628 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			628 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			C
		
	
	
	
| /* I2cCore.c - MPC8220 PPC I2C Library */
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| 
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| /* Copyright 2004      Freescale Semiconductor, Inc. */
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| 
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| /*
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| modification history
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| --------------------
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| 01c,29jun04,tcl	 1.3	removed CR. Added two bytes offset support.
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| 01b,19jan04,tcl	 1.2	removed i2cMsDelay and sysDecGet. renamed i2cMsDelay
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| 			back to sysMsDelay
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| 01a,19jan04,tcl	 1.1	created and seperated from i2c.c
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| */
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| 
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| /*
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| DESCRIPTION
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| This file contain I2C low level handling library functions
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| */
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| 
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| #include <stdio.h>
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| #include <stdlib.h>
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| #include <string.h>
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| #include <vxWorks.h>
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| #include <sysLib.h>
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| #include <iosLib.h>
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| #include <logLib.h>
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| #include <tickLib.h>
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| 
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| /* BSP Includes */
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| #include "config.h"
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| #include "mpc8220.h"
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| #include "i2cCore.h"
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| 
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| #ifdef DEBUG_I2CCORE
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| int I2CCDbg = 0;
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| #endif
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| 
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| #define ABS(x)	((x < 0)? -x : x)
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| 
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| char *I2CERR[16] = {
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| 	"Transfer in Progress\n",	/* 0 */
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| 	"Transfer complete\n",
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| 	"Not Addressed\n",		/* 2 */
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| 	"Addressed as a slave\n",
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| 	"Bus is Idle\n",		/* 4 */
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| 	"Bus is busy\n",
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| 	"Arbitration Lost\n",		/* 6 */
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| 	"Arbitration on Track\n",
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| 	"Slave receive, master writing to slave\n",	/* 8 */
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| 	"Slave transmit, master reading from slave\n",
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| 	"Interrupt is pending\n",	/* 10 */
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| 	"Interrupt complete\n",
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| 	"Acknowledge received\n",	/* 12 */
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| 	"No acknowledge received\n",
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| 	"Unknown status\n",		/* 14 */
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| 	"\n"
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| };
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| 
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| /******************************************************************************
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|  *
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|  * chk_status - Check I2C status bit
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|  *
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|  * RETURNS: OK, or ERROR if the bit encounter
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|  *
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|  */
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| 
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| STATUS chk_status (PSI2C pi2c, UINT8 sta_bit, UINT8 truefalse)
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| {
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| 	int i, status = 0;
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| 
