Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 748 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-rv8803.c b/drivers/rtc/rtc-rv8803.c
new file mode 100644
index 0000000000..1a3ec1bb5b
--- /dev/null
+++ b/drivers/rtc/rtc-rv8803.c
@@ -0,0 +1,748 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * RTC driver for the Micro Crystal RV8803
+ *
+ * Copyright (C) 2015 Micro Crystal SA
+ * Alexandre Belloni <alexandre.belloni@bootlin.com>
+ *
+ */
+
+#include <linux/bcd.h>
+#include <linux/bitops.h>
+#include <linux/bitfield.h>
+#include <linux/log2.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/rtc.h>
+
+#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 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;
+		}
+	}
+	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),
+	},
+	.probe		= rv8803_probe,
+	.id_table	= rv8803_id,
+};
+module_i2c_driver(rv8803_driver);
+
+MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
+MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver");
+MODULE_LICENSE("GPL v2");