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/** A class for eeprom accesss operation
 *
 *  @author  Poushen Ou
 *  @version 1.0
 *  @date    15-Jun-2018
 *
 *  This code provide classic access operation for I2C EEPROM
 *
 *  About I2C EEPROM 24FC256:
 *      http://ww1.microchip.com/downloads/en/DeviceDoc/21203M.pdf
 */

#include "mbed.h"

#define EEPROM_ADDR 0xA0

/** eeprom Class Library
 * to provide very simple interface for mbed
 *
 * Example:
 * @code
 * #include "mbed.h"
 * #include "eeprom.h"
 *
 * // make eeprom instance using I2C object.
 * // with default slave address 0xA0 (0x50 in 7bit format)
 * // test ok with 24FC256 EEPROM
 * I2C i2c(dp5,dp27);
 * eeprom epm(i2c);
 *
 * int main()
 * {
 *     epm.write_address(12288, TWO_BYTES_ADDRESS);
 * 
 *     for (int i=0; i< 64; i++) {
 *       printf("%.2x ", epm.current_read());
 *     }
 *     printf("\n\r");
 *
 *     while(1);
 * }
 * @endcode
 */
class eeprom
{
public:
    /** Create a eeprom instance connected to specified I2C pins with specified address
     *
     * @param i2c_obj I2C object (instance)
     * @param address (option) I2C-bus slave address (default: 0xA0)
     */
    eeprom(I2C &i2c_obj, char address = EEPROM_ADDR);

    /** Initialization */
    void init(void);
    
    /** Write address with specify address size
     *  
     * @param address eeprom memory address
     * @param address_size should be 1 - 3(ONE_BYTE_ADDRESS, TWO_BYTES_ADDRESS, THREE_BYTES_ADDRESS)
     */
    void write_address(int address, int address_size, bool repeated=false);

    /** Current read, read the current memory data
     *
     * @return the current memory data
     */
    uint8_t current_read(void);
    
    /** Sequential read, read one or many bytes from current memory address
     *
     * @param buffer the start address point to buffer
     * @param buffer_size the length of buffer
     */
    void sequential_read(uint8_t *buffer, int buffer_size);
    
    /** Random read, read one or more memory data from assign memory address
     *
     * @param address eeprom memory address
     * @param address_size should be 1 - 3 (ONE_BYTE_ADDRESS, TWO_BYTES_ADDRESS, THREE_BYTES_ADDRESS)
     * @param buffer the start address point to buffer
     * @param buffer_size the length of buffer
     */
     void random_read(int address, int address_size, uint8_t *buffer, int buffer_size);
     
    /** byte write, write one byte to assign memory address
     *
     * @param address eeprom memory address
     * @param address_size should be 1 - 3(ONE_BYTE_ADDRESS, TWO_BYTES_ADDRESS, THREE_BYTES_ADDRESS)
     * @param data the byte data to write
     */
    void byte_write(int address, int address_size, uint8_t data, bool repeated=false);
    
    /** page write, write many bytes to assign memory address
     * , do not deal with page size and aligned problem, be careful to use!!!
     *
     * @param address eeprom memory address
     * @param address_size should be 1 - 3(ONE_BYTE_ADDRESS, TWO_BYTES_ADDRESS, THREE_BYTES_ADDRESS)
     * @param buffer the page data to write
     */
    void page_write(int address, int address_size, uint8_t *buffer, int buffer_size, bool repeated=false);
    
    /** ack polling, wait for EEPROM write completed */
    void ack_polling(void);

private:
    I2C &i2c;
    char adr;
};

enum {
    ONE_BYTE_ADDRESS = 1,
    TWO_BYTES_ADDRESS,
    THREE_BYTES_ADDRESS
};