eeprom.c

linux下ROMMONITOR,FLASH,MODEM等操作原代码,请需要的朋友下载

/*******************************************************************************
 *
 * Filename: eeprom.c
 *
 * Instantiation of eeprom routines
 *
 * Revision information:
 *
 * 28AUG2004	kb_admin	initial creation - adapted from Atmel sources
 *
 * BEGIN_KBDD_BLOCK
 * No warranty, expressed or implied, is included with this software.  It is
 * provided "AS IS" and no warranty of any kind including statutory or aspects
 * relating to merchantability or fitness for any purpose is provided.  All
 * intellectual property rights of others is maintained with the respective
 * owners.  This software is not copyrighted and is intended for reference
 * only.
 * END_BLOCK
 ******************************************************************************/

#include "at91rm9200_lowlevel.h"
#include "eeprom.h"
#include "AT91RM9200.h"

/* ****************************** GLOBALS *************************************/


/* ********************** PRIVATE FUNCTIONS/DATA ******************************/


/* Use a macro to calculate the TWI clock generator value to save code space. */
#define TWI_CLK_BASE_DIV	((AT91C_MASTER_CLOCK/(2*AT91C_TWSI_CLOCK)) - 2)
#define SET_TWI_CLOCK	((0x0001000) | (TWI_CLK_BASE_DIV) | (TWI_CLK_BASE_DIV << 8))

/*
 * .KB_C_FN_DEFINITION_START
 * void SetTWIClock(const AT91PS_TWI twiPtr)
 *  This private function configures the clock used in TWI transactions.
 * .KB_C_FN_DEFINITION_END
 */
static void SetTWIClock(const AT91PS_TWI twiPtr) {

	twiPtr->TWI_CWGR = SET_TWI_CLOCK;
}


/* ************************** GLOBAL FUNCTIONS ********************************/


/*
 * .KB_C_FN_DEFINITION_START
 * void WriteEEPROM(unsigned ee_addr, char *data_addr, unsigned size)
 *  This global function writes data to the eeprom at ee_addr using data
 * from data_addr for size bytes.
 * .KB_C_FN_DEFINITION_END
 */
void WriteEEPROM(unsigned ee_addr, char *data_addr, unsigned size) {

	static unsigned		initialized = 0;
	const AT91PS_TWI 	twiPtr = AT91C_BASE_TWI;
	unsigned		status, useLength;

	if (!initialized) {
		AT91PS_PIO pPio = (AT91PS_PIO)AT91C_BASE_PIOA;
		AT91PS_PMC pPMC = (AT91PS_PMC)AT91C_BASE_PMC;

		initialized = 1;

		pPio->PIO_ASR =
			((unsigned)AT91C_PA25_TWD) | ((unsigned)AT91C_PA26_TWCK);
		pPio->PIO_BSR = 0;
		pPio->PIO_PDR =
			((unsigned)AT91C_PA25_TWD) | ((unsigned)AT91C_PA26_TWCK);

		pPio->PIO_MDDR = ~((unsigned)AT91C_PA25_TWD);
		pPio->PIO_MDER = (unsigned)AT91C_PA25_TWD;

		pPMC->PMC_PCER = ((unsigned) 1 << AT91C_ID_TWI);

		twiPtr->TWI_IDR = (unsigned) -1;
		twiPtr->TWI_CR = AT91C_TWI_SWRST;
		twiPtr->TWI_CR = AT91C_TWI_MSEN | AT91C_TWI_SVDIS;

		SetTWIClock(AT91C_BASE_TWI);
	}

	while (size) {
		DebugPrint(".");

		useLength = ee_addr & (EEPROM_PAGE_SIZE - 1);
		useLength = EEPROM_PAGE_SIZE - useLength;

		if (useLength > size)
			useLength = size;
		size -= useLength;

		// Set the TWI Master Mode Register
		twiPtr->TWI_MMR = ((TWSI_EEPROM_ADDRESS << 16) | AT91C_TWI_IADRSZ_2_BYTE ) & ~AT91C_TWI_MREAD;

		// Set TWI Internal Address Register
		twiPtr->TWI_IADR = ee_addr;
		ee_addr += useLength;

		status = twiPtr->TWI_SR;

		twiPtr->TWI_THR = *(data_addr++);

		twiPtr->TWI_CR = AT91C_TWI_START;

		while (useLength-- > 1) {
			// Wait THR Holding register to be empty
			while (!(twiPtr->TWI_SR & AT91C_TWI_TXRDY));

			// Send first byte
			twiPtr->TWI_THR = *(data_addr++);
		}

		twiPtr->TWI_CR = AT91C_TWI_STOP;		

		status = twiPtr->TWI_SR;

		// Wait transfer is finished
		while (!(twiPtr->TWI_SR & AT91C_TWI_TXCOMP));

		// delay loop - could convert to ack polling method
		for (useLength = 100000; useLength; useLength--);
	}

	DebugPrint("\n\r");
}