[deliverable/linux.git] / drivers / char / ds1286.c

/*
 * DS1286 Real Time Clock interface for Linux
 *
 * Copyright (C) 1998, 1999, 2000 Ralf Baechle
 *
 * Based on code written by Paul Gortmaker.
 *
 * This driver allows use of the real time clock (built into nearly all
 * computers) from user space. It exports the /dev/rtc interface supporting
 * various ioctl() and also the /proc/rtc pseudo-file for status
 * information.
 *
 * The ioctls can be used to set the interrupt behaviour and generation rate
 * from the RTC via IRQ 8. Then the /dev/rtc interface can be used to make
 * use of these timer interrupts, be they interval or alarm based.
 *
 * The /dev/rtc interface will block on reads until an interrupt has been
 * received. If a RTC interrupt has already happened, it will output an
 * unsigned long and then block. The output value contains the interrupt
 * status in the low byte and the number of interrupts since the last read
 * in the remaining high bytes. The /dev/rtc interface can also be used with
 * the select(2) call.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation; either version 2 of the License, or (at your
 * option) any later version.
 */
#include <linux/ds1286.h>
#include <linux/smp_lock.h>
#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>
#include <linux/spinlock.h>
#include <linux/bcd.h>
#include <linux/proc_fs.h>
#include <linux/jiffies.h>

#include <asm/uaccess.h>
#include <asm/system.h>

#define DS1286_VERSION		"1.0"

/*
 *	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.
 */

static DECLARE_WAIT_QUEUE_HEAD(ds1286_wait);

static ssize_t ds1286_read(struct file *file, char *buf,
			size_t count, loff_t *ppos);

static int ds1286_ioctl(struct inode *inode, struct file *file,
                        unsigned int cmd, unsigned long arg);

static unsigned int ds1286_poll(struct file *file, poll_table *wait);

static void ds1286_get_alm_time (struct rtc_time *alm_tm);
static void ds1286_get_time(struct rtc_time *rtc_tm);
static int ds1286_set_time(struct rtc_time *rtc_tm);

static inline unsigned char ds1286_is_updating(void);

static DEFINE_SPINLOCK(ds1286_lock);

static int ds1286_read_proc(char *page, char **start, off_t off,
                            int count, int *eof, void *data);

/*
 *	Bits in rtc_status. (7 bits of room for future expansion)
 */

#define RTC_IS_OPEN		0x01	/* means /dev/rtc is in use	*/
#define RTC_TIMER_ON		0x02	/* missed irq timer active	*/

static unsigned char ds1286_status;	/* bitmapped status byte.	*/

static unsigned char days_in_mo[] = {
	0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
};

/*
 *	Now all the various file operations that we export.
 */

static ssize_t ds1286_read(struct file *file, char *buf,
                           size_t count, loff_t *ppos)
{
	return -EIO;
}

static int ds1286_ioctl(struct inode *inode, struct file *file,
                        unsigned int cmd, unsigned long arg)
{
	struct rtc_time wtime;

	switch (cmd) {
	case RTC_AIE_OFF:	/* Mask alarm int. enab. bit	*/
	{
		unsigned long flags;
		unsigned char val;

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

		spin_lock_irqsave(&ds1286_lock, flags);
		val = rtc_read(RTC_CMD);
		val |=  RTC_TDM;
		rtc_write(val, RTC_CMD);
		spin_unlock_irqrestore(&ds1286_lock, flags);

		return 0;
	}
	case RTC_AIE_ON:	/* Allow alarm interrupts.	*/
	{
		unsigned long flags;
		unsigned char val;

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

		spin_lock_irqsave(&ds1286_lock, flags);
		val = rtc_read(RTC_CMD);
		val &=  ~RTC_TDM;
		rtc_write(val, RTC_CMD);
		spin_unlock_irqrestore(&ds1286_lock, flags);

		return 0;
	}
	case RTC_WIE_OFF:	/* Mask watchdog int. enab. bit	*/
	{
		unsigned long flags;
		unsigned char val;

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

		spin_lock_irqsave(&ds1286_lock, flags);
		val = rtc_read(RTC_CMD);
		val |= RTC_WAM;
		rtc_write(val, RTC_CMD);
		spin_unlock_irqrestore(&ds1286_lock, flags);

		return 0;
	}
	case RTC_WIE_ON:	/* Allow watchdog interrupts.	*/
	{
		unsigned long flags;
		unsigned char val;

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

		spin_lock_irqsave(&ds1286_lock, flags);
		val = rtc_read(RTC_CMD);
		val &= ~RTC_WAM;
		rtc_write(val, RTC_CMD);
		spin_unlock_irqrestore(&ds1286_lock, flags);

		return 0;
	}
	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(wtime));
		ds1286_get_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 (!capable(CAP_SYS_TIME))
			return -EACCES;

