/*********************************************************************
 *
 *                  SPI API implementation file
 *
 *********************************************************************
 * FileName:        spi_chn_open_lib.c
 * Dependencies:	Spi.h
 *
 * Processor:       PIC32
 *
 * Complier:        MPLAB C32
 *                  MPLAB IDE
 * Company:         Microchip Technology Inc..
 *
 * Software License Agreement
 *
 * The software supplied herewith by Microchip Technology Incorporated
 * (the Company) for its PIC32 Microcontroller is intended
 * and supplied to you, the Companys customer, for use solely and
 * exclusively on Microchip PIC32 Microcontroller products.
 * The software is owned by the Company and/or its supplier, and is
 * protected under applicable copyright laws. All rights are reserved.
 * Any use in violation of the foregoing restrictions may subject the
 * user to criminal sanctions under applicable laws, as well as to
 * civil liability for the breach of the terms and conditions of this
 * license.
 *
 * THIS SOFTWARE IS PROVIDED IN AN AS IS CONDITION. NO WARRANTIES,
 * WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING, BUT NOT LIMITED
 * TO, IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE APPLY TO THIS SOFTWARE. THE COMPANY SHALL NOT,
 * IN ANY CIRCUMSTANCES, BE LIABLE FOR SPECIAL, INCIDENTAL OR
 * CONSEQUENTIAL DAMAGES, FOR ANY REASON WHATSOEVER.
 *
 *
 * $Id$
 * $Name$
 *
 ********************************************************************/
#include <peripheral/spi.h>
#include <peripheral/ports.h>
#include <peripheral/int.h>

#include "_spi_io_tbl.h"
#include "_spi_map_tbl.h"


/********************
 * Channel functions.
 * Defined only if there's at least one valid SPI channel
 * *********************************/
#ifdef _SPI_DEF_CHN_


/*********************************************************************
 * Function:        void SpiChnOpen(SpiChannel chn, SpiOpenFlags oFlags, unsigned int fpbDiv)
 *
 * PreCondition:    fpbDiv	- valid value between 2 and 1024
 *
 * Input:			chn		- the channel to set
 * 					oFlags	- a SpiOpenFlags or __SPIxCONbits_t structure that sets the module behavior
 *					fpbDiv	- Fpb divisor to extract the baud rate: BR=Fpb/fpbDiv.
 *
 * Output:          None
 *
 * Side Effects:    None
 *
 * Overview:        This function initializes the SPI channel and also sets the brg register.
 * 					The SPI baudrate BR is given by: BR=Fpb/(2*(SPIBRG+1))
 * 					The input parametes fpbDiv specifies the Fpb divisor term (2*(SPIBRG+1)),
 * 					so the BRG is calculated as SPIBRG=fpbDiv/2-1.
 *
 * Note:            - The baud rate is always obtained by dividing the Fpb to an even number
 * 					between 2 and 1024.
 * 					- When selecting the number of bits per character, SPI_OPEN_MODE32 has the highest priority.
 * 					If SPI_OPEN_MODE32 is not set, then SPI_OPEN_MODE16 selects the character width.
 * 					- The SPI_OPEN_SSEN is taken into account even in master mode. If it is set the library
 * 					will properly se the SS pin as an digital output.
 ********************************************************************/
void SpiChnOpen(SpiChannel chn, SpiOpenFlags oFlags, unsigned int fpbDiv)
{
	unsigned int	dummyRd;
	fConfPorts		fPorts;
	__SPIxCONbits_t		configR;
	volatile _SpiRegMap*	pReg=_SpiMapTbl[chn];
	const _SpiIoDcpt*	pDcpt=_SpiIoTbl+chn;

	INTEnable(INT_SOURCE_SPI(chn), INT_DISABLED);	// disable the channel interrupts
	pReg->conClr=__SPIxCON_MASK_(ON_MASK);		// turn off and reset

	configR.w=oFlags|__SPIxCON_MASK_(ON_MASK);	// channel configuration. make sure we turn the channel on

	// configure the output ports

	PORTSetPinsDigitalOut(pDcpt->portSdo, pDcpt->sdoMask);
	PORTSetPinsDigitalIn(pDcpt->portSdi, pDcpt->sdiMask);

	fPorts=configR.MSTEN?PORTSetPinsDigitalOut:PORTSetPinsDigitalIn;
	(*fPorts)(pDcpt->portSck, pDcpt->sckMask);		// configure the SCK

	if(configR.FRMEN || configR.SSEN)
	{
		if(configR.FRMEN)
		{
			fPorts=configR.FRMSYNC?PORTSetPinsDigitalIn:PORTSetPinsDigitalOut;
		}
		else
		{
			fPorts=configR.MSTEN?PORTSetPinsDigitalOut:PORTSetPinsDigitalIn;
		}
		(*fPorts)(pDcpt->portSS, pDcpt->ssMask);	// configure the FrmSync/SS
	}

	INTClearFlag(INT_SOURCE_SPI(chn));		// clear the existing channel interrupt flags


	pReg->brg=(fpbDiv>>1)-1;	// set the brg
	dummyRd=pReg->buf;			// clear the receive buffer
	pReg->statClr=__SPIxSTAT_MASK_(SPIROV_MASK);	// clear overflow
	pReg->con.w=configR.w;		// set the configuration word


}

#endif	// _SPI_DEF_CHN_


