/****************************************************************************
*   Copyright: (C)2014 Î人ÁèÔÆǶÈëʽʵÑéÊÒ www.emblinux.com
*      Author: GuoWenxue<guowenxue@gmail.com> QQ: 281143292
* Description: ·Ü¶·STM32v5¿ª·¢°åGPIOÄ£ÄâÉãÏñÍ·SCCB(Serial Camera Control Bus)µÄʵÏÖ,
*              SCCBµÄ¹¤×÷·½Ê½ÓëI2CÊ®·ÖÀàËÆ£¬ËûʹÓÃOV¹«Ë¾¶¨ÒåµÄ3Ïß´®ÐÐÉãÏñÍ·¿ØÖÆ×ÜÏߣ¬
*              ¿ÉÒÔ¿ØÖƴ󲿷ÖOVϵÁÐͼÐδ«¸ÐÆ÷¡£SCCBÒ²¿ÉÒÔ¹¤×÷ÔÚ2Ïß´®ÐÐģʽ(SIOCÓëSIOD).
*              STM32ÉÏʹÓÃPE2ºÍPE3·Ö±ðÁ¬½ÓOV7670µÄSCCBʱÖÓ¿ÚºÍÊý¾Ý¿Ú,¸Ã´úÂëÖ÷ҪʹÓÃ
*              PE2ºÍPE3µÄGPIO¿ÚÄ£ÄâSCCB(Ò²¼´I2C)×ÜÏßЭÒé
*
*   ChangeLog:
*        °æ±¾ºÅ     ÈÕÆÚ       ×÷Õß      ˵Ã÷
*        V1.0.0  2014.08.25  GuoWenxue   ·¢²¼¸Ã°æ±¾
****************************************************************************/
/* CF7670C-V3ÉãÏñÍ·Ä£¿éPin¹Ü½ÅºÍSTM32v5 Á¬½Ó±í:
*| ²Î¿¼<CF7670C-V3 ¼òҪ˵Ã÷.pdf>ºÍ<·Ü¶·STM32¿ª·¢°åV5Ô­Àíͼ.pdf>
*+---------------------------------------+------------------------------+
*|   CF7670C-V3ÉãÏñÍ·Ä£¿éÒý½Å¼°ËµÃ÷      |     STM32¶ËÒý½ÅÁ¬½Ó¼°ËµÃ÷    |
*+---------------------------------------+------------------------------+
*| Pin1-VCC(3.3V,·½º¸Å̱ê¼ÇµÄΪµÚÒ»½Å)   |        3.3V                  |
*| Pin2-GND                              |        GND                   |
*| Pin3-SCL(SCCB_SCL²»´øÉÏÀ­µç×è)        |        PE2                   |
*| Pin4-SDA(SCCB_SDA ´ø4.7KÉÏÀ­µç×è)     |        PE3                   |
*| Pin5-VSYNC(OV7670  ֡ͬ²½ÐźÅ)        |        PE4                   |
*| Pin6-HREF(OV7670  ÐÐͬ²½ÐźÅ)         |        NC                    |
*| Pin7-WEN(FIFO(AL422)дÔÊÐí,¸ßµçƽÓÐЧ |        PE5                   |
*| Pin8-XCLK(NC/RE# ¿Õ½Å)                |        NC                    |
*| Pin9-RRST(FIFO¶ÁµØÖ·¸´Î»              |        PE6                   |
*| Pin10-OE#(FIFOÊý¾ÝÊä³öʹÄÜ,µÍµçƽÓÐЧ |        GND                   |
*| Pin11-RCK#(FIFO¶ÁÊý¾ÝʱÖÓ             |        PD12                  |
*| Pin12-GND                             |        GND                   |
*|                                       |                              |
*| Pin13-D0     FIFOÊý¾Ý¿ÚÊä³öBIT0       |        PC0                   |
*| Pin14-D1     FIFOÊý¾Ý¿ÚÊä³öBIT1       |        PC1                   |
*| Pin15-D2     FIFOÊý¾Ý¿ÚÊä³öBIT2       |        PC2                   |
*| Pin16-D3     FIFOÊý¾Ý¿ÚÊä³öBIT3       |        PC3                   |
*| Pin17-D4     FIFOÊý¾Ý¿ÚÊä³öBIT4       |        PC4                   |
*| Pin18-D5     FIFOÊý¾Ý¿ÚÊä³öBIT5       |        PC5                   |
*| Pin19-D6     FIFOÊý¾Ý¿ÚÊä³öBIT6       |        PC6                   |
*| Pin20-D7     FIFOÊý¾Ý¿ÚÊä³öBIT7       |        PC7                   |
*+------------------+-----------------+---------------------------------+
*/