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

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

		if (hrs >= 24)
			hrs = 0xff;

		if (min >= 60)
			min = 0xff;

		if (sec != 0)
			return -EINVAL;

		min = BIN2BCD(min);
		min = BIN2BCD(hrs);

		spin_lock(&ds1286_lock);
		rtc_write(hrs, RTC_HOURS_ALARM);
		rtc_write(min, RTC_MINUTES_ALARM);
		spin_unlock(&ds1286_lock);

		return 0;
	}
	case RTC_RD_TIME:	/* Read the time/date from RTC	*/
	{
		memset(&wtime, 0, sizeof(wtime));
		ds1286_get_time(&wtime);
		break;
	}
	case RTC_SET_TIME:	/* Set the RTC */
	{
		struct rtc_time rtc_tm;

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

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

		return ds1286_set_time(&rtc_tm);
	}
	default:
		return -EINVAL;
	}
	return copy_to_user((void *)arg, &wtime, sizeof wtime) ? -EFAULT : 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.
 */

static int ds1286_open(struct inode *inode, struct file *file)
{
	lock_kernel();
	spin_lock_irq(&ds1286_lock);

	if (ds1286_status & RTC_IS_OPEN)
		goto out_busy;

	ds1286_status |= RTC_IS_OPEN;

	spin_unlock_irq(&ds1286_lock);
	unlock_kernel();
	return 0;

out_busy:
	spin_lock_irq(&ds1286_lock);
	unlock_kernel();
	return -EBUSY;
}

static int ds1286_release(struct inode *inode, struct file *file)
{
	ds1286_status &= ~RTC_IS_OPEN;

	return 0;
}

static unsigned int ds1286_poll(struct file *file, poll_table *wait)
{
	poll_wait(file, &ds1286_wait, wait);

	return 0;
}

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

static const struct file_operations ds1286_fops = {
	.llseek		= no_llseek,
	.read		= ds1286_read,
	.poll		= ds1286_poll,
	.ioctl		= ds1286_ioctl,
	.open		= ds1286_open,
	.release	= ds1286_release,
};

static struct miscdevice ds1286_dev=
{
	.minor	= RTC_MINOR,
	.name	= "rtc",
	.fops	= &ds1286_fops,
};

static int __init ds1286_init(void)
{
	int err;

	printk(KERN_INFO "DS1286 Real Time Clock Driver v%s\n", DS1286_VERSION);

	err = misc_register(&ds1286_dev);
	if (err)
		goto out;

	if (!create_proc_read_entry("driver/rtc", 0, 0, ds1286_read_proc, NULL)) {
		err = -ENOMEM;

		goto out_deregister;
	}

	return 0;

out_deregister:
	misc_deregister(&ds1286_dev);

out:
	return err;
}

static void __exit ds1286_exit(void)
{
	remove_proc_entry("driver/rtc", NULL);
	misc_deregister(&ds1286_dev);
}

static char *days[] = {
	"***", "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
};

/*
 *	Info exported via "/proc/rtc".
 */
static int ds1286_proc_output(char *buf)
{
	char *p, *s;
	struct rtc_time tm;
	unsigned char hundredth, month, cmd, amode;

	p = buf;

	ds1286_get_time(&tm);
	hundredth = rtc_read(RTC_HUNDREDTH_SECOND);
	BCD_TO_BIN(hundredth);

	p += sprintf(p,
	             "rtc_time\t: %02d:%02d:%02d.%02d\n"
	             "rtc_date\t: %04d-%02d-%02d\n",
		     tm.tm_hour, tm.tm_min, tm.tm_sec, hundredth,
		     tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);

	/*
	 * We implicitly assume 24hr mode here. Alarm values >= 0xc0 will
	 * match any value for that particular field. Values that are
	 * greater than a valid time, but less than 0xc0 shouldn't appear.
	 */
	ds1286_get_alm_time(&tm);
	p += sprintf(p, "alarm\t\t: %s ", days[tm.tm_wday]);
	if (tm.tm_hour <= 24)
		p += sprintf(p, "%02d:", tm.tm_hour);
	else
		p += sprintf(p, "**:");

	if (tm.tm_min <= 59)
		p += sprintf(p, "%02d\n", tm.tm_min);
	else
		p += sprintf(p, "**\n");

	month = rtc_read(RTC_MONTH);
	p += sprintf(p,
	             "oscillator\t: %s\n"
	             "square_wave\t: %s\n",
	             (month & RTC_EOSC) ? "disabled" : "enabled",
	             (month & RTC_ESQW) ? "disabled" : "enabled");

	amode = ((rtc_read(RTC_MINUTES_ALARM) & 0x80) >> 5) |
	        ((rtc_read(RTC_HOURS_ALARM) & 0x80) >> 6) |
	        ((rtc_read(RTC_DAY_ALARM) & 0x80) >> 7);
	if (amode == 7)      s = "each minute";
	else if (amode == 3) s = "minutes match";
	else if (amode == 1) s = "hours and minutes match";
	else if (amode == 0) s = "days, hours and minutes match";
	else                 s = "invalid";
	p += sprintf(p, "alarm_mode\t: %s\n", s);

