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/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/smp_lock.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 #define BCD2BIN(val) (((val)&15) + ((val)>>4)*10)
  35 #define BIN2BCD(val) ((((val)/10)<<4) + (val)%10)
  36
  37 static const unsigned char days_in_mo[] =
  38 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  39
  40 static atomic_t rtc_ready = ATOMIC_INIT(1);
  41
  42 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
  43                      unsigned long arg)
  44 {
  45         volatile MK48T08ptr_t rtc = (MK48T08ptr_t)MVME_RTC_BASE;
  46         unsigned long flags;
  47         struct rtc_time wtime;
  48         void __user *argp = (void __user *)arg;
  49
  50         switch (cmd) {
  51         case RTC_RD_TIME:       /* Read the time/date from RTC  */
  52         {
  53                 local_irq_save(flags);
  54                 /* Ensure clock and real-time-mode-register are accessible */
  55                 rtc->ctrl = RTC_READ;
  56                 memset(&wtime, 0, sizeof(struct rtc_time));
  57                 wtime.tm_sec =  BCD2BIN(rtc->bcd_sec);
  58                 wtime.tm_min =  BCD2BIN(rtc->bcd_min);
  59                 wtime.tm_hour = BCD2BIN(rtc->bcd_hr);
  60                 wtime.tm_mday =  BCD2BIN(rtc->bcd_dom);
  61                 wtime.tm_mon =  BCD2BIN(rtc->bcd_mth)-1;
  62                 wtime.tm_year = BCD2BIN(rtc->bcd_year);
  63                 if (wtime.tm_year < 70)
  64                         wtime.tm_year += 100;
  65                 wtime.tm_wday = BCD2BIN(rtc->bcd_dow)-1;
  66                 rtc->ctrl = 0;
  67                 local_irq_restore(flags);
  68                 return copy_to_user(argp, &wtime, sizeof wtime) ?
  69                                                                 -EFAULT : 0;
  70         }
  71         case RTC_SET_TIME:      /* Set the RTC */
  72         {
  73                 struct rtc_time rtc_tm;
  74                 unsigned char mon, day, hrs, min, sec, leap_yr;
  75                 unsigned int yrs;
  76
  77                 if (!capable(CAP_SYS_ADMIN))
  78                         return -EACCES;
  79
  80                 if (copy_from_user(&rtc_tm, argp, sizeof(struct rtc_time)))
  81                         return -EFAULT;
  82
  83                 yrs = rtc_tm.tm_year;
  84                 if (yrs < 1900)
  85                         yrs += 1900;
  86                 mon = rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */
  87                 day = rtc_tm.tm_mday;
  88                 hrs = rtc_tm.tm_hour;
  89                 min = rtc_tm.tm_min;
  90                 sec = rtc_tm.tm_sec;
  91
  92                 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
  93
  94                 if ((mon > 12) || (day == 0))
  95                         return -EINVAL;
  96
  97                 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
  98                         return -EINVAL;
  99
 100                 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
 101                         return -EINVAL;
 102
 103                 if (yrs >= 2070)
 104                         return -EINVAL;
 105
 106                 local_irq_save(flags);
 107                 rtc->ctrl     = RTC_WRITE;
 108
 109                 rtc->bcd_sec  = BIN2BCD(sec);
 110                 rtc->bcd_min  = BIN2BCD(min);
 111                 rtc->bcd_hr   = BIN2BCD(hrs);
 112                 rtc->bcd_dom  = BIN2BCD(day);
 113                 rtc->bcd_mth  = BIN2BCD(mon);
 114                 rtc->bcd_year = BIN2BCD(yrs%100);
 115
 116                 rtc->ctrl     = 0;
 117                 local_irq_restore(flags);
 118                 return 0;
 119         }
 120         default:
 121                 return -EINVAL;
 122         }
 123 }
 124
 125 /*
 126  *      We enforce only one user at a time here with the open/close.
 127  *      Also clear the previous interrupt data on an open, and clean
 128  *      up things on a close.
 129  */
 130
 131 static int rtc_open(struct inode *inode, struct file *file)
 132 {
 133         if( !atomic_dec_and_test(&rtc_ready) )
 134         {
 135                 atomic_inc( &rtc_ready );
 136                 return -EBUSY;
 137         }
 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 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);