[mirror_ubuntu-zesty-kernel.git] / drivers / char / ds1302.c

/*!***************************************************************************
*!
*! FILE NAME  : ds1302.c
*!
*! DESCRIPTION: Implements an interface for the DS1302 RTC
*!
*! Functions exported: ds1302_readreg, ds1302_writereg, ds1302_init, get_rtc_status
*!
*! ---------------------------------------------------------------------------
*!
*! (C) Copyright 1999, 2000, 2001  Axis Communications AB, LUND, SWEDEN
*!
*!***************************************************************************/


#include <linux/fs.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <linux/bcd.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/io.h>

#include <asm/rtc.h>
#if defined(CONFIG_M32R)
#include <asm/m32r.h>
#endif

#define RTC_MAJOR_NR 121 /* local major, change later */

static DEFINE_MUTEX(rtc_mutex);
static const char ds1302_name[] = "ds1302";

/* Send 8 bits. */
static void
out_byte_rtc(unsigned int reg_addr, unsigned char x)
{
	//RST H
	outw(0x0001,(unsigned long)PLD_RTCRSTODT);
	//write data
	outw(((x<<8)|(reg_addr&0xff)),(unsigned long)PLD_RTCWRDATA);
	//WE
	outw(0x0002,(unsigned long)PLD_RTCCR);
	//wait
	while(inw((unsigned long)PLD_RTCCR));

	//RST L
	outw(0x0000,(unsigned long)PLD_RTCRSTODT);

}

static unsigned char
in_byte_rtc(unsigned int reg_addr)
{
	unsigned char retval;

	//RST H
	outw(0x0001,(unsigned long)PLD_RTCRSTODT);
	//write data
	outw((reg_addr&0xff),(unsigned long)PLD_RTCRDDATA);
	//RE
	outw(0x0001,(unsigned long)PLD_RTCCR);
	//wait
	while(inw((unsigned long)PLD_RTCCR));

	//read data
	retval=(inw((unsigned long)PLD_RTCRDDATA) & 0xff00)>>8;

	//RST L
	outw(0x0000,(unsigned long)PLD_RTCRSTODT);

	return retval;
}

/* Enable writing. */

static void
ds1302_wenable(void)
{
	out_byte_rtc(0x8e,0x00);
}

/* Disable writing. */

static void
ds1302_wdisable(void)
{
	out_byte_rtc(0x8e,0x80);
}


/* Read a byte from the selected register in the DS1302. */

unsigned char
ds1302_readreg(int reg)
{
	unsigned char x;

	x=in_byte_rtc((0x81 | (reg << 1))); /* read register */

	return x;
}

/* Write a byte to the selected register. */

void
ds1302_writereg(int reg, unsigned char val)
{
	ds1302_wenable();
	out_byte_rtc((0x80 | (reg << 1)),val);
	ds1302_wdisable();
}

void
get_rtc_time(struct rtc_time *rtc_tm)
{
	unsigned long flags;

	local_irq_save(flags);

	rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
	rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
	rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
	rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
	rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
	rtc_tm->tm_year = CMOS_READ(RTC_YEAR);

	local_irq_restore(flags);

	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 <= 69)
		rtc_tm->tm_year += 100;

	rtc_tm->tm_mon--;
}

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

/* ioctl that supports RTC_RD_TIME and RTC_SET_TIME (read and set time/date). */

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

	switch(cmd) {
		case RTC_RD_TIME:	/* read the time/date from RTC	*/
		{
			struct rtc_time rtc_tm;

			memset(&rtc_tm, 0, sizeof (struct rtc_time));
			mutex_lock(&rtc_mutex);
			get_rtc_time(&rtc_tm);
			mutex_unlock(&rtc_mutex);
			if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time)))
				return -EFAULT;
			return 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_TIME))
				return -EPERM;

