diff options
Diffstat (limited to 'drivers/rtc/rtc4543.c')
| -rw-r--r-- | drivers/rtc/rtc4543.c | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/drivers/rtc/rtc4543.c b/drivers/rtc/rtc4543.c new file mode 100644 index 0000000..242d9bc --- /dev/null +++ b/drivers/rtc/rtc4543.c @@ -0,0 +1,118 @@ +/* + * (C) Copyright 2008, 2009 + * Andreas Pfefferle, DENX Software Engineering, ap@denx.de. + * + * 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 + */ + +#include <asm/io.h> +#include <common.h> +#include <command.h> +#include <config.h> +#include <bcd.h> +#include <rtc.h> +#include <tws.h> + +#if defined(CONFIG_CMD_DATE) + +/* + * Note: The acrobatics below is due to the hideously ingenius idea of + * the chip designers. As the chip does not allow register + * addressing, all values need to be read and written in one go. Sure + * enough, the 'wday' field (0-6) is transferred using the economic + * number of 4 bits right in the middle of the packet..... + */ + +int rtc_get(struct rtc_time *tm) +{ + int rel = 0; + uchar buffer[7]; + + memset(buffer, 0, 7); + + /* Read 52 bits into our buffer */ + tws_read(buffer, 52); + + tm->tm_sec = BCD2BIN( buffer[0] & 0x7F); + tm->tm_min = BCD2BIN( buffer[1] & 0x7F); + tm->tm_hour = BCD2BIN( buffer[2] & 0x3F); + tm->tm_wday = BCD2BIN( buffer[3] & 0x07); + tm->tm_mday = BCD2BIN((buffer[3] & 0xF0) >> 4 | (buffer[4] & 0x0F) << 4); + tm->tm_mon = BCD2BIN((buffer[4] & 0x30) >> 4 | (buffer[5] & 0x0F) << 4); + tm->tm_year = BCD2BIN((buffer[5] & 0xF0) >> 4 | (buffer[6] & 0x0F) << 4) + 2000; + tm->tm_yday = 0; + tm->tm_isdst = 0; + + if (tm->tm_sec & 0x80) { + puts("### Warning: RTC Low Voltage - date/time not reliable\n"); + rel = -1; + } + + debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", + tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday, + tm->tm_hour, tm->tm_min, tm->tm_sec); + + return rel; +} + +int rtc_set(struct rtc_time *tm) +{ + uchar buffer[7]; + uchar tmp; + + debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", + tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday, + tm->tm_hour, tm->tm_min, tm->tm_sec); + + memset(buffer, 0, 7); + buffer[0] = BIN2BCD(tm->tm_sec); + buffer[1] = BIN2BCD(tm->tm_min); + buffer[2] = BIN2BCD(tm->tm_hour); + buffer[3] = BIN2BCD(tm->tm_wday); + tmp = BIN2BCD(tm->tm_mday); + buffer[3] |= (tmp & 0x0F) << 4; + buffer[4] = (tmp & 0xF0) >> 4; + tmp = BIN2BCD(tm->tm_mon); + buffer[4] |= (tmp & 0x0F) << 4; + buffer[5] = (tmp & 0xF0) >> 4; + tmp = BIN2BCD(tm->tm_year % 100); + buffer[5] |= (tmp & 0x0F) << 4; + buffer[6] = (tmp & 0xF0) >> 4; + + /* Write the resulting 52 bits to device */ + tws_write(buffer, 52); + + return 0; +} + +void rtc_reset(void) +{ + struct rtc_time tmp; + + tmp.tm_sec = 0; + tmp.tm_min = 0; + tmp.tm_hour = 0; + tmp.tm_wday = 4; + tmp.tm_mday = 1; + tmp.tm_mon = 1; + tmp.tm_year = 2000; + rtc_set(&tmp); +} + +#endif |