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/* $Id: rtc.c,v 1.28 2001/10/08 22:19:51 davem Exp $
*
* Linux/SPARC Real Time Clock Driver
* Copyright (C) 1996 Thomas K. Dyas (tdyas@eden.rutgers.edu)
*
* This is a little driver that lets a user-level program access
* the SPARC Mostek real time clock chip. It is no use unless you
* use the modified clock utility.
*
* Get the modified clock utility from:
* ftp://vger.kernel.org/pub/linux/Sparc/userland/clock.c
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/fcntl.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <asm/mostek.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/rtc.h>
static int rtc_busy = 0;
/* Retrieve the current date and time from the real time clock. */
void get_rtc_time(struct rtc_time *t)
{
unsigned long regs = mstk48t02_regs;
u8 tmp;
spin_lock_irq(&mostek_lock);
tmp = mostek_read(regs + MOSTEK_CREG);
tmp |= MSTK_CREG_READ;
mostek_write(regs + MOSTEK_CREG, tmp);
t->sec = MSTK_REG_SEC(regs);
t->min = MSTK_REG_MIN(regs);
t->hour = MSTK_REG_HOUR(regs);
t->dow = MSTK_REG_DOW(regs);
t->dom = MSTK_REG_DOM(regs);
t->month = MSTK_REG_MONTH(regs);
t->year = MSTK_CVT_YEAR( MSTK_REG_YEAR(regs) );
tmp = mostek_read(regs + MOSTEK_CREG);
tmp &= ~MSTK_CREG_READ;
mostek_write(regs + MOSTEK_CREG, tmp);
spin_unlock_irq(&mostek_lock);
}
/* Set the current date and time inthe real time clock. */
void set_rtc_time(struct rtc_time *t)
{
unsigned long regs = mstk48t02_regs;
u8 tmp;
spin_lock_irq(&mostek_lock);
tmp = mostek_read(regs + MOSTEK_CREG);
tmp |= MSTK_CREG_WRITE;
mostek_write(regs + MOSTEK_CREG, tmp);
MSTK_SET_REG_SEC(regs,t->sec);
MSTK_SET_REG_MIN(regs,t->min);
MSTK_SET_REG_HOUR(regs,t->hour);
MSTK_SET_REG_DOW(regs,t->dow);
MSTK_SET_REG_DOM(regs,t->dom);
MSTK_SET_REG_MONTH(regs,t->month);
MSTK_SET_REG_YEAR(regs,t->year - MSTK_YEAR_ZERO);
tmp = mostek_read(regs + MOSTEK_CREG);
tmp &= ~MSTK_CREG_WRITE;
mostek_write(regs + MOSTEK_CREG, tmp);
spin_unlock_irq(&mostek_lock);
}
static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
struct rtc_time rtc_tm;
switch (cmd)
{
case RTCGET:
get_rtc_time(&rtc_tm);
if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time)))
return -EFAULT;
return 0;
case RTCSET:
if (!capable(CAP_SYS_TIME))
return -EPERM;
if (copy_from_user(&rtc_tm, (struct rtc_time*)arg, sizeof(struct rtc_time)))
return -EFAULT;
set_rtc_time(&rtc_tm);
return 0;
default:
return -EINVAL;
}
}
static int rtc_open(struct inode *inode, struct file *file)
{
int ret;
spin_lock_irq(&mostek_lock);
if (rtc_busy) {
ret = -EBUSY;
} else {
rtc_busy = 1;
ret = 0;
}
spin_unlock_irq(&mostek_lock);
return ret;
}
static int rtc_release(struct inode *inode, struct file *file)
{
rtc_busy = 0;
return 0;
}
static struct file_operations rtc_fops = {
owner: THIS_MODULE,
llseek: no_llseek,
ioctl: rtc_ioctl,
open: rtc_open,
release: rtc_release,
};
static struct miscdevice rtc_dev = { RTC_MINOR, "rtc", &rtc_fops };
EXPORT_NO_SYMBOLS;
static int __init rtc_sun_init(void)
{
int error;
/* It is possible we are being driven by some other RTC chip
* and thus another RTC driver is handling things.
*/
if (mstk48t02_regs == 0)
return -ENODEV;
error = misc_register(&rtc_dev);
if (error) {
printk(KERN_ERR "rtc: unable to get misc minor for Mostek\n");
return error;
}
return 0;
}
static void __exit rtc_sun_cleanup(void)
{
misc_deregister(&rtc_dev);
}
module_init(rtc_sun_init);
module_exit(rtc_sun_cleanup);
MODULE_LICENSE("GPL");
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