/* | |
FreeRTOS.org V5.1.0 - Copyright (C) 2003-2008 Richard Barry. | |
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*************************************************************************** | |
*************************************************************************** | |
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*/ | |
/* | |
BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR USART0. | |
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" | |
#include "AT91R40008.h" | |
#include "usart.h" | |
#include "pio.h" | |
#include "aic.h" | |
/*-----------------------------------------------------------*/ | |
/* Constants to setup and access the UART. */ | |
#define portUSART0_AIC_CHANNEL ( ( unsigned portLONG ) 2 ) | |
#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; | |
/*-----------------------------------------------------------*/ | |
/* | |
* 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 ); | |
/*-----------------------------------------------------------*/ | |
xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength ) | |
{ | |
unsigned portLONG ulSpeed; | |
unsigned portLONG ulCD; | |
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 ); | |
if( | |
( xRxedChars != serINVALID_QUEUE ) && | |
( xCharsForTx != serINVALID_QUEUE ) && | |
( ulWantedBaud != ( unsigned portLONG ) 0 ) | |
) | |
{ | |
portENTER_CRITICAL(); | |
{ | |
/* Enable clock to USART0... */ | |
AT91C_BASE_PS->PS_PCER = AT91C_PS_US0; | |
/* Disable all USART0 interrupt sources to begin... */ | |
AT91C_BASE_US0->US_IDR = 0xFFFFFFFF; | |
/* Reset various status bits (just in case)... */ | |
AT91C_BASE_US0->US_CR = US_RSTSTA; | |
AT91C_BASE_PIO->PIO_PDR = TXD0 | RXD0; /* Enable RXD and TXD pins */ | |
AT91C_BASE_US0->US_CR = US_RSTRX | US_RSTTX | US_RXDIS | US_TXDIS; | |
/* Clear Transmit and Receive Counters */ | |
AT91C_BASE_US0->US_RCR = 0; | |
AT91C_BASE_US0->US_TCR = 0; | |
/* Input clock to baud rate generator is MCK */ | |
ulSpeed = configCPU_CLOCK_HZ * 10; | |
ulSpeed = ulSpeed / 16; | |
ulSpeed = ulSpeed / ulWantedBaud; | |
/* compute the error */ | |
ulCD = ulSpeed / 10; | |
if ((ulSpeed - (ulCD * 10)) >= 5) | |
ulCD++; | |
/* Define the baud rate divisor register */ | |
AT91C_BASE_US0->US_BRGR = ulCD; | |
/* Define the USART mode */ | |
AT91C_BASE_US0->US_MR = US_CLKS_MCK | US_CHRL_8 | US_PAR_NO | US_NBSTOP_1 | US_CHMODE_NORMAL; | |
/* Write the Timeguard Register */ | |
AT91C_BASE_US0->US_TTGR = 0; | |
/* Setup the interrupt for USART0. | |
Store interrupt handler function address in USART0 vector register... */ | |
AT91C_BASE_AIC->AIC_SVR[ portUSART0_AIC_CHANNEL ] = (unsigned long)vUART_ISR_Wrapper; | |
/* USART0 interrupt level-sensitive, priority 1... */ | |
AT91C_BASE_AIC->AIC_SMR[ portUSART0_AIC_CHANNEL ] = AIC_SRCTYPE_INT_LEVEL_SENSITIVE | 1; | |
/* Clear some pending USART0 interrupts (just in case)... */ | |
AT91C_BASE_US0->US_CR = US_RSTSTA; | |
/* Enable USART0 interrupt sources (but not Tx for now)... */ | |
AT91C_BASE_US0->US_IER = US_RXRDY; | |
/* Enable USART0 interrupts in the AIC... */ | |
AT91C_BASE_AIC->AIC_IECR = ( 1 << portUSART0_AIC_CHANNEL ); | |
/* Enable receiver and transmitter... */ | |
AT91C_BASE_US0->US_CR = US_RXEN | US_TXEN; | |
} | |
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; | |
/* 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 ) | |
{ | |
/* Place the character in the queue of characters to be transmitted. */ | |
if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS ) | |
{ | |
return pdFAIL; | |
} | |
/* Turn on the Tx interrupt so the ISR will remove the character from the | |
queue and send it. This does not need to be in a critical section as | |
if the interrupt has already removed the character the next interrupt | |
will simply turn off the Tx interrupt again. */ | |
AT91C_BASE_US0->US_IER = US_TXRDY; | |
return pdPASS; | |
} | |
/*-----------------------------------------------------------*/ | |
void vSerialClose( xComPortHandle xPort ) | |
{ | |
/* Not supported as not required by the demo application. */ | |
} | |
/*-----------------------------------------------------------*/ | |