/* * This file is part of the coreboot project. * * Copyright (C) 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 #include #include #include #include #include #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. */ stopwatch_wait_until_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 };