[J-u-boot.git] / board / bmw / m48t59y.c

/*
 * SGS M48-T59Y TOD/NVRAM Driver
 *
 * (C) Copyright 2000
 * Wolfgang Denk, DENX Software Engineering, [email protected].
 *
 * (C) Copyright 1999, by Curt McDowell, 08-06-99, Broadcom Corp.
 *
 * (C) Copyright 2001, James Dougherty, 07/18/01, Broadcom Corp.
 *
 * See file CREDITS for list of people who contributed to this
 * project.
 *
 * 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.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
 * MA 02111-1307 USA
 */

/*
 * SGS M48-T59Y TOD/NVRAM Driver
 *
 * The SGS M48 an 8K NVRAM starting at offset M48_BASE_ADDR and
 * continuing for 8176 bytes. After that starts the Time-Of-Day (TOD)
 * registers which are used to set/get the internal date/time functions.
 *
 * This module implements Y2K compliance by taking full year numbers
 * and translating back and forth from the TOD 2-digit year.
 *
 * NOTE: for proper interaction with an operating system, the TOD should
 * be used to store Universal Coordinated Time (GMT) and timezone
 * conversions should be used.
 *
 * Here is a diagram of the memory layout:
 *
 * +---------------------------------------------+ 0xffe0a000
 * | Non-volatile memory                         | .
 * |                                             | .
 * | (8176 bytes of Non-volatile memory)         | .
 * |                                             | .
 * +---------------------------------------------+ 0xffe0bff0
 * | Flags                                       |
 * +---------------------------------------------+ 0xffe0bff1
 * | Unused                                      |
 * +---------------------------------------------+ 0xffe0bff2
 * | Alarm Seconds                               |
 * +---------------------------------------------+ 0xffe0bff3
 * | Alarm Minutes                               |
 * +---------------------------------------------+ 0xffe0bff4
 * | Alarm Date                                  |
 * +---------------------------------------------+ 0xffe0bff5
 * | Interrupts                                  |
 * +---------------------------------------------+ 0xffe0bff6
 * | WatchDog                                    |
 * +---------------------------------------------+ 0xffe0bff7
 * | Calibration                                 |
 * +---------------------------------------------+ 0xffe0bff8
 * | Seconds                                     |
 * +---------------------------------------------+ 0xffe0bff9
 * | Minutes                                     |
 * +---------------------------------------------+ 0xffe0bffa
 * | Hours                                       |
 * +---------------------------------------------+ 0xffe0bffb
 * | Day                                         |
 * +---------------------------------------------+ 0xffe0bffc
 * | Date                                        |
 * +---------------------------------------------+ 0xffe0bffd
 * | Month                                       |
 * +---------------------------------------------+ 0xffe0bffe
 * | Year (2 digits only)                        |
 * +---------------------------------------------+ 0xffe0bfff
 */
#include <common.h>
#include <rtc.h>
#include "bmw.h"

/*
 * Imported from mousse.h:
 *
 *   TOD_REG_BASE		Base of m48t59y TOD registers
 *   SYS_TOD_UNPROTECT()	Disable NVRAM write protect
 *   SYS_TOD_PROTECT()		Re-enable NVRAM write protect
 */

#define YEAR		0xf
#define MONTH		0xe
#define DAY		0xd
#define DAY_OF_WEEK	0xc
#define HOUR		0xb
#define MINUTE		0xa
#define SECOND		0x9
#define CONTROL		0x8
#define WATCH		0x7
#define INTCTL		0x6
#define WD_DATE		0x5
#define WD_HOUR		0x4
#define WD_MIN		0x3
#define WD_SEC		0x2
#define _UNUSED		0x1
#define FLAGS		0x0

#define M48_ADDR	((volatile unsigned char *) TOD_REG_BASE)

int m48_tod_init(void)
{
    SYS_TOD_UNPROTECT();

    M48_ADDR[CONTROL] = 0;
    M48_ADDR[WATCH] = 0;
    M48_ADDR[INTCTL] = 0;

    /*
     * If the oscillator is currently stopped (as on a new part shipped
     * from the factory), start it running.
     *
     * Here is an example of the TOD bytes on a brand new M48T59Y part:
     *		00 00 00 00 00 00 00 00 00 88 8c c3 bf c8 f5 01
     */

    if (M48_ADDR[SECOND] & 0x80)
	M48_ADDR[SECOND] = 0;

