[linux-block.git] / drivers / rtc / rtc-rv8803.c

// 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_device.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;
	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)
{
	/*
	 * 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 (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;

	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) {
		ret = rv8803_regs_reset(rv8803);
		if (ret) {
			mutex_unlock(&rv8803->flags_lock);
			return ret;
		}
	}

	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;

	alrm->time.tm_sec  = 0;
	alrm->time.tm_min  = bcd2bin(alarmvals[0] & 0x7f);
	alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
	alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);

	alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE);
	alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled;

	return 0;
}

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 = (enum rv8803_type)
			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) {
		err = devm_request_threaded_irq(&client->dev, client->irq,
						NULL, rv8803_handle_irq,
						IRQF_TRIGGER_LOW | 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_new	= 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");
Commit	Line	Data
182ae2bb	1	// SPDX-License-Identifier: GPL-2.0
1e3929ef AB	2	/*
	3	* RTC driver for the Micro Crystal RV8803
	4	*
	5	* Copyright (C) 2015 Micro Crystal SA
7d1e5bfe	6	* Alexandre Belloni <alexandre.belloni@bootlin.com>
1e3929ef	7	*
1e3929ef AB	8	*/
	9
	10	#include <linux/bcd.h>
	11	#include <linux/bitops.h>
c27fee16	12	#include <linux/bitfield.h>
a1e98e09	13	#include <linux/log2.h>
1e3929ef AB	14	#include <linux/i2c.h>
	15	#include <linux/interrupt.h>
	16	#include <linux/kernel.h>
	17	#include <linux/module.h>
740ad8f4	18	#include <linux/of_device.h>
1e3929ef AB	19	#include <linux/rtc.h>
1e3929ef AB	20
d522649e BT	21	#define RV8803_I2C_TRY_COUNT 4
d522649e BT	22
1e3929ef AB	23	#define RV8803_SEC 0x00
	24	#define RV8803_MIN 0x01
	25	#define RV8803_HOUR 0x02
	26	#define RV8803_WEEK 0x03
	27	#define RV8803_DAY 0x04
	28	#define RV8803_MONTH 0x05
	29	#define RV8803_YEAR 0x06
	30	#define RV8803_RAM 0x07
	31	#define RV8803_ALARM_MIN 0x08
	32	#define RV8803_ALARM_HOUR 0x09
	33	#define RV8803_ALARM_WEEK_OR_DAY 0x0A
	34	#define RV8803_EXT 0x0D
	35	#define RV8803_FLAG 0x0E
	36	#define RV8803_CTRL 0x0F
c27fee16	37	#define RV8803_OSC_OFFSET 0x2C
1e3929ef AB	38
	39	#define RV8803_EXT_WADA BIT(6)
	40
	41	#define RV8803_FLAG_V1F BIT(0)
	42	#define RV8803_FLAG_V2F BIT(1)
	43	#define RV8803_FLAG_AF BIT(3)
	44	#define RV8803_FLAG_TF BIT(4)
	45	#define RV8803_FLAG_UF BIT(5)
	46
	47	#define RV8803_CTRL_RESET BIT(0)
	48
	49	#define RV8803_CTRL_EIE BIT(2)
	50	#define RV8803_CTRL_AIE BIT(3)
	51	#define RV8803_CTRL_TIE BIT(4)
	52	#define RV8803_CTRL_UIE BIT(5)
	53
c27fee16 AF	54	#define RX8803_CTRL_CSEL GENMASK(7, 6)
c27fee16 AF	55
1cd71376 OR	56	#define RX8900_BACKUP_CTRL 0x18
	57	#define RX8900_FLAG_SWOFF BIT(2)
	58	#define RX8900_FLAG_VDETOFF BIT(3)
	59
	60	enum rv8803_type {
	61	rv_8803,
c27fee16	62	rx_8803,
5c0189a8	63	rx_8804,
1cd71376 OR	64	rx_8900
	65	};
	66
1e3929ef AB	67	struct rv8803_data {
	68	struct i2c_client *client;
	69	struct rtc_device *rtc;
9d1fa4c3	70	struct mutex flags_lock;
1e3929ef	71	u8 ctrl;
8c798e1e	72	u8 backup;
1cd71376	73	enum rv8803_type type;
1e3929ef AB	74	};
1e3929ef AB	75
d522649e BT	76	static int rv8803_read_reg(const struct i2c_client *client, u8 reg)
	77	{
	78	int try = RV8803_I2C_TRY_COUNT;
	79	s32 ret;
	80
	81	/*
	82	* There is a 61µs window during which the RTC does not acknowledge I2C
	83	* transfers. In that case, ensure that there are multiple attempts.
