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/ioport.h>
  14 #include <linux/fcntl.h>
  15 #include <linux/init.h>
  16 #include <linux/poll.h>
  17 #include <linux/mc146818rtc.h>  /* For struct rtc_time and ioctls, etc */
  18 #include <linux/smp_lock.h>
  19 #include <asm/mvme16xhw.h>
  20
  21 #include <asm/io.h>
  22 #include <asm/uaccess.h>
  23 #include <asm/system.h>
  24 #include <asm/setup.h>
  25
  26 /*
  27  *      We sponge a minor off of the misc major. No need slurping
  28  *      up another valuable major dev number for this. If you add
  29  *      an ioctl, make sure you don't conflict with SPARC's RTC
  30  *      ioctls.
  31  */
  32
  33 #define BCD2BIN(val) (((val)&15) + ((val)>>4)*10)
  34 #define BIN2BCD(val) ((((val)/10)<<4) + (val)%10)
  35
  36 static const unsigned char days_in_mo[] =
  37 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  38
  39 static atomic_t rtc_ready = ATOMIC_INIT(1);
  40
  41 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
  42                      unsigned long arg)
  43 {
  44         volatile MK48T08ptr_t rtc = (MK48T08ptr_t)MVME_RTC_BASE;
  45         unsigned long flags;
  46         struct rtc_time wtime;
  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((void *)arg, &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, (struct rtc_time*)arg,
  79                                    sizeof(struct rtc_time)))
  80                         return -EFAULT;
  81
  82                 yrs = rtc_tm.tm_year;
  83                 if (yrs < 1900)
  84                         yrs += 1900;
  85                 mon = rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */
  86                 day = rtc_tm.tm_mday;
  87                 hrs = rtc_tm.tm_hour;
  88                 min = rtc_tm.tm_min;
  89                 sec = rtc_tm.tm_sec;
  90
  91                 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
  92
  93                 if ((mon > 12) || (day == 0))
  94                         return -EINVAL;
  95
  96                 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
  97                         return -EINVAL;
  98
  99                 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
 100                         return -EINVAL;
 101
 102                 if (yrs >= 2070)
 103                         return -EINVAL;
 104
 105                 local_irq_save(flags);
 106                 rtc->ctrl     = RTC_WRITE;
 107
 108                 rtc->bcd_sec  = BIN2BCD(sec);
 109                 rtc->bcd_min  = BIN2BCD(min);
 110                 rtc->bcd_hr   = BIN2BCD(hrs);
 111                 rtc->bcd_dom  = BIN2BCD(day);
 112                 rtc->bcd_mth  = BIN2BCD(mon);
 113                 rtc->bcd_year = BIN2BCD(yrs%100);
 114
 115                 rtc->ctrl     = 0;
 116                 local_irq_restore(flags);
 117                 return 0;
 118         }
 119         default:
 120                 return -EINVAL;
 121         }
 122 }
 123
 124 /*
 125  *      We enforce only one user at a time here with the open/close.
 126  *      Also clear the previous interrupt data on an open, and clean
 127  *      up things on a close.
 128  */
 129
 130 static int rtc_open(struct inode *inode, struct file *file)
 131 {
 132         if( !atomic_dec_and_test(&rtc_ready) )
 133         {
 134                 atomic_inc( &rtc_ready );
 135                 return -EBUSY;
 136         }
 137
 138         return 0;
 139 }
 140
 141 static int rtc_release(struct inode *inode, struct file *file)
 142 {
 143         atomic_inc( &rtc_ready );
 144         return 0;
 145 }
 146
 147 /*
 148  *      The various file operations we support.
 149  */
 150
 151 static struct file_operations rtc_fops = {
 152         .ioctl =        rtc_ioctl,
 153         .open =         rtc_open,
 154         .release =      rtc_release,
 155 };
 156
 157 static struct miscdevice rtc_dev=
 158 {
 159         .minor =        RTC_MINOR,
 160         .name =         "rtc",
 161         .fops =         &rtc_fops
 162 };
 163
 164 int __init rtc_MK48T08_init(void)
 165 {
 166         if (!MACH_IS_MVME16x)
 167                 return -ENODEV;
 168
 169         printk(KERN_INFO "MK48T08 Real Time Clock Driver v%s\n", RTC_VERSION);
 170         return misc_register(&rtc_dev);
 171 }
 172