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/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/mc146818rtc.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 <asm/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
  32static const unsigned char days_in_mo[] =
  33{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  34
  35static atomic_t rtc_ready = ATOMIC_INIT(1);
  36
  37static 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 */
 122static 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
 132static 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
 142static 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
 149static struct miscdevice rtc_dev=
 150{
 151        .minor =        RTC_MINOR,
 152        .name =         "rtc",
 153        .fops =         &rtc_fops
 154};
 155
 156static int __init rtc_MK48T08_init(void)
 157{
 158        if (!MACH_IS_MVME16x)
 159                return -ENODEV;
 160
 161        printk(KERN_INFO "MK48T08 Real Time Clock Driver v%s\n", RTC_VERSION);
 162        return misc_register(&rtc_dev);
 163}
 164module_init(rtc_MK48T08_init);
 165