	84	*/
	85	do
	86	ret = i2c_smbus_read_byte_data(client, reg);
	87	while ((ret == -ENXIO \|\| ret == -EIO) && --try);
	88	if (ret < 0)
	89	dev_err(&client->dev, "Unable to read register 0x%02x\n", reg);
	90
	91	return ret;
	92	}
	93
	94	static int rv8803_read_regs(const struct i2c_client *client,
	95	u8 reg, u8 count, u8 *values)
	96	{
	97	int try = RV8803_I2C_TRY_COUNT;
	98	s32 ret;
	99
	100	do
	101	ret = i2c_smbus_read_i2c_block_data(client, reg, count, values);
	102	while ((ret == -ENXIO \|\| ret == -EIO) && --try);
	103	if (ret != count) {
	104	dev_err(&client->dev,
	105	"Unable to read registers 0x%02x..0x%02x\n",
	106	reg, reg + count - 1);
	107	return ret < 0 ? ret : -EIO;
	108	}
	109
	110	return 0;
	111	}
	112
	113	static int rv8803_write_reg(const struct i2c_client *client, u8 reg, u8 value)
	114	{
	115	int try = RV8803_I2C_TRY_COUNT;
	116	s32 ret;
	117
	118	do
	119	ret = i2c_smbus_write_byte_data(client, reg, value);
	120	while ((ret == -ENXIO \|\| ret == -EIO) && --try);
	121	if (ret)
	122	dev_err(&client->dev, "Unable to write register 0x%02x\n", reg);
	123
	124	return ret;
	125	}
	126
	127	static int rv8803_write_regs(const struct i2c_client *client,
	128	u8 reg, u8 count, const u8 *values)
	129	{
	130	int try = RV8803_I2C_TRY_COUNT;
	131	s32 ret;
	132
	133	do
	134	ret = i2c_smbus_write_i2c_block_data(client, reg, count,
	135	values);
	136	while ((ret == -ENXIO \|\| ret == -EIO) && --try);
	137	if (ret)
	138	dev_err(&client->dev,
	139	"Unable to write registers 0x%02x..0x%02x\n",
140	reg, reg + count - 1);
141
142	return ret;
143	}
144
c27fee16 AF	145	static int rv8803_regs_init(struct rv8803_data *rv8803)
	146	{
	147	int ret;
	148
	149	ret = rv8803_write_reg(rv8803->client, RV8803_OSC_OFFSET, 0x00);
	150	if (ret)
	151	return ret;
	152
	153	ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
	154	FIELD_PREP(RX8803_CTRL_CSEL, 1)); /* 2s */
	155	if (ret)
	156	return ret;
	157
	158	ret = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3,
	159	(u8[]){ 0, 0, 0 });
	160	if (ret)
	161	return ret;
	162
	163	return rv8803_write_reg(rv8803->client, RV8803_RAM, 0x00);
	164	}
	165
f8176e0b AF	166	static int rv8803_regs_configure(struct rv8803_data *rv8803);
	167
	168	static int rv8803_regs_reset(struct rv8803_data *rv8803)
	169	{
c27fee16 AF	170	/*
	171	* The RV-8803 resets all registers to POR defaults after voltage-loss,
	172	* the Epson RTCs don't, so we manually reset the remainder here.
