/*
	This serial port driver is borrowed heavily from DZComm.  I have
	simplified it by removing a lot of the functionality (hardware 
	flow control, etc.).  For more details and the full version see
	http://dzcomm.sourceforge.net


	FreeRTOS.org V4.1.1 - Copyright (C) 2003-2006 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.

	***************************************************************************
	See http://www.FreeRTOS.org for documentation, latest information, license 
	and contact details.  Please ensure to read the configuration and relevant 
	port sections of the online documentation.
	***************************************************************************
*/

/*
Changes from V1.00:
	
	+ Call to the more efficient portSWITCH_CONTEXT() replaces the call to 
	  taskYIELD() in the ISR.

Changes from V1.2.0:

	+ Added vSerialPutString().

Changes from V1.2.3

	+ The function xPortInitMinimal() has been renamed to 
	  xSerialPortInitMinimal() and the function xPortInit() has been renamed
	  to xSerialPortInit().

Changes From V2.0.0

	+ Use portTickType in place of unsigned pdLONG for delay periods.
	+ cQueueReieveFromISR() used in place of xQueueReceive() in ISR.
*/


#include <stdlib.h>
#include <dos.h>
#include "FreeRTOS.h"
#include "queue.h"
#include "task.h"
#include "semphr.h"
#include "portasm.h"

#define serMAX_IRQs						( 16 )
#define serTRANSMIT_HOLD_EMPTY_INT		( 0x02 )
#define serCOM1_STANDARD_IRQ			( ( unsigned portCHAR ) 4 )
#define serCOM2_STANDARD_IRQ			( ( unsigned portCHAR ) 3 )


#define	serIMR_8259_0					( ( unsigned portCHAR ) 0x21 )
#define	serIMR_8259_1					( ( unsigned portCHAR ) 0xa1 )
#define	serISR_8259_0					( ( unsigned portCHAR ) 0x20 )
#define	serISR_8259_1					( ( unsigned portCHAR ) 0xa0 )
#define	serALL_COMS_INTERRUPTS			( ( unsigned portCHAR ) 0x0f )
#define	serALL_MODEM_CTRL_INTERRUPTS	( ( unsigned portCHAR ) 0x0f )

#define serTRANSMIT_HOLD_OFFSET					( 0 )
#define serRECEIVE_DATA_OFFSET					( 0 )
#define serBAUD_RATE_DIVISOR_LOW_OFFSET			( 0 )
#define serBAUD_RATE_DIVISOR_HIGH_OFFSET		( 1 )
#define serINTERRUPT_ENABLE_OFFSET				( 1 )
#define serINTERRUPT_ID_OFFSET					( 2 )
#define serFIFO_CTRL_OFFSET						( 2 )
#define serLINE_CTRL_OFFSET						( 3 )
#define serMODEM_CTRL_OFFSET					( 4 )
#define serLINE_STATUS_OFFSET					( 5 )
#define serMODEM_STATUS_OFFSET					( 6 )
#define serSCR_OFFSET							( 7 )

#define serMAX_BAUD			( ( unsigned portLONG ) 115200UL )

#define serNO_INTERRUPTS	( 0x00 )

#define vInterruptOn( pxPort, ucInterrupt )										\
{																				\
	unsigned portCHAR ucIn = portINPUT_BYTE( pxPort->usInterruptEnableReg );	\
	if( !( ucIn & ucInterrupt ) )												\
	{																			\
		portOUTPUT_BYTE( pxPort->usInterruptEnableReg, ucIn | ucInterrupt );	\
	}																			\
}																				
/*-----------------------------------------------------------*/

