PiEEPROM.cpp

/*
 * PiEEPROM.cpp - AVR EEPROM like implementation for Raspberry Pi
 *
 * Copyright (C) 2014 Tomas Hozza <thozza@gmail.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 *
 */

#include <stddef.h>
#include <stdint.h>
#include <string.h>

#include <PiEEPROM.h>

#ifdef __cplusplus
extern "C" {
#endif

uint8_t _eeprom[EEPROM_SIZE] = {};

int eeprom_is_ready()
{
    return 1;
}

/**
 * Read one byte from EEPROM address __p.
 */
uint8_t eeprom_read_byte (const uint8_t *__p)
{
    size_t addr = (size_t)__p;

    if (addr < EEPROM_SIZE)
    {
        return *(_eeprom + addr);
    }

    return 0;
}

/**
 * Read one 16-bit word (little endian) from EEPROM address __p.
 */
uint16_t eeprom_read_word (const uint16_t *__p)
{
    size_t addr = (size_t)__p;

    if (addr < EEPROM_SIZE - (sizeof(uint16_t) - sizeof(uint8_t)))
    {
        return (uint16_t)*(_eeprom + addr);
    }

    return 0;
}

/**
 * Read one 32-bit double word (little endian) from EEPROM address __p.
 */
uint32_t eeprom_read_dword (const uint32_t *__p)
{
    size_t addr = (size_t)__p;

    if (addr < EEPROM_SIZE - (sizeof(uint32_t) - sizeof(uint8_t)))
    {
        return (uint32_t)*(_eeprom + addr);
    }

    return 0;
}

/**
 * Read one float value (little endian) from EEPROM address __p.
 */
float eeprom_read_float (const float *__p)
{
    size_t addr = (size_t)__p;

    if (addr < EEPROM_SIZE - (sizeof(float) - sizeof(uint8_t)))
    {
        return (float)*(_eeprom + addr);
    }

    return 0;
}

/**
 * Read a block of __n bytes from EEPROM address __src to SRAM __dst.
 */
void eeprom_read_block (void *__dst, const void *__src, size_t __n)
{
    size_t addr = (size_t)__src;

    if (addr < EEPROM_SIZE - (__n - sizeof(uint8_t)))
    {
        memcpy(__dst, (_eeprom + addr), __n);
    }
}



/**
 * Write a byte __value to EEPROM address __p.
 */
void eeprom_write_byte (uint8_t *__p, uint8_t __value)
{
    size_t addr = (size_t)__p;

    if (addr < EEPROM_SIZE)
    {
        memcpy((_eeprom + addr), &__value, sizeof(uint8_t));
    }
}

/**
 * Write a word __value to EEPROM address __p.
 */
void eeprom_write_word (uint16_t *__p, uint16_t __value)
{
    size_t addr = (size_t)__p;

    if (addr < EEPROM_SIZE - (sizeof(uint16_t) - sizeof(uint8_t)))
    {
        memcpy((_eeprom + addr), &__value, sizeof(uint16_t));
    }
}

/**
 * Write a 32-bit double word __value to EEPROM address __p.
 */
void eeprom_write_dword (uint32_t *__p, uint32_t __value)
{
    size_t addr = (size_t)__p;

    if (addr < EEPROM_SIZE - (sizeof(uint32_t) - sizeof(uint8_t)))
    {
        memcpy((_eeprom + addr), &__value, sizeof(uint32_t));
    }
}

/**
 * Write a float __value to EEPROM address __p.
 */
void eeprom_write_float (float *__p, float __value)
{
    size_t addr = (size_t)__p;

    if (addr < EEPROM_SIZE - (sizeof(float) - sizeof(uint8_t)))
    {
        memcpy((_eeprom + addr), &__value, sizeof(float));
    }
}

/**
 * Write a block of __n bytes to EEPROM address __dst from __src.
 * The argument order is mismatch with common functions like strcpy().
 */
void eeprom_write_block (const void *__src, void *__dst, size_t __n)
{
    size_t addr = (size_t)__dst;

    if (addr < EEPROM_SIZE - (__n - sizeof(uint8_t)))
    {
        memcpy((_eeprom + addr), __src, __n);
    }
}


#ifdef __cplusplus
}
#endif