diff options
Diffstat (limited to 'drivers/rtc/isl1208.c')
| -rw-r--r-- | drivers/rtc/isl1208.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/rtc/isl1208.c b/drivers/rtc/isl1208.c new file mode 100644 index 0000000..3d46fd0 --- /dev/null +++ b/drivers/rtc/isl1208.c @@ -0,0 +1,170 @@ +/* + * (C) Copyright 2008 + * Tor Krill, Excito Elektronik i Skåne , tor@excito.com + * + * Modelled after the ds1337 driver + * + * 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 (no alarms) for Intersil + * ISL1208 Real Time Clock (RTC). + */ + +#include <common.h> +#include <command.h> +#include <rtc.h> +#include <i2c.h> + +/*---------------------------------------------------------------------*/ +#ifdef DEBUG_RTC +#define DEBUGR(fmt,args...) printf(fmt ,##args) +#else +#define DEBUGR(fmt,args...) +#endif +/*---------------------------------------------------------------------*/ + +/* + * RTC register addresses + */ + +#define RTC_SEC_REG_ADDR 0x0 +#define RTC_MIN_REG_ADDR 0x1 +#define RTC_HR_REG_ADDR 0x2 +#define RTC_DATE_REG_ADDR 0x3 +#define RTC_MON_REG_ADDR 0x4 +#define RTC_YR_REG_ADDR 0x5 +#define RTC_DAY_REG_ADDR 0x6 +#define RTC_STAT_REG_ADDR 0x7 +/* + * RTC control register bits + */ + +/* + * RTC status register bits + */ +#define RTC_STAT_BIT_ARST 0x80 /* AUTO RESET ENABLE BIT */ +#define RTC_STAT_BIT_XTOSCB 0x40 /* CRYSTAL OSCILLATOR ENABLE BIT */ +#define RTC_STAT_BIT_WRTC 0x10 /* WRITE RTC ENABLE BIT */ +#define RTC_STAT_BIT_ALM 0x04 /* ALARM BIT */ +#define RTC_STAT_BIT_BAT 0x02 /* BATTERY BIT */ +#define RTC_STAT_BIT_RTCF 0x01 /* REAL TIME CLOCK FAIL BIT */ + +static uchar rtc_read (uchar reg); +static void rtc_write (uchar reg, uchar val); +static uchar bin2bcd (unsigned int n); +static unsigned bcd2bin (uchar c); + +/* + * Get the current time from the RTC + */ + +int rtc_get (struct rtc_time *tmp) +{ + int rel = 0; + uchar sec, min, hour, mday, wday, mon, year, status; + + status = rtc_read (RTC_STAT_REG_ADDR); + sec = rtc_read (RTC_SEC_REG_ADDR); + min = rtc_read (RTC_MIN_REG_ADDR); + hour = rtc_read (RTC_HR_REG_ADDR); + wday = rtc_read (RTC_DAY_REG_ADDR); + mday = rtc_read (RTC_DATE_REG_ADDR); + mon = rtc_read (RTC_MON_REG_ADDR); + year = rtc_read (RTC_YR_REG_ADDR); + + DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " + "hr: %02x min: %02x sec: %02x status: %02x\n", + year, mon, mday, wday, hour, min, sec, status); + + if (status & RTC_STAT_BIT_RTCF) { + printf ("### Warning: RTC oscillator has stopped\n"); + rtc_write(RTC_STAT_REG_ADDR, + rtc_read(RTC_STAT_REG_ADDR) &~ (RTC_STAT_BIT_BAT|RTC_STAT_BIT_RTCF)); + rel = -1; + } + + 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_year = bcd2bin (year)+2000; + tmp->tm_wday = bcd2bin (wday & 0x07); + tmp->tm_yday = 0; + tmp->tm_isdst= 0; + + DEBUGR ("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); + + return rel; +} + +/* + * Set the RTC + */ +void rtc_set (struct rtc_time *tmp) +{ + DEBUGR ("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); + + /* enable write */ + rtc_write(RTC_STAT_REG_ADDR, + rtc_read(RTC_STAT_REG_ADDR) | RTC_STAT_BIT_WRTC); + + rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100)); + rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon)); + rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday)); + rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday)); + rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour) | 0x80 ); /* 24h clock */ + rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min)); + rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec)); + + /* disable write */ + rtc_write(RTC_STAT_REG_ADDR, + rtc_read(RTC_STAT_REG_ADDR) & ~RTC_STAT_BIT_WRTC); +} + +void rtc_reset (void) +{ +} + +/* + * Helper functions + */ + +static uchar rtc_read (uchar reg) +{ + return (i2c_reg_read (CFG_I2C_RTC_ADDR, reg)); +} + +static void rtc_write (uchar reg, uchar val) +{ + i2c_reg_write (CFG_I2C_RTC_ADDR, reg, 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)); +} |