u-boot/drivers/rtc/rv8803.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Date & Time support for Micro Crystal RV-8803-C7.
*
* based on ds1307.c which is
* (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
*
*/
#include <common.h>
#include <command.h>
#include <dm.h>
#include <rtc.h>
#include <i2c.h>
/*
* RTC register addresses
*/
#define RTC_SEC_REG_ADDR 0x00
#define RTC_MIN_REG_ADDR 0x01
#define RTC_HR_REG_ADDR 0x02
#define RTC_DAY_REG_ADDR 0x03
#define RTC_DATE_REG_ADDR 0x04
#define RTC_MON_REG_ADDR 0x05
#define RTC_YR_REG_ADDR 0x06
#define RTC_FLAG_REG_ADDR 0x0E
#define RTC_FLAG_BIT_V1F BIT(0)
#define RTC_FLAG_BIT_V2F BIT(1)
#define RTC_CTL_REG_ADDR 0x0F
#define RTC_CTL_BIT_RST BIT(0)
static int rv8803_rtc_set(struct udevice *dev, const struct rtc_time *tm)
{
int ret;
u8 buf[7];
debug("Set DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
if (tm->tm_year < 2000 || tm->tm_year > 2099)
printf("WARNING: year should be between 2000 and 2099!\n");
buf[RTC_YR_REG_ADDR] = bin2bcd(tm->tm_year % 100);
buf[RTC_MON_REG_ADDR] = bin2bcd(tm->tm_mon);
buf[RTC_DAY_REG_ADDR] = 1 << (tm->tm_wday & 0x7);
buf[RTC_DATE_REG_ADDR] = bin2bcd(tm->tm_mday);
buf[RTC_HR_REG_ADDR] = bin2bcd(tm->tm_hour);
buf[RTC_MIN_REG_ADDR] = bin2bcd(tm->tm_min);
buf[RTC_SEC_REG_ADDR] = bin2bcd(tm->tm_sec);
ret = dm_i2c_write(dev, 0, buf, sizeof(buf));
if (ret < 0)
return ret;
return 0;
}
static int rv8803_rtc_get(struct udevice *dev, struct rtc_time *tm)
{
int ret;
u8 buf[7];
int flags;
flags = dm_i2c_reg_read(dev, RTC_FLAG_REG_ADDR);
if (flags < 0)
return flags;
debug("%s: flags=%Xh\n", __func__, flags);
if (flags & RTC_FLAG_BIT_V1F)
printf("### Warning: temperature compensation has stopped\n");
if (flags & RTC_FLAG_BIT_V2F) {
printf("### Warning: Voltage low, data is invalid\n");
return -1;
}
ret = dm_i2c_read(dev, 0, buf, sizeof(buf));
if (ret < 0)
return ret;
tm->tm_sec = bcd2bin(buf[RTC_SEC_REG_ADDR] & 0x7F);
tm->tm_min = bcd2bin(buf[RTC_MIN_REG_ADDR] & 0x7F);
tm->tm_hour = bcd2bin(buf[RTC_HR_REG_ADDR] & 0x3F);
tm->tm_mday = bcd2bin(buf[RTC_DATE_REG_ADDR] & 0x3F);
tm->tm_mon = bcd2bin(buf[RTC_MON_REG_ADDR] & 0x1F);
tm->tm_year = bcd2bin(buf[RTC_YR_REG_ADDR]) + 2000;
tm->tm_wday = fls(buf[RTC_DAY_REG_ADDR] & 0x7F) - 1;
tm->tm_yday = 0;
tm->tm_isdst = 0;
debug("Get DATE: %4d-%02d-%02d (wday=%d) TIME: %2d:%02d:%02d\n",
tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_wday,
tm->tm_hour, tm->tm_min, tm->tm_sec);
return 0;
}
static int rv8803_rtc_reset(struct udevice *dev)
{
int ret;
struct rtc_time tmp = {
.tm_year = 2000,
.tm_mon = 1,
.tm_mday = 1,
.tm_hour = 0,
.tm_min = 0,
.tm_sec = 0,
};
/* assert reset */
ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR, RTC_CTL_BIT_RST);
if (ret < 0)
return ret;
/* clear all flags */
ret = dm_i2c_reg_write(dev, RTC_FLAG_REG_ADDR, 0);
if (ret < 0)
return ret;
ret = rv8803_rtc_set(dev, &tmp);
if (ret < 0)
return ret;
/* clear reset */
ret = dm_i2c_reg_write(dev, RTC_CTL_REG_ADDR, 0);
if (ret < 0)
return ret;
debug("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 0;
}
static int rv8803_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 rv8803_rtc_ops = {
.get = rv8803_rtc_get,
.set = rv8803_rtc_set,
.reset = rv8803_rtc_reset,
};
static const struct udevice_id rv8803_rtc_ids[] = {
{ .compatible = "microcrystal,rv8803", },
{ }
};
U_BOOT_DRIVER(rtc_rv8803) = {
.name = "rtc-rv8803",
.id = UCLASS_RTC,
.probe = rv8803_probe,
.of_match = rv8803_rtc_ids,
.ops = &rv8803_rtc_ops,
};