[linux-2.6-block.git] / drivers / rtc / rtc-rv8803.c

/*
 * RTC driver for the Micro Crystal RV8803
 *
 * Copyright (C) 2015 Micro Crystal SA
 *
 * Alexandre Belloni <alexandre.belloni@free-electrons.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/bcd.h>
#include <linux/bitops.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtc.h>

#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_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)

struct rv8803_data {
	struct i2c_client *client;
	struct rtc_device *rtc;
	struct mutex flags_lock;
	u8 ctrl;
};

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, try = 0;

	mutex_lock(&rv8803->flags_lock);

	do {
		flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
		try++;
	} while ((flags == -ENXIO) && (try < 3));
	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);
		i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
		i2c_smbus_write_byte_data(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 = i2c_smbus_read_byte_data(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 = i2c_smbus_read_i2c_block_data(rv8803->client, RV8803_SEC,
					    7, date);
	if (ret != 7)
		return ret < 0 ? ret : -EIO;

	if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) {
		ret = i2c_smbus_read_i2c_block_data(rv8803->client, RV8803_SEC,
						    7, date2);
		if (ret != 7)
			return ret < 0 ? ret : -EIO;

		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 = ffs(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 rtc_valid_tm(tm);
}

static int rv8803_set_time(struct device *dev, struct rtc_time *tm)
{
	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
	u8 date[7];
	int flags, ret;

	if ((tm->tm_year < 100) || (tm->tm_year > 199))
		return -EINVAL;

	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 = i2c_smbus_write_i2c_block_data(rv8803->client, RV8803_SEC,
					     7, date);
	if (ret < 0)
		return ret;

	mutex_lock(&rv8803->flags_lock);

	flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG);
	if (flags < 0) {
		mutex_unlock(&rv8803->flags_lock);
		return flags;
	}

	ret = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG,
					flags & ~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 = i2c_smbus_read_i2c_block_data(client, RV8803_ALARM_MIN,
					    3, alarmvals);
	if (ret != 3)
		return ret < 0 ? ret : -EIO;

	flags = i2c_smbus_read_byte_data(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_wday = -1;
	alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
	alrm->time.tm_mon  = -1;
	alrm->time.tm_year = -1;

	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 = i2c_smbus_read_i2c_block_data(client, RV8803_FLAG, 2, ctrl);
	if (ret != 2) {
		mutex_unlock(&rv8803->flags_lock);
		return ret < 0 ? ret : -EIO;
	}

	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 = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL,
						rv8803->ctrl);
		if (err) {
			mutex_unlock(&rv8803->flags_lock);
			return err;
		}
	}

	ctrl[1] &= ~RV8803_FLAG_AF;
	err = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG, ctrl[1]);
	mutex_unlock(&rv8803->flags_lock);
	if (err)
		return err;

	err = i2c_smbus_write_i2c_block_data(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 = i2c_smbus_write_byte_data(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 = i2c_smbus_read_byte_data(client, RV8803_FLAG);
	if (flags < 0) {
		mutex_unlock(&rv8803->flags_lock);
		return flags;
	}
	flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF);
	err = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
	mutex_unlock(&rv8803->flags_lock);
	if (err)
		return err;

	if (ctrl != rv8803->ctrl) {
		rv8803->ctrl = ctrl;
		err = i2c_smbus_write_byte_data(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);
	int flags, ret = 0;

	switch (cmd) {
	case RTC_VL_READ:
		flags = i2c_smbus_read_byte_data(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");

		flags &= RV8803_FLAG_V1F | RV8803_FLAG_V2F;

		if (copy_to_user((void __user *)arg, &flags, sizeof(int)))
			return -EFAULT;

		return 0;

	case RTC_VL_CLR:
		mutex_lock(&rv8803->flags_lock);
		flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
		if (flags < 0) {
			mutex_unlock(&rv8803->flags_lock);
			return flags;
		}

