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

// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2007
 * Larry Johnson, [email protected]
 *
 * based on rtc/m41t11.c which is ...
 *
 * (C) Copyright 2002
 * Andrew May, Viasat Inc, [email protected]
 */

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

/* #define DEBUG 1 */

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

/*
 * 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 = env_get("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 = hextoul(s, 0);

		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");
}
Commit	Line	Data
83d290c5	1	// SPDX-License-Identifier: GPL-2.0+
12618278 LJ	2	/*
	3	* (C) Copyright 2007
	4	* Larry Johnson, [email protected]
	5	*
	6	* based on rtc/m41t11.c which is ...
	7	*
	8	* (C) Copyright 2002
	9	* Andrew May, Viasat Inc, [email protected]
12618278 LJ	10	*/
	11
	12	/*
	13	* STMicroelectronics M41T60 serial access real-time clock
	14	*/
	15
	16	/* #define DEBUG 1 */
	17
	18	#include <common.h>
	19	#include <command.h>
7b51b576	20	#include <env.h>
f7ae49fc	21	#include <log.h>
12618278 LJ	22	#include <rtc.h>
	23	#include <i2c.h>
	24
12618278 LJ	25	/*
	26	* Convert between century and "century bits" (CB1 and CB0). These routines
	27	* assume years are in the range 1900 - 2299.
	28	*/
	29
	30	static unsigned char year2cb(unsigned const year)
	31	{
	32	if (year < 1900 \|\| year >= 2300)
	33	printf("M41T60 RTC: year %d out of range\n", year);
	34
	35	return (year / 100) & 0x3;
	36	}
	37
	38	static unsigned cb2year(unsigned const cb)
	39	{
	40	return 1900 + 100 * ((cb + 1) & 0x3);
	41	}
	42
	43	/*
	44	* These are simple defines for the chip local to here so they aren't too
	45	* verbose. DAY/DATE aren't nice but that is how they are on the data sheet.
	46	*/
	47	#define RTC_SEC 0x0
	48	#define RTC_MIN 0x1
	49	#define RTC_HOUR 0x2
	50	#define RTC_DAY 0x3
	51	#define RTC_DATE 0x4
	52	#define RTC_MONTH 0x5
	53	#define RTC_YEAR 0x6
	54
	55	#define RTC_REG_CNT 7
	56
	57	#define RTC_CTRL 0x7
	58
	59	#if defined(DEBUG)
	60	static void rtc_dump(char const *const label)
	61	{
	62	uchar data[8];
	63
6d0f6bcf	64	if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) {
12618278 LJ	65	printf("I2C read failed in rtc_dump()\n");
	66	return;
	67	}
	68	printf("RTC dump %s: %02X-%02X-%02X-%02X-%02X-%02X-%02X-%02X\n",
	69	label, data[0], data[1], data[2], data[3],
	70	data[4], data[5], data[6], data[7]);
	71	}
	72	#else
	73	#define rtc_dump(label)
	74	#endif
	75
	76	static uchar *rtc_validate(void)
	77	{
	78	/*
	79	* This routine uses the OUT bit and the validity of the time values to
	80	* determine whether there has been an initial power-up since the last
	81	* time the routine was run. It assumes that the OUT bit is not being
	82	* used for any other purpose.
	83	*/
	84	static const uchar daysInMonth[0x13] = {
	85	0x00, 0x31, 0x29, 0x31, 0x30, 0x31, 0x30, 0x31,
	86	0x31, 0x30, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	87	0x31, 0x30, 0x31
	88	};
	89	static uchar data[8];
	90	uchar min, date, month, years;
	91
	92	rtc_dump("begin validate");
6d0f6bcf	93	if (i2c_read(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) {
12618278 LJ	94	printf("I2C read failed in rtc_validate()\n");
	95	return 0;
	96	}
	97	/*
	98	* If the OUT bit is "1", there has been a loss of power, so stop the
	99	* oscillator so it can be "kick-started" as per data sheet.
	100	*/
	101	if (0x00 != (data[RTC_CTRL] & 0x80)) {
	102	printf("M41T60 RTC clock lost power.\n");
	103	data[RTC_SEC] = 0x80;
6d0f6bcf	104	if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_SEC, 1, data, 1)) {
12618278 LJ	105	printf("I2C write failed in rtc_validate()\n");
	106	return 0;
	107	}
	108	}
	109	/*
	110	* If the oscillator is stopped or the date is invalid, then reset the
	111	* OUT bit to "0", reset the date registers, and start the oscillator.
	112	*/
	113	min = data[RTC_MIN] & 0x7F;
	114	date = data[RTC_DATE];
	115	month = data[RTC_MONTH] & 0x3F;
	116	years = data[RTC_YEAR];
	117	if (0x59 < data[RTC_SEC] \|\| 0x09 < (data[RTC_SEC] & 0x0F) \|\|
	118	0x59 < min \|\| 0x09 < (min & 0x0F) \|\|
	119	0x23 < data[RTC_HOUR] \|\| 0x09 < (data[RTC_HOUR] & 0x0F) \|\|
