[linux.git] / drivers / rtc / rtc-rx8025.c

/*
 * Driver for Epson's RTC module RX-8025 SA/NB
 *
 * Copyright (C) 2009 Wolfgang Grandegger <[email protected]>
 *
 * 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, <[email protected]>
 * Converted to new style by Wolfgang Grandegger <[email protected]>
 * Alarm and periodic interrupt added by Dmitry Rakhchev <[email protected]>
 *
 * 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/slab.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 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,
};

/*
 * Clock precision adjustment support
 *
 * 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
 *
 * 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:
	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);
		cancel_work_sync(&rx8025->work);
	}

	rx8025_sysfs_unregister(&client->dev);
	rtc_device_unregister(rx8025->rtc);
	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,
};

module_i2c_driver(rx8025_driver);

MODULE_AUTHOR("Wolfgang Grandegger <[email protected]>");
MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
3c2b9075 WG	1	/*
	2	* Driver for Epson's RTC module RX-8025 SA/NB
	3	*
	4	* Copyright (C) 2009 Wolfgang Grandegger <[email protected]>
	5	*
	6	* Copyright (C) 2005 by Digi International Inc.
	7	* All rights reserved.
	8	*
	9	* Modified by fengjh at rising.com.cn
	10	* <http://lists.lm-sensors.org/mailman/listinfo/lm-sensors>
	11	* 2006.11
	12	*
	13	* Code cleanup by Sergei Poselenov, <[email protected]>
	14	* Converted to new style by Wolfgang Grandegger <[email protected]>
	15	* Alarm and periodic interrupt added by Dmitry Rakhchev <[email protected]>
	16	*
	17	* This program is free software; you can redistribute it and/or
	18	* modify it under the terms of the GNU General Public License
	19	* version 2 as published by the Free Software Foundation.
	20	*/
	21	#include <linux/kernel.h>
	22	#include <linux/module.h>
5a0e3ad6	23	#include <linux/slab.h>
3c2b9075 WG	24	#include <linux/init.h>
	25	#include <linux/bcd.h>
	26	#include <linux/i2c.h>
	27	#include <linux/list.h>
	28	#include <linux/rtc.h>
	29
	30	/* Register definitions */
	31	#define RX8025_REG_SEC 0x00
	32	#define RX8025_REG_MIN 0x01
	33	#define RX8025_REG_HOUR 0x02
	34	#define RX8025_REG_WDAY 0x03
	35	#define RX8025_REG_MDAY 0x04
	36	#define RX8025_REG_MONTH 0x05
	37	#define RX8025_REG_YEAR 0x06
	38	#define RX8025_REG_DIGOFF 0x07
	39	#define RX8025_REG_ALWMIN 0x08
	40	#define RX8025_REG_ALWHOUR 0x09
	41	#define RX8025_REG_ALWWDAY 0x0a
	42	#define RX8025_REG_ALDMIN 0x0b
	43	#define RX8025_REG_ALDHOUR 0x0c
	44	/* 0x0d is reserved */
	45	#define RX8025_REG_CTRL1 0x0e
	46	#define RX8025_REG_CTRL2 0x0f
	47
	48	#define RX8025_BIT_CTRL1_CT (7 << 0)
	49	/* 1 Hz periodic level irq */
	50	#define RX8025_BIT_CTRL1_CT_1HZ 4
	51	#define RX8025_BIT_CTRL1_TEST (1 << 3)
	52	#define RX8025_BIT_CTRL1_1224 (1 << 5)
	53	#define RX8025_BIT_CTRL1_DALE (1 << 6)
	54	#define RX8025_BIT_CTRL1_WALE (1 << 7)
	55
	56	#define RX8025_BIT_CTRL2_DAFG (1 << 0)
	57	#define RX8025_BIT_CTRL2_WAFG (1 << 1)
	58	#define RX8025_BIT_CTRL2_CTFG (1 << 2)
	59	#define RX8025_BIT_CTRL2_PON (1 << 4)
	60	#define RX8025_BIT_CTRL2_XST (1 << 5)
	61	#define RX8025_BIT_CTRL2_VDET (1 << 6)
	62
	63	/* Clock precision adjustment */
	64	#define RX8025_ADJ_RESOLUTION 3050 /* in ppb */
	65	#define RX8025_ADJ_DATA_MAX 62
	66	#define RX8025_ADJ_DATA_MIN -62
	67
	68	static const struct i2c_device_id rx8025_id[] = {
	69	{ "rx8025", 0 },
	70	{ }
	71	};
	72	MODULE_DEVICE_TABLE(i2c, rx8025_id);
	73
	74	struct rx8025_data {
	75	struct i2c_client *client;
	76	struct rtc_device *rtc;
	77	struct work_struct work;
	78	u8 ctrl1;
	79	unsigned exiting:1;
	80	};
	81
	82	static int rx8025_read_reg(struct i2c_client client, int number, u8 value)
	83	{
	84	int ret = i2c_smbus_read_byte_data(client, (number << 4) \| 0x08);
	85
	86	if (ret < 0) {
	87	dev_err(&client->dev, "Unable to read register #%d\n", number);
88	return ret;
89	}
90
91	*value = ret;
92	return 0;
93	}
94
95	static int rx8025_read_regs(struct i2c_client *client,
96	int number, u8 length, u8 *values)
97	{
98	int ret = i2c_smbus_read_i2c_block_data(client, (number << 4) \| 0x08,
99	length, values);
100
101	if (ret != length) {
102	dev_err(&client->dev, "Unable to read registers #%d..#%d\n",
103	number, number + length - 1);
104	return ret < 0 ? ret : -EIO;
105	}
106
107	return 0;
108	}
109
110	static int rx8025_write_reg(struct i2c_client *client, int number, u8 value)
111	{
112	int ret = i2c_smbus_write_byte_data(client, number << 4, value);
113
114	if (ret)
115	dev_err(&client->dev, "Unable to write register #%d\n",
116	number);
117
118	return ret;
119	}
120
121	static int rx8025_write_regs(struct i2c_client *client,
122	int number, u8 length, u8 *values)
