/***************************************************************************
 * This code and information is provided "as is" without warranty of any   *
 * kind, either expressed or implied, including but not limited to the     *
 * implied warranties of merchantability and/or fitness for a particular   *
 * purpose.                                                                *
 *                                                                         *
 * Copyright (C) 2006 Teridian Semiconductor Corp. All Rights Reserved.    *
 ***************************************************************************/
//**************************************************************************
//  DESCRIPTION: 71M6521B POWER METER - Serial EEPROM Routines. 
// 
//  AUTHOR:  RGV
//
//  HISTORY: See end of file
//**************************************************************************
// File: IICEEP.C
// This implements a polling IIC bus interface using the chip's
// EEPROM interface.
//               
//**************************************************************************
// IIC API.
//
#include "options.h"
#if I2C_POLLED && !I2C_FAST
#include "iic.h"

// change this stuff for new hardware
// more than 31 cycle delay, so EECTRL has valid status at 4.9Mhz MPU clock
// and so start sequence is correct after stop sequence (requires 20 cycles).
static volatile uint8_t delay;
#pragma save
#pragma NOAREGS
void delay_sub(void) small reentrant // call is 12 cycles
{
    delay = 0;  // 12 cycles, CLR
    delay = 1;  // 12 cycles, SET
}                   // ret is 5 cycles ; total is 41 cycles, at least
#pragma restore

#define DELAY_SUB \
delay_sub()

// waits for busy bit to indicate that the previous command is complete
#define BUSY_WAIT \
    do { \
        status = EECTRL; \
    } while((status & EE_BUSY) != 0)

// NO-OP reduces activity, somewhat reducing power use
// It clears busy so fast that the unbusy loop doesn't catch it.
#define NOOP \
    BUSY_WAIT; \
    EECTRL = EE_NOOP; \
    DELAY_SUB

// The start condition has the data change while the clock is high,
// but ends with the clock low so the clock can clock bits.
// If sent immediately after a stop, a 20 cycle wait has to be after
// busy becomes zero.
#define START_CONDITION \
    BUSY_WAIT; \
    DELAY_SUB; \
    EECTRL = EE_START; \
    DELAY_SUB

// the stop condition makes the data go high when the clock is high
// It has to end with both lines high.
// It clears busy so fast that the unbusy loop doesn't catch it.
#define STOP_CONDITION \
    BUSY_WAIT; \
    EECTRL = EE_STOP; \
    DELAY_SUB; \
    NOOP

#define ACK (status & EE_RX_ACK)

#define PUT_BYTE(_b_) \
    EEDATA = _b_; \
    EECTRL = EE_TX; \
    DELAY_SUB; \
    BUSY_WAIT

#define GET_BYTE(_b_) \
    EECTRL = EE_RCV_ACK; \
    DELAY_SUB; \
    BUSY_WAIT; \
    _b_ = EEDATA

#define GET_BYTE_NO_ACK(_b_) \
    EECTRL = EE_RCV; \
    DELAY_SUB; \
    BUSY_WAIT; \
    _b_ = EEDATA

#pragma save
#pragma NOAREGS
void IICInit(void) small reentrant
{
    uint8_t status;

    #if TRACE10 || M6520
    if ((LCDX & LCD_NUM) > 16) // DIO_4 and DIO_5 may not be LCD segments
    {
        LCDX = 16 | (LCDX & ~LCD_NUM);
    }
    #elif M6530
    #else
    #error unknown device
    #endif
    EX_EEPROM  = FALSE;           // Disable EEPROM non-busy interrupt.
    DIO = (DIO & ~DIO_EEX) | DIO_EEX_2W; // DIO_4 and DIO_5 become EEPROM interface.
    STOP_CONDITION;
}
#pragma restore

// stub the "get a bit" function used to reset some parts
#pragma save
#pragma NOAREGS
uint8_t IICGetBit(void) small reentrant
{
    return 0;
}
#pragma restore
// start of portable code

// an IIC bus's start condition
#pragma save
#pragma NOAREGS
void IICStart(void) small reentrant
{
    uint8_t status;
    EX_EEPROM  = FALSE;           // Disable EEPROM non-busy interrupt.
    DIO = (DIO & ~DIO_EEX) | DIO_EEX_2W; // DIO_4 and DIO_5 become EEPROM interface.
    START_CONDITION;
}
#pragma restore

// an IIC bus's ending condition
#pragma save
#pragma NOAREGS
void IICStop(void) small reentrant
{
    uint8_t status;
    STOP_CONDITION;
    DIO = (DIO & ~DIO_EEX); // DIO_4 and DIO_5 become DIOs.
}
#pragma restore

// transmit a counted string of bytes to an IIC bus
#pragma save
#pragma NOAREGS
uint8_t IICWrite(uint8x_t *pchOut, int16_t cnt) small reentrant
{
    uint8_t b, status;
    uint8_t ack;

    BUSY_WAIT; // until previous command completes
    for(ack = 0; (0 == ack) && (cnt > 0); --cnt)
    {
        b = *pchOut++;
        PUT_BYTE(b);
        ack = ACK ? 1 : 0; // get the ack bit
    }
    NOOP; // stop the state machine

    return ack;
}
#pragma restore

#if CLI
// transmit a counted string of identical bytes to an IIC bus
#pragma save
#pragma NOAREGS
uint8_t IICPad(int16_t cnt, uint8_t bIn) small reentrant
{
    uint8_t b, status;
    uint8_t ack;

    b = bIn;

