[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;
	spinlock_t 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;
	u8 flags;

	spin_lock(&rv8803->flags_lock);

	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
	if (flags <= 0) {
		spin_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);
	}

	spin_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;
	unsigned long irqflags;

	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;

	spin_lock_irqsave(&rv8803->flags_lock, irqflags);

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

	ret = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG,
					flags & ~RV8803_FLAG_V2F);

	spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);

	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;
	unsigned long irqflags;

	/* 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);
	}

	spin_lock_irqsave(&rv8803->flags_lock, irqflags);

	ret = i2c_smbus_read_i2c_block_data(client, RV8803_FLAG, 2, ctrl);
	if (ret != 2) {
		spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
		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) {
			spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
			return err;
		}
	}

	ctrl[1] &= ~RV8803_FLAG_AF;
	err = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG, ctrl[1]);
	spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
	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;
	unsigned long irqflags;

	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;
	}

	spin_lock_irqsave(&rv8803->flags_lock, irqflags);
	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
	if (flags < 0) {
		spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
		return flags;
	}
	flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF);
	err = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
	spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
	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;
	unsigned long irqflags;

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

		flags &= ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F);
		ret = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
		spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
		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;

	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;

	rv8803->client = client;
	i2c_set_clientdata(client, rv8803);

	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");

