/* * 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 "mousse.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. */voidrtc_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}voidrtc_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}voidrtc_reset (void){  m48_tod_init();}