LXR linux/arch/m68k/mvme16x/rtc.c

   1/*
   2 *      Real Time Clock interface for Linux on the MVME16x
   3 *
   4 * Based on the PC driver by Paul Gortmaker.
   5 */
   6
   7#define RTC_VERSION             "1.00"
   8
   9#include <linux/types.h>
  10#include <linux/errno.h>
  11#include <linux/miscdevice.h>
  12#include <linux/slab.h>
  13#include <linux/smp_lock.h>
  14#include <linux/ioport.h>
  15#include <linux/capability.h>
  16#include <linux/fcntl.h>
  17#include <linux/init.h>
  18#include <linux/poll.h>
  19#include <linux/mc146818rtc.h>  /* For struct rtc_time and ioctls, etc */
  20#include <linux/bcd.h>
  21#include <asm/mvme16xhw.h>
  22
  23#include <asm/io.h>
  24#include <asm/uaccess.h>
  25#include <asm/system.h>
  26#include <asm/setup.h>
  27
  28/*
  29 *      We sponge a minor off of the misc major. No need slurping
  30 *      up another valuable major dev number for this. If you add
  31 *      an ioctl, make sure you don't conflict with SPARC's RTC
  32 *      ioctls.
  33 */
  34
  35static const unsigned char days_in_mo[] =
  36{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  37
  38static atomic_t rtc_ready = ATOMIC_INIT(1);
  39
  40static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
  41                     unsigned long arg)
  42{
  43        volatile MK48T08ptr_t rtc = (MK48T08ptr_t)MVME_RTC_BASE;
  44        unsigned long flags;
  45        struct rtc_time wtime;
  46        void __user *argp = (void __user *)arg;
  47
  48        switch (cmd) {
  49        case RTC_RD_TIME:       /* Read the time/date from RTC  */
  50        {
  51                local_irq_save(flags);
  52                /* Ensure clock and real-time-mode-register are accessible */
  53                rtc->ctrl = RTC_READ;
  54                memset(&wtime, 0, sizeof(struct rtc_time));
  55                wtime.tm_sec =  bcd2bin(rtc->bcd_sec);
  56                wtime.tm_min =  bcd2bin(rtc->bcd_min);
  57                wtime.tm_hour = bcd2bin(rtc->bcd_hr);
  58                wtime.tm_mday =  bcd2bin(rtc->bcd_dom);
  59                wtime.tm_mon =  bcd2bin(rtc->bcd_mth)-1;
  60                wtime.tm_year = bcd2bin(rtc->bcd_year);
  61                if (wtime.tm_year < 70)
  62                        wtime.tm_year += 100;
  63                wtime.tm_wday = bcd2bin(rtc->bcd_dow)-1;
  64                rtc->ctrl = 0;
  65                local_irq_restore(flags);
  66                return copy_to_user(argp, &wtime, sizeof wtime) ?
  67                                                                -EFAULT : 0;
  68        }
  69        case RTC_SET_TIME:      /* Set the RTC */
  70        {
  71                struct rtc_time rtc_tm;
  72                unsigned char mon, day, hrs, min, sec, leap_yr;
  73                unsigned int yrs;
  74
  75                if (!capable(CAP_SYS_ADMIN))
  76                        return -EACCES;
  77
  78                if (copy_from_user(&rtc_tm, argp, sizeof(struct rtc_time)))
  79                        return -EFAULT;
  80
  81                yrs = rtc_tm.tm_year;
  82                if (yrs < 1900)
  83                        yrs += 1900;
  84                mon = rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */
  85                day = rtc_tm.tm_mday;
  86                hrs = rtc_tm.tm_hour;
  87                min = rtc_tm.tm_min;
  88                sec = rtc_tm.tm_sec;
  89
  90                leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
  91
  92                if ((mon > 12) || (day == 0))
  93                        return -EINVAL;
  94
  95                if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
  96                        return -EINVAL;
  97
  98                if ((hrs >= 24) || (min >= 60) || (sec >= 60))
  99                        return -EINVAL;
 100
 101                if (yrs >= 2070)
 102                        return -EINVAL;
 103
 104                local_irq_save(flags);
 105                rtc->ctrl     = RTC_WRITE;
 106
 107                rtc->bcd_sec  = bin2bcd(sec);
 108                rtc->bcd_min  = bin2bcd(min);
 109                rtc->bcd_hr   = bin2bcd(hrs);
 110                rtc->bcd_dom  = bin2bcd(day);
 111                rtc->bcd_mth  = bin2bcd(mon);
 112                rtc->bcd_year = bin2bcd(yrs%100);
 113
 114                rtc->ctrl     = 0;
 115                local_irq_restore(flags);
 116                return 0;
 117        }
 118        default:
 119                return -EINVAL;
 120        }
 121}
 122
 123/*
 124 *      We enforce only one user at a time here with the open/close.
 125 *      Also clear the previous interrupt data on an open, and clean
 126 *      up things on a close.
 127 */
 128
 129static int rtc_open(struct inode *inode, struct file *file)
 130{
 131        lock_kernel();
 132        if( !atomic_dec_and_test(&rtc_ready) )
 133        {
 134                atomic_inc( &rtc_ready );
 135                unlock_kernel();
 136                return -EBUSY;
 137        }
 138        unlock_kernel();
 139
 140        return 0;
 141}
 142
 143static int rtc_release(struct inode *inode, struct file *file)
 144{
 145        atomic_inc( &rtc_ready );
 146        return 0;
 147}
 148
 149/*
 150 *      The various file operations we support.
 151 */
 152
 153static const struct file_operations rtc_fops = {
 154        .ioctl =        rtc_ioctl,
 155        .open =         rtc_open,
 156        .release =      rtc_release,
 157};
 158
 159static struct miscdevice rtc_dev=
 160{
 161        .minor =        RTC_MINOR,
 162        .name =         "rtc",
 163        .fops =         &rtc_fops
 164};
 165
 166static int __init rtc_MK48T08_init(void)
 167{
 168        if (!MACH_IS_MVME16x)
 169                return -ENODEV;
 170
 171        printk(KERN_INFO "MK48T08 Real Time Clock Driver v%s\n", RTC_VERSION);
 172        return misc_register(&rtc_dev);
 173}
 174module_init(rtc_MK48T08_init);
 175