/*
    FreeRTOS V8.2.0rc1 - Copyright (C) 2014 Real Time Engineers Ltd.
    All rights reserved

    VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

    This file is part of the FreeRTOS distribution.

    FreeRTOS is free software; you can redistribute it and/or modify it under
    the terms of the GNU General Public License (version 2) as published by the
    Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.

    >>!   NOTE: The modification to the GPL is included to allow you to     !<<
    >>!   distribute a combined work that includes FreeRTOS without being   !<<
    >>!   obliged to provide the source code for proprietary components     !<<
    >>!   outside of the FreeRTOS kernel.                                   !<<

    FreeRTOS 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.  Full license text is available on the following
    link: http://www.freertos.org/a00114.html

    1 tab == 4 spaces!

    ***************************************************************************
     *                                                                       *
     *    Having a problem?  Start by reading the FAQ "My application does   *
     *    not run, what could be wrong?".  Have you defined configASSERT()?  *
     *                                                                       *
     *    http://www.FreeRTOS.org/FAQHelp.html                               *
     *                                                                       *
    ***************************************************************************

    ***************************************************************************
     *                                                                       *
     *    FreeRTOS provides completely free yet professionally developed,    *
     *    robust, strictly quality controlled, supported, and cross          *
     *    platform software that is more than just the market leader, it     *
     *    is the industry's de facto standard.                               *
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     *    Help yourself get started quickly while simultaneously helping     *
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     *    tutorial book, reference manual, or both:                          *
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     *                                                                       *
    ***************************************************************************

    ***************************************************************************
     *                                                                       *
     *   Investing in training allows your team to be as productive as       *
     *   possible as early as possible, lowering your overall development    *
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     *   earlier than would otherwise be possible.  Richard Barry is both    *
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     *   from Richard ensures your team will gain directly from his in-depth *
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     *   Engineers Ltd to enquire about the FreeRTOS Masterclass, presented  *
     *   by Richard Barry:  http://www.FreeRTOS.org/contact
     *                                                                       *
    ***************************************************************************

    ***************************************************************************
     *                                                                       *
     *    You are receiving this top quality software for free.  Please play *
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     *    http://www.FreeRTOS.org/support                                    *
     *                                                                       *
     *    Thank you!                                                         *
     *                                                                       *
    ***************************************************************************

    http://www.FreeRTOS.org - Documentation, books, training, latest versions,
    license and Real Time Engineers Ltd. contact details.

    http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
    including FreeRTOS+Trace - an indispensable productivity tool, a DOS
    compatible FAT file system, and our tiny thread aware UDP/IP stack.

    http://www.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate.
    Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS.

    http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
    Integrity Systems ltd. to sell under the OpenRTOS brand.  Low cost OpenRTOS
    licenses offer ticketed support, indemnification and commercial middleware.

    http://www.SafeRTOS.com - High Integrity Systems also provide a safety
    engineered and independently SIL3 certified version for use in safety and
    mission critical applications that require provable dependability.

    1 tab == 4 spaces!
*/


/* 
  BASIC INTERRUPT DRIVEN DRIVER FOR USB. 

  This file contains all the usb components that must be compiled
  to ARM mode.  The components that can be compiled to either ARM or THUMB
  mode are contained in USB-CDC.c.

*/

/* Scheduler includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"

/* Demo application includes. */
#include "Board.h"
#include "usb.h"
#include "USB-CDC.h"

#define usbINT_CLEAR_MASK	(AT91C_UDP_TXCOMP | AT91C_UDP_STALLSENT | AT91C_UDP_RXSETUP | AT91C_UDP_RX_DATA_BK0 | AT91C_UDP_RX_DATA_BK1 )
/*-----------------------------------------------------------*/

/* Messages and queue used to communicate between the ISR and the USB task. */
static xISRStatus xISRMessages[ usbQUEUE_LENGTH + 1 ];
extern QueueHandle_t xUSBInterruptQueue;
/*-----------------------------------------------------------*/

/* The ISR can cause a context switch so is declared naked. */
void vUSB_ISR_Wrapper( void ) __attribute__ ((naked));

/* The function that actually performs the ISR work.  This must be separate
from the wrapper function to ensure the correct stack frame gets set up. */
void vUSB_ISR_Handler( void );
/*-----------------------------------------------------------*/

void vUSB_ISR_Handler( void )
{
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
static volatile unsigned long ulNextMessage = 0;
xISRStatus *pxMessage;
unsigned long ulRxBytes;
unsigned char ucFifoIndex;

