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git.ipfire.org Git - people/ms/u-boot.git/blob - drivers/rtc/m48t35ax.c
3 * Erik Theisen, Wave 7 Optics, etheisen@mindspring.com.
5 * See file CREDITS for list of people who contributed to this
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.
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.
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,
25 * Date & Time support for ST Electronics M48T35Ax RTC
36 #if defined(CONFIG_RTC_M48T35A) && defined(CONFIG_CMD_DATE)
38 static uchar
rtc_read (uchar reg
);
39 static void rtc_write (uchar reg
, uchar val
);
40 static uchar
bin2bcd (unsigned int n
);
41 static unsigned bcd2bin(uchar c
);
43 /* ------------------------------------------------------------------------- */
45 int rtc_get (struct rtc_time
*tmp
)
47 uchar sec
, min
, hour
, cent_day
, date
, month
, year
;
48 uchar ccr
; /* Clock control register */
50 /* Lock RTC for read using clock control register */
57 hour
= rtc_read (0x3);
58 cent_day
= rtc_read (0x4);
59 date
= rtc_read (0x5);
60 month
= rtc_read (0x6);
61 year
= rtc_read (0x7);
68 debug ( "Get RTC year: %02x month: %02x date: %02x cent_day: %02x "
69 "hr: %02x min: %02x sec: %02x\n",
70 year
, month
, date
, cent_day
,
73 tmp
->tm_sec
= bcd2bin (sec
& 0x7F);
74 tmp
->tm_min
= bcd2bin (min
& 0x7F);
75 tmp
->tm_hour
= bcd2bin (hour
& 0x3F);
76 tmp
->tm_mday
= bcd2bin (date
& 0x3F);
77 tmp
->tm_mon
= bcd2bin (month
& 0x1F);
78 tmp
->tm_year
= bcd2bin (year
) + ((cent_day
& 0x10) ? 2000 : 1900);
79 tmp
->tm_wday
= bcd2bin (cent_day
& 0x07);
83 debug ( "Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
84 tmp
->tm_year
, tmp
->tm_mon
, tmp
->tm_mday
, tmp
->tm_wday
,
85 tmp
->tm_hour
, tmp
->tm_min
, tmp
->tm_sec
);
90 void rtc_set (struct rtc_time
*tmp
)
92 uchar ccr
; /* Clock control register */
95 debug ( "Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
96 tmp
->tm_year
, tmp
->tm_mon
, tmp
->tm_mday
, tmp
->tm_wday
,
97 tmp
->tm_hour
, tmp
->tm_min
, tmp
->tm_sec
);
99 /* Lock RTC for write using clock control register */
104 rtc_write (0x07, bin2bcd(tmp
->tm_year
% 100));
105 rtc_write (0x06, bin2bcd(tmp
->tm_mon
));
106 rtc_write (0x05, bin2bcd(tmp
->tm_mday
));
108 century
= ((tmp
->tm_year
>= 2000) ? 0x10 : 0) | 0x20;
109 rtc_write (0x04, bin2bcd(tmp
->tm_wday
) | century
);
111 rtc_write (0x03, bin2bcd(tmp
->tm_hour
));
112 rtc_write (0x02, bin2bcd(tmp
->tm_min
));
113 rtc_write (0x01, bin2bcd(tmp
->tm_sec
));
121 void rtc_reset (void)
125 /* Clear all clock control registers */
126 rtc_write (0x0, 0x80); /* No Read Lock or calibration */
129 val
= rtc_read (0x1);
133 /* Enable century / disable frequency test */
134 val
= rtc_read (0x4);
135 val
= (val
& 0xBF) | 0x20;
138 /* Clear write lock */
142 /* ------------------------------------------------------------------------- */
144 static uchar
rtc_read (uchar reg
)
147 val
= *(unsigned char *)
148 ((CFG_NVRAM_BASE_ADDR
+ CFG_NVRAM_SIZE
- 8) + reg
);
152 static void rtc_write (uchar reg
, uchar val
)
155 ((CFG_NVRAM_BASE_ADDR
+ CFG_NVRAM_SIZE
- 8) + reg
) = val
;
158 static unsigned bcd2bin (uchar n
)
160 return ((((n
>> 4) & 0x0F) * 10) + (n
& 0x0F));
163 static unsigned char bin2bcd (unsigned int n
)
165 return (((n
/ 10) << 4) | (n
% 10));