hekate/bootloader/rtc/max77620-rtc.c

/*
 * PMIC Real Time Clock driver for Nintendo Switch's MAX77620-RTC
 *
 * Copyright (c) 2018 CTCaer
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "max77620-rtc.h"
#include "../soc/i2c.h"
#include "../utils/util.h"

void max77620_rtc_get_time(rtc_time_t *time)
{
	u8 val = 0;

	// Update RTC regs from RTC clock.
	i2c_send_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_RTC_UPDATE0_REG, MAX77620_RTC_READ_UPDATE);

	// Get control reg config.
	val = i2c_recv_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_RTC_CONTROL_REG);
	// TODO: Check for binary format also?

	// Get time.
	time->sec  = i2c_recv_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_RTC_SEC_REG) & 0x7F;
	time->min  = i2c_recv_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_RTC_MIN_REG) & 0x7F;

	time->hour = i2c_recv_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_RTC_HOUR_REG) & 0x1F;

	if (!(val & MAX77620_RTC_24H) && time->hour & MAX77620_RTC_HOUR_PM_MASK)
		time->hour = (time->hour & 0xF) + 12;

	// Get day of week. 1: Monday to 7: Sunday.
	time->weekday = 0;
	val = i2c_recv_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_RTC_WEEKDAY_REG);
	for (int i = 0; i < 8; i++)
	{
		time->weekday++;
		if (val & 1)
			break;
		val >>= 1;
	}

	// Get date.
	time->day  = i2c_recv_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_RTC_DATE_REG) & 0x1f;
	time->month = (i2c_recv_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_RTC_MONTH_REG) & 0xF) - 1;
	time->year  = (i2c_recv_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_RTC_YEAR_REG) & 0x7F) + 2000;
}

void max77620_rtc_stop_alarm()
{
	u8 val = 0;

	// Update RTC regs from RTC clock.
	i2c_send_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_RTC_UPDATE0_REG, MAX77620_RTC_READ_UPDATE);

	// Stop alarm for both ALARM1 and ALARM2. Horizon uses ALARM2.
	for (int i = 0; i < (MAX77620_RTC_NR_TIME_REGS * 2); i++)
	{
		val = i2c_recv_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_ALARM1_SEC_REG + i);
		val &= ~MAX77620_RTC_ALARM_EN_MASK;
		i2c_send_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_ALARM1_SEC_REG + i, val);
	}

	// Update RTC clock from RTC regs.
	i2c_send_byte(I2C_5, MAX77620_RTC_I2C_ADDR, MAX77620_RTC_UPDATE0_REG, MAX77620_RTC_WRITE_UPDATE);
}