arch/m68k/bvme6000/rtc.c

   1 /*
   2  *      Real Time Clock interface for Linux on the BVME6000
   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/module.h>
  20 #include <linux/mc146818rtc.h>  /* For struct rtc_time and ioctls, etc */
  21 #include <linux/bcd.h>
  22 #include <asm/bvme6000hw.h>
  23
  24 #include <asm/io.h>
  25 #include <asm/uaccess.h>
  26 #include <asm/system.h>
  27 #include <asm/setup.h>
  28
  29 /*
  30  *      We sponge a minor off of the misc major. No need slurping
  31  *      up another valuable major dev number for this. If you add
  32  *      an ioctl, make sure you don't conflict with SPARC's RTC
  33  *      ioctls.
  34  */
  35
  36 static unsigned char days_in_mo[] =
  37 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  38
  39 static char rtc_status;
  40
  41 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
  42                      unsigned long arg)
  43 {
  44         volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
  45         unsigned char msr;
  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                 msr = rtc->msr & 0xc0;
  56                 rtc->msr = 0x40;
  57                 memset(&wtime, 0, sizeof(struct rtc_time));
  58                 do {
  59                         wtime.tm_sec =  bcd2bin(rtc->bcd_sec);
  60                         wtime.tm_min =  bcd2bin(rtc->bcd_min);
  61                         wtime.tm_hour = bcd2bin(rtc->bcd_hr);
  62                         wtime.tm_mday =  bcd2bin(rtc->bcd_dom);
  63                         wtime.tm_mon =  bcd2bin(rtc->bcd_mth)-1;
  64                         wtime.tm_year = bcd2bin(rtc->bcd_year);
  65                         if (wtime.tm_year < 70)
  66                                 wtime.tm_year += 100;
  67                         wtime.tm_wday = bcd2bin(rtc->bcd_dow)-1;
  68                 } while (wtime.tm_sec != bcd2bin(rtc->bcd_sec));
  69                 rtc->msr = msr;
  70                 local_irq_restore(flags);
  71                 return copy_to_user(argp, &wtime, sizeof wtime) ?
  72                                                                 -EFAULT : 0;
  73         }
  74         case RTC_SET_TIME:      /* Set the RTC */
  75         {
  76                 struct rtc_time rtc_tm;
  77                 unsigned char mon, day, hrs, min, sec, leap_yr;
  78                 unsigned int yrs;
  79
  80                 if (!capable(CAP_SYS_ADMIN))
  81                         return -EACCES;
  82
  83                 if (copy_from_user(&rtc_tm, argp, sizeof(struct rtc_time)))
  84                         return -EFAULT;
  85
  86                 yrs = rtc_tm.tm_year;
  87                 if (yrs < 1900)
  88                         yrs += 1900;
  89                 mon = rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */
  90                 day = rtc_tm.tm_mday;
  91                 hrs = rtc_tm.tm_hour;
  92                 min = rtc_tm.tm_min;
  93                 sec = rtc_tm.tm_sec;
  94
  95                 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
  96
  97                 if ((mon > 12) || (mon < 1) || (day == 0))
  98                         return -EINVAL;
  99
 100                 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
 101                         return -EINVAL;
 102
 103                 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
 104                         return -EINVAL;
 105
 106                 if (yrs >= 2070)
 107                         return -EINVAL;
 108
 109                 local_irq_save(flags);
 110                 /* Ensure clock and real-time-mode-register are accessible */
 111                 msr = rtc->msr & 0xc0;
 112                 rtc->msr = 0x40;
 113
 114                 rtc->t0cr_rtmr = yrs%4;
 115                 rtc->bcd_tenms = 0;
 116                 rtc->bcd_sec   = bin2bcd(sec);
 117                 rtc->bcd_min   = bin2bcd(min);
 118                 rtc->bcd_hr    = bin2bcd(hrs);
 119                 rtc->bcd_dom   = bin2bcd(day);
 120                 rtc->bcd_mth   = bin2bcd(mon);
 121                 rtc->bcd_year  = bin2bcd(yrs%100);
 122                 if (rtc_tm.tm_wday >= 0)
 123                         rtc->bcd_dow = bin2bcd(rtc_tm.tm_wday+1);
 124                 rtc->t0cr_rtmr = yrs%4 | 0x08;
 125
 126                 rtc->msr = msr;
 127                 local_irq_restore(flags);
 128                 return 0;
 129         }
 130         default:
 131                 return -EINVAL;
 132         }
 133 }
 134
 135 /*
 136  *      We enforce only one user at a time here with the open/close.
 137  *      Also clear the previous interrupt data on an open, and clean
 138  *      up things on a close.
 139  */
 140
 141 static int rtc_open(struct inode *inode, struct file *file)
 142 {
 143         lock_kernel();
 144         if(rtc_status) {
 145                 unlock_kernel();
 146                 return -EBUSY;
 147         }
 148
 149         rtc_status = 1;
 150         unlock_kernel();
 151         return 0;
 152 }
 153
 154 static int rtc_release(struct inode *inode, struct file *file)
 155 {
 156         lock_kernel();
 157         rtc_status = 0;
 158         unlock_kernel();
 159         return 0;
 160 }
 161
 162 /*
 163  *      The various file operations we support.
 164  */
 165
 166 static const struct file_operations rtc_fops = {
 167         .ioctl =        rtc_ioctl,
 168         .open =         rtc_open,
 169         .release =      rtc_release,
 170 };
 171
 172 static struct miscdevice rtc_dev = {
 173         .minor =        RTC_MINOR,
 174         .name =         "rtc",
 175         .fops =         &rtc_fops
 176 };
 177
 178 static int __init rtc_DP8570A_init(void)
 179 {
 180         if (!MACH_IS_BVME6000)
 181                 return -ENODEV;
 182
 183         printk(KERN_INFO "DP8570A Real Time Clock Driver v%s\n", RTC_VERSION);
 184         return misc_register(&rtc_dev);
 185 }
 186 module_init(rtc_DP8570A_init);