cpu/s3c44b0/cpu.c - uboot/mindspeed - Git at Google

 /*
  * (C) Copyright 2004
  * DAVE Srl
  * http://www.dave-tech.it
  * http://www.wawnet.biz
  * mailto:info@wawnet.biz
  *
  * See file CREDITS for list of people who contributed to this
  * project.
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation; either version 2 of
  * the License, or (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  * MA 02111-1307 USA
  */

 /*
  * S3C44B0 CPU specific code
  */

 #include <common.h>
 #include <command.h>
 #include <asm/hardware.h>

 static void s3c44b0_flush_cache(void)
 {
 	volatile int i;
 	/* flush cycle */
 	for(i=0x10002000;i<0x10004800;i+=16)
 	{
 		*((int *)i)=0x0;
 	}
 }


 int cpu_init (void)
 {
 	icache_enable();

 	return 0;
 }

 int cleanup_before_linux (void)
 {
 	/*
 		cache memory should be enabled before calling
 		Linux to make the kernel uncompression faster
 	*/
 	icache_enable();

 	disable_interrupts ();

 	return 0;
 }

 void reset_cpu (ulong addr)
 {
 	/*
 		reset the cpu using watchdog
 	*/

 	/* Disable the watchdog.*/
 	WTCON&=~(1<<5);

 	/* set the timeout value to a short time... */
 	WTCNT = 0x1;

 	/* Enable the watchdog. */
 	WTCON|=1;
 	WTCON|=(1<<5);

 	while(1) {
 		/*NOP*/
 	}
 }

 int do_reset (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 {
 	disable_interrupts ();
 	reset_cpu (0);

 	/*NOTREACHED*/
 	return (0);
 }

 void icache_enable (void)
 {
 	ulong reg;

 	s3c44b0_flush_cache();

 	/*
 		Init cache
 		Non-cacheable area (everything outside RAM)
 		0x0000:0000 - 0x0C00:0000
 	 */
 	NCACHBE0 = 0xC0000000;
 	NCACHBE1 = 0x00000000;

 	/*
 		Enable chache
 	*/
 	reg = SYSCFG;
 	reg |= 0x00000006; /* 8kB */
 	SYSCFG = reg;
 }

 void icache_disable (void)
 {
 	ulong reg;

 	reg = SYSCFG;
 	reg &= ~0x00000006; /* 8kB */
 	SYSCFG = reg;
 }

 int icache_status (void)
 {
 	return 0;
 }

 void dcache_enable (void)
 {
 	icache_enable();
 }

 void dcache_disable (void)
 {
 	icache_disable();
 }

 int dcache_status (void)
 {
 	return dcache_status();
 }

 /*
 	RTC stuff
 */
 #include <rtc.h>
 #ifndef BCD2HEX
 	#define BCD2HEX(n)  ((n>>4)*10+(n&0x0f))
 #endif
 #ifndef HEX2BCD
 	#define HEX2BCD(x) ((((x) / 10) << 4) + (x) % 10)
 #endif

 void rtc_get (struct rtc_time* tm)
 {
 	RTCCON |= 1;
 	tm->tm_year  = BCD2HEX(BCDYEAR);
 	tm->tm_mon   = BCD2HEX(BCDMON);
 	tm->tm_wday   = BCD2HEX(BCDDATE);
 	tm->tm_mday   = BCD2HEX(BCDDAY);
 	tm->tm_hour  = BCD2HEX(BCDHOUR);
 	tm->tm_min  = BCD2HEX(BCDMIN);
 	tm->tm_sec  = BCD2HEX(BCDSEC);

 	if (tm->tm_sec==0) {
 		/* we have to re-read the rtc data because of the "one second deviation" problem */
 		/* see RTC datasheet for more info about it */
 		tm->tm_year  = BCD2HEX(BCDYEAR);
 		tm->tm_mon   = BCD2HEX(BCDMON);
 		tm->tm_mday   = BCD2HEX(BCDDAY);
 		tm->tm_wday   = BCD2HEX(BCDDATE);
 		tm->tm_hour  = BCD2HEX(BCDHOUR);
 		tm->tm_min  = BCD2HEX(BCDMIN);
 		tm->tm_sec  = BCD2HEX(BCDSEC);
 	}

