i2c.c

H9200F(2.6.12)的音频接口驱动。 操作方法： 1、将驱动程序rsound.ko拷贝到系统目录：/lib/modules 2、执行如下命令加载模块： insmod /

/******************************

	MX1 I2C / iMagic Driver

*******************************/

#include <asm/hardware.h>
#include <asm/arch/AT91RM9200_TWI.h>
#include <asm/arch/pio.h>
#include <asm/delay.h>
#include "i2c.h"
//#include <asm/arch/at91rm9200dk.h>

//#define I2C_CLKDIV    0x17    //(100kbps for 96MHz BCLK)
#define I2C_CLKDIV	0x13
//      Sensor Slave Address
#define UDA1380_ADD	(0x30/2)
//#define UDA1380_ADD   (0x34/2)

#if 10
#define PDEBUG	printk
#else
#define PDEBUG
#endif
void UDA1380_SetTwiClock(unsigned int mck_khz)
{
	int sclock;

	/* Here, CKDIV = 1 and CHDIV=CLDIV  ==> CLDIV = CHDIV = 1/4*((Fmclk/FTWI) -6) */
	sclock = (10 * mck_khz / 400);
	if (sclock % 10 >= 5)
		sclock = (sclock / 10) - 5;
	else
		sclock = (sclock / 10) - 6;
	sclock = (sclock + (4 - sclock % 4)) >> 2;	// div 4

	((AT91PS_TWI) AT91C_VA_BASE_TWI)->TWI_CWGR = 0x00010000 | sclock |
	    (sclock << 8);
}
void port_init_I2C(void)
{
	AT91PS_TWI twi = (AT91PS_TWI) AT91C_VA_BASE_TWI;
	struct at91_i2c_local *device;
	int rc;

	AT91_CfgPIO_TWI();

#if 10
/*reset 1380*/
	AT91_SYS->PIOB_PER = AT91C_PB2_TD0;
	AT91_SYS->PIOB_OER = AT91C_PB2_TD0;

	AT91_SYS->PIOB_OWER = AT91C_PB2_TD0;
        AT91_SYS->PIOB_SODR = AT91C_PB2_TD0;
	udelay(1000);
	AT91_SYS->PIOB_CODR = AT91C_PB2_TD0;
	udelay(1000);
	AT91_SYS->PIOB_ODSR &= ~AT91C_PB2_TD0;
	udelay(1000);
	udelay(1000);
#endif
	twi->TWI_IDR = 0x1c7;	/* Disable all interrupts */
	//twi->TWI_IDR = (unsigned int) -1;	/* Disable all interrupts */
	twi->TWI_CR = AT91C_TWI_SWRST;	/* Reset peripheral */
	twi->TWI_CR = AT91C_TWI_MSEN;// | AT91C_TWI_SVDIS;	/* Set Master mode */

	/* Here, CKDIV = 1 and CHDIV=CLDIV  ==> CLDIV = CHDIV = 1/4*((Fmclk/FTWI) -6) */
	// Set TWI Clock Waveform Generator Register
	UDA1380_SetTwiClock(900000);	// MCK in KHz = 60000 KHz

//      twi->TWI_CWGR = AT91C_TWI_CKDIV1 | AT91C_TWI_CLDIV3 | (AT91C_TWI_CLDIV3 << 8);
//	printk("twi->TWI_CWGR = %x\n",
//	       AT91C_TWI_CKDIV1 | AT91C_TWI_CLDIV3 | (AT91C_TWI_CLDIV3 << 8));
/*enable timer for i2c*/
	AT91_SYS->PMC_PCER = 1 << AT91C_ID_TWI;	/* enable peripheral clock */

	return;
}


int I2C_write(char reg_address, unsigned short data_out, int length)
{
	AT91PS_TWI twi = (AT91PS_TWI) AT91C_VA_BASE_TWI;
	unsigned char *buf = &data_out;
	int m = 0 , n = 0;
//	PDEBUG("data to write : buf[0]=%x,buf[1]=%x\n", buf[0], buf[1]);
	((AT91PS_TWI) AT91C_VA_BASE_TWI)->TWI_MMR =
	    (AT91C_TWI_MREAD & 0x0) | AT91C_TWI_IADRSZ_1_BYTE |
	    ((UDA1380_ADD << 16) & AT91C_TWI_DADR);

