[linux-2.6-block.git] / drivers / rtc / rtc-rx8581.c

/*
 * An I2C driver for the Epson RX8581 RTC
 *
 * Author: Martyn Welch <martyn.welch@ge.com>
 * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc.
 *
 * 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.
 *
 * Based on: rtc-pcf8563.c (An I2C driver for the Philips PCF8563 RTC)
 * Copyright 2005-06 Tower Technologies
 */

#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/log2.h>

#define DRV_VERSION "0.1"

#define RX8581_REG_SC		0x00 /* Second in BCD */
#define RX8581_REG_MN		0x01 /* Minute in BCD */
#define RX8581_REG_HR		0x02 /* Hour in BCD */
#define RX8581_REG_DW		0x03 /* Day of Week */
#define RX8581_REG_DM		0x04 /* Day of Month in BCD */
#define RX8581_REG_MO		0x05 /* Month in BCD */
#define RX8581_REG_YR		0x06 /* Year in BCD */
#define RX8581_REG_RAM		0x07 /* RAM */
#define RX8581_REG_AMN		0x08 /* Alarm Min in BCD*/
#define RX8581_REG_AHR		0x09 /* Alarm Hour in BCD */
#define RX8581_REG_ADM		0x0A
#define RX8581_REG_ADW		0x0A
#define RX8581_REG_TMR0		0x0B
#define RX8581_REG_TMR1		0x0C
#define RX8581_REG_EXT		0x0D /* Extension Register */
#define RX8581_REG_FLAG		0x0E /* Flag Register */
#define RX8581_REG_CTRL		0x0F /* Control Register */


/* Flag Register bit definitions */
#define RX8581_FLAG_UF		0x20 /* Update */
#define RX8581_FLAG_TF		0x10 /* Timer */
#define RX8581_FLAG_AF		0x08 /* Alarm */
#define RX8581_FLAG_VLF		0x02 /* Voltage Low */

/* Control Register bit definitions */
#define RX8581_CTRL_UIE		0x20 /* Update Interrupt Enable */
#define RX8581_CTRL_TIE		0x10 /* Timer Interrupt Enable */
#define RX8581_CTRL_AIE		0x08 /* Alarm Interrupt Enable */
#define RX8581_CTRL_STOP	0x02 /* STOP bit */
#define RX8581_CTRL_RESET	0x01 /* RESET bit */

struct rx8581 {
	struct i2c_client	*client;
	struct rtc_device	*rtc;
	s32 (*read_block_data)(const struct i2c_client *client, u8 command,
				u8 length, u8 *values);
	s32 (*write_block_data)(const struct i2c_client *client, u8 command,
				u8 length, const u8 *values);
};

static struct i2c_driver rx8581_driver;

static int rx8581_read_block_data(const struct i2c_client *client, u8 command,
					u8 length, u8 *values)
{
	s32 i, data;

	for (i = 0; i < length; i++) {
		data = i2c_smbus_read_byte_data(client, command + i);
		if (data < 0)
			return data;
		values[i] = data;
	}
	return i;
}

static int rx8581_write_block_data(const struct i2c_client *client, u8 command,
					u8 length, const u8 *values)
{
	s32 i, ret;

	for (i = 0; i < length; i++) {
		ret = i2c_smbus_write_byte_data(client, command + i,
						values[i]);
		if (ret < 0)
			return ret;
	}
	return length;
}

/*
 * In the routines that deal directly with the rx8581 hardware, we use
 * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
 */
static int rx8581_get_datetime(struct i2c_client *client, struct rtc_time *tm)
{
	unsigned char date[7];
	int data, err;
	struct rx8581 *rx8581 = i2c_get_clientdata(client);

	/* First we ensure that the "update flag" is not set, we read the
	 * time and date then re-read the "update flag". If the update flag
	 * has been set, we know that the time has changed during the read so
	 * we repeat the whole process again.
	 */
	data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
	if (data < 0) {
		dev_err(&client->dev, "Unable to read device flags\n");
		return -EIO;
	}

	do {
		/* If update flag set, clear it */
		if (data & RX8581_FLAG_UF) {
			err = i2c_smbus_write_byte_data(client,
				RX8581_REG_FLAG, (data & ~RX8581_FLAG_UF));
			if (err != 0) {
				dev_err(&client->dev, "Unable to write device flags\n");
				return -EIO;
			}
		}