 	RTCCON &= ~1;

 	if(tm->tm_year >= 70)
 		tm->tm_year += 1900;
 	else
 		tm->tm_year += 2000;
 }

 void rtc_set (struct rtc_time* tm)
 {
 	if(tm->tm_year < 2000)
 		tm->tm_year -= 1900;
 	else
 		tm->tm_year -= 2000;

 	RTCCON |= 1;
 	BCDYEAR = HEX2BCD(tm->tm_year);
 	BCDMON = HEX2BCD(tm->tm_mon);
 	BCDDAY = HEX2BCD(tm->tm_mday);
 	BCDDATE = HEX2BCD(tm->tm_wday);
 	BCDHOUR = HEX2BCD(tm->tm_hour);
 	BCDMIN = HEX2BCD(tm->tm_min);
 	BCDSEC = HEX2BCD(tm->tm_sec);
 	RTCCON &= 1;
 }

 void rtc_reset (void)
 {
 	RTCCON |= 1;
 	BCDYEAR = 0;
 	BCDMON = 0;
 	BCDDAY = 0;
 	BCDDATE = 0;
 	BCDHOUR = 0;
 	BCDMIN = 0;
 	BCDSEC = 0;
 	RTCCON &= 1;
 }


 /*
 	I2C stuff
 */

 /*
  * Initialization, must be called once on start up, may be called
  * repeatedly to change the speed and slave addresses.
  */
 void i2c_init(int speed, int slaveaddr)
 {
 	/*
 		setting up I2C support
 	*/
 	unsigned int save_F,save_PF,rIICCON,rPCONA,rPDATA,rPCONF,rPUPF;

 	save_F = PCONF;
 	save_PF = PUPF;

 	rPCONF = ((save_F & ~(0xF))| 0xa);
 	rPUPF = (save_PF | 0x3);
 	PCONF = rPCONF; /*PF0:IICSCL, PF1:IICSDA*/
 	PUPF = rPUPF; /* Disable pull-up */

 	/* Configuring pin for WC pin of EEprom */
 	rPCONA = PCONA;
 	rPCONA &= ~(1<<9);
 	PCONA = rPCONA;

 	rPDATA = PDATA;
 	rPDATA &= ~(1<<9);
 	PDATA = rPDATA;

 	/*
 		Enable ACK, IICCLK=MCLK/16, enable interrupt
 		75Mhz/16/(12+1) = 390625 Hz
 	*/
 	rIICCON=(1<<7)|(0<<6)|(1<<5)|(0xC);
 	IICCON = rIICCON;

 	IICADD = slaveaddr;
 }

 /*
  * Probe the given I2C chip address.  Returns 0 if a chip responded,
  * not 0 on failure.
  */
 int i2c_probe(uchar chip)
 {
 	/*
 		not implemented
 	*/

 	printf("i2c_probe chip %d\n", (int) chip);
 	return -1;
 }

 /*
  * Read/Write interface:
  *   chip:    I2C chip address, range 0..127
  *   addr:    Memory (register) address within the chip
  *   alen:    Number of bytes to use for addr (typically 1, 2 for larger
  *              memories, 0 for register type devices with only one
  *              register)
  *   buffer:  Where to read/write the data
  *   len:     How many bytes to read/write
  *
  *   Returns: 0 on success, not 0 on failure
  */

 #define S3C44B0X_rIIC_INTPEND               (1<<4)
 #define S3C44B0X_rIIC_LAST_RECEIV_BIT       (1<<0)
 #define S3C44B0X_rIIC_INTERRUPT_ENABLE      (1<<5)
 #define S3C44B0_IIC_TIMEOUT 100

 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 {

 	int k, j, temp;
 	u32 rIICSTAT;

 	/*
 		send the device offset
 	*/

 	rIICSTAT = 0xD0;
 	IICSTAT = rIICSTAT;

 	IICDS = chip;	/* this is a write operation... */

 	rIICSTAT |= (1<<5);
 	IICSTAT = rIICSTAT;

 	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
 		temp = IICCON;
 		if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
 		break;
 		udelay(2000);
 	}
 	if (k==S3C44B0_IIC_TIMEOUT)
 		return -1;

 	/* wait and check ACK */
 	temp = IICSTAT;
 	if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT )
 		return -1;