	120	0x07 < data[RTC_DAY] \|\| 0x00 == data[RTC_DAY] \|\|
	121	0x12 < month \|\|
	122	0x99 < years \|\| 0x09 < (years & 0x0F) \|\|
	123	daysInMonth[month] < date \|\| 0x09 < (date & 0x0F) \|\| 0x00 == date \|\|
	124	(0x29 == date && 0x02 == month &&
	125	((0x00 != (years & 0x03)) \|\|
	126	(0x00 == years && 0x00 != (data[RTC_MONTH] & 0xC0))))) {
	127	printf("Resetting M41T60 RTC clock.\n");
	128	/*
	129	* Set to 00:00:00 1900-01-01 (Monday)
	130	*/
	131	data[RTC_SEC] = 0x00;
	132	data[RTC_MIN] &= 0x80; /* preserve OFIE bit */
	133	data[RTC_HOUR] = 0x00;
	134	data[RTC_DAY] = 0x02;
	135	data[RTC_DATE] = 0x01;
	136	data[RTC_MONTH] = 0xC1;
	137	data[RTC_YEAR] = 0x00;
	138	data[RTC_CTRL] &= 0x7F; /* reset OUT bit */
	139
6d0f6bcf	140	if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, sizeof(data))) {
12618278 LJ	141	printf("I2C write failed in rtc_validate()\n");
	142	return 0;
	143	}
	144	}
	145	return data;
	146	}
	147
b73a19e1	148	int rtc_get(struct rtc_time *tmp)
12618278 LJ	149	{
	150	uchar const *const data = rtc_validate();
	151
	152	if (!data)
b73a19e1	153	return -1;
12618278 LJ	154
	155	tmp->tm_sec = bcd2bin(data[RTC_SEC] & 0x7F);
	156	tmp->tm_min = bcd2bin(data[RTC_MIN] & 0x7F);
	157	tmp->tm_hour = bcd2bin(data[RTC_HOUR] & 0x3F);
	158	tmp->tm_mday = bcd2bin(data[RTC_DATE] & 0x3F);
	159	tmp->tm_mon = bcd2bin(data[RTC_MONTH] & 0x1F);
	160	tmp->tm_year = cb2year(data[RTC_MONTH] >> 6) + bcd2bin(data[RTC_YEAR]);
	161	tmp->tm_wday = bcd2bin(data[RTC_DAY] & 0x07) - 1;
	162	tmp->tm_yday = 0;
	163	tmp->tm_isdst = 0;
	164
	165	debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
	166	tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
	167	tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
b73a19e1 YT	168
b73a19e1 YT	169	return 0;
12618278 LJ	170	}
12618278 LJ	171
d1e23194	172	int rtc_set(struct rtc_time *tmp)
12618278 LJ	173	{
	174	uchar *const data = rtc_validate();
	175
	176	if (!data)
d1e23194	177	return -1;
12618278 LJ	178
	179	debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
	180	tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
	181	tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
	182
	183	data[RTC_SEC] = (data[RTC_SEC] & 0x80) \| (bin2bcd(tmp->tm_sec) & 0x7F);
	184	data[RTC_MIN] = (data[RTC_MIN] & 0X80) \| (bin2bcd(tmp->tm_min) & 0X7F);
	185	data[RTC_HOUR] = bin2bcd(tmp->tm_hour) & 0x3F;
	186	data[RTC_DATE] = bin2bcd(tmp->tm_mday) & 0x3F;
	187	data[RTC_MONTH] = bin2bcd(tmp->tm_mon) & 0x1F;
	188	data[RTC_YEAR] = bin2bcd(tmp->tm_year % 100);
	189	data[RTC_MONTH] \|= year2cb(tmp->tm_year) << 6;
	190	data[RTC_DAY] = bin2bcd(tmp->tm_wday + 1) & 0x07;
6d0f6bcf	191	if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, 0, 1, data, RTC_REG_CNT)) {
12618278	192	printf("I2C write failed in rtc_set()\n");
d1e23194	193	return -1;
12618278	194	}
d1e23194 JCPV	195
d1e23194 JCPV	196	return 0;
12618278 LJ	197	}
	198
	199	void rtc_reset(void)
	200	{
	201	uchar *const data = rtc_validate();
00caae6d	202	char const *const s = env_get("rtccal");
12618278 LJ	203
	204	if (!data)
	205	return;
	206
	207	rtc_dump("begin reset");
	208	/*
	209	* If environmental variable "rtccal" is present, it must be a hex value
	210	* between 0x00 and 0x3F, inclusive. The five least-significan bits
	211	* represent the calibration magnitude, and the sixth bit the sign bit.
	212	* If these do not match the contents of the hardware register, that
	213	* register is updated. The value 0x00 imples no correction. Consult
	214	* the M41T60 documentation for further details.
	215	*/
	216	if (s) {
7e5f460e	217	unsigned long const l = hextoul(s, 0);
12618278 LJ	218
	219	if (l <= 0x3F) {
	220	if ((data[RTC_CTRL] & 0x3F) != l) {
10943c9a	221	printf("Setting RTC calibration to 0x%02lX\n",
12618278 LJ	222	l);
	223	data[RTC_CTRL] &= 0xC0;
	224	data[RTC_CTRL] \|= (uchar) l;
	225	}
	226	} else
	227	printf("environment parameter \"rtccal\" not valid: "
	228	"ignoring\n");
	229	}
	230	/*
	231	* Turn off frequency test.
	232	*/
	233	data[RTC_CTRL] &= 0xBF;
6d0f6bcf	234	if (i2c_write(CONFIG_SYS_I2C_RTC_ADDR, RTC_CTRL, 1, data + RTC_CTRL, 1)) {
12618278 LJ	235	printf("I2C write failed in rtc_reset()\n");
	236	return;
	237	}
	238	rtc_dump("end reset");
	239	}