#define I2C_Set1(i2c) GPIO_SetBits(i2c);I2C_Delay(5);
#define I2C_Set0(i2c) GPIO_ResetBits(i2c);I2C_Delay(5);
#define I2C_Get(i2c) GPIO_ReadInputBit(i2c);

VOID DRV_I2C_Start(VOID)
{
    I2C_SetOutput(I2C_SDA);
    I2C_Set1(I2C_SDA);
    I2C_Set1(I2C_SCL);
    I2C_Set0(I2C_SDA);
    I2C_Set0(I2C_SCL);
}

VOID DRV_I2C_Stop(VOID)
{
    I2C_SetOutput(I2C_SDA);
    I2C_Set0(I2C_SDA);
    I2C_Set1(I2C_SCL);
    I2C_Set1(I2C_SDA);
}


U32 DRV_I2C_WriteByte(IN U8 data)
{
    U8 i = 0;
    U8 byte = data;
    U8 sda = 0;
    
    I2C_SetOutput(I2C_SDA);
        
    for (i = 0; i < 8; i++)
    {
        I2C_Set0(I2C_SCL);
        if (byte & 0x80)
        {
            I2C_Set1(I2C_SDA);
        }
        else
        {
            I2C_Set0(I2C_SDA);
        }
        I2C_Set1(I2C_SCL);
        byte <<= 1;
    }
    
    I2C_Set0(I2C_SCL);
    I2C_SetInput(I2C_SDA);
    I2C_Set1(I2C_SCL);

    sda = I2C_Get(I2C_SDA);
    if (sda)
    {
        I2C_Set0(I2C_SCL);
        I2C_SetOutput(I2C_SDA);
        return OS_ERROR;
    }
    
    I2C_Set0(I2C_SCL);
    I2C_SetOutput(I2C_SDA);
    I2C_Set1(I2C_SDA);
    
    return OS_OK;
}

U32 DRV_I2C_ReadByte(OUT U8 *byte)
{
    U8 i = 0;
    U8 bit = 0;
    U8 sda = 0;

    I2C_SetInput(I2C_SDA);
    
    for (i = 0; i < 8; i++)
    {
        I2C_Set1(I2C_SCL);
        sda = I2C_Get(I2C_SDA);
        if (sda)
        {
            bit |= 0x1;
        }
        I2C_Set0(I2C_SCL);
        if (i != 7)
        {
            bit <<= 1;
        }
    }
    *byte = bit;
    return OS_OK;
}

VOID DRV_I2C_NoAck(VOID)
{
    I2C_Set0(I2C_SCL);
    I2C_SetOutput(I2C_SDA);
    I2C_Set1(I2C_SDA);
    I2C_Set1(I2C_SCL);
    I2C_Set0(I2C_SCL);
}

VOID DRV_I2C_Ack(VOID)
{
    I2C_Set0(I2C_SCL);
    I2C_SetOutput(I2C_SDA);
    I2C_Set0(I2C_SDA);
    I2C_Set1(I2C_SCL);
    I2C_Set0(I2C_SCL);
}

VOID DRV_I2C_Init(VOID)
{
    GPIO_InitPara GPIO_InitStructure;

    RCC_APB2PeriphClock_Enable(RCC_APB2PERIPH_GPIOB,ENABLE);

    GPIO_InitStructure.GPIO_Pin =  GPIO_PIN_6 | GPIO_PIN_7;
    GPIO_InitStructure.GPIO_Mode = GPIO_MODE_OUT_OD;
    GPIO_InitStructure.GPIO_Speed = GPIO_SPEED_50MHZ;
    GPIO_Init(GPIOB, &GPIO_InitStructure);
    GPIO_SetBits(GPIOB, GPIO_PIN_6);
    GPIO_SetBits(GPIOB, GPIO_PIN_7);
}

/* 字节写 */
VOID DRV_AT24C02C_WriteByte(IN U8 slaveAddr, IN U8 byteAddr, IN U8 data)
{
    DRV_I2C_Start();
    DRV_I2C_WriteByte(slaveAddr);
    DRV_I2C_WriteByte(byteAddr);
    DRV_I2C_WriteByte(data);
    DRV_I2C_Stop();
}

/* 页写 */
VOID DRV_AT24C02C_WritePage(IN U8 slaveAddr, IN U8 byteAddr, IN U8 data[], IN U8 len)
{
    U8 i = 0; 
    
    DRV_I2C_Start();
    DRV_I2C_WriteByte(slaveAddr);
    DRV_I2C_WriteByte(byteAddr);
    for (i = 0; i < len; i++)
    {
        DRV_I2C_WriteByte(data[i]);
    }
    DRV_I2C_Stop();
}

/* 选择地址读 */
VOID DRV_AT24C02C_ReadByte(IN U8 slaveAddr, IN U8 byteAddr, OUT U8 *data)
{
    U8 tmp = 0; 

    DRV_I2C_Start();
    DRV_I2C_WriteByte(slaveAddr);
    DRV_I2C_WriteByte(byteAddr);
    DRV_I2C_Start();
    DRV_I2C_WriteByte(slaveAddr+1);
    DRV_I2C_ReadByte(&tmp);
    DRV_I2C_NoAck();    
    DRV_I2C_Stop(); 
    *data = tmp;
}

/* 连续读 */
VOID DRV_AT24C02C_ReadPage(IN U8 slaveAddr, IN U8 byteAddr, OUT U8 data[], IN U8 len)
{
    U8 tmp = 0; 
    U8 i = 0;

    DRV_I2C_Start();
    DRV_I2C_WriteByte(slaveAddr);
    DRV_I2C_WriteByte(byteAddr);
    DRV_I2C_Start();
    DRV_I2C_WriteByte(slaveAddr+1);
    for (i = 0; i < len-1; i++)
    {
        DRV_I2C_ReadByte(&tmp);
        DRV_I2C_Ack();
        data[i] = tmp;
    }
    
    DRV_I2C_ReadByte(&tmp);
    DRV_I2C_NoAck();    
    data[i] = tmp;
    DRV_I2C_Stop();    
}

VOID DRV_AT24C02C_Init(VOID)
{
    DRV_I2C_Init();
}