apb_i2c_module.c

这个代码是基于JADE X90+ wm8976 的 ALSA标准接口的驱动

/********************************************/
/* I2CFunc.c: implementation of the I2C API.*/
/* Author   : DQ							*/
/* Time     : 2005-12-15					*/
/********************************************/


#include <linux/major.h>
#include <linux/vmalloc.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/bitops.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <asm/io.h>

#include <asm/arch-x900/apb_i2c_module.h>
#include <asm/arch-x900/apb_i2c_tvin.h>


#ifdef CONFIG_ARCH_X900
	 #define PHY_SYS_BASE    0x20031000
	 #define PHY_I2C_BASE    0x20026000
#else
	#define PHY_SYS_BASE	0x20020000
	#define	PHY_I2C_BASE	     0x20036000
#endif

#define SZ_4K           0x1000

unsigned int *g_i2c_base = 0;
unsigned int *g_sysctrl_base = 0;

/* This struct aims at translate parameters.
** Para : addr , the slave's address
** Para : control, the control register's value
** Para : mask, the mask for interrupt
** Para : rx , the recive FIFO's depth
** Para : tx , the transmit FIFO's depth 
**/

typedef struct 
{
	unsigned short addr;
	unsigned short control;
	unsigned short mask;
	unsigned short rx;
	unsigned short tx;
}i2cConfig;

/* This struct describe the SCL Paramter 
** mode : this is the I2C translate mode , such as SS = SlowSpeed, FS = Full Speed , HS = High Speed
** hcnt : this is the High period for the SCL
** lcnt : this is the Low period for the SCL
**/

typedef struct 
{
	I2CMODE mode;
	unsigned short hcnt;
	unsigned short lcnt;
}i2cSpeedMode;


void i2cSetConfig(i2cConfig* Init_data, i2cSpeedMode* m )
{
	I2C_DISABLE;

	if(Init_data)
	{
		I2C_SAR(Init_data->addr);//Set the address of the i2c device
		I2C_CON(Init_data->control);//Set the control register for the transfer
	    I2C_INTR_MASK(Init_data->mask);//Enable interrupts
		I2C_RX_TL(Init_data->rx);//Set Rx FIFO Threshold 
	    I2C_TX_TL(Init_data->tx);//Set Tx FIFO Threshold
    }

	if(m)
	{
		switch(m->mode)
		{
		case I2C_SS:
			I2C_SS_HCNT(m->hcnt);
			I2C_SS_LCNT(m->lcnt);
			break;
		case I2C_FS:
			I2C_FS_HCNT(m->hcnt);
			I2C_FS_LCNT(m->lcnt);
			break;
		case I2C_HS:
			I2C_HS_HCNT(m->hcnt);
			I2C_HS_LCNT(m->lcnt);
			break;	
		default:
			{
				I2C_ERROR("There is no such I2C mode.");
				break;
			}
		}
	}
	
	I2C_ENABLE;//Enable the I2C MASTER

}

void i2cSetTarget( char target_addr)
{
	//Disable the I2C MASTER, all the config should be set when the i2c master is disabled
    if (target_addr)
    {
    	I2C_DISABLE;
	    I2C_TAR(target_addr/2);//Set the address for the target slave
		I2C_ENABLE;//Enable the I2C MASTER
	}
}

/* brief : Initialize the I2C module */
i2cInst* init_i2c()
{
	int error = 0;
	i2cInst* t = 0;	
	i2cConfig* g_initData = 0;
	i2cSpeedMode* spemode = 0;
	// Define the Initialize parameters 
	
	t = (i2cInst*)vmalloc( sizeof(i2cInst));
	if( t )
	{
		t->config = (void*)vmalloc( sizeof(i2cConfig) );
		t->speed = (void*)vmalloc( sizeof(i2cSpeedMode) );
	}
	else
		error = 1;
	
	g_initData = (i2cConfig*)t->config;
	spemode = (i2cSpeedMode*)t->speed;

	g_initData->addr = 0x0045;//slave address
	g_initData->control = 0x0023;//change from 0x0003    /* Ruskee: Why change from 0x03?*/
	g_initData->mask = 0x0000;
	g_initData->rx = 0x0008;  /*Ruskee: Why change from 0x0*/
	g_initData->tx = 0x0000;

	spemode->mode = I2C_SS;
	spemode->hcnt = 0x0028;//0x88; 
	spemode->lcnt = 0x002f;//0x8f;

	g_i2c_base = (u32 *)(ioremap(PHY_I2C_BASE, SZ_4K));
	
	i2cSetConfig(g_initData,spemode);

	return t;
}

/* brief : Delete the I2C module from the system */
void dele_i2c(i2cInst* t)
{
	if(t)
	{
		if(t->config)
			vfree(t->config);
		if(t->speed)
			vfree(t->speed);
		vfree(t);
	}
	iounmap(g_i2c_base);
}

