[people/ms/u-boot.git] / drivers / rtc / m41t60.c

/*
 * (C) Copyright 2007
 * Larry Johnson, lrj@acm.org
 *
 * based on rtc/m41t11.c which is ...
 *
 * (C) Copyright 2002
 * Andrew May, Viasat Inc, amay@viasat.com
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

/*
 * STMicroelectronics M41T60 serial access real-time clock
 */

/* #define DEBUG 1 */

#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>

#if defined(CONFIG_SYS_I2C_RTC_ADDR) && defined(CONFIG_CMD_DATE)

/*
 * Convert between century and "century bits" (CB1 and CB0).  These routines
 * assume years are in the range 1900 - 2299.
 */

static unsigned char year2cb(unsigned const year)
{
	if (year < 1900 || year >= 2300)
		printf("M41T60 RTC: year %d out of range\n", year);

	return (year / 100) & 0x3;
}

static unsigned cb2year(unsigned const cb)
{
	return 1900 + 100 * ((cb + 1) & 0x3);
}

/*
 * These are simple defines for the chip local to here so they aren't too
 * verbose.  DAY/DATE aren't nice but that is how they are on the data sheet.
 */
#define RTC_SEC		0x0
#define RTC_MIN		0x1
#define RTC_HOUR	0x2
#define RTC_DAY		0x3
#define RTC_DATE	0x4
#define RTC_MONTH	0x5
#define RTC_YEAR	0x6

#define RTC_REG_CNT	7

#define RTC_CTRL	0x7

#if defined(DEBUG)
static void rtc_dump(char const *const label)
{
	uchar data[8];

	if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) {
		printf("I2C read failed in rtc_dump()\n");
		return;
	}
	printf("RTC dump %s: %02X-%02X-%02X-%02X-%02X-%02X-%02X-%02X\n",
	       label, data[0], data[1], data[2], data[3],
	       data[4], data[5], data[6], data[7]);
}
#else
#define rtc_dump(label)
#endif

static uchar *rtc_validate(void)
{
	/*
	 * This routine uses the OUT bit and the validity of the time values to
	 * determine whether there has been an initial power-up since the last
	 * time the routine was run.  It assumes that the OUT bit is not being
	 * used for any other purpose.
	 */
	static const uchar daysInMonth[0x13] = {
		0x00, 0x31, 0x29, 0x31, 0x30, 0x31, 0x30, 0x31,
		0x31, 0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
		0x31, 0x30, 0x31
	};
	static uchar data[8];
	uchar min, date, month, years;

	rtc_dump("begin validate");
	if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) {
		printf("I2C read failed in rtc_validate()\n");
		return 0;
	}
	/*
	 * If the OUT bit is "1", there has been a loss of power, so stop the
	 * oscillator so it can be "kick-started" as per data sheet.
	 */
	if (0x00 != (data[RTC_CTRL] & 0x80)) {
		printf("M41T60 RTC clock lost power.\n");
		data[RTC_SEC] = 0x80;
		if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC, 1, data, 1)) {
			printf("I2C write failed in rtc_validate()\n");
			return 0;
		}
	}
	/*
	 * If the oscillator is stopped or the date is invalid, then reset the
	 * OUT bit to "0", reset the date registers, and start the oscillator.
	 */
	min = data[RTC_MIN] & 0x7F;
	date = data[RTC_DATE];
	month = data[RTC_MONTH] & 0x3F;
	years = data[RTC_YEAR];
	if (0x59 < data[RTC_SEC] || 0x09 < (data[RTC_SEC] & 0x0F) ||
	    0x59 < min || 0x09 < (min & 0x0F) ||
	    0x23 < data[RTC_HOUR] || 0x09 < (data[RTC_HOUR] & 0x0F) ||
	    0x07 < data[RTC_DAY] || 0x00 == data[RTC_DAY] ||
	    0x12 < month ||
	    0x99 < years || 0x09 < (years & 0x0F) ||
	    daysInMonth[month] < date || 0x09 < (date & 0x0F) || 0x00 == date ||
	    (0x29 == date && 0x02 == month &&
	     ((0x00 != (years & 0x03)) ||
	      (0x00 == years && 0x00 != (data[RTC_MONTH] & 0xC0))))) {
		printf("Resetting M41T60 RTC clock.\n");
		/*
		 * Set to 00:00:00 1900-01-01 (Monday)
		 */
		data[RTC_SEC] = 0x00;
		data[RTC_MIN] &= 0x80;	/* preserve OFIE bit */
		data[RTC_HOUR] = 0x00;
		data[RTC_DAY] = 0x02;
		data[RTC_DATE] = 0x01;
		data[RTC_MONTH] = 0xC1;
		data[RTC_YEAR] = 0x00;
		data[RTC_CTRL] &= 0x7F;	/* reset OUT bit */