	cmd = rtc_read(RTC_CMD);
	p += sprintf(p,
	             "alarm_enable\t: %s\n"
	             "wdog_alarm\t: %s\n"
	             "alarm_mask\t: %s\n"
	             "wdog_alarm_mask\t: %s\n"
	             "interrupt_mode\t: %s\n"
	             "INTB_mode\t: %s_active\n"
	             "interrupt_pins\t: %s\n",
		     (cmd & RTC_TDF) ? "yes" : "no",
		     (cmd & RTC_WAF) ? "yes" : "no",
		     (cmd & RTC_TDM) ? "disabled" : "enabled",
		     (cmd & RTC_WAM) ? "disabled" : "enabled",
		     (cmd & RTC_PU_LVL) ? "pulse" : "level",
		     (cmd & RTC_IBH_LO) ? "low" : "high",
	             (cmd & RTC_IPSW) ? "unswapped" : "swapped");

	return  p - buf;
}

static int ds1286_read_proc(char *page, char **start, off_t off,
                         int count, int *eof, void *data)
{
	int len = ds1286_proc_output (page);
	if (len <= off+count) *eof = 1;
	*start = page + off;
	len -= off;
	if (len>count)
		len = count;
	if (len<0)
		len = 0;

	return len;
}

/*
 * Returns true if a clock update is in progress
 */
static inline unsigned char ds1286_is_updating(void)
{
	return rtc_read(RTC_CMD) & RTC_TE;
}


static void ds1286_get_time(struct rtc_time *rtc_tm)
{
	unsigned char save_control;
	unsigned long flags;
	unsigned long uip_watchdog = jiffies;

	/*
	 * read RTC once any update in progress is done. The update
	 * can take just over 2ms. We wait 10 to 20ms. There is no need to
	 * to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
	 * If you need to know *exactly* when a second has started, enable
	 * periodic update complete interrupts, (via ioctl) and then
	 * immediately read /dev/rtc which will block until you get the IRQ.
	 * Once the read clears, read the RTC time (again via ioctl). Easy.
	 */

	if (ds1286_is_updating() != 0)
		while (time_before(jiffies, uip_watchdog + 2*HZ/100))
			barrier();

	/*
	 * Only the values that we read from the RTC are set. We leave
	 * tm_wday, tm_yday and tm_isdst untouched. Even though the
	 * RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
	 * by the RTC when initially set to a non-zero value.
	 */
	spin_lock_irqsave(&ds1286_lock, flags);
	save_control = rtc_read(RTC_CMD);
	rtc_write((save_control|RTC_TE), RTC_CMD);

	rtc_tm->tm_sec = rtc_read(RTC_SECONDS);
	rtc_tm->tm_min = rtc_read(RTC_MINUTES);
	rtc_tm->tm_hour = rtc_read(RTC_HOURS) & 0x3f;
	rtc_tm->tm_mday = rtc_read(RTC_DATE);
	rtc_tm->tm_mon = rtc_read(RTC_MONTH) & 0x1f;
	rtc_tm->tm_year = rtc_read(RTC_YEAR);

	rtc_write(save_control, RTC_CMD);
	spin_unlock_irqrestore(&ds1286_lock, flags);

	BCD_TO_BIN(rtc_tm->tm_sec);
	BCD_TO_BIN(rtc_tm->tm_min);
	BCD_TO_BIN(rtc_tm->tm_hour);
	BCD_TO_BIN(rtc_tm->tm_mday);
	BCD_TO_BIN(rtc_tm->tm_mon);
	BCD_TO_BIN(rtc_tm->tm_year);

	/*
	 * Account for differences between how the RTC uses the values
	 * and how they are defined in a struct rtc_time;
	 */
	if (rtc_tm->tm_year < 45)
		rtc_tm->tm_year += 30;
	if ((rtc_tm->tm_year += 40) < 70)
		rtc_tm->tm_year += 100;

	rtc_tm->tm_mon--;
}

static int ds1286_set_time(struct rtc_time *rtc_tm)
{
	unsigned char mon, day, hrs, min, sec, leap_yr;
	unsigned char save_control;
	unsigned int yrs;
	unsigned long flags;


	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 -= 1940) > 255)    /* They are unsigned */
		return -EINVAL;

	if (yrs >= 100)
		yrs -= 100;