			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) || (yrs > 2069))
				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 >= 2000)
				yrs -= 2000;	/* RTC (0, 1, ... 69) */
			else
				yrs -= 1900;	/* RTC (70, 71, ... 99) */

			sec = bin2bcd(sec);
			min = bin2bcd(min);
			hrs = bin2bcd(hrs);
			day = bin2bcd(day);
			mon = bin2bcd(mon);
			yrs = bin2bcd(yrs);

			mutex_lock(&rtc_mutex);
			local_irq_save(flags);
			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);
			local_irq_restore(flags);
			mutex_unlock(&rtc_mutex);

			/* Notice that at this point, the RTC is updated but
			 * the kernel is still running with the old time.
			 * You need to set that separately with settimeofday
			 * or adjtimex.
			 */
			return 0;
		}

		case RTC_SET_CHARGE: /* set the RTC TRICKLE CHARGE register */
		{
			int tcs_val;

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

			if(copy_from_user(&tcs_val, (int*)arg, sizeof(int)))
				return -EFAULT;

			mutex_lock(&rtc_mutex);
			tcs_val = RTC_TCR_PATTERN | (tcs_val & 0x0F);
			ds1302_writereg(RTC_TRICKLECHARGER, tcs_val);
			mutex_unlock(&rtc_mutex);
			return 0;
		}
		default:
			return -EINVAL;
	}
}

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

	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",
		tm.tm_hour, tm.tm_min, tm.tm_sec,
		tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);

	return  p - buf;
}


/* The various file operations we support. */

static const struct file_operations rtc_fops = {
	.owner		= THIS_MODULE,
	.unlocked_ioctl	= rtc_ioctl,
	.llseek		= noop_llseek,
};

/* Probe for the chip by writing something to its RAM and try reading it back. */

#define MAGIC_PATTERN 0x42

static int __init
ds1302_probe(void)
{
	int retval, res, baur;

	baur=(boot_cpu_data.bus_clock/(2*1000*1000));

	printk("%s: Set PLD_RTCBAUR = %d\n", ds1302_name,baur);

	outw(0x0000,(unsigned long)PLD_RTCCR);
	outw(0x0000,(unsigned long)PLD_RTCRSTODT);
	outw(baur,(unsigned long)PLD_RTCBAUR);

	/* Try to talk to timekeeper. */

	ds1302_wenable();
	/* write RAM byte 0 */
	/* write something magic */
	out_byte_rtc(0xc0,MAGIC_PATTERN);

	/* read RAM byte 0 */
	if((res = in_byte_rtc(0xc1)) == MAGIC_PATTERN) {
		char buf[100];
		ds1302_wdisable();
		printk("%s: RTC found.\n", ds1302_name);
		get_rtc_status(buf);
		printk(buf);
		retval = 1;
	} else {
		printk("%s: RTC not found.\n", ds1302_name);
		retval = 0;
	}

	return retval;
}


/* Just probe for the RTC and register the device to handle the ioctl needed. */

int __init
ds1302_init(void)
{
	if (!ds1302_probe()) {
		return -1;
  	}
	return 0;
}

static int __init ds1302_register(void)
{
	ds1302_init();
	if (register_chrdev(RTC_MAJOR_NR, ds1302_name, &rtc_fops)) {
		printk(KERN_INFO "%s: unable to get major %d for rtc\n",
		       ds1302_name, RTC_MAJOR_NR);
		return -1;
	}
	return 0;
}

