// SPDX-License-Identifier: GPL-2.0-or-later /* * RTC client/driver for the Maxim/Dallas DS3232/DS3234 Real-Time Clock * * Copyright (C) 2009-2011 Freescale Semiconductor. * Author: Jack Lan * Copyright (C) 2008 MIMOMax Wireless Ltd. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #define DS3232_REG_SECONDS 0x00 #define DS3232_REG_MINUTES 0x01 #define DS3232_REG_HOURS 0x02 #define DS3232_REG_AMPM 0x02 #define DS3232_REG_DAY 0x03 #define DS3232_REG_DATE 0x04 #define DS3232_REG_MONTH 0x05 #define DS3232_REG_CENTURY 0x05 #define DS3232_REG_YEAR 0x06 #define DS3232_REG_ALARM1 0x07 /* Alarm 1 BASE */ #define DS3232_REG_ALARM2 0x0B /* Alarm 2 BASE */ #define DS3232_REG_CR 0x0E /* Control register */ # define DS3232_REG_CR_nEOSC 0x80 # define DS3232_REG_CR_INTCN 0x04 # define DS3232_REG_CR_A2IE 0x02 # define DS3232_REG_CR_A1IE 0x01 #define DS3232_REG_SR 0x0F /* control/status register */ # define DS3232_REG_SR_OSF 0x80 # define DS3232_REG_SR_BSY 0x04 # define DS3232_REG_SR_A2F 0x02 # define DS3232_REG_SR_A1F 0x01 #define DS3232_REG_TEMPERATURE 0x11 #define DS3232_REG_SRAM_START 0x14 #define DS3232_REG_SRAM_END 0xFF #define DS3232_REG_SRAM_SIZE 236 struct ds3232 { struct device *dev; struct regmap *regmap; int irq; struct rtc_device *rtc; bool suspended; }; static int ds3232_check_rtc_status(struct device *dev) { struct ds3232 *ds3232 = dev_get_drvdata(dev); int ret = 0; int control, stat; ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat); if (ret) return ret; if (stat & DS3232_REG_SR_OSF) dev_warn(dev, "oscillator discontinuity flagged, " "time unreliable\n"); stat &= ~(DS3232_REG_SR_OSF | DS3232_REG_SR_A1F | DS3232_REG_SR_A2F); ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat); if (ret) return ret; /* If the alarm is pending, clear it before requesting * the interrupt, so an interrupt event isn't reported * before everything is initialized. */ ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control); if (ret) return ret; control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE); control |= DS3232_REG_CR_INTCN; return regmap_write(ds3232->regmap, DS3232_REG_CR, control); } static int ds3232_read_time(struct device *dev, struct rtc_time *time) { struct ds3232 *ds3232 = dev_get_drvdata(dev); int ret; u8 buf[7]; unsigned int year, month, day, hour, minute, second; unsigned int week, twelve_hr, am_pm; unsigned int century, add_century = 0; ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_SECONDS, buf, 7); if (ret) return ret; second = buf[0]; minute = buf[1]; hour = buf[2]; week = buf[3]; day = buf[4]; month = buf[5]; year = buf[6]; /* Extract additional information for AM/PM and century */ twelve_hr = hour & 0x40; am_pm = hour & 0x20; century = month & 0x80; /* Write to rtc_time structure */ time->tm_sec = bcd2bin(second); time->tm_min = bcd2bin(minute); if (twelve_hr) { /* Convert to 24 hr */ if (am_pm) time->tm_hour = bcd2bin(hour & 0x1F) + 12; else time->tm_hour = bcd2bin(hour & 0x1F); } else { time->tm_hour = bcd2bin(hour); } /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */ time->tm_wday = bcd2bin(week) - 1; time->tm_mday = bcd2bin(day); /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */ time->tm_mon = bcd2bin(month & 0x7F) - 1; if (century) add_century = 100; time->tm_year = bcd2bin(year) + add_century; return 0; } static int ds3232_set_time(struct device *dev, struct rtc_time *time) { struct ds3232 *ds3232 = dev_get_drvdata(dev); u8 buf[7]; /* Extract time from rtc_time and load into ds3232*/ buf[0] = bin2bcd(time->tm_sec); buf[1] = bin2bcd(time->tm_min); buf[2] = bin2bcd(time->tm_hour); /* Day of the week in linux range is 0~6 while 1~7 in RTC chip */ buf[3] = bin2bcd(time->tm_wday + 1); buf[4] = bin2bcd(time->tm_mday); /* Date */ /* linux tm_mon range:0~11, while month range is 1~12 in RTC chip */ buf[5] = bin2bcd(time->tm_mon + 1); if (time->tm_year >= 100) { buf[5] |= 0x80; buf[6] = bin2bcd(time->tm_year - 100); } else { buf[6] = bin2bcd(time->tm_year); } return regmap_bulk_write(ds3232->regmap, DS3232_REG_SECONDS, buf, 7); } /* * DS3232 has two alarm, we only use alarm1 * According to linux specification, only support one-shot alarm * no periodic alarm mode */ static int ds3232_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) { struct ds3232 *ds3232 = dev_get_drvdata(dev); int control, stat; int ret; u8 buf[4]; ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat); if (ret) goto out; ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control); if (ret) goto out; ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_ALARM1, buf, 4); if (ret) goto out; alarm->time.tm_sec = bcd2bin(buf[0] & 0x7F); alarm->time.tm_min = bcd2bin(buf[1] & 0x7F); alarm->time.tm_hour = bcd2bin(buf[2] & 0x7F); alarm->time.tm_mday = bcd2bin(buf[3] & 0x7F); alarm->enabled = !!(control & DS3232_REG_CR_A1IE); alarm->pending = !!(stat & DS3232_REG_SR_A1F); ret = 0; out: return ret; } /* * linux rtc-module does not support wday alarm * and only 24h time mode supported indeed */ static int ds3232_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) { struct ds3232 *ds3232 = dev_get_drvdata(dev); int control, stat; int ret; u8 buf[4]; if (ds3232->irq <= 0) return -EINVAL; buf[0] = bin2bcd(alarm->time.tm_sec); buf[1] = bin2bcd(alarm->time.tm_min); buf[2] = bin2bcd(alarm->time.tm_hour); buf[3] = bin2bcd(alarm->time.tm_mday); /* clear alarm interrupt enable bit */ ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control); if (ret) goto out; control &= ~(DS3232_REG_CR_A1IE | DS3232_REG_CR_A2IE); ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control); if (ret) goto out; /* clear any pending alarm flag */ ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat); if (ret) goto out; stat &= ~(DS3232_REG_SR_A1F | DS3232_REG_SR_A2F); ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat); if (ret) goto out; ret = regmap_bulk_write(ds3232->regmap, DS3232_REG_ALARM1, buf, 4); if (ret) goto out; if (alarm->enabled) { control |= DS3232_REG_CR_A1IE; ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control); } out: return ret; } static int ds3232_update_alarm(struct device *dev, unsigned int enabled) { struct ds3232 *ds3232 = dev_get_drvdata(dev); int control; int ret; ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control); if (ret) return ret; if (enabled) /* enable alarm1 interrupt */ control |= DS3232_REG_CR_A1IE; else /* disable alarm1 interrupt */ control &= ~(DS3232_REG_CR_A1IE); ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control); return