	BIN_TO_BCD(sec);
	BIN_TO_BCD(min);
	BIN_TO_BCD(hrs);
	BIN_TO_BCD(day);
	BIN_TO_BCD(mon);
	BIN_TO_BCD(yrs);

	spin_lock_irqsave(&ds1286_lock, flags);
	save_control = rtc_read(RTC_CMD);
	rtc_write((save_control|RTC_TE), RTC_CMD);

	rtc_write(yrs, RTC_YEAR);
	rtc_write(mon, RTC_MONTH);
	rtc_write(day, RTC_DATE);
	rtc_write(hrs, RTC_HOURS);
	rtc_write(min, RTC_MINUTES);
	rtc_write(sec, RTC_SECONDS);
	rtc_write(0, RTC_HUNDREDTH_SECOND);

	rtc_write(save_control, RTC_CMD);
	spin_unlock_irqrestore(&ds1286_lock, flags);

	return 0;
}

static void ds1286_get_alm_time(struct rtc_time *alm_tm)
{
	unsigned char cmd;
	unsigned long flags;

	/*
	 * Only the values that we read from the RTC are set. That
	 * means only tm_wday, tm_hour, tm_min.
	 */
	spin_lock_irqsave(&ds1286_lock, flags);
	alm_tm->tm_min = rtc_read(RTC_MINUTES_ALARM) & 0x7f;
	alm_tm->tm_hour = rtc_read(RTC_HOURS_ALARM)  & 0x1f;
	alm_tm->tm_wday = rtc_read(RTC_DAY_ALARM)    & 0x07;
	cmd = rtc_read(RTC_CMD);
	spin_unlock_irqrestore(&ds1286_lock, flags);

	BCD_TO_BIN(alm_tm->tm_min);
	BCD_TO_BIN(alm_tm->tm_hour);
	alm_tm->tm_sec = 0;
}

module_init(ds1286_init);
module_exit(ds1286_exit);

