Commit 3c2b9075 authored by Wolfgang Grandegger's avatar Wolfgang Grandegger Committed by Linus Torvalds
Browse files

rtc: add stand-alone driver for RX8025 chip 



Add support for the Epson RX-8025SA/NB RTC chips.  It includes support for
alarms, periodic interrupts (1 Hz) and clock precision adjustment.

For clock precision adjustment, the SYSFS file "clock_adjust_ppb" gets
created in "/sys/class/rtc/rtcX/device".  It permits to set and get the
clock adjustment in ppb (parts per billion), e.g.:

  # echo -183000 > /sys/class/rtc/rtc0/device/clock_adjust_ppb
  # cat /sys/class/rtc/rtc0/device/clock_adjust_ppb
  -183000

This allows to compensate temperature dependent clock drifts.  According
to the RX8025 SA/NB application manual the frequency and temperature
characteristics can be approximated using the following equation:

  df = a * (ut - t)**2

  df: Frequency deviation in any temperature
  a : Coefficient = (-35 +-5) * 10**-9
  ut: Ultimate temperature in degree = +25 +-5 degree
  t : Any temperature in degree

Signed-off-by: default avatarWolfgang Grandegger <wg@grandegger.com>
Signed-off-by: default avatarSergei Poselenov <sposelenov@emcraft.com>
Signed-off-by: default avatarYuri Tikhonov <yur@emcraft.com>
Signed-off-by: default avatarDmitry Rakhchev <rda@emcraft.com>
Signed-off-by: default avatarMatthias Fuchs <matthias.fuchs@esd.eu>
Acked-by: default avatarJean Delvare <khali@linux-fr.org>
Signed-off-by: default avatarAlessandro Zummo <a.zummo@towertech.it>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 97f902b7

drivers/rtc/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -296,6 +296,15 @@ config RTC_DRV_RX8581 
	  This driver can also be built as a module. If so the module

	  will be called rtc-rx8581.



config RTC_DRV_RX8025

	tristate "Epson RX-8025SA/NB"

	help

	  If you say yes here you get support for the Epson

	  RX-8025SA/NB RTC chips.



	  This driver can also be built as a module. If so, the module

	  will be called rtc-rx8025.



endif # I2C



comment "SPI RTC drivers"

drivers/rtc/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -62,6 +62,7 @@ obj-$(CONFIG_RTC_DRV_R9701) += rtc-r9701.o 
obj-$(CONFIG_RTC_DRV_RS5C313)	+= rtc-rs5c313.o

obj-$(CONFIG_RTC_DRV_RS5C348)	+= rtc-rs5c348.o

obj-$(CONFIG_RTC_DRV_RS5C372)	+= rtc-rs5c372.o

obj-$(CONFIG_RTC_DRV_RX8025)	+= rtc-rx8025.o

obj-$(CONFIG_RTC_DRV_RX8581)	+= rtc-rx8581.o

obj-$(CONFIG_RTC_DRV_S35390A)	+= rtc-s35390a.o

obj-$(CONFIG_RTC_DRV_S3C)	+= rtc-s3c.o

drivers/rtc/rtc-rx8025.c

0 → 100644
+688 −0
Original line number Diff line number Diff line 
/*

 * Driver for Epson's RTC module RX-8025 SA/NB

 *

 * Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com>

 *

 * Copyright (C) 2005 by Digi International Inc.

 * All rights reserved.

 *

 * Modified by fengjh at rising.com.cn

 * <http://lists.lm-sensors.org/mailman/listinfo/lm-sensors>

 * 2006.11

 *

 * Code cleanup by Sergei Poselenov, <sposelenov@emcraft.com>

 * Converted to new style by Wolfgang Grandegger <wg@grandegger.com>

 * Alarm and periodic interrupt added by Dmitry Rakhchev <rda@emcraft.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/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/bcd.h>

#include <linux/i2c.h>

#include <linux/list.h>

#include <linux/rtc.h>



/* Register definitions */

#define RX8025_REG_SEC		0x00

#define RX8025_REG_MIN		0x01

#define RX8025_REG_HOUR		0x02

#define RX8025_REG_WDAY		0x03

#define RX8025_REG_MDAY		0x04

#define RX8025_REG_MONTH	0x05

#define RX8025_REG_YEAR		0x06

#define RX8025_REG_DIGOFF	0x07

#define RX8025_REG_ALWMIN	0x08

#define RX8025_REG_ALWHOUR	0x09

#define RX8025_REG_ALWWDAY	0x0a

#define RX8025_REG_ALDMIN	0x0b

#define RX8025_REG_ALDHOUR	0x0c

/* 0x0d is reserved */

#define RX8025_REG_CTRL1	0x0e

#define RX8025_REG_CTRL2	0x0f



#define RX8025_BIT_CTRL1_CT	(7 << 0)