	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);
	}

	err = i2c_smbus_write_byte_data(rv8803->client, RV8803_EXT,
					RV8803_EXT_WADA);
	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 },
	{ }
};
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;
	55	spinlock_t flags_lock;
	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;
	64	u8 flags;
65
66	spin_lock(&rv8803->flags_lock);
67
68	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
69	if (flags <= 0) {
70	spin_unlock(&rv8803->flags_lock);
71	return IRQ_NONE;
72	}
73
74	if (flags & RV8803_FLAG_V1F)
75	dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
76
77	if (flags & RV8803_FLAG_V2F)
78	dev_warn(&client->dev, "Voltage low, data loss detected.\n");
79
80	if (flags & RV8803_FLAG_TF) {
81	flags &= ~RV8803_FLAG_TF;
82	rv8803->ctrl &= ~RV8803_CTRL_TIE;
83	events \|= RTC_PF;
84	}
85
86	if (flags & RV8803_FLAG_AF) {
87	flags &= ~RV8803_FLAG_AF;
88	rv8803->ctrl &= ~RV8803_CTRL_AIE;
89	events \|= RTC_AF;
90	}
91
92	if (flags & RV8803_FLAG_UF) {
93	flags &= ~RV8803_FLAG_UF;
94	rv8803->ctrl &= ~RV8803_CTRL_UIE;
95	events \|= RTC_UF;
96	}
97
98	if (events) {
99	rtc_update_irq(rv8803->rtc, 1, events);
100	i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
101	i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL,
102	rv8803->ctrl);
103	}
104
105	spin_unlock(&rv8803->flags_lock);
106
107	return IRQ_HANDLED;
108	}
109
110	static int rv8803_get_time(struct device dev, struct rtc_time tm)
111	{
112	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
113	u8 date1[7];
114	u8 date2[7];
115	u8 *date = date1;
116	int ret, flags;
117
118	flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG);
119	if (flags < 0)
120	return flags;
121
122	if (flags & RV8803_FLAG_V2F) {
123	dev_warn(dev, "Voltage low, data is invalid.\n");
124	return -EINVAL;
125	}
126
127	ret = i2c_smbus_read_i2c_block_data(rv8803->client, RV8803_SEC,
128	7, date);
129	if (ret != 7)
130	return ret < 0 ? ret : -EIO;
131
132	if ((date1[RV8803_SEC] & 0x7f) == bin2bcd(59)) {
133	ret = i2c_smbus_read_i2c_block_data(rv8803->client, RV8803_SEC,
134	7, date2);
135	if (ret != 7)
136	return ret < 0 ? ret : -EIO;
137
138	if ((date2[RV8803_SEC] & 0x7f) != bin2bcd(59))
139	date = date2;
140	}
141
142	tm->tm_sec = bcd2bin(date[RV8803_SEC] & 0x7f);
143	tm->tm_min = bcd2bin(date[RV8803_MIN] & 0x7f);
144	tm->tm_hour = bcd2bin(date[RV8803_HOUR] & 0x3f);
145	tm->tm_wday = ffs(date[RV8803_WEEK] & 0x7f);
146	tm->tm_mday = bcd2bin(date[RV8803_DAY] & 0x3f);
147	tm->tm_mon = bcd2bin(date[RV8803_MONTH] & 0x1f) - 1;
148	tm->tm_year = bcd2bin(date[RV8803_YEAR]) + 100;
149
150	return rtc_valid_tm(tm);
151	}
152
153	static int rv8803_set_time(struct device dev, struct rtc_time tm)
154	{
155	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
156	u8 date[7];
157	int flags, ret;
158	unsigned long irqflags;
159
160	if ((tm->tm_year < 100) \|\| (tm->tm_year > 199))
161	return -EINVAL;
162
163	date[RV8803_SEC] = bin2bcd(tm->tm_sec);
164	date[RV8803_MIN] = bin2bcd(tm->tm_min);
165	date[RV8803_HOUR] = bin2bcd(tm->tm_hour);
166	date[RV8803_WEEK] = 1 << (tm->tm_wday);
167	date[RV8803_DAY] = bin2bcd(tm->tm_mday);
168	date[RV8803_MONTH] = bin2bcd(tm->tm_mon + 1);
169	date[RV8803_YEAR] = bin2bcd(tm->tm_year - 100);
170
171	ret = i2c_smbus_write_i2c_block_data(rv8803->client, RV8803_SEC,
172	7, date);
173	if (ret < 0)
174	return ret;
175
176	spin_lock_irqsave(&rv8803->flags_lock, irqflags);
177
178	flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG);
179	if (flags < 0) {
180	spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
181	return flags;
182	}
183
184	ret = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG,
185	flags & ~RV8803_FLAG_V2F);
186
187	spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
188
189	return ret;
190	}
191
192	static int rv8803_get_alarm(struct device dev, struct rtc_wkalrm alrm)
193	{
194	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
195	struct i2c_client *client = rv8803->client;
196	u8 alarmvals[3];
197	int flags, ret;
198
199	ret = i2c_smbus_read_i2c_block_data(client, RV8803_ALARM_MIN,