MODULE_AUTHOR("Ralf Baechle");
MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(RTC_MINOR);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* DS1286 Real Time Clock interface for Linux
	3	*
	4	* Copyright (C) 1998, 1999, 2000 Ralf Baechle
	5	*
	6	* Based on code written by Paul Gortmaker.
	7	*
	8	* This driver allows use of the real time clock (built into nearly all
	9	* computers) from user space. It exports the /dev/rtc interface supporting
	10	* various ioctl() and also the /proc/rtc pseudo-file for status
	11	* information.
	12	*
	13	* The ioctls can be used to set the interrupt behaviour and generation rate
	14	* from the RTC via IRQ 8. Then the /dev/rtc interface can be used to make
	15	* use of these timer interrupts, be they interval or alarm based.
	16	*
	17	* The /dev/rtc interface will block on reads until an interrupt has been
	18	* received. If a RTC interrupt has already happened, it will output an
	19	* unsigned long and then block. The output value contains the interrupt
	20	* status in the low byte and the number of interrupts since the last read
	21	* in the remaining high bytes. The /dev/rtc interface can also be used with
	22	* the select(2) call.
	23	*
	24	* This program is free software; you can redistribute it and/or modify it
	25	* under the terms of the GNU General Public License as published by the
	26	* Free Software Foundation; either version 2 of the License, or (at your
	27	* option) any later version.
	28	*/
	29	#include <linux/ds1286.h>
7ccef463	30	#include <linux/smp_lock.h>
1da177e4 LT	31	#include <linux/types.h>
	32	#include <linux/errno.h>
	33	#include <linux/miscdevice.h>
	34	#include <linux/slab.h>
	35	#include <linux/ioport.h>
	36	#include <linux/fcntl.h>
	37	#include <linux/init.h>
	38	#include <linux/poll.h>
	39	#include <linux/rtc.h>
	40	#include <linux/spinlock.h>
	41	#include <linux/bcd.h>
	42	#include <linux/proc_fs.h>
ac0e4b7d	43	#include <linux/jiffies.h>
1da177e4 LT	44
	45	#include <asm/uaccess.h>
	46	#include <asm/system.h>
	47
	48	#define DS1286_VERSION "1.0"
	49
	50	/*
	51	* We sponge a minor off of the misc major. No need slurping
	52	* up another valuable major dev number for this. If you add
	53	* an ioctl, make sure you don't conflict with SPARC's RTC
	54	* ioctls.
	55	*/
	56
	57	static DECLARE_WAIT_QUEUE_HEAD(ds1286_wait);
	58
	59	static ssize_t ds1286_read(struct file file, char buf,
	60	size_t count, loff_t *ppos);
	61
	62	static int ds1286_ioctl(struct inode inode, struct file file,
	63	unsigned int cmd, unsigned long arg);
	64
	65	static unsigned int ds1286_poll(struct file file, poll_table wait);
	66
	67	static void ds1286_get_alm_time (struct rtc_time *alm_tm);
	68	static void ds1286_get_time(struct rtc_time *rtc_tm);
	69	static int ds1286_set_time(struct rtc_time *rtc_tm);
	70
	71	static inline unsigned char ds1286_is_updating(void);
	72
	73	static DEFINE_SPINLOCK(ds1286_lock);
	74
	75	static int ds1286_read_proc(char page, char *start, off_t off,
	76	int count, int eof, void data);
	77
	78	/*
	79	* Bits in rtc_status. (7 bits of room for future expansion)
	80	*/
	81
	82	#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
	83	#define RTC_TIMER_ON 0x02 /* missed irq timer active */
	84
	85	static unsigned char ds1286_status; /* bitmapped status byte. */
	86
	87	static unsigned char days_in_mo[] = {
	88	0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
	89	};
	90
	91	/*
	92	* Now all the various file operations that we export.
	93	*/
	94
	95	static ssize_t ds1286_read(struct file file, char buf,
	96	size_t count, loff_t *ppos)
	97	{
	98	return -EIO;
	99	}
	100
	101	static int ds1286_ioctl(struct inode inode, struct file file,
	102	unsigned int cmd, unsigned long arg)
	103	{
	104	struct rtc_time wtime;
	105
	106	switch (cmd) {
	107	case RTC_AIE_OFF: /* Mask alarm int. enab. bit */
108	{
c53421b1	109	unsigned long flags;
1da177e4 LT	110	unsigned char val;
	111
	112	if (!capable(CAP_SYS_TIME))
	113	return -EACCES;
	114
	115	spin_lock_irqsave(&ds1286_lock, flags);
	116	val = rtc_read(RTC_CMD);
	117	val \|= RTC_TDM;
	118	rtc_write(val, RTC_CMD);
	119	spin_unlock_irqrestore(&ds1286_lock, flags);
	120
	121	return 0;
	122	}