	173	*/
	174	if (rv8803->type == rx_8803 \|\| rv8803->type == rx_8900) {
	175	int ret = rv8803_regs_init(rv8803);
	176	if (ret)
	177	return ret;
	178	}
	179
f8176e0b AF	180	return rv8803_regs_configure(rv8803);
	181	}
	182
1e3929ef AB	183	static irqreturn_t rv8803_handle_irq(int irq, void *dev_id)
	184	{
	185	struct i2c_client *client = dev_id;
	186	struct rv8803_data *rv8803 = i2c_get_clientdata(client);
	187	unsigned long events = 0;
d522649e	188	int flags;
1e3929ef	189
9d1fa4c3	190	mutex_lock(&rv8803->flags_lock);
1e3929ef	191
d522649e	192	flags = rv8803_read_reg(client, RV8803_FLAG);
1e3929ef	193	if (flags <= 0) {
9d1fa4c3	194	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	195	return IRQ_NONE;
	196	}
	197
	198	if (flags & RV8803_FLAG_V1F)
	199	dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
	200
	201	if (flags & RV8803_FLAG_V2F)
	202	dev_warn(&client->dev, "Voltage low, data loss detected.\n");
	203
	204	if (flags & RV8803_FLAG_TF) {
	205	flags &= ~RV8803_FLAG_TF;
	206	rv8803->ctrl &= ~RV8803_CTRL_TIE;
	207	events \|= RTC_PF;
	208	}
	209
	210	if (flags & RV8803_FLAG_AF) {
	211	flags &= ~RV8803_FLAG_AF;
	212	rv8803->ctrl &= ~RV8803_CTRL_AIE;
	213	events \|= RTC_AF;
	214	}
	215
	216	if (flags & RV8803_FLAG_UF) {
	217	flags &= ~RV8803_FLAG_UF;
	218	rv8803->ctrl &= ~RV8803_CTRL_UIE;
	219	events \|= RTC_UF;
	220	}
	221
	222	if (events) {
	223	rtc_update_irq(rv8803->rtc, 1, events);
d522649e BT	224	rv8803_write_reg(client, RV8803_FLAG, flags);
d522649e BT	225	rv8803_write_reg(rv8803->client, RV8803_CTRL, rv8803->ctrl);
1e3929ef AB	226	}
1e3929ef AB	227
9d1fa4c3	228	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	229
	230	return IRQ_HANDLED;
	231	}
	232
	233	static int rv8803_get_time(struct device dev, struct rtc_time tm)
	234	{
	235	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
	236	u8 date1[7];
	237	u8 date2[7];
	238	u8 *date = date1;
	239	int ret, flags;
	240
d522649e	241	flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
1e3929ef AB	242	if (flags < 0)
	243	return flags;
	244
	245	if (flags & RV8803_FLAG_V2F) {
	246	dev_warn(dev, "Voltage low, data is invalid.\n");
	247	return -EINVAL;
	248	}
	249
d522649e BT	250	ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date);
	251	if (ret)
	252	return ret;
1e3929ef AB	253
1e3929ef AB	254	if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) {
d522649e BT	255	ret = rv8803_read_regs(rv8803->client, RV8803_SEC, 7, date2);
	256	if (ret)
	257	return ret;
1e3929ef AB	258
	259	if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59))
	260	date = date2;
	261	}
	262
	263	tm->tm_sec = bcd2bin(date[RV8803_SEC] & 0x7f);
	264	tm->tm_min = bcd2bin(date[RV8803_MIN] & 0x7f);
	265	tm->tm_hour = bcd2bin(date[RV8803_HOUR] & 0x3f);
a1e98e09	266	tm->tm_wday = ilog2(date[RV8803_WEEK] & 0x7f);
1e3929ef AB	267	tm->tm_mday = bcd2bin(date[RV8803_DAY] & 0x3f);
	268	tm->tm_mon = bcd2bin(date[RV8803_MONTH] & 0x1f) - 1;
	269	tm->tm_year = bcd2bin(date[RV8803_YEAR]) + 100;
	270
96acb25c	271	return 0;
1e3929ef AB	272	}
	273
	274	static int rv8803_set_time(struct device dev, struct rtc_time tm)
	275	{
	276	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
	277	u8 date[7];
d3700b6b	278	int ctrl, flags, ret;
1e3929ef	279
d3700b6b BT	280	ctrl = rv8803_read_reg(rv8803->client, RV8803_CTRL);
	281	if (ctrl < 0)
	282	return ctrl;
	283
	284	/* Stop the clock */
