diff options
Diffstat (limited to 'src/drivers/i2c/pcf8523/pcf8523.c')
| -rw-r--r-- | src/drivers/i2c/pcf8523/pcf8523.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/src/drivers/i2c/pcf8523/pcf8523.c b/src/drivers/i2c/pcf8523/pcf8523.c new file mode 100644 index 0000000000..eb0bf25123 --- /dev/null +++ b/src/drivers/i2c/pcf8523/pcf8523.c @@ -0,0 +1,148 @@ +/* + * This file is part of the coreboot project. + * + * Copyright 2016 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/smbus.h> +#include <version.h> +#include <console/console.h> +#include <bcd.h> +#include "chip.h" + +/* Set RTC date from coreboot build date. */ +static void pcf8523_set_build_date(struct device *dev) +{ + smbus_write_byte(dev, YEAR_REG, coreboot_build_date.year); + smbus_write_byte(dev, MONTH_REG, coreboot_build_date.month); + smbus_write_byte(dev, WEEKDAY_REG, coreboot_build_date.weekday); + smbus_write_byte(dev, DAY_REG, coreboot_build_date.day); +} + +/* Set RTC date from user defined date (available in e.g. device tree). */ +static void pcf8523_set_user_date(struct device *dev) +{ + struct drivers_i2c_pcf8523_config *config = dev->chip_info; + smbus_write_byte(dev, YEAR_REG, bin2bcd(config->user_year)); + smbus_write_byte(dev, MONTH_REG, bin2bcd(config->user_month)); + smbus_write_byte(dev, DAY_REG, bin2bcd(config->user_day)); + smbus_write_byte(dev, WEEKDAY_REG, bin2bcd(config->user_weekday)); +} + +static void pcf8523_final(struct device *dev) +{ + /* Read back current RTC date and time and print it to the console. */ + printk(BIOS_INFO, "%s: Current date %02d.%02d.%02d %02d:%02d:%02d\n", + dev->chip_ops->name, + bcd2bin(smbus_read_byte(dev, MONTH_REG)), + bcd2bin(smbus_read_byte(dev, DAY_REG)), + bcd2bin(smbus_read_byte(dev, YEAR_REG)), + bcd2bin(smbus_read_byte(dev, HOUR_REG)), + bcd2bin(smbus_read_byte(dev, MINUTE_REG)), + bcd2bin(smbus_read_byte(dev, SECOND_REG)) & ~OS_BIT); +} + +static void pcf8523_init(struct device *dev) +{ + struct drivers_i2c_pcf8523_config *config = dev->chip_info; + uint8_t reg = 0; + + if (!(smbus_read_byte(dev, SECOND_REG) & OS_BIT)) { + /* Set control registers to a known good value even if no + * power loss event was recognized. There were issues with + * this RTC in the past where control registers were + * corrupted and OS bit was not set. */ + reg = smbus_read_byte(dev, CTRL_REG_1); + reg &= ~(STOP_BIT | CAP_SEL); + reg |= config->cap_sel; + smbus_write_byte(dev, CTRL_REG_1, reg); + reg = smbus_read_byte(dev, CTRL_REG_3); + reg &= ~PM_MASK; + reg |= config->power_mode; + smbus_write_byte(dev, CTRL_REG_3, reg); + reg = smbus_read_byte(dev, TMR_CLKOUT_REG); + reg &= ~COF_MASK; + reg |= config->cof_selection; + smbus_write_byte(dev, TMR_CLKOUT_REG, reg); + return; + } + + /* Initialize the RTC fully only if a power-loss event was recognized. + * In this case RTC will be set up with default date and time. */ + smbus_write_byte(dev, CTRL_REG_1, ((!!config->cap_sel) << 7) | + ((!!config->second_int_en) << 2) | + ((!!config->alarm_int_en) << 1) | + (!!config->correction_int_en)); + + smbus_write_byte(dev, CTRL_REG_2, ((!!config->wdt_int_en) << 2) | + ((!!config->tmrA_int_en) << 1) | + (!!config->tmrB_int_en)); + + smbus_write_byte(dev, CTRL_REG_3, ((config->power_mode & 0x03) << 5) | + ((!!config->bat_switch_int_en) << 1) | + (!!config->bat_low_int_en)); + + smbus_write_byte(dev, OFFSET_REG, ((!!config->offset_mode) << 7) | + (config->offset_val & 0x7f)); + + smbus_write_byte(dev, TMR_CLKOUT_REG, ((!!config->tmrA_int_mode) << 7) | + ((!!config->tmrB_int_mode) << 6) | + ((config->cof_selection & 0x38) << 3) | + ((config->tmrA_mode & 0x03) << 1) | + (!!config->tmrB_mode)); + + smbus_write_byte(dev, TMR_A_FREQ_REG, (config->tmrA_prescaler & 0x7)); + + smbus_write_byte(dev, TMR_B_FREQ_REG, (config->tmrB_prescaler & 0x7) | + ((config->tmrB_pulse_cfg & 0x7) << 4)); + + /* Before setting the clock stop oscillator. */ + reg = smbus_read_byte(dev, CTRL_REG_1); + reg |= STOP_BIT; + smbus_write_byte(dev, CTRL_REG_1, reg); + 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); + pcf8523_set_user_date(dev); + } else { + /* Set date from coreboot build. */ + printk(BIOS_DEBUG, "%s: Set to coreboot build date\n", + dev->chip_ops->name); + pcf8523_set_build_date(dev); + } + /* Set time to 01:00:00 */ + smbus_write_byte(dev, HOUR_REG, 1); + smbus_write_byte(dev, MINUTE_REG, 0); + smbus_write_byte(dev, SECOND_REG, 0); + /* Start oscillator again as the clock is set up now */ + reg &= ~STOP_BIT; + smbus_write_byte(dev, CTRL_REG_1, reg); +} + +static struct device_operations pcf8523c_ops = { + .read_resources = DEVICE_NOOP, + .set_resources = DEVICE_NOOP, + .enable_resources = DEVICE_NOOP, + .init = pcf8523_init, + .final = pcf8523_final +}; + +static void pcf8523_enable(struct device *dev) +{ + dev->ops = &pcf8523c_ops; +} + +struct chip_operations drivers_i2c_pcf8523_ops = { + CHIP_NAME("PCF8523") + .enable_dev = pcf8523_enable +}; |