ide_access.c

万龙开发板的原理图和pcb图

#include "ide_include.h"

IDE_Internal_t IDE_Internal;


//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
UI8 IDE_SectorByte(UI16 sublocation)
{
UI8 data=0;    
#ifdef DEBUG_LV0_ON
if(sublocation > (HDD_SECTOR_SIZE-1))DEBUG_OUT("\r\ndy's debug:in <IDE_SectorByte()>:sublocation > 511\r\n");
#endif

      
    data=IDE_Internal.currentsector[sublocation];	  // Read Data from specified pos
	return (data);
}

//-----------------------------------------------------------------------------
// IDE_SectorWord: Function is used to retrieve a word from the 'currentsector'
// array. The value passed in must be between 0 - 510.
//
// Parameters: Word location within currentsector
//
// Returns: Word of data requested from currentsector
//-----------------------------------------------------------------------------
UI16 IDE_SectorWord(UI16 sublocation) // Return Word at position specified
{

#ifdef DEBUG_LV0_ON
	if(sublocation > (HDD_SECTOR_SIZE-2))
	{
	DEBUG_OUT("\r\ndy's debug:in <IDE_SectorWord()>:sublocation > 510\r\n");
	s3c44b0x_SysHalt();	
	}
#endif
	
	return (IDE_Internal.currentsector[sublocation]+(IDE_Internal.currentsector[sublocation+1]<<8));
	 	// Return value
//不用指针取数是因为可能给出的索引值并不能保证字对齐	 	
}

//-----------------------------------------------------------------------------
// IDE_SectorUI32: Function is used to retrieve a 32 bit value from the 
// 'currentsector' array. The value passed in must be between 0 - 511.
//
// Parameters: Word offset within current sector
//
// Returns: 32 bit unsigned data as requested
//
// Functions Used: None
//
//-----------------------------------------------------------------------------
UI32 IDE_SectorUI32(UI16 sublocation) // Return UI32 at position specified
{
#ifdef DEBUG_LV0_ON
	if(sublocation > (HDD_SECTOR_SIZE-4))
	{
	DEBUG_OUT("\r\ndy's debug:in <IDE_SectorUI32()>:sublocation > 508\r\n");
	s3c44b0x_SysHalt();	
	}
#endif
	 return (IDE_Internal.currentsector[sublocation] + (IDE_Internal.currentsector[sublocation+1]<<8) + (IDE_Internal.currentsector[sublocation+2]<<16) + (IDE_Internal.currentsector[sublocation+3]<<24));
	 
	 	// Return value
//不用指针取数是因为可能给出的索引值并不能保证长字对齐	 	
}

//-----------------------------------------------------------------------------
// IDE_BufferSector: This function recieves the LBA address of a sector and reads into
// an array of 512 bytes (1 sector) called 'currentsector'.
//
// Parameters: 32bit Unsigned Logical Block Address
//
// Returns: An integer error code: 1 means read successfull, 0 means read fail.
//
// Functions Used: WriteReg, CheckforError, ReadErrors, Wait_DRQ, Set_Address, 
// 			 	   DataInputSetup, s3c44b0x_Printf
//
//-----------------------------------------------------------------------------
int IDE_BufferSector(UI32 LBALocation)
{
    UI16    i;
	
	if (LBALocation>=IDE_Internal.maxLBA) 
	   {
	   s3c44b0x_Printf("\r\nIDE_BufferSector: Out of Range Disc Read of 0x%lx", LBALocation);
	   // Return failure
	   return 0;
	   }
	
	if (IDE_Internal.SectorCurrentlyLoaded!=LBALocation) // Dont reload if already loaded
	{
	IDE_Internal.SectorCurrentlyLoaded=LBALocation; // update current sector loaded

