1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
327 lines
7.5 KiB
C
327 lines
7.5 KiB
C
/*
|
|
* Driver for the SGS-Thomson M48T35 Timekeeper RAM chip
|
|
*
|
|
* Real Time Clock interface for Linux
|
|
*
|
|
* TODO: Implement periodic interrupts.
|
|
*
|
|
* Copyright (C) 2000 Silicon Graphics, Inc.
|
|
* Written by Ulf Carlsson (ulfc@engr.sgi.com)
|
|
*
|
|
* Based on code written by Paul Gortmaker.
|
|
*
|
|
* This driver allows use of the real time clock (built into
|
|
* nearly all computers) from user space. It exports the /dev/rtc
|
|
* interface supporting various ioctl() and also the /proc/rtc
|
|
* pseudo-file for status information.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the License, or (at your option) any later version.
|
|
*
|
|
*/
|
|
|
|
#define RTC_VERSION "1.09b"
|
|
|
|
#include <linux/bcd.h>
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/types.h>
|
|
#include <linux/miscdevice.h>
|
|
#include <linux/ioport.h>
|
|
#include <linux/fcntl.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/init.h>
|
|
#include <linux/poll.h>
|
|
#include <linux/proc_fs.h>
|
|
#include <linux/smp_lock.h>
|
|
|
|
#include <asm/m48t35.h>
|
|
#include <asm/sn/ioc3.h>
|
|
#include <asm/io.h>
|
|
#include <asm/uaccess.h>
|
|
#include <asm/system.h>
|
|
#include <asm/sn/klconfig.h>
|
|
#include <asm/sn/sn0/ip27.h>
|
|
#include <asm/sn/sn0/hub.h>
|
|
#include <asm/sn/sn_private.h>
|
|
|
|
static int rtc_ioctl(struct inode *inode, struct file *file,
|
|
unsigned int cmd, unsigned long arg);
|
|
|
|
static int rtc_read_proc(char *page, char **start, off_t off,
|
|
int count, int *eof, void *data);
|
|
|
|
static void get_rtc_time(struct rtc_time *rtc_tm);
|
|
|
|
/*
|
|
* Bits in rtc_status. (6 bits of room for future expansion)
|
|
*/
|
|
|
|
#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
|
|
#define RTC_TIMER_ON 0x02 /* missed irq timer active */
|
|
|
|
static unsigned char rtc_status; /* bitmapped status byte. */
|
|
static unsigned long rtc_freq; /* Current periodic IRQ rate */
|
|
static struct m48t35_rtc *rtc;
|
|
|
|
/*
|
|
* If this driver ever becomes modularised, it will be really nice
|
|
* to make the epoch retain its value across module reload...
|
|
*/
|
|
|
|
static unsigned long epoch = 1970; /* year corresponding to 0x00 */
|
|
|
|
static const unsigned char days_in_mo[] =
|
|
{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
|
|
|
|
static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
|
|
struct rtc_time wtime;
|
|
|
|
switch (cmd) {
|
|
case RTC_RD_TIME: /* Read the time/date from RTC */
|
|
{
|
|
get_rtc_time(&wtime);
|
|
break;
|
|
}
|
|
case RTC_SET_TIME: /* Set the RTC */
|
|
{
|
|
struct rtc_time rtc_tm;
|
|
unsigned char mon, day, hrs, min, sec, leap_yr;
|
|
unsigned int yrs;
|
|
|
|
if (!capable(CAP_SYS_TIME))
|
|
return -EACCES;
|
|
|
|
if (copy_from_user(&rtc_tm, (struct rtc_time*)arg,
|
|
sizeof(struct rtc_time)))
|
|
return -EFAULT;
|
|
|
|
yrs = rtc_tm.tm_year + 1900;
|
|
mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
|
|
day = rtc_tm.tm_mday;
|
|
hrs = rtc_tm.tm_hour;
|
|