	123	case RTC_AIE_ON: /* Allow alarm interrupts. */
	124	{
c53421b1	125	unsigned long flags;
1da177e4 LT	126	unsigned char val;
	127
	128	if (!capable(CAP_SYS_TIME))
	129	return -EACCES;
	130
	131	spin_lock_irqsave(&ds1286_lock, flags);
	132	val = rtc_read(RTC_CMD);
	133	val &= ~RTC_TDM;
	134	rtc_write(val, RTC_CMD);
	135	spin_unlock_irqrestore(&ds1286_lock, flags);
	136
	137	return 0;
	138	}
	139	case RTC_WIE_OFF: /* Mask watchdog int. enab. bit */
	140	{
c53421b1	141	unsigned long flags;
1da177e4 LT	142	unsigned char val;
	143
	144	if (!capable(CAP_SYS_TIME))
	145	return -EACCES;
	146
	147	spin_lock_irqsave(&ds1286_lock, flags);
	148	val = rtc_read(RTC_CMD);
	149	val \|= RTC_WAM;
	150	rtc_write(val, RTC_CMD);
	151	spin_unlock_irqrestore(&ds1286_lock, flags);
	152
	153	return 0;
	154	}
	155	case RTC_WIE_ON: /* Allow watchdog interrupts. */
	156	{
c53421b1	157	unsigned long flags;
1da177e4 LT	158	unsigned char val;
	159
	160	if (!capable(CAP_SYS_TIME))
	161	return -EACCES;
	162
	163	spin_lock_irqsave(&ds1286_lock, flags);
	164	val = rtc_read(RTC_CMD);
	165	val &= ~RTC_WAM;
	166	rtc_write(val, RTC_CMD);
	167	spin_unlock_irqrestore(&ds1286_lock, flags);
	168
	169	return 0;
	170	}
	171	case RTC_ALM_READ: /* Read the present alarm time */
	172	{
	173	/*
	174	* This returns a struct rtc_time. Reading >= 0xc0
	175	* means "don't care" or "match all". Only the tm_hour,
	176	* tm_min, and tm_sec values are filled in.
	177	*/
	178
	179	memset(&wtime, 0, sizeof(wtime));
	180	ds1286_get_alm_time(&wtime);
	181	break;
	182	}
	183	case RTC_ALM_SET: /* Store a time into the alarm */
	184	{
	185	/*
	186	* This expects a struct rtc_time. Writing 0xff means
	187	* "don't care" or "match all". Only the tm_hour,
	188	* tm_min and tm_sec are used.
	189	*/
	190	unsigned char hrs, min, sec;
	191	struct rtc_time alm_tm;
	192
	193	if (!capable(CAP_SYS_TIME))
	194	return -EACCES;
	195
	196	if (copy_from_user(&alm_tm, (struct rtc_time*)arg,
	197	sizeof(struct rtc_time)))
	198	return -EFAULT;
	199
	200	hrs = alm_tm.tm_hour;
	201	min = alm_tm.tm_min;
b35692eb	202	sec = alm_tm.tm_sec;
1da177e4 LT	203
	204	if (hrs >= 24)
	205	hrs = 0xff;
	206
	207	if (min >= 60)
	208	min = 0xff;
	209
b35692eb RB	210	if (sec != 0)
	211	return -EINVAL;
	212
	213	min = BIN2BCD(min);
	214	min = BIN2BCD(hrs);
1da177e4 LT	215
	216	spin_lock(&ds1286_lock);
	217	rtc_write(hrs, RTC_HOURS_ALARM);
	218	rtc_write(min, RTC_MINUTES_ALARM);
	219	spin_unlock(&ds1286_lock);
	220
	221	return 0;
	222	}
	223	case RTC_RD_TIME: /* Read the time/date from RTC */
	224	{
	225	memset(&wtime, 0, sizeof(wtime));
	226	ds1286_get_time(&wtime);
	227	break;
	228	}
	229	case RTC_SET_TIME: /* Set the RTC */
	230	{
	231	struct rtc_time rtc_tm;
	232
	233	if (!capable(CAP_SYS_TIME))
	234	return -EACCES;
	235
	236	if (copy_from_user(&rtc_tm, (struct rtc_time*)arg,
	237	sizeof(struct rtc_time)))
	238	return -EFAULT;
	239
	240	return ds1286_set_time(&rtc_tm);
	241	}
	242	default:
	243	return -EINVAL;
	244	}
	245	return copy_to_user((void *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
	246	}
	247
	248	/*
	249	* We enforce only one user at a time here with the open/close.
	250	* Also clear the previous interrupt data on an open, and clean
	251	* up things on a close.
	252	*/
	253
	254	static int ds1286_open(struct inode inode, struct file file)
	255	{
7ccef463	256	lock_kernel();
1da177e4 LT	257	spin_lock_irq(&ds1286_lock);
	258
	259	if (ds1286_status & RTC_IS_OPEN)
	260	goto out_busy;
	261
	262	ds1286_status \|= RTC_IS_OPEN;
	263
	264	spin_unlock_irq(&ds1286_lock);
7ccef463	265	unlock_kernel();
1da177e4 LT	266	return 0;
	267
	268	out_busy:
	269	spin_lock_irq(&ds1286_lock);
7ccef463	270	unlock_kernel();
1da177e4 LT	271	return -EBUSY;
	272	}
	273
	274	static int ds1286_release(struct inode inode, struct file file)
	275	{
	276	ds1286_status &= ~RTC_IS_OPEN;
	277
	278	return 0;
	279	}
	280
	281	static unsigned int ds1286_poll(struct file file, poll_table wait)
	282	{
	283	poll_wait(file, &ds1286_wait, wait);
	284
	285	return 0;
	286	}
	287
	288	/*
	289	* The various file operations we support.
	290	*/
	291
62322d25	292	static const struct file_operations ds1286_fops = {