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| 	for (i = 0; i < I2C_POLL_COUNT; i++) {
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| 		if ((pi2c->sr & sta_bit) == (truefalse ? sta_bit : 0))
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| 			return (OK);
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| 	}
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| 
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| 	I2CCDBG (L2, ("--- sr %x stabit %x truefalse %d\n",
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| 		      pi2c->sr, sta_bit, truefalse, 0, 0, 0));
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| 
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| 	if (i == I2C_POLL_COUNT) {
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| 		switch (sta_bit) {
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| 		case I2C_STA_CF:
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| 			status = 0;
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| 			break;
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| 		case I2C_STA_AAS:
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| 			status = 2;
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| 			break;
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| 		case I2C_STA_BB:
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| 			status = 4;
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| 			break;
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| 		case I2C_STA_AL:
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| 			status = 6;
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| 			break;
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| 		case I2C_STA_SRW:
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| 			status = 8;
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| 			break;
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| 		case I2C_STA_IF:
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| 			status = 10;
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| 			break;
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| 		case I2C_STA_RXAK:
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| 			status = 12;
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| 			break;
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| 		default:
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| 			status = 14;
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| 			break;
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| 		}
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| 
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| 		if (!truefalse)
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| 			status++;
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| 
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| 		I2CCDBG (NO, ("--- status %d\n", status, 0, 0, 0, 0, 0));
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| 		I2CCDBG (NO, (I2CERR[status], 0, 0, 0, 0, 0, 0));
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| 	}
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| 
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| 	return (ERROR);
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| }
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| 
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| /******************************************************************************
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|  *
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|  * I2C Enable - Enable the I2C Controller
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|  *
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|  */
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| STATUS i2c_enable (SI2C * pi2c, PI2CSET pi2cSet)
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| {
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| 	int fdr = pi2cSet->bit_rate;
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| 	UINT8 adr = pi2cSet->i2c_adr;
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| 
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| 	I2CCDBG (L2, ("i2c_enable fdr %d adr %x\n", fdr, adr, 0, 0, 0, 0));
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| 
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| 	i2c_clear (pi2c);	/* Clear FDR, ADR, SR and CR reg */
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| 
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| 	SetI2cFDR (pi2c, fdr);	/* Frequency			*/
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| 	pi2c->adr = adr;
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| 
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| 	pi2c->cr = I2C_CTL_EN;	/* Set Enable			*/
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| 
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| 	/*
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| 	   The I2C bus should be in Idle state. If the bus is busy,
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| 	   clear the STA bit in control register
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| 	 */
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| 	if (chk_status (pi2c, I2C_STA_BB, 0) != OK) {
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| 		if ((pi2c->cr & I2C_CTL_STA) == I2C_CTL_STA)
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| 			pi2c->cr &= ~I2C_CTL_STA;
