u-boot/board/etin/debris/phantom.c

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/*
* board/eva/phantom.c
*
* Phantom RTC device driver for EVA
*
* Author: Sangmoon Kim
* dogoil@etinsys.com
*
* Copyright 2002 Etinsys Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <command.h>
#include <rtc.h>
#if defined(CONFIG_CMD_DATE)
#define RTC_BASE (CONFIG_SYS_NVRAM_BASE_ADDR + 0x7fff8)
#define RTC_YEAR ( RTC_BASE + 7 )
#define RTC_MONTH ( RTC_BASE + 6 )
#define RTC_DAY_OF_MONTH ( RTC_BASE + 5 )
#define RTC_DAY_OF_WEEK ( RTC_BASE + 4 )
#define RTC_HOURS ( RTC_BASE + 3 )
#define RTC_MINUTES ( RTC_BASE + 2 )
#define RTC_SECONDS ( RTC_BASE + 1 )
#define RTC_CENTURY ( RTC_BASE + 0 )
#define RTC_CONTROLA RTC_CENTURY
#define RTC_CONTROLB RTC_SECONDS
#define RTC_CONTROLC RTC_DAY_OF_WEEK
#define RTC_CA_WRITE 0x80
#define RTC_CA_READ 0x40
#define RTC_CB_OSC_DISABLE 0x80
#define RTC_CC_BATTERY_FLAG 0x80
#define RTC_CC_FREQ_TEST 0x40
static int phantom_flag = -1;
static int century_flag = -1;
static uchar rtc_read(unsigned int addr)
{
return *(volatile unsigned char *)(addr);
}
static void rtc_write(unsigned int addr, uchar val)
{
*(volatile unsigned char *)(addr) = val;
}
static unsigned char phantom_rtc_sequence[] = {
0xc5, 0x3a, 0xa3, 0x5c, 0xc5, 0x3a, 0xa3, 0x5c
};
static unsigned char* phantom_rtc_read(int addr, unsigned char rtc[8])
{
int i, j;
unsigned char v;
unsigned char save = rtc_read(addr);
for (j = 0; j < 8; j++) {
v = phantom_rtc_sequence[j];
for (i = 0; i < 8; i++) {
rtc_write(addr, v & 1);
v >>= 1;
}
}
for (j = 0; j < 8; j++) {
v = 0;
for (i = 0; i < 8; i++) {
if(rtc_read(addr) & 1)
v |= 1 << i;
}
rtc[j] = v;
}
rtc_write(addr, save);
return rtc;
}
static void phantom_rtc_write(int addr, unsigned char rtc[8])
{
int i, j;
unsigned char v;
unsigned char save = rtc_read(addr);
for (j = 0; j < 8; j++) {
v = phantom_rtc_sequence[j];
for (i = 0; i < 8; i++) {
rtc_write(addr, v & 1);
v >>= 1;
}
}
for (j = 0; j < 8; j++) {
v = rtc[j];
for (i = 0; i < 8; i++) {
rtc_write(addr, v & 1);
v >>= 1;
}
}
rtc_write(addr, save);
}
static int get_phantom_flag(void)
{
int i;
unsigned char rtc[8];
phantom_rtc_read(RTC_BASE, rtc);
for(i = 1; i < 8; i++) {
if (rtc[i] != rtc[0])
return 1;
}
return 0;
}
void rtc_reset(void)
{
if (phantom_flag < 0)
phantom_flag = get_phantom_flag();
if (phantom_flag) {
unsigned char rtc[8];
phantom_rtc_read(RTC_BASE, rtc);
if(rtc[4] & 0x30) {
printf( "real-time-clock was stopped. Now starting...\n" );
rtc[4] &= 0x07;
phantom_rtc_write(RTC_BASE, rtc);
}
} else {
uchar reg_a, reg_b, reg_c;
reg_a = rtc_read( RTC_CONTROLA );
reg_b = rtc_read( RTC_CONTROLB );
if ( reg_b & RTC_CB_OSC_DISABLE )
{
printf( "real-time-clock was stopped. Now starting...\n" );
reg_a |= RTC_CA_WRITE;
reg_b &= ~RTC_CB_OSC_DISABLE;
rtc_write( RTC_CONTROLA, reg_a );
rtc_write( RTC_CONTROLB, reg_b );
}
/* make sure read/write clock register bits are cleared */
reg_a &= ~( RTC_CA_WRITE | RTC_CA_READ );
rtc_write( RTC_CONTROLA, reg_a );
reg_c = rtc_read( RTC_CONTROLC );
if (( reg_c & RTC_CC_BATTERY_FLAG ) == 0 )
printf( "RTC battery low. Clock setting may not be reliable.\n");
}
}
static int get_century_flag(void)
{
int flag = 0;