    /* Is battery low */
    if ( M48_ADDR[FLAGS] & 0x10) {
	 printf("NOTICE: Battery low on Real-Time Clock (replace SNAPHAT).\n");
    }

    SYS_TOD_PROTECT();

    return 0;
}

/*
 * m48_tod_set
 */

static int to_bcd(int value)
{
    return value / 10 * 16 + value % 10;
}

static int from_bcd(int value)
{
    return value / 16 * 10 + value % 16;
}

static int day_of_week(int y, int m, int d)	/* 0-6 ==> Sun-Sat */
{
    static int t[] = {0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4};
    y -= m < 3;
    return (y + y/4 - y/100 + y/400 + t[m-1] + d) % 7;
}

/*
 * Note: the TOD should store the current GMT
 */

int m48_tod_set(int year,		/* 1980-2079 */
		int month,		/* 01-12 */
		int day,		/* 01-31 */
		int hour,		/* 00-23 */
		int minute,		/* 00-59 */
		int second)		/* 00-59 */

{
    SYS_TOD_UNPROTECT();

    M48_ADDR[CONTROL] |= 0x80;	/* Set WRITE bit */

    M48_ADDR[YEAR] = to_bcd(year % 100);
    M48_ADDR[MONTH] = to_bcd(month);
    M48_ADDR[DAY] = to_bcd(day);
    M48_ADDR[DAY_OF_WEEK] = day_of_week(year, month, day) + 1;
    M48_ADDR[HOUR] = to_bcd(hour);
    M48_ADDR[MINUTE] = to_bcd(minute);
    M48_ADDR[SECOND] = to_bcd(second);

    M48_ADDR[CONTROL] &= ~0x80;	/* Clear WRITE bit */

    SYS_TOD_PROTECT();

    return 0;
}

/*
 * Note: the TOD should store the current GMT
 */

int m48_tod_get(int *year,		/* 1980-2079 */
		int *month,		/* 01-12 */
		int *day,		/* 01-31 */
		int *hour,		/* 00-23 */
		int *minute,		/* 00-59 */
		int *second)		/* 00-59 */
{
    int y;

    SYS_TOD_UNPROTECT();

    M48_ADDR[CONTROL] |= 0x40;	/* Set READ bit */

    y = from_bcd(M48_ADDR[YEAR]);
    *year = y < 80 ? 2000 + y : 1900 + y;
    *month = from_bcd(M48_ADDR[MONTH]);
    *day = from_bcd(M48_ADDR[DAY]);
    /* day_of_week = M48_ADDR[DAY_OF_WEEK] & 0xf; */
    *hour = from_bcd(M48_ADDR[HOUR]);
    *minute = from_bcd(M48_ADDR[MINUTE]);
    *second = from_bcd(M48_ADDR[SECOND] & 0x7f);

    M48_ADDR[CONTROL] &= ~0x40;	/* Clear READ bit */

    SYS_TOD_PROTECT();

    return 0;
}

int m48_tod_get_second(void)
{
    return from_bcd(M48_ADDR[SECOND] & 0x7f);
}

/*
 * Watchdog function
 *
 *  If usec is 0, the watchdog timer is disarmed.
 *
 *  If usec is non-zero, the watchdog timer is armed (or re-armed) for
 *    approximately usec microseconds (if the exact requested usec is
 *    not supported by the chip, the next higher available value is used).
 *
 *  Minimum watchdog timeout = 62500 usec
 *  Maximum watchdog timeout = 124 sec (124000000 usec)
 */

void m48_watchdog_arm(int usec)
{
    int		mpy, res;

    SYS_TOD_UNPROTECT();

    if (usec == 0) {
	res = 0;
	mpy = 0;
    } else if (usec < 2000000) {	/* Resolution: 1/16s if below 2s */
	res = 0;
	mpy = (usec + 62499) / 62500;
    } else if (usec < 8000000) {	/* Resolution: 1/4s if below 8s */
	res = 1;
	mpy = (usec + 249999) / 250000;
    } else if (usec < 32000000) {	/* Resolution: 1s if below 32s */
	res = 2;
	mpy = (usec + 999999) / 1000000;
    } else {				/* Resolution: 4s up to 124s */
	res = 3;
	mpy = (usec + 3999999) / 4000000;
	if (mpy > 31)
	    mpy = 31;
    }

