// SPDX-License-Identifier: GPL-2.0 /* * RTC driver for the Micro Crystal RV8803 * * Copyright (C) 2015 Micro Crystal SA * Alexandre Belloni * */ #include #include #include #include #include #include #include #include #include #include #include #define RV8803_I2C_TRY_COUNT 4 #define RV8803_SEC 0x00 #define RV8803_MIN 0x01 #define RV8803_HOUR 0x02 #define RV8803_WEEK 0x03 #define RV8803_DAY 0x04 #define RV8803_MONTH 0x05 #define RV8803_YEAR 0x06 #define RV8803_RAM 0x07 #define RV8803_ALARM_MIN 0x08 #define RV8803_ALARM_HOUR 0x09 #define RV8803_ALARM_WEEK_OR_DAY 0x0A #define RV8803_EXT 0x0D #define RV8803_FLAG 0x0E #define RV8803_CTRL 0x0F #define RV8803_OSC_OFFSET 0x2C #define RV8803_EXT_WADA BIT(6) #define RV8803_FLAG_V1F BIT(0) #define RV8803_FLAG_V2F BIT(1) #define RV8803_FLAG_AF BIT(3) #define RV8803_FLAG_TF BIT(4) #define RV8803_FLAG_UF BIT(5) #define RV8803_CTRL_RESET BIT(0) #define RV8803_CTRL_EIE BIT(2) #define RV8803_CTRL_AIE BIT(3) #define RV8803_CTRL_TIE BIT(4) #define RV8803_CTRL_UIE BIT(5) #define RX8803_CTRL_CSEL GENMASK(7, 6) #define RX8900_BACKUP_CTRL 0x18 #define RX8900_FLAG_SWOFF BIT(2) #define RX8900_FLAG_VDETOFF BIT(3) enum rv8803_type { rv_8803, rx_8803, rx_8804, rx_8900 }; struct rv8803_data { struct i2c_client *client; struct rtc_device *rtc; struct mutex flags_lock; u8 ctrl; u8 backup; u8 alarm_invalid:1; enum rv8803_type type; }; static int rv8803_read_reg(const struct i2c_client *client, u8 reg) { int try = RV8803_I2C_TRY_COUNT; s32 ret; /* * There is a 61µs window during which the RTC does not acknowledge I2C * transfers. In that case, ensure that there are multiple attempts. */ do ret = i2c_smbus_read_byte_data(client, reg); while ((ret == -ENXIO || ret == -EIO) && --try); if (ret < 0) dev_err(&client->dev, "Unable to read register 0x%02x\n", reg); return ret; } static int rv8803_read_regs(const struct i2c_client *client, u8 reg, u8 count, u8 *values) { int try = RV8803_I2C_TRY_COUNT; s32 ret; do ret = i2c_smbus_read_i2c_block_data(client, reg, count, values); while ((ret == -ENXIO || ret == -EIO) && --try); if (ret != count) { dev_err(&client->dev, "Unable to read registers 0x%02x..0x%02x\n", reg, reg + count - 1); return ret < 0 ? ret : -EIO; } return 0; } static int rv8803_write_reg(const struct i2c_client *client, u8 reg, u8 value) { int try = RV8803_I2C_TRY_COUNT; s32 ret; do ret = i2c_smbus_write_byte_data(client, reg, value); while ((ret == -ENXIO || ret == -EIO) && --try); if (ret) dev_err(&client->dev, "Unable to write register 0x%02x\n", reg); return ret; } static int rv8803_write_regs(const struct i2c_client *client, u8 reg, u8 count, const u8 *values) { int try = RV8803_I2C_TRY_COUNT; s32 ret; do ret = i2c_smbus_write_i2c_block_data(client, reg, count, values); while ((ret == -ENXIO || ret == -EIO) && --try); if (ret) dev_err(&client->dev, "Unable to write registers 0x%02x..0x%02x\n", reg, reg + count - 1); return ret; } static int rv8803_regs_init(struct rv8803_data *rv8803) { int ret; ret = rv8803_write_reg(rv8803->client, RV8803_OSC_OFFSET, 0x00); if (ret) return ret; ret = rv8803_write_reg(rv8803->client, RV8803_CTRL, FIELD_PREP(RX8803_CTRL_CSEL, 1)); /* 2s */ if (ret) return ret; ret = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3, (u8[]){ 0, 0, 0 }); if (ret) return ret; return rv8803_write_reg(rv8803->client, RV8803_RAM, 0x00); } static int rv8803_regs_configure(struct rv8803_data *rv8803); static int rv8803_regs_reset(struct