	285	ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
	286	ctrl \| RV8803_CTRL_RESET);
	287	if (ret)
	288	return ret;
	289
1e3929ef AB	290	date[RV8803_SEC] = bin2bcd(tm->tm_sec);
	291	date[RV8803_MIN] = bin2bcd(tm->tm_min);
	292	date[RV8803_HOUR] = bin2bcd(tm->tm_hour);
	293	date[RV8803_WEEK] = 1 << (tm->tm_wday);
	294	date[RV8803_DAY] = bin2bcd(tm->tm_mday);
	295	date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1);
	296	date[RV8803_YEAR] = bin2bcd(tm->tm_year - 100);
	297
d522649e BT	298	ret = rv8803_write_regs(rv8803->client, RV8803_SEC, 7, date);
d522649e BT	299	if (ret)
1e3929ef AB	300	return ret;
1e3929ef AB	301
d3700b6b BT	302	/* Restart the clock */
	303	ret = rv8803_write_reg(rv8803->client, RV8803_CTRL,
	304	ctrl & ~RV8803_CTRL_RESET);
	305	if (ret)
	306	return ret;
	307
9d1fa4c3	308	mutex_lock(&rv8803->flags_lock);
1e3929ef	309
d522649e	310	flags = rv8803_read_reg(rv8803->client, RV8803_FLAG);
1e3929ef	311	if (flags < 0) {
9d1fa4c3	312	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	313	return flags;
	314	}
	315
f8176e0b AF	316	if (flags & RV8803_FLAG_V2F) {
f8176e0b AF	317	ret = rv8803_regs_reset(rv8803);
bb42b7e9 YY	318	if (ret) {
bb42b7e9 YY	319	mutex_unlock(&rv8803->flags_lock);
f8176e0b	320	return ret;
bb42b7e9	321	}
f8176e0b AF	322	}
f8176e0b AF	323
d522649e	324	ret = rv8803_write_reg(rv8803->client, RV8803_FLAG,
6f367788	325	flags & ~(RV8803_FLAG_V1F \| RV8803_FLAG_V2F));
1e3929ef	326
9d1fa4c3	327	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	328
	329	return ret;
	330	}
	331
	332	static int rv8803_get_alarm(struct device dev, struct rtc_wkalrm alrm)
	333	{
	334	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
	335	struct i2c_client *client = rv8803->client;
	336	u8 alarmvals[3];
	337	int flags, ret;
	338
d522649e BT	339	ret = rv8803_read_regs(client, RV8803_ALARM_MIN, 3, alarmvals);
	340	if (ret)
	341	return ret;
1e3929ef	342
d522649e	343	flags = rv8803_read_reg(client, RV8803_FLAG);
1e3929ef AB	344	if (flags < 0)
	345	return flags;
	346
	347	alrm->time.tm_sec = 0;
	348	alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
	349	alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
1e3929ef	350	alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
1e3929ef AB	351
	352	alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE);
	353	alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled;
	354
	355	return 0;
	356	}
	357
	358	static int rv8803_set_alarm(struct device dev, struct rtc_wkalrm alrm)
	359	{
	360	struct i2c_client *client = to_i2c_client(dev);
	361	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
	362	u8 alarmvals[3];
	363	u8 ctrl[2];
	364	int ret, err;
1e3929ef AB	365
	366	/* The alarm has no seconds, round up to nearest minute */
	367	if (alrm->time.tm_sec) {
	368	time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
	369
	370	alarm_time += 60 - alrm->time.tm_sec;
	371	rtc_time64_to_tm(alarm_time, &alrm->time);
	372	}
	373
9d1fa4c3	374	mutex_lock(&rv8803->flags_lock);
1e3929ef	375
d522649e BT	376	ret = rv8803_read_regs(client, RV8803_FLAG, 2, ctrl);
d522649e BT	377	if (ret) {
9d1fa4c3	378	mutex_unlock(&rv8803->flags_lock);
d522649e	379	return ret;
1e3929ef AB	380	}
	381
	382	alarmvals[0] = bin2bcd(alrm->time.tm_min);
	383	alarmvals[1] = bin2bcd(alrm->time.tm_hour);
	384	alarmvals[2] = bin2bcd(alrm->time.tm_mday);
	385
	386	if (rv8803->ctrl & (RV8803_CTRL_AIE \| RV8803_CTRL_UIE)) {
