--- /dev/null
+/*
+ * 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.
+ */
+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();
+}
+
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