		if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) {
			printf("I2C write failed in rtc_validate()\n");
			return 0;
		}
	}
	return data;
}

int rtc_get(struct rtc_time *tmp)
{
	uchar const *const data = rtc_validate();

	if (!data)
		return -1;

	tmp->tm_sec = bcd2bin(data[RTC_SEC] & 0x7F);
	tmp->tm_min = bcd2bin(data[RTC_MIN] & 0x7F);
	tmp->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3F);
	tmp->tm_mday = bcd2bin(data[RTC_DATE] & 0x3F);
	tmp->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1F);
	tmp->tm_year = cb2year(data[RTC_MONTH] >> 6) + bcd2bin(data[RTC_YEAR]);
	tmp->tm_wday = bcd2bin(data[RTC_DAY] & 0x07) - 1;
	tmp->tm_yday = 0;
	tmp->tm_isdst = 0;

	debug("Get DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
	      tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
	      tmp->tm_hour, tmp->tm_min, tmp->tm_sec);

	return 0;
}

int rtc_set(struct rtc_time *tmp)
{
	uchar *const data = rtc_validate();

	if (!data)
		return -1;

	debug("Set DATE: %4d-%02d-%02d (wday=%d)  TIME: %2d:%02d:%02d\n",
	      tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
	      tmp->tm_hour, tmp->tm_min, tmp->tm_sec);

	data[RTC_SEC] = (data[RTC_SEC] & 0x80) | (bin2bcd(tmp->tm_sec) & 0x7F);
	data[RTC_MIN] = (data[RTC_MIN] & 0X80) | (bin2bcd(tmp->tm_min) & 0X7F);
	data[RTC_HOUR] = bin2bcd(tmp->tm_hour) & 0x3F;
	data[RTC_DATE] = bin2bcd(tmp->tm_mday) & 0x3F;
	data[RTC_MONTH] = bin2bcd(tmp->tm_mon) & 0x1F;
	data[RTC_YEAR] = bin2bcd(tmp->tm_year % 100);
	data[RTC_MONTH] |= year2cb(tmp->tm_year) << 6;
	data[RTC_DAY] = bin2bcd(tmp->tm_wday + 1) & 0x07;
	if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, RTC_REG_CNT)) {
		printf("I2C write failed in rtc_set()\n");
		return -1;
	}

	return 0;
}

void rtc_reset(void)
{
	uchar *const data = rtc_validate();
	char const *const s = getenv("rtccal");

	if (!data)
		return;

	rtc_dump("begin reset");
	/*
	 * If environmental variable "rtccal" is present, it must be a hex value
	 * between 0x00 and 0x3F, inclusive.  The five least-significan bits
	 * represent the calibration magnitude, and the sixth bit the sign bit.
	 * If these do not match the contents of the hardware register, that
	 * register is updated.  The value 0x00 imples no correction.  Consult
	 * the M41T60 documentation for further details.
	 */
	if (s) {
		unsigned long const l = simple_strtoul(s, 0, 16);