    M48_ADDR[WATCH] = (0x80 |		/* Steer to RST signal (IRQ = N/C) */
		       mpy << 2 |
		       res);

    SYS_TOD_PROTECT();
}

/*
 * U-Boot RTC support.
 */
int
rtc_get( struct rtc_time *tmp )
{
	m48_tod_get(&tmp->tm_year,
		    &tmp->tm_mon,
		    &tmp->tm_mday,
		    &tmp->tm_hour,
		    &tmp->tm_min,
		    &tmp->tm_sec);
	tmp->tm_yday = 0;
	tmp->tm_isdst= 0;

#ifdef RTC_DEBUG
	printf( "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 );
#endif

	return 0;
}

int rtc_set( struct rtc_time *tmp )
{
	m48_tod_set(tmp->tm_year,		/* 1980-2079 */
		    tmp->tm_mon,		/* 01-12 */
		    tmp->tm_mday,              /* 01-31 */
		    tmp->tm_hour,		/* 00-23 */
		    tmp->tm_min,		/* 00-59 */
		    tmp->tm_sec);		/* 00-59 */

#ifdef RTC_DEBUG
	printf( "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);
#endif

	return 0;
}

void
rtc_reset (void)
{
  m48_tod_init();
}
Commit	Line	Data
f9087a32 WD	1	/*
	2	* SGS M48-T59Y TOD/NVRAM Driver
	3	*
	4	* (C) Copyright 2000
	5	* Wolfgang Denk, DENX Software Engineering, [email protected].
	6	*
	7	* (C) Copyright 1999, by Curt McDowell, 08-06-99, Broadcom Corp.
	8	*
	9	* (C) Copyright 2001, James Dougherty, 07/18/01, Broadcom Corp.
	10	*
	11	* See file CREDITS for list of people who contributed to this
	12	* project.
	13	*
	14	* This program is free software; you can redistribute it and/or
	15	* modify it under the terms of the GNU General Public License as
	16	* published by the Free Software Foundation; either version 2 of
	17	* the License, or (at your option) any later version.
	18	*
	19	* This program is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	22	* GNU General Public License for more details.
	23	*
	24	* You should have received a copy of the GNU General Public License
	25	* along with this program; if not, write to the Free Software
	26	* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	27	* MA 02111-1307 USA
	28	*/
	29
	30	/*
	31	* SGS M48-T59Y TOD/NVRAM Driver
	32	*
	33	* The SGS M48 an 8K NVRAM starting at offset M48_BASE_ADDR and
	34	* continuing for 8176 bytes. After that starts the Time-Of-Day (TOD)
	35	* registers which are used to set/get the internal date/time functions.
	36	*
	37	* This module implements Y2K compliance by taking full year numbers
	38	* and translating back and forth from the TOD 2-digit year.
	39	*
	40	* NOTE: for proper interaction with an operating system, the TOD should
	41	* be used to store Universal Coordinated Time (GMT) and timezone
	42	* conversions should be used.
	43	*
	44	* Here is a diagram of the memory layout:
	45	*
	46	* +---------------------------------------------+ 0xffe0a000
	47	* \| Non-volatile memory \| .
	48	* \| \| .
	49	* \| (8176 bytes of Non-volatile memory) \| .
	50	* \| \| .
	51	* +---------------------------------------------+ 0xffe0bff0
	52	* \| Flags \|
	53	* +---------------------------------------------+ 0xffe0bff1
	54	* \| Unused \|
	55	* +---------------------------------------------+ 0xffe0bff2
	56	* \| Alarm Seconds \|
	57	* +---------------------------------------------+ 0xffe0bff3
	58	* \| Alarm Minutes \|
	59	* +---------------------------------------------+ 0xffe0bff4
	60	* \| Alarm Date \|
	61	* +---------------------------------------------+ 0xffe0bff5
	62	* \| Interrupts \|
	63	* +---------------------------------------------+ 0xffe0bff6
