drivers/char/ds1302.c - kernel/msm-4.9 - Gitiles

 /*!***************************************************************************
 *!
 *! FILE NAME  : ds1302.c
 *!
 *! DESCRIPTION: Implements an interface for the DS1302 RTC
 *!
 *! Functions exported: ds1302_readreg, ds1302_writereg, ds1302_init, get_rtc_status
 *!
 *! ---------------------------------------------------------------------------
 *!
 *! (C) Copyright 1999, 2000, 2001  Axis Communications AB, LUND, SWEDEN
 *!
 *!***************************************************************************/


 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/miscdevice.h>
 #include <linux/delay.h>
 #include <linux/bcd.h>
 #include <linux/smp_lock.h>
 #include <linux/uaccess.h>
 #include <linux/io.h>

 #include <asm/system.h>
 #include <asm/rtc.h>
 #if defined(CONFIG_M32R)
 #include <asm/m32r.h>
 #endif

 #define RTC_MAJOR_NR 121 /* local major, change later */

 static const char ds1302_name[] = "ds1302";

 /* Send 8 bits. */
 static void
 out_byte_rtc(unsigned int reg_addr, unsigned char x)
 {
 	//RST H
 	outw(0x0001,(unsigned long)PLD_RTCRSTODT);
 	//write data
 	outw(((x<<8)|(reg_addr&0xff)),(unsigned long)PLD_RTCWRDATA);
 	//WE
 	outw(0x0002,(unsigned long)PLD_RTCCR);
 	//wait
 	while(inw((unsigned long)PLD_RTCCR));

 	//RST L
 	outw(0x0000,(unsigned long)PLD_RTCRSTODT);

 }

 static unsigned char
 in_byte_rtc(unsigned int reg_addr)
 {
 	unsigned char retval;

 	//RST H
 	outw(0x0001,(unsigned long)PLD_RTCRSTODT);
 	//write data
 	outw((reg_addr&0xff),(unsigned long)PLD_RTCRDDATA);
 	//RE
 	outw(0x0001,(unsigned long)PLD_RTCCR);
 	//wait
 	while(inw((unsigned long)PLD_RTCCR));

 	//read data
 	retval=(inw((unsigned long)PLD_RTCRDDATA) & 0xff00)>>8;

 	//RST L
 	outw(0x0000,(unsigned long)PLD_RTCRSTODT);

 	return retval;
 }

 /* Enable writing. */

 static void
 ds1302_wenable(void)
 {
 	out_byte_rtc(0x8e,0x00);
 }

 /* Disable writing. */

 static void
 ds1302_wdisable(void)
 {
 	out_byte_rtc(0x8e,0x80);
 }


 /* Read a byte from the selected register in the DS1302. */

 unsigned char
 ds1302_readreg(int reg)
 {
 	unsigned char x;

 	x=in_byte_rtc((0x81 | (reg << 1))); /* read register */

 	return x;
 }

 /* Write a byte to the selected register. */

 void
 ds1302_writereg(int reg, unsigned char val)
 {
 	ds1302_wenable();
 	out_byte_rtc((0x80 | (reg << 1)),val);
 	ds1302_wdisable();
 }

 void
 get_rtc_time(struct rtc_time *rtc_tm)
 {
 	unsigned long flags;

 	local_irq_save(flags);

 	rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
 	rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
 	rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
 	rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
 	rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
 	rtc_tm->tm_year = CMOS_READ(RTC_YEAR);

 	local_irq_restore(flags);

 	BCD_TO_BIN(rtc_tm->tm_sec);
 	BCD_TO_BIN(rtc_tm->tm_min);
 	BCD_TO_BIN(rtc_tm->tm_hour);
 	BCD_TO_BIN(rtc_tm->tm_mday);
 	BCD_TO_BIN(rtc_tm->tm_mon);
 	BCD_TO_BIN(rtc_tm->tm_year);

 	/*
 	 * Account for differences between how the RTC uses the values
 	 * and how they are defined in a struct rtc_time;
 	 */

 	if (rtc_tm->tm_year <= 69)
 		rtc_tm->tm_year += 100;

 	rtc_tm->tm_mon--;
 }

 static unsigned char days_in_mo[] =
     {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

