diff options
Diffstat (limited to 'drivers/rtc/pt7c4338.c')
| -rw-r--r-- | drivers/rtc/pt7c4338.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/drivers/rtc/pt7c4338.c b/drivers/rtc/pt7c4338.c new file mode 100644 index 0000000..26e2c1e --- /dev/null +++ b/drivers/rtc/pt7c4338.c @@ -0,0 +1,144 @@ +/* + * Copyright 2010 Freescale Semiconductor, Inc. + * + * Author: Priyanka Jain <Priyanka.Jain@freescale.com> + * + * 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 + */ + +/* + * This file provides Date & Time support (no alarms) for PT7C4338 chip. + * + * This file is based on drivers/rtc/ds1337.c + * + * PT7C4338 chip is manufactured by Pericom Technology Inc. + * It is a serial real-time clock which provides + * 1)Low-power clock/calendar. + * 2)Programmable square-wave output. + * It has 56 bytes of nonvolatile RAM. + */ + +#include <common.h> +#include <command.h> +#include <rtc.h> +#include <i2c.h> + +/* RTC register addresses */ +#define RTC_SEC_REG_ADDR 0x0 +#define RTC_MIN_REG_ADDR 0x1 +#define RTC_HR_REG_ADDR 0x2 +#define RTC_DAY_REG_ADDR 0x3 +#define RTC_DATE_REG_ADDR 0x4 +#define RTC_MON_REG_ADDR 0x5 +#define RTC_YR_REG_ADDR 0x6 +#define RTC_CTL_STAT_REG_ADDR 0x7 + +/* RTC second register address bit */ +#define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */ + +/* RTC control and status register bits */ +#define RTC_CTL_STAT_BIT_RS0 0x1 /* Rate select 0 */ +#define RTC_CTL_STAT_BIT_RS1 0x2 /* Rate select 1 */ +#define RTC_CTL_STAT_BIT_SQWE 0x10 /* Square Wave Enable */ +#define RTC_CTL_STAT_BIT_OSF 0x20 /* Oscillator Stop Flag */ +#define RTC_CTL_STAT_BIT_OUT 0x80 /* Output Level Control */ + +/* RTC reset value */ +#define RTC_PT7C4338_RESET_VAL \ + (RTC_CTL_STAT_BIT_RS0 | RTC_CTL_STAT_BIT_RS1 | RTC_CTL_STAT_BIT_OUT) + +/****** Helper functions ****************************************/ +static u8 rtc_read(u8 reg) +{ + return i2c_reg_read(CONFIG_SYS_I2C_RTC_ADDR, reg); +} + +static void rtc_write(u8 reg, u8 val) +{ + i2c_reg_write(CONFIG_SYS_I2C_RTC_ADDR, reg, val); +} +/****************************************************************/ + +/* Get the current time from the RTC */ +int rtc_get(struct rtc_time *tmp) +{ + int ret = 0; + u8 sec, min, hour, mday, wday, mon, year, ctl_stat; + + ctl_stat = rtc_read(RTC_CTL_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); + debug("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " + "hr: %02x min: %02x sec: %02x control_status: %02x\n", + year, mon, mday, wday, hour, min, sec, ctl_stat); + + if (ctl_stat & RTC_CTL_STAT_BIT_OSF) { + printf("### Warning: RTC oscillator has stopped\n"); + /* clear the OSF flag */ + rtc_write(RTC_CTL_STAT_REG_ADDR, + rtc_read(RTC_CTL_STAT_REG_ADDR)\ + & ~RTC_CTL_STAT_BIT_OSF); + ret = -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 - 1) & 0x07); + tmp->tm_yday = 0; + tmp->tm_isdst = 0; + debug("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 ret; +} + +/* Set the RTC */ +int rtc_set(struct rtc_time *tmp) +{ + debug("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); + + 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 + 1)); + rtc_write(RTC_DATE_REG_ADDR, bin2bcd(tmp->tm_mday)); + rtc_write(RTC_HR_REG_ADDR, bin2bcd(tmp->tm_hour)); + rtc_write(RTC_MIN_REG_ADDR, bin2bcd(tmp->tm_min)); + rtc_write(RTC_SEC_REG_ADDR, bin2bcd(tmp->tm_sec)); + + return 0; +} + +/* Reset the RTC */ +void rtc_reset(void) +{ + rtc_write(RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */ + rtc_write(RTC_CTL_STAT_REG_ADDR, RTC_PT7C4338_RESET_VAL); +} |