1da177e4 LT	293	.llseek = no_llseek,
	294	.read = ds1286_read,
	295	.poll = ds1286_poll,
	296	.ioctl = ds1286_ioctl,
	297	.open = ds1286_open,
	298	.release = ds1286_release,
	299	};
	300
	301	static struct miscdevice ds1286_dev=
	302	{
	303	.minor = RTC_MINOR,
	304	.name = "rtc",
	305	.fops = &ds1286_fops,
	306	};
	307
	308	static int __init ds1286_init(void)
	309	{
	310	int err;
	311
	312	printk(KERN_INFO "DS1286 Real Time Clock Driver v%s\n", DS1286_VERSION);
	313
	314	err = misc_register(&ds1286_dev);
	315	if (err)
	316	goto out;
	317
	318	if (!create_proc_read_entry("driver/rtc", 0, 0, ds1286_read_proc, NULL)) {
	319	err = -ENOMEM;
	320
	321	goto out_deregister;
	322	}
	323
	324	return 0;
	325
	326	out_deregister:
	327	misc_deregister(&ds1286_dev);
	328
	329	out:
	330	return err;
	331	}
	332
	333	static void __exit ds1286_exit(void)
	334	{
	335	remove_proc_entry("driver/rtc", NULL);
	336	misc_deregister(&ds1286_dev);
	337	}
	338
	339	static char *days[] = {
	340	"***", "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
	341	};
	342
	343	/*
	344	* Info exported via "/proc/rtc".
	345	*/
	346	static int ds1286_proc_output(char *buf)
	347	{
	348	char p, s;
	349	struct rtc_time tm;
	350	unsigned char hundredth, month, cmd, amode;
	351
	352	p = buf;
	353
	354	ds1286_get_time(&tm);
	355	hundredth = rtc_read(RTC_HUNDREDTH_SECOND);
	356	BCD_TO_BIN(hundredth);
357
358	p += sprintf(p,
359	"rtc_time\t: %02d:%02d:%02d.%02d\n"
360	"rtc_date\t: %04d-%02d-%02d\n",
361	tm.tm_hour, tm.tm_min, tm.tm_sec, hundredth,
362	tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
363
364	/*
365	* We implicitly assume 24hr mode here. Alarm values >= 0xc0 will
366	* match any value for that particular field. Values that are
367	* greater than a valid time, but less than 0xc0 shouldn't appear.
368	*/
369	ds1286_get_alm_time(&tm);
370	p += sprintf(p, "alarm\t\t: %s ", days[tm.tm_wday]);
371	if (tm.tm_hour <= 24)
372	p += sprintf(p, "%02d:", tm.tm_hour);
373	else
374	p += sprintf(p, "**:");
375
376	if (tm.tm_min <= 59)
377	p += sprintf(p, "%02d\n", tm.tm_min);
378	else
379	p += sprintf(p, "**\n");
380
381	month = rtc_read(RTC_MONTH);
382	p += sprintf(p,
383	"oscillator\t: %s\n"
384	"square_wave\t: %s\n",
385	(month & RTC_EOSC) ? "disabled" : "enabled",
386	(month & RTC_ESQW) ? "disabled" : "enabled");
387
388	amode = ((rtc_read(RTC_MINUTES_ALARM) & 0x80) >> 5) \|
389	((rtc_read(RTC_HOURS_ALARM) & 0x80) >> 6) \|
390	((rtc_read(RTC_DAY_ALARM) & 0x80) >> 7);
391	if (amode == 7) s = "each minute";
392	else if (amode == 3) s = "minutes match";
393	else if (amode == 1) s = "hours and minutes match";
394	else if (amode == 0) s = "days, hours and minutes match";
395	else s = "invalid";
396	p += sprintf(p, "alarm_mode\t: %s\n", s);
397
398	cmd = rtc_read(RTC_CMD);
399	p += sprintf(p,
400	"alarm_enable\t: %s\n"
401	"wdog_alarm\t: %s\n"
402	"alarm_mask\t: %s\n"
403	"wdog_alarm_mask\t: %s\n"
404	"interrupt_mode\t: %s\n"
405	"INTB_mode\t: %s_active\n"
406	"interrupt_pins\t: %s\n",
407	(cmd & RTC_TDF) ? "yes" : "no",
408	(cmd & RTC_WAF) ? "yes" : "no",
409	(cmd & RTC_TDM) ? "disabled" : "enabled",
410	(cmd & RTC_WAM) ? "disabled" : "enabled",
411	(cmd & RTC_PU_LVL) ? "pulse" : "level",
412	(cmd & RTC_IBH_LO) ? "low" : "high",
413	(cmd & RTC_IPSW) ? "unswapped" : "swapped");
414
415	return p - buf;
416	}
417
418	static int ds1286_read_proc(char page, char *start, off_t off,
419	int count, int eof, void data)
420	{
421	int len = ds1286_proc_output (page);
422	if (len <= off+count) *eof = 1;
423	*start = page + off;
424	len -= off;
425	if (len>count)
426	len = count;
427	if (len<0)
428	len = 0;
429
430	return len;
431	}
432
433	/*
434	* Returns true if a clock update is in progress
435	*/
436	static inline unsigned char ds1286_is_updating(void)
437	{
438	return rtc_read(RTC_CMD) & RTC_TE;
439	}
440
441
442	static void ds1286_get_time(struct rtc_time *rtc_tm)
443	{
444	unsigned char save_control;
c53421b1	445	unsigned long flags;
1da177e4 LT	446	unsigned long uip_watchdog = jiffies;
	447
	448	/*
	449	* read RTC once any update in progress is done. The update
	450	* can take just over 2ms. We wait 10 to 20ms. There is no need to
