/*
* 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 char
pcf8563_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;
}
void
pcf8563_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);
}
void
get_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 __init
pcf8563_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 __exit
pcf8563_exit(void)
{
unregister_chrdev(PCF8563_MAJOR, DEVICE_NAME);
}
/*
* ioctl calls for this driver. Why return -ENOTTY upon error? Because
* POSIX says so!
*/
int
pcf8563_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 __init
pcf8563_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);
