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/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/module.h>
  18#include <linux/mc146818rtc.h>  /* For struct rtc_time and ioctls, etc */
  19#include <linux/bcd.h>
  20#include <asm/bvme6000hw.h>
  21
  22#include <asm/io.h>
  23#include <asm/uaccess.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
  33static unsigned char days_in_mo[] =
  34{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
  35
  36static atomic_t rtc_status = ATOMIC_INIT(1);
  37
  38static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
  39{
  40        volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;
  41        unsigned char msr;
  42        unsigned long flags;
  43        struct rtc_time wtime;
  44        void __user *argp = (void __user *)arg;
  45
  46        switch (cmd) {
  47        case RTC_RD_TIME:       /* Read the time/date from RTC  */
  48        {
  49                local_irq_save(flags);
  50                /* Ensure clock and real-time-mode-register are accessible */
  51                msr = rtc->msr & 0xc0;
  52                rtc->msr = 0x40;
  53                memset(&wtime, 0, sizeof(struct rtc_time));
  54                do {
  55                        wtime.tm_sec =  bcd2bin(rtc->bcd_sec);
  56                        wtime.tm_min =  bcd2bin(rtc->bcd_min);
  57                        wtime.tm_hour = bcd2bin(rtc->bcd_hr);
  58                        wtime.tm_mday =  bcd2bin(rtc->bcd_dom);
  59                        wtime.tm_mon =  bcd2bin(rtc->bcd_mth)-1;
  60                        wtime.tm_year = bcd2bin(rtc->bcd_year);
  61                        if (wtime.tm_year < 70)
  62                                wtime.tm_year += 100;
  63                        wtime.tm_wday = bcd2bin(rtc->bcd_dow)-1;
  64                } while (wtime.tm_sec != bcd2bin(rtc->bcd_sec));
  65                rtc->msr = msr;
  66                local_irq_restore(flags);
  67                return copy_to_user(argp, &wtime, sizeof wtime) ?
  68                                                                -EFAULT : 0;
  69        }
  70        case RTC_SET_TIME:      /* Set the RTC */
  71        {
  72                struct rtc_time rtc_tm;
  73                unsigned char mon, day, hrs, min, sec, leap_yr;
  74                unsigned int yrs;
  75
  76                if (!capable(CAP_SYS_ADMIN))
  77                        return -EACCES;
  78
  79                if (copy_from_user(&rtc_tm, argp, sizeof(struct rtc_time)))
  80                        return -EFAULT;
  81
  82                yrs = rtc_tm.tm_year;
  83                if (yrs < 1900)
  84                        yrs += 1900;
  85                mon = rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */
  86                day = rtc_tm.tm_mday;
  87                hrs = rtc_tm.tm_hour;
  88                min = rtc_tm.tm_min;
  89                sec = rtc_tm.tm_sec;
  90
  91                leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
  92
  93                if ((mon > 12) || (mon < 1) || (day == 0))
  94                        return -EINVAL;
  95
  96                if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
  97                        return -EINVAL;
  98
  99                if ((hrs >= 24) || (min >= 60) || (sec >= 60))
 100                        return -EINVAL;
 101
 102                if (yrs >= 2070)
 103                        return -EINVAL;
 104
 105                local_irq_save(flags);
 106                /* Ensure clock and real-time-mode-register are accessible */
 107                msr = rtc->msr & 0xc0;
 108                rtc->msr = 0x40;
 109
 110                rtc->t0cr_rtmr = yrs%4;
 111                rtc->bcd_tenms = 0;
 112                rtc->bcd_sec   = bin2bcd(sec);
 113                rtc->bcd_min   = bin2bcd(min);
 114                rtc->bcd_hr    = bin2bcd(hrs);
 115                rtc->bcd_dom   = bin2bcd(day);
 116                rtc->bcd_mth   = bin2bcd(mon);
 117                rtc->bcd_year  = bin2bcd(yrs%100);
 118                if (rtc_tm.tm_wday >= 0)
 119                        rtc->bcd_dow = bin2bcd(rtc_tm.tm_wday+1);
 120                rtc->t0cr_rtmr = yrs%4 | 0x08;
 121
 122                rtc->msr = msr;
 123                local_irq_restore(flags);
 124                return 0;
 125        }
 126        default:
 127                return -EINVAL;
 128        }
 129}
 130
 131/*
 132 * We enforce only one user at a time here with the open/close.
 133 */
 134static int rtc_open(struct inode *inode, struct file *file)
 135{
 136        if (!atomic_dec_and_test(&rtc_status)) {
 137                atomic_inc(&rtc_status);
 138                return -EBUSY;
 139        }
 140        return 0;
 141}
 142
 143static int rtc_release(struct inode *inode, struct file *file)
 144{
 145        atomic_inc(&rtc_status);
 146        return 0;
 147}
 148
 149/*
 150 *      The various file operations we support.
 151 */
 152
 153static const struct file_operations rtc_fops = {
 154        .unlocked_ioctl = rtc_ioctl,
 155        .open           = rtc_open,
 156        .release        = rtc_release,
 157        .llseek         = noop_llseek,
 158};
 159
 160static struct miscdevice rtc_dev = {
 161        .minor =        RTC_MINOR,
 162        .name =         "rtc",
 163        .fops =         &rtc_fops
 164};
 165
 166static int __init rtc_DP8570A_init(void)
 167{
 168        if (!MACH_IS_BVME6000)
 169                return -ENODEV;
 170
 171        printk(KERN_INFO "DP8570A Real Time Clock Driver v%s\n", RTC_VERSION);
 172        return misc_register(&rtc_dev);
 173}
 174module_init(rtc_DP8570A_init);
 175