board/bmw/m48t59y.c - uboot/windcharger - Git at Google

 /*
  * SGS M48-T59Y TOD/NVRAM Driver
  *
  * (C) Copyright 2000
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  *
  * (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.
  */
 void
 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
 }

 void
 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

 }

 void
 rtc_reset (void)
 {
   m48_tod_init();
 }
	/*
	* SGS M48-T59Y TOD/NVRAM Driver
	*
	* (C) Copyright 2000
	* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
	*
	* (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.
	*/
	void
	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
	}

	void
	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

	}

	void
	rtc_reset (void)
	{
	m48_tod_init();
	}