200	3, alarmvals);
201	if (ret != 3)
202	return ret < 0 ? ret : -EIO;
203
204	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
205	if (flags < 0)
206	return flags;
207
208	alrm->time.tm_sec = 0;
209	alrm->time.tm_min = bcd2bin(alarmvals[0] & 0x7f);
210	alrm->time.tm_hour = bcd2bin(alarmvals[1] & 0x3f);
211	alrm->time.tm_wday = -1;
212	alrm->time.tm_mday = bcd2bin(alarmvals[2] & 0x3f);
213	alrm->time.tm_mon = -1;
214	alrm->time.tm_year = -1;
215
216	alrm->enabled = !!(rv8803->ctrl & RV8803_CTRL_AIE);
217	alrm->pending = (flags & RV8803_FLAG_AF) && alrm->enabled;
218
219	return 0;
220	}
221
222	static int rv8803_set_alarm(struct device dev, struct rtc_wkalrm alrm)
223	{
224	struct i2c_client *client = to_i2c_client(dev);
225	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
226	u8 alarmvals[3];
227	u8 ctrl[2];
228	int ret, err;
229	unsigned long irqflags;
230
231	/* The alarm has no seconds, round up to nearest minute */
232	if (alrm->time.tm_sec) {
233	time64_t alarm_time = rtc_tm_to_time64(&alrm->time);
234
235	alarm_time += 60 - alrm->time.tm_sec;
236	rtc_time64_to_tm(alarm_time, &alrm->time);
237	}
238
239	spin_lock_irqsave(&rv8803->flags_lock, irqflags);
240
241	ret = i2c_smbus_read_i2c_block_data(client, RV8803_FLAG, 2, ctrl);
242	if (ret != 2) {
243	spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
244	return ret < 0 ? ret : -EIO;
245	}
246
247	alarmvals[0] = bin2bcd(alrm->time.tm_min);
248	alarmvals[1] = bin2bcd(alrm->time.tm_hour);
249	alarmvals[2] = bin2bcd(alrm->time.tm_mday);
250
251	if (rv8803->ctrl & (RV8803_CTRL_AIE \| RV8803_CTRL_UIE)) {
252	rv8803->ctrl &= ~(RV8803_CTRL_AIE \| RV8803_CTRL_UIE);
253	err = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL,
254	rv8803->ctrl);
255	if (err) {
256	spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
257	return err;
258	}
259	}
260
261	ctrl[1] &= ~RV8803_FLAG_AF;
262	err = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG, ctrl[1]);
263	spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
264	if (err)
265	return err;
266
267	err = i2c_smbus_write_i2c_block_data(rv8803->client, RV8803_ALARM_MIN,
268	3, alarmvals);
269	if (err)
270	return err;
271
272	if (alrm->enabled) {
273	if (rv8803->rtc->uie_rtctimer.enabled)
274	rv8803->ctrl \|= RV8803_CTRL_UIE;
275	if (rv8803->rtc->aie_timer.enabled)
276	rv8803->ctrl \|= RV8803_CTRL_AIE;
277
278	err = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL,
279	rv8803->ctrl);
280	if (err)
281	return err;
282	}
283
284	return 0;
285	}
286
287	static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled)
288	{
289	struct i2c_client *client = to_i2c_client(dev);
290	struct rv8803_data *rv8803 = dev_get_drvdata(dev);
291	int ctrl, flags, err;
292	unsigned long irqflags;
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
308	spin_lock_irqsave(&rv8803->flags_lock, irqflags);
309	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
310	if (flags < 0) {
311	spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
312	return flags;
313	}
314	flags &= ~(RV8803_FLAG_AF \| RV8803_FLAG_UF);
315	err = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
316	spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
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;
336	unsigned long irqflags;
337
338	switch (cmd) {
339	case RTC_VL_READ:
340	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
341	if (flags < 0)
342	return flags;
343
344	if (flags & RV8803_FLAG_V1F)
345	dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
346
347	if (flags & RV8803_FLAG_V2F)
348	dev_warn(&client->dev, "Voltage low, data loss detected.\n");
349
350	flags &= RV8803_FLAG_V1F \| RV8803_FLAG_V2F;
351
352	if (copy_to_user((void __user *)arg, &flags, sizeof(int)))
353	return -EFAULT;
354
355	return 0;
356
357	case RTC_VL_CLR:
358	spin_lock_irqsave(&rv8803->flags_lock, irqflags);
359	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
360	if (flags < 0) {
361	spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
362	return flags;
363	}
364
365	flags &= ~(RV8803_FLAG_V1F \| RV8803_FLAG_V2F);
366	ret = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags);