123	{
124	int ret = i2c_smbus_write_i2c_block_data(client, (number << 4) \| 0x08,
125	length, values);
126
127	if (ret)
128	dev_err(&client->dev, "Unable to write registers #%d..#%d\n",
129	number, number + length - 1);
130
131	return ret;
132	}
133
134	static irqreturn_t rx8025_irq(int irq, void *dev_id)
135	{
136	struct i2c_client *client = dev_id;
137	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
138
139	disable_irq_nosync(irq);
140	schedule_work(&rx8025->work);
141	return IRQ_HANDLED;
142	}
143
144	static void rx8025_work(struct work_struct *work)
145	{
146	struct rx8025_data *rx8025 = container_of(work, struct rx8025_data,
147	work);
148	struct i2c_client *client = rx8025->client;
149	struct mutex *lock = &rx8025->rtc->ops_lock;
150	u8 status;
151
152	mutex_lock(lock);
153
154	if (rx8025_read_reg(client, RX8025_REG_CTRL2, &status))
155	goto out;
156
157	if (!(status & RX8025_BIT_CTRL2_XST))
158	dev_warn(&client->dev, "Oscillation stop was detected,"
159	"you may have to readjust the clock\n");
160
161	if (status & RX8025_BIT_CTRL2_CTFG) {
162	/* periodic */
163	status &= ~RX8025_BIT_CTRL2_CTFG;
164	local_irq_disable();
165	rtc_update_irq(rx8025->rtc, 1, RTC_PF \| RTC_IRQF);
166	local_irq_enable();
167	}
168
169	if (status & RX8025_BIT_CTRL2_DAFG) {
170	/* alarm */
171	status &= RX8025_BIT_CTRL2_DAFG;
172	if (rx8025_write_reg(client, RX8025_REG_CTRL1,
173	rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
174	goto out;
175	local_irq_disable();
176	rtc_update_irq(rx8025->rtc, 1, RTC_AF \| RTC_IRQF);
177	local_irq_enable();
178	}
179
180	/* acknowledge IRQ */
181	rx8025_write_reg(client, RX8025_REG_CTRL2,
182	status \| RX8025_BIT_CTRL2_XST);
183
184	out:
185	if (!rx8025->exiting)
186	enable_irq(client->irq);
187
188	mutex_unlock(lock);
189	}
190
191	static int rx8025_get_time(struct device dev, struct rtc_time dt)
192	{
193	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
194	u8 date[7];
195	int err;
196
197	err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
198	if (err)
199	return err;
200
201	dev_dbg(dev, "%s: read 0x%02x 0x%02x "
202	"0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
203	date[0], date[1], date[2], date[3], date[4],
204	date[5], date[6]);
205
206	dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
207	dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
208	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
209	dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
210	else
211	dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
212	+ (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
213
214	dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
215	dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
216	dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]);
217
218	if (dt->tm_year < 70)
219	dt->tm_year += 100;
220
221	dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
222	dt->tm_sec, dt->tm_min, dt->tm_hour,
223	dt->tm_mday, dt->tm_mon, dt->tm_year);
224
225	return rtc_valid_tm(dt);
226	}
227
228	static int rx8025_set_time(struct device dev, struct rtc_time dt)
229	{
230	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
231	u8 date[7];
232
233	/*
234	* BUG: The HW assumes every year that is a multiple of 4 to be a leap
235	* year. Next time this is wrong is 2100, which will not be a leap
236	* year.
237	*/
238
239	/*
240	* Here the read-only bits are written as "0". I'm not sure if that
241	* is sound.
242	*/
243	date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
244	date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
245	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
246	date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
247	else
248	date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
249	\| bin2bcd((dt->tm_hour + 11) % 12 + 1);
250
251	date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
252	date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
253	date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
254	date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year % 100);
255
256	dev_dbg(dev,
257	"%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
258	__func__,
259	date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
260
261	return rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
262	}
263
264	static int rx8025_init_client(struct i2c_client client, int need_reset)
265	{
266	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
267	u8 ctrl[2], ctrl2;
268	int need_clear = 0;
269	int err;
270
271	err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
272	if (err)
273	goto out;
274
275	/* Keep test bit zero ! */
276	rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
277
278	if (ctrl[1] & RX8025_BIT_CTRL2_PON) {
