u-boot/rtc/rs5c372.c

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/*
* rs5c372.c
*
* Device driver for Ricoh's Real Time Controller RS5C372A.
*
* Copyright (C) 2004 Gary Jennejohn garyj@denx.de
*
* Based in part in ds1307.c -
* (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
*
* See file CREDITS for list of people who contributed to this
* project.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <command.h>
#include <rtc.h>
#include <i2c.h>
#if defined(CONFIG_RTC_RS5C372A) && (CONFIG_COMMANDS & CFG_CMD_DATE)
/*
* Reads are always done starting with register 15, which requires some
* jumping-through-hoops to access the data correctly.
*
* Writes are always done starting with register 0.
*/
#define DEBUG 0
#if DEBUG
static unsigned int rtc_debug = DEBUG;
#else
#define rtc_debug 0 /* gcc will remove all the debug code for us */
#endif
#ifndef CFG_I2C_RTC_ADDR
#define CFG_I2C_RTC_ADDR 0x32
#endif
#define RS5C372_RAM_SIZE 0x10
#define RATE_32000HZ 0x80 /* Rate Select 32.000KHz */
#define RATE_32768HZ 0x00 /* Rate Select 32.768KHz */
#define STATUS_XPT 0x10 /* data invalid because voltage was 0 */
#define USE_24HOUR_MODE 0x20
#define TWELVE_HOUR_MODE(n) ((((n) >> 5) & 1) == 0)
#define HOURS_AP(n) (((n) >> 5) & 1)
#define HOURS_12(n) bcd2bin((n) & 0x1F)
#define HOURS_24(n) bcd2bin((n) & 0x3F)
static uchar bin2bcd (unsigned int n);
static unsigned bcd2bin (uchar c);
static int setup_done = 0;
static int
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rs5c372_readram(unsigned char *buf, int len)
{
int ret;
ret = i2c_read(CFG_I2C_RTC_ADDR, 0, 0, buf, len);
if (ret != 0) {
printf("%s: failed to read\n", __FUNCTION__);
return ret;
}
if (buf[0] & STATUS_XPT)
printf("### Warning: RTC lost power\n");
return ret;
}
static void
rs5c372_enable(void)
{
unsigned char buf[RS5C372_RAM_SIZE + 1];
int ret;
/* note that this returns reg. 15 in buf[1] */
ret = rs5c372_readram(&buf[1], RS5C372_RAM_SIZE);
if (ret != 0) {
printf("%s: failed\n", __FUNCTION__);
return;
}
buf[0] = 0;
/* we want to start writing at register 0 so we have to copy the */
/* register contents up one slot */
for (ret = 2; ret < 9; ret++)
buf[ret - 1] = buf[ret];
/* registers 0 to 6 (time values) are not touched */
buf[8] = RATE_32768HZ; /* reg. 7 */
buf[9] = 0; /* reg. 8 */
buf[10] = 0; /* reg. 9 */
buf[11] = 0; /* reg. 10 */
buf[12] = 0; /* reg. 11 */
buf[13] = 0; /* reg. 12 */
buf[14] = 0; /* reg. 13 */
buf[15] = 0; /* reg. 14 */
buf[16] = USE_24HOUR_MODE; /* reg. 15 */
ret = i2c_write(CFG_I2C_RTC_ADDR, 0, 0, buf, RS5C372_RAM_SIZE+1);
if (ret != 0) {
printf("%s: failed\n", __FUNCTION__);
return;
}
setup_done = 1;
return;
}
static void
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rs5c372_convert_to_time(struct rtc_time *dt, unsigned char *buf)
{
/* buf[0] is register 15 */
dt->tm_sec = bcd2bin(buf[1]);
dt->tm_min = bcd2bin(buf[2]);
if (TWELVE_HOUR_MODE(buf[0])) {
dt->tm_hour = HOURS_12(buf[3]);
if (HOURS_AP(buf[3])) /* PM */
dt->tm_hour += 12;
} else /* 24-hour-mode */
dt->tm_hour = HOURS_24(buf[3]);
