u-boot/drivers/rtc/isl1208.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2008
* Tor Krill, Excito Elektronik i Skåne , tor@excito.com
*
* Modelled after the ds1337 driver
*/
/*
* Date & Time support (no alarms) for Intersil
* ISL1208 Real Time Clock (RTC).
*/
#include <common.h>
#include <command.h>
#include <dm.h>
#include <rtc.h>
#include <i2c.h>
/*---------------------------------------------------------------------*/
#ifdef DEBUG_RTC
#define DEBUGR(fmt,args...) printf(fmt ,##args)
#else
#define DEBUGR(fmt,args...)
#endif
/*---------------------------------------------------------------------*/
/*
* RTC register addresses
*/
#define RTC_SEC_REG_ADDR 0x0
#define RTC_MIN_REG_ADDR 0x1
#define RTC_HR_REG_ADDR 0x2
#define RTC_DATE_REG_ADDR 0x3
#define RTC_MON_REG_ADDR 0x4
#define RTC_YR_REG_ADDR 0x5
#define RTC_DAY_REG_ADDR 0x6
#define RTC_STAT_REG_ADDR 0x7
/*
* RTC control register bits
*/
/*
* RTC status register bits
*/
#define RTC_STAT_BIT_ARST 0x80 /* AUTO RESET ENABLE BIT */
#define RTC_STAT_BIT_XTOSCB 0x40 /* CRYSTAL OSCILLATOR ENABLE BIT */
#define RTC_STAT_BIT_WRTC 0x10 /* WRITE RTC ENABLE BIT */
#define RTC_STAT_BIT_ALM 0x04 /* ALARM BIT */
#define RTC_STAT_BIT_BAT 0x02 /* BATTERY BIT */
#define RTC_STAT_BIT_RTCF 0x01 /* REAL TIME CLOCK FAIL BIT */
/*
* Get the current time from the RTC
*/
static int isl1208_rtc_get(struct udevice *dev, struct rtc_time *tmp)
{
int ret;
uchar buf[8], val;
ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
if (ret < 0)
return ret;
if (buf[RTC_STAT_REG_ADDR] & RTC_STAT_BIT_RTCF) {
printf ("### Warning: RTC oscillator has stopped\n");
ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
if (ret < 0)
return ret;
val = val & ~(RTC_STAT_BIT_BAT | RTC_STAT_BIT_RTCF);
ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
if (ret < 0)
return ret;
}
tmp->tm_sec = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
tmp->tm_min = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
tmp->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
tmp->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
tmp->tm_mon = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
tmp->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) + 2000;
tmp->tm_wday = bcd2bin(buf[RTC_DAY_REG_ADDR] & 0x07);
tmp->tm_yday = 0;
tmp->tm_isdst= 0;
DEBUGR ("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);
return 0;
}
/*
* Set the RTC
*/
static int isl1208_rtc_set(struct udevice *dev, const struct rtc_time *tmp)
{
int ret;
uchar val, buf[7];
DEBUGR ("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);
if (tmp->tm_year < 2000 || tmp->tm_year > 2099)
printf("WARNING: year should be between 2000 and 2099!\n");
/* enable write */
ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
if (ret < 0)
return ret;
val = val | RTC_STAT_BIT_WRTC;
ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
if (ret < 0)
return ret;
buf[RTC_YR_REG_ADDR] = bin2bcd(tmp->tm_year % 100);
buf[RTC_MON_REG_ADDR] = bin2bcd(tmp->tm_mon);
buf[RTC_DAY_REG_ADDR] = bin2bcd(tmp->tm_wday);
buf[RTC_DATE_REG_ADDR] = bin2bcd(tmp->tm_mday);
buf[RTC_HR_REG_ADDR] = bin2bcd(tmp->tm_hour) | 0x80; /* 24h clock */
buf[RTC_MIN_REG_ADDR] = bin2bcd(tmp->tm_min);
buf[RTC_SEC_REG_ADDR] = bin2bcd(tmp->tm_sec);
ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
if (ret < 0)
return ret;
/* disable write */
ret = dm_i2c_read(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
if (ret < 0)
return ret;
val = val & ~RTC_STAT_BIT_WRTC;
ret = dm_i2c_write(dev, RTC_STAT_REG_ADDR, &val, sizeof(val));
if (ret < 0)
return ret;
return 0;
}
static int isl1208_rtc_reset(struct udevice *dev)
{
return 0;
}
static int isl1208_probe(struct udevice *dev)
{
i2c_set_chip_flags(dev, DM_I2C_CHIP_RD_ADDRESS |
DM_I2C_CHIP_WR_ADDRESS);
return 0;
}
static const struct rtc_ops isl1208_rtc_ops = {
.get = isl1208_rtc_get,
.set = isl1208_rtc_set,
.reset = isl1208_rtc_reset,
};
static const struct udevice_id isl1208_rtc_ids[] = {
{ .compatible = "isil,isl1208" },
{ }
};
U_BOOT_DRIVER(rtc_isl1208) = {
.name = "rtc-isl1208",
.id = UCLASS_RTC,
.probe = isl1208_probe,
.of_match = isl1208_rtc_ids,
.ops = &isl1208_rtc_ops,
};