#define vInterruptOff( pxPort, ucInterrupt )									\
{																				\
	unsigned portCHAR ucIn = portINPUT_BYTE( pxPort->usInterruptEnableReg );	\
	if( ucIn & ucInterrupt )													\
	{																			\
		portOUTPUT_BYTE( pxPort->usInterruptEnableReg, ucIn & ~ucInterrupt);	\
	}																			\
}
/*-----------------------------------------------------------*/

typedef enum
{ 
	serCOM1, 
	serCOM2, 
	serCOM3, 
	serCOM4, 
	serCOM5, 
	serCOM6, 
	serCOM7, 
	serCOM8 
} eCOMPort;

typedef enum 
{ 
	serNO_PARITY, 
	serODD_PARITY, 
	serEVEN_PARITY, 
	serMARK_PARITY, 
	serSPACE_PARITY 
} eParity;

typedef enum 
{ 
	serSTOP_1, 
	serSTOP_2 
} eStopBits;

typedef enum 
{ 
	serBITS_5, 
	serBITS_6, 
	serBITS_7, 
	serBITS_8 
} eDataBits;

typedef enum 
{ 
	ser50,		
	ser75,		
	ser110,		
	ser134,		
	ser150,    
	ser200,
	ser300,		
	ser600,		
	ser1200,	
	ser1800,	
	ser2400,   
	ser4800,
	ser9600,		
	ser19200,	
	ser38400,	
	ser57600,	
	ser115200
} eBaud;

/* This *MUST* match the order in the eBaud definition. */
unsigned portLONG ulBaudFromEnum[] = 
{ 
	( unsigned portLONG ) 50, 
	( unsigned portLONG ) 75, 
	( unsigned portLONG ) 110, 
	( unsigned portLONG ) 134, 
	( unsigned portLONG ) 150,	
	( unsigned portLONG ) 200, 
	( unsigned portLONG ) 300, 
	( unsigned portLONG ) 600, 
	( unsigned portLONG ) 1200, 
	( unsigned portLONG ) 1800, 
	( unsigned portLONG ) 2400,   
	( unsigned portLONG ) 4800,   
	( unsigned portLONG ) 9600,  
	( unsigned portLONG ) 19200,  
	( unsigned portLONG ) 38400UL,
	( unsigned portLONG ) 57600UL,
	( unsigned portLONG ) 115200UL
};

typedef struct xCOM_PORT
{ 
	unsigned portSHORT sPort;   /* comm port address eg. 0x3f8    */
	unsigned portCHAR ucIRQ;    /* comm IRQ eg. 3                 */

	/* Next two fields used for setting up the IRQ routine and
	* (un)masking the interrupt in certain circumstances.
	*/
	unsigned portSHORT usIRQVector;
	unsigned portCHAR ucInterruptEnableMast;

	/* Read/Write buffers. */
	xQueueHandle xRxedChars; 
	xQueueHandle xCharsForTx;

	/* This lot are set up to minimise CPU time where accessing the comm
	* port's registers.
	*/
	unsigned portSHORT usTransmitHoldReg; 
	unsigned portSHORT usReceiveDataRegister;
	unsigned portSHORT usBaudRateDivisorLow; 
	unsigned portSHORT usBaudRateDivisorHigh;
	unsigned portSHORT usInterruptEnableReg;
	unsigned portSHORT usInterruptIDReg;
	unsigned portSHORT usFIFOCtrlReg;
	unsigned portSHORT usLineCtrlReg;
	unsigned portSHORT usModemCtrlReg;
	unsigned portSHORT usLineStatusReg;
	unsigned portSHORT usModemStatusReg;
	unsigned portSHORT usSCRReg;
	unsigned portSHORT us8259InterruptServiceReg;
	unsigned portSHORT us8259InterruptMaskReg;

	/* This semaphore does nothing useful except test a feature of the
	scheduler. */
	xSemaphoreHandle xTestSem;

} xComPort;

typedef xComPort *xComPortHandle;

/* A xComPort structure can be associated with each IRQ.  Initially none
are create/installed. */
xComPort *xPortStatus[ serMAX_IRQs ] = { NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL };

