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/*
* This file is part of the coreboot project.
*
* Copyright 2017 Siemens AG.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* 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.
*/
#include <device/i2c.h>
#include <device/smbus.h>
#include <device/device.h>
#include <version.h>
#include <console/console.h>
#include <bcd.h>
#include "chip.h"
#include "rx6110sa.h"
#define I2C_BUS_NUM (dev->bus->secondary - 1)
#define I2C_DEV_NUM (dev->path.i2c.device)
/* Function to write a register in the RTC with the given value. */
static void rx6110sa_write(struct device *dev, uint8_t reg, uint8_t val)
{
if (IS_ENABLED(CONFIG_RX6110SA_USE_SMBUS))
smbus_write_byte(dev, reg, val);
else
i2c_writeb(I2C_BUS_NUM, I2C_DEV_NUM, reg, val);
}
/* Function to read a register in the RTC. */
static uint8_t rx6110sa_read(struct device *dev, uint8_t reg)
{
uint8_t val = 0;
if (IS_ENABLED(CONFIG_RX6110SA_USE_SMBUS))
val = smbus_read_byte(dev, reg);
else
i2c_readb(I2C_BUS_NUM, I2C_DEV_NUM, reg, &val);
return val;
}
/* Set RTC date from coreboot build date. */
static void rx6110sa_set_build_date(struct device *dev)
{
rx6110sa_write(dev, YEAR_REG, coreboot_build_date.year);
rx6110sa_write(dev, MONTH_REG, coreboot_build_date.month);
rx6110sa_write(dev, DAY_REG, coreboot_build_date.day);
rx6110sa_write(dev, WEEK_REG, (1 << coreboot_build_date.weekday));
}
/* Set RTC date from user defined date (available in e.g. device tree). */
static void rx6110sa_set_user_date(struct device *dev)
{
struct drivers_i2c_rx6110sa_config *config = dev->chip_info;
rx6110sa_write(dev, YEAR_REG, bin2bcd(config->user_year));
rx6110sa_write(dev, MONTH_REG, bin2bcd(config->user_month));
rx6110sa_write(dev, DAY_REG, bin2bcd(config->user_day));
rx6110sa_write(dev, WEEK_REG, (1 << config->user_weekday));
}
static void rx6110sa_final(struct device *dev)
{
uint8_t hour, minute, second, year, month, day;
/* Read back current RTC date and time and print it to the console. */
hour = rx6110sa_read(dev, HOUR_REG);
minute = rx6110sa_read(dev, MINUTE_REG);
second = rx6110sa_read(dev, SECOND_REG);
year = rx6110sa_read(dev, YEAR_REG);
month = rx6110sa_read(dev, MONTH_REG);
day = rx6110sa_read(dev, DAY_REG);
printk(BIOS_INFO, "%s: Current date %02d.%02d.%02d %02d:%02d:%02d\n",
dev->chip_ops->name, bcd2bin(month), bcd2bin(day),
bcd2bin(year), bcd2bin(hour), bcd2bin(minute), bcd2bin(second));
}
static void rx6110sa_init(struct device *dev)
{
struct drivers_i2c_rx6110sa_config *config = dev->chip_info;
uint8_t reg;
/* Do a dummy read first. */
reg = rx6110sa_read(dev, SECOND_REG);
/*
* Check VLF-bit which indicates the RTC data loss, such as due to a
* supply voltage drop.
*/
reg = rx6110sa_read(dev, FLAG_REGISTER);
if (!(reg & VLF_BIT))
/* No voltage low detected, everything is well. */
return;
/*
* Voltage low detected, initialize RX6110 SA again.
* Set first some registers to known state.
*/
rx6110sa_write(dev, BATTERY_BACKUP_REG, 0x00);
rx6110sa_write(dev, RESERVED_BIT_REG, RTC_INIT_VALUE);
rx6110sa_write(dev, DIGITAL_REG, 0x00);
rx6110sa_write(dev, IRQ_CONTROL_REG, 0x00);
/* Clear timer enable bit and set frequency of clock output. */
reg = rx6110sa_read(dev, EXTENSION_REG);
reg &= ~(FSEL_MASK | TE_BIT);
reg |= (config->cof_selection << 6);
rx6110sa_write(dev, EXTENSION_REG, reg);
/* Clear voltage low detect bit. */
reg = rx6110sa_read(dev, FLAG_REGISTER);
reg &= ~VLF_BIT;
rx6110sa_write(dev, FLAG_REGISTER, reg);
/* Before setting the clock stop oscillator. */
rx6110sa_write(dev, CTRL_REG, STOP_BIT);
if (config->set_user_date) {
/* Set user date defined in device tree. */
printk(BIOS_DEBUG, "%s: Set to user date\n",
dev->chip_ops->name);
rx6110sa_set_user_date(dev);
} else {
/* Set date from coreboot build. */
printk(BIOS_DEBUG, "%s: Set to coreboot build date\n",
dev->chip_ops->name);
rx6110sa_set_build_date(dev);
}
rx6110sa_write(dev, HOUR_REG, 1);
rx6110sa_write(dev, MINUTE_REG, 0);
rx6110sa_write(dev, SECOND_REG, 0);
/* Start oscillator again as the RTC is set up now. */
rx6110sa_write(dev, CTRL_REG, 0x00);
}
static struct device_operations rx6110sa_ops = {
.read_resources = DEVICE_NOOP,
.set_resources = DEVICE_NOOP,
.enable_resources = DEVICE_NOOP,
.init = rx6110sa_init,
.final = rx6110sa_final
};
static void rx6110sa_enable(struct device *dev)
{
dev->ops = &rx6110sa_ops;
}
struct chip_operations drivers_i2c_rx6110sa_ops = {
CHIP_NAME("RX6110 SA")
.enable_dev = rx6110sa_enable
};
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