 /* ioctl that supports RTC_RD_TIME and RTC_SET_TIME (read and set time/date). */

 static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	unsigned long flags;

 	switch(cmd) {
 		case RTC_RD_TIME:	/* read the time/date from RTC	*/
 		{
 			struct rtc_time rtc_tm;

 			memset(&rtc_tm, 0, sizeof (struct rtc_time));
 			lock_kernel();
 			get_rtc_time(&rtc_tm);
 			unlock_kernel();
 			if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time)))
 				return -EFAULT;
 			return 0;
 		}

 		case RTC_SET_TIME:	/* set the RTC */
 		{
 			struct rtc_time rtc_tm;
 			unsigned char mon, day, hrs, min, sec, leap_yr;
 			unsigned int yrs;

 			if (!capable(CAP_SYS_TIME))
 				return -EPERM;

 			if (copy_from_user(&rtc_tm, (struct rtc_time*)arg, sizeof(struct rtc_time)))
 				return -EFAULT;

 			yrs = rtc_tm.tm_year + 1900;
 			mon = rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */
 			day = rtc_tm.tm_mday;
 			hrs = rtc_tm.tm_hour;
 			min = rtc_tm.tm_min;
 			sec = rtc_tm.tm_sec;


 			if ((yrs < 1970) || (yrs > 2069))
 				return -EINVAL;

 			leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));

 			if ((mon > 12) || (day == 0))
 				return -EINVAL;

 			if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
 				return -EINVAL;

 			if ((hrs >= 24) || (min >= 60) || (sec >= 60))
 				return -EINVAL;

 			if (yrs >= 2000)
 				yrs -= 2000;	/* RTC (0, 1, ... 69) */
 			else
 				yrs -= 1900;	/* RTC (70, 71, ... 99) */

 			BIN_TO_BCD(sec);
 			BIN_TO_BCD(min);
 			BIN_TO_BCD(hrs);
 			BIN_TO_BCD(day);
 			BIN_TO_BCD(mon);
 			BIN_TO_BCD(yrs);

 			lock_kernel();
 			local_irq_save(flags);
 			CMOS_WRITE(yrs, RTC_YEAR);
 			CMOS_WRITE(mon, RTC_MONTH);
 			CMOS_WRITE(day, RTC_DAY_OF_MONTH);
 			CMOS_WRITE(hrs, RTC_HOURS);
 			CMOS_WRITE(min, RTC_MINUTES);
 			CMOS_WRITE(sec, RTC_SECONDS);
 			local_irq_restore(flags);
 			unlock_kernel();

 			/* Notice that at this point, the RTC is updated but
 			 * the kernel is still running with the old time.
 			 * You need to set that separately with settimeofday
 			 * or adjtimex.
 			 */
 			return 0;
 		}

 		case RTC_SET_CHARGE: /* set the RTC TRICKLE CHARGE register */
 		{
 			int tcs_val;

 			if (!capable(CAP_SYS_TIME))
 				return -EPERM;

 			if(copy_from_user(&tcs_val, (int*)arg, sizeof(int)))
 				return -EFAULT;

 			lock_kernel();
 			tcs_val = RTC_TCR_PATTERN | (tcs_val & 0x0F);
 			ds1302_writereg(RTC_TRICKLECHARGER, tcs_val);
 			unlock_kernel();
 			return 0;
 		}
 		default:
 			return -EINVAL;
 	}
 }

 int
 get_rtc_status(char *buf)
 {
 	char *p;
 	struct rtc_time tm;

 	p = buf;

 	get_rtc_time(&tm);

 	/*
 	 * There is no way to tell if the luser has the RTC set for local
 	 * time or for Universal Standard Time (GMT). Probably local though.
 	 */

 	p += sprintf(p,
 		"rtc_time\t: %02d:%02d:%02d\n"
 		"rtc_date\t: %04d-%02d-%02d\n",
 		tm.tm_hour, tm.tm_min, tm.tm_sec,
 		tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);

 	return  p - buf;
 }


 /* The various file operations we support. */

 static const struct file_operations rtc_fops = {
 	.owner		= THIS_MODULE,
 	.unlocked_ioctl	= rtc_ioctl,
 };

