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/******************************************************************************
*
* Filename: eeprom.c
*
* Instantiation of eeprom routines
*
* Revision information:
*
* 28AUG2004 kb_admin initial creation - adapted from Atmel sources
* 12JAN2005 kb_admin fixed clock generation, write polling, init
*
* 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
*
* $FreeBSD$
*****************************************************************************/
#include "at91rm9200_lowlevel.h"
#include "at91rm9200.h"
#include "lib.h"
/******************************* GLOBALS *************************************/
/*********************** PRIVATE FUNCTIONS/DATA ******************************/
/* Use a macro to calculate the TWI clock generator value to save code space. */
#define AT91C_TWSI_CLOCK 100000
#define TWSI_EEPROM_ADDRESS 0x50
#define TWI_CLK_BASE_DIV ((AT91C_MASTER_CLOCK/(4*AT91C_TWSI_CLOCK)) - 2)
#define SET_TWI_CLOCK ((0x00010000) | (TWI_CLK_BASE_DIV) | (TWI_CLK_BASE_DIV << 8))
/*************************** GLOBAL FUNCTIONS ********************************/
/*
* .KB_C_FN_DEFINITION_START
* void InitEEPROM(void)
* This global function initializes the EEPROM interface (TWI). Intended
* to be called a single time.
* .KB_C_FN_DEFINITION_END
*/
void
InitEEPROM(void)
{
AT91PS_TWI twiPtr = (AT91PS_TWI)AT91C_BASE_TWI;
AT91PS_PIO pPio = (AT91PS_PIO)AT91C_BASE_PIOA;
AT91PS_PMC pPMC = (AT91PS_PMC)AT91C_BASE_PMC;
pPio->PIO_ASR = AT91C_PA25_TWD | AT91C_PA26_TWCK;
pPio->PIO_PDR = AT91C_PA25_TWD | AT91C_PA26_TWCK;
pPio->PIO_MDDR = ~AT91C_PA25_TWD;
pPio->PIO_MDER = AT91C_PA25_TWD;
pPMC->PMC_PCER = 1u << AT91C_ID_TWI;
twiPtr->TWI_IDR = 0xffffffffu;
twiPtr->TWI_CR = AT91C_TWI_SWRST;
twiPtr->TWI_CR = AT91C_TWI_MSEN | AT91C_TWI_SVDIS;
twiPtr->TWI_CWGR = SET_TWI_CLOCK;
}
/*
* .KB_C_FN_DEFINITION_START
* void ReadEEPROM(unsigned ee_addr, char *data_addr, unsigned size)
* This global function reads data from the eeprom at ee_addr storing data
* to data_addr for size bytes. Assume the TWI has been initialized.
* This function does not utilize the page read mode to simplify the code.
* .KB_C_FN_DEFINITION_END
*/
int
ReadEEPROM(unsigned ee_off, char *data_addr, unsigned size)
{
const AT91PS_TWI twiPtr = AT91C_BASE_TWI;
unsigned int status;
unsigned int count;
status = twiPtr->TWI_SR;
status = twiPtr->TWI_RHR;
// 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_off;
// Start transfer
twiPtr->TWI_CR = AT91C_TWI_START;
status = twiPtr->TWI_SR;
while (size-- > 1){
// Wait RHR Holding register is full
count = 1000000;
while (!(twiPtr->TWI_SR & AT91C_TWI_RXRDY) && --count > 0)
continue;
if (count <= 0)
return -1;
// Read byte
*(data_addr++) = twiPtr->TWI_RHR;
}
twiPtr->TWI_CR = AT91C_TWI_STOP;
status = twiPtr->TWI_SR;
// Wait transfer is finished
while (!(twiPtr->TWI_SR & AT91C_TWI_TXCOMP))
continue;
// Read last byte
*data_addr = twiPtr->TWI_RHR;
return 0;
}
/*
* .KB_C_FN_DEFINITION_START
* void WriteEEPROM(unsigned ee_off, char *data_addr, unsigned size)
* This global function writes data to the eeprom at ee_off using data
* from data_addr for size bytes. Assume the TWI has been initialized.
* This function does not utilize the page write mode as the write time is
* much greater than the time required to access the device for byte-write
* functionality. This allows the function to be much simpler.
* .KB_C_FN_DEFINITION_END
*/
void
WriteEEPROM(unsigned ee_off, char *data_addr, unsigned size)
{
const AT91PS_TWI twiPtr = AT91C_BASE_TWI;
unsigned status;
char test_data;
while (size--) {
if (!(ee_off & 0x3f))
putchar('.');
// 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_off++;
status = twiPtr->TWI_SR;
twiPtr->TWI_THR = *(data_addr++);
twiPtr->TWI_CR = AT91C_TWI_START;
// Wait transfer is finished
while (!(twiPtr->TWI_SR & AT91C_TWI_TXRDY))
continue;
twiPtr->TWI_CR = AT91C_TWI_STOP;
status = twiPtr->TWI_SR;
// Wait transfer is finished
while (!(twiPtr->TWI_SR & AT91C_TWI_TXCOMP))
continue;
// wait for write operation to complete
ReadEEPROM(ee_off, &test_data, 1);
}
putchar('\r');
putchar('\n');
}
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