[linux.git] / drivers / char / ip27-rtc.c

/*
 *	Driver for the SGS-Thomson M48T35 Timekeeper RAM chip
 *
 *	Real Time Clock interface for Linux
 *
 *	TODO: Implement periodic interrupts.
 *
 *	Copyright (C) 2000 Silicon Graphics, Inc.
 *	Written by Ulf Carlsson ([email protected])
 *
 *	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.
 *
 *	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.
 *
 */

#define RTC_VERSION		"1.09b"

#include <linux/bcd.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/smp_lock.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/ioport.h>
#include <linux/fcntl.h>
#include <linux/rtc.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/proc_fs.h>

#include <asm/m48t35.h>
#include <asm/sn/ioc3.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/sn/klconfig.h>
#include <asm/sn/sn0/ip27.h>
#include <asm/sn/sn0/hub.h>
#include <asm/sn/sn_private.h>

static long rtc_ioctl(struct file *filp, unsigned int cmd,
			unsigned long arg);

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

static void get_rtc_time(struct rtc_time *rtc_tm);

/*
 *	Bits in rtc_status. (6 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 rtc_status;	/* bitmapped status byte.	*/
static unsigned long rtc_freq;	/* Current periodic IRQ rate	*/
static struct m48t35_rtc *rtc;

/*
 *	If this driver ever becomes modularised, it will be really nice
 *	to make the epoch retain its value across module reload...
 */

static unsigned long epoch = 1970;	/* year corresponding to 0x00	*/

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

static long rtc_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{

	struct rtc_time wtime;

	switch (cmd) {
	case RTC_RD_TIME:	/* Read the time/date from 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 int yrs;

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

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

		if (yrs > 169)
			return -EINVAL;

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

		sec = BIN2BCD(sec);
		min = BIN2BCD(min);
		hrs = BIN2BCD(hrs);
		day = BIN2BCD(day);
		mon = BIN2BCD(mon);
		yrs = BIN2BCD(yrs);

		spin_lock_irq(&rtc_lock);
		rtc->control |= M48T35_RTC_SET;
		rtc->year = yrs;
		rtc->month = mon;
		rtc->date = day;
		rtc->hour = hrs;
		rtc->min = min;
		rtc->sec = sec;
		rtc->control &= ~M48T35_RTC_SET;
		spin_unlock_irq(&rtc_lock);

		return 0;
	}
	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 rtc_open(struct inode *inode, struct file *file)
{
	lock_kernel();
	spin_lock_irq(&rtc_lock);

	if (rtc_status & RTC_IS_OPEN) {
		spin_unlock_irq(&rtc_lock);
		unlock_kernel();
		return -EBUSY;
	}

	rtc_status |= RTC_IS_OPEN;
	spin_unlock_irq(&rtc_lock);
	unlock_kernel();

	return 0;
}

static int rtc_release(struct inode *inode, struct file *file)
{
	/*
	 * Turn off all interrupts once the device is no longer
	 * in use, and clear the data.
	 */

	spin_lock_irq(&rtc_lock);
	rtc_status &= ~RTC_IS_OPEN;
	spin_unlock_irq(&rtc_lock);

	return 0;
}

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

static const struct file_operations rtc_fops = {
	.owner		= THIS_MODULE,
	.unlocked_ioctl	= rtc_ioctl,
	.open		= rtc_open,
	.release	= rtc_release,
};

static struct miscdevice rtc_dev=
{
	RTC_MINOR,
	"rtc",
	&rtc_fops
};

static int __init rtc_init(void)
{
	rtc = (struct m48t35_rtc *)
	(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base + IOC3_BYTEBUS_DEV0);

	printk(KERN_INFO "Real Time Clock Driver v%s\n", RTC_VERSION);
	if (misc_register(&rtc_dev)) {
		printk(KERN_ERR "rtc: cannot register misc device.\n");
		return -ENODEV;
	}
	if (!create_proc_read_entry("driver/rtc", 0, NULL, rtc_read_proc, NULL)) {
		printk(KERN_ERR "rtc: cannot create /proc/rtc.\n");
		misc_deregister(&rtc_dev);
		return -ENOENT;
	}

	rtc_freq = 1024;

	return 0;
}

static void __exit rtc_exit (void)
{
	/* interrupts and timer disabled at this point by rtc_release */

	remove_proc_entry ("rtc", NULL);
	misc_deregister(&rtc_dev);
}

module_init(rtc_init);
module_exit(rtc_exit);

/*
 *	Info exported via "/proc/rtc".
 */

static int rtc_get_status(char *buf)
{
	char *p;
	struct rtc_time tm;