		flags &= ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F);
		ret = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
		mutex_unlock(&rv8803->flags_lock);
		if (ret < 0)
			return ret;

		return 0;

	default:
		return -ENOIOCTLCMD;
	}
}

static ssize_t rv8803_nvram_write(struct file *filp, struct kobject *kobj,
				  struct bin_attribute *attr,
				  char *buf, loff_t off, size_t count)
{
	struct device *dev = kobj_to_dev(kobj);
	struct i2c_client *client = to_i2c_client(dev);
	int ret;

	ret = i2c_smbus_write_byte_data(client, RV8803_RAM, buf[0]);
	if (ret < 0)
		return ret;

	return 1;
}

static ssize_t rv8803_nvram_read(struct file *filp, struct kobject *kobj,
				 struct bin_attribute *attr,
				 char *buf, loff_t off, size_t count)
{
	struct device *dev = kobj_to_dev(kobj);
	struct i2c_client *client = to_i2c_client(dev);
	int ret;

	ret = i2c_smbus_read_byte_data(client, RV8803_RAM);
	if (ret < 0)
		return ret;

	buf[0] = ret;

	return 1;
}

static struct bin_attribute rv8803_nvram_attr = {
	.attr = {
		.name = "nvram",
		.mode = S_IRUGO | S_IWUSR,
	},
	.size = 1,
	.read = rv8803_nvram_read,
	.write = rv8803_nvram_write,
};

static struct rtc_class_ops rv8803_rtc_ops = {
	.read_time = rv8803_get_time,
	.set_time = rv8803_set_time,
	.ioctl = rv8803_ioctl,
};

static int rv8803_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
	struct rv8803_data *rv8803;
	int err, flags, try = 0;

	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;
	i2c_set_clientdata(client, rv8803);

	/*
	 * There is a 60µs window where the RTC may not reply on the i2c bus in
	 * that case, the transfer is not ACKed. In that case, ensure there are
	 * multiple attempts.
	 */
	do {
		flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
		try++;
	} while ((flags == -ENXIO) && (try < 3));

	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");

	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;
		} else {
			rv8803_rtc_ops.read_alarm = rv8803_get_alarm;
			rv8803_rtc_ops.set_alarm = rv8803_set_alarm;
			rv8803_rtc_ops.alarm_irq_enable = rv8803_alarm_irq_enable;
		}
	}

	rv8803->rtc = devm_rtc_device_register(&client->dev, client->name,
					       &rv8803_rtc_ops, THIS_MODULE);
	if (IS_ERR(rv8803->rtc)) {
		dev_err(&client->dev, "unable to register the class device\n");
		return PTR_ERR(rv8803->rtc);
	}

	try = 0;
	do {
		err = i2c_smbus_write_byte_data(rv8803->client, RV8803_EXT,
						RV8803_EXT_WADA);
		try++;
	} while ((err == -ENXIO) && (try < 3));
	if (err)
		return err;

	err = device_create_bin_file(&client->dev, &rv8803_nvram_attr);
	if (err)
		return err;

	rv8803->rtc->max_user_freq = 1;

	return 0;
}

static int rv8803_remove(struct i2c_client *client)
{
	device_remove_bin_file(&client->dev, &rv8803_nvram_attr);

	return 0;
}

static const struct i2c_device_id rv8803_id[] = {
	{ "rv8803", 0 },
	{ "rx8900", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, rv8803_id);

static struct i2c_driver rv8803_driver = {
	.driver = {
		.name = "rtc-rv8803",
	},
	.probe		= rv8803_probe,
	.remove		= rv8803_remove,
	.id_table	= rv8803_id,
};
module_i2c_driver(rv8803_driver);

MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
1e3929ef AB	1	/*
	2	* RTC driver for the Micro Crystal RV8803
	3	*
	4	* Copyright (C) 2015 Micro Crystal SA
	5	*
	6	* Alexandre Belloni <alexandre.belloni@free-electrons.com>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*
	12	*/
	13
	14	#include <linux/bcd.h>
	15	#include <linux/bitops.h>
	16	#include <linux/i2c.h>
	17	#include <linux/interrupt.h>
	18	#include <linux/kernel.h>
	19	#include <linux/module.h>
	20	#include <linux/rtc.h>
	21
	22	#define RV8803_SEC 0x00
	23	#define RV8803_MIN 0x01
	24	#define RV8803_HOUR 0x02
	25	#define RV8803_WEEK 0x03
	26	#define RV8803_DAY 0x04
	27	#define RV8803_MONTH 0x05
	28	#define RV8803_YEAR 0x06
	29	#define RV8803_RAM 0x07
	30	#define RV8803_ALARM_MIN 0x08
	31	#define RV8803_ALARM_HOUR 0x09
	32	#define RV8803_ALARM_WEEK_OR_DAY 0x0A
	33	#define RV8803_EXT 0x0D
	34	#define RV8803_FLAG 0x0E
	35	#define RV8803_CTRL 0x0F
	36
	37	#define RV8803_EXT_WADA BIT(6)
	38
	39	#define RV8803_FLAG_V1F BIT(0)
	40	#define RV8803_FLAG_V2F BIT(1)
	41	#define RV8803_FLAG_AF BIT(3)
	42	#define RV8803_FLAG_TF BIT(4)
	43	#define RV8803_FLAG_UF BIT(5)
	44
	45	#define RV8803_CTRL_RESET BIT(0)
	46
	47	#define RV8803_CTRL_EIE BIT(2)
	48	#define RV8803_CTRL_AIE BIT(3)
	49	#define RV8803_CTRL_TIE BIT(4)
	50	#define RV8803_CTRL_UIE BIT(5)
	51
	52	struct rv8803_data {
	53	struct i2c_client *client;
	54	struct rtc_device *rtc;
9d1fa4c3	55	struct mutex flags_lock;
1e3929ef AB	56	u8 ctrl;
	57	};
	58
	59	static irqreturn_t rv8803_handle_irq(int irq, void *dev_id)
	60	{
	61	struct i2c_client *client = dev_id;
	62	struct rv8803_data *rv8803 = i2c_get_clientdata(client);
	63	unsigned long events = 0;
85062c9b	64	int flags, try = 0;
1e3929ef	65
9d1fa4c3	66	mutex_lock(&rv8803->flags_lock);
1e3929ef	67
85062c9b AB	68	do {
	69	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
	70	try++;
	71	} while ((flags == -ENXIO) && (try < 3));
1e3929ef	72	if (flags <= 0) {
9d1fa4c3	73	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	74	return IRQ_NONE;
	75	}
	76
	77	if (flags & RV8803_FLAG_V1F)
	78	dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
	79
	80	if (flags & RV8803_FLAG_V2F)
	81	dev_warn(&client->dev, "Voltage low, data loss detected.\n");
	82
	83	if (flags & RV8803_FLAG_TF) {
	84	flags &= ~RV8803_FLAG_TF;
	85	rv8803->ctrl &= ~RV8803_CTRL_TIE;
	86	events \|= RTC_PF;
	87	}
	88
	89	if (flags & RV8803_FLAG_AF) {
	90	flags &= ~RV8803_FLAG_AF;
	91	rv8803->ctrl &= ~RV8803_CTRL_AIE;
	92	events \|= RTC_AF;
	93	}
	94
	95	if (flags & RV8803_FLAG_UF) {
	96	flags &= ~RV8803_FLAG_UF;
	97	rv8803->ctrl &= ~RV8803_CTRL_UIE;
	98	events \|= RTC_UF;
	99	}
	100
	101	if (events) {
	102	rtc_update_irq(rv8803->rtc, 1, events);
	103	i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
	104	i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL,
	105	rv8803->ctrl);
	106	}
	107
9d1fa4c3	108	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	109
	110	return IRQ_HANDLED;
	111	}
	112
	113	static int rv8803_get_time(struct device dev, struct rtc_time tm)
	114	{
	115	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