dt->tm_mday = bcd2bin(buf[5]);
dt->tm_mon = bcd2bin(buf[6]);
dt->tm_year = bcd2bin(buf[7]);
if (dt->tm_year >= 70)
dt->tm_year += 1900;
else
dt->tm_year += 2000;
/* 0 is Sunday */
dt->tm_wday = bcd2bin(buf[4] & 0x07);
dt->tm_yday = 0;
dt->tm_isdst= 0;
if(rtc_debug > 2) {
printf("rs5c372_convert_to_time: year = %d\n", dt->tm_year);
printf("rs5c372_convert_to_time: mon = %d\n", dt->tm_mon);
printf("rs5c372_convert_to_time: mday = %d\n", dt->tm_mday);
printf("rs5c372_convert_to_time: hour = %d\n", dt->tm_hour);
printf("rs5c372_convert_to_time: min = %d\n", dt->tm_min);
printf("rs5c372_convert_to_time: sec = %d\n", dt->tm_sec);
}
}
/*
* Get the current time from the RTC
*/
void
rtc_get (struct rtc_time *tmp)
{
unsigned char buf[RS5C372_RAM_SIZE];
int ret;
if (!setup_done)
rs5c372_enable();
if (!setup_done)
return;
memset(buf, 0, sizeof(buf));
/* note that this returns reg. 15 in buf[0] */
ret = rs5c372_readram(buf, RS5C372_RAM_SIZE);
if (ret != 0) {
printf("%s: failed\n", __FUNCTION__);
return;
}
rs5c372_convert_to_time(tmp, buf);
return;
}
/*
* Set the RTC
*/
void
rtc_set (struct rtc_time *tmp)
{
unsigned char buf[8], reg15;
int ret;
if (!setup_done)
rs5c372_enable();
if (!setup_done)
return;
if(rtc_debug > 2) {
printf("rtc_set: tm_year = %d\n", tmp->tm_year);
printf("rtc_set: tm_mon = %d\n", tmp->tm_mon);
printf("rtc_set: tm_mday = %d\n", tmp->tm_mday);
printf("rtc_set: tm_hour = %d\n", tmp->tm_hour);
printf("rtc_set: tm_min = %d\n", tmp->tm_min);
printf("rtc_set: tm_sec = %d\n", tmp->tm_sec);
}
memset(buf, 0, sizeof(buf));
/* only read register 15 */
ret = i2c_read(CFG_I2C_RTC_ADDR, 0, 0, buf, 1);
if (ret == 0) {
/* need to save register 15 */
reg15 = buf[0];
buf[0] = 0; /* register address on RS5C372 */
buf[1] = bin2bcd(tmp->tm_sec);
buf[2] = bin2bcd(tmp->tm_min);
/* need to handle 12 hour mode */
if (TWELVE_HOUR_MODE(reg15)) {
if (tmp->tm_hour >= 12) { /* PM */
/* 12 PM is a special case */
if (tmp->tm_hour == 12)
buf[3] = bin2bcd(tmp->tm_hour);
else
buf[3] = bin2bcd(tmp->tm_hour - 12);
buf[3] |= 0x20;
}
} else {
buf[3] = bin2bcd(tmp->tm_hour);
}
buf[4] = bin2bcd(tmp->tm_wday);
buf[5] = bin2bcd(tmp->tm_mday);
buf[6] = bin2bcd(tmp->tm_mon);
if (tmp->tm_year < 1970 || tmp->tm_year > 2069)
printf("WARNING: year should be between 1970 and 2069!\n");
buf[7] = bin2bcd(tmp->tm_year % 100);
ret = i2c_write(CFG_I2C_RTC_ADDR, 0, 0, buf, 8);
if (ret != 0)
printf("rs5c372_set_datetime(), i2c_master_send() returned %d\n",ret);
}
return;
}
/*
* Reset the RTC. We set the date back to 1970-01-01.
*/
void
rtc_reset (void)
{
struct rtc_time tmp;
if (!setup_done)
rs5c372_enable();
if (!setup_done)
return;
tmp.tm_year = 1970;
tmp.tm_mon = 1;
/* Jan. 1, 1970 was a Thursday */
tmp.tm_wday= 4;
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;
}
static unsigned int
bcd2bin (unsigned char n)
{
return ((((n >> 4) & 0x0F) * 10) + (n & 0x0F));
}
static unsigned char
bin2bcd (unsigned int n)
{
return (((n / 10) << 4) | (n % 10));
}
#endif /* defined(CONFIG_RTC_RS5C372A) && (CONFIG_COMMANDS & CFG_CMD_DATE) */