[GitHub/mt8127/android_kernel_alcatel_ttab.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 (ulfc@engr.sgi.com)
 *
 *	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/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)
{
	spin_lock_irq(&rtc_lock);

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

	rtc_status |= RTC_IS_OPEN;
	spin_unlock_irq(&rtc_lock);

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