#include "rtl8019.h"

/*****************************************************************************
*  Module Name:       Realtek 8019AS Driver
*  
*  Created By:        Louis Beaudoin (www.embedded-creations.com)
*
*  Original Release:  September 21, 2002 
*
*  Module Description:  
*  Provides functions to initialize the Realtek 8019AS, and send and retreive
*  packets
*
*  November 16, 2003 - Louis Beaudoin
*    The rtl8019Write and Read functions/macros were changed to support
*      three methods of communcating with the NIC
*    Interfacing with the AVR ports changed from sbi/cbi/etc functions
*      to direct port names
*    Renamed functions to be more consistant with the two NIC drivers
*    Overrun function now retransmits if resend is set (thanks Krzysztof)
* 
*  November 15, 2002 - Louis Beaudoin
*    processRTL8019Interrupt() - bit mask mistake fixed
*
*  November 8, 2003 - Louis Beaudoin
*    Changed delay library function calls
*
*  September 30, 2002 - Louis Beaudoin
*    Receive functions modified to handle errors encountered when receiving a
*      fast data stream.  Functions now manually retreive data instead of
*      using the send packet command.  Interface improved by checking for
*      overruns and data in the buffer internally.
*    Corrected the overrun function - overrun flag was not reset after overrun
*    Added support for the Imagecraft Compiler
*    Added support to communicate with the NIC using general I/O ports
*
*****************************************************************************/


/*****************************************************************************
*  rtl8019Write( RTL_ADDRESS, RTL_DATA )
*  Args:        1. unsigned char RTL_ADDRESS - register offset of RTL register
*               2. unsigned char RTL_DATA - data to write to register
*  Created By:  Louis Beaudoin
*  Date:        September 21, 2002
*  Description: Writes byte to RTL8019 register.
*
*  Notes - If using the External SRAM Interface, performs a write to
*            address MEMORY_MAPPED_RTL8019_OFFSET + (RTL_ADDRESS<<8)
*            The address is sent in the non-multiplxed upper address port so
*            no latch is required.
*
*          If using general I/O ports, the data port is left in the input
*            state with pullups enabled
*
*****************************************************************************/
#if NIC_CONNECTION == MEMORY_MAPPED_HIGHADDR
#define rtl8019Write(RTL_ADDRESS,RTL_DATA) do{ *(volatile unsigned char *) \
                             (MEMORY_MAPPED_RTL8019_OFFSET \
                             + (((unsigned char)(RTL_ADDRESS)) << 8)) = \
                             (unsigned char)(RTL_DATA); } while(0)

#endif
                             
#if NIC_CONNECTION == MEMORY_MAPPED
#define rtl8019Write(RTL_ADDRESS,RTL_DATA) do{ *(volatile unsigned char *) \
                             (MEMORY_MAPPED_RTL8019_OFFSET \
                             + (unsigned char)(RTL_ADDRESS)) = \
                             (unsigned char)(RTL_DATA); } while(0)

#endif

#if NIC_CONNECTION == GENERAL_IO

void rtl8019Write(unsigned char address, unsigned char data)
{
    // assert the address, leaving the non-address pins intact
    address |= (RTL8019_ADDRESS_PORT & ~RTL8019_ADDRESS_MASK);
    RTL8019_ADDRESS_PORT = address;
    
	// set data bus as output and place data on bus
    RTL8019_DATA_DDR = 0xFF;
    RTL8019_DATA_PORT = data;
    
	// toggle write pin
    RTL8019_CONTROL_PORT &= ~_BV(RTL8019_CONTROL_WRITEPIN);
    nop();
    RTL8019_CONTROL_PORT |= _BV(RTL8019_CONTROL_WRITEPIN);

    
	// set data port back to input with pullups enabled
    RTL8019_DATA_DDR = 0x00;
    RTL8019_DATA_PORT = 0xFF;
}

#endif

/*****************************************************************************
*  rtl8019Read(RTL_ADDRESS)
*  Args:        unsigned char RTL_ADDRESS - register offset of RTL register
*  Created By:  Louis Beaudoin
*  Date:        September 21, 2002
*  Description: Reads byte from RTL8019 register
*
*  Notes - If using the External SRAM Interface, performs a read from
*            address MEMORY_MAPPED_RTL8019_OFFSET + (RTL_ADDRESS<<8)
*            The address is sent in the non-multiplxed upper address port so
*            no latch is required.
*
*          If using general I/O ports, the data port is assumed to already be
*            an input, and is left as an input port when done
*
*****************************************************************************/
#if NIC_CONNECTION == MEMORY_MAPPED_HIGHADDR
#define rtl8019Read(RTL_ADDRESS) (*(volatile unsigned char *) \
                       (MEMORY_MAPPED_RTL8019_OFFSET \
                       + (((unsigned char)(RTL_ADDRESS)) << 8)) )
#endif
                             
#if NIC_CONNECTION == MEMORY_MAPPED

#define rtl8019Read(RTL_ADDRESS) (*(volatile unsigned char *) \
                       (MEMORY_MAPPED_RTL8019_OFFSET \
                       + (unsigned char)(RTL_ADDRESS)) )
#endif