/* 1 Hz periodic level irq */

#define RX8025_BIT_CTRL1_CT_1HZ	4

#define RX8025_BIT_CTRL1_TEST	(1 << 3)

#define RX8025_BIT_CTRL1_1224	(1 << 5)

#define RX8025_BIT_CTRL1_DALE	(1 << 6)

#define RX8025_BIT_CTRL1_WALE	(1 << 7)



#define RX8025_BIT_CTRL2_DAFG	(1 << 0)

#define RX8025_BIT_CTRL2_WAFG	(1 << 1)

#define RX8025_BIT_CTRL2_CTFG	(1 << 2)

#define RX8025_BIT_CTRL2_PON	(1 << 4)

#define RX8025_BIT_CTRL2_XST	(1 << 5)

#define RX8025_BIT_CTRL2_VDET	(1 << 6)



/* Clock precision adjustment */

#define RX8025_ADJ_RESOLUTION	3050 /* in ppb */

#define RX8025_ADJ_DATA_MAX	62

#define RX8025_ADJ_DATA_MIN	-62



static const struct i2c_device_id rx8025_id[] = {

	{ "rx8025", 0 },

	{ }

};

MODULE_DEVICE_TABLE(i2c, rx8025_id);



struct rx8025_data {

	struct i2c_client *client;

	struct rtc_device *rtc;

	struct work_struct work;

	u8 ctrl1;

	unsigned exiting:1;

};



static int rx8025_read_reg(struct i2c_client *client, int number, u8 *value)

{

	int ret = i2c_smbus_read_byte_data(client, (number << 4) | 0x08);



	if (ret < 0) {

		dev_err(&client->dev, "Unable to read register #%d\n", number);

		return ret;

	}



	*value = ret;

	return 0;

}



static int rx8025_read_regs(struct i2c_client *client,

			    int number, u8 length, u8 *values)

{

	int ret = i2c_smbus_read_i2c_block_data(client, (number << 4) | 0x08,

						length, values);



	if (ret != length) {

		dev_err(&client->dev, "Unable to read registers #%d..#%d\n",

			number, number + length - 1);

		return ret < 0 ? ret : -EIO;

	}



	return 0;

}



static int rx8025_write_reg(struct i2c_client *client, int number, u8 value)

{

	int ret = i2c_smbus_write_byte_data(client, number << 4, value);



	if (ret)

		dev_err(&client->dev, "Unable to write register #%d\n",

			number);



	return ret;

}



static int rx8025_write_regs(struct i2c_client *client,

			     int number, u8 length, u8 *values)

{

	int ret = i2c_smbus_write_i2c_block_data(client, (number << 4) | 0x08,

						 length, values);



	if (ret)

		dev_err(&client->dev, "Unable to write registers #%d..#%d\n",

			number, number + length - 1);



	return ret;

}



static irqreturn_t rx8025_irq(int irq, void *dev_id)

{

	struct i2c_client *client = dev_id;

	struct rx8025_data *rx8025 = i2c_get_clientdata(client);



	disable_irq_nosync(irq);

	schedule_work(&rx8025->work);

	return IRQ_HANDLED;

}



static void rx8025_work(struct work_struct *work)

{

	struct rx8025_data *rx8025 = container_of(work, struct rx8025_data,

						  work);

	struct i2c_client *client = rx8025->client;

	struct mutex *lock = &rx8025->rtc->ops_lock;

	u8 status;



	mutex_lock(lock);



	if (rx8025_read_reg(client, RX8025_REG_CTRL2, &status))

		goto out;



	if (!(status & RX8025_BIT_CTRL2_XST))

		dev_warn(&client->dev, "Oscillation stop was detected,"

			 "you may have to readjust the clock\n");



	if (status & RX8025_BIT_CTRL2_CTFG) {

		/* periodic */

		status &= ~RX8025_BIT_CTRL2_CTFG;

		local_irq_disable();

		rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);

		local_irq_enable();

	}



	if (status & RX8025_BIT_CTRL2_DAFG) {

		/* alarm */

		status &= RX8025_BIT_CTRL2_DAFG;

		if (rx8025_write_reg(client, RX8025_REG_CTRL1,

				     rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))

			goto out;

		local_irq_disable();

		rtc_update_irq(rx8025->rtc, 1, RTC_AF | RTC_IRQF);

		local_irq_enable();

