rtc/bf533_rtc.c

   1 /*
   2  * (C) Copyright 2001
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * See file CREDITS for list of people who contributed to this
   6  * project.
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation; either version 2 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
  21  * MA 02111-1307 USA
  22  * Real Time Clock interface of ADI21535 (Blackfin) for uCLinux
  23  *
  24  * Copyright (C) 2003 Motorola Corporation.  All rights reserved.
  25  *                              Richard Xiao (A2590C@email.mot.com)
  26  *
  27  * Copyright (C) 1996 Paul Gortmaker
  28  *
  29  *
  30  *      Based on other minimal char device drivers, like Alan's
  31  *      watchdog, Ted's random, etc. etc.
  32  *
  33  *      1.07    Paul Gortmaker.
  34  *      1.08    Miquel van Smoorenburg: disallow certain things on the
  35  *              DEC Alpha as the CMOS clock is also used for other things.
  36  *      1.09    Nikita Schmidt: epoch support and some Alpha cleanup.
  37  *      1.09a   Pete Zaitcev: Sun SPARC
  38  *      1.09b   Jeff Garzik: Modularize, init cleanup
  39  *      1.09c   Jeff Garzik: SMP cleanup
  40  *      1.10    Paul Barton-Davis: add support for async I/O
  41  *      1.10a   Andrea Arcangeli: Alpha updates
  42  *      1.10b   Andrew Morton: SMP lock fix
  43  *      1.10c   Cesar Barros: SMP locking fixes and cleanup
  44  *      1.10d   Paul Gortmaker: delete paranoia check in rtc_exit
  45  *      1.10e   LG Soft India: Register access is different in BF533.
  46  */
  47
  48 #include <common.h>
  49 #include <command.h>
  50 #include <rtc.h>
  51
  52 #if defined(CONFIG_RTC_BF533) && (CONFIG_COMMANDS & CFG_CMD_DATE)
  53
  54 #include <asm/blackfin.h>
  55 #include <asm/cpu/bf533_rtc.h>
  56
  57 void rtc_reset(void)
  58 {
  59         return;                 /* nothing to do */
  60 }
  61
  62 /* Wait for pending writes to complete */
  63 void wait_for_complete(void)
  64 {
  65         while (!(*(volatile unsigned short *) RTC_ISTAT & 0x8000)) {
  66                 printf("");
  67         }
  68         *(volatile unsigned short *) RTC_ISTAT = 0x8000;
  69 }
  70
  71 /* Enable the RTC prescaler enable register */
  72 void rtc_init()
  73 {
  74         *(volatile unsigned short *) RTC_PREN = 0x1;
  75         wait_for_complete();
  76 }
  77
  78 /* Set the time. Get the time_in_secs which is the number of seconds since Jan 1970 and set the RTC registers
  79  * based on this value.
  80  */
  81 void rtc_set (struct rtc_time *tmp)
  82 {
  83         unsigned long n_days_1970 = 0;
  84         unsigned long n_secs_rem  = 0;
  85         unsigned long n_hrs       = 0;
  86         unsigned long n_mins      = 0;
  87         unsigned long n_secs      = 0;
  88         unsigned long time_in_secs;
  89
  90         if(tmp == NULL) {
  91                 printf("Error setting the date/time \n");
  92                 return;
  93         }
  94
  95         time_in_secs = mktime(tmp->tm_year, tmp->tm_mon, tmp->tm_mday,tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
  96
  97         /* Compute no. of days since 1970 */
  98         n_days_1970 = (unsigned long) (time_in_secs / (NUM_SECS_IN_DAY));
  99
 100         /* From the remining secs, compute the hrs(0-23), mins(0-59) and secs(0-59) */
 101         n_secs_rem = (unsigned long)(time_in_secs % (NUM_SECS_IN_DAY));
 102         n_hrs   = n_secs_rem / (NUM_SECS_IN_HOUR);
 103         n_secs_rem = n_secs_rem % (NUM_SECS_IN_HOUR);
 104         n_mins = n_secs_rem / (NUM_SECS_IN_MIN);
 105         n_secs = n_secs_rem % (NUM_SECS_IN_MIN);
 106
 107         /* Store the new time in the RTC_STAT register */
 108         *(volatile unsigned long *) RTC_STAT =
 109                 ((n_days_1970 << DAY_BITS_OFF) | (n_hrs << HOUR_BITS_OFF) |
 110                 (n_mins << MIN_BITS_OFF) | (n_secs << SEC_BITS_OFF));
 111
 112         wait_for_complete();
 113 }
 114
 115 /* Read the time from the RTC_STAT. time_in_seconds is seconds since Jan 1970 */
 116 void rtc_get (struct rtc_time *tmp)
 117 {
 118         unsigned long cur_rtc_stat = 0;
 119         unsigned long time_in_sec;
 120         unsigned long tm_sec = 0, tm_min = 0, tm_hour = 0, tm_day = 0;
 121
 122         if(tmp == NULL) {
 123                 printf("Error getting the date/time \n");
 124                 return;
 125         }
 126
 127         /* Read the RTC_STAT register */
 128         cur_rtc_stat = *(volatile unsigned long *) RTC_STAT;
 129
 130         /* Get the secs (0-59), mins (0-59), hrs (0-23) and the days since Jan 1970 */
 131         tm_sec = (cur_rtc_stat >> SEC_BITS_OFF) & 0x3f;
 132         tm_min = (cur_rtc_stat >> MIN_BITS_OFF) & 0x3f;
 133         tm_hour = (cur_rtc_stat >> HOUR_BITS_OFF) & 0x1f;
 134         tm_day = (cur_rtc_stat >> DAY_BITS_OFF) & 0x7fff;
 135
 136         /* Calculate the total number of seconds since Jan 1970 */
 137         time_in_sec     =       (tm_sec) +
 138                                         MIN_TO_SECS(tm_min) +
 139                                                 HRS_TO_SECS(tm_hour) +
 140                                                         DAYS_TO_SECS(tm_day);
 141         to_tm(time_in_sec,tmp);
 142 }
 143 #endif  /* CONFIG_RTC_BF533 && CFG_CMD_DATE */