367	spin_unlock_irqrestore(&rv8803->flags_lock, irqflags);
368	if (ret < 0)
369	return ret;
370
371	return 0;
372
373	default:
374	return -ENOIOCTLCMD;
375	}
376	}
377
378	static ssize_t rv8803_nvram_write(struct file filp, struct kobject kobj,
379	struct bin_attribute *attr,
380	char *buf, loff_t off, size_t count)
381	{
382	struct device *dev = kobj_to_dev(kobj);
383	struct i2c_client *client = to_i2c_client(dev);
384	int ret;
385
386	ret = i2c_smbus_write_byte_data(client, RV8803_RAM, buf[0]);
387	if (ret < 0)
388	return ret;
389
390	return 1;
391	}
392
393	static ssize_t rv8803_nvram_read(struct file filp, struct kobject kobj,
394	struct bin_attribute *attr,
395	char *buf, loff_t off, size_t count)
396	{
397	struct device *dev = kobj_to_dev(kobj);
398	struct i2c_client *client = to_i2c_client(dev);
399	int ret;
400
401	ret = i2c_smbus_read_byte_data(client, RV8803_RAM);
402	if (ret < 0)
403	return ret;
404
405	buf[0] = ret;
406
407	return 1;
408	}
409
410	static struct bin_attribute rv8803_nvram_attr = {
411	.attr = {
412	.name = "nvram",
413	.mode = S_IRUGO \| S_IWUSR,
414	},
415	.size = 1,
416	.read = rv8803_nvram_read,
417	.write = rv8803_nvram_write,
418	};
419
420	static struct rtc_class_ops rv8803_rtc_ops = {
421	.read_time = rv8803_get_time,
422	.set_time = rv8803_set_time,
423	.ioctl = rv8803_ioctl,
424	};
425
426	static int rv8803_probe(struct i2c_client *client,
427	const struct i2c_device_id *id)
428	{
429	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
430	struct rv8803_data *rv8803;
431	int err, flags;
432
433	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA \|
434	I2C_FUNC_SMBUS_I2C_BLOCK)) {
435	dev_err(&adapter->dev, "doesn't support I2C_FUNC_SMBUS_BYTE_DATA \| I2C_FUNC_SMBUS_I2C_BLOCK\n");
436	return -EIO;
437	}
438
439	rv8803 = devm_kzalloc(&client->dev, sizeof(struct rv8803_data),
440	GFP_KERNEL);
441	if (!rv8803)
442	return -ENOMEM;
443
444	rv8803->client = client;
445	i2c_set_clientdata(client, rv8803);
446
447	flags = i2c_smbus_read_byte_data(client, RV8803_FLAG);
448	if (flags < 0)
449	return flags;
450
451	if (flags & RV8803_FLAG_V1F)
452	dev_warn(&client->dev, "Voltage low, temperature compensation stopped.\n");
453
454	if (flags & RV8803_FLAG_V2F)
455	dev_warn(&client->dev, "Voltage low, data loss detected.\n");
456
457	if (flags & RV8803_FLAG_AF)
458	dev_warn(&client->dev, "An alarm maybe have been missed.\n");
459
460	if (client->irq > 0) {
461	err = devm_request_threaded_irq(&client->dev, client->irq,
462	NULL, rv8803_handle_irq,
463	IRQF_TRIGGER_LOW \| IRQF_ONESHOT,
464	"rv8803", client);
465	if (err) {
466	dev_warn(&client->dev, "unable to request IRQ, alarms disabled\n");
467	client->irq = 0;
468	} else {
469	rv8803_rtc_ops.read_alarm = rv8803_get_alarm;
470	rv8803_rtc_ops.set_alarm = rv8803_set_alarm;
471	rv8803_rtc_ops.alarm_irq_enable = rv8803_alarm_irq_enable;
472	}
473	}
474
475	rv8803->rtc = devm_rtc_device_register(&client->dev, client->name,
476	&rv8803_rtc_ops, THIS_MODULE);
477	if (IS_ERR(rv8803->rtc)) {
478	dev_err(&client->dev, "unable to register the class device\n");
479	return PTR_ERR(rv8803->rtc);
480	}
481
482	err = i2c_smbus_write_byte_data(rv8803->client, RV8803_EXT,
483	RV8803_EXT_WADA);
484	if (err)
485	return err;
486
487	err = device_create_bin_file(&client->dev, &rv8803_nvram_attr);
488	if (err)
489	return err;
490
491	rv8803->rtc->max_user_freq = 1;
492
493	return 0;
494	}
495
496	static int rv8803_remove(struct i2c_client *client)
497	{
498	device_remove_bin_file(&client->dev, &rv8803_nvram_attr);
499
500	return 0;
501	}
502
503	static const struct i2c_device_id rv8803_id[] = {
504	{ "rv8803", 0 },
505	{ }
506	};
507	MODULE_DEVICE_TABLE(i2c, rv8803_id);
508
509	static struct i2c_driver rv8803_driver = {
510	.driver = {
511	.name = "rtc-rv8803",
512	},
513	.probe = rv8803_probe,
514	.remove = rv8803_remove,
515	.id_table = rv8803_id,
516	};
517	module_i2c_driver(rv8803_driver);
518
519	MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
520	MODULE_DESCRIPTION("Micro Crystal RV8803 RTC driver");
521	MODULE_LICENSE("GPL v2");