		/* Now read time and date */
		err = rx8581->read_block_data(client, RX8581_REG_SC,
			7, date);
		if (err < 0) {
			dev_err(&client->dev, "Unable to read date\n");
			return -EIO;
		}

		/* Check flag register */
		data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
		if (data < 0) {
			dev_err(&client->dev, "Unable to read device flags\n");
			return -EIO;
		}
	} while (data & RX8581_FLAG_UF);

	if (data & RX8581_FLAG_VLF)
		dev_info(&client->dev,
			"low voltage detected, date/time is not reliable.\n");

	dev_dbg(&client->dev,
		"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
		"wday=%02x, mday=%02x, mon=%02x, year=%02x\n",
		__func__,
		date[0], date[1], date[2], date[3], date[4], date[5], date[6]);

	tm->tm_sec = bcd2bin(date[RX8581_REG_SC] & 0x7F);
	tm->tm_min = bcd2bin(date[RX8581_REG_MN] & 0x7F);
	tm->tm_hour = bcd2bin(date[RX8581_REG_HR] & 0x3F); /* rtc hr 0-23 */
	tm->tm_wday = ilog2(date[RX8581_REG_DW] & 0x7F);
	tm->tm_mday = bcd2bin(date[RX8581_REG_DM] & 0x3F);
	tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
	tm->tm_year = bcd2bin(date[RX8581_REG_YR]);
	if (tm->tm_year < 70)
		tm->tm_year += 100;	/* assume we are in 1970...2069 */


	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
		"mday=%d, mon=%d, year=%d, wday=%d\n",
		__func__,
		tm->tm_sec, tm->tm_min, tm->tm_hour,
		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

	err = rtc_valid_tm(tm);
	if (err < 0)
		dev_err(&client->dev, "retrieved date/time is not valid.\n");

	return err;
}

static int rx8581_set_datetime(struct i2c_client *client, struct rtc_time *tm)
{
	int data, err;
	unsigned char buf[7];
	struct rx8581 *rx8581 = i2c_get_clientdata(client);

	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
		"mday=%d, mon=%d, year=%d, wday=%d\n",
		__func__,
		tm->tm_sec, tm->tm_min, tm->tm_hour,
		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

	/* hours, minutes and seconds */
	buf[RX8581_REG_SC] = bin2bcd(tm->tm_sec);
	buf[RX8581_REG_MN] = bin2bcd(tm->tm_min);
	buf[RX8581_REG_HR] = bin2bcd(tm->tm_hour);

	buf[RX8581_REG_DM] = bin2bcd(tm->tm_mday);

	/* month, 1 - 12 */
	buf[RX8581_REG_MO] = bin2bcd(tm->tm_mon + 1);

	/* year and century */
	buf[RX8581_REG_YR] = bin2bcd(tm->tm_year % 100);
	buf[RX8581_REG_DW] = (0x1 << tm->tm_wday);

	/* Stop the clock */
	data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
	if (data < 0) {
		dev_err(&client->dev, "Unable to read control register\n");
		return -EIO;
	}

	err = i2c_smbus_write_byte_data(client, RX8581_REG_CTRL,
		(data | RX8581_CTRL_STOP));
	if (err < 0) {
		dev_err(&client->dev, "Unable to write control register\n");
		return -EIO;
	}

	/* write register's data */
	err = rx8581->write_block_data(client, RX8581_REG_SC, 7, buf);
	if (err < 0) {
		dev_err(&client->dev, "Unable to write to date registers\n");
		return -EIO;
	}

	/* get VLF and clear it */
	data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
	if (data < 0) {
		dev_err(&client->dev, "Unable to read flag register\n");
		return -EIO;
	}

	err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG,
		(data & ~(RX8581_FLAG_VLF)));
	if (err != 0) {
		dev_err(&client->dev, "Unable to write flag register\n");
		return -EIO;
	}

