LXR linux/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/bcd.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
  34static const unsigned char days_in_mo[] =
  35{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  36
  37static atomic_t rtc_ready = ATOMIC_INIT(1);
  38
  39static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
  40                     unsigned long arg)
  41{
  42        volatile MK48T08ptr_t rtc = (MK48T08ptr_t)MVME_RTC_BASE;
  43        unsigned long flags;
  44        struct rtc_time wtime;
  45        void __user *argp = (void __user *)arg;
  46
  47        switch (cmd) {
  48        case RTC_RD_TIME:       /* Read the time/date from RTC  */
  49        {
  50                local_irq_save(flags);
  51                /* Ensure clock and real-time-mode-register are accessible */
  52                rtc->ctrl = RTC_READ;
  53                memset(&wtime, 0, sizeof(struct rtc_time));
  54                wtime.tm_sec =  BCD2BIN(rtc->bcd_sec);
  55                wtime.tm_min =  BCD2BIN(rtc->bcd_min);
  56                wtime.tm_hour = BCD2BIN(rtc->bcd_hr);
  57                wtime.tm_mday =  BCD2BIN(rtc->bcd_dom);
  58                wtime.tm_mon =  BCD2BIN(rtc->bcd_mth)-1;
  59                wtime.tm_year = BCD2BIN(rtc->bcd_year);
  60                if (wtime.tm_year < 70)
  61                        wtime.tm_year += 100;
  62                wtime.tm_wday = BCD2BIN(rtc->bcd_dow)-1;
  63                rtc->ctrl = 0;
  64                local_irq_restore(flags);
  65                return copy_to_user(argp, &wtime, sizeof wtime) ?
  66                                                                -EFAULT : 0;
  67        }
  68        case RTC_SET_TIME:      /* Set the RTC */
  69        {
  70                struct rtc_time rtc_tm;
  71                unsigned char mon, day, hrs, min, sec, leap_yr;
  72                unsigned int yrs;
  73
  74                if (!capable(CAP_SYS_ADMIN))
  75                        return -EACCES;
  76
  77                if (copy_from_user(&rtc_tm, argp, sizeof(struct rtc_time)))
  78                        return -EFAULT;
  79
  80                yrs = rtc_tm.tm_year;
  81                if (yrs < 1900)
  82                        yrs += 1900;
  83                mon = rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */
  84                day = rtc_tm.tm_mday;
  85                hrs = rtc_tm.tm_hour;
  86                min = rtc_tm.tm_min;
  87                sec = rtc_tm.tm_sec;
  88
  89                leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
  90
  91                if ((mon > 12) || (day == 0))
  92                        return -EINVAL;
  93
  94                if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
  95                        return -EINVAL;
  96
  97                if ((hrs >= 24) || (min >= 60) || (sec >= 60))
  98                        return -EINVAL;
  99
 100                if (yrs >= 2070)
 101                        return -EINVAL;
 102
 103                local_irq_save(flags);
 104                rtc->ctrl     = RTC_WRITE;
 105
 106                rtc->bcd_sec  = BIN2BCD(sec);
 107                rtc->bcd_min  = BIN2BCD(min);
 108                rtc->bcd_hr   = BIN2BCD(hrs);
 109                rtc->bcd_dom  = BIN2BCD(day);
 110                rtc->bcd_mth  = BIN2BCD(mon);
 111                rtc->bcd_year = BIN2BCD(yrs%100);
 112
 113                rtc->ctrl     = 0;
 114                local_irq_restore(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
 128static int rtc_open(struct inode *inode, struct file *file)
 129{
 130        if( !atomic_dec_and_test(&rtc_ready) )
 131        {
 132                atomic_inc( &rtc_ready );
 133                return -EBUSY;
 134        }
 135
 136        return 0;
 137}
 138
 139static int rtc_release(struct inode *inode, struct file *file)
 140{
 141        atomic_inc( &rtc_ready );
 142        return 0;
 143}
 144
 145/*
 146 *      The various file operations we support.
 147 */
 148
 149static const struct file_operations rtc_fops = {
 150        .ioctl =        rtc_ioctl,
 151        .open =         rtc_open,
 152        .release =      rtc_release,
 153};
 154
 155static struct miscdevice rtc_dev=
 156{
 157        .minor =        RTC_MINOR,
 158        .name =         "rtc",
 159        .fops =         &rtc_fops
 160};
 161
 162static int __init rtc_MK48T08_init(void)
 163{
 164        if (!MACH_IS_MVME16x)
 165                return -ENODEV;
 166
 167        printk(KERN_INFO "MK48T08 Real Time Clock Driver v%s\n", RTC_VERSION);
 168        return misc_register(&rtc_dev);
 169}
 170module_init(rtc_MK48T08_init);
 171