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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_bus.h>
#include <device/device.h>
#include <version.h>
#include <console/console.h>
#include <bcd.h>
#include <timer.h>
#include "chip.h"
#include "rx6110sa.h"
/* 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)
{
i2c_writeb_at(dev, reg, val);
}
/* Function to read a register in the RTC. */
static uint8_t rx6110sa_read(struct device *dev, uint8_t reg)
{
return (uint8_t)i2c_readb_at(dev, reg);
}
/* 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, flags;
struct stopwatch sw;
/* Do a dummy read first as requested in the datasheet. */
rx6110sa_read(dev, SECOND_REG);
/* Check power loss status by reading the VLF-bit. */
flags = rx6110sa_read(dev, FLAG_REGISTER);
if (flags & VLF_BIT) {
/*
* Voltage low detected, perform RX6110 SA reset sequence as
* requested in the datasheet. The meaning of the registers 0x60
* and above is not documented in the datasheet, they have to be
* used as requested according to Epson.
*/
rx6110sa_write(dev, BATTERY_BACKUP_REG, 0x00);
rx6110sa_write(dev, CTRL_REG, 0x00);
rx6110sa_write(dev, CTRL_REG, TEST_BIT);
rx6110sa_write(dev, 0x60, 0xd3);
rx6110sa_write(dev, 0x66, 0x03);
rx6110sa_write(dev, 0x6b, 0x02);
rx6110sa_write(dev, 0x6b, 0x01);
/* According to the datasheet one have to wait for at least 2 ms
* before the VLF bit can be cleared in the flag register after
* this reset sequence. As the other registers are still
* accessible use the stopwatch to parallel the flow.
*/
stopwatch_init_msecs_expire(&sw, AFTER_RESET_DELAY_MS);
}
/*
* Set up important registers even if there was no power loss to make
* sure that the right mode is used as it directly influences the
* backup current consumption and therefore the backup time. These
* settings do not change current date and time and the RTC will not
* be stopped while the registers are set up.
*/
reg = (config->pmon_sampling & PMON_SAMPL_MASK) |
(!!config->bks_off << 2) | (!!config->bks_on << 3) |
(!!config->iocut_en << 4);
rx6110sa_write(dev, BATTERY_BACKUP_REG, reg);
/* Clear timer enable bit and set frequency of clock output. */
reg = rx6110sa_read(dev, EXTENSION_REG);
reg &= ~(FSEL_MASK);
reg |= ((config->cof_selection << 6) & FSEL_MASK);
if (config->timer_preset) {
/* Timer needs to be in stop mode prior to programming it. */
if (reg & TE_BIT) {
reg &= ~TE_BIT;
rx6110sa_write(dev, EXTENSION_REG, reg);
}
/* Program the timer preset value. */
rx6110sa_write(dev, TMR_COUNTER_0_REG,
config->timer_preset & 0xff);
rx6110sa_write(dev, TMR_COUNTER_1_REG,
(config->timer_preset >> 8) & 0xff);
/* Set Timer Enable bit and the timer clock value. */
reg &= ~TSEL_MASK;
reg |= ((!!config->timer_en << 4) |
(config->timer_clk & TSEL_MASK));
}
rx6110sa_write(dev, EXTENSION_REG, reg);
rx6110sa_write(dev, CTRL_REG, 0x00);
rx6110sa_write(dev, DIGITAL_REG, 0x00);
rx6110sa_write(dev, RESERVED_BIT_REG, RTC_INIT_VALUE);
reg = (!!config->enable_1hz_out << 4) |
(!!config->irq_output_pin << 2) |
(config->fout_output_pin & FOUT_OUTPUT_PIN_MASK);
rx6110sa_write(dev, IRQ_CONTROL_REG, reg);
/* If there was no power loss event no further steps are needed. */
if (!(flags & VLF_BIT))
return;
/* There was a power loss event, clear voltage low detect bit.
* Take the needed delay after a reset sequence into account before the
* VLF-bit can be cleared.
*/
while (!stopwatch_expired(&sw))
;
flags &= ~VLF_BIT;
rx6110sa_write(dev, FLAG_REGISTER, flags);
/* 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. */
reg = (!!config->timer_irq_en << 4) |
(config->timer_mode & TMR_MODE_MASK);
rx6110sa_write(dev, CTRL_REG, reg);
}
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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