uint8_t eeprom_read_byte(const uint16_t address) {
/* Start data transmission on the bus. */
eeprom_start();
/* Send a dummy write to the bus with the requested read address. */
eeprom_i2c_write(EEPROM_I2C_WRITE_ADDRESS);
eeprom_i2c_write(address >> 8);
eeprom_i2c_write(address);
/* Start data transmission on the bus. */
eeprom_start();
/* Send to the bus a read request. */
eeprom_i2c_write(EEPROM_I2C_READ_ADDRESS);
/* Read the byte from the EEPROM. */
uint8_t byte = eeprom_i2c_read();
/* Return a NACK for acknowledgement. */
eeprom_i2c_send_ack(EEPROM_I2C_NACK);
/* Stop data transmission on the bus. */
eeprom_stop();
return byte;
}
static void
eeprom_write(int addr, cyg_uint8 val)
{
cyg_uint8 start_byte;
int i;
start_byte = 0xA0; // write
if (addr & (1 << 8))
start_byte |= 2;
for (i = 0; i < 10; i++)
if (eeprom_start(start_byte))
break;
if (i == 10) {
diag_printf("eeprom_write: Can't get start ACK\n");
return;
}
if (!eeprom_putb(addr & 0xff)) {
diag_printf("eeprom_write: Can't get address ACK\n");
return;
}
if (!eeprom_putb(val)) {
diag_printf("eeprom_write: no data ACK\n");
return;
}
eeprom_stop();
}
int eeprom_main(int argc, char *argv[])
{
if (argc >= 2) {
if (!strcmp(argv[1], "start"))
eeprom_start();
if (!strcmp(argv[1], "save_param"))
eeprom_save(argv[2]);
if (!strcmp(argv[1], "load_param"))
eeprom_load(argv[2]);
if (!strcmp(argv[1], "erase"))
eeprom_erase();
if (!strcmp(argv[1], "test"))
eeprom_test();
if (0) { /* these actually require a file on the filesystem... */
if (!strcmp(argv[1], "reformat"))
eeprom_ioctl(FIOC_REFORMAT);
if (!strcmp(argv[1], "repack"))
eeprom_ioctl(FIOC_OPTIMIZE);
}
}
errx(1, "expected a command, try 'start'\n\t'save_param /eeprom/parameters'\n\t'load_param /eeprom/parameters'\n\t'erase'\n");
}
static int
eeprom_read(int addr, cyg_uint8 *buf, int nbytes)
{
cyg_uint8 start_byte;
int i;
start_byte = 0xA0; // write
if (addr & (1 << 8))
start_byte |= 2;
for (i = 0; i < 10; i++)
if (eeprom_start(start_byte))
break;
if (i == 10) {
diag_printf("eeprom_read: Can't get write start ACK\n");
return 0;
}
if (!eeprom_putb(addr & 0xff)) {
diag_printf("eeprom_read: Can't get address ACK\n");
return 0;
}
start_byte |= 1; // READ command
if (!eeprom_start(start_byte)) {
diag_printf("eeprom_read: Can't get read start ACK\n");
return 0;
}
for (i = 0; i < (nbytes - 1); i++)
*buf++ = eeprom_getb(1);
*buf++ = eeprom_getb(0);
hal_delay_us(5);
eeprom_stop();
return nbytes;
}
bool eeprom_write_byte(const uint8_t value, const uint16_t address) {
/* Start data transmission on the bus. */
eeprom_start();
/* Send a write request containing the target address to the bus. */
eeprom_i2c_write(EEPROM_I2C_WRITE_ADDRESS);
eeprom_i2c_write(address >> 8);
eeprom_i2c_write(address);
/* Send the byte to write to the bus. */
eeprom_i2c_write(value);
/* Read the acknowledgement result from the operation. */
bool result = eeprom_i2c_get_ack();
/* Stop data transmission on the bus. */
eeprom_stop();
return result;
}