#include "common.h"
#include "SL811.H"
#include "HAL.H"

extern FLAGS bdata bFlags;
PKG usbstack;
unsigned char xdata DBUF[BUFFER_LENGTH];
pUSBDEV xdata uDev;	// Multiple USB devices attributes, Max 5 devices

//*****************************************************************************************
// SL811H variables initialization
//*****************************************************************************************
void USBReset(void)
{
	unsigned char temp;
    temp=SL811Read(CtrlReg);   
 	SL811Write(CtrlReg,temp|0x08);
	DelayMs(25);
	SL811Write(CtrlReg,temp);    
}

//*****************************************************************************************
// usbXfer:
// successful transfer = return TRUE
// fail transfer = return FALSE
//*****************************************************************************************
unsigned char usbXfer(void)
{  
	
	unsigned char xferLen, data0, data1,cmd;
	unsigned char intr,result,remainder,dataX,bufLen,addr,timeout;
	unsigned char out[8];
	//------------------------------------------------
	// Default setting for usb trasnfer
	//------------------------------------------------
	dataX=timeout=0;
	
	data0 = EP0_Buf;					// DATA0 buffer address
	data1 = data0 + (unsigned char)usbstack.wPayload;	// DATA1 buffer address
	bFlags.bits.DATA_STOP=FALSE;
	bFlags.bits.TIMEOUT_ERR=FALSE;
	//------------------------------------------------
	// Define data transfer payload
	//------------------------------------------------
	if (usbstack.wLen >= usbstack.wPayload)  		// select proper data payload
		xferLen = usbstack.wPayload;			// limit to wPayload size 
	else							// else take < payload len
		xferLen = usbstack.wLen;			//	
	
	// For IN token
	if (usbstack.pid==PID_IN)				// for current IN tokens
	{												//
		cmd = sDATA0_RD;			// FS/FS on Hub, sync to sof
	}
	// For OUT token
	else if(usbstack.pid==PID_OUT)				// for OUT tokens
	{  	
		if(xferLen)									// only when there are	
			{
			SL811BufWrite(data0,usbstack.buffer,xferLen); 	// data to transfer on USB
			}
		cmd = sDATA0_WR;						// FS/FS on Hub, sync to sof
	// implement data toggle
		bFlags.bits.bData1 = uDev.bData1[usbstack.endpoint];
        	uDev.bData1[usbstack.endpoint] = (uDev.bData1[usbstack.endpoint] ? 0 : 1); // DataToggle
		
		if(bFlags.bits.bData1)
          		cmd |= 0x40;                              // Set Data1 bit in command
	}
	//------------------------------------------------
	// For SETUP/OUT token
	//------------------------------------------------
	else											// for current SETUP/OUT tokens
	{  	
		if(xferLen)									// only when there are	
			{										// data to transfer on USB
			intr=usbstack.setup.wLength;			
			out[0]=usbstack.setup.bmRequest;
			out[1]=usbstack.setup.bRequest;
			out[2]=(unsigned char)usbstack.setup.wValue;
			out[3]=(unsigned char)(usbstack.setup.wValue>>8);
			out[4]=(unsigned char)usbstack.setup.wIndex;
			out[5]=(unsigned char)(usbstack.setup.wIndex>>8);
			out[6]=(unsigned char)usbstack.setup.wLength;
			out[7]=(unsigned char)(usbstack.setup.wLength>>8);
			SL811BufWrite(data0,out,xferLen);
			usbstack.setup.wLength=intr;
			}
		cmd = sDATA0_WR;							// FS/FS on Hub, sync to sof
	}
	//------------------------------------------------
	// For EP0's IN/OUT token data, start with DATA1
	// Control Endpoint0's status stage.
	// For data endpoint, IN/OUT data, start ????
	//------------------------------------------------
	if (usbstack.endpoint == 0 && usbstack.pid != PID_SETUP) 	// for Ep0's IN/OUT token
		cmd |= 0x40; 					// always set DATA1
	//------------------------------------------------
	// Arming of USB data transfer for the first pkt
	//------------------------------------------------
	SL811Write(EP0Status,((usbstack.endpoint&0x0F)|usbstack.pid));	// PID + EP address
	SL811Write(EP0Counter,usbstack.usbaddr);					// USB address
	SL811Write(EP0Address,data0);					// buffer address, start with "data0"
	SL811Write(EP0XferLen,xferLen);					// data transfer length
	SL811Write(IntStatus,INT_CLEAR); 				// clear interrupt status
	SL811Write(EP0Control,cmd);						// Enable ARM and USB transfer start here
	
	//------------------------------------------------
	// Main loop for completing a wLen data trasnfer
	//------------------------------------------------
	while(TRUE)
	{   
		//---------------Wait for done interrupt------------------
		while(TRUE)												// always ensure requested device is
		{														// inserted at all time, then you will
			intr = SL811Read(IntStatus);	
									// wait for interrupt to be done, and 
			if((intr & USB_RESET) || (intr & INSERT_REMOVE))	// proceed to parse result from slave 
			{													// device.
				bFlags.bits.DATA_STOP = TRUE;								// if device is removed, set DATA_STOP
				return FALSE;									// flag true, so that main loop will 
			}													// know this condition and exit gracefully
			if(intr & USB_A_DONE)								
				break;							// interrupt done !!!
		}

		SL811Write(IntStatus,INT_CLEAR); // clear interrupt status
		result 	  = SL811Read(EP0Status);						// read EP0status register
		remainder = SL811Read(EP0Counter);						// remainder value in last pkt xfer