	/*
	 * Just emulate the standard /proc/rtc
	 */

	p = buf;

	get_rtc_time(&tm);

	/*
	 * There is no way to tell if the luser has the RTC set for local
	 * time or for Universal Standard Time (GMT). Probably local though.
	 */
	p += sprintf(p,
		     "rtc_time\t: %02d:%02d:%02d\n"
		     "rtc_date\t: %04d-%02d-%02d\n"
	 	     "rtc_epoch\t: %04lu\n"
		     "24hr\t\t: yes\n",
		     tm.tm_hour, tm.tm_min, tm.tm_sec,
		     tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);

	return  p - buf;
}

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

static void get_rtc_time(struct rtc_time *rtc_tm)
{
	/*
	 * Do we need to wait for the last update to finish?
	 */

	/*
	 * 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_irq(&rtc_lock);
	rtc->control |= M48T35_RTC_READ;
	rtc_tm->tm_sec = rtc->sec;
	rtc_tm->tm_min = rtc->min;
	rtc_tm->tm_hour = rtc->hour;
	rtc_tm->tm_mday = rtc->date;
	rtc_tm->tm_mon = rtc->month;
	rtc_tm->tm_year = rtc->year;
	rtc->control &= ~M48T35_RTC_READ;
	spin_unlock_irq(&rtc_lock);

	rtc_tm->tm_sec = BCD2BIN(rtc_tm->tm_sec);
	rtc_tm->tm_min = BCD2BIN(rtc_tm->tm_min);
	rtc_tm->tm_hour = BCD2BIN(rtc_tm->tm_hour);
	rtc_tm->tm_mday = BCD2BIN(rtc_tm->tm_mday);
	rtc_tm->tm_mon = BCD2BIN(rtc_tm->tm_mon);
	rtc_tm->tm_year = BCD2BIN(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 += (epoch - 1900)) <= 69)
		rtc_tm->tm_year += 100;