 	IICDS = addr;
 	IICCON = IICCON & ~(S3C44B0X_rIIC_INTPEND);

 	/* wait and check ACK */
 	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
 		temp = IICCON;
 		if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
 		break;
 		udelay(2000);
 	}
 	if (k==S3C44B0_IIC_TIMEOUT)
 		return -1;

 	temp = IICSTAT;
 	if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT )
 		return -1;

 	/*
 		now we can start with the read operation...
 	*/

 	IICDS = chip | 0x01;	/* this is a read operation... */

 	rIICSTAT = 0x90; /*master recv*/
 	rIICSTAT |= (1<<5);
 	IICSTAT = rIICSTAT;

 	IICCON = IICCON & ~(S3C44B0X_rIIC_INTPEND);

 	/* wait and check ACK */
 	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
 		temp = IICCON;
 		if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
 		break;
 		udelay(2000);
 	}
 	if (k==S3C44B0_IIC_TIMEOUT)
 		return -1;

 	temp = IICSTAT;
 	if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT )
 		return -1;

 	for (j=0; j<len-1; j++) {

 	/*clear pending bit to resume */

 	temp = IICCON & ~(S3C44B0X_rIIC_INTPEND);
 	IICCON = temp;

 	/* wait and check ACK */
 	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
 		temp = IICCON;
 		if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
 		break;
 		udelay(2000);
 	}
 	if (k==S3C44B0_IIC_TIMEOUT)
 		return -1;


 		buffer[j] = IICDS; /*save readed data*/

     } /*end for(j)*/

 	/*
 		reading the last data
 		unset ACK generation
 	*/
 	temp = IICCON & ~(S3C44B0X_rIIC_INTPEND | (1<<7));
 	IICCON = temp;

 	/* wait but NOT check ACK */
 	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
 		temp = IICCON;
 		if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
 		break;
 		udelay(2000);
 	}
 	if (k==S3C44B0_IIC_TIMEOUT)
 		return -1;

 	buffer[j] = IICDS; /*save readed data*/

 	rIICSTAT = 0x90; /*master recv*/

 	/* Write operation Terminate sending STOP */
 	IICSTAT = rIICSTAT;
 	/*Clear Int Pending Bit to RESUME*/
 	temp = IICCON;
 	IICCON = temp & (~S3C44B0X_rIIC_INTPEND);

 	IICCON = IICCON | (1<<7);	/*restore ACK generation*/

 	return 0;
 }

 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
 {
 	int j, k;
 	u32 rIICSTAT, temp;


 	/*
 		send the device offset
 	*/

 	rIICSTAT = 0xD0;
 	IICSTAT = rIICSTAT;

 	IICDS = chip;	/* this is a write operation... */

 	rIICSTAT |= (1<<5);
 	IICSTAT = rIICSTAT;

 	IICCON = IICCON & ~(S3C44B0X_rIIC_INTPEND);

 	/* wait and check ACK */
 	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
 		temp = IICCON;
 		if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
 		break;
 		udelay(2000);
 	}
 	if (k==S3C44B0_IIC_TIMEOUT)
 		return -1;

 	temp = IICSTAT;
 	if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT )
 		return -1;

 	IICDS = addr;
 	IICCON = IICCON & ~(S3C44B0X_rIIC_INTPEND);

 	/* wait and check ACK */
 	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
 		temp = IICCON;
 		if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
 		break;
 		udelay(2000);
 	}
 	if (k==S3C44B0_IIC_TIMEOUT)
 	  return -1;

 	temp = IICSTAT;
 	if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT )
 		return -1;

 	/*
 		now we can start with the read write operation
 	*/
 	for (j=0; j<len; j++) {

 		IICDS = buffer[j]; /*prerare data to write*/

 		/*clear pending bit to resume*/

 		temp = IICCON & ~(S3C44B0X_rIIC_INTPEND);
 		IICCON = temp;

 		/* wait but NOT check ACK */
 		for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
 			temp = IICCON;
 			if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
 			break;

 			udelay(2000);
 		}

 		if (k==S3C44B0_IIC_TIMEOUT)
 			return -1;

