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/malloc.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 <asm/bvme6000hw.h>
  19
  20 #include <asm/io.h>
  21 #include <asm/uaccess.h>
  22 #include <asm/system.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 #define BCD2BIN(val) (((val)&15) + ((val)>>4)*10)
  33 #define BIN2BCD(val) ((((val)/10)<<4) + (val)%10)
  34
  35 static unsigned char days_in_mo[] =
  36 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  37
  38 static char rtc_status = 0;
  39
  40 static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
  41                      unsigned long arg)
  42 {
  43         volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
  44         unsigned char msr;
  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                 save_flags(flags);
  52                 cli();
  53                 /* Ensure clock and real-time-mode-register are accessible */
  54                 msr = rtc->msr & 0xc0;
  55                 rtc->msr = 0x40;
  56                 do {
  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                 } while (wtime.tm_sec != BCD2BIN(rtc->bcd_sec));
  67                 rtc->msr = msr;
  68                 restore_flags(flags);
  69                 return copy_to_user((void *)arg, &wtime, sizeof wtime) ?
  70                                                                 -EFAULT : 0;
  71         }
  72         case RTC_SET_TIME:      /* Set the RTC */
  73         {
  74                 unsigned char leap_yr;
  75                 struct rtc_time rtc_tm;
  76
  77                 if (!suser())
  78                         return -EACCES;
  79
  80                 if (copy_from_user(&rtc_tm, (struct rtc_time*)arg,
  81                                    sizeof(struct rtc_time)))
  82                         return -EFAULT;
  83
  84                 leap_yr = ((!(rtc_tm.tm_year % 4) && (rtc_tm.tm_year % 100)) || !(rtc_tm.tm_year % 400));
  85
  86                 if ((rtc_tm.tm_mon > 12) || (rtc_tm.tm_mday == 0))
  87                         return -EINVAL;
  88
  89                 if (rtc_tm.tm_mday > (days_in_mo[rtc_tm.tm_mon] + ((rtc_tm.tm_mon == 2) && leap_yr)))
  90                         return -EINVAL;
  91
  92                 if ((rtc_tm.tm_hour >= 24) || (rtc_tm.tm_min >= 60) || (rtc_tm.tm_sec >= 60))
  93                         return -EINVAL;
  94
  95                 save_flags(flags);
  96                 cli();
  97                 /* Ensure clock and real-time-mode-register are accessible */
  98                 msr = rtc->msr & 0xc0;
  99                 rtc->msr = 0x40;
 100
 101                 rtc->t0cr_rtmr = rtc_tm.tm_year%4;
 102                 rtc->bcd_tenms = 0;
 103                 rtc->bcd_sec = BIN2BCD(rtc_tm.tm_sec);
 104                 rtc->bcd_min = BIN2BCD(rtc_tm.tm_min);
 105                 rtc->bcd_hr  = BIN2BCD(rtc_tm.tm_hour);
 106                 rtc->bcd_dom = BIN2BCD(rtc_tm.tm_mday);
 107                 rtc->bcd_mth = BIN2BCD(rtc_tm.tm_mon + 1);
 108                 rtc->bcd_year = BIN2BCD(rtc_tm.tm_year%100);
 109                 if (rtc_tm.tm_wday >= 0)
 110                         rtc->bcd_dow = BIN2BCD(rtc_tm.tm_wday+1);
 111                 rtc->t0cr_rtmr = rtc_tm.tm_year%4 | 0x08;
 112
 113                 rtc->msr = msr;
 114                 restore_flags(flags);
 115                 return 0;
 116         }
 117         default:
 118                 return -EINVAL;
 119         }
 120 }
 121
 122 /*
 123  *      We enforce only one user at a time here with the open/close.
 124  *      Also clear the previous interrupt data on an open, and clean
 125  *      up things on a close.
 126  */
 127
 128 static int rtc_open(struct inode *inode, struct file *file)
 129 {
 130         if(rtc_status)
 131                 return -EBUSY;
 132
 133         rtc_status = 1;
 134         return 0;
 135 }
 136
 137 static int rtc_release(struct inode *inode, struct file *file)
 138 {
 139         rtc_status = 0;
 140         return 0;
 141 }
 142
 143 /*
 144  *      The various file operations we support.
 145  */
 146
 147 static struct file_operations rtc_fops = {
 148         NULL,
 149         NULL,
 150         NULL,           /* No write */
 151         NULL,           /* No readdir */
 152         NULL,
 153         rtc_ioctl,
 154         NULL,           /* No mmap */
 155         rtc_open,
 156         NULL,           /* flush */
 157         rtc_release
 158 };
 159
 160 static struct miscdevice rtc_dev=
 161 {
 162         RTC_MINOR,
 163         "rtc",
 164         &rtc_fops
 165 };
 166
 167 __initfunc(int rtc_DP8570A_init(void))
 168 {
 169         if (!MACH_IS_BVME6000)
 170                 return -ENODEV;
 171
 172         printk(KERN_INFO "DP8570A Real Time Clock Driver v%s\n", RTC_VERSION);
 173         misc_register(&rtc_dev);
 174         return 0;
 175 }
 176