	387	rv8803->ctrl &= ~(RV8803_CTRL_AIE \| RV8803_CTRL_UIE);
d522649e BT	388	err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
d522649e BT	389	rv8803->ctrl);
1e3929ef	390	if (err) {
9d1fa4c3	391	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	392	return err;
	393	}
	394	}
	395
03a86cda DM	396	ctrl[0] &= ~RV8803_FLAG_AF;
03a86cda DM	397	err = rv8803_write_reg(rv8803->client, RV8803_FLAG, ctrl[0]);
9d1fa4c3	398	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	399	if (err)
	400	return err;
	401
d522649e	402	err = rv8803_write_regs(rv8803->client, RV8803_ALARM_MIN, 3, alarmvals);
1e3929ef AB	403	if (err)
	404	return err;
	405
	406	if (alrm->enabled) {
	407	if (rv8803->rtc->uie_rtctimer.enabled)
	408	rv8803->ctrl \|= RV8803_CTRL_UIE;
	409	if (rv8803->rtc->aie_timer.enabled)
	410	rv8803->ctrl \|= RV8803_CTRL_AIE;
	411
d522649e BT	412	err = rv8803_write_reg(rv8803->client, RV8803_CTRL,
d522649e BT	413	rv8803->ctrl);
1e3929ef AB	414	if (err)
	415	return err;
	416	}
	417
	418	return 0;
	419	}
	420
	421	static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled)
	422	{
	423	struct i2c_client *client = to_i2c_client(dev);
	424	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
	425	int ctrl, flags, err;
1e3929ef AB	426
	427	ctrl = rv8803->ctrl;
	428
	429	if (enabled) {
	430	if (rv8803->rtc->uie_rtctimer.enabled)
	431	ctrl \|= RV8803_CTRL_UIE;
	432	if (rv8803->rtc->aie_timer.enabled)
	433	ctrl \|= RV8803_CTRL_AIE;
	434	} else {
	435	if (!rv8803->rtc->uie_rtctimer.enabled)
	436	ctrl &= ~RV8803_CTRL_UIE;
	437	if (!rv8803->rtc->aie_timer.enabled)
	438	ctrl &= ~RV8803_CTRL_AIE;
	439	}
	440
9d1fa4c3	441	mutex_lock(&rv8803->flags_lock);
d522649e	442	flags = rv8803_read_reg(client, RV8803_FLAG);
1e3929ef	443	if (flags < 0) {
9d1fa4c3	444	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	445	return flags;
	446	}
	447	flags &= ~(RV8803_FLAG_AF \| RV8803_FLAG_UF);
d522649e	448	err = rv8803_write_reg(client, RV8803_FLAG, flags);
9d1fa4c3	449	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	450	if (err)
	451	return err;
	452
	453	if (ctrl != rv8803->ctrl) {
	454	rv8803->ctrl = ctrl;
d522649e	455	err = rv8803_write_reg(client, RV8803_CTRL, rv8803->ctrl);
1e3929ef AB	456	if (err)
	457	return err;
	458	}
	459
	460	return 0;
	461	}
	462
	463	static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
	464	{
	465	struct i2c_client *client = to_i2c_client(dev);
	466	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
bcd17c50	467	unsigned int vl = 0;
1e3929ef	468	int flags, ret = 0;
1e3929ef AB	469
	470	switch (cmd) {
	471	case RTC_VL_READ:
d522649e	472	flags = rv8803_read_reg(client, RV8803_FLAG);
1e3929ef AB	473	if (flags < 0)
	474	return flags;
	475
bcd17c50	476	if (flags & RV8803_FLAG_V1F) {
1e3929ef	477	dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
bcd17c50 AB	478	vl = RTC_VL_ACCURACY_LOW;
bcd17c50 AB	479	}
1e3929ef AB	480
1e3929ef AB	481	if (flags & RV8803_FLAG_V2F)
bcd17c50	482	vl \|= RTC_VL_DATA_INVALID;
1e3929ef	483
bcd17c50	484	return put_user(vl, (unsigned int __user *)arg);
1e3929ef AB	485
1e3929ef AB	486	case RTC_VL_CLR:
9d1fa4c3	487	mutex_lock(&rv8803->flags_lock);
d522649e	488	flags = rv8803_read_reg(client, RV8803_FLAG);
1e3929ef	489	if (flags < 0) {
9d1fa4c3	490	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	491	return flags;
	492	}
	493
7e890a0f	494	flags &= ~RV8803_FLAG_V1F;
