[deliverable/linux.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/config.h>

#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 <asm/uaccess.h>
#include <asm/system.h>
#include <asm/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 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);
	local_irq_disable();

	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);

	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 <= 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 int
rtc_ioctl(struct inode *inode, 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));
			get_rtc_time(&rtc_tm);
			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) */

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

			local_irq_save(flags);
			local_irq_disable();
			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);

			/* 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;

			tcs_val = RTC_TCR_PATTERN | (tcs_val & 0x0F);
			ds1302_writereg(RTC_TRICKLECHARGER, tcs_val);
			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 struct file_operations rtc_fops = {
	.owner		= THIS_MODULE,
	.ioctl		= rtc_ioctl,
};

/* 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
	15	#include <linux/config.h>
	16
	17	#include <linux/fs.h>
	18	#include <linux/init.h>
	19	#include <linux/mm.h>
	20	#include <linux/module.h>
	21	#include <linux/miscdevice.h>
	22	#include <linux/delay.h>
	23	#include <linux/bcd.h>
	24
	25	#include <asm/uaccess.h>
	26	#include <asm/system.h>
	27	#include <asm/io.h>
	28	#include <asm/rtc.h>
	29	#if defined(CONFIG_M32R)
	30	#include <asm/m32r.h>
	31	#endif
	32
	33	#define RTC_MAJOR_NR 121 /* local major, change later */
	34
	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);
124	local_irq_disable();
125
126	rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
127	rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
128	rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
129	rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
130	rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
131	rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
132
133	local_irq_restore(flags);
134
135	BCD_TO_BIN(rtc_tm->tm_sec);
136	BCD_TO_BIN(rtc_tm->tm_min);
137	BCD_TO_BIN(rtc_tm->tm_hour);
138	BCD_TO_BIN(rtc_tm->tm_mday);
139	BCD_TO_BIN(rtc_tm->tm_mon);
140	BCD_TO_BIN(rtc_tm->tm_year);
141
142	/*
143	* Account for differences between how the RTC uses the values
144	* and how they are defined in a struct rtc_time;
145	*/
146
147	if (rtc_tm->tm_year <= 69)
148	rtc_tm->tm_year += 100;
149
150	rtc_tm->tm_mon--;
151	}
152
153	static unsigned char days_in_mo[] =
154	{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
155
156	/* ioctl that supports RTC_RD_TIME and RTC_SET_TIME (read and set time/date). */
157
158	static int
159	rtc_ioctl(struct inode inode, struct file file, unsigned int cmd,
160	unsigned long arg)
161	{
162	unsigned long flags;
163
164	switch(cmd) {
165	case RTC_RD_TIME: /* read the time/date from RTC */
166	{
167	struct rtc_time rtc_tm;
168
169	memset(&rtc_tm, 0, sizeof (struct rtc_time));
170	get_rtc_time(&rtc_tm);
171	if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time)))
172	return -EFAULT;
173	return 0;
174	}
175
176	case RTC_SET_TIME: /* set the RTC */
177	{
178	struct rtc_time rtc_tm;
179	unsigned char mon, day, hrs, min, sec, leap_yr;
180	unsigned int yrs;
181
182	if (!capable(CAP_SYS_TIME))
183	return -EPERM;
184
185	if (copy_from_user(&rtc_tm, (struct rtc_time*)arg, sizeof(struct rtc_time)))