#if NIC_CONNECTION == GENERAL_IO

unsigned char rtl8019Read(unsigned char address)
{
    unsigned char byte;
   
    // assert the address, leaving the non-address pins intact
    address |= (RTL8019_ADDRESS_PORT & ~RTL8019_ADDRESS_MASK);
    RTL8019_ADDRESS_PORT = address;
   
    // assert read
    RTL8019_CONTROL_PORT &= ~_BV(RTL8019_CONTROL_READPIN);
    nop();
   
    // read in the data
    byte = RTL8019_DATA_PIN;

    // negate read
    RTL8019_CONTROL_PORT |= _BV(RTL8019_CONTROL_READPIN);

    return byte;
}

#endif                       



/*****************************************************************************
*  rtl8019SetupPorts(void);
*
*  Created By:  Louis Beaudoin
*  Date:        September 21, 2002
*  Description: Sets up the ports used for communication with the RTL8019 NIC
*                 (data bus, address bus, read, write, and reset)
*****************************************************************************/
void rtl8019SetupPorts(void)
{

#if NIC_CONNECTION == GENERAL_IO

    // make the address port output
	RTL8019_ADDRESS_DDR = RTL8019_ADDRESS_MASK;
    
    // make the data port input with pull-ups
    RTL8019_DATA_PORT = 0xFF;

	// make the control port read and write pins outputs and asserted
	RTL8019_CONTROL_DDR |= _BV(RTL8019_CONTROL_READPIN);
    RTL8019_CONTROL_DDR |= _BV(RTL8019_CONTROL_WRITEPIN);
	          
	RTL8019_CONTROL_PORT |= _BV(RTL8019_CONTROL_READPIN);
	RTL8019_CONTROL_PORT |= _BV(RTL8019_CONTROL_WRITEPIN);

#else

  	// enable external SRAM interface - no wait states
    MCUCR |= _BV(SRE);

#endif

	// enable output pin for Resetting the RTL8019
	RTL8019_RESET_DDR |= _BV(RTL8019_RESET_PIN);
}



/*****************************************************************************
*  HARD_RESET_RTL8019()
*
*  Created By:  Louis Beaudoin
*  Date:        September 21, 2002
*  Description: Simply toggles the pin that resets the NIC
*****************************************************************************/
#define HARD_RESET_RTL8019() do{ RTL8019_RESET_PORT |= _BV(RTL8019_RESET_PIN);\
                                delay_ms(10); \
                                RTL8019_RESET_PORT &= ~_BV(RTL8019_RESET_PIN);}\
                                while(0)



/*****************************************************************************
*  rtl8019Overrun(void);
*
*  Created By:  Louis Beaudoin
*  Date:        September 21, 2002
*  Description: "Canned" receive buffer overrun function originally from
*                 a National Semiconductor appnote
*  Notes:       This function must be called before retreiving packets from
*                 the NIC if there is a buffer overrun
*****************************************************************************/
void rtl8019Overrun(void);




//******************************************************************
//*	REALTEK CONTROL REGISTER OFFSETS
//*   All offsets in Page 0 unless otherwise specified
//*	  All functions accessing CR must leave CR in page 0 upon exit
//******************************************************************
#define CR		 	0x00
#define PSTART		0x01
#define PAR0      	0x01    // Page 1
#define CR9346    	0x01    // Page 3
#define PSTOP		0x02
#define BNRY		0x03
#define TSR			0x04
#define TPSR		0x04
#define TBCR0		0x05
#define NCR			0x05
#define TBCR1		0x06
#define ISR			0x07
#define CURR		0x07   // Page 1
#define RSAR0		0x08
#define CRDA0		0x08
#define RSAR1		0x09
#define CRDA1		0x09
#define RBCR0		0x0A
#define RBCR1		0x0B
#define RSR			0x0C
#define RCR			0x0C
#define TCR			0x0D
#define CNTR0		0x0D
#define DCR			0x0E
#define CNTR1		0x0E
#define IMR			0x0F
#define CNTR2		0x0F
#define RDMAPORT  	0x10
#define RSTPORT   	0x18
#define CONFIG2     0x05    // page 3
#define CONFIG3     0x06    // page 3
#define RTL_EECR        0x01    // page 3



/*****************************************************************************
*
* RTL ISR Register Bits
*
*****************************************************************************/
#define ISR_RST	7
#define ISR_OVW 4
#define ISR_PRX 0
#define ISR_RDC 6
#define ISR_PTX 1


/*****************************************************************************
*
*  RTL Register Initialization Values
*
*****************************************************************************/
// RCR : accept broadcast packets and packets destined to this MAC
//         drop short frames and receive errors
#define RCR_INIT		0x04

// TCR : default transmit operation - CRC is generated 
#define TCR_INIT		0x00

// DCR : allows send packet to be used for packet retreival
//         FIFO threshold: 8-bits (works)
//         8-bit transfer mode
#define DCR_INIT		0x58

// IMR : interrupt enabled for receive and overrun events
#define IMR_INIT		0x11

// buffer boundaries - transmit has 6 256-byte pages
//   receive has 26 256-byte pages