Add support for DS1374 RTC chip.

CHANGELOG

@@ -2,6 +2,8 @@
 Changes since U-Boot 1.1.4:
 ======================================================================
 
+* Add support for DS1374 RTC chip.
+
 * Apply SoC concept to arm926ejs CPUs, i.e. move the SoC specific
   timer and cpu_reset code from cpu/$(CPU) into the new
   cpu/$(CPU)/$(SOC) directories

rtc/Makefile

@@ -29,7 +29,7 @@ LIB	= librtc.a
 
 OBJS	= date.o   \
 	  bf533_rtc.o ds12887.o ds1302.o ds1306.o ds1307.o \
-	  ds1337.o ds1556.o ds164x.o ds174x.o \
+	  ds1337.o ds1374.o ds1556.o ds164x.o ds174x.o \
 	  m41t11.o max6900.o m48t35ax.o mc146818.o mk48t59.o \
 	  mpc5xxx.o mpc8xx.o pcf8563.o s3c24x0_rtc.o rs5c372.o
 

rtc/ds1374.c

@@ -0,0 +1,253 @@
+/*
+ * (C) Copyright 2001, 2002, 2003
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ * Keith Outwater, keith_outwater@mvis.com`
+ * Steven Scholz, steven.scholz@imc-berlin.de
+ *
+ * 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
+ */
+
+/*
+ * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
+ * DS1374 Real Time Clock (RTC).
+ *
+ * based on ds1337.c
+ */
+
+#include <common.h>
+#include <command.h>
+#include <rtc.h>
+#include <i2c.h>
+
+#if (defined(CONFIG_RTC_DS1374)) && (CONFIG_COMMANDS & CFG_CMD_DATE)
+
+/*---------------------------------------------------------------------*/
+#undef DEBUG_RTC
+#define DEBUG_RTC
+
+#ifdef DEBUG_RTC
+#define DEBUGR(fmt,args...) printf(fmt ,##args)
+#else
+#define DEBUGR(fmt,args...)
+#endif
+/*---------------------------------------------------------------------*/
+
+#ifndef CFG_I2C_RTC_ADDR
+# define CFG_I2C_RTC_ADDR	0x68
+#endif
+
+#if defined(CONFIG_RTC_DS1374) && (CFG_I2C_SPEED > 400000)
+# error The DS1374 is specified up to 400kHz in fast mode!
+#endif
+
+/*
+ * RTC register addresses
+ */
+#define RTC_TOD_CNT_BYTE0_ADDR		0x00 /* TimeOfDay */
+#define RTC_TOD_CNT_BYTE1_ADDR		0x01
+#define RTC_TOD_CNT_BYTE2_ADDR		0x02
+#define RTC_TOD_CNT_BYTE3_ADDR		0x03
+
+#define RTC_WD_ALM_CNT_BYTE0_ADDR	0x04
+#define RTC_WD_ALM_CNT_BYTE1_ADDR	0x05
+#define RTC_WD_ALM_CNT_BYTE2_ADDR	0x06
+
+#define RTC_CTL_ADDR			0x07 /* RTC-CoNTrol-register */
+#define RTC_SR_ADDR			0x08 /* RTC-StatusRegister */
+#define RTC_TCS_DS_ADDR			0x09 /* RTC-TrickleChargeSelect DiodeSelect-register */
+
+#define RTC_CTL_BIT_AIE			(1<<0) /* Bit 0 - Alarm Interrupt enable */
+#define RTC_CTL_BIT_RS1			(1<<1) /* Bit 1/2 - Rate Select square wave output */
+#define RTC_CTL_BIT_RS2			(1<<2) /* Bit 2/2 - Rate Select square wave output */
+#define RTC_CTL_BIT_WDSTR		(1<<3) /* Bit 3 - Watchdog Reset Steering */
+#define RTC_CTL_BIT_BBSQW		(1<<4) /* Bit 4 - Battery-Backed Square-Wave */
+#define RTC_CTL_BIT_WD_ALM		(1<<5) /* Bit 5 - Watchdoc/Alarm Counter Select */
+#define RTC_CTL_BIT_WACE		(1<<6) /* Bit 6 - Watchdog/Alarm Counter Enable WACE*/
+#define RTC_CTL_BIT_EN_OSC		(1<<7) /* Bit 7 - Enable Oscilator */
+
+#define RTC_SR_BIT_AF			0x01 /* Bit 0 = Alarm Flag */
+#define RTC_SR_BIT_OSF			0x80 /* Bit 7 - Osc Stop Flag */
+
+typedef unsigned char boolean_t;
+
+#ifndef TRUE
+#define TRUE ((boolean_t)(0==0))
+#endif
+#ifndef FALSE
+#define FALSE (!TRUE)
+#endif
+
+const char RtcTodAddr[] = {
+	RTC_TOD_CNT_BYTE0_ADDR,
+	RTC_TOD_CNT_BYTE1_ADDR,
+	RTC_TOD_CNT_BYTE2_ADDR,
+	RTC_TOD_CNT_BYTE3_ADDR
+};
+
+static uchar rtc_read (uchar reg);
+static void rtc_write (uchar reg, uchar val, boolean_t set);
+static void rtc_write_raw (uchar reg, uchar val);
+
+/*
+ * Get the current time from the RTC
+ */
+void rtc_get (struct rtc_time *tm){
+
+	unsigned long time1, time2;