		if (l <= 0x3F) {
			if ((data[RTC_CTRL] & 0x3F) != l) {
				printf("Setting RTC calibration to 0x%02lX\n",
				       l);
				data[RTC_CTRL] &= 0xC0;
				data[RTC_CTRL] |= (uchar) l;
			}
		} else
			printf("environment parameter \"rtccal\" not valid: "
			       "ignoring\n");
	}
	/*
	 * Turn off frequency test.
	 */
	data[RTC_CTRL] &= 0xBF;
	if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_CTRL, 1, data + RTC_CTRL, 1)) {
		printf("I2C write failed in rtc_reset()\n");
		return;
	}
	rtc_dump("end reset");
}
#endif /* CONFIG_RTC_M41T60 && CONFIG_SYS_I2C_RTC_ADDR && CONFIG_CMD_DATE */
Commit	Line	Data
12618278 LJ	1	/*
	2	* (C) Copyright 2007
	3	* Larry Johnson, lrj@acm.org
	4	*
	5	* based on rtc/m41t11.c which is ...
	6	*
	7	* (C) Copyright 2002
	8	* Andrew May, Viasat Inc, amay@viasat.com
	9	*
1a459660	10	* SPDX-License-Identifier: GPL-2.0+
12618278 LJ	11	*/
	12
	13	/*
	14	* STMicroelectronics M41T60 serial access real-time clock
	15	*/
	16
	17	/* #define DEBUG 1 */
	18
	19	#include <common.h>
	20	#include <command.h>
	21	#include <rtc.h>
	22	#include <i2c.h>
	23
6d0f6bcf	24	#if defined(CONFIG_SYS_I2C_RTC_ADDR) && defined(CONFIG_CMD_DATE)
12618278	25
12618278 LJ	26	/*
	27	* Convert between century and "century bits" (CB1 and CB0). These routines
	28	* assume years are in the range 1900 - 2299.
	29	*/
	30
	31	static unsigned char year2cb(unsigned const year)
	32	{
	33	if (year < 1900 \|\| year >= 2300)
	34	printf("M41T60 RTC: year %d out of range\n", year);
	35
	36	return (year / 100) & 0x3;
	37	}
	38
	39	static unsigned cb2year(unsigned const cb)
	40	{
	41	return 1900 + 100 * ((cb + 1) & 0x3);
	42	}
	43
	44	/*
	45	* These are simple defines for the chip local to here so they aren't too
	46	* verbose. DAY/DATE aren't nice but that is how they are on the data sheet.
	47	*/
	48	#define RTC_SEC 0x0
	49	#define RTC_MIN 0x1
	50	#define RTC_HOUR 0x2
	51	#define RTC_DAY 0x3
	52	#define RTC_DATE 0x4
	53	#define RTC_MONTH 0x5
	54	#define RTC_YEAR 0x6
	55
	56	#define RTC_REG_CNT 7
	57
	58	#define RTC_CTRL 0x7
	59
	60	#if defined(DEBUG)
	61	static void rtc_dump(char const *const label)
	62	{
	63	uchar data[8];
	64
6d0f6bcf	65	if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) {
12618278 LJ	66	printf("I2C read failed in rtc_dump()\n");
	67	return;
	68	}
	69	printf("RTC dump %s: %02X-%02X-%02X-%02X-%02X-%02X-%02X-%02X\n",
	70	label, data[0], data[1], data[2], data[3],
	71	data[4], data[5], data[6], data[7]);
	72	}
	73	#else
	74	#define rtc_dump(label)
	75	#endif
	76
	77	static uchar *rtc_validate(void)
	78	{
	79	/*
	80	* This routine uses the OUT bit and the validity of the time values to
	81	* determine whether there has been an initial power-up since the last
	82	* time the routine was run. It assumes that the OUT bit is not being
	83	* used for any other purpose.
	84	*/
	85	static const uchar daysInMonth[0x13] = {
	86	0x00, 0x31, 0x29, 0x31, 0x30, 0x31, 0x30, 0x31,
	87	0x31, 0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	88	0x31, 0x30, 0x31
	89	};
	90	static uchar data[8];
	91	uchar min, date, month, years;
	92
	93	rtc_dump("begin validate");
6d0f6bcf	94	if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) {
12618278 LJ	95	printf("I2C read failed in rtc_validate()\n");
	96	return 0;
	97	}
	98	/*
	99	* If the OUT bit is "1", there has been a loss of power, so stop the
	100	* oscillator so it can be "kick-started" as per data sheet.
	101	*/
	102	if (0x00 != (data[RTC_CTRL] & 0x80)) {
	103	printf("M41T60 RTC clock lost power.\n");
	104	data[RTC_SEC] = 0x80;
6d0f6bcf	105	if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC, 1, data, 1)) {
12618278 LJ	106	printf("I2C write failed in rtc_validate()\n");
	107	return 0;
	108	}
	109	}
	110	/*
	111	* If the oscillator is stopped or the date is invalid, then reset the
	112	* OUT bit to "0", reset the date registers, and start the oscillator.
	113	*/
	114	min = data[RTC_MIN] & 0x7F;
	115	date = data[RTC_DATE];
	116	month = data[RTC_MONTH] & 0x3F;
	117	years = data[RTC_YEAR];
	118	if (0x59 < data[RTC_SEC] \|\| 0x09 < (data[RTC_SEC] & 0x0F) \|\|
	119	0x59 < min \|\| 0x09 < (min & 0x0F) \|\|
	120	0x23 < data[RTC_HOUR] \|\| 0x09 < (data[RTC_HOUR] & 0x0F) \|\|
	121	0x07 < data[RTC_DAY] \|\| 0x00 == data[RTC_DAY] \|\|