	}



	/* acknowledge IRQ */

	rx8025_write_reg(client, RX8025_REG_CTRL2,

			 status | RX8025_BIT_CTRL2_XST);



out:

	if (!rx8025->exiting)

		enable_irq(client->irq);



	mutex_unlock(lock);

}



static int rx8025_get_time(struct device *dev, struct rtc_time *dt)

{

	struct rx8025_data *rx8025 = dev_get_drvdata(dev);

	u8 date[7];

	int err;



	err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);

	if (err)

		return err;



	dev_dbg(dev, "%s: read 0x%02x 0x%02x "

		"0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,

		date[0], date[1], date[2], date[3], date[4],

		date[5], date[6]);



	dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);

	dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);

	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)

		dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);

	else

		dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12

			+ (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);



	dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);

	dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;

	dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]);



	if (dt->tm_year < 70)

		dt->tm_year += 100;



	dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,

		dt->tm_sec, dt->tm_min, dt->tm_hour,

		dt->tm_mday, dt->tm_mon, dt->tm_year);



	return rtc_valid_tm(dt);

}



static int rx8025_set_time(struct device *dev, struct rtc_time *dt)

{

	struct rx8025_data *rx8025 = dev_get_drvdata(dev);

	u8 date[7];



	/*

	 * BUG: The HW assumes every year that is a multiple of 4 to be a leap

	 * year.  Next time this is wrong is 2100, which will not be a leap

	 * year.

	 */



	/*

	 * Here the read-only bits are written as "0".  I'm not sure if that

	 * is sound.

	 */

	date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);

	date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);

	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)

		date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);

	else

		date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)

			| bin2bcd((dt->tm_hour + 11) % 12 + 1);



	date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);

	date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);

	date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);

	date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year % 100);



	dev_dbg(dev,

		"%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",

		__func__,

		date[0], date[1], date[2], date[3], date[4], date[5], date[6]);



	return rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);

}



static int rx8025_init_client(struct i2c_client *client, int *need_reset)

{

	struct rx8025_data *rx8025 = i2c_get_clientdata(client);

	u8 ctrl[2], ctrl2;

	int need_clear = 0;

	int err;



	err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);

	if (err)

		goto out;



	/* Keep test bit zero ! */

	rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;



	if (ctrl[1] & RX8025_BIT_CTRL2_PON) {

		dev_warn(&client->dev, "power-on reset was detected, "

			 "you may have to readjust the clock\n");

		*need_reset = 1;

	}



	if (ctrl[1] & RX8025_BIT_CTRL2_VDET) {

		dev_warn(&client->dev, "a power voltage drop was detected, "

			 "you may have to readjust the clock\n");

		*need_reset = 1;

	}



	if (!(ctrl[1] & RX8025_BIT_CTRL2_XST)) {

		dev_warn(&client->dev, "Oscillation stop was detected,"

			 "you may have to readjust the clock\n");

		*need_reset = 1;

	}



	if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {

		dev_warn(&client->dev, "Alarm was detected\n");

		need_clear = 1;

	}



	if (!(ctrl[1] & RX8025_BIT_CTRL2_CTFG))

		need_clear = 1;



	if (*need_reset || need_clear) {

		ctrl2 = ctrl[0];

		ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET |

			   RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |

			   RX8025_BIT_CTRL2_DAFG);

		ctrl2 |= RX8025_BIT_CTRL2_XST;



		err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);

	}

out:

	return err;

}



/* Alarm support */

static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)

{

	struct rx8025_data *rx8025 = dev_get_drvdata(dev);

	struct i2c_client *client = rx8025->client;

	u8 ctrl2, ald[2];

	int err;



	if (client->irq <= 0)

		return -EINVAL;



	err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);

	if (err)

		return err;



	err = rx8025_read_reg(client, RX8025_REG_CTRL2, &ctrl2);

	if (err)

		return err;



	dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",

		__func__, ald[0], ald[1], ctrl2);



	/* Hardware alarms precision is 1 minute! */

	t->time.tm_sec = 0;

	t->time.tm_min = bcd2bin(ald[0] & 0x7f);

