/* * PCF8563 RTC * * From Phillips' datasheet: * * The PCF8563 is a CMOS real-time clock/calendar optimized for low power * consumption. A programmable clock output, interupt output and voltage * low detector are also provided. All address and data are transferred * serially via two-line bidirectional I2C-bus. Maximum bus speed is * 400 kbits/s. The built-in word address register is incremented * automatically after each written or read byte. * * Copyright (c) 2002-2003, Axis Communications AB * All rights reserved. * * Author: Tobias Anderberg <tobiasa@axis.com>. * */#include <linux/config.h>#include <linux/module.h>#include <linux/kernel.h>#include <linux/types.h>#include <linux/sched.h>#include <linux/init.h>#include <linux/fs.h>#include <linux/ioctl.h>#include <linux/delay.h>#include <linux/bcd.h>#include <asm/uaccess.h>#include <asm/system.h>#include <asm/io.h>#include <asm/rtc.h>#include "i2c.h"#define PCF8563_MAJOR	121	/* Local major number. */#define DEVICE_NAME	"rtc"	/* Name which is registered in /proc/devices. */#define PCF8563_NAME	"PCF8563"#define DRIVER_VERSION	"$Revision: 1.1 $"/* Two simple wrapper macros, saves a few keystrokes. */#define rtc_read(x) i2c_readreg(RTC_I2C_READ, x)#define rtc_write(x,y) i2c_writereg(RTC_I2C_WRITE, x, y)static const unsigned char days_in_month[] =	{ 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };int pcf8563_ioctl(struct inode *, struct file *, unsigned int, unsigned long);int pcf8563_open(struct inode *, struct file *);int pcf8563_release(struct inode *, struct file *);static struct file_operations pcf8563_fops = {	owner: THIS_MODULE,	ioctl: pcf8563_ioctl,	open: pcf8563_open,	release: pcf8563_release,};unsigned charpcf8563_readreg(int reg){	unsigned char res = rtc_read(reg);	/* The PCF8563 does not return 0 for unimplemented bits */	switch (reg) {		case RTC_SECONDS:		case RTC_MINUTES:			res &= 0x7F;			break;		case RTC_HOURS:		case RTC_DAY_OF_MONTH:			res &= 0x3F;			break;		case RTC_WEEKDAY:			res &= 0x07;			break;		case RTC_MONTH:			res &= 0x1F;			break;		case RTC_CONTROL1:			res &= 0xA8;			break;		case RTC_CONTROL2:			res &= 0x1F;			break;		case RTC_CLOCKOUT_FREQ:		case RTC_TIMER_CONTROL:			res &= 0x83;			break;	}	return res;}voidpcf8563_writereg(int reg, unsigned char val){#ifdef CONFIG_ETRAX_RTC_READONLY	if (reg == RTC_CONTROL1 || (reg >= RTC_SECONDS && reg <= RTC_YEAR))		return;#endif	rtc_write(reg, val);}voidget_rtc_time(struct rtc_time *tm){	tm->tm_sec  = rtc_read(RTC_SECONDS);	tm->tm_min  = rtc_read(RTC_MINUTES);	tm->tm_hour = rtc_read(RTC_HOURS);	tm->tm_mday = rtc_read(RTC_DAY_OF_MONTH);	tm->tm_wday = rtc_read(RTC_WEEKDAY);	tm->tm_mon  = rtc_read(RTC_MONTH);	tm->tm_year = rtc_read(RTC_YEAR);	if (tm->tm_sec & 0x80)		printk(KERN_WARNING "%s: RTC Voltage Low - reliable date/time "		       "information is no longer guaranteed!\n", PCF8563_NAME);	tm->tm_year  = BCD_TO_BIN(tm->tm_year) + ((tm->tm_mon & 0x80) ? 100 : 0);	tm->tm_sec  &= 0x7F;	tm->tm_min  &= 0x7F;	tm->tm_hour &= 0x3F;	tm->tm_mday &= 0x3F;	tm->tm_wday &= 0x07; /* Not coded in BCD. */	tm->tm_mon  &= 0x1F;	BCD_TO_BIN(tm->tm_sec);	BCD_TO_BIN(tm->tm_min);	BCD_TO_BIN(tm->tm_hour);	BCD_TO_BIN(tm->tm_mday);	BCD_TO_BIN(tm->tm_mon);	tm->tm_mon--; /* Month is 1..12 in RTC but 0..11 in linux */}int __initpcf8563_init(void){	/* Initiate the i2c protocol. */	i2c_init();	/*	 * First of all we need to reset the chip. This is done by	 * clearing control1, control2 and clk freq and resetting	 * all alarms.	 */	if (rtc_write(RTC_CONTROL1, 0x00) < 0)		goto err;	if (rtc_write(RTC_CONTROL2, 0x00) < 0)		goto err;	if (rtc_write(RTC_CLOCKOUT_FREQ, 0x00) < 0)		goto err;	if (rtc_write(RTC_TIMER_CONTROL, 0x03) < 0)		goto err;	/* Reset the alarms. */	if (rtc_write(RTC_MINUTE_ALARM, 0x80) < 0)		goto err;	if (rtc_write(RTC_HOUR_ALARM, 0x80) < 0)		goto err;	if (rtc_write(RTC_DAY_ALARM, 0x80) < 0)		goto err;	if (rtc_write(RTC_WEEKDAY_ALARM, 0x80) < 0)		goto err;	if (register_chrdev(PCF8563_MAJOR, DEVICE_NAME, &pcf8563_fops) < 0) {		printk(KERN_INFO "%s: Unable to get major numer %d for RTC device.\n",		       PCF8563_NAME, PCF8563_MAJOR);		return -1;	}	printk(KERN_INFO "%s Real-Time Clock Driver, %s\n", PCF8563_NAME, DRIVER_VERSION);	/* Check for low voltage, and warn about it.. */	if (rtc_read(RTC_SECONDS) & 0x80)		printk(KERN_WARNING "%s: RTC Voltage Low - reliable date/time "		       "information is no longer guaranteed!\n", PCF8563_NAME);	return 0;err:	printk(KERN_INFO "%s: Error initializing chip.\n", PCF8563_NAME);	return -1;}void __exitpcf8563_exit(void){	if (unregister_chrdev(PCF8563_MAJOR, DEVICE_NAME) < 0) {		printk(KERN_INFO "%s: Unable to unregister device.\n", PCF8563_NAME);	}}/* * ioctl calls for this driver. Why return -ENOTTY upon error? Because * POSIX says so! */intpcf8563_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg){	/* Some sanity checks. */	if (_IOC_TYPE(cmd) != RTC_MAGIC)		return -ENOTTY;	if (_IOC_NR(cmd) > RTC_MAX_IOCTL)		return -ENOTTY;	switch (cmd) {		case RTC_RD_TIME:		{			struct rtc_time tm;			memset(&tm, 0, sizeof (struct rtc_time));			get_rtc_time(&tm);			if (copy_to_user((struct rtc_time *) arg, &tm, sizeof tm)) {				return -EFAULT;			}			return 0;		}		case RTC_SET_TIME:		{#ifdef CONFIG_ETRAX_RTC_READONLY			return -EPERM;#else			int leap;			int year;			int century;			struct rtc_time tm;			if (!capable(CAP_SYS_TIME))				return -EPERM;			if (copy_from_user(&tm, (struct rtc_time *) arg, sizeof tm))				return -EFAULT;			/* Convert from struct tm to struct rtc_time. */			tm.tm_year += 1900;			tm.tm_mon += 1;			/*			 * Check if tm.tm_year is a leap year. A year is a leap			 * year if it is divisible by 4 but not 100, except			 * that years divisible by 400 _are_ leap years.			 */			year = tm.tm_year;			leap = (tm.tm_mon == 2) && ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0);			/* Perform some sanity checks. */			if ((tm.tm_year < 1970) ||			    (tm.tm_mon > 12) ||			    (tm.tm_mday == 0) ||			    (tm.tm_mday > days_in_month[tm.tm_mon] + leap) ||			    (tm.tm_wday >= 7) ||			    (tm.tm_hour >= 24) ||			    (tm.tm_min >= 60) ||			    (tm.tm_sec >= 60))				return -EINVAL;			century = (tm.tm_year >= 2000) ? 0x80 : 0;			tm.tm_year = tm.tm_year % 100;			BIN_TO_BCD(tm.tm_year);			BIN_TO_BCD(tm.tm_mday);			BIN_TO_BCD(tm.tm_hour);			BIN_TO_BCD(tm.tm_min);			BIN_TO_BCD(tm.tm_sec);			tm.tm_mon |= century;			rtc_write(RTC_YEAR, tm.tm_year);			rtc_write(RTC_MONTH, tm.tm_mon);			rtc_write(RTC_WEEKDAY, tm.tm_wday); /* Not coded in BCD. */			rtc_write(RTC_DAY_OF_MONTH, tm.tm_mday);			rtc_write(RTC_HOURS, tm.tm_hour);			rtc_write(RTC_MINUTES, tm.tm_min);			rtc_write(RTC_SECONDS, tm.tm_sec);			return 0;#endif /* !CONFIG_ETRAX_RTC_READONLY */		}		case RTC_VLOW_RD:		{			int vl_bit = 0;			if (rtc_read(RTC_SECONDS) & 0x80) {				vl_bit = 1;				printk(KERN_WARNING "%s: RTC Voltage Low - reliable "				       "date/time information is no longer guaranteed!\n",				       PCF8563_NAME);			}			if (copy_to_user((int *) arg, &vl_bit, sizeof(int)))				return -EFAULT;			return 0;		}		case RTC_VLOW_SET:		{			/* Clear the VL bit in the seconds register */			int ret = rtc_read(RTC_SECONDS);			rtc_write(RTC_SECONDS, (ret & 0x7F));			return 0;		}		default:			return -ENOTTY;	}	return 0;}intpcf8563_open(struct inode *inode, struct file *filp){	MOD_INC_USE_COUNT;	return 0;}intpcf8563_release(struct inode *inode, struct file *filp){	MOD_DEC_USE_COUNT;	return 0;}module_init(pcf8563_init);module_exit(pcf8563_exit);