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| 
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| 		/* Check again if it is still busy, return error if found */
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| 		if (chk_status (pi2c, I2C_STA_BB, 1) == OK)
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| 			return ERROR;
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| 	}
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| 
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| 	return (OK);
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| }
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| 
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| /******************************************************************************
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|  *
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|  * I2C Disable - Disable the I2C Controller
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|  *
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|  */
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| STATUS i2c_disable (PSI2C pi2c)
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| {
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| 	i2c_clear (pi2c);
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| 
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| 	pi2c->cr &= I2C_CTL_EN; /* Disable I2c			*/
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| 
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| 	if ((pi2c->cr & I2C_CTL_STA) == I2C_CTL_STA)
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| 		pi2c->cr &= ~I2C_CTL_STA;
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| 
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| 	if (chk_status (pi2c, I2C_STA_BB, 0) != OK)
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| 		return ERROR;
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| 
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| 	return (OK);
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| }
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| 
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| /******************************************************************************
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|  *
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|  * I2C Clear - Clear the I2C Controller
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|  *
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|  */
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| STATUS i2c_clear (PSI2C pi2c)
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| {
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| 	pi2c->adr = 0;
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| 	pi2c->fdr = 0;
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| 	pi2c->cr = 0;
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| 	pi2c->sr = 0;
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| 
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| 	return (OK);
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| }
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| 
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| 
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| STATUS i2c_start (PSI2C pi2c, PI2CSET pi2cSet)
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| {
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| #ifdef TWOBYTES
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| 	UINT16 ByteOffset = pi2cSet->str_adr;
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| #else
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| 	UINT8 ByteOffset = pi2cSet->str_adr;
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| #endif
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| #if 1
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| 	UINT8 tmp = 0;
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| #endif
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| 	UINT8 Addr = pi2cSet->slv_adr;
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| 
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| 	pi2c->cr |= I2C_CTL_STA;	/* Generate start signal	*/
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| 
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| 	if (chk_status (pi2c, I2C_STA_BB, 1) != OK)
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| 		return ERROR;
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| 
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| 	/* Write slave address */
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| 	if (i2c_writebyte (pi2c, &Addr) != OK) {
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| 		i2c_stop (pi2c);	/* Disable I2c			*/
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| 		return ERROR;
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| 	}
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| #ifdef TWOBYTES
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| #   if 0
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| 	/* Issue the offset to start */
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| 	if (i2c_write2byte (pi2c, &ByteOffset) != OK) {
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| 		i2c_stop (pi2c);	/* Disable I2c			*/
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| 		return ERROR;