int bcd, century;
bcd = rtc_read( RTC_CENTURY );
century = bcd2bin( bcd & 0x3F );
rtc_write( RTC_CENTURY, bin2bcd(century+1));
if (bcd == rtc_read( RTC_CENTURY ))
flag = 1;
rtc_write( RTC_CENTURY, bcd);
return flag;
}
int rtc_get( struct rtc_time *tmp)
{
if (phantom_flag < 0)
phantom_flag = get_phantom_flag();
if (phantom_flag)
{
unsigned char rtc[8];
phantom_rtc_read(RTC_BASE, rtc);
tmp->tm_sec = bcd2bin(rtc[1] & 0x7f);
tmp->tm_min = bcd2bin(rtc[2] & 0x7f);
tmp->tm_hour = bcd2bin(rtc[3] & 0x1f);
tmp->tm_wday = bcd2bin(rtc[4] & 0x7);
tmp->tm_mday = bcd2bin(rtc[5] & 0x3f);
tmp->tm_mon = bcd2bin(rtc[6] & 0x1f);
tmp->tm_year = bcd2bin(rtc[7]) + 1900;
tmp->tm_yday = 0;
tmp->tm_isdst = 0;
if( (rtc[3] & 0x80) && (rtc[3] & 0x40) ) tmp->tm_hour += 12;
if (tmp->tm_year < 1970) tmp->tm_year += 100;
} else {
uchar sec, min, hour;
uchar mday, wday, mon, year;
int century;
uchar reg_a;
if (century_flag < 0)
century_flag = get_century_flag();
reg_a = rtc_read( RTC_CONTROLA );
/* lock clock registers for read */
rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_READ ));
sec = rtc_read( RTC_SECONDS );
min = rtc_read( RTC_MINUTES );
hour = rtc_read( RTC_HOURS );
mday = rtc_read( RTC_DAY_OF_MONTH );
wday = rtc_read( RTC_DAY_OF_WEEK );
mon = rtc_read( RTC_MONTH );
year = rtc_read( RTC_YEAR );
century = rtc_read( RTC_CENTURY );
/* unlock clock registers after read */
rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_READ ));
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_wday = bcd2bin( wday & 0x07 );
if (century_flag) {
tmp->tm_year = bcd2bin( year ) +
( bcd2bin( century & 0x3F ) * 100 );
} else {
tmp->tm_year = bcd2bin( year ) + 1900;
if (tmp->tm_year < 1970) tmp->tm_year += 100;
}
tmp->tm_yday = 0;
tmp->tm_isdst= 0;
}
return 0;
}
int rtc_set( struct rtc_time *tmp )
{
if (phantom_flag < 0)
phantom_flag = get_phantom_flag();
if (phantom_flag) {
uint year;
unsigned char rtc[8];
year = tmp->tm_year;
year -= (year < 2000) ? 1900 : 2000;
rtc[0] = bin2bcd(0);
rtc[1] = bin2bcd(tmp->tm_sec);
rtc[2] = bin2bcd(tmp->tm_min);
rtc[3] = bin2bcd(tmp->tm_hour);
rtc[4] = bin2bcd(tmp->tm_wday);
rtc[5] = bin2bcd(tmp->tm_mday);
rtc[6] = bin2bcd(tmp->tm_mon);
rtc[7] = bin2bcd(year);
phantom_rtc_write(RTC_BASE, rtc);
} else {
uchar reg_a;
if (century_flag < 0)
century_flag = get_century_flag();
/* lock clock registers for write */
reg_a = rtc_read( RTC_CONTROLA );
rtc_write( RTC_CONTROLA, ( reg_a | RTC_CA_WRITE ));
rtc_write( RTC_MONTH, bin2bcd( tmp->tm_mon ));
rtc_write( RTC_DAY_OF_WEEK, bin2bcd( tmp->tm_wday ));
rtc_write( RTC_DAY_OF_MONTH, bin2bcd( tmp->tm_mday ));
rtc_write( RTC_HOURS, bin2bcd( tmp->tm_hour ));
rtc_write( RTC_MINUTES, bin2bcd( tmp->tm_min ));
rtc_write( RTC_SECONDS, bin2bcd( tmp->tm_sec ));
/* break year up into century and year in century */
if (century_flag) {
rtc_write( RTC_YEAR, bin2bcd( tmp->tm_year % 100 ));
rtc_write( RTC_CENTURY, bin2bcd( tmp->tm_year / 100 ));
reg_a &= 0xc0;
reg_a |= bin2bcd( tmp->tm_year / 100 );
} else {
rtc_write(RTC_YEAR, bin2bcd(tmp->tm_year -
((tmp->tm_year < 2000) ? 1900 : 2000)));
}
/* unlock clock registers after read */
rtc_write( RTC_CONTROLA, ( reg_a & ~RTC_CA_WRITE ));
}
return 0;
}
#endif