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
  35 static const unsigned char days_in_mo[] =
  36 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  37
  38 static atomic_t rtc_ready = ATOMIC_INIT(1);
  39
  40 static 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
 129 static 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
 143 static 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
 153 static const struct file_operations rtc_fops = {
 154         .ioctl =        rtc_ioctl,
 155         .open =         rtc_open,
 156         .release =      rtc_release,
 157 };
 158
 159 static struct miscdevice rtc_dev=
 160 {
 161         .minor =        RTC_MINOR,
 162         .name =         "rtc",
 163         .fops =         &rtc_fops
 164 };
 165
 166 static 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 }
 174 module_init(rtc_MK48T08_init);