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| 	}
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| #endif
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| 	tmp = (ByteOffset >> 8) & 0xff;
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| 	if (i2c_writebyte (pi2c, &tmp) != OK) {
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| 		i2c_stop (pi2c);	/* Disable I2c			*/
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| 		return ERROR;
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| 	}
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| 	tmp = ByteOffset & 0xff;
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| 	if (i2c_writebyte (pi2c, &tmp) != OK) {
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| 		i2c_stop (pi2c);	/* Disable I2c			*/
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| 		return ERROR;
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| 	}
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| #else
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| 	if (i2c_writebyte (pi2c, &ByteOffset) != OK) {
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| 		i2c_stop (pi2c);	/* Disable I2c			*/
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| 		return ERROR;
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| 	}
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| #endif
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| 
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| 	return (OK);
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| }
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| 
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| STATUS i2c_stop (PSI2C pi2c)
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| {
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| 	pi2c->cr &= ~I2C_CTL_STA;	/* Generate stop signal		*/
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| 	if (chk_status (pi2c, I2C_STA_BB, 0) != OK)
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| 		return ERROR;
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| 
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| 	return (OK);
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| }
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| 
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| /******************************************************************************
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|  *
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|  * Read Len bytes to the location pointed to by *Data from the device
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|  * with address Addr.
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|  */
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| int i2c_readblock (SI2C * pi2c, PI2CSET pi2cSet, UINT8 * Data)
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| {
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| 	int i = 0;
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| 	UINT8 Tmp;
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| 
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| /*    UINT8 ByteOffset = pi2cSet->str_adr; not used? */
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| 	UINT8 Addr = pi2cSet->slv_adr;
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| 	int Length = pi2cSet->xfer_size;
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| 
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| 	I2CCDBG (L1, ("i2c_readblock addr %x data 0x%08x len %d offset %d\n",
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| 		      Addr, (int) Data, Length, ByteOffset, 0, 0));
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| 
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| 	if (pi2c->sr & I2C_STA_AL) {	/* Check if Arbitration lost	*/
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| 		I2CCDBG (FN, ("Arbitration lost\n", 0, 0, 0, 0, 0, 0));
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| 		pi2c->sr &= ~I2C_STA_AL;	/* Clear Arbitration status bit */
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| 		return ERROR;
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| 	}
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| 
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| 	pi2c->cr |= I2C_CTL_TX; /* Enable the I2c for TX, Ack	*/
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| 
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| 	if (i2c_start (pi2c, pi2cSet) == ERROR)
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| 		return ERROR;
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| 
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| 	pi2c->cr |= I2C_CTL_RSTA;	/* Repeat Start */
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| 
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| 	Tmp = Addr | 1;
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| 
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| 	if (i2c_writebyte (pi2c, &Tmp) != OK) {
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| 		i2c_stop (pi2c);	/* Disable I2c	*/
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| 		return ERROR;
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| 	}
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| 
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| 	if (((pi2c->sr & 0x07) == 0x07) || (pi2c->sr & 0x01))
