rr_i2c.c

针对德州仪器DM270开发板的bootloader,其实现了内核的下载以及文件系统的下载

/***************************************************************/
/*     i2c for PMU(PCF50606) control                           */
/*     Date : 2004. 03. 16					                   */
/*     Version : 0.1                                           */
/*     Reigncom Ltd.		                                   */		
/*						                                       */
/***************************************************************/
									
#include "i2c.h"

//==========    Definitions   =================

#define REG	*(volatile unsigned short *)
#define OSEL	0x3089A
#define O0DIV	0x3089C
#define O1DIV	0x3089E
#define PWM0C	0x308A2
#define PWM0H	0x308A4
#define PWM1C	0x308A6
#define PWM1H	0x308A8
#define BITSET_BASE		0x3058C
#define BITCLR_BASE		0x30592
#define DIR_BASE	0x30580


void GIODirSet(unsigned char port, unsigned char dir){                                                 
    unsigned char gio_offset = 0;                                                                      
    
    while(port > 15){        
        port -= 16; 
        gio_offset +=2;  
    }

    if(dir)         
        REG (DIR_BASE + gio_offset) |= (1 << port);                                                    
    else            
        REG (DIR_BASE + gio_offset) &= ~(1 << port);                                                   
}


void GIOSet(unsigned char port,unsigned char set){
    unsigned char gio_offset = 0;                                                                      

    while(port > 15){        
        port -= 16; 
        gio_offset +=2;  
    }               

    if(set)         
        REG (BITSET_BASE + gio_offset) = (1 << port);                                                  
    else            
        REG (BITCLR_BASE + gio_offset) = (1 << port);                                                  
}

unsigned char GIOGet(unsigned char port){
	unsigned char gio_offset = 0;
	unsigned short temp;
	unsigned char res;

	while(port > 15){
		port -= 16;
		gio_offset += 2;
	}
	
	temp = REG (BITSET_BASE + gio_offset);
	res = temp & (1 << port);

	if(res)
		return(1);
	else
		return(0);
}

void set_PMU_SCL_High(void){
//   REG BITSET1 = PMU_SCL_GIO;
	GIOSet(PMU_SCL_GIO,1);
}

void set_PMU_SCL_Low(void){
   // REG BITCLR1 = PMU_SCL_GIO;
	GIOSet(PMU_SCL_GIO,0);
}

void set_PMU_SDA_High(void){
  //  REG BITSET1 = PMU_SDA_GIO;
	GIOSet(PMU_SDA_GIO,1);
}

void set_PMU_SDA_Low(void){
  //  REG BITCLR1 = PMU_SDA_GIO;
	GIOSet(PMU_SDA_GIO,0);
}

void make_PMU_SDA_Input(void){
//	GIODirSet(PMU_SDA_GIO,1);
	REG 0x30584 |= (0x1);
}

void make_PMU_SDA_Output(void){
//	GIODirSet(PMU_SDA_GIO,0);
	REG 0x30584 &= ~(0x1);
}

unsigned char get_SDA(void){
	volatile unsigned char temp;
	i2c_wait();
	make_PMU_SDA_Input();
	i2c_wait();
	set_PMU_SCL_High();
	i2c_wait();
	i2c_wait();
	i2c_wait();
	i2c_wait();
	i2c_wait();
	temp  = GIOGet(PMU_SDA_GIO);
	set_PMU_SCL_Low();
	i2c_wait();
	i2c_wait();
	i2c_wait();
	if(temp)
		return(1);
	else
		return(0);
}

unsigned char get_Ack(void){

	volatile unsigned char res=0;
	res = get_SDA();
	make_PMU_SDA_Output();

	if(!(res & 0x1))
		return(1);
	else
		return(0); 

}

void send_Ack(void){
	GIOSet(PMU_SDA_GIO,0);
}

void send_Nack(void){
	GIOSet(PMU_SDA_GIO,1);
}

void i2c_wait(void){
	unsigned char i;
	for(i=0;i<200;i++)
		;
}

void i2c_Init(void){
	set_PMU_SCL_High();
	set_PMU_SDA_High();
	GIODirSet(PMU_SCL_GIO,0); //dedicated gio output.
	GIODirSet(PMU_SDA_GIO,0); //dedicated gio output.
	i2c_wait();

	i2c_Open();
	i2c_wait();
}

void i2c_Open(void){
	set_PMU_SDA_Low();
	i2c_wait();
	set_PMU_SCL_Low();
}

void i2c_Stop(void){
	set_PMU_SDA_Low();
	set_PMU_SCL_High();
	i2c_wait();
	set_PMU_SDA_High();
}

int i2c_Send_Byte(unsigned char buff){
    int j=8;

    while(j--){
		i2c_wait();

       if(buff & (0x1 << j)){
           set_PMU_SDA_High();
       }else{
           set_PMU_SDA_Low();
	  }
		i2c_wait();
       set_PMU_SCL_High();
		i2c_wait();
		set_PMU_SCL_Low();
    }

	return 0;
}

unsigned char i2c_Read_Byte(void){
	int i =8;
	volatile unsigned char temp,res= 0;

	while(i--){
		temp = get_SDA();
		res |= (temp << i);
		i2c_wait();
	}
	return res;
}

void i2c_writeReg(unsigned char devaddr, unsigned char subaddr,
					unsigned char value, unsigned char *successflag)
{
	unsigned char flag=1;
	
	i2c_Init();
	i2c_Send_Byte(devaddr & 0xfe); //device write addr...
	flag &= get_Ack(); 

	i2c_Send_Byte(subaddr);
	flag &= get_Ack();

	i2c_Send_Byte(value);
	flag &= get_Ack();

	i2c_Stop();

	*successflag = (flag)? 0 : 1;
}

unsigned char i2c_readReg(unsigned char devaddr, unsigned char subaddr,
						unsigned char *successflag)
{
	unsigned char val,flag = 1;

	i2c_Init();
	i2c_Send_Byte(devaddr & 0xfe);
	flag &= get_Ack();

	i2c_Send_Byte(subaddr);
	flag &= get_Ack();

	i2c_Init();
	i2c_Send_Byte(devaddr |= 0x01);
	flag &= get_Ack();

	i2c_wait();
	val = i2c_Read_Byte();

	make_PMU_SDA_Output();
	i2c_wait();
	send_Nack();
	i2c_Stop();

	*successflag = (flag)? 0 : 1;
	return(val);

}