rtc.c

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		return 0;
	}
#endif
	case RTC_ALM_READ:	/* Read the present alarm time */
	{
		/*
		 * This returns a struct rtc_time. Reading >= 0xc0
		 * means "don't care" or "match all". Only the tm_hour,
		 * tm_min, and tm_sec values are filled in.
		 */
		memset(&wtime, 0, sizeof(struct rtc_time));
		get_rtc_alm_time(&wtime);
		break; 
	}
	case RTC_ALM_SET:	/* Store a time into the alarm */
	{
		/*
		 * This expects a struct rtc_time. Writing 0xff means
		 * "don't care" or "match all". Only the tm_hour,
		 * tm_min and tm_sec are used.
		 */
		unsigned char hrs, min, sec;
		struct rtc_time alm_tm;

		if (copy_from_user(&alm_tm, (struct rtc_time __user *)arg,
				   sizeof(struct rtc_time)))
			return -EFAULT;

		hrs = alm_tm.tm_hour;
		min = alm_tm.tm_min;
		sec = alm_tm.tm_sec;

		spin_lock_irq(&rtc_lock);
		if (hpet_set_alarm_time(hrs, min, sec)) {
			/*
			 * Fallthru and set alarm time in CMOS too,
			 * so that we will get proper value in RTC_ALM_READ
			 */
		}
		if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) ||
		    RTC_ALWAYS_BCD)
		{
			if (sec < 60) BIN_TO_BCD(sec);
			else sec = 0xff;

			if (min < 60) BIN_TO_BCD(min);
			else min = 0xff;

			if (hrs < 24) BIN_TO_BCD(hrs);
			else hrs = 0xff;
		}
		CMOS_WRITE(hrs, RTC_HOURS_ALARM);
		CMOS_WRITE(min, RTC_MINUTES_ALARM);
		CMOS_WRITE(sec, RTC_SECONDS_ALARM);
		spin_unlock_irq(&rtc_lock);

		return 0;
	}
	case RTC_RD_TIME:	/* Read the time/date from RTC	*/
	{
		memset(&wtime, 0, sizeof(struct rtc_time));
		rtc_get_rtc_time(&wtime);
		break;
	}
	case RTC_SET_TIME:	/* Set the RTC */
	{
		struct rtc_time rtc_tm;
		unsigned char mon, day, hrs, min, sec, leap_yr;
		unsigned char save_control, save_freq_select;
		unsigned int yrs;
#ifdef CONFIG_MACH_DECSTATION
		unsigned int real_yrs;
#endif

		if (!capable(CAP_SYS_TIME))
			return -EACCES;

		if (copy_from_user(&rtc_tm, (struct rtc_time __user *)arg,
				   sizeof(struct rtc_time)))
			return -EFAULT;

		yrs = rtc_tm.tm_year + 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;

		if (yrs < 1970)
			return -EINVAL;

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

		if ((mon > 12) || (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 -= epoch) > 255)    /* They are unsigned */
			return -EINVAL;

		spin_lock_irq(&rtc_lock);
#ifdef CONFIG_MACH_DECSTATION
		real_yrs = yrs;
		yrs = 72;

		/*
		 * We want to keep the year set to 73 until March
		 * for non-leap years, so that Feb, 29th is handled
		 * correctly.
		 */
		if (!leap_yr && mon < 3) {
			real_yrs--;
			yrs = 73;
		}
#endif
		/* These limits and adjustments are independent of
		 * whether the chip is in binary mode or not.
		 */
		if (yrs > 169) {
			spin_unlock_irq(&rtc_lock);
			return -EINVAL;
		}
		if (yrs >= 100)
			yrs -= 100;

		if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY)
		    || RTC_ALWAYS_BCD) {
			BIN_TO_BCD(sec);
			BIN_TO_BCD(min);
			BIN_TO_BCD(hrs);
			BIN_TO_BCD(day);
			BIN_TO_BCD(mon);
			BIN_TO_BCD(yrs);
		}

		save_control = CMOS_READ(RTC_CONTROL);
		CMOS_WRITE((save_control|RTC_SET), RTC_CONTROL);
		save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
		CMOS_WRITE((save_freq_select|RTC_DIV_RESET2), RTC_FREQ_SELECT);

#ifdef CONFIG_MACH_DECSTATION
		CMOS_WRITE(real_yrs, RTC_DEC_YEAR);
#endif
		CMOS_WRITE(yrs, RTC_YEAR);
		CMOS_WRITE(mon, RTC_MONTH);
		CMOS_WRITE(day, RTC_DAY_OF_MONTH);
		CMOS_WRITE(hrs, RTC_HOURS);
		CMOS_WRITE(min, RTC_MINUTES);
		CMOS_WRITE(sec, RTC_SECONDS);