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| 		return ERROR;
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| 
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| 	pi2c->cr &= ~I2C_CTL_TX;	/* Set receive mode	*/
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| 
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| 	if (((pi2c->sr & 0x07) == 0x07) || (pi2c->sr & 0x01))
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| 		return ERROR;
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| 
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| 	/* Dummy Read */
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| 	if (i2c_readbyte (pi2c, &Tmp, &i) != OK) {
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| 		i2c_stop (pi2c);	/* Disable I2c	*/
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| 		return ERROR;
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| 	}
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| 
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| 	i = 0;
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| 	while (Length) {
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| 		if (Length == 2)
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| 			pi2c->cr |= I2C_CTL_TXAK;
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| 
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| 		if (Length == 1)
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| 			pi2c->cr &= ~I2C_CTL_STA;
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| 
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| 		if (i2c_readbyte (pi2c, Data, &Length) != OK) {
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| 			return i2c_stop (pi2c);
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| 		}
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| 		i++;
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| 		Length--;
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| 		Data++;
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| 	}
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| 
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| 	if (i2c_stop (pi2c) == ERROR)
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| 		return ERROR;
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| 
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| 	return i;
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| }
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| 
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| STATUS i2c_writeblock (SI2C * pi2c, PI2CSET pi2cSet, UINT8 * Data)
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| {
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| 	int Length = pi2cSet->xfer_size;
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| 
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| #ifdef TWOBYTES
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| 	UINT16 ByteOffset = pi2cSet->str_adr;
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| #else
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| 	UINT8 ByteOffset = pi2cSet->str_adr;
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| #endif
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| 	int j, k;
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| 
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| 	I2CCDBG (L2, ("i2c_writeblock\n", 0, 0, 0, 0, 0, 0));
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| 
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| 	if (pi2c->sr & I2C_STA_AL) {
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| 		/* Check if arbitration lost */
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| 		I2CCDBG (L2, ("Arbitration lost\n", 0, 0, 0, 0, 0, 0));
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| 		pi2c->sr &= ~I2C_STA_AL;	/* Clear the condition	*/
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| 		return ERROR;
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| 	}
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| 
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| 	pi2c->cr |= I2C_CTL_TX; /* Enable the I2c for TX, Ack	*/
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| 
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| 	/* Do the not even offset first */
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| 	if ((ByteOffset % 8) != 0) {
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| 		int remain;
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| 
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| 		if (Length > 8) {
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| 			remain = 8 - (ByteOffset % 8);
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| 			Length -= remain;
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| 
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| 			pi2cSet->str_adr = ByteOffset;
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| 
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| 			if (i2c_start (pi2c, pi2cSet) == ERROR)
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| 				return ERROR;
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| 
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| 			for (j = ByteOffset; j < remain; j++) {
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| 				if (i2c_writebyte (pi2c, Data++) != OK)
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| 					return ERROR;
