LXR linux/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
  36static unsigned char days_in_mo[] =
  37{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  38
  39static char rtc_status;
  40
  41static 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
 141static 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
 154static 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
 166static const struct file_operations rtc_fops = {
 167        .ioctl =        rtc_ioctl,
 168        .open =         rtc_open,
 169        .release =      rtc_release,
 170};
 171
 172static struct miscdevice rtc_dev = {
 173        .minor =        RTC_MINOR,
 174        .name =         "rtc",
 175        .fops =         &rtc_fops
 176};
 177
 178static 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}
 186module_init(rtc_DP8570A_init);
 187