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