diff options
Diffstat (limited to 'sys/boot/arm/at91/bootspi/ee.c')
| -rw-r--r-- | sys/boot/arm/at91/bootspi/ee.c | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/sys/boot/arm/at91/bootspi/ee.c b/sys/boot/arm/at91/bootspi/ee.c new file mode 100644 index 000000000000..62a02d98edfd --- /dev/null +++ b/sys/boot/arm/at91/bootspi/ee.c @@ -0,0 +1,160 @@ +/****************************************************************************** + * + * 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" +#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); + } +} |