	116	u8 date1[7];
	117	u8 date2[7];
	118	u8 *date = date1;
	119	int ret, flags;
	120
	121	flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG);
	122	if (flags < 0)
	123	return flags;
	124
	125	if (flags & RV8803_FLAG_V2F) {
	126	dev_warn(dev, "Voltage low, data is invalid.\n");
	127	return -EINVAL;
	128	}
	129
	130	ret = i2c_smbus_read_i2c_block_data(rv8803->client, RV8803_SEC,
	131	7, date);
	132	if (ret != 7)
	133	return ret < 0 ? ret : -EIO;
	134
	135	if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) {
	136	ret = i2c_smbus_read_i2c_block_data(rv8803->client, RV8803_SEC,
	137	7, date2);
	138	if (ret != 7)
	139	return ret < 0 ? ret : -EIO;
	140
	141	if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59))
	142	date = date2;
	143	}
	144
	145	tm->tm_sec = bcd2bin(date[RV8803_SEC] & 0x7f);
	146	tm->tm_min = bcd2bin(date[RV8803_MIN] & 0x7f);
	147	tm->tm_hour = bcd2bin(date[RV8803_HOUR] & 0x3f);
	148	tm->tm_wday = ffs(date[RV8803_WEEK] & 0x7f);
	149	tm->tm_mday = bcd2bin(date[RV8803_DAY] & 0x3f);
	150	tm->tm_mon = bcd2bin(date[RV8803_MONTH] & 0x1f) - 1;
	151	tm->tm_year = bcd2bin(date[RV8803_YEAR]) + 100;
	152
	153	return rtc_valid_tm(tm);
	154	}
	155
	156	static int rv8803_set_time(struct device dev, struct rtc_time tm)
	157	{
	158	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
	159	u8 date[7];
	160	int flags, ret;
1e3929ef AB	161
	162	if ((tm->tm_year < 100) \|\| (tm->tm_year > 199))
	163	return -EINVAL;
	164
	165	date[RV8803_SEC] = bin2bcd(tm->tm_sec);
	166	date[RV8803_MIN] = bin2bcd(tm->tm_min);
	167	date[RV8803_HOUR] = bin2bcd(tm->tm_hour);
	168	date[RV8803_WEEK] = 1 << (tm->tm_wday);
	169	date[RV8803_DAY] = bin2bcd(tm->tm_mday);
	170	date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1);
	171	date[RV8803_YEAR] = bin2bcd(tm->tm_year - 100);
	172
	173	ret = i2c_smbus_write_i2c_block_data(rv8803->client, RV8803_SEC,
	174	7, date);
	175	if (ret < 0)
	176	return ret;
	177
9d1fa4c3	178	mutex_lock(&rv8803->flags_lock);
1e3929ef AB	179
	180	flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG);
	181	if (flags < 0) {
9d1fa4c3	182	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	183	return flags;
	184	}
	185
	186	ret = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG,
	187	flags & ~RV8803_FLAG_V2F);
	188
9d1fa4c3	189	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	190
	191	return ret;
	192	}
	193
	194	static int rv8803_get_alarm(struct device dev, struct rtc_wkalrm alrm)
	195	{
	196	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
	197	struct i2c_client *client = rv8803->client;
	198	u8 alarmvals[3];
	199	int flags, ret;
	200
	201	ret = i2c_smbus_read_i2c_block_data(client, RV8803_ALARM_MIN,
	202	3, alarmvals);
	203	if (ret != 3)
	204	return ret < 0 ? ret : -EIO;
	205
	206	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
	207	if (flags < 0)
	208	return flags;
	209
	210	alrm->time.tm_sec = 0;
	211	alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
	212	alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
	213	alrm->time.tm_wday = -1;
	214	alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
