atadev.c

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/*! \file atadev.c \brief IDE-ATA interface device driver. */
//*****************************************************************************
//
// File Name    : 'atadev.c'
// Title        : IDE-ATA interface device driver
// Author       : Pascal Stang
// Date         : 8/15/2004
// Revised      : 8/15/2004
// Version      : 0.1
// Target MCU   : ARMmini LPC210x
// Editor Tabs  : 4
//
// NOTE: This code is currently below version 1.0, and therefore is considered
// to be lacking in some functionality or documentation, or may not be fully
// tested.  Nonetheless, you can expect most functions to work.
//
// This code is distributed under the GNU Public License
//      which can be found at http://www.gnu.org/licenses/gpl.txt
//
//*****************************************************************************

#include "global.h"
#include "timer.h"
#include "rprintf.h"
#include "membus.h"

#include "atadev.h"

// global variables
const DevBlock_t DevBlockAta =
{
    atadevInit,
    atadevReset,
    atadevReadReg,
    atadevWriteReg,
    atadevReadData,
    atadevWriteData
};

// functions

// initialize the interface
int atadevInit(void)
{
    membusInit();
    return 0;
}

// reset the interface
int atadevReset(void)
{
    return 0;
}

// read a value from an IDE-ATA device register
u08 atadevReadReg(u16 reg)
{
    if(reg < 0x08)
        return membusRead(ATA_REG_BASE_CS1+reg);
    else
        return membusRead(ATA_REG_BASE_CS2+reg-0x08);
}

// write a value to an IDE-ATA device register
void atadevWriteReg(u16 reg, u08 data)
{
    if(reg < 0x08)
        membusWrite(ATA_REG_BASE_CS1+reg, data);
    else
        membusWrite(ATA_REG_BASE_CS2+reg-0x08, data);
}

// read data from IDE-ATA device
int atadevReadData(u08 *buffer, int numBytes)
{
    register unsigned int i;

    uint16_t* buf = (uint16_t*)buffer;

    // read data from drive
    for (i=0; i<(numBytes/16); i++)
    {
        // optimize by reading 16 bytes in-line before looping
        *buf++ = membusRead(ATA_REG_BASE_CS1+ATA_REG_DATA);
        *buf++ = membusRead(ATA_REG_BASE_CS1+ATA_REG_DATA);
        *buf++ = membusRead(ATA_REG_BASE_CS1+ATA_REG_DATA);
        *buf++ = membusRead(ATA_REG_BASE_CS1+ATA_REG_DATA);
        *buf++ = membusRead(ATA_REG_BASE_CS1+ATA_REG_DATA);
        *buf++ = membusRead(ATA_REG_BASE_CS1+ATA_REG_DATA);
        *buf++ = membusRead(ATA_REG_BASE_CS1+ATA_REG_DATA);
        *buf++ = membusRead(ATA_REG_BASE_CS1+ATA_REG_DATA);
    }
    return numBytes;
}

// write data to IDE-ATA device
int atadevWriteData(u08 *buffer, int numBytes)
{
    register unsigned int i;

    uint16_t* buf = (uint16_t*)buffer;

    // write data to drive
    for (i=0; i<(numBytes/16); i++)     
    {
        // optimize by writing 16 bytes in-line before looping
        membusWrite(ATA_REG_BASE_CS1+ATA_REG_DATA, *buf++);
        membusWrite(ATA_REG_BASE_CS1+ATA_REG_DATA, *buf++);
        membusWrite(ATA_REG_BASE_CS1+ATA_REG_DATA, *buf++);
        membusWrite(ATA_REG_BASE_CS1+ATA_REG_DATA, *buf++);
        membusWrite(ATA_REG_BASE_CS1+ATA_REG_DATA, *buf++);
        membusWrite(ATA_REG_BASE_CS1+ATA_REG_DATA, *buf++);
        membusWrite(ATA_REG_BASE_CS1+ATA_REG_DATA, *buf++);
        membusWrite(ATA_REG_BASE_CS1+ATA_REG_DATA, *buf++);
    }
    return numBytes;
}

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