/* *********I2c Driver Test Program***************************************
 Program Name:IIC Driver Test Program
 Function:test IIC based MCU writing & reading function
 Designer:Donglei （ICL of Peking Uni.）
 Description:Not using kernel's driver,new driver for MCU read operation test
 Edition:2.0  8_5_08 Moring 
 Problem:
 In addition:
 ***************************************************************************/
#include <linux/mm.h>#include <linux/config.h>
#include <linux/spinlock.h>#include <linux/miscdevice.h>#include <linux/delay.h>
#include <asm/uaccess.h>#include <linux/slab.h>#include <linux/clocks.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/poll.h>
#include <linux/wait.h>
#include <asm/io.h>
#include <linux/interrupt.h>
#include <linux/sched.h>#include <asm/irq.h>
#include <asm/arch/irqs.h>#define bWTCOM(Nb)               __REG(0x53000000+(Nb))
#define WTCON                   bWTCON(0)
#define WTDAT                   bWTCON(4)
#define WTCTN                   bWTCON(8) 
#define VA_IIC_BASE		  io_p2v(0x54000000)
#define S3C_IICCON  	          (VA_IIC_BASE + 0x0)
#define S3C_IICSTAT       	  (VA_IIC_BASE + 0x4)
#define S3C_IICADD        	  (VA_IIC_BASE + 0x8)
#define S3C_IICDS                 (VA_IIC_BASE + 0xc)

#define __REG_B(x)               (*(volatile unsigned char *)(x))
#define IICCON			__REG_B(VA_IIC_BASE + 0x0)
#define IICSTAT			__REG_B(VA_IIC_BASE + 0x4)
#define IICADD			__REG_B(VA_IIC_BASE + 0x8)
#define IICDS			__REG_B(VA_IIC_BASE + 0xc)
#define S3C_IICLC                 (VA_IIC_BASE + 0x10)
#define IICLC			__REG_B(VA_IIC_BASE + 0x10)
#define DEVICE_NAME          "i2c_test"
#define POLLACK     0       //Test ACK signal received or not
#define SETRDADDR   3 #define UNIT         (1000*1000)   //clock transunit define for PCLK
#define HIGHSCALE     0x40      //PCLK's 512 prescale for IICCLK set
#define LOWSCALE      0x00      //PCLK's 16 prescale for IICCLK set

static volatile unsigned long PCLK;   //PC clock
static volatile int iicMode;//Operation mode select flag
static volatile int iicStatus;//IIC status flag
static volatile int NoAckF;//ACK signal get flag
static volatile int iicDataCount;//Data trans Number
static volatile int iicRDTransNum;//The data number of READ transforation
static volatile int iicWRTransNum;//The data number of WRITE transforation
static volatile int delayLoopCount; //for the Delay() function
static volatile int writedataF;    //Write data start flag
static volatile int readdataF;     //Read data start flag

__u16 SaveGPECON;    //For GPECON register save 
__u16 SaveGPEUP;     //For GPEUP register save
__u8 slaveAddr;             //Slave device address
__u8 SCALE_Base;         //Prescale for IICCLK base number
__u8 ConSet;             //The Backup of IICCON set
char *page;                  //IIC device Data buffer
static int IIC_test_open(struct inode *inode,struct file *filp)
{
MOD_INC_USE_COUNT;
return 0;
}
static int IIC_test_release(struct inode *inode,struct file *filp)
{
MOD_DEC_USE_COUNT;
return 0;
}/****************************Delay Function**********************************************/
void Delay(int time)
{
      	// time=0: adjust the Delay function by WatchDog timer.
      	// time>0: the number of loop time
      	// resolution of time is 100us.
 	int i, adjust=0;

    	if(time==0)
    	{
       	time   = 200;
        adjust = 1;
        delayLoopCount = 800;

         //PCLK/1M,Watch-dog disable,1/64,interrupt disable,reset disable
        	WTCON = ((PCLK/1000000-1)<<8)|(2<<3); 
        	WTDAT = 0xffff;                              //for first update
        	WTCNT = 0xffff;                              //resolution=64us @any PCLK 
		WTCON = ((PCLK/1000000-1)<<8)|(2<<3)|(1<<5); //Watch-dog timer start
    	}

    	for(;time>0;time--)
       	for(i=0;i<delayLoopCount;i++);

    	if(adjust==1)
    	{
        	WTCON = ((PCLK/1000000-1)<<8)|(2<<3); //Watch-dog timer stop
        	i = 0xffff - WTCNT;                     //1count->64us, 200*800 cycle runtime = 64*i us

        	delayLoopCount = 16000000/(i*64);         //200*800:64*i=1*x:100 -> x=160000*100/(64*i)   
    	}
    		