ret; } /* * Temperature sensor support for ds3232/ds3234 devices. * A user-initiated temperature conversion is not started by this function, * so the temperature is updated once every 64 seconds. */ static int ds3232_hwmon_read_temp(struct device *dev, long int *mC) { struct ds3232 *ds3232 = dev_get_drvdata(dev); u8 temp_buf[2]; s16 temp; int ret; ret = regmap_bulk_read(ds3232->regmap, DS3232_REG_TEMPERATURE, temp_buf, sizeof(temp_buf)); if (ret < 0) return ret; /* * Temperature is represented as a 10-bit code with a resolution of * 0.25 degree celsius and encoded in two's complement format. */ temp = (temp_buf[0] << 8) | temp_buf[1]; temp >>= 6; *mC = temp * 250; return 0; } static umode_t ds3232_hwmon_is_visible(const void *data, enum hwmon_sensor_types type, u32 attr, int channel) { if (type != hwmon_temp) return 0; switch (attr) { case hwmon_temp_input: return 0444; default: return 0; } } static int ds3232_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *temp) { int err; switch (attr) { case hwmon_temp_input: err = ds3232_hwmon_read_temp(dev, temp); break; default: err = -EOPNOTSUPP; break; } return err; } static u32 ds3232_hwmon_chip_config[] = { HWMON_C_REGISTER_TZ, 0 }; static const struct hwmon_channel_info ds3232_hwmon_chip = { .type = hwmon_chip, .config = ds3232_hwmon_chip_config, }; static u32 ds3232_hwmon_temp_config[] = { HWMON_T_INPUT, 0 }; static const struct hwmon_channel_info ds3232_hwmon_temp = { .type = hwmon_temp, .config = ds3232_hwmon_temp_config, }; static const struct hwmon_channel_info * const ds3232_hwmon_info[] = { &ds3232_hwmon_chip, &ds3232_hwmon_temp, NULL }; static const struct hwmon_ops ds3232_hwmon_hwmon_ops = { .is_visible = ds3232_hwmon_is_visible, .read = ds3232_hwmon_read, }; static const struct hwmon_chip_info ds3232_hwmon_chip_info = { .ops = &ds3232_hwmon_hwmon_ops, .info = ds3232_hwmon_info, }; static void ds3232_hwmon_register(struct device *dev, const char *name) { struct ds3232 *ds3232 = dev_get_drvdata(dev); struct device *hwmon_dev; if (!IS_ENABLED(CONFIG_RTC_DRV_DS3232_HWMON)) return; hwmon_dev = devm_hwmon_device_register_with_info(dev, name, ds3232, &ds3232_hwmon_chip_info, NULL); if (IS_ERR(hwmon_dev)) { dev_err(dev, "unable to register hwmon device %ld\n", PTR_ERR(hwmon_dev)); } } static int ds3232_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct ds3232 *ds3232 = dev_get_drvdata(dev); if (ds3232->irq <= 0) return -EINVAL; return ds3232_update_alarm(dev, enabled); } static irqreturn_t ds3232_irq(int irq, void *dev_id) { struct device *dev = dev_id; struct ds3232 *ds3232 = dev_get_drvdata(dev); int ret; int stat, control; rtc_lock(ds3232->rtc); ret = regmap_read(ds3232->regmap, DS3232_REG_SR, &stat); if (ret) goto unlock; if (stat & DS3232_REG_SR_A1F) { ret = regmap_read(ds3232->regmap, DS3232_REG_CR, &control); if (ret) { dev_warn(ds3232->dev, "Read Control Register error %d\n", ret); } else { /* disable alarm1 interrupt */ control &= ~(DS3232_REG_CR_A1IE); ret = regmap_write(ds3232->regmap, DS3232_REG_CR, control); if (ret) { dev_warn(ds3232->dev, "Write Control Register error %d\n", ret); goto unlock; } /* clear the alarm pend flag */ stat &= ~DS3232_REG_SR_A1F; ret = regmap_write(ds3232->regmap, DS3232_REG_SR, stat); if (ret) { dev_warn(ds3232->dev, "Write Status Register error %d\n", ret); goto unlock; } rtc_update_irq(ds3232->rtc, 1, RTC_AF | RTC_IRQF); } } unlock: rtc_unlock(ds3232->rtc); return IRQ_HANDLED; } static const struct rtc_class_ops ds3232_rtc_ops = { .read_time = ds3232_read_time, .set_time = ds3232_set_time, .read_alarm = ds3232_read_alarm, .set_alarm = ds3232_set_alarm, .alarm_irq_enable = ds3232_alarm_irq_enable, }; static int ds3232_nvmem_read(void *priv, unsigned int offset, void *val, size_t bytes) { struct regmap *ds3232_regmap = (struct regmap *)priv; return regmap_bulk_read(ds3232_regmap, DS3232_REG_SRAM_START + offset, val, bytes); } static int ds3232_nvmem_write(void *priv, unsigned int offset, void *val, size_t bytes) { struct regmap *ds3232_regmap = (struct regmap *)priv; return regmap_bulk_write(ds3232_regmap, DS3232_REG_SRAM_START + offset, val, bytes); } static int ds3232_probe(struct device *dev, struct regmap *regmap, int irq, const char *name) { struct ds3232 *ds3232; int ret; struct nvmem_config nvmem_cfg = { .name = "ds3232_sram", .stride = 1, .size = DS3232_REG_SRAM_SIZE, .word_size = 1, .reg_read = ds3232_nvmem_read, .reg_write = ds3232_nvmem_write, .priv = regmap, .type = NVMEM_TYPE_BATTERY_BACKED }; ds3232 = devm_kzalloc(dev, sizeof(*ds3232), GFP_KERNEL); if (!ds3232) return -ENOMEM; ds3232->regmap = regmap; ds3232->irq = irq; ds3232->dev = dev; dev_set_drvdata(dev, ds3232); ret = ds3232_check_rtc_status(dev); if (ret) return ret; if (ds3232->irq > 0) device_init_wakeup(dev, 1); ds3232_hwmon_register(dev, name); ds3232->rtc = devm_rtc_device_register(dev, name, &ds3232_rtc_ops, THIS_MODULE); if (IS_ERR(ds3232->rtc)) return PTR_ERR(ds3232->rtc); ret = devm_rtc_nvmem_register(ds3232->rtc, &nvmem_cfg); if(ret) return ret; if (ds3232->irq > 0) { ret = devm_request_threaded_irq(dev, ds3232->irq, NULL, ds3232_irq, IRQF_SHARED | IRQF_ONESHOT, name, dev); if (ret) { device_set_wakeup_capable(dev, 0); ds3232->irq = 0; dev_err(dev, "unable to request IRQ\n"); } } return 0; } #ifdef CONFIG_PM_SLEEP static int ds3232_suspend(struct device *dev) { struct ds3232 *ds3232 = dev_get_drvdata(dev); if (device_may_wakeup(dev)) { if (enable_irq_wake(ds3232->irq)) dev_warn_once(dev, "Cannot set wakeup source\n"); } return 0; } static int ds3232_resume(struct device *dev) { struct ds3232 *ds3232 = dev_get_drvdata(dev); if (device_may_wakeup(dev)) disable_irq_wake(ds3232->irq); return 0; } #endif static const struct dev_pm_ops ds3232_pm_ops = { SET_SYSTEM_SLEEP_PM_OPS(ds3232_suspend, ds3232_resume) }; #if IS_ENABLED(CONFIG_I2C) static int ds3232_i2c_probe(struct i2c_client *client) { struct regmap *regmap; static const struct regmap_config config = { .reg_bits = 8, .val_bits = 8, .max_register = DS3232_REG_SRAM_END, }; regmap = devm_regmap_init_i2c(client, &config); if (IS_ERR(regmap)) { dev_err(&client->dev, "%s: regmap allocation failed: %ld\n", __func__, PTR_ERR(regmap)); return PTR_ERR(regmap); } return ds3232_probe(&client->dev, regmap, client->irq, client->name); } static const struct i2c_device_id ds3232_id[] = { { "ds3232", 0 }, { } }; MODULE_DEVICE_TABLE(i2c, ds3232_id); static const __maybe_unused struct of_device_id