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