}
/****************************i2c bus release(for MasRx & MasTx mode)**********************************/
void ReleaseRXBus(void)
{    IICSTAT=0x90; 
    Delay(1);                        //Wait until stop condtion is in effect.
    //GPECON=SaveGPECON;                 
    //GPEUP=SaveGPEUP;
}
void ReleaseTXBus(void)
{    IICSTAT=0xd0;
    Delay(1);                        //Wait until stop condtion is in effect.
    //GPECON=SaveGPECON;
    //GPEUP=SaveGPEUP;
}

/****************************IRQ serve segment********************************/
static void i2c_isr(int irq,void *dev_id, struct pt_regs *regs)
{    __u32 delayF;
    __u32 iicSt;    int i;
    INTMSK=INTMSK|(0x01<<27);            //Disable IIC interrupts,when ioctl cmd takes effect mask set to 0
    iicSt   = IICSTAT; //When some errors happen wait until the stop condition takes effect
    
    if(iicSt & 0x1)    
    {           NoAckF=1;             //When ACK isn't received
       if((writedataF==1)||(readdataF==1))       
      { 
        NoAckF=0;       }      
    }   
    if(iicMode==POLLACK)            //if interrupt polled out the ack signal the operation will stop test,then into the send data step
           {
           	 if(NoAckF)
            { 
            	 NoAckF =0;
            }        
            else
            {
                 iicStatus = 1;    
            }
          }   
      SRCPND=SRCPND&~(0x1<<27);     //clear pending
      INTPND=INTPND&~(0x1<<27);
      INTMSK = INTMSK&~(0x1<<27);  //open IIC Interrupt
 }
/****************************Initialization segment******************************************************/
static int i2c_Initialization(void) 
{     
	 int ret;   int i;
	 NoAckF = 0;	 writedataF=0;
	 readdataF=0;	/*field protection has fetal problem.If add following 2 statments, system can't wake up the second interrupt. I don't know why.          It needs consideration & experiment*/
	 //SaveGPECON = GPECON;                 //Save the GPE pin settment
         //SaveGPEUP  = GPEUP;                  //Save the GPE pin statment         SRCPND = SRCPND&~(0x01<<27);
	 INTPND = INTPND&~(0x01<<27);
	 INTPND ;
	 INTMSK = INTMSK&~(0x01<<27);
	 free_irq(IRQ_IIC,NULL);         
	    Delay(1);
    	ret = request_irq(IRQ_IIC, i2c_isr, SA_INTERRUPT, "i2c_test", NULL);
        if (ret) 
        {
          printk (KERN_ERR "i2c_test: IRQ %d is already in use.\n",IRQ_IIC);
        }        
        printk("i2c_isr is set!\n");                PCLK=elfin_get_bus_clk(GET_PCLK);        PCLK/=UNIT;                printk("%03ld Mhz\n",PCLK);        
        GPEUP  |= 0xc000;                  //Pull-up disable
        GPECON |= 0xa00000;                //GPE15:IICSDA , GPE14:IICSCL
        
         /**Enable ACK, Prescaler IICCLK=PCLK/16, Enable interrupt, Transmit clock value Tx clock=IICCLK/16
           If PCLK 50.7MHz, IICCLK = 3.17MHz, Tx Clock = 0.198MHz**/
        IICCON = (1<<7) | (1<<5) | (0xf)|SCALE_Base;	//prescaler 16 TCV set
        ConSet=IICCON;
        IICSTAT = 0x10;                    //IIC bus data output enable(Rx/Tx); clear status flag
        IICADD	= 0x00;		           //IIC Master address
        IICLC  = (1<<2)|(1);  	           // Filter enable, 15 clocks SDA output delay
        IICDS = 0x00;	
    printk("Initialized!\n") ;
    return 0;
   
}
/*****************************Read system call for i2c_test*****************************************/
static int i2c_test_read(struct file *filp, const char *buf,size_t count,loff_t *ppos)
{
     int i,j,n;
    __u32 k,m;
    k=0;
    m=0;
    n=0;                              
     iicStatus = 0;
     iicMode = POLLACK;  
     i2c_Initialization();              //Initialization for i2c bus operation
     iicDataCount = 1;
     IICSTAT =0x90;                    //Set MasRx Mode
     IICDS   = slaveAddr;
     IICSTAT = 0xb0;                    //MasTx,Start  
      //Clearing the pending bit isn't needed because the pending bit has been cleared.
     while(iicStatus!=1)   {
     	      if(m==400000)
         {