diff options
Diffstat (limited to 'drivers/rtc/ds164x.c')
| -rw-r--r-- | drivers/rtc/ds164x.c | 200 |
1 files changed, 200 insertions, 0 deletions
diff --git a/drivers/rtc/ds164x.c b/drivers/rtc/ds164x.c new file mode 100644 index 00000000000..bff22b9a058 --- /dev/null +++ b/drivers/rtc/ds164x.c @@ -0,0 +1,200 @@ +/* + * (C) Copyright 2002 + * ARIO Data Networks, Inc. dchiu@ariodata.com + * + * modified for DS164x: + * The LEOX team <team@leox.org>, http://www.leox.org + * + * Based on MontaVista DS1743 code and U-Boot mc146818 code + * + * 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 + */ + +/* + * Date & Time support for the DS164x RTC + */ + +/* #define RTC_DEBUG */ + +#include <common.h> +#include <command.h> +#include <rtc.h> + + +#if defined(CONFIG_RTC_DS164x) && defined(CONFIG_CMD_DATE) + +static uchar rtc_read(unsigned int addr ); +static void rtc_write(unsigned int addr, uchar val); +static uchar bin2bcd(unsigned int n); +static unsigned bcd2bin(uchar c); + +#define RTC_EPOCH 2000 /* century */ + +/* + * DS164x registers layout + */ +#define RTC_BASE ( CFG_NVRAM_BASE_ADDR + CFG_NVRAM_SIZE ) + +#define RTC_YEAR ( RTC_BASE + 0x07 ) +#define RTC_MONTH ( RTC_BASE + 0x06 ) +#define RTC_DAY_OF_MONTH ( RTC_BASE + 0x05 ) +#define RTC_DAY_OF_WEEK ( RTC_BASE + 0x04 ) +#define RTC_HOURS ( RTC_BASE + 0x03 ) +#define RTC_MINUTES ( RTC_BASE + 0x02 ) +#define RTC_SECONDS ( RTC_BASE + 0x01 ) +#define RTC_CONTROL ( RTC_BASE + 0x00 ) + +#define RTC_CONTROLA RTC_CONTROL /* W=bit6, R=bit5 */ +#define RTC_CA_WRITE 0x80 +#define RTC_CA_READ 0x40 +#define RTC_CONTROLB RTC_SECONDS /* OSC=bit7 */ +#define RTC_CB_OSC_DISABLE 0x80 +#define RTC_CONTROLC RTC_DAY_OF_WEEK /* FT=bit6 */ +#define RTC_CC_FREQ_TEST 0x40 + +/* ------------------------------------------------------------------------- */ + +void rtc_get( struct rtc_time *tmp ) +{ + uchar sec, min, hour; + uchar mday, wday, mon, year; + + uchar reg_a; + + reg_a = rtc_read( RTC_CONTROLA ); + /* lock clock registers for read */ + rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ )); + + sec = rtc_read( RTC_SECONDS ); + min = rtc_read( RTC_MINUTES ); + hour = rtc_read( RTC_HOURS ); + mday = rtc_read( RTC_DAY_OF_MONTH ); + wday = rtc_read( RTC_DAY_OF_WEEK ); + mon = rtc_read( RTC_MONTH ); + year = rtc_read( RTC_YEAR ); + + /* unlock clock registers after read */ + rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ )); + +#ifdef RTC_DEBUG + printf( "Get RTC year: %02x mon: %02x mday: %02x wday: %02x " + "hr: %02x min: %02x sec: %02x\n", + year, mon, mday, wday, + hour, min, sec ); +#endif + tmp->tm_sec = bcd2bin( sec & 0x7F ); + tmp->tm_min = bcd2bin( min & 0x7F ); + tmp->tm_hour = bcd2bin( hour & 0x3F ); + tmp->tm_mday = bcd2bin( mday & 0x3F ); + tmp->tm_mon = bcd2bin( mon & 0x1F ); + tmp->tm_wday = bcd2bin( wday & 0x07 ); + + /* glue year in century (2000) */ + tmp->tm_year = bcd2bin( year ) + RTC_EPOCH; + + 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 ) +{ + uchar reg_a; + +#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 + /* lock clock registers for write */ + reg_a = rtc_read( RTC_CONTROLA ); + rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE )); + + rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon )); + + rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday )); + rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday )); + rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour )); + rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min )); + rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec )); + + /* break year in century */ + rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 )); + + /* unlock clock registers after read */ + rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_WRITE )); +} + +void rtc_reset (void) +{ + uchar reg_a, reg_b; + + reg_a = rtc_read( RTC_CONTROLA ); + reg_b = rtc_read( RTC_CONTROLB ); + + if ( reg_b & RTC_CB_OSC_DISABLE ) + { + printf( "real-time-clock was stopped. Now starting...\n" ); + reg_a |= RTC_CA_WRITE; + reg_b &= ~RTC_CB_OSC_DISABLE; + + rtc_write( RTC_CONTROLA, reg_a ); + rtc_write( RTC_CONTROLB, reg_b ); + } + + /* make sure read/write clock register bits are cleared */ + reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ ); + rtc_write( RTC_CONTROLA, reg_a ); +} + +/* ------------------------------------------------------------------------- */ + +static uchar rtc_read( unsigned int addr ) +{ + uchar val = *(volatile unsigned char*)(addr); + +#ifdef RTC_DEBUG + printf( "rtc_read: %x:%x\n", addr, val ); +#endif + return( val ); +} + +static void rtc_write( unsigned int addr, uchar val ) +{ +#ifdef RTC_DEBUG + printf( "rtc_write: %x:%x\n", addr, val ); +#endif + *(volatile unsigned char*)(addr) = val; +} + +static unsigned bcd2bin (uchar n) +{ + return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F)); +} + +static unsigned char bin2bcd (unsigned int n) +{ + return (((n / 10) << 4) | (n % 10)); +} + +#endif |