	/* Restart the clock */
	data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
	if (data < 0) {
		dev_err(&client->dev, "Unable to read control register\n");
		return -EIO;
	}

	err = i2c_smbus_write_byte_data(client, RX8581_REG_CTRL,
		(data & ~(RX8581_CTRL_STOP)));
	if (err != 0) {
		dev_err(&client->dev, "Unable to write control register\n");
		return -EIO;
	}

	return 0;
}

static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	return rx8581_get_datetime(to_i2c_client(dev), tm);
}

static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	return rx8581_set_datetime(to_i2c_client(dev), tm);
}

static const struct rtc_class_ops rx8581_rtc_ops = {
	.read_time	= rx8581_rtc_read_time,
	.set_time	= rx8581_rtc_set_time,
};

static int rx8581_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct rx8581	  *rx8581;

	dev_dbg(&client->dev, "%s\n", __func__);

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)
		&& !i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
		return -EIO;

	rx8581 = devm_kzalloc(&client->dev, sizeof(struct rx8581), GFP_KERNEL);
	if (!rx8581)
		return -ENOMEM;

	i2c_set_clientdata(client, rx8581);
	rx8581->client = client;

	if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
		rx8581->read_block_data = i2c_smbus_read_i2c_block_data;
		rx8581->write_block_data = i2c_smbus_write_i2c_block_data;
	} else {
		rx8581->read_block_data = rx8581_read_block_data;
		rx8581->write_block_data = rx8581_write_block_data;
	}

	dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");

	rx8581->rtc = devm_rtc_device_register(&client->dev,
		rx8581_driver.driver.name, &rx8581_rtc_ops, THIS_MODULE);

	if (IS_ERR(rx8581->rtc)) {
		dev_err(&client->dev,
			"unable to register the class device\n");
		return PTR_ERR(rx8581->rtc);
	}

	return 0;
}

static const struct i2c_device_id rx8581_id[] = {
	{ "rx8581", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, rx8581_id);

static struct i2c_driver rx8581_driver = {
	.driver		= {
		.name	= "rtc-rx8581",
	},
	.probe		= rx8581_probe,
	.id_table	= rx8581_id,
};

module_i2c_driver(rx8581_driver);

MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>");
MODULE_DESCRIPTION("Epson RX-8581 RTC driver");
MODULE_LICENSE("GPL");
MODULE_VERSION(DRV_VERSION);
Commit	Line	Data
a7fa9851 MW	1	/*
	2	* An I2C driver for the Epson RX8581 RTC
	3	*
9756c4da MW	4	* Author: Martyn Welch <martyn.welch@ge.com>
9756c4da MW	5	* Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc.
a7fa9851 MW	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License version 2 as
	9	* published by the Free Software Foundation.
	10	*
	11	* Based on: rtc-pcf8563.c (An I2C driver for the Philips PCF8563 RTC)
	12	* Copyright 2005-06 Tower Technologies
	13	*/
	14
	15	#include <linux/module.h>
	16	#include <linux/i2c.h>
	17	#include <linux/bcd.h>
	18	#include <linux/rtc.h>
	19	#include <linux/log2.h>
	20
	21	#define DRV_VERSION "0.1"
	22
	23	#define RX8581_REG_SC 0x00 /* Second in BCD */
	24	#define RX8581_REG_MN 0x01 /* Minute in BCD */
	25	#define RX8581_REG_HR 0x02 /* Hour in BCD */
	26	#define RX8581_REG_DW 0x03 /* Day of Week */
	27	#define RX8581_REG_DM 0x04 /* Day of Month in BCD */
	28	#define RX8581_REG_MO 0x05 /* Month in BCD */
	29	#define RX8581_REG_YR 0x06 /* Year in BCD */
	30	#define RX8581_REG_RAM 0x07 /* RAM */
	31	#define RX8581_REG_AMN 0x08 /* Alarm Min in BCD*/
	32	#define RX8581_REG_AHR 0x09 /* Alarm Hour in BCD */
	33	#define RX8581_REG_ADM 0x0A
	34	#define RX8581_REG_ADW 0x0A
	35	#define RX8581_REG_TMR0 0x0B
	36	#define RX8581_REG_TMR1 0x0C
	37	#define RX8581_REG_EXT 0x0D /* Extension Register */
	38	#define RX8581_REG_FLAG 0x0E /* Flag Register */
	39	#define RX8581_REG_CTRL 0x0F /* Control Register */
	40
	41
	42	/* Flag Register bit definitions */
	43	#define RX8581_FLAG_UF 0x20 /* Update */
	44	#define RX8581_FLAG_TF 0x10 /* Timer */
	45	#define RX8581_FLAG_AF 0x08 /* Alarm */
	46	#define RX8581_FLAG_VLF 0x02 /* Voltage Low */
	47
	48	/* Control Register bit definitions */
	49	#define RX8581_CTRL_UIE 0x20 /* Update Interrupt Enable */
	50	#define RX8581_CTRL_TIE 0x10 /* Timer Interrupt Enable */
	51	#define RX8581_CTRL_AIE 0x08 /* Alarm Interrupt Enable */
	52	#define RX8581_CTRL_STOP 0x02 /* STOP bit */
	53	#define RX8581_CTRL_RESET 0x01 /* RESET bit */
	54
d643a49a AW	55	struct rx8581 {
	56	struct i2c_client *client;
	57	struct rtc_device *rtc;
	58	s32 (read_block_data)(const struct i2c_client client, u8 command,
	59	u8 length, u8 *values);
	60	s32 (write_block_data)(const struct i2c_client client, u8 command,
	61	u8 length, const u8 *values);
	62	};
	63
a7fa9851 MW	64	static struct i2c_driver rx8581_driver;
a7fa9851 MW	65
d643a49a AW	66	static int rx8581_read_block_data(const struct i2c_client *client, u8 command,
	67	u8 length, u8 *values)
	68	{
	69	s32 i, data;
	70
	71	for (i = 0; i < length; i++) {
	72	data = i2c_smbus_read_byte_data(client, command + i);
	73	if (data < 0)
	74	return data;
	75	values[i] = data;
	76	}
	77	return i;
	78	}
	79
	80	static int rx8581_write_block_data(const struct i2c_client *client, u8 command,
	81	u8 length, const u8 *values)
	82	{
	83	s32 i, ret;
	84
	85	for (i = 0; i < length; i++) {
	86	ret = i2c_smbus_write_byte_data(client, command + i,
	87	values[i]);
	88	if (ret < 0)
	89	return ret;
	90	}
	91	return length;
	92	}
	93
a7fa9851 MW	94	/*
	95	* In the routines that deal directly with the rx8581 hardware, we use
	96	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
	97	*/
	98	static int rx8581_get_datetime(struct i2c_client client, struct rtc_time tm)
	99	{
	100	unsigned char date[7];
	101	int data, err;
d643a49a	102	struct rx8581 *rx8581 = i2c_get_clientdata(client);
a7fa9851 MW	103
	104	/* First we ensure that the "update flag" is not set, we read the
