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/*
* Linux/PowerPC Real Time Clock Driver
*
* heavily based on:
* 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 PPC clocks chip. It is no use unless you
* use the modified clock utility.
*
* Get the modified clock utility from:
* ftp://vger.rutgers.edu/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/mc146818rtc.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/machdep.h>
#include <asm/time.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 nowtime;
nowtime = (ppc_md.get_rtc_time)();
to_tm(nowtime, t);
t->tm_year -= 1900;
t->tm_mon -= 1; /* Make sure userland has a 0-based month */
}
/* Set the current date and time in the real time clock. */
void set_rtc_time(struct rtc_time *t)
{
unsigned long nowtime;
nowtime = mktime(t->tm_year+1900, t->tm_mon+1, t->tm_mday,
t->tm_hour, t->tm_min, t->tm_sec);
(ppc_md.set_rtc_time)(nowtime);
}
static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
unsigned long arg)
{
struct rtc_time rtc_tm;
switch (cmd)
{
case RTC_RD_TIME:
if (ppc_md.get_rtc_time)
{
get_rtc_time(&rtc_tm);
if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time)))
return -EFAULT;
return 0;
}
else
return -EINVAL;
case RTC_SET_TIME:
if (!capable(CAP_SYS_TIME))
return -EPERM;
if (ppc_md.set_rtc_time)
{
if (copy_from_user(&rtc_tm, (struct rtc_time*)arg, sizeof(struct rtc_time)))
return -EFAULT;
set_rtc_time(&rtc_tm);
return 0;
}
else
return -EINVAL;
default:
return -EINVAL;
}
}
static int rtc_open(struct inode *inode, struct file *file)
{
if (rtc_busy)
return -EBUSY;
rtc_busy = 1;
MOD_INC_USE_COUNT;
return 0;
}
static int rtc_release(struct inode *inode, struct file *file)
{
MOD_DEC_USE_COUNT;
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_init(void)
{
int error;
error = misc_register(&rtc_dev);
if (error) {
printk(KERN_ERR "rtc: unable to get misc minor\n");
return error;
}
return 0;
}
static void __exit rtc_exit(void)
{
misc_deregister(&rtc_dev);
}
module_init(rtc_init);
module_exit(rtc_exit);
MODULE_LICENSE("GPL");
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