/* ----------------------------------------------------------------------------
 *         ATMEL Microcontroller Software Support
 * ----------------------------------------------------------------------------
 * Copyright (c) 2009, Atmel Corporation
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the disclaimer below.
 *
 * Atmel's name may not be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
 * DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * ----------------------------------------------------------------------------
 */

/**
 * \file
 *
 * Implementation of ADS7843 driver.
 *
 */

/*----------------------------------------------------------------------------
 *        Headers
 *----------------------------------------------------------------------------*/

#include "board.h"

/*----------------------------------------------------------------------------
 *        Definitions
 *----------------------------------------------------------------------------*/

#define ADS_CTRL_PD0              (1 << 0)        /* PD0 */
#define ADS_CTRL_PD1              (1 << 1)        /* PD1 */
#define ADS_CTRL_DFR              (1 << 2)        /* SER/DFR */
#define ADS_CTRL_EIGHT_BITS_MOD   (1 << 3)        /* Mode */
#define ADS_CTRL_START            (1 << 7)        /* Start Bit */
#define ADS_CTRL_SWITCH_SHIFT     4               /* Address setting */

/* Get X position command */
#define CMD_Y_POSITION ((1 << ADS_CTRL_SWITCH_SHIFT) | ADS_CTRL_START | ADS_CTRL_PD0 | ADS_CTRL_PD1)
/* Get Y position command */
#define CMD_X_POSITION ((5 << ADS_CTRL_SWITCH_SHIFT) | ADS_CTRL_START | ADS_CTRL_PD0 | ADS_CTRL_PD1)

/* Enable penIRQ */
#define CMD_ENABLE_PENIRQ  ((1 << ADS_CTRL_SWITCH_SHIFT) | ADS_CTRL_START)


#define ADS7843_TIMEOUT        5000000

#define DELAY_BEFORE_SPCK          200 /* 2us min (tCSS) <=> 200/100 000 000 = 2us */
#define DELAY_BETWEEN_CONS_COM     0xf /* 5us min (tCSH) <=> (32 * 15) / (100 000 000) = 5us */

/*----------------------------------------------------------------------------
 *        Local variables
 *----------------------------------------------------------------------------*/

/** Pins used by SPI */
static const Pin pinsSPI[]  = {BOARD_TSC_SPI_PINS, BOARD_TSC_NPCS_PIN};

/** Touch screen BUSY pin */
static const Pin pinBusy[] = {PIN_TSC_BUSY};

/*----------------------------------------------------------------------------
 *        Local functions
 *----------------------------------------------------------------------------*/

/**
 * \brief Generic function to send a command to the touchscreen controller.
 *
 * \param bCmd command to send
 *
 * \return command result
 */
static uint32_t SendCommand( uint8_t bCmd )
{
    uint32_t  uResult = 0;
    uint32_t  uTimeout = 0;

    /* (volatile declaration needed for code optimisation by compiler) */
    volatile uint8_t bufferRX[3];
    volatile uint8_t bufferTX[3];

    Pdc *pPdc = (Pdc *)SPI;
    uint32_t dStatus;

    bufferRX[0] = 0;
    bufferRX[1] = 0;
    bufferRX[2] = 0;

    bufferTX[0] = bCmd;
    bufferTX[1] = 0;
    bufferTX[2] = 0;

    /* Send Command and data through the SPI */
    pPdc->PERIPH_PTCR = PERIPH_PTCR_RXTDIS;
    pPdc->PERIPH_RPR = (uint32_t) bufferRX;
    pPdc->PERIPH_RCR = 3;

    pPdc->PERIPH_PTCR = PERIPH_PTCR_TXTDIS;
    pPdc->PERIPH_TPR = (uint32_t) bufferTX;
    pPdc->PERIPH_TCR = 3;

    pPdc->PERIPH_PTCR = PERIPH_PTCR_RXTEN;
    pPdc->PERIPH_PTCR = PERIPH_PTCR_TXTEN;

    do
    {
        dStatus = REG_SPI_SR;
        uTimeout++;
    }
    while ((( dStatus & SPI_SR_RXBUFF) != SPI_SR_RXBUFF) && (uTimeout < ADS7843_TIMEOUT));

    pPdc->PERIPH_PTCR = PERIPH_PTCR_RXTDIS;
    pPdc->PERIPH_PTCR = PERIPH_PTCR_TXTDIS;

    uResult = (uint32_t)bufferRX[1] << 8;
    uResult |= (uint32_t)bufferRX[2];
    uResult = uResult >> 4;

    return uResult;
}

/*----------------------------------------------------------------------------
 *        Exported functions
 *----------------------------------------------------------------------------*/

/**
 * \brief Get position of the pen by ask the ADS controller (SPI).
 *
 * \param px_pos pointer to the horizontal position
 * \param py_pos pointer to the vertical position
 *
 */
extern void ADS7843_GetPosition( uint32_t *px_pos, uint32_t *py_pos )
{
    /* Get X position */
    *px_pos = SendCommand(CMD_X_POSITION);
    /* Get Y position */
    *py_pos = SendCommand(CMD_Y_POSITION);
    /* Switch to full power mode */
    SendCommand(CMD_ENABLE_PENIRQ);
}

/**
 * \brief Initialization of the SPI for communication with ADS7843 component.
 */
extern void ADS7843_Initialize( void )
{
    volatile uint32_t uDummy;

    /* Configure pins */
    PIO_Configure(pinsSPI, PIO_LISTSIZE(pinsSPI));

    PIO_Configure(pinBusy, PIO_LISTSIZE(pinBusy));

    SPI_Configure(BOARD_TSC_SPI_BASE,
                  BOARD_TSC_SPI_ID,
                  SPI_MR_MSTR | SPI_MR_MODFDIS | SPI_PCS(BOARD_TSC_NPCS) /* Value of the SPI configuration register. */
    );

    SPI_ConfigureNPCS(BOARD_TSC_SPI_BASE, BOARD_TSC_NPCS,
                      SPI_CSR_NCPHA | SPI_CSR_DLYBS(DELAY_BEFORE_SPCK) |
                      SPI_CSR_DLYBCT(DELAY_BETWEEN_CONS_COM) | SPI_CSR_SCBR(0xC8) );

    SPI_Enable(BOARD_TSC_SPI_BASE);

    for (uDummy=0; uDummy<100000; uDummy++);

    uDummy = REG_SPI_SR;
    uDummy = REG_SPI_RDR;

    SendCommand(CMD_ENABLE_PENIRQ);
}

/**
 * \brief Reset the ADS7843
 */
void ADS7843_Reset( void )
{
    /* Disable SPI */
    SPI_Disable( BOARD_TSC_SPI_BASE ) ;
}