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/ioport.h>
  14 #include <linux/fcntl.h>
  15 #include <linux/init.h>
  16 #include <linux/poll.h>
  17 #include <linux/module.h>
  18 #include <linux/mc146818rtc.h>  /* For struct rtc_time and ioctls, etc */
  19 #include <linux/smp_lock.h>
  20 #include <asm/bvme6000hw.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 unsigned char days_in_mo[] =
  38 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  39
  40 static char rtc_status;
  41
  42 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
  43                      unsigned long arg)
  44 {
  45         volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
  46         unsigned char msr;
  47         unsigned long flags;
  48         struct rtc_time wtime;
  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((void *)arg, &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, (struct rtc_time*)arg,
  84                                    sizeof(struct rtc_time)))
  85                         return -EFAULT;
  86
  87                 yrs = rtc_tm.tm_year;
  88                 if (yrs < 1900)
  89                         yrs += 1900;
  90                 mon = rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */
  91                 day = rtc_tm.tm_mday;
  92                 hrs = rtc_tm.tm_hour;
  93                 min = rtc_tm.tm_min;
  94                 sec = rtc_tm.tm_sec;
  95
  96                 leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
  97
  98                 if ((mon > 12) || (mon < 1) || (day == 0))
  99                         return -EINVAL;
 100
 101                 if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
 102                         return -EINVAL;
 103
 104                 if ((hrs >= 24) || (min >= 60) || (sec >= 60))
 105                         return -EINVAL;
 106
 107                 if (yrs >= 2070)
 108                         return -EINVAL;
 109
 110                 local_irq_save(flags);
 111                 /* Ensure clock and real-time-mode-register are accessible */
 112                 msr = rtc->msr & 0xc0;
 113                 rtc->msr = 0x40;
 114
 115                 rtc->t0cr_rtmr = yrs%4;
 116                 rtc->bcd_tenms = 0;
 117                 rtc->bcd_sec   = BIN2BCD(sec);
 118                 rtc->bcd_min   = BIN2BCD(min);
 119                 rtc->bcd_hr    = BIN2BCD(hrs);
 120                 rtc->bcd_dom   = BIN2BCD(day);
 121                 rtc->bcd_mth   = BIN2BCD(mon);
 122                 rtc->bcd_year  = BIN2BCD(yrs%100);
 123                 if (rtc_tm.tm_wday >= 0)
 124                         rtc->bcd_dow = BIN2BCD(rtc_tm.tm_wday+1);
 125                 rtc->t0cr_rtmr = yrs%4 | 0x08;
 126
 127                 rtc->msr = msr;
 128                 local_irq_restore(flags);
 129                 return 0;
 130         }
 131         default:
 132                 return -EINVAL;
 133         }
 134 }
 135
 136 /*
 137  *      We enforce only one user at a time here with the open/close.
 138  *      Also clear the previous interrupt data on an open, and clean
 139  *      up things on a close.
 140  */
 141
 142 static int rtc_open(struct inode *inode, struct file *file)
 143 {
 144         if(rtc_status)
 145                 return -EBUSY;
 146
 147         rtc_status = 1;
 148         return 0;
 149 }
 150
 151 static int rtc_release(struct inode *inode, struct file *file)
 152 {
 153         lock_kernel();
 154         rtc_status = 0;
 155         unlock_kernel();
 156         return 0;
 157 }
 158
 159 /*
 160  *      The various file operations we support.
 161  */
 162
 163 static struct file_operations rtc_fops = {
 164         .ioctl =        rtc_ioctl,
 165         .open =         rtc_open,
 166         .release =      rtc_release,
 167 };
 168
 169 static struct miscdevice rtc_dev = {
 170         .minor =        RTC_MINOR,
 171         .name =         "rtc",
 172         .fops =         &rtc_fops
 173 };
 174
 175 static int __init rtc_DP8570A_init(void)
 176 {
 177         if (!MACH_IS_BVME6000)
 178                 return -ENODEV;
 179
 180         printk(KERN_INFO "DP8570A Real Time Clock Driver v%s\n", RTC_VERSION);
 181         return misc_register(&rtc_dev);
 182 }
 183 module_init(rtc_DP8570A_init);