rv8803_data *rv8803, bool full) { /* * The RV-8803 resets all registers to POR defaults after voltage-loss, * the Epson RTCs don't, so we manually reset the remainder here. */ if (full || rv8803->type == rx_8803 || rv8803->type == rx_8900) { int ret = rv8803_regs_init(rv8803); if (ret) return ret; } return rv8803_regs_configure(rv8803); } static irqreturn_t rv8803_handle_irq(int irq, void *dev_id) { struct i2c_client *client = dev_id; struct rv8803_data *rv8803 = i2c_get_clientdata(client); unsigned long events = 0; int flags; mutex_lock(&rv8803->flags_lock); flags = rv8803_read_reg(client, RV8803_FLAG); if (flags <= 0) { mutex_unlock(&rv8803->flags_lock); return IRQ_NONE; } if (flags & RV8803_FLAG_V1F) dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n"); if (flags & RV8803_FLAG_V2F) dev_warn(&client->dev, "Voltage low, data loss detected.\n"); if (flags & RV8803_FLAG_TF) { flags &= ~RV8803_FLAG_TF; rv8803->ctrl &= ~RV8803_CTRL_TIE; events |= RTC_PF; } if (flags & RV8803_FLAG_AF) { flags &= ~RV8803_FLAG_AF; rv8803->ctrl &= ~RV8803_CTRL_AIE; events |= RTC_AF; } if (flags & RV8803_FLAG_UF) { flags &= ~RV8803_FLAG_UF; rv8803->ctrl &= ~RV8803_CTRL_UIE; events |= RTC_UF; } if (events) { rtc_update_irq(rv8803->rtc, 1, events); rv8803_write_reg(client, RV8803_FLAG, flags); rv8803_write_reg(rv8803->client, RV8803_CTRL, rv8803->ctrl); } mutex_unlock(&rv8803->flags_lock); return IRQ_HANDLED; } static int rv8803_get_time(struct device *dev, struct rtc_time *tm) { struct rv8803_data *rv8803 = dev_get_drvdata(dev); u8 date1[7]; u8 date2[7]; u8 *date = date1; int ret, flags; if (rv8803->alarm_invalid) { dev_warn(dev, "Corruption detected, data may be invalid.\n"); return -EINVAL; } flags = rv8803_read_reg(rv8803->client, RV8803_FLAG); if (flags < 0) return flags; if (flags & RV8803_FLAG_V2F) { dev_warn(dev, "Voltage low, data is invalid.\n"); return -EINVAL; } ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date); if (ret) return ret; if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) { ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date2); if (ret) return ret; if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59)) date = date2; } tm->tm_sec = bcd2bin(date[RV8803_SEC] & 0x7f); tm->tm_min = bcd2bin(date[RV8803_MIN] & 0x7f); tm->tm_hour = bcd2bin(date[RV8803_HOUR] & 0x3f); tm->tm_wday = ilog2(date[RV8803_WEEK] & 0x7f); tm->tm_mday = bcd2bin(date[RV8803_DAY] & 0x3f); tm->tm_mon = bcd2bin(date[RV8803_MONTH] & 0x1f) - 1; tm->tm_year = bcd2bin(date[RV8803_YEAR]) + 100; return 0; } static int rv8803_set_time(struct device *dev, struct rtc_time *tm) { struct rv8803_data *rv8803 = dev_get_drvdata(dev); u8 date[7]; int ctrl, flags, ret; ctrl = rv8803_read_reg(rv8803->client, RV8803_CTRL); if (ctrl < 0) return ctrl; /* Stop the clock */ ret = rv8803_write_reg(rv8803->client, RV8803_CTRL, ctrl | RV8803_CTRL_RESET); if (ret) return ret; date[RV8803_SEC] = bin2bcd(tm->tm_sec); date[RV8803_MIN] = bin2bcd(tm->tm_min); date[RV8803_HOUR] = bin2bcd(tm->tm_hour); date[RV8803_WEEK] = 1 << (tm->tm_wday); date[RV8803_DAY] = bin2bcd(tm->tm_mday); date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1); date[RV8803_YEAR] = bin2bcd(tm->tm_year - 100); ret = rv8803_write_regs(rv8803->client, RV8803_SEC, 7, date); if (ret) return ret; /* Restart the clock */ ret = rv8803_write_reg(rv8803->client, RV8803_CTRL, ctrl & ~RV8803_CTRL_RESET); if (ret) return ret; mutex_lock(&rv8803->flags_lock); flags = rv8803_read_reg(rv8803->client, RV8803_FLAG); if (flags < 0) { mutex_unlock(&rv8803->flags_lock); return flags; } if ((flags & RV8803_FLAG_V2F) || rv8803->alarm_invalid) { /* * If we sense corruption in the alarm registers, but see no * voltage loss flag, we can't rely on other registers having * sensible values. Reset them fully. */ ret = rv8803_regs_reset(rv8803, rv8803->alarm_invalid); if (ret) { mutex_unlock(&rv8803->flags_lock); return ret; } rv8803->alarm_invalid = false; } ret = rv8803_write_reg(rv8803->client, RV8803_FLAG, flags & ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F)); mutex_unlock(&rv8803->flags_lock); return ret; } static int rv8803_get_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct rv8803_data *rv8803 = dev_get_drvdata(dev); struct i2c_client *client = rv8803->client; u8 alarmvals[3]; int flags, ret; ret = rv8803_read_regs(client, RV8803_ALARM_MIN, 3, alarmvals); if (ret) return ret; flags = rv8803_read_reg(client, RV8803_FLAG); if (flags < 0) return flags; alarmvals[0] &= 0x7f; alarmvals[1] &= 0x3f; alarmvals[2] &= 0x3f; if (!bcd_is_valid(alarmvals[0]) || !bcd_is_valid(alarmvals[1]) || !bcd_is_valid(alarmvals[2])) goto err_invalid; alrm->time.tm_sec = 0; alrm->time.tm_min = bcd2bin(alarmvals[0]); alrm->time.tm_hour = bcd2bin(alarmvals[1]); alrm->time.tm_mday = bcd2bin(alarmvals[2]); alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE); alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled; if ((unsigned int)alrm->time.tm_mday > 31 || (unsigned int)alrm->time.tm_hour >= 24 || (unsigned int)alrm->time.tm_min >= 60) goto err_invalid; return 0; err_invalid: rv8803->alarm_invalid = true; return -EINVAL; } static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) { struct i2c_client *client = to_i2c_client(dev); struct rv8803_data *rv8803 = dev_get_drvdata(dev); u8 alarmvals[3]; u8 ctrl[2]; int ret, err; /* The alarm has no seconds, round up to nearest minute */ if (alrm->time.tm_sec) { time64_t alarm_time = rtc_tm_to_time64(&alrm->time); alarm_time += 60 - alrm->time.tm_sec; rtc_time64_to_tm(alarm_time, &alrm->time); } mutex_lock(&rv8803->flags_lock); ret = rv8803_read_regs(client, RV8803_FLAG, 2, ctrl); if (ret) { mutex_unlock(&rv8803->flags_lock); return ret; } alarmvals[0] = bin2bcd(alrm->time.tm_min); alarmvals[1] = bin2bcd(alrm->time.tm_hour); alarmvals[2] = bin2bcd(alrm->time.tm_mday); if (rv8803->ctrl & (RV8803_CTRL_AIE | RV8803_CTRL_UIE)) { rv8803->ctrl &= ~(RV8803_CTRL_AIE | RV8803_CTRL_UIE); err = rv8803_write_reg(rv8803->client, RV8803_CTRL, rv8803->ctrl); if (err) { mutex_unlock(&rv8803->flags_lock); return err; } } ctrl[0] &= ~RV8803_FLAG_AF; err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[0]); mutex_unlock(&rv8803->flags_lock); if (err) return err; err = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3, alarmvals); if (err) return err; if (alrm->enabled) { if (rv8803->rtc->uie_rtctimer.enabled) rv8803->ctrl |= RV8803_CTRL_UIE; if (rv8803->rtc->aie_timer.enabled) rv8803->ctrl |= RV8803_CTRL_AIE; err = rv8803_write_reg(rv8803->client, RV8803_CTRL, rv8803->ctrl); if (err) return err; } return 0; } static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled) { struct i2c_client *client = to_i2c_client(dev); struct rv8803_data *rv8803 = dev_get_drvdata(dev); int ctrl, flags, err; ctrl = rv8803->ctrl; if (enabled) { if (rv8803->rtc->uie_rtctimer.enabled) ctrl |= RV8803_CTRL_UIE; if (rv8803->rtc->aie_timer.enabled) ctrl |= RV8803_CTRL_AIE; } else { if (!rv8803->rtc->uie_rtctimer.enabled) ctrl &= ~RV8803_CTRL_UIE; if (!rv8803->rtc->aie_timer.enabled) ctrl &= ~RV8803_CTRL_AIE; } mutex_lock(&rv8803->flags_lock); flags = rv8803_read_reg(client, RV8803_FLAG); if (flags < 0) { mutex_unlock(&rv8803->flags_lock); return flags; } flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF); err = rv8803_write_reg(client, RV8803_FLAG, flags); mutex_unlock(&rv8803->flags_lock); if (err) return err; if (ctrl != rv8803->ctrl) { rv8803->ctrl = ctrl; err = rv8803_write_reg(client, RV8803_CTRL, rv8803->ctrl); if (err) return err; } return 0; } static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) { struct i2c_client *client = to_i2c_client(dev); struct rv8803_data *rv8803 = dev_get_drvdata(dev); unsigned int vl = 0; int flags, ret = 0; switch (cmd) { case RTC_VL_READ: flags = rv8803_read_reg(client, RV8803_FLAG); if (flags < 0) return flags; if (flags & RV8803_FLAG_V1F) { dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n"); vl = RTC_VL_ACCURACY_LOW; } if (flags & RV8803_FLAG_V2F) vl |= RTC_VL_DATA_INVALID; return put_user(vl, (unsigned int __user *)arg); case RTC_VL_CLR: mutex_lock(&rv8803->flags_lock); flags = rv8803_read_reg(client, RV8803_FLAG); if (flags < 0) { mutex_unlock(&rv8803->flags_lock); return flags; } flags &= ~RV8803_FLAG_V1F; ret = rv8803_write_reg(client, RV8803_FLAG, flags); mutex_unlock(&rv8803->flags_lock); if (ret) return ret; return 0; default: return -ENOIOCTLCMD; } } static int rv8803_nvram_write(void *priv, unsigned int offset, void *val, size_t bytes) { return rv8803_write_reg(priv, RV8803_RAM, *(u8 *)val); } static int rv8803_nvram_read(void *priv, unsigned int offset, void *val, size_t bytes) { int ret; ret = rv8803_read_reg(priv, RV8803_RAM); if (ret < 0) return ret; *(u8 *)val = ret; return 0; } static const struct rtc_class_ops rv8803_rtc_ops = { .read_time = rv8803_get_time, .set_time = rv8803_set_time, .ioctl = rv8803_ioctl, .read_alarm = rv8803_get_alarm, .set_alarm = rv8803_set_alarm, .alarm_irq_enable = rv8803_alarm_irq_enable, }; static int rx8900_trickle_charger_init(struct rv8803_data *rv8803) { struct i2c_client *client = rv8803->client; struct device_node *node = client->dev.of_node; int err; u8 flags; if (!node) return 0; if (rv8803->type != rx_8900) return 0; err = i2c_smbus_read_byte_data(rv8803->client, RX8900_BACKUP_CTRL); if (err < 0) return err; flags = (u8)err; flags &= ~(RX8900_FLAG_VDETOFF | RX8900_FLAG_SWOFF); flags |= rv8803->backup; return i2c_smbus_write_byte_data(rv8803->client, RX8900_BACKUP_CTRL, flags); } /* configure registers with values different than the Power-On reset defaults */ static int rv8803_regs_configure(struct rv8803_data *rv8803) { int err; err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA); if (err) return err; err = rx8900_trickle_charger_init(rv8803); if (err) { dev_err(&rv8803->client->dev, "failed to init charger\n"); return err; } return 0; } static int rv8803_resume(struct device *dev) { struct rv8803_data *rv8803 = dev_get_drvdata(dev); if (rv8803->client->irq > 0 && device_may_wakeup(dev)) disable_irq_wake(rv8803->client->irq); return 0; } static int rv8803_suspend(struct device *dev) { struct rv8803_data *rv8803 = dev_get_drvdata(dev); if (rv8803->client->irq > 0 && device_may_wakeup(dev)) enable_irq_wake(rv8803->client->irq); return 0; } static