module_init(ds1302_register);
Commit	Line	Data
1da177e4 LT	1	/!**************************************************************************
	2	*!
	3	*! FILE NAME : ds1302.c
	4	*!
	5	*! DESCRIPTION: Implements an interface for the DS1302 RTC
	6	*!
	7	*! Functions exported: ds1302_readreg, ds1302_writereg, ds1302_init, get_rtc_status
	8	*!
	9	*! ---------------------------------------------------------------------------
	10	*!
	11	*! (C) Copyright 1999, 2000, 2001 Axis Communications AB, LUND, SWEDEN
	12	*!
	13	!**************************************************************************/
	14
1da177e4 LT	15
	16	#include <linux/fs.h>
	17	#include <linux/init.h>
	18	#include <linux/mm.h>
	19	#include <linux/module.h>
	20	#include <linux/miscdevice.h>
	21	#include <linux/delay.h>
	22	#include <linux/bcd.h>
613655fa	23	#include <linux/mutex.h>
b8e35919 AC	24	#include <linux/uaccess.h>
b8e35919 AC	25	#include <linux/io.h>
1da177e4	26
1da177e4 LT	27	#include <asm/rtc.h>
	28	#if defined(CONFIG_M32R)
	29	#include <asm/m32r.h>
	30	#endif
	31
	32	#define RTC_MAJOR_NR 121 /* local major, change later */
	33
613655fa	34	static DEFINE_MUTEX(rtc_mutex);
1da177e4 LT	35	static const char ds1302_name[] = "ds1302";
	36
	37	/* Send 8 bits. */
	38	static void
	39	out_byte_rtc(unsigned int reg_addr, unsigned char x)
	40	{
	41	//RST H
	42	outw(0x0001,(unsigned long)PLD_RTCRSTODT);
	43	//write data
	44	outw(((x<<8)\|(reg_addr&0xff)),(unsigned long)PLD_RTCWRDATA);
	45	//WE
	46	outw(0x0002,(unsigned long)PLD_RTCCR);
	47	//wait
	48	while(inw((unsigned long)PLD_RTCCR));
	49
	50	//RST L
	51	outw(0x0000,(unsigned long)PLD_RTCRSTODT);
	52
	53	}
	54
	55	static unsigned char
	56	in_byte_rtc(unsigned int reg_addr)
	57	{
	58	unsigned char retval;
	59
	60	//RST H
	61	outw(0x0001,(unsigned long)PLD_RTCRSTODT);
	62	//write data
	63	outw((reg_addr&0xff),(unsigned long)PLD_RTCRDDATA);
	64	//RE
	65	outw(0x0001,(unsigned long)PLD_RTCCR);
	66	//wait
	67	while(inw((unsigned long)PLD_RTCCR));
	68
	69	//read data
	70	retval=(inw((unsigned long)PLD_RTCRDDATA) & 0xff00)>>8;
	71
	72	//RST L
	73	outw(0x0000,(unsigned long)PLD_RTCRSTODT);
	74
	75	return retval;
	76	}
	77
	78	/* Enable writing. */
	79
	80	static void
	81	ds1302_wenable(void)
	82	{
	83	out_byte_rtc(0x8e,0x00);
	84	}
	85
	86	/* Disable writing. */
	87
	88	static void
	89	ds1302_wdisable(void)
	90	{
	91	out_byte_rtc(0x8e,0x80);
	92	}
	93
	94
	95
	96	/* Read a byte from the selected register in the DS1302. */
	97
	98	unsigned char
99	ds1302_readreg(int reg)
100	{
101	unsigned char x;
102
103	x=in_byte_rtc((0x81 \| (reg << 1))); /* read register */
104
105	return x;
106	}
107
108	/* Write a byte to the selected register. */
109
110	void
111	ds1302_writereg(int reg, unsigned char val)
112	{
113	ds1302_wenable();
114	out_byte_rtc((0x80 \| (reg << 1)),val);
115	ds1302_wdisable();
116	}
117
118	void
119	get_rtc_time(struct rtc_time *rtc_tm)
120	{
121	unsigned long flags;
122
123	local_irq_save(flags);
1da177e4 LT	124
	125	rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
	126	rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
	127	rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