 /* Probe for the chip by writing something to its RAM and try reading it back. */

 #define MAGIC_PATTERN 0x42

 static int __init
 ds1302_probe(void)
 {
 	int retval, res, baur;

 	baur=(boot_cpu_data.bus_clock/(2*1000*1000));

 	printk("%s: Set PLD_RTCBAUR = %d\n", ds1302_name,baur);

 	outw(0x0000,(unsigned long)PLD_RTCCR);
 	outw(0x0000,(unsigned long)PLD_RTCRSTODT);
 	outw(baur,(unsigned long)PLD_RTCBAUR);

 	/* Try to talk to timekeeper. */

 	ds1302_wenable();
 	/* write RAM byte 0 */
 	/* write something magic */
 	out_byte_rtc(0xc0,MAGIC_PATTERN);

 	/* read RAM byte 0 */
 	if((res = in_byte_rtc(0xc1)) == MAGIC_PATTERN) {
 		char buf[100];
 		ds1302_wdisable();
 		printk("%s: RTC found.\n", ds1302_name);
 		get_rtc_status(buf);
 		printk(buf);
 		retval = 1;
 	} else {
 		printk("%s: RTC not found.\n", ds1302_name);
 		retval = 0;
 	}

 	return retval;
 }


 /* Just probe for the RTC and register the device to handle the ioctl needed. */

 int __init
 ds1302_init(void)
 {
 	if (!ds1302_probe()) {
 		return -1;
   	}
 	return 0;
 }

 static int __init ds1302_register(void)
 {
 	ds1302_init();
 	if (register_chrdev(RTC_MAJOR_NR, ds1302_name, &rtc_fops)) {
 		printk(KERN_INFO "%s: unable to get major %d for rtc\n",
 		       ds1302_name, RTC_MAJOR_NR);
 		return -1;
 	}
 	return 0;
 }

 module_init(ds1302_register);
	/!**************************************************************************
	*!
	*! FILE NAME : ds1302.c
	*!
	*! DESCRIPTION: Implements an interface for the DS1302 RTC
	*!
	*! Functions exported: ds1302_readreg, ds1302_writereg, ds1302_init, get_rtc_status
	*!
	*! ---------------------------------------------------------------------------
	*!
	*! (C) Copyright 1999, 2000, 2001 Axis Communications AB, LUND, SWEDEN
	*!
	!**************************************************************************/


	#include <linux/fs.h>
	#include <linux/init.h>
	#include <linux/mm.h>
	#include <linux/module.h>
	#include <linux/miscdevice.h>
	#include <linux/delay.h>
	#include <linux/bcd.h>
	#include <linux/smp_lock.h>
	#include <linux/uaccess.h>
	#include <linux/io.h>

	#include <asm/system.h>
	#include <asm/rtc.h>
	#if defined(CONFIG_M32R)
	#include <asm/m32r.h>
	#endif

	#define RTC_MAJOR_NR 121 /* local major, change later */

	static const char ds1302_name[] = "ds1302";

	/* Send 8 bits. */
	static void
	out_byte_rtc(unsigned int reg_addr, unsigned char x)
	{
	//RST H
	outw(0x0001,(unsigned long)PLD_RTCRSTODT);
	//write data
	outw(((x<<8)\|(reg_addr&0xff)),(unsigned long)PLD_RTCWRDATA);
	//WE
	outw(0x0002,(unsigned long)PLD_RTCCR);
	//wait
	while(inw((unsigned long)PLD_RTCCR));

	//RST L
	outw(0x0000,(unsigned long)PLD_RTCRSTODT);

	}

	static unsigned char
	in_byte_rtc(unsigned int reg_addr)
	{
	unsigned char retval;

