src/drivers/i2c/pcf8523/pcf8523.c

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #include <commonlib/bsd/bcd.h>
   4 #include <console/console.h>
   5 #include <device/smbus.h>
   6 #include <version.h>
   7 #include "chip.h"
   8
   9 /* Set RTC date from coreboot build date. */
  10 static void pcf8523_set_build_date(struct device *dev)
  11 {
  12         smbus_write_byte(dev, YEAR_REG, coreboot_build_date.year);
  13         smbus_write_byte(dev, MONTH_REG, coreboot_build_date.month);
  14         smbus_write_byte(dev, WEEKDAY_REG, coreboot_build_date.weekday);
  15         smbus_write_byte(dev, DAY_REG, coreboot_build_date.day);
  16 }
  17
  18 /* Set RTC date from user defined date (available in e.g. device tree). */
  19 static void pcf8523_set_user_date(struct device *dev)
  20 {
  21         struct drivers_i2c_pcf8523_config *config = dev->chip_info;
  22         smbus_write_byte(dev, YEAR_REG, bin2bcd(config->user_year));
  23         smbus_write_byte(dev, MONTH_REG, bin2bcd(config->user_month));
  24         smbus_write_byte(dev, DAY_REG, bin2bcd(config->user_day));
  25         smbus_write_byte(dev, WEEKDAY_REG, bin2bcd(config->user_weekday));
  26 }
  27
  28 static void pcf8523_final(struct device *dev)
  29 {
  30         /* Read back current RTC date and time and print it to the console. */
  31         printk(BIOS_INFO, "%s: Current date %02d.%02d.%02d %02d:%02d:%02d\n",
  32                 dev->chip_ops->name,
  33                 bcd2bin(smbus_read_byte(dev, MONTH_REG)),
  34                 bcd2bin(smbus_read_byte(dev, DAY_REG)),
  35                 bcd2bin(smbus_read_byte(dev, YEAR_REG)),
  36                 bcd2bin(smbus_read_byte(dev, HOUR_REG)),
  37                 bcd2bin(smbus_read_byte(dev, MINUTE_REG)),
  38                 bcd2bin(smbus_read_byte(dev, SECOND_REG)) & ~OS_BIT);
  39 }
  40
  41 static void pcf8523_init(struct device *dev)
  42 {
  43         struct drivers_i2c_pcf8523_config *config = dev->chip_info;
  44         uint8_t reg = 0;
  45
  46         if (!(smbus_read_byte(dev, SECOND_REG) & OS_BIT)) {
  47                 /* Set control registers to a known good value even if no
  48                  * power loss event was recognized. There were issues with
  49                  * this RTC in the past where control registers were
  50                  * corrupted and OS bit was not set. */
  51                 reg = smbus_read_byte(dev, CTRL_REG_1);
  52                 reg &= ~(STOP_BIT | CAP_SEL);
  53                 reg |= ((!!config->cap_sel) << 7);
  54                 smbus_write_byte(dev, CTRL_REG_1, reg);
  55                 reg = smbus_read_byte(dev, CTRL_REG_3);
  56                 reg &= ~PM_MASK;
  57                 reg |= ((config->power_mode & 0x07) << 5);
  58                 smbus_write_byte(dev, CTRL_REG_3, reg);
  59                 reg = smbus_read_byte(dev, TMR_CLKOUT_REG);
  60                 reg &= ~COF_MASK;
  61                 reg |= ((config->cof_selection & 0x07) << 3);
  62                 smbus_write_byte(dev, TMR_CLKOUT_REG, reg);
  63                 return;
  64         }
  65
  66         /* Initialize the RTC fully only if a power-loss event was recognized.
  67          * In this case RTC will be set up with default date and time. */
  68         smbus_write_byte(dev, CTRL_REG_1, ((!!config->cap_sel) << 7) |
  69                                           ((!!config->second_int_en) << 2) |
  70                                           ((!!config->alarm_int_en) << 1) |
  71                                           (!!config->correction_int_en));
  72
  73         smbus_write_byte(dev, CTRL_REG_2, ((!!config->wdt_int_en) << 2) |
  74                                           ((!!config->tmrA_int_en) << 1) |
  75                                           (!!config->tmrB_int_en));
  76
  77         smbus_write_byte(dev, CTRL_REG_3, ((config->power_mode & 0x07) << 5) |
  78                                           ((!!config->bat_switch_int_en) << 1) |
  79                                           (!!config->bat_low_int_en));
  80
  81         smbus_write_byte(dev, OFFSET_REG, ((!!config->offset_mode) << 7) |
  82                                           (config->offset_val & 0x7f));
  83
  84         smbus_write_byte(dev, TMR_CLKOUT_REG, ((!!config->tmrA_int_mode) << 7) |
  85                                         ((!!config->tmrB_int_mode) << 6) |
  86                                         ((config->cof_selection & 0x07) << 3) |
  87                                         ((config->tmrA_mode & 0x03) << 1) |
  88                                         (!!config->tmrB_mode));
  89
  90         smbus_write_byte(dev, TMR_A_FREQ_REG, (config->tmrA_prescaler & 0x7));
  91
  92         smbus_write_byte(dev, TMR_B_FREQ_REG,  (config->tmrB_prescaler & 0x7) |
  93                                         ((config->tmrB_pulse_cfg & 0x7) << 4));
  94
  95         /* Before setting the clock stop oscillator. */
  96         reg = smbus_read_byte(dev, CTRL_REG_1);
  97         reg |= STOP_BIT;
  98         smbus_write_byte(dev, CTRL_REG_1, reg);
  99         if (config->set_user_date) {
 100                 /* Set user date defined in device tree. */
 101                 printk(BIOS_DEBUG, "%s: Set to user date\n",
 102                         dev->chip_ops->name);
 103                 pcf8523_set_user_date(dev);
 104         } else {
 105                 /* Set date from coreboot build. */
 106                 printk(BIOS_DEBUG, "%s: Set to coreboot build date\n",
 107                         dev->chip_ops->name);
 108                 pcf8523_set_build_date(dev);
 109         }
 110         /* Set time to 01:00:00 */
 111         smbus_write_byte(dev, HOUR_REG, 1);
 112         smbus_write_byte(dev, MINUTE_REG, 0);
 113         smbus_write_byte(dev, SECOND_REG, 0);
 114         /* Start oscillator again as the clock is set up now */
 115         reg &= ~STOP_BIT;
 116         smbus_write_byte(dev, CTRL_REG_1, reg);
 117 }
 118
 119 static struct device_operations pcf8523c_ops = {
 120         .read_resources         = noop_read_resources,
 121         .set_resources          = noop_set_resources,
 122         .init                   = pcf8523_init,
 123         .final                  = pcf8523_final
 124 };
 125
 126 static void pcf8523_enable(struct device *dev)
 127 {
 128         dev->ops = &pcf8523c_ops;
 129 }
 130
 131 struct chip_operations drivers_i2c_pcf8523_ops = {
 132         .name = "PCF8523",
 133         .enable_dev = pcf8523_enable
 134 };