 	} /* end for(j) */

 	/* sending stop to terminate */
 	rIICSTAT = 0xD0;  /*master send*/
 	IICSTAT = rIICSTAT;
 	/*Clear Int Pending Bit to RESUME*/
 	temp = IICCON;
 	IICCON = temp & (~S3C44B0X_rIIC_INTPEND);

 	return 0;
 }
	/*
	* (C) Copyright 2004
	* DAVE Srl
	* http://www.dave-tech.it
	* http://www.wawnet.biz
	* mailto:info@wawnet.biz
	*
	* See file CREDITS for list of people who contributed to this
	* project.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License as
	* published by the Free Software Foundation; either version 2 of
	* the License, or (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	* MA 02111-1307 USA
	*/

	/*
	* S3C44B0 CPU specific code
	*/

	#include <common.h>
	#include <command.h>
	#include <asm/hardware.h>

	static void s3c44b0_flush_cache(void)
	{
	volatile int i;
	/* flush cycle */
	for(i=0x10002000;i<0x10004800;i+=16)
	{
	((int )i)=0x0;
	}
	}


	int cpu_init (void)
	{
	icache_enable();

	return 0;
	}

	int cleanup_before_linux (void)
	{
	/*
	cache memory should be enabled before calling
	Linux to make the kernel uncompression faster
	*/
	icache_enable();

	disable_interrupts ();

	return 0;
	}

	void reset_cpu (ulong addr)
	{
	/*
	reset the cpu using watchdog
	*/

	/* Disable the watchdog.*/
	WTCON&=~(1<<5);

	/* set the timeout value to a short time... */
	WTCNT = 0x1;

	/* Enable the watchdog. */
	WTCON\|=1;
	WTCON\|=(1<<5);

	while(1) {
	/NOP/
	}
	}

	int do_reset (cmd_tbl_t cmdtp, int flag, int argc, char argv[])
	{
	disable_interrupts ();
	reset_cpu (0);

	/NOTREACHED/
	return (0);
	}

	void icache_enable (void)
	{
	ulong reg;

	s3c44b0_flush_cache();

	/*
	Init cache
	Non-cacheable area (everything outside RAM)
	0x0000:0000 - 0x0C00:0000
	*/
	NCACHBE0 = 0xC0000000;
	NCACHBE1 = 0x00000000;

	/*
	Enable chache
	*/
	reg = SYSCFG;
	reg \|= 0x00000006; /* 8kB */
	SYSCFG = reg;
	}

	void icache_disable (void)
	{
	ulong reg;

	reg = SYSCFG;
	reg &= ~0x00000006; /* 8kB */
	SYSCFG = reg;
	}

	int icache_status (void)
	{
	return 0;
	}

	void dcache_enable (void)
	{
	icache_enable();
	}

	void dcache_disable (void)
	{
	icache_disable();
	}

	int dcache_status (void)
	{
	return dcache_status();
	}

	/*
	RTC stuff
	*/
	#include <rtc.h>
	#ifndef BCD2HEX
	#define BCD2HEX(n) ((n>>4)*10+(n&0x0f))
	#endif
	#ifndef HEX2BCD
	#define HEX2BCD(x) ((((x) / 10) << 4) + (x) % 10)
	#endif

	void rtc_get (struct rtc_time* tm)
	{
	RTCCON \|= 1;
	tm->tm_year = BCD2HEX(BCDYEAR);
	tm->tm_mon = BCD2HEX(BCDMON);
	tm->tm_wday = BCD2HEX(BCDDATE);
	tm->tm_mday = BCD2HEX(BCDDAY);
	tm->tm_hour = BCD2HEX(BCDHOUR);
	tm->tm_min = BCD2HEX(BCDMIN);
	tm->tm_sec = BCD2HEX(BCDSEC);

	if (tm->tm_sec==0) {
	/* we have to re-read the rtc data because of the "one second deviation" problem */
	/* see RTC datasheet for more info about it */
	tm->tm_year = BCD2HEX(BCDYEAR);
	tm->tm_mon = BCD2HEX(BCDMON);
	tm->tm_mday = BCD2HEX(BCDDAY);
	tm->tm_wday = BCD2HEX(BCDDATE);
	tm->tm_hour = BCD2HEX(BCDHOUR);
	tm->tm_min = BCD2HEX(BCDMIN);
	tm->tm_sec = BCD2HEX(BCDSEC);
	}