	105	* time and date then re-read the "update flag". If the update flag
	106	* has been set, we know that the time has changed during the read so
	107	* we repeat the whole process again.
	108	*/
	109	data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
	110	if (data < 0) {
	111	dev_err(&client->dev, "Unable to read device flags\n");
	112	return -EIO;
	113	}
	114
	115	do {
	116	/* If update flag set, clear it */
	117	if (data & RX8581_FLAG_UF) {
	118	err = i2c_smbus_write_byte_data(client,
	119	RX8581_REG_FLAG, (data & ~RX8581_FLAG_UF));
	120	if (err != 0) {
d643a49a	121	dev_err(&client->dev, "Unable to write device flags\n");
a7fa9851 MW	122	return -EIO;
	123	}
	124	}
	125
	126	/* Now read time and date */
d643a49a	127	err = rx8581->read_block_data(client, RX8581_REG_SC,
a7fa9851 MW	128	7, date);
	129	if (err < 0) {
	130	dev_err(&client->dev, "Unable to read date\n");
	131	return -EIO;
	132	}
	133
	134	/* Check flag register */
	135	data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
	136	if (data < 0) {
	137	dev_err(&client->dev, "Unable to read device flags\n");
	138	return -EIO;
	139	}
	140	} while (data & RX8581_FLAG_UF);
	141
	142	if (data & RX8581_FLAG_VLF)
	143	dev_info(&client->dev,
	144	"low voltage detected, date/time is not reliable.\n");
	145
	146	dev_dbg(&client->dev,
	147	"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
	148	"wday=%02x, mday=%02x, mon=%02x, year=%02x\n",
	149	__func__,
	150	date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
	151
	152	tm->tm_sec = bcd2bin(date[RX8581_REG_SC] & 0x7F);
	153	tm->tm_min = bcd2bin(date[RX8581_REG_MN] & 0x7F);
	154	tm->tm_hour = bcd2bin(date[RX8581_REG_HR] & 0x3F); /* rtc hr 0-23 */
	155	tm->tm_wday = ilog2(date[RX8581_REG_DW] & 0x7F);
	156	tm->tm_mday = bcd2bin(date[RX8581_REG_DM] & 0x3F);
	157	tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
	158	tm->tm_year = bcd2bin(date[RX8581_REG_YR]);
	159	if (tm->tm_year < 70)
	160	tm->tm_year += 100; /* assume we are in 1970...2069 */
	161
	162
	163	dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, "
	164	"mday=%d, mon=%d, year=%d, wday=%d\n",
	165	__func__,
	166	tm->tm_sec, tm->tm_min, tm->tm_hour,
	167	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	168
	169	err = rtc_valid_tm(tm);
	170	if (err < 0)
	171	dev_err(&client->dev, "retrieved date/time is not valid.\n");
	172
	173	return err;
	174	}
	175
	176	static int rx8581_set_datetime(struct i2c_client client, struct rtc_time tm)
	177	{
	178	int data, err;
	179	unsigned char buf[7];
d643a49a	180	struct rx8581 *rx8581 = i2c_get_clientdata(client);
a7fa9851 MW	181
	182	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
	183	"mday=%d, mon=%d, year=%d, wday=%d\n",
	184	__func__,
	185	tm->tm_sec, tm->tm_min, tm->tm_hour,
	186	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);
	187
	188	/* hours, minutes and seconds */
	189	buf[RX8581_REG_SC] = bin2bcd(tm->tm_sec);
	190	buf[RX8581_REG_MN] = bin2bcd(tm->tm_min);
	191	buf[RX8581_REG_HR] = bin2bcd(tm->tm_hour);
	192
	193	buf[RX8581_REG_DM] = bin2bcd(tm->tm_mday);
	194
	195	/* month, 1 - 12 */
	196	buf[RX8581_REG_MO] = bin2bcd(tm->tm_mon + 1);
	197
	198	/* year and century */
	199	buf[RX8581_REG_YR] = bin2bcd(tm->tm_year % 100);
	200	buf[RX8581_REG_DW] = (0x1 << tm->tm_wday);
	201
	202	/* Stop the clock */
	203	data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
	204	if (data < 0) {
	205	dev_err(&client->dev, "Unable to read control register\n");
	206	return -EIO;
	207	}
	208
2884fce1	209	err = i2c_smbus_write_byte_data(client, RX8581_REG_CTRL,
a7fa9851 MW	210	(data \| RX8581_CTRL_STOP));
	211	if (err < 0) {
	212	dev_err(&client->dev, "Unable to write control register\n");
