MINI2440: Add a command to re-init CFI NOR
[u-boot-openmoko/mini2440.git] / drivers / rtc / ds1307.c
blobb20f193b418c05a8e4e82da1540c415aed583676
1 /*
2 * (C) Copyright 2001, 2002, 2003
3 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4 * Keith Outwater, keith_outwater@mvis.com`
5 * Steven Scholz, steven.scholz@imc-berlin.de
7 * See file CREDITS for list of people who contributed to this
8 * project.
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of
13 * the License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23 * MA 02111-1307 USA
27 * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
28 * DS1307 and DS1338 Real Time Clock (RTC).
30 * based on ds1337.c
33 #include <common.h>
34 #include <command.h>
35 #include <rtc.h>
36 #include <i2c.h>
38 #if (defined(CONFIG_RTC_DS1307) || defined(CONFIG_RTC_DS1338) ) && \
39 defined(CONFIG_CMD_DATE)
41 /*---------------------------------------------------------------------*/
42 #undef DEBUG_RTC
44 #ifdef DEBUG_RTC
45 #define DEBUGR(fmt,args...) printf(fmt ,##args)
46 #else
47 #define DEBUGR(fmt,args...)
48 #endif
49 /*---------------------------------------------------------------------*/
51 #ifndef CFG_I2C_RTC_ADDR
52 # define CFG_I2C_RTC_ADDR 0x68
53 #endif
55 #if defined(CONFIG_RTC_DS1307) && (CFG_I2C_SPEED > 100000)
56 # error The DS1307 is specified only up to 100kHz!
57 #endif
60 * RTC register addresses
62 #define RTC_SEC_REG_ADDR 0x00
63 #define RTC_MIN_REG_ADDR 0x01
64 #define RTC_HR_REG_ADDR 0x02
65 #define RTC_DAY_REG_ADDR 0x03
66 #define RTC_DATE_REG_ADDR 0x04
67 #define RTC_MON_REG_ADDR 0x05
68 #define RTC_YR_REG_ADDR 0x06
69 #define RTC_CTL_REG_ADDR 0x07
71 #define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */
73 #define RTC_CTL_BIT_RS0 0x01 /* Rate select 0 */
74 #define RTC_CTL_BIT_RS1 0x02 /* Rate select 1 */
75 #define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */
76 #define RTC_CTL_BIT_OUT 0x80 /* Output Control */
78 static uchar rtc_read (uchar reg);
79 static void rtc_write (uchar reg, uchar val);
80 static uchar bin2bcd (unsigned int n);
81 static unsigned bcd2bin (uchar c);
84 * Get the current time from the RTC
86 int rtc_get (struct rtc_time *tmp)
88 int rel = 0;
89 uchar sec, min, hour, mday, wday, mon, year;
91 sec = rtc_read (RTC_SEC_REG_ADDR);
92 min = rtc_read (RTC_MIN_REG_ADDR);
93 hour = rtc_read (RTC_HR_REG_ADDR);
94 wday = rtc_read (RTC_DAY_REG_ADDR);
95 mday = rtc_read (RTC_DATE_REG_ADDR);
96 mon = rtc_read (RTC_MON_REG_ADDR);
97 year = rtc_read (RTC_YR_REG_ADDR);
99 DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
100 "hr: %02x min: %02x sec: %02x\n",
101 year, mon, mday, wday, hour, min, sec);
103 if (sec & RTC_SEC_BIT_CH) {
104 printf ("### Warning: RTC oscillator has stopped\n");
105 /* clear the CH flag */
106 rtc_write (RTC_SEC_REG_ADDR,
107 rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH);
108 rel = -1;
111 tmp->tm_sec = bcd2bin (sec & 0x7F);
112 tmp->tm_min = bcd2bin (min & 0x7F);
113 tmp->tm_hour = bcd2bin (hour & 0x3F);
114 tmp->tm_mday = bcd2bin (mday & 0x3F);
115 tmp->tm_mon = bcd2bin (mon & 0x1F);
116 tmp->tm_year = bcd2bin (year) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
117 tmp->tm_wday = bcd2bin ((wday - 1) & 0x07);
118 tmp->tm_yday = 0;
119 tmp->tm_isdst= 0;
121 DEBUGR ("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
122 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
123 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
125 return rel;
130 * Set the RTC
132 void rtc_set (struct rtc_time *tmp)
134 DEBUGR ("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
135 tmp->tm_year, tmp->tm_mon, tmp->tm_mday, tmp->tm_wday,
136 tmp->tm_hour, tmp->tm_min, tmp->tm_sec);
138 if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
139 printf("WARNING: year should be between 1970 and 2069!\n");
141 rtc_write (RTC_YR_REG_ADDR, bin2bcd (tmp->tm_year % 100));
142 rtc_write (RTC_MON_REG_ADDR, bin2bcd (tmp->tm_mon));
143 rtc_write (RTC_DAY_REG_ADDR, bin2bcd (tmp->tm_wday + 1));
144 rtc_write (RTC_DATE_REG_ADDR, bin2bcd (tmp->tm_mday));
145 rtc_write (RTC_HR_REG_ADDR, bin2bcd (tmp->tm_hour));
146 rtc_write (RTC_MIN_REG_ADDR, bin2bcd (tmp->tm_min));
147 rtc_write (RTC_SEC_REG_ADDR, bin2bcd (tmp->tm_sec));
152 * Reset the RTC. We setting the date back to 1970-01-01.
153 * We also enable the oscillator output on the SQW/OUT pin and program
154 * it for 32,768 Hz output. Note that according to the datasheet, turning
155 * on the square wave output increases the current drain on the backup
156 * battery to something between 480nA and 800nA.
158 void rtc_reset (void)
160 struct rtc_time tmp;
162 rtc_write (RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */
163 rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0);
165 tmp.tm_year = 1970;
166 tmp.tm_mon = 1;
167 tmp.tm_mday= 1;
168 tmp.tm_hour = 0;
169 tmp.tm_min = 0;
170 tmp.tm_sec = 0;
172 rtc_set(&tmp);
174 printf ( "RTC: %4d-%02d-%02d %2d:%02d:%02d UTC\n",
175 tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
176 tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
178 return;
183 * Helper functions
186 static
187 uchar rtc_read (uchar reg)
189 return (i2c_reg_read (CFG_I2C_RTC_ADDR, reg));
193 static void rtc_write (uchar reg, uchar val)
195 i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val);
198 static unsigned bcd2bin (uchar n)
200 return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
203 static unsigned char bin2bcd (unsigned int n)
205 return (((n / 10) << 4) | (n % 10));
208 #endif