	128	rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
	129	rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
	130	rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
	131
	132	local_irq_restore(flags);
	133
357c6e63 AB	134	rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
	135	rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
	136	rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
	137	rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
	138	rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
	139	rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
1da177e4 LT	140
	141	/*
	142	* Account for differences between how the RTC uses the values
	143	* and how they are defined in a struct rtc_time;
	144	*/
	145
	146	if (rtc_tm->tm_year <= 69)
	147	rtc_tm->tm_year += 100;
	148
	149	rtc_tm->tm_mon--;
	150	}
	151
	152	static unsigned char days_in_mo[] =
	153	{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
	154
	155	/* ioctl that supports RTC_RD_TIME and RTC_SET_TIME (read and set time/date). */
	156
b8e35919	157	static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1da177e4 LT	158	{
	159	unsigned long flags;
	160
	161	switch(cmd) {
	162	case RTC_RD_TIME: /* read the time/date from RTC */
	163	{
	164	struct rtc_time rtc_tm;
	165
	166	memset(&rtc_tm, 0, sizeof (struct rtc_time));
613655fa	167	mutex_lock(&rtc_mutex);
1da177e4	168	get_rtc_time(&rtc_tm);
613655fa	169	mutex_unlock(&rtc_mutex);
1da177e4 LT	170	if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time)))
	171	return -EFAULT;
	172	return 0;
	173	}
	174
	175	case RTC_SET_TIME: /* set the RTC */
	176	{
	177	struct rtc_time rtc_tm;
	178	unsigned char mon, day, hrs, min, sec, leap_yr;
	179	unsigned int yrs;
	180
	181	if (!capable(CAP_SYS_TIME))
	182	return -EPERM;
	183
	184	if (copy_from_user(&rtc_tm, (struct rtc_time*)arg, sizeof(struct rtc_time)))
	185	return -EFAULT;
	186
	187	yrs = rtc_tm.tm_year + 1900;
	188	mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
	189	day = rtc_tm.tm_mday;
	190	hrs = rtc_tm.tm_hour;
	191	min = rtc_tm.tm_min;
	192	sec = rtc_tm.tm_sec;
	193
	194
	195	if ((yrs < 1970) \|\| (yrs > 2069))
	196	return -EINVAL;
	197
	198	leap_yr = ((!(yrs % 4) && (yrs % 100)) \|\| !(yrs % 400));
	199
	200	if ((mon > 12) \|\| (day == 0))
	201	return -EINVAL;
	202
	203	if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
	204	return -EINVAL;
	205
	206	if ((hrs >= 24) \|\| (min >= 60) \|\| (sec >= 60))
	207	return -EINVAL;
	208
	209	if (yrs >= 2000)
	210	yrs -= 2000; /* RTC (0, 1, ... 69) */
	211	else
	212	yrs -= 1900; /* RTC (70, 71, ... 99) */
	213
357c6e63 AB	214	sec = bin2bcd(sec);
	215	min = bin2bcd(min);
	216	hrs = bin2bcd(hrs);
	217	day = bin2bcd(day);
	218	mon = bin2bcd(mon);
	219	yrs = bin2bcd(yrs);
1da177e4	220
613655fa	221	mutex_lock(&rtc_mutex);
1da177e4	222	local_irq_save(flags);
1da177e4 LT	223	CMOS_WRITE(yrs, RTC_YEAR);
	224	CMOS_WRITE(mon, RTC_MONTH);
	225	CMOS_WRITE(day, RTC_DAY_OF_MONTH);
	226	CMOS_WRITE(hrs, RTC_HOURS);
	227	CMOS_WRITE(min, RTC_MINUTES);
	228	CMOS_WRITE(sec, RTC_SECONDS);
	229	local_irq_restore(flags);