	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)

		t->time.tm_hour = bcd2bin(ald[1] & 0x3f);

	else

		t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12

			+ (ald[1] & 0x20 ? 12 : 0);



	t->time.tm_wday = -1;

	t->time.tm_mday = -1;

	t->time.tm_mon = -1;

	t->time.tm_year = -1;



	dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",

		__func__,

		t->time.tm_sec, t->time.tm_min, t->time.tm_hour,

		t->time.tm_mday, t->time.tm_mon, t->time.tm_year);

	t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);

	t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;



	return err;

}



static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct rx8025_data *rx8025 = dev_get_drvdata(dev);

	u8 ald[2];

	int err;



	if (client->irq <= 0)

		return -EINVAL;



	/* Hardware alarm precision is 1 minute! */

	ald[0] = bin2bcd(t->time.tm_min);

	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)

		ald[1] = bin2bcd(t->time.tm_hour);

	else

		ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)

			| bin2bcd((t->time.tm_hour + 11) % 12 + 1);



	dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);



	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {

		rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;

		err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,

				       rx8025->ctrl1);

		if (err)

			return err;

	}

	err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);

	if (err)

		return err;



	if (t->enabled) {

		rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;

		err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,

				       rx8025->ctrl1);

		if (err)

			return err;

	}



	return 0;

}



static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)

{

	struct rx8025_data *rx8025 = dev_get_drvdata(dev);

	u8 ctrl1;

	int err;



	ctrl1 = rx8025->ctrl1;

	if (enabled)

		ctrl1 |= RX8025_BIT_CTRL1_DALE;

	else

		ctrl1 &= ~RX8025_BIT_CTRL1_DALE;



	if (ctrl1 != rx8025->ctrl1) {

		rx8025->ctrl1 = ctrl1;

		err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,

				       rx8025->ctrl1);

		if (err)

			return err;

	}

	return 0;

}



static int rx8025_irq_set_state(struct device *dev, int enabled)

{

	struct i2c_client *client = to_i2c_client(dev);

	struct rx8025_data *rx8025 = i2c_get_clientdata(client);

	int ctrl1;

	int err;



	if (client->irq <= 0)

		return -ENXIO;



	ctrl1 = rx8025->ctrl1 & ~RX8025_BIT_CTRL1_CT;

	if (enabled)

		ctrl1 |= RX8025_BIT_CTRL1_CT_1HZ;

	if (ctrl1 != rx8025->ctrl1) {

		rx8025->ctrl1 = ctrl1;

		err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,

				       rx8025->ctrl1);

		if (err)

			return err;

	}



	return 0;

}



static struct rtc_class_ops rx8025_rtc_ops = {

	.read_time = rx8025_get_time,

	.set_time = rx8025_set_time,

	.read_alarm = rx8025_read_alarm,

	.set_alarm = rx8025_set_alarm,

	.alarm_irq_enable = rx8025_alarm_irq_enable,

	.irq_set_state  = rx8025_irq_set_state,

};



/*

 * Clock precision adjustment support

 *

 * According to the RX8025 SA/NB application manual the frequency and

 * temperature charateristics can be approximated using the following

 * equation:

 *

 *   df = a * (ut - t)**2

 *

 *   df: Frequency deviation in any temperature

 *   a : Coefficient = (-35 +-5) * 10**-9

 *   ut: Ultimate temperature in degree = +25 +-5 degree

 *   t : Any temperature in degree

 *

 * Note that the clock adjustment in ppb must be entered (which is

 * the negative value of the deviation).

 */

static int rx8025_get_clock_adjust(struct device *dev, int *adj)

{

	struct i2c_client *client = to_i2c_client(dev);

	u8 digoff;

	int err;



	err = rx8025_read_reg(client, RX8025_REG_DIGOFF, &digoff);

	if (err)

		return err;



	*adj = digoff >= 64 ? digoff - 128 : digoff;

	if (*adj > 0)

		(*adj)--;

	*adj *= -RX8025_ADJ_RESOLUTION;



	return 0;

}



static int rx8025_set_clock_adjust(struct device *dev, int adj)

{

	struct i2c_client *client = to_i2c_client(dev);

	u8 digoff;

	int err;



	adj /= -RX8025_ADJ_RESOLUTION;

	if (adj > RX8025_ADJ_DATA_MAX)

		adj = RX8025_ADJ_DATA_MAX;

	else if (adj < RX8025_ADJ_DATA_MIN)

		adj = RX8025_ADJ_DATA_MIN;

	else if (adj > 0)

		adj++;

	else if (adj < 0)

		adj += 128;

	digoff = adj;



	err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);

	if (err)

		return err;



	dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);



	return 0;

}



static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,

					      struct device_attribute *attr,

					      char *buf)