/*-----------------------------------------------------------*/

/* These prototypes are repeated here so we don't have to include the serial header.  This allows
the xComPortHandle structure details to be private to this file. */
xComPortHandle xSerialPortInit( eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits, unsigned portBASE_TYPE uxBufferLength );
portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, portCHAR *pcRxedChar, portTickType xBlockTime );
portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, portCHAR cOutChar, portTickType xBlockTime );
portBASE_TYPE xSerialWaitForSemaphore( xComPortHandle xPort );

static void prvSetupPortHardware( xComPort *pxPort, eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits );
static portSHORT sComPortISR( const xComPort * const pxPort );

/*-----------------------------------------------------------*/

/* Define an interrupt handler for each slot in the xPortStatus array. */

#define COM_IRQ_WRAPPER(N)										\
	static void __interrupt COM_IRQ##N##_WRAPPER( void )		\
	{															\
		portDISABLE_INTERRUPTS();								\
		if( sComPortISR( xPortStatus[##N##] ) )					\
		{														\
			portSWITCH_CONTEXT();								\
		}														\
	} 

COM_IRQ_WRAPPER( 0 )
COM_IRQ_WRAPPER( 1 )
COM_IRQ_WRAPPER( 2 )
COM_IRQ_WRAPPER( 3 )
COM_IRQ_WRAPPER( 4 )
COM_IRQ_WRAPPER( 5 )
COM_IRQ_WRAPPER( 6 )
COM_IRQ_WRAPPER( 7 )
COM_IRQ_WRAPPER( 8 )
COM_IRQ_WRAPPER( 9 )
COM_IRQ_WRAPPER( 10 )
COM_IRQ_WRAPPER( 11 )
COM_IRQ_WRAPPER( 12 )
COM_IRQ_WRAPPER( 13 )
COM_IRQ_WRAPPER( 14 )
COM_IRQ_WRAPPER( 15 )

static pxISR xISRs[ serMAX_IRQs ] = 
{
	COM_IRQ0_WRAPPER, 
	COM_IRQ1_WRAPPER, 
	COM_IRQ2_WRAPPER, 
	COM_IRQ3_WRAPPER, 
	COM_IRQ4_WRAPPER, 
	COM_IRQ5_WRAPPER, 
	COM_IRQ6_WRAPPER, 
	COM_IRQ7_WRAPPER, 
	COM_IRQ8_WRAPPER, 
	COM_IRQ9_WRAPPER, 
	COM_IRQ10_WRAPPER, 
	COM_IRQ11_WRAPPER, 
	COM_IRQ12_WRAPPER, 
	COM_IRQ13_WRAPPER, 
	COM_IRQ14_WRAPPER,
	COM_IRQ15_WRAPPER
};

static pxISR xOldISRs[ serMAX_IRQs ] = { NULL };

/*-----------------------------------------------------------*/


xComPortHandle xSerialPortInit( eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits, unsigned portBASE_TYPE uxBufferLength )
{
xComPort *pxPort;

	/* Create a structure to handle this port. */
	pxPort = ( xComPort * ) pvPortMalloc( sizeof( xComPort ) );
	
	if( pxPort != NULL )
	{
		/* Create the queues used by the comtest task. */
		pxPort->xRxedChars = xQueueCreate( uxBufferLength, ( unsigned portBASE_TYPE ) sizeof( portCHAR ) );
		pxPort->xCharsForTx = xQueueCreate( uxBufferLength, ( unsigned portBASE_TYPE ) sizeof( portCHAR ) );

		/* Create the test semaphore.  This does nothing useful except test a feature of the scheduler. */
		vSemaphoreCreateBinary( pxPort->xTestSem );

		prvSetupPortHardware( pxPort, ePort, eWantedBaud, eWantedParity, eWantedDataBits, eWantedStopBits );

		return pxPort;
	}

	return NULL;
}
/*-----------------------------------------------------------*/

static void prvSetupPortHardware( xComPort *pxPort, eCOMPort ePort, eBaud eWantedBaud, eParity eWantedParity, eDataBits eWantedDataBits, eStopBits eWantedStopBits )
{
portSHORT sIn;