--- /dev/null
+/*
+ * (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
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+/*
+ * Date & Time support (no alarms) for Dallas Semiconductor (now Maxim)
+ * DS1307 and DS1338 Real Time Clock (RTC).
+ *
+ * based on ds1337.c
+ */
+
+#include <common.h>
+#include <command.h>
+#include <rtc.h>
+#include <i2c.h>
+
+#if defined(CONFIG_CMD_DATE)
+
+/*---------------------------------------------------------------------*/
+#undef DEBUG_RTC
+
+#ifdef DEBUG_RTC
+#define DEBUGR(fmt,args...) printf(fmt ,##args)
+#else
+#define DEBUGR(fmt,args...)
+#endif
+/*---------------------------------------------------------------------*/
+
+#ifndef CONFIG_SYS_I2C_RTC_ADDR
+# define CONFIG_SYS_I2C_RTC_ADDR 0x68
+#endif
+
+#if defined(CONFIG_RTC_DS1307) && (CONFIG_SYS_I2C_SPEED > 100000)
+# error The DS1307 is specified only up to 100kHz!
+#endif
+
+/*
+ * RTC register addresses
+ */
+#define RTC_SEC_REG_ADDR 0x00
+#define RTC_MIN_REG_ADDR 0x01
+#define RTC_HR_REG_ADDR 0x02
+#define RTC_DAY_REG_ADDR 0x03
+#define RTC_DATE_REG_ADDR 0x04
+#define RTC_MON_REG_ADDR 0x05
+#define RTC_YR_REG_ADDR 0x06
+#define RTC_CTL_REG_ADDR 0x07
+
+#define RTC_SEC_BIT_CH 0x80 /* Clock Halt (in Register 0) */
+
+#define RTC_CTL_BIT_RS0 0x01 /* Rate select 0 */
+#define RTC_CTL_BIT_RS1 0x02 /* Rate select 1 */
+#define RTC_CTL_BIT_SQWE 0x10 /* Square Wave Enable */
+#define RTC_CTL_BIT_OUT 0x80 /* Output Control */
+
+static uchar rtc_read (uchar reg);
+static void rtc_write (uchar reg, uchar val);
+
+/*
+ * Get the current time from the RTC
+ */
+int rtc_get (struct rtc_time *tmp)
+{
+ int rel = 0;
+ uchar sec, min, hour, mday, wday, mon, year;
+
+ 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);
+
+ DEBUGR ("Get RTC year: %02x mon: %02x mday: %02x wday: %02x "
+ "hr: %02x min: %02x sec: %02x\n",
+ year, mon, mday, wday, hour, min, sec);
+
+ if (sec & RTC_SEC_BIT_CH) {
+ printf ("### Warning: RTC oscillator has stopped\n");
+ /* clear the CH flag */
+ rtc_write (RTC_SEC_REG_ADDR,
+ rtc_read (RTC_SEC_REG_ADDR) & ~RTC_SEC_BIT_CH);
+ rel = -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) + ( bcd2bin (year) >= 70 ? 1900 : 2000);
+ tmp->tm_wday = bcd2bin ((wday - 1) & 0x07);
+ tmp->tm_yday = 0;
+ tmp->tm_isdst= 0;
+
+ DEBUGR ("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 rel;
+}
+
+
+/*
+ * Set the RTC
+ */
+int rtc_set (struct rtc_time *tmp)
+{
+ 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");
+
+ 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. 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;
+
+ rtc_write (RTC_SEC_REG_ADDR, 0x00); /* clearing Clock Halt */
+ rtc_write (RTC_CTL_REG_ADDR, RTC_CTL_BIT_SQWE | RTC_CTL_BIT_RS1 | RTC_CTL_BIT_RS0);
+
+ 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);
+
+ return;
+}
+
+
+/*
+ * Helper functions
+ */
+
+static
+uchar rtc_read (uchar reg)
+{
+ return (i2c_reg_read (CONFIG_SYS_I2C_RTC_ADDR, reg));
+}
+
+
+static void rtc_write (uchar reg, uchar val)
+{
+ i2c_reg_write (CONFIG_SYS_I2C_RTC_ADDR, reg, val);
+}
+#endif
Code Review / kvmfornfv.git / blobdiff