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| 			}
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| 
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| 			if (i2c_stop (pi2c) == ERROR)
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| 				return ERROR;
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| 
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| 			sysMsDelay (32);
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| 
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| 			/* Update the new ByteOffset */
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| 			ByteOffset += remain;
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| 		}
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| 	}
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| 
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| 	for (j = ByteOffset, k = 0; j < (Length + ByteOffset); j++) {
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| 		if ((j % 8) == 0) {
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| 			pi2cSet->str_adr = j;
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| 			if (i2c_start (pi2c, pi2cSet) == ERROR)
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| 				return ERROR;
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| 		}
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| 
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| 		k++;
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| 
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| 		if (i2c_writebyte (pi2c, Data++) != OK)
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| 			return ERROR;
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| 
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| 		if ((j == (Length - 1)) || ((k % 8) == 0)) {
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| 			if (i2c_stop (pi2c) == ERROR)
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| 				return ERROR;
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| 
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| 			sysMsDelay (50);
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| 		}
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| 
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| 	}
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| 
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| 	return k;
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| }
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| 
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| STATUS i2c_readbyte (SI2C * pi2c, UINT8 * readb, int *index)
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| {
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| 	pi2c->sr &= ~I2C_STA_IF;	/* Clear Interrupt Bit	*/
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| 	*readb = pi2c->dr;		/* Read a byte		*/
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| 
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| 	/*
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| 	   Set I2C_CTRL_TXAK will cause Transfer pending and
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| 	   set I2C_CTRL_STA will cause Interrupt pending
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| 	 */
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| 	if (*index != 2) {
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| 		if (chk_status (pi2c, I2C_STA_CF, 1) != OK)	/* Transfer not complete?	*/
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| 			return ERROR;
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| 	}
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| 
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| 	if (*index != 1) {
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| 		if (chk_status (pi2c, I2C_STA_IF, 1) != OK)
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| 			return ERROR;
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| 	}
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| 
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| 	return (OK);
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| }
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| 
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| 
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| STATUS i2c_writebyte (SI2C * pi2c, UINT8 * writeb)
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| {
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| 	pi2c->sr &= ~I2C_STA_IF;	/* Clear Interrupt	*/
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| 	pi2c->dr = *writeb;		/* Write a byte		*/
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| 
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| 	if (chk_status (pi2c, I2C_STA_CF, 1) != OK)	/* Transfer not complete?	*/
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| 		return ERROR;
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| 
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| 	if (chk_status (pi2c, I2C_STA_IF, 1) != OK)
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| 		return ERROR;
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| 
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| 	return OK;
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| }
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| 
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| STATUS i2c_write2byte (SI2C * pi2c, UINT16 * writeb)