	215	alrm->time.tm_mon = -1;
	216	alrm->time.tm_year = -1;
	217
	218	alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE);
	219	alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled;
	220
	221	return 0;
	222	}
	223
	224	static int rv8803_set_alarm(struct device dev, struct rtc_wkalrm alrm)
	225	{
	226	struct i2c_client *client = to_i2c_client(dev);
	227	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
	228	u8 alarmvals[3];
	229	u8 ctrl[2];
	230	int ret, err;
1e3929ef AB	231
	232	/* The alarm has no seconds, round up to nearest minute */
	233	if (alrm->time.tm_sec) {
	234	time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
	235
	236	alarm_time += 60 - alrm->time.tm_sec;
	237	rtc_time64_to_tm(alarm_time, &alrm->time);
	238	}
	239
9d1fa4c3	240	mutex_lock(&rv8803->flags_lock);
1e3929ef AB	241
	242	ret = i2c_smbus_read_i2c_block_data(client, RV8803_FLAG, 2, ctrl);
	243	if (ret != 2) {
9d1fa4c3	244	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	245	return ret < 0 ? ret : -EIO;
	246	}
	247
	248	alarmvals[0] = bin2bcd(alrm->time.tm_min);
	249	alarmvals[1] = bin2bcd(alrm->time.tm_hour);
	250	alarmvals[2] = bin2bcd(alrm->time.tm_mday);
	251
	252	if (rv8803->ctrl & (RV8803_CTRL_AIE \| RV8803_CTRL_UIE)) {
	253	rv8803->ctrl &= ~(RV8803_CTRL_AIE \| RV8803_CTRL_UIE);
	254	err = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL,
	255	rv8803->ctrl);
	256	if (err) {
9d1fa4c3	257	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	258	return err;
	259	}
	260	}
	261
	262	ctrl[1] &= ~RV8803_FLAG_AF;
	263	err = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG, ctrl[1]);
9d1fa4c3	264	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	265	if (err)
	266	return err;
	267
	268	err = i2c_smbus_write_i2c_block_data(rv8803->client, RV8803_ALARM_MIN,
	269	3, alarmvals);
	270	if (err)
	271	return err;
	272
	273	if (alrm->enabled) {
	274	if (rv8803->rtc->uie_rtctimer.enabled)
	275	rv8803->ctrl \|= RV8803_CTRL_UIE;
	276	if (rv8803->rtc->aie_timer.enabled)
	277	rv8803->ctrl \|= RV8803_CTRL_AIE;
	278
	279	err = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL,
	280	rv8803->ctrl);
	281	if (err)
	282	return err;
	283	}
	284
	285	return 0;
	286	}
	287
	288	static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled)
	289	{
	290	struct i2c_client *client = to_i2c_client(dev);
	291	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
	292	int ctrl, flags, err;
1e3929ef AB	293
	294	ctrl = rv8803->ctrl;
	295
	296	if (enabled) {
	297	if (rv8803->rtc->uie_rtctimer.enabled)
	298	ctrl \|= RV8803_CTRL_UIE;
	299	if (rv8803->rtc->aie_timer.enabled)
	300	ctrl \|= RV8803_CTRL_AIE;
	301	} else {
	302	if (!rv8803->rtc->uie_rtctimer.enabled)
	303	ctrl &= ~RV8803_CTRL_UIE;
	304	if (!rv8803->rtc->aie_timer.enabled)
	305	ctrl &= ~RV8803_CTRL_AIE;
	306	}
	307
9d1fa4c3	308	mutex_lock(&rv8803->flags_lock);
1e3929ef AB	309	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
1e3929ef AB	310	if (flags < 0) {
9d1fa4c3	311	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	312	return flags;
	313	}
	314	flags &= ~(RV8803_FLAG_AF \| RV8803_FLAG_UF);