{

	int err, adj;



	err = rx8025_get_clock_adjust(dev, &adj);

	if (err)

		return err;



	return sprintf(buf, "%d\n", adj);

}



static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,

					       struct device_attribute *attr,

					       const char *buf, size_t count)

{

	int adj, err;



	if (sscanf(buf, "%i", &adj) != 1)

		return -EINVAL;



	err = rx8025_set_clock_adjust(dev, adj);



	return err ? err : count;

}



static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO | S_IWUSR,

		   rx8025_sysfs_show_clock_adjust,

		   rx8025_sysfs_store_clock_adjust);



static int rx8025_sysfs_register(struct device *dev)

{

	return device_create_file(dev, &dev_attr_clock_adjust_ppb);

}



static void rx8025_sysfs_unregister(struct device *dev)

{

	device_remove_file(dev, &dev_attr_clock_adjust_ppb);

}



static int __devinit rx8025_probe(struct i2c_client *client,

				  const struct i2c_device_id *id)

{

	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);

	struct rx8025_data *rx8025;

	int err, need_reset = 0;



	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA

				     | I2C_FUNC_SMBUS_I2C_BLOCK)) {

		dev_err(&adapter->dev,

			"doesn't support required functionality\n");

		err = -EIO;

		goto errout;

	}



	rx8025 = kzalloc(sizeof(*rx8025), GFP_KERNEL);

	if (!rx8025) {

		dev_err(&adapter->dev, "failed to alloc memory\n");

		err = -ENOMEM;

		goto errout;

	}



	rx8025->client = client;

	i2c_set_clientdata(client, rx8025);

	INIT_WORK(&rx8025->work, rx8025_work);



	err = rx8025_init_client(client, &need_reset);

	if (err)

		goto errout_free;



	if (need_reset) {

		struct rtc_time tm;

		dev_info(&client->dev,

			 "bad conditions detected, resetting date\n");

		rtc_time_to_tm(0, &tm);	/* 1970/1/1 */

		rx8025_set_time(&client->dev, &tm);

	}



	rx8025->rtc = rtc_device_register(client->name, &client->dev,

					  &rx8025_rtc_ops, THIS_MODULE);

	if (IS_ERR(rx8025->rtc)) {

		err = PTR_ERR(rx8025->rtc);

		dev_err(&client->dev, "unable to register the class device\n");

		goto errout_free;

	}



	if (client->irq > 0) {

		dev_info(&client->dev, "IRQ %d supplied\n", client->irq);

		err = request_irq(client->irq, rx8025_irq,

				  0, "rx8025", client);

		if (err) {

			dev_err(&client->dev, "unable to request IRQ\n");

			goto errout_reg;

		}

	}



	rx8025->rtc->irq_freq = 1;

	rx8025->rtc->max_user_freq = 1;



	err = rx8025_sysfs_register(&client->dev);

	if (err)

		goto errout_irq;



	return 0;



errout_irq:

	if (client->irq > 0)

		free_irq(client->irq, client);



errout_reg:

	rtc_device_unregister(rx8025->rtc);



errout_free:

	i2c_set_clientdata(client, NULL);

	kfree(rx8025);



errout:

	dev_err(&adapter->dev, "probing for rx8025 failed\n");

	return err;

}



static int __devexit rx8025_remove(struct i2c_client *client)

{

	struct rx8025_data *rx8025 = i2c_get_clientdata(client);

	struct mutex *lock = &rx8025->rtc->ops_lock;



	if (client->irq > 0) {

		mutex_lock(lock);

		rx8025->exiting = 1;

		mutex_unlock(lock);



		free_irq(client->irq, client);

		flush_scheduled_work();

	}



	rx8025_sysfs_unregister(&client->dev);

	rtc_device_unregister(rx8025->rtc);

	i2c_set_clientdata(client, NULL);

	kfree(rx8025);

	return 0;

}



static struct i2c_driver rx8025_driver = {

	.driver = {

		.name = "rtc-rx8025",

		.owner = THIS_MODULE,

	},

	.probe		= rx8025_probe,

	.remove		= __devexit_p(rx8025_remove),

	.id_table	= rx8025_id,

};



static int __init rx8025_init(void)

{

	return i2c_add_driver(&rx8025_driver);

}



static void __exit rx8025_exit(void)

{

	i2c_del_driver(&rx8025_driver);

}



MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");

MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");

MODULE_LICENSE("GPL");



module_init(rx8025_init);

module_exit(rx8025_exit);

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