	rtc_tm->tm_mon--;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Driver for the SGS-Thomson M48T35 Timekeeper RAM chip
	3	*
	4	* Real Time Clock interface for Linux
	5	*
	6	* TODO: Implement periodic interrupts.
	7	*
	8	* Copyright (C) 2000 Silicon Graphics, Inc.
	9	* Written by Ulf Carlsson ([email protected])
	10	*
	11	* Based on code written by Paul Gortmaker.
	12	*
	13	* This driver allows use of the real time clock (built into
	14	* nearly all computers) from user space. It exports the /dev/rtc
	15	* interface supporting various ioctl() and also the /proc/rtc
	16	* pseudo-file for status information.
	17	*
	18	* This program is free software; you can redistribute it and/or
	19	* modify it under the terms of the GNU General Public License
	20	* as published by the Free Software Foundation; either version
	21	* 2 of the License, or (at your option) any later version.
	22	*
	23	*/
	24
	25	#define RTC_VERSION "1.09b"
	26
	27	#include <linux/bcd.h>
	28	#include <linux/module.h>
	29	#include <linux/kernel.h>
b0e54f7c	30	#include <linux/smp_lock.h>
1da177e4 LT	31	#include <linux/types.h>
	32	#include <linux/miscdevice.h>
	33	#include <linux/ioport.h>
	34	#include <linux/fcntl.h>
	35	#include <linux/rtc.h>
	36	#include <linux/init.h>
	37	#include <linux/poll.h>
	38	#include <linux/proc_fs.h>
1da177e4 LT	39
	40	#include <asm/m48t35.h>
	41	#include <asm/sn/ioc3.h>
	42	#include <asm/io.h>
	43	#include <asm/uaccess.h>
	44	#include <asm/system.h>
	45	#include <asm/sn/klconfig.h>
	46	#include <asm/sn/sn0/ip27.h>
	47	#include <asm/sn/sn0/hub.h>
	48	#include <asm/sn/sn_private.h>
	49
102f4a02 CG	50	static long rtc_ioctl(struct file *filp, unsigned int cmd,
102f4a02 CG	51	unsigned long arg);
1da177e4 LT	52
	53	static int rtc_read_proc(char page, char *start, off_t off,
	54	int count, int eof, void data);
	55
	56	static void get_rtc_time(struct rtc_time *rtc_tm);
	57
	58	/*
	59	* Bits in rtc_status. (6 bits of room for future expansion)
	60	*/
	61
	62	#define RTC_IS_OPEN 0x01 /* means /dev/rtc is in use */
	63	#define RTC_TIMER_ON 0x02 /* missed irq timer active */
	64
	65	static unsigned char rtc_status; /* bitmapped status byte. */
	66	static unsigned long rtc_freq; /* Current periodic IRQ rate */
	67	static struct m48t35_rtc *rtc;
	68
	69	/*
	70	* If this driver ever becomes modularised, it will be really nice
	71	* to make the epoch retain its value across module reload...
	72	*/
	73
	74	static unsigned long epoch = 1970; /* year corresponding to 0x00 */
	75
	76	static const unsigned char days_in_mo[] =
	77	{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
	78
102f4a02	79	static long rtc_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
1da177e4 LT	80	{
	81
	82	struct rtc_time wtime;
	83
	84	switch (cmd) {
	85	case RTC_RD_TIME: /* Read the time/date from RTC */
	86	{
	87	get_rtc_time(&wtime);
	88	break;
	89	}
	90	case RTC_SET_TIME: /* Set the RTC */
	91	{
	92	struct rtc_time rtc_tm;
	93	unsigned char mon, day, hrs, min, sec, leap_yr;
	94	unsigned int yrs;
	95
	96	if (!capable(CAP_SYS_TIME))
	97	return -EACCES;
	98
	99	if (copy_from_user(&rtc_tm, (struct rtc_time*)arg,
	100	sizeof(struct rtc_time)))
	101	return -EFAULT;
	102
	103	yrs = rtc_tm.tm_year + 1900;
	104	mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
	105	day = rtc_tm.tm_mday;
	106	hrs = rtc_tm.tm_hour;
	107	min = rtc_tm.tm_min;
	108	sec = rtc_tm.tm_sec;
	109
	110	if (yrs < 1970)
	111	return -EINVAL;
	112
	113	leap_yr = ((!(yrs % 4) && (yrs % 100)) \|\| !(yrs % 400));
	114
	115	if ((mon > 12) \|\| (day == 0))
	116	return -EINVAL;
	117
	118	if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
	119	return -EINVAL;
	120
	121	if ((hrs >= 24) \|\| (min >= 60) \|\| (sec >= 60))
	122	return -EINVAL;
	123
	124	if ((yrs -= epoch) > 255) /* They are unsigned */
	125	return -EINVAL;
	126
	127	if (yrs > 169)
	128	return -EINVAL;
	129
	130	if (yrs >= 100)
	131	yrs -= 100;
	132
	133	sec = BIN2BCD(sec);
	134	min = BIN2BCD(min);
	135	hrs = BIN2BCD(hrs);
	136	day = BIN2BCD(day);
	137	mon = BIN2BCD(mon);
	138	yrs = BIN2BCD(yrs);
	139
	140	spin_lock_irq(&rtc_lock);
	141	rtc->control \|= M48T35_RTC_SET;
	142	rtc->year = yrs;
	143	rtc->month = mon;
144	rtc->date = day;
145	rtc->hour = hrs;
146	rtc->min = min;
147	rtc->sec = sec;
148	rtc->control &= ~M48T35_RTC_SET;
149	spin_unlock_irq(&rtc_lock);
150
151	return 0;
152	}
153	default:
154	return -EINVAL;
155	}
156	return copy_to_user((void *)arg, &wtime, sizeof wtime) ? -EFAULT : 0;