		CMOS_WRITE(save_control, RTC_CONTROL);
		CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);

		spin_unlock_irq(&rtc_lock);
		return 0;
	}
#ifdef RTC_IRQ
	case RTC_IRQP_READ:	/* Read the periodic IRQ rate.	*/
	{
		return put_user(rtc_freq, (unsigned long __user *)arg);
	}
	case RTC_IRQP_SET:	/* Set periodic IRQ rate.	*/
	{
		int tmp = 0;
		unsigned char val;
		unsigned long flags; /* can be called from isr via rtc_control() */

		/* 
		 * The max we can do is 8192Hz.
		 */
		if ((arg < 2) || (arg > 8192))
			return -EINVAL;
		/*
		 * We don't really want Joe User generating more
		 * than 64Hz of interrupts on a multi-user machine.
		 */
		if (!kernel && (arg > rtc_max_user_freq) && (!capable(CAP_SYS_RESOURCE)))
			return -EACCES;

		while (arg > (1<<tmp))
			tmp++;

		/*
		 * Check that the input was really a power of 2.
		 */
		if (arg != (1<<tmp))
			return -EINVAL;

		spin_lock_irqsave(&rtc_lock, flags);
		if (hpet_set_periodic_freq(arg)) {
			spin_unlock_irqrestore(&rtc_lock, flags);
			return 0;
		}
		rtc_freq = arg;

		val = CMOS_READ(RTC_FREQ_SELECT) & 0xf0;
		val |= (16 - tmp);
		CMOS_WRITE(val, RTC_FREQ_SELECT);
		spin_unlock_irqrestore(&rtc_lock, flags);
		return 0;
	}
#endif
	case RTC_EPOCH_READ:	/* Read the epoch.	*/
	{
		return put_user (epoch, (unsigned long __user *)arg);
	}
	case RTC_EPOCH_SET:	/* Set the epoch.	*/
	{
		/* 
		 * There were no RTC clocks before 1900.
		 */
		if (arg < 1900)
			return -EINVAL;

		if (!capable(CAP_SYS_TIME))
			return -EACCES;

		epoch = arg;
		return 0;
	}
	default:
		return -ENOTTY;
	}
	return copy_to_user((void __user *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
}

static int rtc_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
		     unsigned long arg)
{
	return rtc_do_ioctl(cmd, arg, 0);
}

/*
 *	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.
 */

/* We use rtc_lock to protect against concurrent opens. So the BKL is not
 * needed here. Or anywhere else in this driver. */
static int rtc_open(struct inode *inode, struct file *file)
{
	spin_lock_irq (&rtc_lock);

	if(rtc_status & RTC_IS_OPEN)
		goto out_busy;

	rtc_status |= RTC_IS_OPEN;

	rtc_irq_data = 0;
	spin_unlock_irq (&rtc_lock);
	return 0;

out_busy:
	spin_unlock_irq (&rtc_lock);
	return -EBUSY;
}

static int rtc_fasync (int fd, struct file *filp, int on)

{
	return fasync_helper (fd, filp, on, &rtc_async_queue);
}

static int rtc_release(struct inode *inode, struct file *file)
{
#ifdef RTC_IRQ
	unsigned char tmp;

	if (rtc_has_irq == 0)
		goto no_irq;

	/*
	 * Turn off all interrupts once the device is no longer
	 * in use, and clear the data.
	 */

	spin_lock_irq(&rtc_lock);
	if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
		tmp = CMOS_READ(RTC_CONTROL);
		tmp &=  ~RTC_PIE;
		tmp &=  ~RTC_AIE;
		tmp &=  ~RTC_UIE;
		CMOS_WRITE(tmp, RTC_CONTROL);
		CMOS_READ(RTC_INTR_FLAGS);
	}
	if (rtc_status & RTC_TIMER_ON) {
		rtc_status &= ~RTC_TIMER_ON;
		del_timer(&rtc_irq_timer);
	}
	spin_unlock_irq(&rtc_lock);

	if (file->f_flags & FASYNC) {
		rtc_fasync (-1, file, 0);
	}
no_irq:
#endif

	spin_lock_irq (&rtc_lock);
	rtc_irq_data = 0;
	rtc_status &= ~RTC_IS_OPEN;
	spin_unlock_irq (&rtc_lock);
	return 0;
}