	122	0x12 < month \|\|
	123	0x99 < years \|\| 0x09 < (years & 0x0F) \|\|
	124	daysInMonth[month] < date \|\| 0x09 < (date & 0x0F) \|\| 0x00 == date \|\|
	125	(0x29 == date && 0x02 == month &&
	126	((0x00 != (years & 0x03)) \|\|
	127	(0x00 == years && 0x00 != (data[RTC_MONTH] & 0xC0))))) {
	128	printf("Resetting M41T60 RTC clock.\n");
	129	/*
	130	* Set to 00:00:00 1900-01-01 (Monday)
	131	*/
	132	data[RTC_SEC] = 0x00;
	133	data[RTC_MIN] &= 0x80; /* preserve OFIE bit */
	134	data[RTC_HOUR] = 0x00;
	135	data[RTC_DAY] = 0x02;
	136	data[RTC_DATE] = 0x01;
	137	data[RTC_MONTH] = 0xC1;
	138	data[RTC_YEAR] = 0x00;
	139	data[RTC_CTRL] &= 0x7F; /* reset OUT bit */
	140
6d0f6bcf	141	if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) {
12618278 LJ	142	printf("I2C write failed in rtc_validate()\n");
	143	return 0;
	144	}
	145	}
	146	return data;
	147	}
	148
b73a19e1	149	int rtc_get(struct rtc_time *tmp)
12618278 LJ	150	{
	151	uchar const *const data = rtc_validate();
	152
	153	if (!data)
b73a19e1	154	return -1;
12618278 LJ	155
	156	tmp->tm_sec = bcd2bin(data[RTC_SEC] & 0x7F);
	157	tmp->tm_min = bcd2bin(data[RTC_MIN] & 0x7F);
	158	tmp->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3F);
	159	tmp->tm_mday = bcd2bin(data[RTC_DATE] & 0x3F);
	160	tmp->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1F);
	161	tmp->tm_year = cb2year(data[RTC_MONTH] >> 6) + bcd2bin(data[RTC_YEAR]);
	162	tmp->tm_wday = bcd2bin(data[RTC_DAY] & 0x07) - 1;
	163	tmp->tm_yday = 0;
	164	tmp->tm_isdst = 0;
	165
	166	debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
	167	tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
	168	tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
b73a19e1 YT	169
b73a19e1 YT	170	return 0;
12618278 LJ	171	}
12618278 LJ	172
d1e23194	173	int rtc_set(struct rtc_time *tmp)
12618278 LJ	174	{
	175	uchar *const data = rtc_validate();
	176
	177	if (!data)
d1e23194	178	return -1;
12618278 LJ	179
	180	debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
	181	tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
	182	tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
	183
	184	data[RTC_SEC] = (data[RTC_SEC] & 0x80) \| (bin2bcd(tmp->tm_sec) & 0x7F);
	185	data[RTC_MIN] = (data[RTC_MIN] & 0X80) \| (bin2bcd(tmp->tm_min) & 0X7F);
	186	data[RTC_HOUR] = bin2bcd(tmp->tm_hour) & 0x3F;
	187	data[RTC_DATE] = bin2bcd(tmp->tm_mday) & 0x3F;
	188	data[RTC_MONTH] = bin2bcd(tmp->tm_mon) & 0x1F;
	189	data[RTC_YEAR] = bin2bcd(tmp->tm_year % 100);
	190	data[RTC_MONTH] \|= year2cb(tmp->tm_year) << 6;
	191	data[RTC_DAY] = bin2bcd(tmp->tm_wday + 1) & 0x07;
6d0f6bcf	192	if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, RTC_REG_CNT)) {
12618278	193	printf("I2C write failed in rtc_set()\n");
d1e23194	194	return -1;
12618278	195	}
d1e23194 JCPV	196
d1e23194 JCPV	197	return 0;
12618278 LJ	198	}
	199
	200	void rtc_reset(void)
	201	{
	202	uchar *const data = rtc_validate();
	203	char const *const s = getenv("rtccal");
	204
	205	if (!data)
	206	return;
	207
	208	rtc_dump("begin reset");
	209	/*
	210	* If environmental variable "rtccal" is present, it must be a hex value
	211	* between 0x00 and 0x3F, inclusive. The five least-significan bits
	212	* represent the calibration magnitude, and the sixth bit the sign bit.
	213	* If these do not match the contents of the hardware register, that
	214	* register is updated. The value 0x00 imples no correction. Consult
	215	* the M41T60 documentation for further details.
	216	*/
	217	if (s) {
	218	unsigned long const l = simple_strtoul(s, 0, 16);
	219
	220	if (l <= 0x3F) {
	221	if ((data[RTC_CTRL] & 0x3F) != l) {
10943c9a	222	printf("Setting RTC calibration to 0x%02lX\n",
12618278 LJ	223	l);
	224	data[RTC_CTRL] &= 0xC0;
	225	data[RTC_CTRL] \|= (uchar) l;
	226	}
	227	} else
	228	printf("environment parameter \"rtccal\" not valid: "
	229	"ignoring\n");
	230	}
	231	/*
	232	* Turn off frequency test.
	233	*/
	234	data[RTC_CTRL] &= 0xBF;
6d0f6bcf	235	if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_CTRL, 1, data + RTC_CTRL, 1)) {
12618278 LJ	236	printf("I2C write failed in rtc_reset()\n");
	237	return;
	238	}
	239	rtc_dump("end reset");
	240	}
6d0f6bcf	241	#endif /* CONFIG_RTC_M41T60 && CONFIG_SYS_I2C_RTC_ADDR && CONFIG_CMD_DATE */