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