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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: src/sys/boot/arm/at91/bootspi/ee.c,v 1.1.8.1 2009/04/15 03:14:26 kensmith Exp $
*****************************************************************************/
#include "at91rm9200_lowlevel.h"
#include "at91rm9200.h"
#include "lib.h"
#include "ee.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 0x40
#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
EEInit(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;
}
static inline unsigned
iicaddr(unsigned ee_off)
{
return (TWSI_EEPROM_ADDRESS | ((ee_off >> 8) & 0x7));
}
/*
* .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
*/
void
EERead(unsigned ee_off, char *data_addr, unsigned size)
{
const AT91PS_TWI twiPtr = AT91C_BASE_TWI;
unsigned int status;
if ((ee_off & ~0xff) != ((ee_off + size) & ~0xff)) {
printf("Crosses page boundary: 0x%x 0x%x\n", ee_off, size);
return;
}
status = twiPtr->TWI_SR;
status = twiPtr->TWI_RHR;
twiPtr->TWI_MMR = (iicaddr(ee_off) << 16) | AT91C_TWI_IADRSZ_1_BYTE |
AT91C_TWI_MREAD;
twiPtr->TWI_IADR = ee_off & 0xff;
twiPtr->TWI_CR = AT91C_TWI_START;
while (size-- > 1) {
while (!(twiPtr->TWI_SR & AT91C_TWI_RXRDY))
continue;
*(data_addr++) = twiPtr->TWI_RHR;
}
twiPtr->TWI_CR = AT91C_TWI_STOP;
status = twiPtr->TWI_SR;
while (!(twiPtr->TWI_SR & AT91C_TWI_TXCOMP))
continue;
*data_addr = twiPtr->TWI_RHR;
}
/*
* .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
EEWrite(unsigned ee_off, const char *data_addr, unsigned size)
{
const AT91PS_TWI twiPtr = AT91C_BASE_TWI;
unsigned status;
char test_data;
while (size--) {
// Set the TWI Master Mode Register
twiPtr->TWI_MMR = (iicaddr(ee_off) << 16) |
AT91C_TWI_IADRSZ_1_BYTE;
twiPtr->TWI_IADR = ee_off++;
status = twiPtr->TWI_SR;
// Load one data byte
twiPtr->TWI_THR = *(data_addr++);
twiPtr->TWI_CR = AT91C_TWI_START;
while (!(twiPtr->TWI_SR & AT91C_TWI_TXRDY))
continue;
twiPtr->TWI_CR = AT91C_TWI_STOP;
status = twiPtr->TWI_SR;
while (!(twiPtr->TWI_SR & AT91C_TWI_TXCOMP))
continue;
// wait for write operation to complete, it is done once
// we can read it back...
EERead(ee_off, &test_data, 1);
}
}
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