]>
git.ipfire.org Git - people/ms/u-boot.git/blob - drivers/rtc/rtc4543.c
2 * (C) Copyright 2008, 2009
3 * Andreas Pfefferle, DENX Software Engineering, ap@denx.de.
5 * SPDX-License-Identifier: GPL-2.0+
15 #if defined(CONFIG_CMD_DATE)
18 * Note: The acrobatics below is due to the hideously ingenius idea of
19 * the chip designers. As the chip does not allow register
20 * addressing, all values need to be read and written in one go. Sure
21 * enough, the 'wday' field (0-6) is transferred using the economic
22 * number of 4 bits right in the middle of the packet.....
25 int rtc_get(struct rtc_time
*tm
)
32 /* Read 52 bits into our buffer */
35 tm
->tm_sec
= bcd2bin( buffer
[0] & 0x7F);
36 tm
->tm_min
= bcd2bin( buffer
[1] & 0x7F);
37 tm
->tm_hour
= bcd2bin( buffer
[2] & 0x3F);
38 tm
->tm_wday
= bcd2bin( buffer
[3] & 0x07);
39 tm
->tm_mday
= bcd2bin((buffer
[3] & 0xF0) >> 4 | (buffer
[4] & 0x0F) << 4);
40 tm
->tm_mon
= bcd2bin((buffer
[4] & 0x30) >> 4 | (buffer
[5] & 0x0F) << 4);
41 tm
->tm_year
= bcd2bin((buffer
[5] & 0xF0) >> 4 | (buffer
[6] & 0x0F) << 4) + 2000;
45 if (tm
->tm_sec
& 0x80) {
46 puts("### Warning: RTC Low Voltage - date/time not reliable\n");
50 debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
51 tm
->tm_year
, tm
->tm_mon
, tm
->tm_mday
, tm
->tm_wday
,
52 tm
->tm_hour
, tm
->tm_min
, tm
->tm_sec
);
57 int rtc_set(struct rtc_time
*tm
)
62 debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
63 tm
->tm_year
, tm
->tm_mon
, tm
->tm_mday
, tm
->tm_wday
,
64 tm
->tm_hour
, tm
->tm_min
, tm
->tm_sec
);
67 buffer
[0] = bin2bcd(tm
->tm_sec
);
68 buffer
[1] = bin2bcd(tm
->tm_min
);
69 buffer
[2] = bin2bcd(tm
->tm_hour
);
70 buffer
[3] = bin2bcd(tm
->tm_wday
);
71 tmp
= bin2bcd(tm
->tm_mday
);
72 buffer
[3] |= (tmp
& 0x0F) << 4;
73 buffer
[4] = (tmp
& 0xF0) >> 4;
74 tmp
= bin2bcd(tm
->tm_mon
);
75 buffer
[4] |= (tmp
& 0x0F) << 4;
76 buffer
[5] = (tmp
& 0xF0) >> 4;
77 tmp
= bin2bcd(tm
->tm_year
% 100);
78 buffer
[5] |= (tmp
& 0x0F) << 4;
79 buffer
[6] = (tmp
& 0xF0) >> 4;
81 /* Write the resulting 52 bits to device */
82 tws_write(buffer
, 52);