+++ /dev/null
-/*
- * 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/smp_lock.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 <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 long rtc_ioctl(struct file *filp, 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 long rtc_ioctl(struct file *filp, 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)
-{
- lock_kernel();
- spin_lock_irq(&rtc_lock);
-
- if (rtc_status & RTC_IS_OPEN) {
- spin_unlock_irq(&rtc_lock);
- unlock_kernel();
- return -EBUSY;
- }
-
- rtc_status |= RTC_IS_OPEN;
- spin_unlock_irq(&rtc_lock);
- unlock_kernel();
-
- 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 const struct file_operations rtc_fops = {
- .owner = THIS_MODULE,
- .unlocked_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--;
-}
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