	RTCCON &= ~1;

	if(tm->tm_year >= 70)
	tm->tm_year += 1900;
	else
	tm->tm_year += 2000;
	}

	void rtc_set (struct rtc_time* tm)
	{
	if(tm->tm_year < 2000)
	tm->tm_year -= 1900;
	else
	tm->tm_year -= 2000;

	RTCCON \|= 1;
	BCDYEAR = HEX2BCD(tm->tm_year);
	BCDMON = HEX2BCD(tm->tm_mon);
	BCDDAY = HEX2BCD(tm->tm_mday);
	BCDDATE = HEX2BCD(tm->tm_wday);
	BCDHOUR = HEX2BCD(tm->tm_hour);
	BCDMIN = HEX2BCD(tm->tm_min);
	BCDSEC = HEX2BCD(tm->tm_sec);
	RTCCON &= 1;
	}

	void rtc_reset (void)
	{
	RTCCON \|= 1;
	BCDYEAR = 0;
	BCDMON = 0;
	BCDDAY = 0;
	BCDDATE = 0;
	BCDHOUR = 0;
	BCDMIN = 0;
	BCDSEC = 0;
	RTCCON &= 1;
	}


	/*
	I2C stuff
	*/

	/*
	* Initialization, must be called once on start up, may be called
	* repeatedly to change the speed and slave addresses.
	*/
	void i2c_init(int speed, int slaveaddr)
	{
	/*
	setting up I2C support
	*/
	unsigned int save_F,save_PF,rIICCON,rPCONA,rPDATA,rPCONF,rPUPF;

	save_F = PCONF;
	save_PF = PUPF;

	rPCONF = ((save_F & ~(0xF))\| 0xa);
	rPUPF = (save_PF \| 0x3);
	PCONF = rPCONF; /PF0:IICSCL, PF1:IICSDA/
	PUPF = rPUPF; /* Disable pull-up */

	/* Configuring pin for WC pin of EEprom */
	rPCONA = PCONA;
	rPCONA &= ~(1<<9);
	PCONA = rPCONA;

	rPDATA = PDATA;
	rPDATA &= ~(1<<9);
	PDATA = rPDATA;

	/*
	Enable ACK, IICCLK=MCLK/16, enable interrupt
	75Mhz/16/(12+1) = 390625 Hz
	*/
	rIICCON=(1<<7)\|(0<<6)\|(1<<5)\|(0xC);
	IICCON = rIICCON;

	IICADD = slaveaddr;
	}

	/*
	* Probe the given I2C chip address. Returns 0 if a chip responded,
	* not 0 on failure.
	*/
	int i2c_probe(uchar chip)
	{
	/*
	not implemented
	*/

	printf("i2c_probe chip %d\n", (int) chip);
	return -1;
	}

	/*
	* Read/Write interface:
	* chip: I2C chip address, range 0..127
	* addr: Memory (register) address within the chip
	* alen: Number of bytes to use for addr (typically 1, 2 for larger
	* memories, 0 for register type devices with only one
	* register)
	* buffer: Where to read/write the data
	* len: How many bytes to read/write
	*
	* Returns: 0 on success, not 0 on failure
	*/

	#define S3C44B0X_rIIC_INTPEND (1<<4)
	#define S3C44B0X_rIIC_LAST_RECEIV_BIT (1<<0)
	#define S3C44B0X_rIIC_INTERRUPT_ENABLE (1<<5)
	#define S3C44B0_IIC_TIMEOUT 100

	int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
	{

	int k, j, temp;
	u32 rIICSTAT;

	/*
	send the device offset
	*/

	rIICSTAT = 0xD0;
	IICSTAT = rIICSTAT;

	IICDS = chip; /* this is a write operation... */

	rIICSTAT \|= (1<<5);
	IICSTAT = rIICSTAT;

	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
	temp = IICCON;
	if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
	break;
	udelay(2000);
	}
	if (k==S3C44B0_IIC_TIMEOUT)
	return -1;

	/* wait and check ACK */
	temp = IICSTAT;
	if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT )
	return -1;

	IICDS = addr;
	IICCON = IICCON & ~(S3C44B0X_rIIC_INTPEND);