    /* Use the next message from the array. */
	pxMessage = &( xISRMessages[ ( ulNextMessage & usbQUEUE_LENGTH ) ] );
	ulNextMessage++;

    /* Save UDP ISR state for task-level processing. */
	pxMessage->ulISR = AT91C_BASE_UDP->UDP_ISR;
	pxMessage->ulCSR0 = AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ];

    /* Clear interrupts from ICR. */
	AT91C_BASE_UDP->UDP_ICR = AT91C_BASE_UDP->UDP_IMR | AT91C_UDP_ENDBUSRES;
	
    
	/* Process incoming FIFO data.  Must set DIR (if needed) and clear RXSETUP 
	before exit. */

    /* Read CSR and get incoming byte count. */
	ulRxBytes = ( pxMessage->ulCSR0 >> 16 ) & usbRX_COUNT_MASK;
	
	/* Receive control transfers on endpoint 0. */
	if( pxMessage->ulCSR0 & ( AT91C_UDP_RXSETUP | AT91C_UDP_RX_DATA_BK0 ) )
	{
		/* Save FIFO data buffer for either a SETUP or DATA stage */
		for( ucFifoIndex = 0; ucFifoIndex < ulRxBytes; ucFifoIndex++ )
		{
			pxMessage->ucFifoData[ ucFifoIndex ] = AT91C_BASE_UDP->UDP_FDR[ usbEND_POINT_0 ];
		}

		/* Set direction for data stage.  Must be done before RXSETUP is 
		cleared. */
		if( ( AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ] & AT91C_UDP_RXSETUP ) )
		{
			if( ulRxBytes && ( pxMessage->ucFifoData[ usbREQUEST_TYPE_INDEX ] & 0x80 ) )
			{
				AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ] |= AT91C_UDP_DIR;

				/* Might not be wise in an ISR! */
				while( !(AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ] & AT91C_UDP_DIR) );
			}

			/* Clear RXSETUP */
			AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ] &= ~AT91C_UDP_RXSETUP;

			/* Might not be wise in an ISR! */
			while ( AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ] & AT91C_UDP_RXSETUP );
		}
		else
		{
		   /* Clear RX_DATA_BK0 */
		   AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ] &= ~AT91C_UDP_RX_DATA_BK0;

		   /* Might not be wise in an ISR! */
		   while ( AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ] & AT91C_UDP_RX_DATA_BK0 );
		}
	}
	
	/* If we received data on endpoint 1, disable its interrupts until it is 
	processed in the main loop */
	if( AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_1 ] & ( AT91C_UDP_RX_DATA_BK0 | AT91C_UDP_RX_DATA_BK1 ) )
	{
		AT91C_BASE_UDP->UDP_IDR = AT91C_UDP_EPINT1;
	}
	
	AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_0 ] &= ~( AT91C_UDP_TXCOMP | AT91C_UDP_STALLSENT );
     
	/* Clear interrupts for the other endpoints, retain data flags for endpoint 
	1. */
	AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_1 ] &= ~( AT91C_UDP_TXCOMP | AT91C_UDP_STALLSENT | AT91C_UDP_RXSETUP );
	AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_2 ] &= ~usbINT_CLEAR_MASK;
	AT91C_BASE_UDP->UDP_CSR[ usbEND_POINT_3 ] &= ~usbINT_CLEAR_MASK;

	/* Post ISR data to queue for task-level processing */
	xQueueSendFromISR( xUSBInterruptQueue, &pxMessage, &xHigherPriorityTaskWoken );

	/* Clear AIC to complete ISR processing */
	AT91C_BASE_AIC->AIC_EOICR = 0;

	/* Do a task switch if needed */
	if( xHigherPriorityTaskWoken )
	{
		/* This call will ensure that the unblocked task will be executed
		immediately upon completion of the ISR if it has a priority higher
		than the interrupted task. */
		portYIELD_FROM_ISR();
	}
}
/*-----------------------------------------------------------*/

void vUSB_ISR_Wrapper( void )
{
	/* Save the context of the interrupted task. */
	portSAVE_CONTEXT();

	/* Call the handler to do the work.  This must be a separate
	function to ensure the stack frame is set up correctly. */
	vUSB_ISR_Handler();

	/* Restore the context of whichever task will execute next. */
	portRESTORE_CONTEXT();
}