d522649e	495	ret = rv8803_write_reg(client, RV8803_FLAG, flags);
9d1fa4c3	496	mutex_unlock(&rv8803->flags_lock);
d522649e	497	if (ret)
1e3929ef AB	498	return ret;
	499
	500	return 0;
	501
	502	default:
	503	return -ENOIOCTLCMD;
	504	}
	505	}
	506
16d70a78 AB	507	static int rv8803_nvram_write(void priv, unsigned int offset, void val,
16d70a78 AB	508	size_t bytes)
1e3929ef	509	{
179b4bcc	510	return rv8803_write_reg(priv, RV8803_RAM, (u8 )val);
1e3929ef AB	511	}
1e3929ef AB	512
16d70a78 AB	513	static int rv8803_nvram_read(void *priv, unsigned int offset,
16d70a78 AB	514	void *val, size_t bytes)
1e3929ef	515	{
1e3929ef AB	516	int ret;
1e3929ef AB	517
16d70a78	518	ret = rv8803_read_reg(priv, RV8803_RAM);
1e3929ef AB	519	if (ret < 0)
	520	return ret;
	521
16d70a78	522	(u8 )val = ret;
1e3929ef	523
16d70a78	524	return 0;
1e3929ef AB	525	}
1e3929ef AB	526
45909e5c	527	static const struct rtc_class_ops rv8803_rtc_ops = {
1e3929ef AB	528	.read_time = rv8803_get_time,
	529	.set_time = rv8803_set_time,
	530	.ioctl = rv8803_ioctl,
45909e5c AB	531	.read_alarm = rv8803_get_alarm,
	532	.set_alarm = rv8803_set_alarm,
	533	.alarm_irq_enable = rv8803_alarm_irq_enable,
1e3929ef AB	534	};
1e3929ef AB	535
1cd71376 OR	536	static int rx8900_trickle_charger_init(struct rv8803_data *rv8803)
	537	{
	538	struct i2c_client *client = rv8803->client;
	539	struct device_node *node = client->dev.of_node;
	540	int err;
	541	u8 flags;
	542
	543	if (!node)
	544	return 0;
	545
	546	if (rv8803->type != rx_8900)
	547	return 0;
	548
	549	err = i2c_smbus_read_byte_data(rv8803->client, RX8900_BACKUP_CTRL);
	550	if (err < 0)
	551	return err;
	552
8c798e1e AF	553	flags = (u8)err;
	554	flags &= ~(RX8900_FLAG_VDETOFF \| RX8900_FLAG_SWOFF);
	555	flags \|= rv8803->backup;
1cd71376 OR	556
	557	return i2c_smbus_write_byte_data(rv8803->client, RX8900_BACKUP_CTRL,
	558	flags);
	559	}
	560
8c798e1e AF	561	/* configure registers with values different than the Power-On reset defaults */
	562	static int rv8803_regs_configure(struct rv8803_data *rv8803)
	563	{
	564	int err;
	565
	566	err = rv8803_write_reg(rv8803->client, RV8803_EXT, RV8803_EXT_WADA);
	567	if (err)
	568	return err;
	569
	570	err = rx8900_trickle_charger_init(rv8803);
	571	if (err) {
	572	dev_err(&rv8803->client->dev, "failed to init charger\n");
	573	return err;
	574	}
	575
	576	return 0;
	577	}
	578
84c2fb38 UKK	579	static const struct i2c_device_id rv8803_id[] = {
	580	{ "rv8803", rv_8803 },
	581	{ "rv8804", rx_8804 },
	582	{ "rx8803", rx_8803 },
	583	{ "rx8900", rx_8900 },
	584	{ }
	585	};
	586	MODULE_DEVICE_TABLE(i2c, rv8803_id);
	587
	588	static int rv8803_probe(struct i2c_client *client)
1e3929ef	589	{
5cb17269	590	struct i2c_adapter *adapter = client->adapter;
1e3929ef	591	struct rv8803_data *rv8803;
d522649e	592	int err, flags;
c07fd9de AB	593	struct nvmem_config nvmem_cfg = {
	594	.name = "rv8803_nvram",
	595	.word_size = 1,
	596	.stride = 1,
	597	.size = 1,
	598	.reg_read = rv8803_nvram_read,
	599	.reg_write = rv8803_nvram_write,
	600	.priv = client,
	601	};
1e3929ef AB	602
	603	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA \|
	604	I2C_FUNC_SMBUS_I2C_BLOCK)) {
	605	dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA \| I2C_FUNC_SMBUS_I2C_BLOCK\n");
	606	return -EIO;
	607	}
	608
	609	rv8803 = devm_kzalloc(&client->dev, sizeof(struct rv8803_data),
	610	GFP_KERNEL);
	611	if (!rv8803)
	612	return -ENOMEM;
	613
9d1fa4c3	614	mutex_init(&rv8803->flags_lock);