#ifdef RTC_IRQ
/* Called without the kernel lock - fine */
static unsigned int rtc_poll(struct file *file, poll_table *wait)
{
	unsigned long l;

	if (rtc_has_irq == 0)
		return 0;

	poll_wait(file, &rtc_wait, wait);

	spin_lock_irq (&rtc_lock);
	l = rtc_irq_data;
	spin_unlock_irq (&rtc_lock);

	if (l != 0)
		return POLLIN | POLLRDNORM;
	return 0;
}
#endif

/*
 * exported stuffs
 */

EXPORT_SYMBOL(rtc_register);
EXPORT_SYMBOL(rtc_unregister);
EXPORT_SYMBOL(rtc_control);

int rtc_register(rtc_task_t *task)
{
#ifndef RTC_IRQ
	return -EIO;
#else
	if (task == NULL || task->func == NULL)
		return -EINVAL;
	spin_lock_irq(&rtc_lock);
	if (rtc_status & RTC_IS_OPEN) {
		spin_unlock_irq(&rtc_lock);
		return -EBUSY;
	}
	spin_lock(&rtc_task_lock);
	if (rtc_callback) {
		spin_unlock(&rtc_task_lock);
		spin_unlock_irq(&rtc_lock);
		return -EBUSY;
	}
	rtc_status |= RTC_IS_OPEN;
	rtc_callback = task;
	spin_unlock(&rtc_task_lock);
	spin_unlock_irq(&rtc_lock);
	return 0;
#endif
}

int rtc_unregister(rtc_task_t *task)
{
#ifndef RTC_IRQ
	return -EIO;
#else
	unsigned char tmp;

	spin_lock_irq(&rtc_lock);
	spin_lock(&rtc_task_lock);
	if (rtc_callback != task) {
		spin_unlock(&rtc_task_lock);
		spin_unlock_irq(&rtc_lock);
		return -ENXIO;
	}
	rtc_callback = NULL;
	
	/* disable controls */
	if (!hpet_mask_rtc_irq_bit(RTC_PIE | RTC_AIE | RTC_UIE)) {
		tmp = CMOS_READ(RTC_CONTROL);
		tmp &= ~RTC_PIE;
		tmp &= ~RTC_AIE;
		tmp &= ~RTC_UIE;
		CMOS_WRITE(tmp, RTC_CONTROL);
		CMOS_READ(RTC_INTR_FLAGS);
	}
	if (rtc_status & RTC_TIMER_ON) {
		rtc_status &= ~RTC_TIMER_ON;
		del_timer(&rtc_irq_timer);
	}
	rtc_status &= ~RTC_IS_OPEN;
	spin_unlock(&rtc_task_lock);
	spin_unlock_irq(&rtc_lock);
	return 0;
#endif
}

int rtc_control(rtc_task_t *task, unsigned int cmd, unsigned long arg)
{
#ifndef RTC_IRQ
	return -EIO;
#else
	unsigned long flags;
	if (cmd != RTC_PIE_ON && cmd != RTC_PIE_OFF && cmd != RTC_IRQP_SET)
		return -EINVAL;
	spin_lock_irqsave(&rtc_task_lock, flags);
	if (rtc_callback != task) {
		spin_unlock_irqrestore(&rtc_task_lock, flags);
		return -ENXIO;
	}
	spin_unlock_irqrestore(&rtc_task_lock, flags);
	return rtc_do_ioctl(cmd, arg, 1);
#endif
}


/*
 *	The various file operations we support.
 */

static const struct file_operations rtc_fops = {
	.owner		= THIS_MODULE,
	.llseek		= no_llseek,
	.read		= rtc_read,
#ifdef RTC_IRQ
	.poll		= rtc_poll,
#endif
	.ioctl		= rtc_ioctl,
	.open		= rtc_open,
	.release	= rtc_release,
	.fasync		= rtc_fasync,
};

static struct miscdevice rtc_dev = {
	.minor		= RTC_MINOR,
	.name		= "rtc",
	.fops		= &rtc_fops,
};

#ifdef CONFIG_PROC_FS
static const struct file_operations rtc_proc_fops = {
	.owner = THIS_MODULE,
	.open = rtc_proc_open,
	.read  = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
};
#endif

static resource_size_t rtc_size;

static struct resource * __init rtc_request_region(resource_size_t size)
{
	struct resource *r;

	if (RTC_IOMAPPED)
		r = request_region(RTC_PORT(0), size, "rtc");
	else
		r = request_mem_region(RTC_PORT(0), size, "rtc");

	if (r)
		rtc_size = size;