	64	* \| WatchDog \|
65	* +---------------------------------------------+ 0xffe0bff7
66	* \| Calibration \|
67	* +---------------------------------------------+ 0xffe0bff8
68	* \| Seconds \|
69	* +---------------------------------------------+ 0xffe0bff9
70	* \| Minutes \|
71	* +---------------------------------------------+ 0xffe0bffa
72	* \| Hours \|
73	* +---------------------------------------------+ 0xffe0bffb
74	* \| Day \|
75	* +---------------------------------------------+ 0xffe0bffc
76	* \| Date \|
77	* +---------------------------------------------+ 0xffe0bffd
78	* \| Month \|
79	* +---------------------------------------------+ 0xffe0bffe
80	* \| Year (2 digits only) \|
81	* +---------------------------------------------+ 0xffe0bfff
82	*/
83	#include <common.h>
84	#include <rtc.h>
85	#include "bmw.h"
86
87	/*
88	* Imported from mousse.h:
89	*
90	* TOD_REG_BASE Base of m48t59y TOD registers
91	* SYS_TOD_UNPROTECT() Disable NVRAM write protect
92	* SYS_TOD_PROTECT() Re-enable NVRAM write protect
93	*/
94
95	#define YEAR 0xf
96	#define MONTH 0xe
97	#define DAY 0xd
98	#define DAY_OF_WEEK 0xc
99	#define HOUR 0xb
100	#define MINUTE 0xa
101	#define SECOND 0x9
102	#define CONTROL 0x8
103	#define WATCH 0x7
104	#define INTCTL 0x6
105	#define WD_DATE 0x5
106	#define WD_HOUR 0x4
107	#define WD_MIN 0x3
108	#define WD_SEC 0x2
109	#define _UNUSED 0x1
110	#define FLAGS 0x0
111
112	#define M48_ADDR ((volatile unsigned char *) TOD_REG_BASE)
113
114	int m48_tod_init(void)
115	{
116	SYS_TOD_UNPROTECT();
117
118	M48_ADDR[CONTROL] = 0;
119	M48_ADDR[WATCH] = 0;
120	M48_ADDR[INTCTL] = 0;
121
122	/*
123	* If the oscillator is currently stopped (as on a new part shipped
124	* from the factory), start it running.
125	*
126	* Here is an example of the TOD bytes on a brand new M48T59Y part:
127	* 00 00 00 00 00 00 00 00 00 88 8c c3 bf c8 f5 01
128	*/
129
130	if (M48_ADDR[SECOND] & 0x80)
131	M48_ADDR[SECOND] = 0;
132
133	/* Is battery low */
134	if ( M48_ADDR[FLAGS] & 0x10) {
135	printf("NOTICE: Battery low on Real-Time Clock (replace SNAPHAT).\n");
136	}
137
138	SYS_TOD_PROTECT();
139
140	return 0;
141	}
142
143	/*
144	* m48_tod_set
145	*/
146
147	static int to_bcd(int value)
148	{
149	return value / 10 * 16 + value % 10;
150	}
151
152	static int from_bcd(int value)
153	{
154	return value / 16 * 10 + value % 16;
155	}
156
157	static int day_of_week(int y, int m, int d) /* 0-6 ==> Sun-Sat */
158	{
159	static int t[] = {0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4};
160	y -= m < 3;
161	return (y + y/4 - y/100 + y/400 + t[m-1] + d) % 7;
162	}
163
164	/*
165	* Note: the TOD should store the current GMT
166	*/
167
168	int m48_tod_set(int year, /* 1980-2079 */
169	int month, /* 01-12 */
170	int day, /* 01-31 */
171	int hour, /* 00-23 */
172	int minute, /* 00-59 */
173	int second) /* 00-59 */
174
175	{
176	SYS_TOD_UNPROTECT();
177
178	M48_ADDR[CONTROL] \|= 0x80; /* Set WRITE bit */
179
180	M48_ADDR[YEAR] = to_bcd(year % 100);
181	M48_ADDR[MONTH] = to_bcd(month);
182	M48_ADDR[DAY] = to_bcd(day);
183	M48_ADDR[DAY_OF_WEEK] = day_of_week(year, month, day) + 1;
184	M48_ADDR[HOUR] = to_bcd(hour);
185	M48_ADDR[MINUTE] = to_bcd(minute);
186	M48_ADDR[SECOND] = to_bcd(second);
187
188	M48_ADDR[CONTROL] &= ~0x80; /* Clear WRITE bit */
189
