/*
    FreeRTOS V7.3.0 - Copyright (C) 2012 Real Time Engineers Ltd.

    FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME.  PLEASE VISIT 
    http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.

    ***************************************************************************
     *                                                                       *
     *    FreeRTOS tutorial books are available in pdf and paperback.        *
     *    Complete, revised, and edited pdf reference manuals are also       *
     *    available.                                                         *
     *                                                                       *
     *    Purchasing FreeRTOS documentation will not only help you, by       *
     *    ensuring you get running as quickly as possible and with an        *
     *    in-depth knowledge of how to use FreeRTOS, it will also help       *
     *    the FreeRTOS project to continue with its mission of providing     *
     *    professional grade, cross platform, de facto standard solutions    *
     *    for microcontrollers - completely free of charge!                  *
     *                                                                       *
     *    >>> See http://www.FreeRTOS.org/Documentation for details. <<<     *
     *                                                                       *
     *    Thank you for using FreeRTOS, and thank you for your support!      *
     *                                                                       *
    ***************************************************************************


    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.  See the GNU General Public License for
    more details. You should have received a copy of the GNU General Public
    License and the FreeRTOS license exception along with FreeRTOS; if not it
    can be viewed here: http://www.freertos.org/a00114.html and also obtained
    by writing to Richard Barry, contact details for whom are available on the
    FreeRTOS WEB site.

    1 tab == 4 spaces!
    
    ***************************************************************************
     *                                                                       *
     *    Having a problem?  Start by reading the FAQ "My application does   *
     *    not run, what could be wrong?"                                     *
     *                                                                       *
     *    http://www.FreeRTOS.org/FAQHelp.html                               *
     *                                                                       *
    ***************************************************************************

    
    http://www.FreeRTOS.org - Documentation, training, latest versions, license 
    and contact details.  
    
    http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
    including FreeRTOS+Trace - an indispensable productivity tool.

    Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell 
    the code with commercial support, indemnification, and middleware, under 
    the OpenRTOS brand: http://www.OpenRTOS.com.  High Integrity Systems also
    provide a safety engineered and independently SIL3 certified version under 
    the SafeRTOS brand: http://www.SafeRTOS.com.
*/

/*
	BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER FOR UART0.
*/

/* Scheduler includes. */
#include "FreeRTOS.h"
#include "queue.h"
#include "semphr.h"

/* Library includes. */
#include "stm32f10x_lib.h"

/* Demo application includes. */
#include "serial.h"
/*-----------------------------------------------------------*/

/* Misc defines. */
#define serINVALID_QUEUE				( ( xQueueHandle ) 0 )
#define serNO_BLOCK						( ( portTickType ) 0 )
#define serTX_BLOCK_TIME				( 40 / portTICK_RATE_MS )

/*-----------------------------------------------------------*/

/* The queue used to hold received characters. */
static xQueueHandle xRxedChars;
static xQueueHandle xCharsForTx;

/*-----------------------------------------------------------*/

/* UART interrupt handler. */
void vUARTInterruptHandler( void );

/*-----------------------------------------------------------*/

/*
 * See the serial2.h header file.
 */
xComPortHandle xSerialPortInitMinimal( unsigned portLONG ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
{
xComPortHandle xReturn;
USART_InitTypeDef USART_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
GPIO_InitTypeDef GPIO_InitStructure;

	/* Create the queues used to hold Rx/Tx characters. */
	xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
	xCharsForTx = xQueueCreate( uxQueueLength + 1, ( unsigned portBASE_TYPE ) sizeof( signed portCHAR ) );
	
	/* If the queue/semaphore was created correctly then setup the serial port
	hardware. */
	if( ( xRxedChars != serINVALID_QUEUE ) && ( xCharsForTx != serINVALID_QUEUE ) )
	{
		/* Enable USART1 clock */
		RCC_APB2PeriphClockCmd( RCC_APB2Periph_USART1 | RCC_APB2Periph_GPIOA, ENABLE );	

		/* Configure USART1 Rx (PA10) as input floating */
		GPIO_InitStructure.GPIO_Pin = GPIO_Pin_10;
		GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
		GPIO_Init( GPIOA, &GPIO_InitStructure );
		
		/* Configure USART1 Tx (PA9) as alternate function push-pull */
		GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
		GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
		GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
		GPIO_Init( GPIOA, &GPIO_InitStructure );

		USART_InitStructure.USART_BaudRate = ulWantedBaud;
		USART_InitStructure.USART_WordLength = USART_WordLength_8b;
		USART_InitStructure.USART_StopBits = USART_StopBits_1;
		USART_InitStructure.USART_Parity = USART_Parity_No ;
		USART_InitStructure.USART_HardwareFlowControl = USART_HardwareFlowControl_None;
		USART_InitStructure.USART_Mode = USART_Mode_Rx | USART_Mode_Tx;
		USART_InitStructure.USART_Clock = USART_Clock_Disable;
		USART_InitStructure.USART_CPOL = USART_CPOL_Low;
		USART_InitStructure.USART_CPHA = USART_CPHA_2Edge;
		USART_InitStructure.USART_LastBit = USART_LastBit_Disable;
		
		USART_Init( USART1, &USART_InitStructure );
		
		USART_ITConfig( USART1, USART_IT_RXNE, ENABLE );
		
		NVIC_InitStructure.NVIC_IRQChannel = USART1_IRQChannel;
		NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = configLIBRARY_KERNEL_INTERRUPT_PRIORITY;
		NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
		NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
		NVIC_Init( &NVIC_InitStructure );
		
		USART_Cmd( USART1, ENABLE );		
	}
	else
	{
		xReturn = ( xComPortHandle ) 0;
	}

	/* This demo file only supports a single port but we have to return
	something to comply with the standard demo header file. */
	return xReturn;
}
/*-----------------------------------------------------------*/

signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed portCHAR *pcRxedChar, portTickType xBlockTime )
{
	/* The port handle is not required as this driver only supports one port. */
	( 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;

	/* A couple of parameters that this port does not use. */
	( void ) usStringLength;
	( void ) pxPort;

	/* 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 UART1. */
	( 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 )
{
signed portBASE_TYPE xReturn;

	if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) == pdPASS )
	{
		xReturn = pdPASS;
		USART_ITConfig( USART1, USART_IT_TXE, ENABLE );
	}
	else
	{
		xReturn = pdFAIL;
	}

	return xReturn;
}
/*-----------------------------------------------------------*/

void vSerialClose( xComPortHandle xPort )
{
	/* Not supported as not required by the demo application. */
}
/*-----------------------------------------------------------*/

void vUARTInterruptHandler( void )
{
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
portCHAR cChar;

	if( USART_GetITStatus( USART1, USART_IT_TXE ) == SET )
	{
		/* The interrupt was caused by the THR becoming empty.  Are there any
		more characters to transmit? */
		if( xQueueReceiveFromISR( xCharsForTx, &cChar, &xHigherPriorityTaskWoken ) == pdTRUE )
		{
			/* A character was retrieved from the queue so can be sent to the
			THR now. */
			USART_SendData( USART1, cChar );
		}
		else
		{
			USART_ITConfig( USART1, USART_IT_TXE, DISABLE );		
		}		
	}
	
	if( USART_GetITStatus( USART1, USART_IT_RXNE ) == SET )
	{
		cChar = USART_ReceiveData( USART1 );
		xQueueSendFromISR( xRxedChars, &cChar, &xHigherPriorityTaskWoken );
	}	
	
	portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
}