    BUSY_WAIT; // until previous command completes
    for(ack = 0; (0 == ack) && (cnt > 0); --cnt)
    {
        PUT_BYTE(b);
        ack = ACK ? 1 : 0; // get the ack bit
    }
    NOOP; // stop the state machine
    return ack;
}
#pragma restore
#endif

// receive a counted string of bytes from an IIC bus
#pragma save
#pragma NOAREGS
void IICRead(uint8x_t *pchIn, int16_t cnt) small reentrant
{
    uint8_t b, status;

    if (cnt > 0)
    {
        BUSY_WAIT; // until previous command completes
        while(cnt > 0)
        {
            if (--cnt == 0)
            {
                GET_BYTE_NO_ACK(b); // get the last byte from the bus
                *pchIn++ = b; // store it
                break;
            }
            else
            {
                GET_BYTE(b); // get a byte from the bus
                *pchIn++ = b; // store it
            }
        }
    
        NOOP; // stop the state machine
    }
}
#pragma restore

#endif // EEPROM

/***************************************************************************
 * $Log: iiceep.c,v $
 * Revision 1.23  2006/10/13 00:47:29  tvander
 * Removed compile options for 6530, 6515;
 * renamed 6511 and 6513 to trace11 and trace13;
 * Binary verified unchanged from previous version.
 *
 * Revision 1.22  2006/09/09 01:09:33  gmikef
 * *** empty log message ***
 *
 * Revision 1.21  2006/06/29 00:55:48  tvander
 * Marked NOAREGS on reentrant routines that needed it.
 *
 * Revision 1.20  2006/06/15 16:36:56  tvander
 * Fixed reentrancy on iiceep.c and eepromp.c
 * Made parallel code changes to microwire eeprom drivers.
 *
 * Revision 1.19  2006/05/18 23:18:45  tvander
 * 16K and 32K
 * First cut at new requirements.
 * 32K 6521 is grossly tested.
 * All others have a clean compile with C51 8.02
 *
 * Revision 1.18  2006/03/08 00:00:57  tvander
 * Revised IO so that multiplexed interrupts are centralized in io65xx.c
 * Added default interrupts to io65xx.c
 * Clean build.
 * Tested CE, serial.
 * interrupting EEPROM driver fails.
 *
 * Revision 1.17  2006/03/06 03:31:32  Michael T. Fischer
 * More 6530 prep.
 *
 * Revision 1.16  2006/03/03 11:26:02  Michael T. Fischer
 * Prep for 6530 LCD, etc.
 *
 * Revision 1.15  2006/01/16 20:11:22  tvander
 * Clean Keil build, all versions
 *
 * Revision 1.13  2005/11/05 02:14:00  tvander
 * Fixed build
 *
 * Revision 1.12  2005/11/05 01:56:27  tvander
 * Added EEPROM erase; Note uwreep.c is not working; don't know why.
 *
 * Revision 1.11  2005/10/31 17:37:59  tvander
 * Includes improved EEPROM code with uwire.
 * Clean build, all build trees (Thank-you, Mike!)
 *
 * Revision 1.10  2005/10/20 18:39:41  tvander
 * Ported 2-wire EEPROM code from 6511/6513, including interrupting version, polling version for DIO, and polling version using the 2-wire logic.
 *
 * Revision 1.9  2005/09/22 23:45:05  tvander
 * Clean build all models and unit tests, updated copyright to be fore Teridian
 *
 * Revision 1.8  2005/08/28 02:13:49  gmikef
 * *** empty log message ***
 *
 * Revision 1.7  2005/08/16 02:28:30  gmikef
 * Remapped LCD for 6520 Eval Board.
 * Mapped CE code location to address of 'CeCode'.
 *
 * Revision 1.6  2005/05/03 00:39:44  tvander
 * Incorporated event reporting in tmr0,tmr1 and unit tests.
 * Retested stm, trm0, tmr1.
 * Incorporated untested changes in io651x.h
 *
 * Revision 1.5  2005/04/21 01:59:54  gmikef
 * *** empty log message ***
 *
 * Revision 1.7  2005/04/09 02:04:25  gmikef
 * *** empty log message ***
 *
 * Revision 1.4  2005/03/23 19:19:31  tvander
 * Added untested timer functions.
 * Updated iicdio and iiceep to reflect improvements in 6510 code.
 * ser0 and ser1 updated to provide features for flag.
 *
 * Revision 1.3  2005/03/22 00:56:00  tvander
 * Rolled date
 * Changed misc.c to disable interrupts in Ce_Int_Enable().
 * Changed calls to memcpy_xp to never write outside the buffer.
 * Changed the help files to be more accurate.
 *
 * Revision 1.3  2005/03/12 00:16:59  tvander
 * Integrated memory types.
 *
 * Revision 1.2  2005/03/11 22:57:03  tvander
 * Added bool, and 8/16/32 data structures
 *
 * Revision 1.1  2005/03/11 22:19:15  tvander
 * *** empty log message ***
 *
 * Revision 1.2  2005/02/17 18:32:26  tvander
 * Added automatic check-in logging to all source code.
 *
 * 2004 DECEMBER 22;    First Version
 *
 * Revision 1.1  2005/02/01 20:04:41  tvander
 * Reorganization
 *
 * Revision 1.4  2005/01/26 19:51:48  tvander
 * Added update log
 *
 * Copyright (C) 2005 Teridian Semiconductor Corp. All Rights Reserved.    *
 * this program is fully protected by the United States copyright          *
 * laws and is the property of Teridian Semiconductor Corporation.         *
 ***************************************************************************/