    WriteReg(SECTOR_COUNT, 1); 		   	 	   // 1 Sector to be read only
    
    WriteReg(HEAD_DEVICE_PIO, (((LBALocation >> 24) & 0xFF) | 0xE0));
    WriteReg(CYLINDERHIGH, ((LBALocation >> 16) & 0xFF));
    WriteReg(CYLINDERLOW,((LBALocation >> 8) & 0xFF));
    WriteReg(START_SECTOR,(LBALocation & 0xFF));


//===========================
//	if (CheckforError()) ReadErrors(); 		   // Were there any Errors ?			   
//	Wait_DRQ();			 // Wait till Data is available in IDE buffer
//上面的部分被下面的替换了，这样便可以工作
//===========================

//===========================
	WriteReg(COMMAND, READ);    			   // Read sector

	Wait_DRQBusy();
	//源自陈猛
//===========================
	
						 // Reading Status Register reset INT too
    	#ifdef DEBUG_LV0_ON
	DEBUG_OUT("\n\rdy's debug:in<IDE_BufferSector> Exit <Wait_DRQ>");
	#endif


	for(i=0; i <HDD_SECTOR_SIZE; i=i+2)
	{
		*((UI16*)(&(IDE_Internal.currentsector[i]))) = ReadWord(DATA);
	}
	
	if (CheckforError()) ReadErrors(); // Were there any Errors ?
	}
	
	// Return Success
	return 1;
}

//-----------------------------------------------------------------------------
// IDE_PowerOn: Function set port directions, default values of output pins
// and performs a Hard Reset
//-----------------------------------------------------------------------------
void IDE_Reset(void)
{

	  // Set to defualt value
	  IDE_Internal.SectorCurrentlyLoaded = 0xffffffff;
}

//-----------------------------------------------------------------------------
// InitDrive: Drive Initialisation routine, required before you use the drive 
// for reading or writting to the actual media. 
//-----------------------------------------------------------------------------
void IDE_InitDrive(void)
{
	
/*
Initialize device parameters
OPCODE
- 91h
INPUTS
- The Sector Count register specifies the number of logical sectors per logical track, and the
Device/Head register which specifies the number of logical heads minus 1.
ERROR OUTPUTS
- Aborted Command if the device does not support the requested CHS translation.
DESCRIPTION 
- This command enables the host to set the number of logical sectors per track and the
number of logical heads minus 1, per logical cylinder for the current CHS translation mode.
Upon receipt of the command, the device sets the BSY bit, saves the parameters, clears the BSY bit, and
generates an interrupt.
A device shall support the CHS translation described in words 1, 3 and 6 of the IDENTIFY DEVICE
information. Support of other CHS translations is optional.
If the requested CHS translation is not supported, the device shall set the Error bit in the Status register and
set the Aborted Command bit in the Error register before clearing the BSY bit in the Status register.
If the requested CHS translation is not supported, the device shall fail all media access commands with an ID
Not Found error until a valid CHS translation is established.
*/	


 	 WriteReg(SECTOR_COUNT, 0x3F);
	 WriteReg(HEAD_DEVICE_PIO, 0xAF);
	 WriteReg(COMMAND, 0x91);  		 		// This command is essential
	 // Select LBA, Master Drive and Head 0
	 WriteReg(HEAD_DEVICE_PIO, 0xE0); 

/*
#ifdef DEBUG_LV0_ON
	DEBUG_OUT("\n\rdy's debug:Enter <WriteReg(HEAD_DEVICE_PIO,(0xA0+(0xe0&0x10)));>");		
#endif
	WriteReg(HEAD_DEVICE_PIO,(0xA0+(0xe0&0x10)));
#ifdef DEBUG_LV0_ON
	DEBUG_OUT("\n\rdy's debug:Exit <WriteReg(HEAD_DEVICE_PIO,(0xA0+(0xe0&0x10)));>");		
#endif
*/
	 // Read Max LBA Read address
	 IDE_Internal.maxLBA = Fetch_ID_Max_LBA(0);
}