	213	return -EIO;
	214	}
	215
	216	/* write register's data */
d643a49a	217	err = rx8581->write_block_data(client, RX8581_REG_SC, 7, buf);
a7fa9851 MW	218	if (err < 0) {
	219	dev_err(&client->dev, "Unable to write to date registers\n");
	220	return -EIO;
	221	}
	222
2884fce1 RM	223	/* get VLF and clear it */
	224	data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
	225	if (data < 0) {
	226	dev_err(&client->dev, "Unable to read flag register\n");
	227	return -EIO;
	228	}
	229
	230	err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG,
	231	(data & ~(RX8581_FLAG_VLF)));
	232	if (err != 0) {
	233	dev_err(&client->dev, "Unable to write flag register\n");
	234	return -EIO;
	235	}
	236
a7fa9851 MW	237	/* Restart the clock */
	238	data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
	239	if (data < 0) {
	240	dev_err(&client->dev, "Unable to read control register\n");
	241	return -EIO;
	242	}
	243
2884fce1 RM	244	err = i2c_smbus_write_byte_data(client, RX8581_REG_CTRL,
2884fce1 RM	245	(data & ~(RX8581_CTRL_STOP)));
a7fa9851 MW	246	if (err != 0) {
	247	dev_err(&client->dev, "Unable to write control register\n");
	248	return -EIO;
	249	}
	250
	251	return 0;
	252	}
	253
	254	static int rx8581_rtc_read_time(struct device dev, struct rtc_time tm)
	255	{
	256	return rx8581_get_datetime(to_i2c_client(dev), tm);
	257	}
	258
	259	static int rx8581_rtc_set_time(struct device dev, struct rtc_time tm)
	260	{
	261	return rx8581_set_datetime(to_i2c_client(dev), tm);
	262	}
	263
	264	static const struct rtc_class_ops rx8581_rtc_ops = {
	265	.read_time = rx8581_rtc_read_time,
	266	.set_time = rx8581_rtc_set_time,
	267	};
	268
5a167f45 GKH	269	static int rx8581_probe(struct i2c_client *client,
5a167f45 GKH	270	const struct i2c_device_id *id)
a7fa9851	271	{
d643a49a	272	struct rx8581 *rx8581;
a7fa9851 MW	273
	274	dev_dbg(&client->dev, "%s\n", __func__);
	275
d643a49a AW	276	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA)
	277	&& !i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
	278	return -EIO;
a7fa9851	279
d643a49a AW	280	rx8581 = devm_kzalloc(&client->dev, sizeof(struct rx8581), GFP_KERNEL);
	281	if (!rx8581)
	282	return -ENOMEM;
a7fa9851	283
d643a49a AW	284	i2c_set_clientdata(client, rx8581);
d643a49a AW	285	rx8581->client = client;
a7fa9851	286
d643a49a AW	287	if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_I2C_BLOCK)) {
	288	rx8581->read_block_data = i2c_smbus_read_i2c_block_data;
	289	rx8581->write_block_data = i2c_smbus_write_i2c_block_data;
	290	} else {
	291	rx8581->read_block_data = rx8581_read_block_data;
	292	rx8581->write_block_data = rx8581_write_block_data;
	293	}
a7fa9851	294
d643a49a AW	295	dev_info(&client->dev, "chip found, driver version " DRV_VERSION "\n");
	296
	297	rx8581->rtc = devm_rtc_device_register(&client->dev,
	298	rx8581_driver.driver.name, &rx8581_rtc_ops, THIS_MODULE);
	299
	300	if (IS_ERR(rx8581->rtc)) {
	301	dev_err(&client->dev,
	302	"unable to register the class device\n");
	303	return PTR_ERR(rx8581->rtc);
	304	}
a7fa9851 MW	305
	306	return 0;
	307	}
	308
a7fa9851 MW	309	static const struct i2c_device_id rx8581_id[] = {
	310	{ "rx8581", 0 },
	311	{ }
	312	};
	313	MODULE_DEVICE_TABLE(i2c, rx8581_id);
	314
	315	static struct i2c_driver rx8581_driver = {
	316	.driver = {
	317	.name = "rtc-rx8581",
a7fa9851 MW	318	},
a7fa9851 MW	319	.probe = rx8581_probe,
a7fa9851 MW	320	.id_table = rx8581_id,
	321	};
	322
0abc9201	323	module_i2c_driver(rx8581_driver);
a7fa9851	324
9756c4da	325	MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com>");
a7fa9851 MW	326	MODULE_DESCRIPTION("Epson RX-8581 RTC driver");
	327	MODULE_LICENSE("GPL");
	328	MODULE_VERSION(DRV_VERSION);