u-boot/drivers/rtc/pcf2127.c

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/*
* Copyright (C) 2016 by NXP Semiconductors Inc.
* Date & Time support for PCF2127 RTC
*/
/* #define DEBUG */
#include <common.h>
#include <command.h>
#include <dm.h>
#include <i2c.h>
#include <rtc.h>
#define PCF2127_REG_CTRL1 0x00
#define PCF2127_REG_CTRL2 0x01
#define PCF2127_REG_CTRL3 0x02
#define PCF2127_REG_SC 0x03
#define PCF2127_REG_MN 0x04
#define PCF2127_REG_HR 0x05
#define PCF2127_REG_DM 0x06
#define PCF2127_REG_DW 0x07
#define PCF2127_REG_MO 0x08
#define PCF2127_REG_YR 0x09
static int pcf2127_read_reg(struct udevice *dev, uint offset,
u8 *buffer, int len)
{
struct dm_i2c_chip *chip = dev_get_parent_platdata(dev);
struct i2c_msg msg;
int ret;
/* Set the address of the start register to be read */
ret = dm_i2c_write(dev, offset, NULL, 0);
if (ret < 0)
return ret;
/* Read register's data */
msg.addr = chip->chip_addr;
msg.flags |= I2C_M_RD;
msg.len = len;
msg.buf = buffer;
return dm_i2c_xfer(dev, &msg, 1);
}
static int pcf2127_rtc_set(struct udevice *dev, const struct rtc_time *tm)
{
uchar buf[7] = {0};
int i = 0, ret;
/* hours, minutes and seconds */
buf[i++] = bin2bcd(tm->tm_sec);
buf[i++] = bin2bcd(tm->tm_min);
buf[i++] = bin2bcd(tm->tm_hour);
buf[i++] = bin2bcd(tm->tm_mday);
buf[i++] = tm->tm_wday & 0x07;
/* month, 1 - 12 */
buf[i++] = bin2bcd(tm->tm_mon + 1);
/* year */
buf[i++] = bin2bcd(tm->tm_year % 100);
/* write register's data */
ret = dm_i2c_write(dev, PCF2127_REG_SC, buf, i);
return ret;
}
static int pcf2127_rtc_get(struct udevice *dev, struct rtc_time *tm)
{
int ret = 0;
uchar buf[10] = { PCF2127_REG_CTRL1 };
ret = pcf2127_read_reg(dev, PCF2127_REG_CTRL1, buf, sizeof(buf));
if (ret < 0)
return ret;
if (buf[PCF2127_REG_CTRL3] & 0x04)
puts("### Warning: RTC Low Voltage - date/time not reliable\n");
tm->tm_sec = bcd2bin(buf[PCF2127_REG_SC] & 0x7F);
tm->tm_min = bcd2bin(buf[PCF2127_REG_MN] & 0x7F);
tm->tm_hour = bcd2bin(buf[PCF2127_REG_HR] & 0x3F);
tm->tm_mday = bcd2bin(buf[PCF2127_REG_DM] & 0x3F);
tm->tm_mon = bcd2bin(buf[PCF2127_REG_MO] & 0x1F) - 1;
tm->tm_year = bcd2bin(buf[PCF2127_REG_YR]) + 1900;
if (tm->tm_year < 1970)
tm->tm_year += 100; /* assume we are in 1970...2069 */
tm->tm_wday = buf[PCF2127_REG_DW] & 0x07;
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 ret;
}
static int pcf2127_rtc_reset(struct udevice *dev)
{
/*Doing nothing here*/
return 0;
}
static const struct rtc_ops pcf2127_rtc_ops = {
.get = pcf2127_rtc_get,
.set = pcf2127_rtc_set,
.reset = pcf2127_rtc_reset,
};
static const struct udevice_id pcf2127_rtc_ids[] = {
{ .compatible = "pcf2127-rtc" },
{ }
};
U_BOOT_DRIVER(rtc_pcf2127) = {
.name = "rtc-pcf2127",
.id = UCLASS_RTC,
.of_match = pcf2127_rtc_ids,
.ops = &pcf2127_rtc_ops,
};