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/*

 *      Real Time Clock interface for Linux on the BVME6000

 *

 * Based on the PC driver by Paul Gortmaker.

 */

#define RTC_VERSION             "1.00"

#include <linux/types.h>

#include <linux/errno.h>

#include <linux/miscdevice.h>

#include <linux/slab.h>

#include <linux/ioport.h>

#include <linux/fcntl.h>

#include <linux/init.h>

#include <linux/poll.h>

#include <linux/rtc.h>  /* For struct rtc_time and ioctls, etc */

#include <linux/smp_lock.h>

#include <asm/bvme6000hw.h>

#include <asm/io.h>

#include <asm/uaccess.h>

#include <asm/system.h>

#include <asm/setup.h>

/*

 *      We sponge a minor off of the misc major. No need slurping

 *      up another valuable major dev number for this. If you add

 *      an ioctl, make sure you don't conflict with SPARC's RTC

 *      ioctls.

 */

#define BCD2BIN(val) (((val)&15) + ((val)>>4)*10)

#define BIN2BCD(val) ((((val)/10)<<4) + (val)%10)

static unsigned char days_in_mo[] =

{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

static char rtc_status = 0;

static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,

                     unsigned long arg)

{

        volatile RtcPtr_t rtc = (RtcPtr_t)BVME_RTC_BASE;

        unsigned char msr;

        unsigned long flags;

        struct rtc_time wtime;

        switch (cmd) {

        case RTC_RD_TIME:       /* Read the time/date from RTC  */

        {

                save_flags(flags);

                cli();

                /* Ensure clock and real-time-mode-register are accessible */

                msr = rtc->msr & 0xc0;

                rtc->msr = 0x40;

                memset(&wtime, 0, sizeof(struct rtc_time));

                do {

                        wtime.tm_sec =  BCD2BIN(rtc->bcd_sec);

                        wtime.tm_min =  BCD2BIN(rtc->bcd_min);

                        wtime.tm_hour = BCD2BIN(rtc->bcd_hr);

                        wtime.tm_mday =  BCD2BIN(rtc->bcd_dom);

                        wtime.tm_mon =  BCD2BIN(rtc->bcd_mth)-1;

                        wtime.tm_year = BCD2BIN(rtc->bcd_year);

                        if (wtime.tm_year < 70)

                                wtime.tm_year += 100;

                        wtime.tm_wday = BCD2BIN(rtc->bcd_dow)-1;

                } while (wtime.tm_sec != BCD2BIN(rtc->bcd_sec));

                rtc->msr = msr;

                restore_flags(flags);

                return copy_to_user((void *)arg, &wtime, sizeof wtime) ?

                                                                -EFAULT : 0;

        }

        case RTC_SET_TIME:      /* Set the RTC */

        {

                struct rtc_time rtc_tm;

                unsigned char mon, day, hrs, min, sec, leap_yr;

                unsigned int yrs;

                if (!capable(CAP_SYS_ADMIN))

                        return -EACCES;

                if (copy_from_user(&rtc_tm, (struct rtc_time*)arg,

                                   sizeof(struct rtc_time)))

                        return -EFAULT;

                yrs = rtc_tm.tm_year;

                if (yrs < 1900)

                        yrs += 1900;

                mon = rtc_tm.tm_mon + 1;   /* tm_mon starts at zero */

                day = rtc_tm.tm_mday;

                hrs = rtc_tm.tm_hour;

                min = rtc_tm.tm_min;

                sec = rtc_tm.tm_sec;

                leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));

                if ((mon > 12) || (mon < 1) || (day == 0))

                        return -EINVAL;

                if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))

                        return -EINVAL;

                if ((hrs >= 24) || (min >= 60) || (sec >= 60))

                        return -EINVAL;

                if (yrs >= 2070)

                        return -EINVAL;

                save_flags(flags);

                cli();

                /* Ensure clock and real-time-mode-register are accessible */

                msr = rtc->msr & 0xc0;

                rtc->msr = 0x40;

                rtc->t0cr_rtmr = yrs%4;

                rtc->bcd_tenms = 0;

                rtc->bcd_sec   = BIN2BCD(sec);

                rtc->bcd_min   = BIN2BCD(min);

                rtc->bcd_hr    = BIN2BCD(hrs);

                rtc->bcd_dom   = BIN2BCD(day);

                rtc->bcd_mth   = BIN2BCD(mon);

                rtc->bcd_year  = BIN2BCD(yrs%100);

                if (rtc_tm.tm_wday >= 0)

                        rtc->bcd_dow = BIN2BCD(rtc_tm.tm_wday+1);

                rtc->t0cr_rtmr = yrs%4 | 0x08;

                rtc->msr = msr;

                restore_flags(flags);

                return 0;

        }

        default:

                return -EINVAL;

        }

}

/*

 *      We enforce only one user at a time here with the open/close.

 *      Also clear the previous interrupt data on an open, and clean

 *      up things on a close.

 */

static int rtc_open(struct inode *inode, struct file *file)

{

        if(rtc_status)

                return -EBUSY;

        rtc_status = 1;

        return 0;

}

static int rtc_release(struct inode *inode, struct file *file)

{

        lock_kernel();

        rtc_status = 0;

        unlock_kernel();

        return 0;

}

/*

 *      The various file operations we support.

 */

static struct file_operations rtc_fops = {

        ioctl:          rtc_ioctl,

        open:           rtc_open,

        release:        rtc_release,

};

static struct miscdevice rtc_dev=

{

        RTC_MINOR,

        "rtc",

        &rtc_fops

};

int __init rtc_DP8570A_init(void)

{

        if (!MACH_IS_BVME6000)

                return -ENODEV;

        printk(KERN_INFO "DP8570A Real Time Clock Driver v%s\n", RTC_VERSION);

        return misc_register(&rtc_dev);

}