#include "stm32v5_sccb.h"

/* ÅäÖÃÁ¬½ÓOV7670µÄSCCB_SCL(PE2)ºÍSCCB_SDA(PE3)ΪGPIOģʽģÄâ*/
void init_sccb_gpio(void)
{
  GPIO_InitTypeDef  GPIO_InitStructure; 
	
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOE, ENABLE);

  /* Configure I2C pins: PE2->SCL and PE3->SDA */  
  GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_2 ;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode =GPIO_Mode_Out_PP ;//  
  GPIO_Init(GPIOE, &GPIO_InitStructure);
  
  GPIO_InitStructure.GPIO_Pin =   GPIO_Pin_3;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode =  GPIO_Mode_Out_PP ;
  GPIO_Init(GPIOE, &GPIO_InitStructure);
}


/* I2C ×ÜÏßʱÖÓÑÓʱº¯Êý */
static void I2C_delay(void)
{	
   unsigned short i = 200; /* ÕâÀï¿ÉÒÔÓÅ»¯ËÙ¶È */
   while(i) 
   { 
     i--; 
   } 
}


/* I2C×ÜÏß¿ªÊ¼ÐźŠ*/
static int I2C_Start(void)
{
	SDA_H;
	I2C_delay();
	
	SCL_H; 
	I2C_delay();
	
	SDA_L;
	I2C_delay(); 
	
  SCL_L;
	I2C_delay(); 
	
	return ENABLE;
}

/* I2C×ÜÏßÍ£Ö¹ÐźŠ*/
static void I2C_Stop(void)
{
	SDA_L;
	I2C_delay();
	
	SCL_H;
	I2C_delay();
	
	SDA_H;
	I2C_delay();
}

/* I2C×ÜÏßSDAÊäÈë */
 void I2C_IN(void)
{
  GPIO_InitTypeDef  GPIO_InitStructure;   
  
  RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOE, ENABLE);
	
  GPIO_InitStructure.GPIO_Pin =   GPIO_Pin_3; 
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD; //GPIO_Mode_Out_OD;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOE, &GPIO_InitStructure);
}

/* I2C×ÜÏßSDAÊä³ö */
void I2C_OUT(void)
{
  GPIO_InitTypeDef  GPIO_InitStructure; 
	
  GPIO_InitStructure.GPIO_Pin =   GPIO_Pin_3;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_InitStructure.GPIO_Mode =GPIO_Mode_Out_PP ;//  
  GPIO_Init(GPIOE, &GPIO_InitStructure);
}



/* I2C×ÜÏßACKÐźŠ*/
static void I2C_Ack(void)
{	
	SCL_L;
	I2C_delay();
	
	SDA_L;
	I2C_delay();
	
	SCL_H;
	I2C_delay();
	
	SCL_L;
	I2C_delay();
}

/* I2C×ÜÏßNAKÐźŠ*/
static void I2C_NoAck(void)
{	
	SDA_H;
	I2C_delay();
	
	SCL_H;
	I2C_delay();
	
	SCL_L;
	I2C_delay();
	
	SDA_L;
	I2C_delay();
}

/* I2C×ÜÏߵȴýACKÐźŠ*/
static int I2C_WaitAck(void) 	
{
	I2C_IN();
	I2C_delay();
	
	SCL_H;
	I2C_delay();
	
	if(SDA_read)
	{
      SCL_L;
      return DISABLE;
	}
	SCL_L;
	I2C_delay();
	
	I2C_OUT();
	I2C_delay();
	return ENABLE;
}

/* I2C×ÜÏß·¢ËÍÒ»¸ö×Ö½ÚÊý¾Ý, Êý¾Ý´Ó¸ßλµ½µÍλ */
static void I2C_SendByte(uint8_t SendByte) 
{
    uint8_t i=8;
	
    while(i--)
    {
      //SCL_L;
      //I2C_delay();
      if(SendByte&0x80)	
				SDA_H;  
      else
				SDA_L;   			
      SendByte<<=1;
      I2C_delay();
			