min = rtc_tm.tm_min;
|
|
sec = rtc_tm.tm_sec;
|
|
|
|
if (yrs < 1970)
|
|
return -EINVAL;
|
|
|
|
leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
|
|
|
|
if ((mon > 12) || (day == 0))
|
|
return -EINVAL;
|
|
|
|
if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
|
|
return -EINVAL;
|
|
|
|
if ((hrs >= 24) || (min >= 60) || (sec >= 60))
|
|
return -EINVAL;
|
|
|
|
if ((yrs -= epoch) > 255) /* They are unsigned */
|
|
return -EINVAL;
|
|
|
|
if (yrs > 169)
|
|
return -EINVAL;
|
|
|
|
if (yrs >= 100)
|
|
yrs -= 100;
|
|
|
|
sec = BIN2BCD(sec);
|
|
min = BIN2BCD(min);
|
|
hrs = BIN2BCD(hrs);
|
|
day = BIN2BCD(day);
|
|
mon = BIN2BCD(mon);
|
|
yrs = BIN2BCD(yrs);
|
|
|
|
spin_lock_irq(&rtc_lock);
|
|
rtc->control |= M48T35_RTC_SET;
|
|
rtc->year = yrs;
|
|
rtc->month = mon;
|
|
rtc->date = day;
|
|
rtc->hour = hrs;
|
|
rtc->min = min;
|
|
rtc->sec = sec;
|
|
rtc->control &= ~M48T35_RTC_SET;
|
|
spin_unlock_irq(&rtc_lock);
|
|
|
|
return 0;
|
|
}
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
return copy_to_user((void *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
|
|
}
|
|
|
|
/*
|
|
* We enforce only one user at a time here with the open/close.
|
|
* Also clear the previous interrupt data on an open, and clean
|
|
* up things on a close.
|
|
*/
|
|
|
|
static int rtc_open(struct inode *inode, struct file *file)
|
|
{
|
|
spin_lock_irq(&rtc_lock);
|
|
|
|
if (rtc_status & RTC_IS_OPEN) {
|
|
spin_unlock_irq(&rtc_lock);
|
|
return -EBUSY;
|
|
}
|
|
|
|
rtc_status |= RTC_IS_OPEN;
|
|
spin_unlock_irq(&rtc_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int rtc_release(struct inode *inode, struct file *file)
|
|
{
|
|
/*
|
|
* Turn off all interrupts once the device is no longer
|
|
* in use, and clear the data.
|
|
*/
|
|
|
|
spin_lock_irq(&rtc_lock);
|
|
rtc_status &= ~RTC_IS_OPEN;
|
|
spin_unlock_irq(&rtc_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* The various file operations we support.
|
|
*/
|
|
|
|
static struct file_operations rtc_fops = {
|
|
.owner = THIS_MODULE,
|
|
.ioctl = rtc_ioctl,
|
|
.open = rtc_open,
|
|
.release = rtc_release,
|
|
};
|
|
|
|
static struct miscdevice rtc_dev=
|
|
{
|
|
RTC_MINOR,
|
|
"rtc",
|
|
&rtc_fops
|
|
};
|
|
|
|
static int __init rtc_init(void)
|
|
{
|
|
rtc = (struct m48t35_rtc *)
|
|
(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base + IOC3_BYTEBUS_DEV0);
|
|
|
|
printk(KERN_INFO "Real Time Clock Driver v%s\n", RTC_VERSION);
|
|
if (misc_register(&rtc_dev)) {
|
|
printk(KERN_ERR "rtc: cannot register misc device.\n");
|
|
return -ENODEV;
|
|
}
|
|
if (!create_proc_read_entry("driver/rtc", 0, NULL, rtc_read_proc, NULL)) {
|
|
printk(KERN_ERR "rtc: cannot create /proc/rtc.\n");
|
|
misc_deregister(&rtc_dev);
|
|
return -ENOENT;
|
|
}
|
|
|
|
rtc_freq = 1024;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit rtc_exit (void)
|
|
{
|
|
/* interrupts and timer disabled at this point by rtc_release */
|
|
|
|
remove_proc_entry ("rtc", NULL);
|
|
misc_deregister(&rtc_dev);
|
|
}
|
|
|
|
module_init(rtc_init);
|
|
module_exit(rtc_exit);
|
|
|
|
/*
|
|
* Info exported via "/proc/rtc".