1e3929ef	615	rv8803->client = client;
84c2fb38	616	if (client->dev.of_node) {
740ad8f4 JMC	617	rv8803->type = (enum rv8803_type)
740ad8f4 JMC	618	of_device_get_match_data(&client->dev);
84c2fb38 UKK	619	} else {
	620	const struct i2c_device_id *id = i2c_match_id(rv8803_id, client);
	621
740ad8f4	622	rv8803->type = id->driver_data;
84c2fb38	623	}
1e3929ef AB	624	i2c_set_clientdata(client, rv8803);
1e3929ef AB	625
d522649e	626	flags = rv8803_read_reg(client, RV8803_FLAG);
1e3929ef AB	627	if (flags < 0)
	628	return flags;
	629
	630	if (flags & RV8803_FLAG_V1F)
	631	dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
	632
	633	if (flags & RV8803_FLAG_V2F)
	634	dev_warn(&client->dev, "Voltage low, data loss detected.\n");
	635
	636	if (flags & RV8803_FLAG_AF)
	637	dev_warn(&client->dev, "An alarm maybe have been missed.\n");
	638
7133eca1	639	rv8803->rtc = devm_rtc_allocate_device(&client->dev);
44c638ce	640	if (IS_ERR(rv8803->rtc))
7133eca1	641	return PTR_ERR(rv8803->rtc);
7133eca1	642
1e3929ef AB	643	if (client->irq > 0) {
	644	err = devm_request_threaded_irq(&client->dev, client->irq,
	645	NULL, rv8803_handle_irq,
	646	IRQF_TRIGGER_LOW \| IRQF_ONESHOT,
	647	"rv8803", client);
	648	if (err) {
	649	dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
	650	client->irq = 0;
1e3929ef AB	651	}
1e3929ef AB	652	}
45909e5c AB	653	if (!client->irq)
45909e5c AB	654	clear_bit(RTC_FEATURE_ALARM, rv8803->rtc->features);
1e3929ef	655
8c798e1e AF	656	if (of_property_read_bool(client->dev.of_node, "epson,vdet-disable"))
8c798e1e AF	657	rv8803->backup \|= RX8900_FLAG_VDETOFF;
1e3929ef	658
8c798e1e AF	659	if (of_property_read_bool(client->dev.of_node, "trickle-diode-disable"))
	660	rv8803->backup \|= RX8900_FLAG_SWOFF;
	661
	662	err = rv8803_regs_configure(rv8803);
	663	if (err)
1cd71376	664	return err;
1cd71376	665
ce1ae8eb	666	rv8803->rtc->ops = &rv8803_rtc_ops;
2e17f8b9 AB	667	rv8803->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
2e17f8b9 AB	668	rv8803->rtc->range_max = RTC_TIMESTAMP_END_2099;
fdcfd854	669	err = devm_rtc_register_device(rv8803->rtc);
ce1ae8eb AB	670	if (err)
	671	return err;
	672
3a905c2d	673	devm_rtc_nvmem_register(rv8803->rtc, &nvmem_cfg);
ce1ae8eb	674
1e3929ef AB	675	rv8803->rtc->max_user_freq = 1;
	676
	677	return 0;
	678	}
	679
da826321	680	static const __maybe_unused struct of_device_id rv8803_of_match[] = {
740ad8f4 JMC	681	{
740ad8f4 JMC	682	.compatible = "microcrystal,rv8803",
c856618d	683	.data = (void *)rv_8803
740ad8f4	684	},
ac771ed7 AB	685	{
ac771ed7 AB	686	.compatible = "epson,rx8803",
c27fee16	687	.data = (void *)rx_8803
ac771ed7	688	},
5c0189a8 FE	689	{
	690	.compatible = "epson,rx8804",
	691	.data = (void *)rx_8804
	692	},
740ad8f4 JMC	693	{
	694	.compatible = "epson,rx8900",
	695	.data = (void *)rx_8900
	696	},
	697	{ }
	698	};
	699	MODULE_DEVICE_TABLE(of, rv8803_of_match);
	700
1e3929ef AB	701	static struct i2c_driver rv8803_driver = {
	702	.driver = {
	703	.name = "rtc-rv8803",
740ad8f4	704	.of_match_table = of_match_ptr(rv8803_of_match),
1e3929ef	705	},
84c2fb38	706	.probe_new = rv8803_probe,
1e3929ef AB	707	.id_table = rv8803_id,
	708	};
	709	module_i2c_driver(rv8803_driver);
	710
7d1e5bfe	711	MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@bootlin.com>");
1e3929ef AB	712	MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver");
1e3929ef AB	713	MODULE_LICENSE("GPL v2");