/* | |
FreeRTOS.org V5.3.0 - Copyright (C) 2003-2009 Richard Barry. | |
This file is part of the FreeRTOS.org distribution. | |
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under the terms of the GNU General Public License (version 2) as published | |
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*************************************************************************** | |
* * | |
* Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation * | |
* * | |
* This is a concise, step by step, 'hands on' guide that describes both * | |
* general multitasking concepts and FreeRTOS specifics. It presents and * | |
* explains numerous examples that are written using the FreeRTOS API. * | |
* Full source code for all the examples is provided in an accompanying * | |
* .zip file. * | |
* * | |
*************************************************************************** | |
1 tab == 4 spaces! | |
Please ensure to read the configuration and relevant port sections of the | |
online documentation. | |
http://www.FreeRTOS.org - Documentation, latest information, license and | |
contact details. | |
http://www.SafeRTOS.com - A version that is certified for use in safety | |
critical systems. | |
http://www.OpenRTOS.com - Commercial support, development, porting, | |
licensing and training services. | |
*/ | |
/* Scheduler includes. */ | |
#include "FreeRTOS.h" | |
#include "task.h" | |
#include "queue.h" | |
/* Demo app includes. */ | |
#include "USBSample.h" | |
#define usbINT_CLEAR_MASK (AT91C_UDP_TXCOMP | AT91C_UDP_STALLSENT | AT91C_UDP_RXSETUP | AT91C_UDP_RX_DATA_BK0 | AT91C_UDP_RX_DATA_BK1 ) | |
#define usbCSR_CLEAR_BIT( pulValueNow, ulBit ) \ | |
{ \ | |
/* Set TXCOMP, RX_DATA_BK0, RXSETUP, */ \ | |
/* STALLSENT and RX_DATA_BK1 to 1 so the */ \ | |
/* write has no effect. */ \ | |
( * ( ( unsigned portLONG * ) pulValueNow ) ) |= ( unsigned portLONG ) 0x4f; \ | |
\ | |
/* Clear the FORCE_STALL and TXPKTRDY bits */ \ | |
/* so the write has no effect. */ \ | |
( * ( ( unsigned portLONG * ) pulValueNow ) ) &= ( unsigned portLONG ) 0xffffffcf; \ | |
\ | |
/* Clear whichever bit we want clear. */ \ | |
( * ( ( unsigned portLONG * ) pulValueNow ) ) &= ( ~ulBit ); \ | |
} | |
/*-----------------------------------------------------------*/ | |
/* | |
* ISR entry point. | |
*/ | |
void vUSB_ISR_Wrapper( void ) __attribute__((naked)); | |
/* | |
* Actual ISR handler. This must be separate from the entry point as the stack | |
* is used. | |
*/ | |
void vUSB_ISR_Handler( void ); | |
/*-----------------------------------------------------------*/ | |
/* Array in which the USB interrupt status is passed between the ISR and task. */ | |
static xISRStatus xISRMessages[ usbQUEUE_LENGTH + 1 ]; | |
/* Queue used to pass messages between the ISR and the task. */ | |
extern xQueueHandle xUSBInterruptQueue; | |
/*-----------------------------------------------------------*/ | |
void vUSB_ISR_Handler( void ) | |
{ | |
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE; | |
static volatile unsigned portLONG ulNextMessage = 0; | |
xISRStatus *pxMessage; | |
unsigned portLONG ulTemp, ulRxBytes; | |
/* To reduce the amount of time spent in this interrupt it would be | |
possible to defer the majority of this processing to an 'interrupt task', | |
that is a task that runs at a higher priority than any of the application | |
tasks. */ | |
/* Take the next message from the queue. Note that usbQUEUE_LENGTH *must* | |
be all 1's, as in 0x01, 0x03, 0x07, etc. */ | |
pxMessage = &( xISRMessages[ ( ulNextMessage & usbQUEUE_LENGTH ) ] ); | |
ulNextMessage++; | |
/* Take a snapshot of the current USB state for processing at the task | |
level. */ | |
pxMessage->ulISR = AT91C_BASE_UDP->UDP_ISR; | |
pxMessage->ulCSR0 = AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ]; | |
/* Clear the interrupts from the ICR register. The bus end interrupt is | |
cleared separately as it does not appear in the mask register. */ | |
AT91C_BASE_UDP->UDP_ICR = AT91C_BASE_UDP->UDP_IMR | AT91C_UDP_ENDBUSRES; | |
/* If there are bytes in the FIFO then we have to retrieve them here. | |
Ideally this would be done at the task level. However we need to clear the | |
RXSETUP interrupt before leaving the ISR, and this may cause the data in | |
the FIFO to be overwritten. Also the DIR bit has to be changed before the | |
RXSETUP bit is cleared (as per the SAM7 manual). */ | |
ulTemp = pxMessage->ulCSR0; | |
/* Are there any bytes in the FIFO? */ | |
ulRxBytes = ulTemp >> 16; | |
ulRxBytes &= usbRX_COUNT_MASK; | |
/* With this minimal implementation we are only interested in receiving | |
setup bytes on the control end point. */ | |
if( ( ulRxBytes > 0 ) && ( ulTemp & AT91C_UDP_RXSETUP ) ) | |
{ | |
/* Take off 1 for a zero based index. */ | |
while( ulRxBytes > 0 ) | |
{ | |
ulRxBytes--; | |
pxMessage->ucFifoData[ ulRxBytes ] = AT91C_BASE_UDP->UDP_FDR[ usbEND_POINT_0 ]; | |
} | |
/* The direction must be changed first. */ | |
usbCSR_SET_BIT( &ulTemp, ( AT91C_UDP_DIR ) ); | |
AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ] = ulTemp; | |
} | |
/* Must write zero's to TXCOMP, STALLSENT, RXSETUP, and the RX DATA | |
registers to clear the interrupts in the CSR register. */ | |
usbCSR_CLEAR_BIT( &ulTemp, usbINT_CLEAR_MASK ); | |
AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ] = ulTemp; | |
/* Also clear the interrupts in the CSR1 register. */ | |
ulTemp = AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_1 ]; | |
usbCSR_CLEAR_BIT( &ulTemp, usbINT_CLEAR_MASK ); | |
AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_1 ] = ulTemp; | |
/* The message now contains the entire state and optional data from | |
the USB interrupt. This can now be posted on the Rx queue ready for | |
processing at the task level. */ | |
xQueueSendFromISR( xUSBInterruptQueue, &pxMessage, &xHigherPriorityTaskWoken ); | |
/* We may want to switch to the USB task, if this message has made | |
it the highest priority task that is ready to execute. */ | |
if( xHigherPriorityTaskWoken ) | |
{ | |
portYIELD_FROM_ISR(); | |
} | |
/* Clear the AIC ready for the next interrupt. */ | |
AT91C_BASE_AIC->AIC_EOICR = 0; | |
} | |
/*-----------------------------------------------------------*/ | |
void vUSB_ISR_Wrapper( void ) | |
{ | |
/* Save the context of the interrupted task. */ | |
portSAVE_CONTEXT(); | |
/* Call the handler itself. This must be a separate function as it uses | |
the stack. */ | |
vUSB_ISR_Handler(); | |
/* Restore the context of the task that is going to | |
execute next. This might not be the same as the originally | |
interrupted task.*/ | |
portRESTORE_CONTEXT(); | |
} |