DEFINE_SIMPLE_DEV_PM_OPS(rv8803_pm_ops, rv8803_suspend, rv8803_resume); static const struct i2c_device_id rv8803_id[] = { { "rv8803", rv_8803 }, { "rv8804", rx_8804 }, { "rx8803", rx_8803 }, { "rx8900", rx_8900 }, { } }; MODULE_DEVICE_TABLE(i2c, rv8803_id); static int rv8803_probe(struct i2c_client *client) { struct i2c_adapter *adapter = client->adapter; struct rv8803_data *rv8803; int err, flags; struct nvmem_config nvmem_cfg = { .name = "rv8803_nvram", .word_size = 1, .stride = 1, .size = 1, .reg_read = rv8803_nvram_read, .reg_write = rv8803_nvram_write, .priv = client, }; if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK)) { dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_I2C_BLOCK\n"); return -EIO; } rv8803 = devm_kzalloc(&client->dev, sizeof(struct rv8803_data), GFP_KERNEL); if (!rv8803) return -ENOMEM; mutex_init(&rv8803->flags_lock); rv8803->client = client; if (client->dev.of_node) { rv8803->type = (uintptr_t)of_device_get_match_data(&client->dev); } else { const struct i2c_device_id *id = i2c_match_id(rv8803_id, client); rv8803->type = id->driver_data; } i2c_set_clientdata(client, rv8803); flags = rv8803_read_reg(client, RV8803_FLAG); if (flags < 0) return flags; if (flags & RV8803_FLAG_V1F) dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n"); if (flags & RV8803_FLAG_V2F) dev_warn(&client->dev, "Voltage low, data loss detected.\n"); if (flags & RV8803_FLAG_AF) dev_warn(&client->dev, "An alarm maybe have been missed.\n"); rv8803->rtc = devm_rtc_allocate_device(&client->dev); if (IS_ERR(rv8803->rtc)) return PTR_ERR(rv8803->rtc); if (client->irq > 0) { unsigned long irqflags = IRQF_TRIGGER_LOW; if (dev_fwnode(&client->dev)) irqflags = 0; err = devm_request_threaded_irq(&client->dev, client->irq, NULL, rv8803_handle_irq, irqflags | IRQF_ONESHOT, "rv8803", client); if (err) { dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n"); client->irq = 0; } else { device_init_wakeup(&client->dev, true); err = dev_pm_set_wake_irq(&client->dev, client->irq); if (err) dev_err(&client->dev, "failed to set wake IRQ\n"); } } if (!client->irq) clear_bit(RTC_FEATURE_ALARM, rv8803->rtc->features); if (of_property_read_bool(client->dev.of_node, "epson,vdet-disable")) rv8803->backup |= RX8900_FLAG_VDETOFF; if (of_property_read_bool(client->dev.of_node, "trickle-diode-disable")) rv8803->backup |= RX8900_FLAG_SWOFF; err = rv8803_regs_configure(rv8803); if (err) return err; rv8803->rtc->ops = &rv8803_rtc_ops; rv8803->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000; rv8803->rtc->range_max = RTC_TIMESTAMP_END_2099; err = devm_rtc_register_device(rv8803->rtc); if (err) return err; devm_rtc_nvmem_register(rv8803->rtc, &nvmem_cfg); rv8803->rtc->max_user_freq = 1; return 0; } static const __maybe_unused struct of_device_id rv8803_of_match[] = { { .compatible = "microcrystal,rv8803", .data = (void *)rv_8803 }, { .compatible = "epson,rx8803", .data = (void *)rx_8803 }, { .compatible = "epson,rx8804", .data = (void *)rx_8804 }, { .compatible = "epson,rx8900", .data = (void *)rx_8900 }, { } }; MODULE_DEVICE_TABLE(of, rv8803_of_match); static struct i2c_driver rv8803_driver = { .driver = { .name = "rtc-rv8803", .of_match_table = of_match_ptr(rv8803_of_match), .pm = &rv8803_pm_ops, }, .probe = rv8803_probe, .id_table = rv8803_id, }; module_i2c_driver(rv8803_driver); MODULE_AUTHOR("Alexandre Belloni "); MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver"); MODULE_LICENSE("GPL v2");