157	}
158
159	/*
160	* We enforce only one user at a time here with the open/close.
161	* Also clear the previous interrupt data on an open, and clean
162	* up things on a close.
163	*/
164
165	static int rtc_open(struct inode inode, struct file file)
166	{
b0e54f7c	167	lock_kernel();
1da177e4 LT	168	spin_lock_irq(&rtc_lock);
	169
	170	if (rtc_status & RTC_IS_OPEN) {
	171	spin_unlock_irq(&rtc_lock);
b0e54f7c	172	unlock_kernel();
1da177e4 LT	173	return -EBUSY;
	174	}
	175
	176	rtc_status \|= RTC_IS_OPEN;
	177	spin_unlock_irq(&rtc_lock);
b0e54f7c	178	unlock_kernel();
1da177e4 LT	179
	180	return 0;
	181	}
	182
	183	static int rtc_release(struct inode inode, struct file file)
	184	{
	185	/*
	186	* Turn off all interrupts once the device is no longer
	187	* in use, and clear the data.
	188	*/
	189
	190	spin_lock_irq(&rtc_lock);
	191	rtc_status &= ~RTC_IS_OPEN;
	192	spin_unlock_irq(&rtc_lock);
	193
	194	return 0;
	195	}
	196
	197	/*
	198	* The various file operations we support.
	199	*/
	200
62322d25	201	static const struct file_operations rtc_fops = {
1da177e4	202	.owner = THIS_MODULE,
102f4a02	203	.unlocked_ioctl = rtc_ioctl,
1da177e4 LT	204	.open = rtc_open,
	205	.release = rtc_release,
	206	};
	207
	208	static struct miscdevice rtc_dev=
	209	{
	210	RTC_MINOR,
	211	"rtc",
	212	&rtc_fops
	213	};
	214
	215	static int __init rtc_init(void)
	216	{
	217	rtc = (struct m48t35_rtc *)
	218	(KL_CONFIG_CH_CONS_INFO(master_nasid)->memory_base + IOC3_BYTEBUS_DEV0);
	219
	220	printk(KERN_INFO "Real Time Clock Driver v%s\n", RTC_VERSION);
	221	if (misc_register(&rtc_dev)) {
	222	printk(KERN_ERR "rtc: cannot register misc device.\n");
	223	return -ENODEV;
	224	}
	225	if (!create_proc_read_entry("driver/rtc", 0, NULL, rtc_read_proc, NULL)) {
	226	printk(KERN_ERR "rtc: cannot create /proc/rtc.\n");
	227	misc_deregister(&rtc_dev);
	228	return -ENOENT;
	229	}
	230
	231	rtc_freq = 1024;
	232
	233	return 0;
	234	}
	235
	236	static void __exit rtc_exit (void)
	237	{
	238	/* interrupts and timer disabled at this point by rtc_release */
	239
	240	remove_proc_entry ("rtc", NULL);
	241	misc_deregister(&rtc_dev);
	242	}
	243
	244	module_init(rtc_init);
	245	module_exit(rtc_exit);
	246
	247	/*
	248	* Info exported via "/proc/rtc".
	249	*/
	250
	251	static int rtc_get_status(char *buf)
	252	{
	253	char *p;
	254	struct rtc_time tm;
	255
	256	/*
	257	* Just emulate the standard /proc/rtc
	258	*/
	259
	260	p = buf;
	261
	262	get_rtc_time(&tm);
	263
	264	/*
	265	* There is no way to tell if the luser has the RTC set for local
	266	* time or for Universal Standard Time (GMT). Probably local though.
	267	*/
268	p += sprintf(p,
269	"rtc_time\t: %02d:%02d:%02d\n"
270	"rtc_date\t: %04d-%02d-%02d\n"
271	"rtc_epoch\t: %04lu\n"
272	"24hr\t\t: yes\n",
273	tm.tm_hour, tm.tm_min, tm.tm_sec,
274	tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, epoch);
275
276	return p - buf;
277	}
278
279	static int rtc_read_proc(char page, char *start, off_t off,
280	int count, int eof, void data)
281	{
282	int len = rtc_get_status(page);
283	if (len <= off+count) *eof = 1;
284	*start = page + off;
285	len -= off;
286	if (len>count) len = count;
287	if (len<0) len = 0;
288	return len;
289	}
290
291	static void get_rtc_time(struct rtc_time *rtc_tm)
292	{
293	/*
294	* Do we need to wait for the last update to finish?
295	*/
296
297	/*
298	* Only the values that we read from the RTC are set. We leave
299	* tm_wday, tm_yday and tm_isdst untouched. Even though the
300	* RTC has RTC_DAY_OF_WEEK, we ignore it, as it is only updated
301	* by the RTC when initially set to a non-zero value.
302	*/
303	spin_lock_irq(&rtc_lock);
304	rtc->control \|= M48T35_RTC_READ;
305	rtc_tm->tm_sec = rtc->sec;
306	rtc_tm->tm_min = rtc->min;
307	rtc_tm->tm_hour = rtc->hour;
308	rtc_tm->tm_mday = rtc->date;
309	rtc_tm->tm_mon = rtc->month;
310	rtc_tm->tm_year = rtc->year;
311	rtc->control &= ~M48T35_RTC_READ;
312	spin_unlock_irq(&rtc_lock);
313
314	rtc_tm->tm_sec = BCD2BIN(rtc_tm->tm_sec);
315	rtc_tm->tm_min = BCD2BIN(rtc_tm->tm_min);
316	rtc_tm->tm_hour = BCD2BIN(rtc_tm->tm_hour);
317	rtc_tm->tm_mday = BCD2BIN(rtc_tm->tm_mday);
318	rtc_tm->tm_mon = BCD2BIN(rtc_tm->tm_mon);
319	rtc_tm->tm_year = BCD2BIN(rtc_tm->tm_year);
320
321	/*
322	* Account for differences between how the RTC uses the values
323	* and how they are defined in a struct rtc_time;
324	*/
325	if ((rtc_tm->tm_year += (epoch - 1900)) <= 69)
326	rtc_tm->tm_year += 100;
327
328	rtc_tm->tm_mon--;
329	}