patch-2.4.10 linux/arch/mips/ddb5xxx/common/rtc_ds1386.c

• Lines: 168
• Date: Sun Sep 9 10:43:01 2001
• Orig file: v2.4.9/linux/arch/mips/ddb5xxx/common/rtc_ds1386.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.4.9/linux/arch/mips/ddb5xxx/common/rtc_ds1386.c linux/arch/mips/ddb5xxx/common/rtc_ds1386.c
@@ -0,0 +1,167 @@
+/*
+ * Copyright 2001 MontaVista Software Inc.
+ * Author: jsun@mvista.com or jsun@junsun.net
+ *
+ * arch/mips/ddb5xxx/common/rtc_ds1386.c
+ *     low-level RTC hookups for s for Dallas 1396 chip.
+ *
+ * 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 file exports a function, rtc_ds1386_init(), which expects an
+ * uncached base address as the argument.  It will set the two function
+ * pointers expected by the MIPS generic timer code.
+ */
+
+#include <linux/types.h>
+#include <linux/time.h>
+
+#include <asm/time.h>
+#include <asm/addrspace.h>
+
+#include <asm/ddb5xxx/debug.h>
+
+#define	EPOCH		2000
+
+#undef BCD_TO_BIN
+#define BCD_TO_BIN(val) (((val)&15) + ((val)>>4)*10)
+
+#undef BIN_TO_BCD
+#define BIN_TO_BCD(val) ((((val)/10)<<4) + (val)%10)
+
+#define	READ_RTC(x)	*(volatile unsigned char*)(rtc_base+x)
+#define	WRITE_RTC(x, y)	*(volatile unsigned char*)(rtc_base+x) = y
+
+static unsigned long rtc_base;
+
+static unsigned long
+rtc_ds1386_get_time(void)
+{	
+	u8 byte;
+	u8 temp;
+	unsigned int year, month, day, hour, minute, second;
+
+	/* let us freeze external registers */
+	byte = READ_RTC(0xB);
+	byte &= 0x3f;
+	WRITE_RTC(0xB, byte);
+
+	/* read time data */
+	year = BCD_TO_BIN(READ_RTC(0xA)) + EPOCH;
+	month = BCD_TO_BIN(READ_RTC(0x9) & 0x1f);
+	day = BCD_TO_BIN(READ_RTC(0x8));
+	minute = BCD_TO_BIN(READ_RTC(0x2));
+	second = BCD_TO_BIN(READ_RTC(0x1));
+
+	/* hour is special - deal with it later */
+	temp = READ_RTC(0x4);
+
+	/* enable time transfer */
+	byte |= 0x80;
+	WRITE_RTC(0xB, byte);
+
+	/* calc hour */
+	if (temp & 0x40) {
+		/* 12 hour format */
+		hour = BCD_TO_BIN(temp & 0x1f);
+		if (temp & 0x20) hour += 12; 		/* PM */
+	} else {
+		/* 24 hour format */
+		hour = BCD_TO_BIN(temp & 0x3f);
+	}
+
+	return mktime(year, month, day, hour, minute, second);
+}
+
+static int 
+rtc_ds1386_set_time(unsigned long t)
+{
+	struct rtc_time tm;
+	u8 byte;
+	u8 temp;
+	u8 year, month, day, hour, minute, second;
+
+	/* let us freeze external registers */
+	byte = READ_RTC(0xB);
+	byte &= 0x3f;
+	WRITE_RTC(0xB, byte);
+
+	/* convert */
+	to_tm(t, &tm);
+
+	/* check each field one by one */
+	year = BIN_TO_BCD(tm.tm_year - EPOCH);
+	if (year != READ_RTC(0xA)) {
+		WRITE_RTC(0xA, year);
+	}
+
+	temp = READ_RTC(0x9);
+	month = BIN_TO_BCD(tm.tm_mon);
+	if (month != (temp & 0x1f)) {
+		WRITE_RTC( 0x9,
+			   (month & 0x1f) | (temp & ~0x1f) );
+	}
+
+	day = BIN_TO_BCD(tm.tm_mday);
+	if (day != READ_RTC(0x8)) {
+		WRITE_RTC(0x8, day);
+	}
+
+	temp = READ_RTC(0x4);
+	if (temp & 0x40) {
+		/* 12 hour format */
+		hour = 0x40;
+		if (tm.tm_hour > 12) {
+			hour |= 0x20 | (BIN_TO_BCD(hour-12) & 0x1f);
+		} else {
+			hour |= BIN_TO_BCD(tm.tm_hour);
+		}
+	} else {
+		/* 24 hour format */
+		hour = BIN_TO_BCD(tm.tm_hour) & 0x3f;
+	}
+	if (hour != temp) WRITE_RTC(0x4, hour);
+
+	minute = BIN_TO_BCD(tm.tm_min);
+	if (minute != READ_RTC(0x2)) {
+		WRITE_RTC(0x2, minute);
+	}
+
+	second = BIN_TO_BCD(tm.tm_sec);
+	if (second != READ_RTC(0x1)) {
+		WRITE_RTC(0x1, second);
+	}
+	
+	return 0;
+}
+
+void
+rtc_ds1386_init(unsigned long base)
+{
+	unsigned char byte;
+	
+	/* remember the base */
+	rtc_base = base;
+	MIPS_ASSERT((rtc_base & 0xe0000000) == KSEG1);
+
+	/* turn on RTC if it is not on */
+	byte = READ_RTC(0x9);
+	if (byte & 0x80) {
+		byte &= 0x7f;
+		WRITE_RTC(0x9, byte);
+	}
+
+	/* enable time transfer */
+	byte = READ_RTC(0xB);
+	byte |= 0x80;
+	WRITE_RTC(0xB, byte);
+
+	/* set the function pointers */
+	rtc_get_time = rtc_ds1386_get_time;
+	rtc_set_time = rtc_ds1386_set_time;
+}