/* * PCF8563 RTC * * From Phillips' datasheet: * * The PCF8563 is a CMOS real-time clock/calendar optimized for low power * consumption. A programmable clock output, interrupt 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 bute. * * Copyright (c) 2002, Axis Communications AB * All rights reserved. * * Author: Tobias Anderberg <tobiasa@axis.com>. * * $Id: pcf8563.c,v 1.11 2005/03/07 13:13:07 starvik Exp $ */#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 <linux/capability.h>#include <asm/uaccess.h>#include <asm/system.h>#include <asm/io.h>#include <asm/arch/svinto.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: 1.11 $"/* I2C bus slave registers. */#define RTC_I2C_READ		0xa3#define RTC_I2C_WRITE		0xa2/* 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 DEFINE_SPINLOCK(rtc_lock); /* Protect state etc */	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);static const struct file_operations pcf8563_fops = {	.owner = THIS_MODULE,	.ioctl = pcf8563_ioctl,};unsigned charpcf8563_readreg(int reg) {	unsigned char res = i2c_readreg(RTC_I2C_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_MONTH:		     res = (res & 0x1f) - 1;  /* PCF8563 returns month in range 1-12 */		     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_mon = rtc_read(RTC_MONTH);	tm->tm_year = rtc_read(RTC_YEAR);	if (tm->tm_sec & 0x80)		printk(KERN_WARNING "%s: RTC Low Voltage - date/time is not reliable!\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_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){	int ret;	if ((ret = i2c_init())) {		printk(KERN_CRIT "pcf8563_init: failed to init i2c\n");		return ret;	}	/*	 * First of all we need to reset the chip. This is done by	 * clearing control1, control2 and clk freq, clear the 	 * Voltage Low bit, 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;	/* Clear the VL bit in the seconds register. */	ret = rtc_read(RTC_SECONDS);		if (rtc_write(RTC_SECONDS, (ret & 0x7f)) < 0)		goto err;			/* Reset the alarms. */	if (rtc_write(RTC_MINUTE_ALARM, 0x00) < 0)		goto err;		if (rtc_write(RTC_HOUR_ALARM, 0x00) < 0)		goto err;		if (rtc_write(RTC_DAY_ALARM, 0x00) < 0)		goto err;		if (rtc_write(RTC_WEEKDAY_ALARM, 0x00) < 0)		goto err;        	/* Check for low voltage, and warn about it.. */	if (rtc_read(RTC_SECONDS) & 0x80)		printk(KERN_WARNING "%s: RTC Low Voltage - date/time is not reliable!\n", PCF8563_NAME);		return 0;err:	printk(KERN_INFO "%s: Error initializing chip.\n", PCF8563_NAME);	return -1;}void __exitpcf8563_exit(void){	unregister_chrdev(PCF8563_MAJOR, DEVICE_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;				spin_lock(&rtc_lock);				get_rtc_time(&tm);				if (copy_to_user((struct rtc_time *) arg, &tm, sizeof(struct rtc_time))) {					spin_unlock(&rtc_lock);					return -EFAULT;				}				spin_unlock(&rtc_lock);				return 0;			}			break;		case RTC_SET_TIME:			{#ifdef CONFIG_ETRAX_RTC_READONLY				return -EPERM;#else				int leap;				int century;				struct rtc_time tm;				memset(&tm, 0, sizeof (struct rtc_time));				if (!capable(CAP_SYS_TIME))					return -EPERM;				if (copy_from_user(&tm, (struct rtc_time *) arg, sizeof(struct rtc_time)))					return -EFAULT;				/* Convert from struct tm to struct rtc_time. */				tm.tm_year += 1900;				tm.tm_mon += 1;								leap = ((tm.tm_mon == 2) && ((tm.tm_year % 4) == 0)) ? 1 : 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_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;				spin_lock(&rtc_lock);								rtc_write(RTC_YEAR, tm.tm_year);				rtc_write(RTC_MONTH, tm.tm_mon);				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);				spin_unlock(&rtc_lock);				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;}static int __initpcf8563_register(void){	pcf8563_init();	if (register_chrdev(PCF8563_MAJOR, DEVICE_NAME, &pcf8563_fops) < 0) {		printk(KERN_INFO "%s: Unable to get major number %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);        return 0;}module_init(pcf8563_register);module_exit(pcf8563_exit);