ds3232_of_match[] = { { .compatible = "dallas,ds3232" }, { } }; MODULE_DEVICE_TABLE(of, ds3232_of_match); static struct i2c_driver ds3232_driver = { .driver = { .name = "rtc-ds3232", .of_match_table = of_match_ptr(ds3232_of_match), .pm = &ds3232_pm_ops, }, .probe = ds3232_i2c_probe, .id_table = ds3232_id, }; static int ds3232_register_driver(void) { return i2c_add_driver(&ds3232_driver); } static void ds3232_unregister_driver(void) { i2c_del_driver(&ds3232_driver); } #else static int ds3232_register_driver(void) { return 0; } static void ds3232_unregister_driver(void) { } #endif #if IS_ENABLED(CONFIG_SPI_MASTER) static int ds3234_probe(struct spi_device *spi) { int res; unsigned int tmp; static const struct regmap_config config = { .reg_bits = 8, .val_bits = 8, .max_register = DS3232_REG_SRAM_END, .write_flag_mask = 0x80, }; struct regmap *regmap; regmap = devm_regmap_init_spi(spi, &config); if (IS_ERR(regmap)) { dev_err(&spi->dev, "%s: regmap allocation failed: %ld\n", __func__, PTR_ERR(regmap)); return PTR_ERR(regmap); } spi->mode = SPI_MODE_3; spi->bits_per_word = 8; spi_setup(spi); res = regmap_read(regmap, DS3232_REG_SECONDS, &tmp); if (res) return res; /* Control settings * * CONTROL_REG * BIT 7 6 5 4 3 2 1 0 * EOSC BBSQW CONV RS2 RS1 INTCN A2IE A1IE * * 0 0 0 1 1 1 0 0 * * CONTROL_STAT_REG * BIT 7 6 5 4 3 2 1 0 * OSF BB32kHz CRATE1 CRATE0 EN32kHz BSY A2F A1F * * 1 0 0 0 1 0 0 0 */ res = regmap_read(regmap, DS3232_REG_CR, &tmp); if (res) return res; res = regmap_write(regmap, DS3232_REG_CR, tmp & 0x1c); if (res) return res; res = regmap_read(regmap, DS3232_REG_SR, &tmp); if (res) return res; res = regmap_write(regmap, DS3232_REG_SR, tmp & 0x88); if (res) return res; /* Print our settings */ res = regmap_read(regmap, DS3232_REG_CR, &tmp); if (res) return res; dev_info(&spi->dev, "Control Reg: 0x%02x\n", tmp); res = regmap_read(regmap, DS3232_REG_SR, &tmp); if (res) return res; dev_info(&spi->dev, "Ctrl/Stat Reg: 0x%02x\n", tmp); return ds3232_probe(&spi->dev, regmap, spi->irq, "ds3234"); } static const __maybe_unused struct of_device_id ds3234_of_match[] = { { .compatible = "dallas,ds3234" }, { } }; MODULE_DEVICE_TABLE(of, ds3234_of_match); static struct spi_driver ds3234_driver = { .driver = { .name = "ds3234", .of_match_table = of_match_ptr(ds3234_of_match), }, .probe = ds3234_probe, }; static int ds3234_register_driver(void) { return spi_register_driver(&ds3234_driver); } static void ds3234_unregister_driver(void) { spi_unregister_driver(&ds3234_driver); } #else static int ds3234_register_driver(void) { return 0; } static void ds3234_unregister_driver(void) { } #endif static int __init ds323x_init(void) { int ret; ret = ds3232_register_driver(); if (ret) { pr_err("Failed to register ds3232 driver: %d\n", ret); return ret; } ret = ds3234_register_driver(); if (ret) { pr_err("Failed to register ds3234 driver: %d\n", ret); ds3232_unregister_driver(); } return ret; } module_init(ds323x_init) static void __exit ds323x_exit(void) { ds3234_unregister_driver(); ds3232_unregister_driver(); } module_exit(ds323x_exit) MODULE_AUTHOR("Srikanth Srinivasan "); MODULE_AUTHOR("Dennis Aberilla "); MODULE_DESCRIPTION("Maxim/Dallas DS3232/DS3234 RTC Driver"); MODULE_LICENSE("GPL"); MODULE_ALIAS("spi:ds3234");