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| {
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| 	UINT8 data;
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| 
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| 	data = (UINT8) ((*writeb >> 8) & 0xff);
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| 	if (i2c_writebyte (pi2c, &data) != OK)
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| 		return ERROR;
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| 	data = (UINT8) (*writeb & 0xff);
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| 	if (i2c_writebyte (pi2c, &data) != OK)
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| 		return ERROR;
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| 	return OK;
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| }
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| 
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| /* FDR table base on 33Mhz - more detail please refer to Odini2c_dividers.xls
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| FDR FDR scl sda scl2tap2
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| 510 432 tap tap tap tap scl_per	    sda_hold	I2C Freq    0	1   2	3   4	5
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| 000 000 9   3	4   1	28 Clocks   9 Clocks	1190 KHz    0	0   0	0   0	0
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| 000 001 9   3	4   2	44 Clocks   11 Clocks	758 KHz	    0	0   1	0   0	0
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| 000 010 9   3	6   4	80 Clocks   17 Clocks	417 KHz	    0	0   0	1   0	0
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| 000 011 9   3	6   8	144 Clocks  25 Clocks	231 KHz	    0	0   1	1   0	0
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| 000 100 9   3	14  16	288 Clocks  49 Clocks	116 KHz	    0	0   0	0   1	0
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| 000 101 9   3	30  32	576 Clocks  97 Clocks	58 KHz	    0	0   1	0   1	0
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| 000 110 9   3	62  64	1152 Clocks 193 Clocks	29 KHz	    0	0   0	1   1	0
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| 000 111 9   3	126 128 2304 Clocks 385 Clocks	14 KHz	    0	0   1	1   1	0
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| 001 000 10  3	4   1	30 Clocks   9 Clocks	1111 KHz1   0	0   0	0   0
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| 001 001 10  3	4   2	48 Clocks   11 Clocks	694 KHz	    1	0   1	0   0	0
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| 001 010 10  3	6   4	88 Clocks   17 Clocks	379 KHz	    1	0   0	1   0	0
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| 001 011 10  3	6   8	160 Clocks  25 Clocks	208 KHz	    1	0   1	1   0	0
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| 001 100 10  3	14  16	320 Clocks  49 Clocks	104 KHz	    1	0   0	0   1	0
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| 001 101 10  3	30  32	640 Clocks  97 Clocks	52 KHz	    1	0   1	0   1	0
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| 001 110 10  3	62  64	1280 Clocks 193 Clocks	26 KHz	    1	0   0	1   1	0
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| 001 111 10  3	126 128 2560 Clocks 385 Clocks	13 KHz	    1	0   1	1   1	0
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| 010 000 12  4	4   1	34 Clocks   10 Clocks	980 KHz	    0	1   0	0   0	0
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| 010 001 12  4	4   2	56 Clocks   13 Clocks	595 KHz	    0	1   1	0   0	0
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| 010 010 12  4	6   4	104 Clocks  21 Clocks	321 KHz	    0	1   0	1   0	0
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| 010 011 12  4	6   8	192 Clocks  33 Clocks	174 KHz	    0	1   1	1   0	0
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| 010 100 12  4	14  16	384 Clocks  65 Clocks	87 KHz	    0	1   0	0   1	0
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| 010 101 12  4	30  32	768 Clocks  129 Clocks	43 KHz	    0	1   1	0   1	0
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| 010 110 12  4	62  64	1536 Clocks 257 Clocks	22 KHz	    0	1   0	1   1	0
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| 010 111 12  4	126 128 3072 Clocks 513 Clocks	11 KHz	    0	1   1	1   1	0
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| 011 000 15  4	4   1	40 Clocks   10 Clocks	833 KHz	    1	1   0	0   0	0
 | |
| 011 001 15  4	4   2	68 Clocks   13 Clocks	490 KHz	    1	1   1	0   0	0
 | |
| 011 010 15  4	6   4	128 Clocks  21 Clocks	260 KHz	    1	1   0	1   0	0
 | |
| 011 011 15  4	6   8	240 Clocks  33 Clocks	139 KHz	    1	1   1	1   0	0
 | |
| 011 100 15  4	14  16	480 Clocks  65 Clocks	69 KHz	    1	1   0	0   1	0
 | |
| 011 101 15  4	30  32	960 Clocks  129 Clocks	35 KHz	    1	1   1	0   1	0
 | |
| 011 110 15  4	62  64	1920 Clocks 257 Clocks	17 KHz	    1	1   0	1   1	0
 | |
| 011 111 15  4	126 128 3840 Clocks 513 Clocks	9 KHz	    1	1   1	1   1	0
 | |
| 100 000 5   1	4   1	20 Clocks   7 Clocks	1667 KHz    0	0   0	0   0	1
 | |
| 100 001 5   1	4   2	28 Clocks   7 Clocks	1190 KHz    0	0   1	0   0	1
 | |
| 100 010 5   1	6   4	48 Clocks   9 Clocks	694 KHz	    0	0   0	1   0	1
 | |
| 100 011 5   1	6   8	80 Clocks   9 Clocks	417 KHz	    0	0   1	1   0	1
 | |
| 100 100 5   1	14  16	160 Clocks  17 Clocks	208 KHz	    0	0   0	0   1	1
 | |
| 100 101 5   1	30  32	320 Clocks  33 Clocks	104 KHz	    0	0   1	0   1	1
 | |
