diff options
Diffstat (limited to 'drivers/rtc/m41t62.c')
| -rw-r--r-- | drivers/rtc/m41t62.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/drivers/rtc/m41t62.c b/drivers/rtc/m41t62.c new file mode 100644 index 000000000..2bdca3bdf --- /dev/null +++ b/drivers/rtc/m41t62.c @@ -0,0 +1,135 @@ +/* + * (C) Copyright 2008 + * Stefan Roese, DENX Software Engineering, sr@denx.de. + * + * based on a the Linux rtc-m41t80.c driver which is: + * Alexander Bigga <ab@mycable.de>, 2006 (c) mycable GmbH + * + * 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 STMicroelectronics M41T62 + */ + +/* #define DEBUG */ + +#include <common.h> +#include <command.h> +#include <rtc.h> +#include <i2c.h> +#include <bcd.h> + +#if defined(CONFIG_CMD_DATE) + +#define M41T62_REG_SSEC 0 +#define M41T62_REG_SEC 1 +#define M41T62_REG_MIN 2 +#define M41T62_REG_HOUR 3 +#define M41T62_REG_WDAY 4 +#define M41T62_REG_DAY 5 +#define M41T62_REG_MON 6 +#define M41T62_REG_YEAR 7 +#define M41T62_REG_ALARM_MON 0xa +#define M41T62_REG_ALARM_DAY 0xb +#define M41T62_REG_ALARM_HOUR 0xc +#define M41T62_REG_ALARM_MIN 0xd +#define M41T62_REG_ALARM_SEC 0xe +#define M41T62_REG_FLAGS 0xf + +#define M41T62_DATETIME_REG_SIZE (M41T62_REG_YEAR + 1) +#define M41T62_ALARM_REG_SIZE \ + (M41T62_REG_ALARM_SEC + 1 - M41T62_REG_ALARM_MON) + +#define M41T62_SEC_ST (1 << 7) /* ST: Stop Bit */ +#define M41T62_ALMON_AFE (1 << 7) /* AFE: AF Enable Bit */ +#define M41T62_ALMON_SQWE (1 << 6) /* SQWE: SQW Enable Bit */ +#define M41T62_ALHOUR_HT (1 << 6) /* HT: Halt Update Bit */ +#define M41T62_FLAGS_AF (1 << 6) /* AF: Alarm Flag Bit */ +#define M41T62_FLAGS_BATT_LOW (1 << 4) /* BL: Battery Low Bit */ + +#define M41T62_FEATURE_HT (1 << 0) +#define M41T62_FEATURE_BL (1 << 1) + +void rtc_get(struct rtc_time *tm) +{ + u8 buf[M41T62_DATETIME_REG_SIZE]; + + i2c_read(CFG_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE); + + debug("%s: raw read data - sec=%02x, min=%02x, hr=%02x, " + "mday=%02x, mon=%02x, year=%02x, wday=%02x, y2k=%02x\n", + __FUNCTION__, + buf[0], buf[1], buf[2], buf[3], + buf[4], buf[5], buf[6], buf[7]); + + tm->tm_sec = BCD2BIN(buf[M41T62_REG_SEC] & 0x7f); + tm->tm_min = BCD2BIN(buf[M41T62_REG_MIN] & 0x7f); + tm->tm_hour = BCD2BIN(buf[M41T62_REG_HOUR] & 0x3f); + tm->tm_mday = BCD2BIN(buf[M41T62_REG_DAY] & 0x3f); + tm->tm_wday = buf[M41T62_REG_WDAY] & 0x07; + tm->tm_mon = BCD2BIN(buf[M41T62_REG_MON] & 0x1f) - 1; + + /* assume 20YY not 19YY, and ignore the Century Bit */ + /* U-Boot needs to add 1900 here */ + tm->tm_year = BCD2BIN(buf[M41T62_REG_YEAR]) + 100 + 1900; + + debug("%s: tm is secs=%d, mins=%d, hours=%d, " + "mday=%d, mon=%d, year=%d, wday=%d\n", + __FUNCTION__, + tm->tm_sec, tm->tm_min, tm->tm_hour, + tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday); +} + +void rtc_set(struct rtc_time *tm) +{ + u8 buf[M41T62_DATETIME_REG_SIZE]; + + 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); + + i2c_read(CFG_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE); + + /* Merge time-data and register flags into buf[0..7] */ + buf[M41T62_REG_SSEC] = 0; + buf[M41T62_REG_SEC] = + BIN2BCD(tm->tm_sec) | (buf[M41T62_REG_SEC] & ~0x7f); + buf[M41T62_REG_MIN] = + BIN2BCD(tm->tm_min) | (buf[M41T62_REG_MIN] & ~0x7f); + buf[M41T62_REG_HOUR] = + BIN2BCD(tm->tm_hour) | (buf[M41T62_REG_HOUR] & ~0x3f) ; + buf[M41T62_REG_WDAY] = + (tm->tm_wday & 0x07) | (buf[M41T62_REG_WDAY] & ~0x07); + buf[M41T62_REG_DAY] = + BIN2BCD(tm->tm_mday) | (buf[M41T62_REG_DAY] & ~0x3f); + buf[M41T62_REG_MON] = + BIN2BCD(tm->tm_mon + 1) | (buf[M41T62_REG_MON] & ~0x1f); + /* assume 20YY not 19YY */ + buf[M41T62_REG_YEAR] = BIN2BCD(tm->tm_year % 100); + + if (i2c_write(CFG_I2C_RTC_ADDR, 0, 1, buf, M41T62_DATETIME_REG_SIZE)) + printf("I2C write failed in %s()\n", __func__); +} + +void rtc_reset(void) +{ + /* + * Nothing to do + */ +} + +#endif |