	//RST H
	outw(0x0001,(unsigned long)PLD_RTCRSTODT);
	//write data
	outw((reg_addr&0xff),(unsigned long)PLD_RTCRDDATA);
	//RE
	outw(0x0001,(unsigned long)PLD_RTCCR);
	//wait
	while(inw((unsigned long)PLD_RTCCR));

	//read data
	retval=(inw((unsigned long)PLD_RTCRDDATA) & 0xff00)>>8;

	//RST L
	outw(0x0000,(unsigned long)PLD_RTCRSTODT);

	return retval;
	}

	/* Enable writing. */

	static void
	ds1302_wenable(void)
	{
	out_byte_rtc(0x8e,0x00);
	}

	/* Disable writing. */

	static void
	ds1302_wdisable(void)
	{
	out_byte_rtc(0x8e,0x80);
	}



	/* Read a byte from the selected register in the DS1302. */

	unsigned char
	ds1302_readreg(int reg)
	{
	unsigned char x;

	x=in_byte_rtc((0x81 \| (reg << 1))); /* read register */

	return x;
	}

	/* Write a byte to the selected register. */

	void
	ds1302_writereg(int reg, unsigned char val)
	{
	ds1302_wenable();
	out_byte_rtc((0x80 \| (reg << 1)),val);
	ds1302_wdisable();
	}

	void
	get_rtc_time(struct rtc_time *rtc_tm)
	{
	unsigned long flags;

	local_irq_save(flags);

	rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
	rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
	rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
	rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
	rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
	rtc_tm->tm_year = CMOS_READ(RTC_YEAR);

	local_irq_restore(flags);

	BCD_TO_BIN(rtc_tm->tm_sec);
	BCD_TO_BIN(rtc_tm->tm_min);
	BCD_TO_BIN(rtc_tm->tm_hour);
	BCD_TO_BIN(rtc_tm->tm_mday);
	BCD_TO_BIN(rtc_tm->tm_mon);
	BCD_TO_BIN(rtc_tm->tm_year);

	/*
	* Account for differences between how the RTC uses the values
	* and how they are defined in a struct rtc_time;
	*/

	if (rtc_tm->tm_year <= 69)
	rtc_tm->tm_year += 100;

	rtc_tm->tm_mon--;
	}

	static unsigned char days_in_mo[] =
	{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

	/* ioctl that supports RTC_RD_TIME and RTC_SET_TIME (read and set time/date). */

	static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
	{
	unsigned long flags;

	switch(cmd) {
	case RTC_RD_TIME: /* read the time/date from RTC */
	{
	struct rtc_time rtc_tm;

	memset(&rtc_tm, 0, sizeof (struct rtc_time));
	lock_kernel();
	get_rtc_time(&rtc_tm);
	unlock_kernel();
	if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time)))
	return -EFAULT;
	return 0;
	}

	case RTC_SET_TIME: /* set the RTC */
	{
	struct rtc_time rtc_tm;
	unsigned char mon, day, hrs, min, sec, leap_yr;
	unsigned int yrs;

	if (!capable(CAP_SYS_TIME))
	return -EPERM;

	if (copy_from_user(&rtc_tm, (struct rtc_time*)arg, sizeof(struct rtc_time)))
	return -EFAULT;

	yrs = rtc_tm.tm_year + 1900;
	mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
	day = rtc_tm.tm_mday;
	hrs = rtc_tm.tm_hour;
	min = rtc_tm.tm_min;
	sec = rtc_tm.tm_sec;


	if ((yrs < 1970) \|\| (yrs > 2069))
	return -EINVAL;

	leap_yr = ((!(yrs % 4) && (yrs % 100)) \|\| !(yrs % 400));

	if ((mon > 12) \|\| (day == 0))
	return -EINVAL;

	if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
	return -EINVAL;

	if ((hrs >= 24) \|\| (min >= 60) \|\| (sec >= 60))
	return -EINVAL;

	if (yrs >= 2000)
	yrs -= 2000; /* RTC (0, 1, ... 69) */
	else
	yrs -= 1900; /* RTC (70, 71, ... 99) */

