1 /* 2 * Copyright 2010 Freescale Semiconductor, Inc. 3 * 4 * Author: Priyanka Jain <Priyanka.Jain@freescale.com> 5 * 6 * See file CREDITS for list of people who contributed to this 7 * project. 8 * 9 * This program is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU General Public License as 11 * published by the Free Software Foundation; either version 2 of 12 * the License, or (at your option) any later version. 13 * 14 * This program is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.See the 17 * GNU General Public License for more details. 18 * 19 * You should have received a copy of the GNU General Public License 20 * along with this program; if not, write to the Free Software 21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 22 * MA 02111-1307 USA 23 */ 24 25 /* 26 * This file provides Date & Time support (no alarms) for PT7C4338 chip. 27 * 28 * This file is based on drivers/rtc/ds1337.c 29 * 30 * PT7C4338 chip is manufactured by Pericom Technology Inc. 31 * It is a serial real-time clock which provides 32 * 1)Low-power clock/calendar. 33 * 2)Programmable square-wave output. 34 * It has 56 bytes of nonvolatile RAM. 35 */ 36 37 #include <common.h> 38 #include <command.h> 39 #include <rtc.h> 40 #include <i2c.h> 41 42 /* RTC register addresses */ 43 #define RTC_SEC_REG_ADDR 0x0 44 #define RTC_MIN_REG_ADDR 0x1 45 #define RTC_HR_REG_ADDR 0x2 46 #define RTC_DAY_REG_ADDR 0x3 47 #define RTC_DATE_REG_ADDR 0x4 48 #define RTC_MON_REG_ADDR 0x5 49 #define RTC_YR_REG_ADDR 0x6 50 #define RTC_CTL_STAT_REG_ADDR 0x7 51 52 /* RTC second register address bit */ 53 #define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */ 54 55 /* RTC control and status register bits */ 56 #define RTC_CTL_STAT_BIT_RS0 0x1 /* Rate select 0 */ 57 #define RTC_CTL_STAT_BIT_RS1 0x2 /* Rate select 1 */ 58 #define RTC_CTL_STAT_BIT_SQWE 0x10 /* Square Wave Enable */ 59 #define RTC_CTL_STAT_BIT_OSF 0x20 /* Oscillator Stop Flag */ 60 #define RTC_CTL_STAT_BIT_OUT 0x80 /* Output Level Control */ 61 62 /* RTC reset value */ 63 #define RTC_PT7C4338_RESET_VAL \ 64 (RTC_CTL_STAT_BIT_RS0 | RTC_CTL_STAT_BIT_RS1 | RTC_CTL_STAT_BIT_OUT) 65 66 /****** Helper functions ****************************************/ 67 static u8 rtc_read(u8 reg) 68 { 69 return i2c_reg_read(CONFIG_SYS_I2C_RTC_ADDR, reg); 70 } 71 72 static void rtc_write(u8 reg, u8 val) 73 { 74 i2c_reg_write(CONFIG_SYS_I2C_RTC_ADDR, reg, val); 75 } 76 /****************************************************************/ 77 78 /* Get the current time from the RTC */ 79 int rtc_get(struct rtc_time *tmp) 80 { 81 int ret = 0; 82 u8 sec, min, hour, mday, wday, mon, year, ctl_stat; 83 84 ctl_stat = rtc_read(RTC_CTL_STAT_REG_ADDR); 85 sec = rtc_read(RTC_SEC_REG_ADDR); 86 min = rtc_read(RTC_MIN_REG_ADDR); 87 hour = rtc_read(RTC_HR_REG_ADDR); 88 wday = rtc_read(RTC_DAY_REG_ADDR); 89 mday = rtc_read(RTC_DATE_REG_ADDR); 90 mon = rtc_read(RTC_MON_REG_ADDR); 91 year = rtc_read(RTC_YR_REG_ADDR); 92 debug("Get RTC year: %02x mon: %02x mday: %02x wday: %02x " 93 "hr: %02x min: %02x sec: %02x control_status: %02x\n", 94 year, mon, mday, wday, hour, min, sec, ctl_stat); 95 96 if (ctl_stat & RTC_CTL_STAT_BIT_OSF) { 97 printf("### Warning: RTC oscillator has stopped\n"); 98 /* clear the OSF flag */ 99 rtc_write(RTC_CTL_STAT_REG_ADDR, 100 rtc_read(RTC_CTL_STAT_REG_ADDR)\ 101 & ~RTC_CTL_STAT_BIT_OSF); 102 ret = -1; 103 } 104 105 tmp->tm_sec = bcd2bin(sec & 0x7F); 106 tmp->tm_min = bcd2bin(min & 0x7F); 107 tmp->tm_hour = bcd2bin(hour & 0x3F); 108 tmp->tm_mday = bcd2bin(mday & 0x3F); 109 tmp->tm_mon = bcd2bin(mon & 0x1F); 110 tmp->tm_year = bcd2bin(year) + 2000; 111 tmp->tm_wday = bcd2bin((wday - 1) & 0x07); 112 tmp->tm_yday = 0; 113 tmp->tm_isdst = 0; 114 debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 115 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 116 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 117 118 return ret; 119 } 120 121 /* Set the RTC */ 122 int rtc_set(struct rtc_time *tmp) 123 { 124 debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n", 125 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday, 126 tmp->tm_hour, tmp->tm_min, tmp->tm_sec); 127 128 rtc_write(RTC_YR_REG_ADDR, bin2bcd(tmp->tm_year % 100)); 129 rtc_write(RTC_MON_REG_ADDR, bin2bcd(tmp->tm_mon)); 130 rtc_write(RTC_DAY_REG_ADDR, bin2bcd(tmp->tm_wday + 1)); 131 rtc_write(RTC_DATE_REG_ADDR, bin2bcd(tmp->tm_mday)); 132 rtc_write(RTC_HR_REG_ADDR, bin2bcd(tmp->tm_hour)); 133 rtc_write(RTC_MIN_REG_ADDR, bin2bcd(tmp->tm_min)); 134 rtc_write(RTC_SEC_REG_ADDR, bin2bcd(tmp->tm_sec)); 135 136 return 0; 137 } 138 139 /* Reset the RTC */ 140 void rtc_reset(void) 141 { 142 rtc_write(RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */ 143 rtc_write(RTC_CTL_STAT_REG_ADDR, RTC_PT7C4338_RESET_VAL); 144 } 145