	315	err = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
9d1fa4c3	316	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	317	if (err)
	318	return err;
	319
	320	if (ctrl != rv8803->ctrl) {
	321	rv8803->ctrl = ctrl;
	322	err = i2c_smbus_write_byte_data(client, RV8803_CTRL,
	323	rv8803->ctrl);
	324	if (err)
	325	return err;
	326	}
	327
	328	return 0;
	329	}
	330
	331	static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
	332	{
	333	struct i2c_client *client = to_i2c_client(dev);
	334	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
	335	int flags, ret = 0;
1e3929ef AB	336
	337	switch (cmd) {
	338	case RTC_VL_READ:
	339	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
	340	if (flags < 0)
	341	return flags;
	342
	343	if (flags & RV8803_FLAG_V1F)
	344	dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
	345
	346	if (flags & RV8803_FLAG_V2F)
	347	dev_warn(&client->dev, "Voltage low, data loss detected.\n");
	348
	349	flags &= RV8803_FLAG_V1F \| RV8803_FLAG_V2F;
	350
	351	if (copy_to_user((void __user *)arg, &flags, sizeof(int)))
	352	return -EFAULT;
	353
	354	return 0;
	355
	356	case RTC_VL_CLR:
9d1fa4c3	357	mutex_lock(&rv8803->flags_lock);
1e3929ef AB	358	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
1e3929ef AB	359	if (flags < 0) {
9d1fa4c3	360	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	361	return flags;
	362	}
	363
	364	flags &= ~(RV8803_FLAG_V1F \| RV8803_FLAG_V2F);
	365	ret = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
9d1fa4c3	366	mutex_unlock(&rv8803->flags_lock);
1e3929ef AB	367	if (ret < 0)
	368	return ret;
	369
	370	return 0;
	371
	372	default:
	373	return -ENOIOCTLCMD;
	374	}
	375	}
	376
	377	static ssize_t rv8803_nvram_write(struct file filp, struct kobject kobj,
	378	struct bin_attribute *attr,
	379	char *buf, loff_t off, size_t count)
	380	{
	381	struct device *dev = kobj_to_dev(kobj);
	382	struct i2c_client *client = to_i2c_client(dev);
	383	int ret;
	384
	385	ret = i2c_smbus_write_byte_data(client, RV8803_RAM, buf[0]);
	386	if (ret < 0)
	387	return ret;
	388
	389	return 1;
	390	}
	391
	392	static ssize_t rv8803_nvram_read(struct file filp, struct kobject kobj,
	393	struct bin_attribute *attr,
	394	char *buf, loff_t off, size_t count)
	395	{
	396	struct device *dev = kobj_to_dev(kobj);
	397	struct i2c_client *client = to_i2c_client(dev);
	398	int ret;
	399
	400	ret = i2c_smbus_read_byte_data(client, RV8803_RAM);
	401	if (ret < 0)
	402	return ret;
	403
	404	buf[0] = ret;
	405
	406	return 1;
	407	}
	408
	409	static struct bin_attribute rv8803_nvram_attr = {
	410	.attr = {
	411	.name = "nvram",
	412	.mode = S_IRUGO \| S_IWUSR,
	413	},
	414	.size = 1,
	415	.read = rv8803_nvram_read,
	416	.write = rv8803_nvram_write,
	417	};
	418
	419	static struct rtc_class_ops rv8803_rtc_ops = {
	420	.read_time = rv8803_get_time,
	421	.set_time = rv8803_set_time,
	422	.ioctl = rv8803_ioctl,
	423	};
	424
	425	static int rv8803_probe(struct i2c_client *client,
	426	const struct i2c_device_id *id)
	427	{
	428	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
	429	struct rv8803_data *rv8803;