186	return -EFAULT;
187
188	yrs = rtc_tm.tm_year + 1900;
189	mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
190	day = rtc_tm.tm_mday;
191	hrs = rtc_tm.tm_hour;
192	min = rtc_tm.tm_min;
193	sec = rtc_tm.tm_sec;
194
195
196	if ((yrs < 1970) \|\| (yrs > 2069))
197	return -EINVAL;
198
199	leap_yr = ((!(yrs % 4) && (yrs % 100)) \|\| !(yrs % 400));
200
201	if ((mon > 12) \|\| (day == 0))
202	return -EINVAL;
203
204	if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
205	return -EINVAL;
206
207	if ((hrs >= 24) \|\| (min >= 60) \|\| (sec >= 60))
208	return -EINVAL;
209
210	if (yrs >= 2000)
211	yrs -= 2000; /* RTC (0, 1, ... 69) */
212	else
213	yrs -= 1900; /* RTC (70, 71, ... 99) */
214
215	BIN_TO_BCD(sec);
216	BIN_TO_BCD(min);
217	BIN_TO_BCD(hrs);
218	BIN_TO_BCD(day);
219	BIN_TO_BCD(mon);
220	BIN_TO_BCD(yrs);
221
222	local_irq_save(flags);
223	local_irq_disable();
224	CMOS_WRITE(yrs, RTC_YEAR);
225	CMOS_WRITE(mon, RTC_MONTH);
226	CMOS_WRITE(day, RTC_DAY_OF_MONTH);
227	CMOS_WRITE(hrs, RTC_HOURS);
228	CMOS_WRITE(min, RTC_MINUTES);
229	CMOS_WRITE(sec, RTC_SECONDS);
230	local_irq_restore(flags);
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
250	tcs_val = RTC_TCR_PATTERN \| (tcs_val & 0x0F);
251	ds1302_writereg(RTC_TRICKLECHARGER, tcs_val);
252	return 0;
253	}
254	default:
255	return -EINVAL;
256	}
257	}
258
259	int
260	get_rtc_status(char *buf)
261	{
262	char *p;
263	struct rtc_time tm;
264
265	p = buf;
266
267	get_rtc_time(&tm);
268
269	/*
270	* There is no way to tell if the luser has the RTC set for local
271	* time or for Universal Standard Time (GMT). Probably local though.
272	*/
273
274	p += sprintf(p,
275	"rtc_time\t: %02d:%02d:%02d\n"
276	"rtc_date\t: %04d-%02d-%02d\n",
277	tm.tm_hour, tm.tm_min, tm.tm_sec,
278	tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
279
280	return p - buf;
281	}
282
283
284	/* The various file operations we support. */
285
286	static struct file_operations rtc_fops = {
287	.owner = THIS_MODULE,
288	.ioctl = rtc_ioctl,
289	};
290
291	/* Probe for the chip by writing something to its RAM and try reading it back. */
292
293	#define MAGIC_PATTERN 0x42
294
295	static int __init
296	ds1302_probe(void)
297	{
298	int retval, res, baur;
299
300	baur=(boot_cpu_data.bus_clock/(210001000));
301
302	printk("%s: Set PLD_RTCBAUR = %d\n", ds1302_name,baur);
303
304	outw(0x0000,(unsigned long)PLD_RTCCR);
305	outw(0x0000,(unsigned long)PLD_RTCRSTODT);
306	outw(baur,(unsigned long)PLD_RTCBAUR);
307
308	/* Try to talk to timekeeper. */
309
310	ds1302_wenable();
311	/* write RAM byte 0 */
312	/* write something magic */
313	out_byte_rtc(0xc0,MAGIC_PATTERN);
314
315	/* read RAM byte 0 */
316	if((res = in_byte_rtc(0xc1)) == MAGIC_PATTERN) {
317	char buf[100];
318	ds1302_wdisable();
319	printk("%s: RTC found.\n", ds1302_name);
320	get_rtc_status(buf);
321	printk(buf);
322	retval = 1;
323	} else {
324	printk("%s: RTC not found.\n", ds1302_name);
325	retval = 0;
326	}
327
328	return retval;
329	}
330
331
332	/* Just probe for the RTC and register the device to handle the ioctl needed. */
333
334	int __init
335	ds1302_init(void)
336	{
337	if (!ds1302_probe()) {
338	return -1;
339	}
340	return 0;
341	}
342
343	static int __init ds1302_register(void)
344	{
345	ds1302_init();
346	if (register_chrdev(RTC_MAJOR_NR, ds1302_name, &rtc_fops)) {
347	printk(KERN_INFO "%s: unable to get major %d for rtc\n",
348	ds1302_name, RTC_MAJOR_NR);
349	return -1;
350	}
351	return 0;
352	}
353
354	module_init(ds1302_register);