	((AT91PS_TWI) AT91C_VA_BASE_TWI)->TWI_IADR =
	    (unsigned int) reg_address;

	twi->TWI_CR = AT91C_TWI_START;

	while (length--) {
		twi->TWI_THR = *buf++;
		if (!length)
			twi->TWI_CR = AT91C_TWI_STOP;
		do {
			m++;
			if(m > 1000) {
				printk("Iic write error!\n");
				return 0;
			}
			udelay(10);
		} while (!(twi->TWI_SR & AT91C_TWI_TXRDY));
	}
	/* Wait until transfer is finished */
	do {
		n++;
		if(n > 1000) {
			printk("Iic write error!\n");
			return 0;
		}
		udelay(10);
	} while (!(twi->TWI_SR & AT91C_TWI_TXCOMP));
}


/*length should be 2,when read one single register*/
int I2C_read(char reg_address, unsigned short *data_in, int length)
{
	int Status, nb_trial, i;
	unsigned int initial_timeout;
	unsigned char msb, lsb;
	unsigned char *buf = data_in;
	int k = 0 , l = 0 ;

	AT91PS_TWI twi = (AT91PS_TWI) AT91C_VA_BASE_TWI;

	((AT91PS_TWI) AT91C_VA_BASE_TWI)->TWI_MMR =
	    (AT91C_TWI_MREAD) | AT91C_TWI_IADRSZ_1_BYTE |
	    ((UDA1380_ADD << 16) & AT91C_TWI_DADR);


	((AT91PS_TWI) AT91C_VA_BASE_TWI)->TWI_IADR =
	    (unsigned int) reg_address;

	((AT91PS_TWI) AT91C_VA_BASE_TWI)->TWI_CR =
	    (unsigned int) (AT91C_TWI_START);


	while (length--) {
		if (!length)
			twi->TWI_CR = AT91C_TWI_STOP;
		/* Wait until transfer is finished */
		do{
			k++;
			if(k > 1000) {
				printk("Iic read error!\n");
				return 0;
			}
			udelay(10);
		} while (!(twi->TWI_SR & AT91C_TWI_RXRDY));
		*buf++ = twi->TWI_RHR;
	}
	do {
		l++;
		if(l > 1000) {
			printk("Iic read error!\n");
			return 0;
		}
		udelay(10);
	} while (!(twi->TWI_SR & AT91C_TWI_TXCOMP));

}



//      Test on I2C channel
//
//      Read / write one of the register
//      compare and verify if the data is correct
//
unsigned int I2C_test(void)
{
	unsigned int rdata = 0;
	unsigned int wdata = 0;
	unsigned int tmpdata = 0;


	port_init_I2C();
/*
	I2C_read(0x00,&rdata,2);
	PDEBUG("0x00 init value=%x\n",rdata);
	I2C_write(0x00,0x0607,2);
	I2C_read(0x00,&rdata,2);
	PDEBUG("0x00 is set to=%x\n",rdata);
*/
	I2C_read(0x12,&rdata,2);
	PDEBUG("0x12 init value=%x\n",rdata);
	I2C_write(0x12,0x1562,2);
	I2C_read(0x12,&rdata,2);
	PDEBUG("0x12 is set to=%x\n",rdata);

#if 0
	wdata = 0x55aa;		//least 10 bits can be R/W

	udelay(1000);
	I2C_write(0x11, wdata, 2);
	udelay(1000);

	I2C_read(0x11, &rdata, 2);
	PDEBUG("rdata: %x\n", rdata);

	if (rdata == wdata) {
		printk("I2C test OK\n");
	} else {
		printk("I2C test FAIL\n");
	}

	I2C_write(0x10, tmpdata, 2);
	I2C_read(0x10, &rdata, 2);
	PDEBUG("Recover to: %x\n", rdata);
#endif
	return 0;		//OK
}