| 100 110 5   1	62  64	640 Clocks  65 Clocks	52 KHz	    0	0   0	1   1	1
 | |
| 100 111 5   1	126 128 1280 Clocks 129 Clocks	26 KHz	    0	0   1	1   1	1
 | |
| 101 000 6   1	4   1	22 Clocks   7 Clocks	1515 KHz    1	0   0	0   0	1
 | |
| 101 001 6   1	4   2	32 Clocks   7 Clocks	1042 KHz    1	0   1	0   0	1
 | |
| 101 010 6   1	6   4	56 Clocks   9 Clocks	595 KHz	    1	0   0	1   0	1
 | |
| 101 011 6   1	6   8	96 Clocks   9 Clocks	347 KHz	    1	0   1	1   0	1
 | |
| 101 100 6   1	14  16	192 Clocks  17 Clocks	174 KHz	    1	0   0	0   1	1
 | |
| 101 101 6   1	30  32	384 Clocks  33 Clocks	87 KHz	    1	0   1	0   1	1
 | |
| 101 110 6   1	62  64	768 Clocks  65 Clocks	43 KHz	    1	0   0	1   1	1
 | |
| 101 111 6   1	126 128 1536 Clocks 129 Clocks	22 KHz	    1	0   1	1   1	1
 | |
| 110 000 7   2	4   1	24 Clocks   8 Clocks	1389 KHz    0	1   0	0   0	1
 | |
| 110 001 7   2	4   2	36 Clocks   9 Clocks	926 KHz	    0	1   1	0   0	1
 | |
| 110 010 7   2	6   4	64 Clocks   13 Clocks	521 KHz	    0	1   0	1   0	1
 | |
| 110 011 7   2	6   8	112 Clocks  17 Clocks	298 KHz	    0	1   1	1   0	1
 | |
| 110 100 7   2	14  16	224 Clocks  33 Clocks	149 KHz	    0	1   0	0   1	1
 | |
| 110 101 7   2	30  32	448 Clocks  65 Clocks	74 KHz	    0	1   1	0   1	1
 | |
| 110 110 7   2	62  64	896 Clocks  129 Clocks	37 KHz	    0	1   0	1   1	1
 | |
| 110 111 7   2	126 128 1792 Clocks 257 Clocks	19 KHz	    0	1   1	1   1	1
 | |
| 111 000 8   2	4   1	26 Clocks   8 Clocks	1282 KHz    1	1   0	0   0	1
 | |
| 111 001 8   2	4   2	40 Clocks   9 Clocks	833 KHz	    1	1   1	0   0	1
 | |
| 111 010 8   2	6   4	72 Clocks   13 Clocks	463 KHz	    1	1   0	1   0	1
 | |
| 111 011 8   2	6   8	128 Clocks  17 Clocks	260 KHz	    1	1   1	1   0	1
 | |
| 111 100 8   2	14  16	256 Clocks  33 Clocks	130 KHz	    1	1   0	0   1	1
 | |
| 111 101 8   2	30  32	512 Clocks  65 Clocks	65 KHz	    1	1   1	0   1	1
 | |
| 111 110 8   2	62  64	1024 Clocks 129 Clocks	33 KHz	    1	1   0	1   1	1
 | |
| 111 111 8   2	126 128 2048 Clocks 257 Clocks	16 KHz	    1	1   1	1   1	1
 | |
| */
 | |
| STATUS SetI2cFDR (PSI2C pi2cRegs, int bitrate)
 | |
| {
 | |
| /* Constants */
 | |
| 	const UINT8 div_hold[8][3] = { {9, 3}, {10, 3},
 | |
| 	{12, 4}, {15, 4},
 | |
| 	{5, 1}, {6, 1},
 | |
| 	{7, 2}, {8, 2}
 | |
| 	};
 | |
| 
 | |
| 	const UINT8 scl_tap[8][2] = { {4, 1}, {4, 2},
 | |
| 	{6, 4}, {6, 8},
 | |
| 	{14, 16}, {30, 32},
 | |
| 	{62, 64}, {126, 128}
 | |
| 	};
 | |
| 
 | |
| 	UINT8 mfdr_bits;
 | |
| 
 | |
| 	int i = 0;
 | |
| 	int j = 0;
 | |
| 
 | |
| 	int Diff, min;
 | |
| 	int WhichFreq, iRec, jRec;
 | |
| 	int SCL_Period;
 | |
| 	int SCL_Hold;
 | |
| 	int I2C_Freq;
 | |
| 
 | |
| 	I2CCDBG (L2, ("Entering getBitRate: bitrate %d pi2cRegs 0x%08x\n",
 | |
| 		      bitrate, (int) pi2cRegs, 0, 0, 0, 0));
 | |
| 
 | |
| 	if (bitrate < 0) {
 | |
| 		I2CCDBG (NO, ("Invalid bitrate\n", 0, 0, 0, 0, 0, 0));
 | |
| 		return ERROR;
 | |
| 	}
 | |
| 
 | |
| 	/* Initialize */
 | |
| 	mfdr_bits = 0;
 | |
| 	min = 0x7fffffff;
 | |
| 	WhichFreq = iRec = jRec = 0;
 | |
| 
 | |
| 	for (i = 0; i < 8; i++) {
 | |
| 		for (j = 0; j < 8; j++) {
 | |
| 			/* SCL Period = 2 * (scl2tap + [(SCL_Tap - 1) * tap2tap] + 2)
 | |
| 			 * SCL Hold   = scl2tap + ((SDA_Tap - 1) * tap2tap) + 3
 | |
| 			 * Bit Rate (I2C Freq) = System Freq / SCL Period
 | |
| 			 */
 | |
| 			SCL_Period =
 | |
| 				2 * (scl_tap[i][0] +
 | |
| 				     ((div_hold[j][0] - 1) * scl_tap[i][1]) +
 | |
| 				     2);
 | |
| 
 | |
| 			/* Now get the I2C Freq */
 | |
| 			I2C_Freq = DEV_CLOCK_FREQ / SCL_Period;
 | |
| 
 | |
| 			/* Take equal or slower */
 | |
| 			if (I2C_Freq > bitrate)
 | |
| 				continue;
 | |
| 
 | |
| 			/* Take the differences */
 | |
| 			Diff = I2C_Freq - bitrate;
 | |
| 
 | |
| 			Diff = ABS (Diff);
 | |
| 
 | |
| 			/* Find the closer value */
 | |
| 			if (Diff < min) {
 | |
| 				min = Diff;
 | |
| 				WhichFreq = I2C_Freq;
 | |
| 				iRec = i;
 | |
| 				jRec = j;
 | |
| 			}
 | |
| 
 | |
| 			I2CCDBG (L2,
 | |
| 				 ("--- (%d,%d) I2C_Freq %d minDiff %d min %d\n",
 | |
| 				  i, j, I2C_Freq, Diff, min, 0));
 | |
| 		}
 | |
| 	}
 | |
| 
 | |
| 	SCL_Period =
 | |
| 		2 * (scl_tap[iRec][0] +
 | |
| 		     ((div_hold[jRec][0] - 1) * scl_tap[iRec][1]) + 2);
 | |
| 
 | |
| 	I2CCDBG (L2, ("\nmin %d WhichFreq %d iRec %d jRec %d\n",
 | |
| 		      min, WhichFreq, iRec, jRec, 0, 0));
 | |
| 	I2CCDBG (L2, ("--- scl2tap %d SCL_Tap %d tap2tap %d\n",
 | |
| 		      scl_tap[iRec][0], div_hold[jRec][0], scl_tap[iRec][1],
 | |
| 		      0, 0, 0));
 | |
| 
 | |
| 	/* This may no require */
 | |
| 	SCL_Hold =
 | |
| 		scl_tap[iRec][0] +
 | |
| 		((div_hold[jRec][1] - 1) * scl_tap[iRec][1]) + 3;
 | |
| 	I2CCDBG (L2,
 | |
| 		 ("--- SCL_Period %d SCL_Hold %d\n", SCL_Period, SCL_Hold, 0,
 | |
| 		  0, 0, 0));
 | |
| 
 | |
| 	I2CCDBG (L2, ("--- mfdr_bits %x\n", mfdr_bits, 0, 0, 0, 0, 0));
 | |
| 
 | |
| 	/* FDR 4,3,2 */
 | |
| 	if ((iRec & 1) == 1)
 | |
| 		mfdr_bits |= 0x04;	/* FDR 2 */
 | |
| 	if ((iRec & 2) == 2)
 | |
| 		mfdr_bits |= 0x08;	/* FDR 3 */
 | |
| 	if ((iRec & 4) == 4)
 | |
| 		mfdr_bits |= 0x10;	/* FDR 4 */
 | |
| 	/* FDR 5,1,0 */
 | |
| 	if ((jRec & 1) == 1)
 | |
| 		mfdr_bits |= 0x01;	/* FDR 0 */
 | |
| 	if ((jRec & 2) == 2)
 | |
| 		mfdr_bits |= 0x02;	/* FDR 1 */
 | |
| 	if ((jRec & 4) == 4)
 | |
| 		mfdr_bits |= 0x20;	/* FDR 5 */
 | |
| 
 | |
| 	I2CCDBG (L2, ("--- mfdr_bits %x\n", mfdr_bits, 0, 0, 0, 0, 0));
 | |
| 
 | |
| 	pi2cRegs->fdr = mfdr_bits;
 | |
| 
 | |
| 	return OK;
 | |
| }
 |