/* * 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) = ystatic unsigned long rtc_base;static unsigned longrtc_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;}voidrtc_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;}