	/* wait and check ACK */
	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
	temp = IICCON;
	if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
	break;
	udelay(2000);
	}
	if (k==S3C44B0_IIC_TIMEOUT)
	return -1;

	temp = IICSTAT;
	if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT )
	return -1;

	/*
	now we can start with the read operation...
	*/

	IICDS = chip \| 0x01; /* this is a read operation... */

	rIICSTAT = 0x90; /master recv/
	rIICSTAT \|= (1<<5);
	IICSTAT = rIICSTAT;

	IICCON = IICCON & ~(S3C44B0X_rIIC_INTPEND);

	/* wait and check ACK */
	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
	temp = IICCON;
	if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
	break;
	udelay(2000);
	}
	if (k==S3C44B0_IIC_TIMEOUT)
	return -1;

	temp = IICSTAT;
	if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT )
	return -1;

	for (j=0; j<len-1; j++) {

	/clear pending bit to resume /

	temp = IICCON & ~(S3C44B0X_rIIC_INTPEND);
	IICCON = temp;

	/* wait and check ACK */
	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
	temp = IICCON;
	if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
	break;
	udelay(2000);
	}
	if (k==S3C44B0_IIC_TIMEOUT)
	return -1;


	buffer[j] = IICDS; /save readed data/

	} /end for(j)/

	/*
	reading the last data
	unset ACK generation
	*/
	temp = IICCON & ~(S3C44B0X_rIIC_INTPEND \| (1<<7));
	IICCON = temp;

	/* wait but NOT check ACK */
	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
	temp = IICCON;
	if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
	break;
	udelay(2000);
	}
	if (k==S3C44B0_IIC_TIMEOUT)
	return -1;

	buffer[j] = IICDS; /save readed data/

	rIICSTAT = 0x90; /master recv/

	/* Write operation Terminate sending STOP */
	IICSTAT = rIICSTAT;
	/Clear Int Pending Bit to RESUME/
	temp = IICCON;
	IICCON = temp & (~S3C44B0X_rIIC_INTPEND);

	IICCON = IICCON \| (1<<7); /restore ACK generation/

	return 0;
	}

	int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
	{
	int j, k;
	u32 rIICSTAT, temp;


	/*
	send the device offset
	*/

	rIICSTAT = 0xD0;
	IICSTAT = rIICSTAT;

	IICDS = chip; /* this is a write operation... */

	rIICSTAT \|= (1<<5);
	IICSTAT = rIICSTAT;

	IICCON = IICCON & ~(S3C44B0X_rIIC_INTPEND);

	/* wait and check ACK */
	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
	temp = IICCON;
	if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
	break;
	udelay(2000);
	}
	if (k==S3C44B0_IIC_TIMEOUT)
	return -1;

	temp = IICSTAT;
	if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT )
	return -1;

	IICDS = addr;
	IICCON = IICCON & ~(S3C44B0X_rIIC_INTPEND);

	/* wait and check ACK */
	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
	temp = IICCON;
	if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
	break;
	udelay(2000);
	}
	if (k==S3C44B0_IIC_TIMEOUT)
	return -1;

	temp = IICSTAT;
	if ((temp & S3C44B0X_rIIC_LAST_RECEIV_BIT) == S3C44B0X_rIIC_LAST_RECEIV_BIT )
	return -1;

	/*
	now we can start with the read write operation
	*/
	for (j=0; j<len; j++) {

	IICDS = buffer[j]; /prerare data to write/

	/clear pending bit to resume/

	temp = IICCON & ~(S3C44B0X_rIIC_INTPEND);
	IICCON = temp;

	/* wait but NOT check ACK */
	for(k=0; k<S3C44B0_IIC_TIMEOUT; k++) {
	temp = IICCON;
	if( (temp & S3C44B0X_rIIC_INTPEND) == S3C44B0X_rIIC_INTPEND)
	break;

	udelay(2000);
	}

	if (k==S3C44B0_IIC_TIMEOUT)
	return -1;

	} /* end for(j) */

	/* sending stop to terminate */
	rIICSTAT = 0xD0; /master send/
	IICSTAT = rIICSTAT;
	/Clear Int Pending Bit to RESUME/
	temp = IICCON;
	IICCON = temp & (~S3C44B0X_rIIC_INTPEND);

	return 0;
	}