613655fa	230	mutex_unlock(&rtc_mutex);
1da177e4 LT	231
	232	/* Notice that at this point, the RTC is updated but
	233	* the kernel is still running with the old time.
	234	* You need to set that separately with settimeofday
	235	* or adjtimex.
	236	*/
	237	return 0;
	238	}
	239
	240	case RTC_SET_CHARGE: /* set the RTC TRICKLE CHARGE register */
	241	{
	242	int tcs_val;
	243
	244	if (!capable(CAP_SYS_TIME))
	245	return -EPERM;
	246
	247	if(copy_from_user(&tcs_val, (int*)arg, sizeof(int)))
	248	return -EFAULT;
	249
613655fa	250	mutex_lock(&rtc_mutex);
1da177e4 LT	251	tcs_val = RTC_TCR_PATTERN \| (tcs_val & 0x0F);
1da177e4 LT	252	ds1302_writereg(RTC_TRICKLECHARGER, tcs_val);
613655fa	253	mutex_unlock(&rtc_mutex);
1da177e4 LT	254	return 0;
	255	}
	256	default:
	257	return -EINVAL;
	258	}
	259	}
	260
	261	int
	262	get_rtc_status(char *buf)
	263	{
	264	char *p;
	265	struct rtc_time tm;
	266
	267	p = buf;
	268
	269	get_rtc_time(&tm);
	270
	271	/*
	272	* There is no way to tell if the luser has the RTC set for local
	273	* time or for Universal Standard Time (GMT). Probably local though.
	274	*/
	275
	276	p += sprintf(p,
	277	"rtc_time\t: %02d:%02d:%02d\n"
	278	"rtc_date\t: %04d-%02d-%02d\n",
	279	tm.tm_hour, tm.tm_min, tm.tm_sec,
	280	tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
	281
	282	return p - buf;
	283	}
	284
	285
	286	/* The various file operations we support. */
	287
62322d25	288	static const struct file_operations rtc_fops = {
1da177e4	289	.owner = THIS_MODULE,
b8e35919	290	.unlocked_ioctl = rtc_ioctl,
6038f373	291	.llseek = noop_llseek,
1da177e4 LT	292	};
	293
	294	/* Probe for the chip by writing something to its RAM and try reading it back. */
	295
	296	#define MAGIC_PATTERN 0x42
	297
	298	static int __init
	299	ds1302_probe(void)
	300	{
	301	int retval, res, baur;
	302
	303	baur=(boot_cpu_data.bus_clock/(210001000));
	304
	305	printk("%s: Set PLD_RTCBAUR = %d\n", ds1302_name,baur);
	306
	307	outw(0x0000,(unsigned long)PLD_RTCCR);
	308	outw(0x0000,(unsigned long)PLD_RTCRSTODT);
	309	outw(baur,(unsigned long)PLD_RTCBAUR);
	310
	311	/* Try to talk to timekeeper. */
	312
	313	ds1302_wenable();
	314	/* write RAM byte 0 */
	315	/* write something magic */
	316	out_byte_rtc(0xc0,MAGIC_PATTERN);
	317
	318	/* read RAM byte 0 */
	319	if((res = in_byte_rtc(0xc1)) == MAGIC_PATTERN) {
	320	char buf[100];
	321	ds1302_wdisable();
	322	printk("%s: RTC found.\n", ds1302_name);
	323	get_rtc_status(buf);
	324	printk(buf);
	325	retval = 1;
	326	} else {
	327	printk("%s: RTC not found.\n", ds1302_name);
	328	retval = 0;
	329	}
	330
	331	return retval;
	332	}
	333
	334
	335	/* Just probe for the RTC and register the device to handle the ioctl needed. */
	336
	337	int __init
	338	ds1302_init(void)
	339	{
	340	if (!ds1302_probe()) {
	341	return -1;
	342	}
	343	return 0;
	344	}
	345
	346	static int __init ds1302_register(void)
	347	{
	348	ds1302_init();
	349	if (register_chrdev(RTC_MAJOR_NR, ds1302_name, &rtc_fops)) {
	350	printk(KERN_INFO "%s: unable to get major %d for rtc\n",
	351	ds1302_name, RTC_MAJOR_NR);
	352	return -1;
	353	}
	354	return 0;
	355	}
356
357	module_init(ds1302_register);