		//-------------------------ACK----------------------------
		if (result & EP0_ACK)									// Transmission ACK
		{	

			// SETUP TOKEN
			if(usbstack.pid == PID_SETUP)								// do nothing for SETUP/OUT token 
				break;											// exit while(1) immediately

			// OUT TOKEN				
			else if(usbstack.pid == PID_OUT)
				break;

			// IN TOKEN
			else if(usbstack.pid == PID_IN)
			{													// for IN token only
				usbstack.wLen  -= (WORD)xferLen;	// update remainding wLen value
				cmd   ^= 0x40;    			// toggle DATA0/DATA1
				dataX++;				// point to next dataX

				//------------------------------------------------	
				// If host requested for more data than the slave 
				// have, and if the slave's data len is a multiple
				// of its endpoint payload size/last xferLen. Do 
				// not overwrite data in previous buffer.
				//------------------------------------------------	
				if(remainder==xferLen)			// empty data detected
					bufLen = 0;			// do not overwriten previous data
				else					// reset bufLen to zero
					bufLen = xferLen;		// update previous buffer length
				
				//------------------------------------------------	
				// Arm for next data transfer when requested data 
				// length have not reach zero, i.e. wLen!=0, and
				// last xferlen of data was completed, i.e.
				// remainder is equal to zero, not a short pkt
				//------------------------------------------------	
				if(!remainder && usbstack.wLen)							// remainder==0 when last xferLen
				{												// was all completed or wLen!=0
					addr    = (dataX & 1) ? data1:data0; 		// select next address for data
					xferLen = (BYTE)(usbstack.wLen>=usbstack.wPayload) ? usbstack.wPayload:usbstack.wLen;	// get data length required
								
					cmd |= 0x20;							// always sync SOF when FS, regardless 
					SL811Write(EP0XferLen, xferLen); 			// select next xfer length
					SL811Write(EP0Address, addr);           	// data buffer addr 
					SL811Write(IntStatus,INT_CLEAR);			// is a LS is on Hub.
					SL811Write(EP0Control,cmd);					// Enable USB transfer and re-arm
				}				

				//------------------------------------------------
				// Copy last IN token data pkt from prev transfer
				// Check if there was data available during the
				// last data transfer
				//------------------------------------------------
				if(bufLen)										
				{	
					SL811BufRead(((dataX&1)?data0:data1), usbstack.buffer, bufLen);
					usbstack.buffer += bufLen;								
				}

				//------------------------------------------------
				// Terminate on short packets, i.e. remainder!=0
				// a short packet or empty data packet OR when 
				// requested data len have completed, i.e.wLen=0
				// For a LOWSPEED device, the 1st device descp,
				// wPayload is default to 64-byte, LS device will
				// only send back a max of 8-byte device descp,
				// and host detect this as a short packet, and 
				// terminate with OUT status stage
				//------------------------------------------------
				if(remainder || !usbstack.wLen)
					break;
			}// PID IN							
		}
			
		//-------------------------NAK----------------------------
		if (result & EP0_NAK)									// NAK Detected
		{														
			if(usbstack.endpoint==0)										// on ep0 during enumeration of LS device
			{													// happen when slave is not fast enough,
				SL811Write(IntStatus,INT_CLEAR);				// clear interrupt status, need to
				SL811Write(EP0Control,cmd);						// re-arm and request for last cmd, IN token
                		result = 0;                                     // respond to NAK status only
			}
			else												// normal data endpoint, exit now !!! , non-zero ep
				break;											// main loop control the interval polling
		}
	
		//-----------------------TIMEOUT--------------------------
		if (result & EP0_TIMEOUT)								// TIMEOUT Detected
		{														
			if(usbstack.endpoint==0)										// happens when hub enumeration
			{
				if(++timeout >= TIMEOUT_RETRY)
				{	
				    timeout--;
					break;										// exit on the timeout detected	
				}
				SL811Write(IntStatus,INT_CLEAR);				// clear interrupt status, need to
				SL811Write(EP0Control,cmd);						// re-arm and request for last cmd again
			}
			else												
			{													// all other data endpoint, data transfer 
				bFlags.bits.TIMEOUT_ERR = TRUE;								// failed, set flag to terminate transfer
				break;											// happens when data transfer on a device
			}													// through the hub
		}

		//-----------------------STALL----------------------------
		if (result & EP0_STALL)  								// STALL detected
			return TRUE;										// for unsupported request.
																		
		//----------------------OVEFLOW---------------------------
		if (result & EP0_OVERFLOW)  							// OVERFLOW detected
			break;
		//-----------------------ERROR----------------------------
		if (result & EP0_ERROR)  								// ERROR detected
			break;
	}	// end of While(1)
   
	if (result & EP0_ACK) 	// on ACK transmission
		return TRUE;		// return OK

	return FALSE;			// fail transmission

}
//*****************************************************************************************
// Control Endpoint 0's USB Data Xfer
// ep0Xfer, endpoint 0 data transfer
//*****************************************************************************************
unsigned char ep0Xfer(void)
{
	usbstack.endpoint=0;
	//----------------------------------------------------
	// SETUP token with 8-byte request on endpoint 0
	//----------------------------------------------------
	usbstack.pid=PID_SETUP;
	usbstack.wLen=8;
	if (!usbXfer()) 
   		return FALSE;
	usbstack.pid  = PID_IN;
	//----------------------------------------------------
	// IN or OUT data stage on endpoint 0	
	//----------------------------------------------------