+	unsigned int limit;
+	unsigned char tmp;
+	unsigned int i;
+
+	/*
+	 * Since the reads are being performed one byte at a time,
+	 * there is a chance that a carry will occur during the read. 
+	 * To detect this, 2 reads are performed and compared.
+	 */
+	limit = 10;
+	do {
+		i = 4;
+		time1 = 0;
+		while (i--) {
+			tmp = rtc_read(RtcTodAddr[i]);
+			time1 = (time1 << 8) | (tmp & 0xff);
+		}
+
+		i = 4;
+		time2 = 0;
+		while (i--) {
+			tmp = rtc_read(RtcTodAddr[i]);
+			time2 = (time2 << 8) | (tmp & 0xff);
+		}
+	} while ((time1 != time2) && limit--);
+
+	if (time1 != time2) {
+		printf("can't get consistent time from rtc chip\n");
+	}
+
+	DEBUGR ("Get RTC s since 1.1.1970: %d\n", time1);
+
+	to_tm(time1, tm); /* To Gregorian Date */
+
+	if (rtc_read(RTC_SR_ADDR) & RTC_SR_BIT_OSF)
+		printf ("### Warning: RTC oscillator has stopped\n");
+
+	DEBUGR ("Get 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);
+}
+
+/*
+ * Set the RTC
+ */
+void rtc_set (struct rtc_time *tmp){
+
+	unsigned long time;
+	unsigned i;
+
+	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);
+
+	if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
+		printf("WARNING: year should be between 1970 and 2069!\n");
+
+	time = mktime(tmp->tm_year, tmp->tm_mon,
+			tmp->tm_mday, tmp->tm_hour,
+			tmp->tm_min, tmp->tm_sec);
+
+	DEBUGR ("Set RTC s since 1.1.1970: %d (0x%02x)\n", time, time);
+
+	/* write to RTC_TOD_CNT_BYTEn_ADDR */
+	for (i = 0; i <= 3; i++) {
+		rtc_write_raw(RtcTodAddr[i], (unsigned char)(time & 0xff));
+		time = time >> 8;
+	}
+
+	/* Start clock */
+	rtc_write(RTC_CTL_ADDR, RTC_CTL_BIT_EN_OSC, FALSE);
+}
+
+/*
+ * Reset the RTC. We setting the date back to 1970-01-01.
+ * We also enable the oscillator output on the SQW/OUT pin and program
+ * it for 32,768 Hz output. Note that according to the datasheet, turning
+ * on the square wave output increases the current drain on the backup
+ * battery to something between 480nA and 800nA.
+ */
+void rtc_reset (void){
+
+	struct rtc_time tmp;
+
+	/* clear status flags */
+	rtc_write (RTC_SR_ADDR, (RTC_SR_BIT_AF|RTC_SR_BIT_OSF), FALSE); /* clearing OSF and AF */
+
+	/* Initialise DS1374 oriented to MPC8349E-ADS */
+	rtc_write (RTC_CTL_ADDR, (RTC_CTL_BIT_EN_OSC
+				 |RTC_CTL_BIT_WACE
+				 |RTC_CTL_BIT_AIE), FALSE);/* start osc, disable WACE, clear AIE
+							      - set to 0 */
+	rtc_write (RTC_CTL_ADDR, (RTC_CTL_BIT_WD_ALM
+				|RTC_CTL_BIT_WDSTR
+				|RTC_CTL_BIT_RS1
+				|RTC_CTL_BIT_RS2
+				|RTC_CTL_BIT_BBSQW), TRUE);/* disable WD/ALM, WDSTR set to INT-pin,
+							      set BBSQW and SQW to 32k
+							      - set to 1 */
+	tmp.tm_year = 1970;
+	tmp.tm_mon = 1;
+	tmp.tm_mday= 1;
+	tmp.tm_hour = 0;
+	tmp.tm_min = 0;
+	tmp.tm_sec = 0;
+
+	rtc_set(&tmp);
+
+	printf("RTC:   %4d-%02d-%02d %2d:%02d:%02d UTC\n",
+		tmp.tm_year, tmp.tm_mon, tmp.tm_mday,
+		tmp.tm_hour, tmp.tm_min, tmp.tm_sec);
+
+	rtc_write(RTC_WD_ALM_CNT_BYTE2_ADDR,0xAC, TRUE);
+	rtc_write(RTC_WD_ALM_CNT_BYTE1_ADDR,0xDE, TRUE);
+	rtc_write(RTC_WD_ALM_CNT_BYTE2_ADDR,0xAD, TRUE);
+}
+
+/*
+ * 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, boolean_t set)
+{
+	if (set == TRUE) {
+		val |= i2c_reg_read (CFG_I2C_RTC_ADDR, reg);
+		i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val);
+	} else {
+		val = i2c_reg_read (CFG_I2C_RTC_ADDR, reg) & ~val;
+		i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val);
+	}
+}
+
+static void rtc_write_raw (uchar reg, uchar val)
+{
+		i2c_reg_write (CFG_I2C_RTC_ADDR, reg, val);
+}
+#endif /* (CONFIG_RTC_DS1374) && (CFG_COMMANDS & CFG_CMD_DATE) */