LXR linux-old/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/rtc.h>  /* For struct rtc_time and ioctls, etc */
  18#include <linux/smp_lock.h>
  19#include <asm/bvme6000hw.h>
  20
  21#include <asm/io.h>
  22#include <asm/uaccess.h>
  23#include <asm/system.h>
  24#include <asm/setup.h>
  25
  26/*
  27 *      We sponge a minor off of the misc major. No need slurping
  28 *      up another valuable major dev number for this. If you add
  29 *      an ioctl, make sure you don't conflict with SPARC's RTC
  30 *      ioctls.
  31 */
  32
  33#define BCD2BIN(val) (((val)&15) + ((val)>>4)*10)
  34#define BIN2BCD(val) ((((val)/10)<<4) + (val)%10)
  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 = 0;
  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
  49        switch (cmd) {
  50        case RTC_RD_TIME:       /* Read the time/date from RTC  */
  51        {
  52                save_flags(flags);
  53                cli();
  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                restore_flags(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                save_flags(flags);
 111                cli();
 112                /* Ensure clock and real-time-mode-register are accessible */
 113                msr = rtc->msr & 0xc0;
 114                rtc->msr = 0x40;
 115
 116                rtc->t0cr_rtmr = yrs%4;
 117                rtc->bcd_tenms = 0;
 118                rtc->bcd_sec   = BIN2BCD(sec);
 119                rtc->bcd_min   = BIN2BCD(min);
 120                rtc->bcd_hr    = BIN2BCD(hrs);
 121                rtc->bcd_dom   = BIN2BCD(day);
 122                rtc->bcd_mth   = BIN2BCD(mon);
 123                rtc->bcd_year  = BIN2BCD(yrs%100);
 124                if (rtc_tm.tm_wday >= 0)
 125                        rtc->bcd_dow = BIN2BCD(rtc_tm.tm_wday+1);
 126                rtc->t0cr_rtmr = yrs%4 | 0x08;
 127
 128                rtc->msr = msr;
 129                restore_flags(flags);
 130                return 0;
 131        }
 132        default:
 133                return -EINVAL;
 134        }
 135}
 136
 137/*
 138 *      We enforce only one user at a time here with the open/close.
 139 *      Also clear the previous interrupt data on an open, and clean
 140 *      up things on a close.
 141 */
 142
 143static int rtc_open(struct inode *inode, struct file *file)
 144{
 145        if(rtc_status)
 146                return -EBUSY;
 147
 148        rtc_status = 1;
 149        return 0;
 150}
 151
 152static int rtc_release(struct inode *inode, struct file *file)
 153{
 154        lock_kernel();
 155        rtc_status = 0;
 156        unlock_kernel();
 157        return 0;
 158}
 159
 160/*
 161 *      The various file operations we support.
 162 */
 163
 164static struct file_operations rtc_fops = {
 165        ioctl:          rtc_ioctl,
 166        open:           rtc_open,
 167        release:        rtc_release,
 168};
 169
 170static struct miscdevice rtc_dev=
 171{
 172        RTC_MINOR,
 173        "rtc",
 174        &rtc_fops
 175};
 176
 177int __init rtc_DP8570A_init(void)
 178{
 179        if (!MACH_IS_BVME6000)
 180                return -ENODEV;
 181
 182        printk(KERN_INFO "DP8570A Real Time Clock Driver v%s\n", RTC_VERSION);
 183        return misc_register(&rtc_dev);
 184}
 185
 186