	    SCL_H;
      I2C_delay();
			
	    SCL_L;
	    I2C_delay();
    }
}


/* I2C×ÜÏß½ÓÊÕÒ»¸ö×Ö½ÚÊý¾Ý, Êý¾Ý´Ó¸ßλµ½µÍλ */
static int I2C_ReceiveByte(void)  
{ 
    uint8_t i=8;
    uint8_t ReceiveByte=0;

    SDA_H;				
    while(i--)
    {
      ReceiveByte<<=1;      
      SCL_L;
      I2C_delay();
			
			SCL_H;
			I2C_IN();
      I2C_delay();
			
			if(SDA_read)
      {
        ReceiveByte|=0x01;
      } 
    }
		
    SCL_L;
		I2C_OUT();
    return ReceiveByte;
}

/*******************************************************************************
* Function Name  : I2C_WriteByte
* Description    : дһ×Ö½ÚÊý¾Ý
* Input          : - WriteAddress: ´ýдÈëµØÖ·
*           	   - SendByte: ´ýдÈëÊý¾Ý
*                  - DeviceAddress: Æ÷¼þÀàÐÍ
* Output         : None
* Return         : ·µ»ØΪ:=1³É¹¦Ð´Èë,=0ʧ°Ü
* Attention		 : None
*******************************************************************************/           
int I2C_WriteByte( uint16_t WriteAddress , uint8_t SendByte , uint8_t DeviceAddress)
{		
    if(!I2C_Start())
		{
	    return DISABLE;
		}
		I2C_delay();
		
    I2C_SendByte( DeviceAddress );                    /* Æ÷¼þµØÖ· */
    if( !I2C_WaitAck() )
		{
			I2C_Stop(); 
			return DISABLE;
		}
		I2C_delay();
		
    I2C_SendByte((uint8_t)(WriteAddress & 0x00FF));   /* ÉèÖõÍÆðʼµØÖ· */      
    I2C_WaitAck();
		I2C_delay();	
		
    I2C_SendByte(SendByte);
    I2C_WaitAck();
		I2C_delay(); 
		
    I2C_Stop(); 
		I2C_delay();
    return ENABLE;
}									 

/*******************************************************************************
* Function Name  : I2C_ReadByte
* Description    : ¶ÁÈ¡Ò»´®Êý¾Ý
* Input          : - pBuffer: ´æ·Å¶Á³öÊý¾Ý
*           	   - length: ´ý¶Á³ö³¤¶È
*                  - ReadAddress: ´ý¶Á³öµØÖ·
*                  - DeviceAddress: Æ÷¼þÀàÐÍ
* Output         : None
* Return         : ·µ»ØΪ:=1³É¹¦¶ÁÈë,=0ʧ°Ü
* Attention		 : None
*******************************************************************************/          
int I2C_ReadByte(uint8_t* pBuffer,   uint16_t length,   uint8_t ReadAddress,  uint8_t DeviceAddress)
{	
    if(!I2C_Start())
		{
	    return DISABLE;
		}
		
    I2C_SendByte( DeviceAddress );         /* Æ÷¼þµØÖ· */
    if( !I2C_WaitAck() )
		{
			I2C_Stop(); 
			return DISABLE;
		}
		
    I2C_SendByte( ReadAddress );           /* ÉèÖõÍÆðʼµØÖ· */      
    I2C_WaitAck();	
    I2C_Stop(); 
	
    if(!I2C_Start())
		{
			return DISABLE;
		}
    I2C_SendByte( DeviceAddress + 1 );     /* Æ÷¼þµØÖ· */ 

    if(!I2C_WaitAck())
		{
			I2C_Stop(); 
			return DISABLE;
		}
		
    while(length)
    {
      *pBuffer = I2C_ReceiveByte();
      if(length == 1)
			{
				I2C_NoAck();
			}
      else
			{
				I2C_Ack(); 
			}
			
      pBuffer++;
      length--;
    }
		
    I2C_Stop();
    return ENABLE;
}