|
|
*/
|
|
|
|
static int rtc_get_status(char *buf)
|
|
{
|
|
char *p;
|
|
struct rtc_time tm;
|
|
|
|
/*
|
|
* Just emulate the standard /proc/rtc
|
|
*/
|
|
|
|
p = buf;
|
|
|
|
get_rtc_time(&tm);
|
|
|
|
/*
|
|
* There is no way to tell if the luser has the RTC set for local
|
|
* time or for Universal Standard Time (GMT). Probably local though.
|
|
*/
|
|
p += sprintf(p,
|
|
"rtc_time\t: %02d:%02d:%02d\n"
|
|
"rtc_date\t: %04d-%02d-%02d\n"
|
|
"rtc_epoch\t: %04lu\n"
|
|
"24hr\t\t: yes\n",
|
|
tm.tm_hour, tm.tm_min, tm.tm_sec,
|
|
tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
|
|
|
|
return p - buf;
|
|
}
|
|
|
|
static int rtc_read_proc(char *page, char **start, off_t off,
|
|
int count, int *eof, void *data)
|
|
{
|
|
int len = rtc_get_status(page);
|
|
if (len <= off+count) *eof = 1;
|
|
*start = page + off;
|
|
len -= off;
|
|
if (len>count) len = count;
|
|
if (len<0) len = 0;
|
|
return len;
|
|
}
|
|
|
|
static void get_rtc_time(struct rtc_time *rtc_tm)
|
|
{
|
|
/*
|
|
* Do we need to wait for the last update to finish?
|
|
*/
|
|
|
|
/*
|
|
* Only the values that we read from the RTC are set. We leave
|
|
* tm_wday, tm_yday and tm_isdst untouched. Even though the
|
|
* RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
|
|
* by the RTC when initially set to a non-zero value.
|
|
*/
|
|
spin_lock_irq(&rtc_lock);
|
|
rtc->control |= M48T35_RTC_READ;
|
|
rtc_tm->tm_sec = rtc->sec;
|
|
rtc_tm->tm_min = rtc->min;
|
|
rtc_tm->tm_hour = rtc->hour;
|
|
rtc_tm->tm_mday = rtc->date;
|
|
rtc_tm->tm_mon = rtc->month;
|
|
rtc_tm->tm_year = rtc->year;
|
|
rtc->control &= ~M48T35_RTC_READ;
|
|
spin_unlock_irq(&rtc_lock);
|
|
|
|
rtc_tm->tm_sec = BCD2BIN(rtc_tm->tm_sec);
|
|
rtc_tm->tm_min = BCD2BIN(rtc_tm->tm_min);
|
|
rtc_tm->tm_hour = BCD2BIN(rtc_tm->tm_hour);
|
|
rtc_tm->tm_mday = BCD2BIN(rtc_tm->tm_mday);
|
|
rtc_tm->tm_mon = BCD2BIN(rtc_tm->tm_mon);
|
|
rtc_tm->tm_year = BCD2BIN(rtc_tm->tm_year);
|
|
|
|
/*
|
|
* Account for differences between how the RTC uses the values
|
|
* and how they are defined in a struct rtc_time;
|
|
*/
|
|
if ((rtc_tm->tm_year += (epoch - 1900)) <= 69)
|
|
rtc_tm->tm_year += 100;
|
|
|
|
rtc_tm->tm_mon--;
|
|
}
|