mc146818.c
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/*
* (C) Copyright 2001
* Denis Peter MPL AG Switzerland. d.peter@mpl.ch
*
* SPDX-License-Identifier: GPL-2.0+
*/
/*
* Date & Time support for the MC146818 (PIXX4) RTC
*/
/*#define DEBUG*/
#include <common.h>
#include <command.h>
#include <rtc.h>
#if defined(__I386__) || defined(CONFIG_MALTA)
#include <asm/io.h>
#define in8(p) inb(p)
#define out8(p, v) outb(v, p)
#endif
#if defined(CONFIG_CMD_DATE)
/* Set this to 1 to clear the CMOS RAM */
#define CLEAR_CMOS 0
#define RTC_PORT_MC146818 CONFIG_SYS_ISA_IO_BASE_ADDRESS + 0x70
#define RTC_SECONDS 0x00
#define RTC_SECONDS_ALARM 0x01
#define RTC_MINUTES 0x02
#define RTC_MINUTES_ALARM 0x03
#define RTC_HOURS 0x04
#define RTC_HOURS_ALARM 0x05
#define RTC_DAY_OF_WEEK 0x06
#define RTC_DATE_OF_MONTH 0x07
#define RTC_MONTH 0x08
#define RTC_YEAR 0x09
#define RTC_CONFIG_A 0x0A
#define RTC_CONFIG_B 0x0B
#define RTC_CONFIG_C 0x0C
#define RTC_CONFIG_D 0x0D
#define RTC_REG_SIZE 0x80
#define RTC_CONFIG_A_REF_CLCK_32KHZ (1 << 5)
#define RTC_CONFIG_A_RATE_1024HZ 6
#define RTC_CONFIG_B_24H (1 << 1)
#define RTC_CONFIG_D_VALID_RAM_AND_TIME 0x80
/* ------------------------------------------------------------------------- */
int rtc_get (struct rtc_time *tmp)
{
uchar sec, min, hour, mday, wday, mon, year;
/* here check if rtc can be accessed */
while ((rtc_read8(RTC_CONFIG_A) & 0x80) == 0x80);
sec = rtc_read8(RTC_SECONDS);
min = rtc_read8(RTC_MINUTES);
hour = rtc_read8(RTC_HOURS);
mday = rtc_read8(RTC_DATE_OF_MONTH);
wday = rtc_read8(RTC_DAY_OF_WEEK);
mon = rtc_read8(RTC_MONTH);
year = rtc_read8(RTC_YEAR);
#ifdef RTC_DEBUG
printf ( "Get RTC year: %02x mon/cent: %02x mday: %02x wday: %02x "
"hr: %02x min: %02x sec: %02x\n",
year, mon, mday, wday,
hour, min, sec );
printf ( "Alarms: month: %02x hour: %02x min: %02x sec: %02x\n",
rtc_read8(RTC_CONFIG_D) & 0x3F,
rtc_read8(RTC_HOURS_ALARM),
rtc_read8(RTC_MINUTES_ALARM),
rtc_read8(RTC_SECONDS_ALARM));
#endif
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);
tmp->tm_wday = bcd2bin (wday & 0x07);
if(tmp->tm_year<70)
tmp->tm_year+=2000;
else
tmp->tm_year+=1900;
tmp->tm_yday = 0;
tmp->tm_isdst= 0;
#ifdef RTC_DEBUG
printf ( "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);
#endif
return 0;
}
int rtc_set (struct rtc_time *tmp)
{
#ifdef RTC_DEBUG
printf ( "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);
#endif
rtc_write8(RTC_CONFIG_B, 0x82); /* disable the RTC to update the regs */
rtc_write8(RTC_YEAR, bin2bcd(tmp->tm_year % 100));
rtc_write8(RTC_MONTH, bin2bcd(tmp->tm_mon));
rtc_write8(RTC_DAY_OF_WEEK, bin2bcd(tmp->tm_wday));
rtc_write8(RTC_DATE_OF_MONTH, bin2bcd(tmp->tm_mday));
rtc_write8(RTC_HOURS, bin2bcd(tmp->tm_hour));
rtc_write8(RTC_MINUTES, bin2bcd(tmp->tm_min));
rtc_write8(RTC_SECONDS, bin2bcd(tmp->tm_sec));
rtc_write8(RTC_CONFIG_B, 0x02); /* enable the RTC to update the regs */
return 0;
}
void rtc_reset (void)
{
rtc_write8(RTC_CONFIG_B, 0x82); /* disable the RTC to update the regs */
rtc_write8(RTC_CONFIG_A, 0x20); /* Normal OP */
rtc_write8(RTC_CONFIG_B, 0x00);
rtc_write8(RTC_CONFIG_B, 0x00);
rtc_write8(RTC_CONFIG_B, 0x02); /* enable the RTC to update the regs */
}
/* ------------------------------------------------------------------------- */
/*
* use direct memory access
*/
int rtc_read8(int reg)
{
#ifdef CONFIG_SYS_RTC_REG_BASE_ADDR
return in8(CONFIG_SYS_RTC_REG_BASE_ADDR + reg);
#else
int ofs = 0;
if (reg >= 128) {
ofs = 2;
reg -= 128;
}
out8(RTC_PORT_MC146818 + ofs, reg);
return in8(RTC_PORT_MC146818 + ofs + 1);
#endif
}
void rtc_write8(int reg, uchar val)
{
#ifdef CONFIG_SYS_RTC_REG_BASE_ADDR
out8(CONFIG_SYS_RTC_REG_BASE_ADDR + reg, val);
#else
int ofs = 0;
if (reg >= 128) {
ofs = 2;
reg -= 128;
}
out8(RTC_PORT_MC146818 + ofs, reg);
out8(RTC_PORT_MC146818 + ofs + 1, val);
#endif
}
u32 rtc_read32(int reg)
{
u32 value = 0;
int i;
for (i = 0; i < sizeof(value); i++)
value |= rtc_read8(reg + i) << (i << 3);
return value;
}
void rtc_write32(int reg, u32 value)
{
int i;
for (i = 0; i < sizeof(value); i++)
rtc_write8(reg + i, (value >> (i << 3)) & 0xff);
}
void rtc_init(void)
{
#if CLEAR_CMOS
int i;
rtc_write8(RTC_SECONDS_ALARM, 0);
rtc_write8(RTC_MINUTES_ALARM, 0);
rtc_write8(RTC_HOURS_ALARM, 0);
for (i = RTC_CONFIG_A; i < RTC_REG_SIZE; i++)
rtc_write8(i, 0);
printf("RTC: zeroing CMOS RAM\n");
#endif
/* Setup the real time clock */
rtc_write8(RTC_CONFIG_B, RTC_CONFIG_B_24H);
/* Setup the frequency it operates at */
rtc_write8(RTC_CONFIG_A, RTC_CONFIG_A_REF_CLCK_32KHZ |
RTC_CONFIG_A_RATE_1024HZ);
/* Ensure all reserved bits are 0 in register D */
rtc_write8(RTC_CONFIG_D, RTC_CONFIG_D_VALID_RAM_AND_TIME);
/* Clear any pending interrupts */
rtc_read8(RTC_CONFIG_C);
}
#endif