	BIN_TO_BCD(sec);
	BIN_TO_BCD(min);
	BIN_TO_BCD(hrs);
	BIN_TO_BCD(day);
	BIN_TO_BCD(mon);
	BIN_TO_BCD(yrs);

	lock_kernel();
	local_irq_save(flags);
	CMOS_WRITE(yrs, RTC_YEAR);
	CMOS_WRITE(mon, RTC_MONTH);
	CMOS_WRITE(day, RTC_DAY_OF_MONTH);
	CMOS_WRITE(hrs, RTC_HOURS);
	CMOS_WRITE(min, RTC_MINUTES);
	CMOS_WRITE(sec, RTC_SECONDS);
	local_irq_restore(flags);
	unlock_kernel();

	/* Notice that at this point, the RTC is updated but
	* the kernel is still running with the old time.
	* You need to set that separately with settimeofday
	* or adjtimex.
	*/
	return 0;
	}

	case RTC_SET_CHARGE: /* set the RTC TRICKLE CHARGE register */
	{
	int tcs_val;

	if (!capable(CAP_SYS_TIME))
	return -EPERM;

	if(copy_from_user(&tcs_val, (int*)arg, sizeof(int)))
	return -EFAULT;

	lock_kernel();
	tcs_val = RTC_TCR_PATTERN \| (tcs_val & 0x0F);
	ds1302_writereg(RTC_TRICKLECHARGER, tcs_val);
	unlock_kernel();
	return 0;
	}
	default:
	return -EINVAL;
	}
	}

	int
	get_rtc_status(char *buf)
	{
	char *p;
	struct rtc_time tm;

	p = buf;

	get_rtc_time(&tm);

	/*
	* There is no way to tell if the luser has the RTC set for local
	* time or for Universal Standard Time (GMT). Probably local though.
	*/

	p += sprintf(p,
	"rtc_time\t: %02d:%02d:%02d\n"
	"rtc_date\t: %04d-%02d-%02d\n",
	tm.tm_hour, tm.tm_min, tm.tm_sec,
	tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);

	return p - buf;
	}


	/* The various file operations we support. */

	static const struct file_operations rtc_fops = {
	.owner = THIS_MODULE,
	.unlocked_ioctl = rtc_ioctl,
	};

	/* Probe for the chip by writing something to its RAM and try reading it back. */

	#define MAGIC_PATTERN 0x42

	static int __init
	ds1302_probe(void)
	{
	int retval, res, baur;

	baur=(boot_cpu_data.bus_clock/(210001000));

	printk("%s: Set PLD_RTCBAUR = %d\n", ds1302_name,baur);

	outw(0x0000,(unsigned long)PLD_RTCCR);
	outw(0x0000,(unsigned long)PLD_RTCRSTODT);
	outw(baur,(unsigned long)PLD_RTCBAUR);

	/* Try to talk to timekeeper. */

	ds1302_wenable();
	/* write RAM byte 0 */
	/* write something magic */
	out_byte_rtc(0xc0,MAGIC_PATTERN);

	/* read RAM byte 0 */
	if((res = in_byte_rtc(0xc1)) == MAGIC_PATTERN) {
	char buf[100];
	ds1302_wdisable();
	printk("%s: RTC found.\n", ds1302_name);
	get_rtc_status(buf);
	printk(buf);
	retval = 1;
	} else {
	printk("%s: RTC not found.\n", ds1302_name);
	retval = 0;
	}

	return retval;
	}


	/* Just probe for the RTC and register the device to handle the ioctl needed. */

	int __init
	ds1302_init(void)
	{
	if (!ds1302_probe()) {
	return -1;
	}
	return 0;
	}

	static int __init ds1302_register(void)
	{
	ds1302_init();
	if (register_chrdev(RTC_MAJOR_NR, ds1302_name, &rtc_fops)) {
	printk(KERN_INFO "%s: unable to get major %d for rtc\n",
	ds1302_name, RTC_MAJOR_NR);
	return -1;
	}
	return 0;
	}

	module_init(ds1302_register);