serCLEAR_FIFO ); | |
/* Setup transmission format. */ | |
UART0_LCR = serNO_PARITY | ser1_STOP_BIT | ser8_BIT_CHARS; | |
/* Setup the VIC for the UART. */ | |
VICIntSelect &= ~( serUART0_VIC_CHANNEL_BIT ); | |
VICIntEnable |= serUART0_VIC_CHANNEL_BIT; | |
VICVectAddr1 = ( portLONG ) vUART_ISR_Wrapper; | |
VICVectCntl1 = serUART0_VIC_CHANNEL | serUART0_VIC_ENABLE; | |
/* Enable UART0 interrupts. */ | |
UART0_IER |= serENABLE_INTERRUPTS; | |
} | |
portEXIT_CRITICAL(); | |
} | |
else | |
{ | |
xReturn = ( xComPortHandle ) 0; | |
} | |
return xReturn; | |
} | |
/*-----------------------------------------------------------*/ | |
signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime ) | |
{ | |
/* The port handle is not required as this driver only supports UART0. */ | |
( void ) pxPort; | |
/* Get the next character from the buffer. Return false if no characters | |
are available, or arrive before xBlockTime expires. */ | |
if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) ) | |
{ | |
return pdTRUE; | |
} | |
else | |
{ | |
return pdFALSE; | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
void vSerialPutString( xComPortHandle pxPort, const signed portCHAR * const pcString, unsigned portSHORT usStringLength ) | |
{ | |
signed portCHAR *pxNext; | |
/* NOTE: This implementation does not handle the queue being full as no | |
block time is used! */ | |
/* The port handle is not required as this driver only supports UART0. */ | |
( void ) pxPort; | |
( void ) usStringLength; | |
/* Send each character in the string, one at a time. */ | |
pxNext = ( signed portCHAR * ) pcString; | |
while( *pxNext ) | |
{ | |
xSerialPutChar( pxPort, *pxNext, serNO_BLOCK ); | |
pxNext++; | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed portCHAR cOutChar, portTickType xBlockTime ) | |
{ | |
signed portBASE_TYPE xReturn; | |
/* This demo driver only supports one port so the parameter is not used. */ | |
( void ) pxPort; | |
portENTER_CRITICAL(); | |
{ | |
/* Is there space to write directly to the UART? */ | |
if( *plTHREEmpty == ( portLONG ) pdTRUE ) | |
{ | |
/* We wrote the character directly to the UART, so was | |
successful. */ | |
*plTHREEmpty = pdFALSE; | |
UART0_THR = cOutChar; | |
xReturn = pdPASS; | |
} | |
else | |
{ | |
/* We cannot write directly to the UART, so queue the character. | |
Block for a maximum of xBlockTime if there is no space in the | |
queue. */ | |
xReturn = xQueueSend( xCharsForTx, &cOutChar, xBlockTime ); | |
/* Depending on queue sizing and task prioritisation: While we | |
were blocked waiting to post interrupts were not disabled. It is | |
possible that the serial ISR has emptied the Tx queue, in which | |
case we need to start the Tx off again. */ | |
if( ( *plTHREEmpty == ( portLONG ) pdTRUE ) && ( xReturn == pdPASS ) ) | |
{ | |
xQueueReceive( xCharsForTx, &cOutChar, serNO_BLOCK ); | |
*plTHREEmpty = pdFALSE; | |
UART0_THR = cOutChar; | |
} | |
} | |
} | |
portEXIT_CRITICAL(); | |
return xReturn; | |
} | |
/*-----------------------------------------------------------*/ | |
void vSerialClose( xComPortHandle xPort ) | |
{ | |
/* Not supported as not required by the demo application. */ | |
( void ) xPort; | |
} | |
/*-----------------------------------------------------------*/ | |