	451	* to poll-wait (up to 1s - eeccch) for the falling edge of RTC_UIP.
	452	* If you need to know exactly when a second has started, enable
	453	* periodic update complete interrupts, (via ioctl) and then
	454	* immediately read /dev/rtc which will block until you get the IRQ.
	455	* Once the read clears, read the RTC time (again via ioctl). Easy.
	456	*/
	457
	458	if (ds1286_is_updating() != 0)
ac0e4b7d	459	while (time_before(jiffies, uip_watchdog + 2*HZ/100))
1da177e4 LT	460	barrier();
	461
	462	/*
	463	* Only the values that we read from the RTC are set. We leave
	464	* tm_wday, tm_yday and tm_isdst untouched. Even though the
	465	* RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
	466	* by the RTC when initially set to a non-zero value.
	467	*/
	468	spin_lock_irqsave(&ds1286_lock, flags);
	469	save_control = rtc_read(RTC_CMD);
	470	rtc_write((save_control\|RTC_TE), RTC_CMD);
	471
	472	rtc_tm->tm_sec = rtc_read(RTC_SECONDS);
	473	rtc_tm->tm_min = rtc_read(RTC_MINUTES);
	474	rtc_tm->tm_hour = rtc_read(RTC_HOURS) & 0x3f;
	475	rtc_tm->tm_mday = rtc_read(RTC_DATE);
	476	rtc_tm->tm_mon = rtc_read(RTC_MONTH) & 0x1f;
	477	rtc_tm->tm_year = rtc_read(RTC_YEAR);
	478
	479	rtc_write(save_control, RTC_CMD);
	480	spin_unlock_irqrestore(&ds1286_lock, flags);
	481
	482	BCD_TO_BIN(rtc_tm->tm_sec);
	483	BCD_TO_BIN(rtc_tm->tm_min);
	484	BCD_TO_BIN(rtc_tm->tm_hour);
	485	BCD_TO_BIN(rtc_tm->tm_mday);
	486	BCD_TO_BIN(rtc_tm->tm_mon);
	487	BCD_TO_BIN(rtc_tm->tm_year);
	488
	489	/*
	490	* Account for differences between how the RTC uses the values
	491	* and how they are defined in a struct rtc_time;
	492	*/
	493	if (rtc_tm->tm_year < 45)
	494	rtc_tm->tm_year += 30;
	495	if ((rtc_tm->tm_year += 40) < 70)
	496	rtc_tm->tm_year += 100;
	497
	498	rtc_tm->tm_mon--;
	499	}
	500
	501	static int ds1286_set_time(struct rtc_time *rtc_tm)
	502	{
	503	unsigned char mon, day, hrs, min, sec, leap_yr;
	504	unsigned char save_control;
c53421b1 AD	505	unsigned int yrs;
c53421b1 AD	506	unsigned long flags;
1da177e4 LT	507
	508
	509	yrs = rtc_tm->tm_year + 1900;
	510	mon = rtc_tm->tm_mon + 1; /* tm_mon starts at zero */
	511	day = rtc_tm->tm_mday;
	512	hrs = rtc_tm->tm_hour;
	513	min = rtc_tm->tm_min;
	514	sec = rtc_tm->tm_sec;
	515
	516	if (yrs < 1970)
	517	return -EINVAL;
	518
	519	leap_yr = ((!(yrs % 4) && (yrs % 100)) \|\| !(yrs % 400));
	520
	521	if ((mon > 12) \|\| (day == 0))
	522	return -EINVAL;
	523
	524	if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
	525	return -EINVAL;
	526
	527	if ((hrs >= 24) \|\| (min >= 60) \|\| (sec >= 60))
	528	return -EINVAL;
	529
	530	if ((yrs -= 1940) > 255) /* They are unsigned */
	531	return -EINVAL;
	532
	533	if (yrs >= 100)
	534	yrs -= 100;
	535
	536	BIN_TO_BCD(sec);
	537	BIN_TO_BCD(min);
	538	BIN_TO_BCD(hrs);
	539	BIN_TO_BCD(day);
	540	BIN_TO_BCD(mon);
	541	BIN_TO_BCD(yrs);
	542
	543	spin_lock_irqsave(&ds1286_lock, flags);
	544	save_control = rtc_read(RTC_CMD);
	545	rtc_write((save_control\|RTC_TE), RTC_CMD);
	546
	547	rtc_write(yrs, RTC_YEAR);
	548	rtc_write(mon, RTC_MONTH);
	549	rtc_write(day, RTC_DATE);
	550	rtc_write(hrs, RTC_HOURS);
	551	rtc_write(min, RTC_MINUTES);
	552	rtc_write(sec, RTC_SECONDS);
	553	rtc_write(0, RTC_HUNDREDTH_SECOND);
	554
	555	rtc_write(save_control, RTC_CMD);
	556	spin_unlock_irqrestore(&ds1286_lock, flags);
	557
	558	return 0;
	559	}
	560
	561	static void ds1286_get_alm_time(struct rtc_time *alm_tm)
	562	{
	563	unsigned char cmd;
c53421b1	564	unsigned long flags;
1da177e4 LT	565
	566	/*
	567	* Only the values that we read from the RTC are set. That
	568	* means only tm_wday, tm_hour, tm_min.
	569	*/
	570	spin_lock_irqsave(&ds1286_lock, flags);
	571	alm_tm->tm_min = rtc_read(RTC_MINUTES_ALARM) & 0x7f;
	572	alm_tm->tm_hour = rtc_read(RTC_HOURS_ALARM) & 0x1f;
	573	alm_tm->tm_wday = rtc_read(RTC_DAY_ALARM) & 0x07;
	574	cmd = rtc_read(RTC_CMD);
	575	spin_unlock_irqrestore(&ds1286_lock, flags);
	576
	577	BCD_TO_BIN(alm_tm->tm_min);
	578	BCD_TO_BIN(alm_tm->tm_hour);
	579	alm_tm->tm_sec = 0;
	580	}
	581
	582	module_init(ds1286_init);
	583	module_exit(ds1286_exit);
	584
	585	MODULE_AUTHOR("Ralf Baechle");
	586	MODULE_LICENSE("GPL");
	587	MODULE_ALIAS_MISCDEV(RTC_MINOR);