85062c9b	430	int err, flags, try = 0;
1e3929ef AB	431
	432	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA \|
	433	I2C_FUNC_SMBUS_I2C_BLOCK)) {
	434	dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA \| I2C_FUNC_SMBUS_I2C_BLOCK\n");
	435	return -EIO;
	436	}
	437
	438	rv8803 = devm_kzalloc(&client->dev, sizeof(struct rv8803_data),
	439	GFP_KERNEL);
	440	if (!rv8803)
	441	return -ENOMEM;
	442
9d1fa4c3	443	mutex_init(&rv8803->flags_lock);
1e3929ef AB	444	rv8803->client = client;
	445	i2c_set_clientdata(client, rv8803);
	446
85062c9b AB	447	/*
	448	* There is a 60µs window where the RTC may not reply on the i2c bus in
	449	* that case, the transfer is not ACKed. In that case, ensure there are
	450	* multiple attempts.
	451	*/
	452	do {
	453	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
	454	try++;
	455	} while ((flags == -ENXIO) && (try < 3));
	456
1e3929ef AB	457	if (flags < 0)
	458	return flags;
	459
	460	if (flags & RV8803_FLAG_V1F)
	461	dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
	462
	463	if (flags & RV8803_FLAG_V2F)
	464	dev_warn(&client->dev, "Voltage low, data loss detected.\n");
	465
	466	if (flags & RV8803_FLAG_AF)
	467	dev_warn(&client->dev, "An alarm maybe have been missed.\n");
	468
	469	if (client->irq > 0) {
	470	err = devm_request_threaded_irq(&client->dev, client->irq,
	471	NULL, rv8803_handle_irq,
	472	IRQF_TRIGGER_LOW \| IRQF_ONESHOT,
	473	"rv8803", client);
	474	if (err) {
	475	dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
	476	client->irq = 0;
	477	} else {
	478	rv8803_rtc_ops.read_alarm = rv8803_get_alarm;
	479	rv8803_rtc_ops.set_alarm = rv8803_set_alarm;
	480	rv8803_rtc_ops.alarm_irq_enable = rv8803_alarm_irq_enable;
	481	}
	482	}
	483
	484	rv8803->rtc = devm_rtc_device_register(&client->dev, client->name,
	485	&rv8803_rtc_ops, THIS_MODULE);
	486	if (IS_ERR(rv8803->rtc)) {
	487	dev_err(&client->dev, "unable to register the class device\n");
	488	return PTR_ERR(rv8803->rtc);
	489	}
	490
85062c9b AB	491	try = 0;
	492	do {
	493	err = i2c_smbus_write_byte_data(rv8803->client, RV8803_EXT,
	494	RV8803_EXT_WADA);
	495	try++;
	496	} while ((err == -ENXIO) && (try < 3));
1e3929ef AB	497	if (err)
	498	return err;
	499
	500	err = device_create_bin_file(&client->dev, &rv8803_nvram_attr);
	501	if (err)
	502	return err;
	503
	504	rv8803->rtc->max_user_freq = 1;
	505
	506	return 0;
	507	}
	508
	509	static int rv8803_remove(struct i2c_client *client)
	510	{
	511	device_remove_bin_file(&client->dev, &rv8803_nvram_attr);
	512
	513	return 0;
	514	}
	515
	516	static const struct i2c_device_id rv8803_id[] = {
	517	{ "rv8803", 0 },
78ef5f2d	518	{ "rx8900", 0 },
1e3929ef AB	519	{ }
	520	};
	521	MODULE_DEVICE_TABLE(i2c, rv8803_id);
	522
	523	static struct i2c_driver rv8803_driver = {
	524	.driver = {
	525	.name = "rtc-rv8803",
	526	},
	527	.probe = rv8803_probe,
	528	.remove = rv8803_remove,
	529	.id_table = rv8803_id,
	530	};
	531	module_i2c_driver(rv8803_driver);
	532
	533	MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
	534	MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver");
	535	MODULE_LICENSE("GPL v2");