// wait for Receive FIFO Not Empty
int waitRFNE(unsigned int timeout)
{
	timeout = timeout*10000;
	while(!(I2C_STATUS & RFNE)&&timeout)
	{
		timeout --;
	}
	if( timeout > 0 )
		return 0;
	else
		return -1;
}

// Transmit FIFO Not Full
bool isTFNF(void)
{
	if (I2C_STATUS & TFNF)
	   return true;
	else
	   return false;
}

// wait for Transmit FIFO Completely Empty
int waitTFE(unsigned int timeout)
{
	timeout = timeout*10000;
	while(!(I2C_STATUS & TFE)&&timeout)
	{
		timeout --;
	}
	if( timeout > 0 )
		return 0;
	else
		return -1;
}

/* brief: This API is used to transmit data 
** para : threhold -- the  threhold of the FIFO
** para : buffer -- the pointer of data
** para : target -- the address of the target
*/ 
int transmitData(const int threhold, const unsigned char buffer[], const unsigned short target)
{
	int error = 0 ,i;
	
	if(!g_i2c_base)
		return -1;
	
	if(threhold < 0 || threhold >255){
		error = 1;
		return error;
	}
	
	I2C_DISABLE;
	
	I2C_TX_TL((threhold-1));
	I2C_TAR(target);			
	I2C_ENABLE;
	error = waitTFE(100);	
	i=0;
	while(i < threhold)
	{
	   while (!isTFNF());
		I2C_WRITE (buffer[i++]);
		{
			int k = 4;
			while( k -- );
		}
	}	
	error = waitTFE(100);
	udelay(100);
	//hw_delay(1);
	return error;
}


int ReadData(const int threhold, const unsigned char buffer[], const unsigned short target , unsigned char buffer2[])
{
	int i, error = 0,tx_num = threhold;

	if(!g_i2c_base)
	{
		return -1;
	}

	I2C_DISABLE;

	I2C_TX_TL((1));
	I2C_TAR(target);			
   I2C_CON(I2CR_CON | 0x20);

	I2C_ENABLE;
	
	error = waitTFE(100);
	i=0;
	while(i < threhold)
	{
		I2C_WRITE (buffer[i++]);
		{
			int k = 4;
			while( k -- );
		}
	}
	i = 0;
	while( i < threhold && !error)
	{	
		while(((I2C_STATUS)&(TFNF))&&tx_num)
		{
			I2C_WRITE(0x100);	
			tx_num--;
		}
		error = waitRFNE(100);
		buffer2[ i ] = I2C_READ;
		i++;
	}
	return error;
}

int i2cWrite( i2cInst* inst , const unsigned short target , const unsigned char* address , int acount , unsigned char* value , int vcount )
{
	int error = 0 ,i = 0;
	if(target != inst->target)
	{
		inst->target = target;
		i2cSetTarget(target);
	}
	error = waitTFE(100);
	while( i < acount && !error)
	{
		I2C_WRITE (address[i++]);
		{
			int k = 4;
			while( k -- );
		}
	}
	i = 0;
	while( i < vcount && !error)
	{
		I2C_WRITE (value[i++]);
		{
			int k = 4;//33000/4;
			while( k -- );
		}
	}
	error = waitTFE(100);
	return error;
}

int i2cRead( i2cInst* inst , const unsigned short target , const unsigned char* address , int acount , unsigned char* value , int vcount )
{
	int error = 0 ,i = 0, tx_num = vcount;

   if (!g_i2c_base)
      return -1;

	if(target != inst->target)
	{
		inst->target = target;
		i2cSetTarget(target);
	}
   I2C_CON(I2CR_CON | 0x20);  /* Ruskee: Is it necessary to have this?*/
	error = waitTFE(100);
	while( i < acount && !error)
	{
		I2C_WRITE (address[i++]);
		{
			int k = 4;
			while( k -- );
		}
	}
	i = 0;
	error = waitTFE(1000);
	while( i < vcount && !error)
	{	
		while(((I2C_STATUS)&(TFNF))&&tx_num)
		{
			I2C_WRITE(0x100);	
			tx_num--;
		}
		error = waitRFNE(100);
		value[ i ] = I2C_READ;
		i++;
	}
	return error;
}