190	SYS_TOD_PROTECT();
191
192	return 0;
193	}
194
195	/*
196	* Note: the TOD should store the current GMT
197	*/
198
199	int m48_tod_get(int year, / 1980-2079 */
200	int month, / 01-12 */
201	int day, / 01-31 */
202	int hour, / 00-23 */
203	int minute, / 00-59 */
204	int second) / 00-59 */
205	{
206	int y;
207
208	SYS_TOD_UNPROTECT();
209
210	M48_ADDR[CONTROL] \|= 0x40; /* Set READ bit */
211
212	y = from_bcd(M48_ADDR[YEAR]);
213	*year = y < 80 ? 2000 + y : 1900 + y;
214	*month = from_bcd(M48_ADDR[MONTH]);
215	*day = from_bcd(M48_ADDR[DAY]);
216	/* day_of_week = M48_ADDR[DAY_OF_WEEK] & 0xf; */
217	*hour = from_bcd(M48_ADDR[HOUR]);
218	*minute = from_bcd(M48_ADDR[MINUTE]);
219	*second = from_bcd(M48_ADDR[SECOND] & 0x7f);
220
221	M48_ADDR[CONTROL] &= ~0x40; /* Clear READ bit */
222
223	SYS_TOD_PROTECT();
224
225	return 0;
226	}
227
228	int m48_tod_get_second(void)
229	{
230	return from_bcd(M48_ADDR[SECOND] & 0x7f);
231	}
232
233	/*
234	* Watchdog function
235	*
236	* If usec is 0, the watchdog timer is disarmed.
237	*
238	* If usec is non-zero, the watchdog timer is armed (or re-armed) for
239	* approximately usec microseconds (if the exact requested usec is
240	* not supported by the chip, the next higher available value is used).
241	*
242	* Minimum watchdog timeout = 62500 usec
243	* Maximum watchdog timeout = 124 sec (124000000 usec)
244	*/
245
246	void m48_watchdog_arm(int usec)
247	{
248	int mpy, res;
249
250	SYS_TOD_UNPROTECT();
251
252	if (usec == 0) {
253	res = 0;
254	mpy = 0;
255	} else if (usec < 2000000) { /* Resolution: 1/16s if below 2s */
256	res = 0;
257	mpy = (usec + 62499) / 62500;
258	} else if (usec < 8000000) { /* Resolution: 1/4s if below 8s */
259	res = 1;
260	mpy = (usec + 249999) / 250000;
261	} else if (usec < 32000000) { /* Resolution: 1s if below 32s */
262	res = 2;
263	mpy = (usec + 999999) / 1000000;
264	} else { /* Resolution: 4s up to 124s */
265	res = 3;
266	mpy = (usec + 3999999) / 4000000;
267	if (mpy > 31)
268	mpy = 31;
269	}
270
271	M48_ADDR[WATCH] = (0x80 \| /* Steer to RST signal (IRQ = N/C) */
272	mpy << 2 \|
273	res);
274
275	SYS_TOD_PROTECT();
276	}
277
278	/*
279	* U-Boot RTC support.
280	*/
b73a19e1	281	int
f9087a32 WD	282	rtc_get( struct rtc_time *tmp )
	283	{
	284	m48_tod_get(&tmp->tm_year,
	285	&tmp->tm_mon,
	286	&tmp->tm_mday,
	287	&tmp->tm_hour,
	288	&tmp->tm_min,
	289	&tmp->tm_sec);
	290	tmp->tm_yday = 0;
	291	tmp->tm_isdst= 0;
	292
	293	#ifdef RTC_DEBUG
	294	printf( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
	295	tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
	296	tmp->tm_hour, tmp->tm_min, tmp->tm_sec );
	297	#endif
b73a19e1 YT	298
b73a19e1 YT	299	return 0;
f9087a32 WD	300	}
f9087a32 WD	301
d1e23194	302	int rtc_set( struct rtc_time *tmp )
f9087a32 WD	303	{
	304	m48_tod_set(tmp->tm_year, /* 1980-2079 */
	305	tmp->tm_mon, /* 01-12 */
	306	tmp->tm_mday, /* 01-31 */
	307	tmp->tm_hour, /* 00-23 */
	308	tmp->tm_min, /* 00-59 */
	309	tmp->tm_sec); /* 00-59 */
	310
	311	#ifdef RTC_DEBUG
	312	printf( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
	313	tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
	314	tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
	315	#endif
	316
d1e23194	317	return 0;
f9087a32 WD	318	}
	319
	320	void
	321	rtc_reset (void)
	322	{
	323	m48_tod_init();
	324	}