279	dev_warn(&client->dev, "power-on reset was detected, "
280	"you may have to readjust the clock\n");
281	*need_reset = 1;
282	}
283
284	if (ctrl[1] & RX8025_BIT_CTRL2_VDET) {
285	dev_warn(&client->dev, "a power voltage drop was detected, "
286	"you may have to readjust the clock\n");
287	*need_reset = 1;
288	}
289
290	if (!(ctrl[1] & RX8025_BIT_CTRL2_XST)) {
291	dev_warn(&client->dev, "Oscillation stop was detected,"
292	"you may have to readjust the clock\n");
293	*need_reset = 1;
294	}
295
296	if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG \| RX8025_BIT_CTRL2_WAFG)) {
297	dev_warn(&client->dev, "Alarm was detected\n");
298	need_clear = 1;
299	}
300
301	if (!(ctrl[1] & RX8025_BIT_CTRL2_CTFG))
302	need_clear = 1;
303
304	if (*need_reset \|\| need_clear) {
305	ctrl2 = ctrl[0];
306	ctrl2 &= ~(RX8025_BIT_CTRL2_PON \| RX8025_BIT_CTRL2_VDET \|
307	RX8025_BIT_CTRL2_CTFG \| RX8025_BIT_CTRL2_WAFG \|
308	RX8025_BIT_CTRL2_DAFG);
309	ctrl2 \|= RX8025_BIT_CTRL2_XST;
310
311	err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
312	}
313	out:
314	return err;
315	}
316
317	/* Alarm support */
318	static int rx8025_read_alarm(struct device dev, struct rtc_wkalrm t)
319	{
320	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
321	struct i2c_client *client = rx8025->client;
322	u8 ctrl2, ald[2];
323	int err;
324
325	if (client->irq <= 0)
326	return -EINVAL;
327
328	err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
329	if (err)
330	return err;
331
332	err = rx8025_read_reg(client, RX8025_REG_CTRL2, &ctrl2);
333	if (err)
334	return err;
335
336	dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
337	__func__, ald[0], ald[1], ctrl2);
338
339	/* Hardware alarms precision is 1 minute! */
340	t->time.tm_sec = 0;
341	t->time.tm_min = bcd2bin(ald[0] & 0x7f);
342	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
343	t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
344	else
345	t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
346	+ (ald[1] & 0x20 ? 12 : 0);
347
348	t->time.tm_wday = -1;
349	t->time.tm_mday = -1;
350	t->time.tm_mon = -1;
351	t->time.tm_year = -1;
352
353	dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
354	__func__,
355	t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
356	t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
357	t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
358	t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
359
360	return err;
361	}
362
363	static int rx8025_set_alarm(struct device dev, struct rtc_wkalrm t)
364	{
365	struct i2c_client *client = to_i2c_client(dev);
366	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
367	u8 ald[2];
368	int err;
369
370	if (client->irq <= 0)
371	return -EINVAL;
372
373	/* Hardware alarm precision is 1 minute! */
374	ald[0] = bin2bcd(t->time.tm_min);
375	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
376	ald[1] = bin2bcd(t->time.tm_hour);
377	else
378	ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
379	\| bin2bcd((t->time.tm_hour + 11) % 12 + 1);
380
381	dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
382
383	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
384	rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
385	err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
386	rx8025->ctrl1);
387	if (err)
388	return err;
389	}
390	err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
391	if (err)
392	return err;
393
394	if (t->enabled) {
395	rx8025->ctrl1 \|= RX8025_BIT_CTRL1_DALE;
396	err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
397	rx8025->ctrl1);
398	if (err)
399	return err;
400	}
401
402	return 0;
403	}
404
405	static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
406	{
407	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
408	u8 ctrl1;
409	int err;
410
411	ctrl1 = rx8025->ctrl1;
412	if (enabled)
413	ctrl1 \|= RX8025_BIT_CTRL1_DALE;
414	else
415	ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
416
417	if (ctrl1 != rx8025->ctrl1) {
418	rx8025->ctrl1 = ctrl1;
419	err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
420	rx8025->ctrl1);
421	if (err)
422	return err;
423	}
424	return 0;
425	}
426
3c2b9075 WG	427	static struct rtc_class_ops rx8025_rtc_ops = {
	428	.read_time = rx8025_get_time,
	429	.set_time = rx8025_set_time,
	430	.read_alarm = rx8025_read_alarm,
	431	.set_alarm = rx8025_set_alarm,
	432	.alarm_irq_enable = rx8025_alarm_irq_enable,
3c2b9075 WG	433	};
	434
	435	/*
	436	* Clock precision adjustment support
	437	*
	438	* According to the RX8025 SA/NB application manual the frequency and
b770ffd4	439	* temperature characteristics can be approximated using the following
3c2b9075 WG	440	* equation:
	441	*
	442	* df = a * (ut - t)**2
	443	*
	444	* df: Frequency deviation in any temperature
	445	* a : Coefficient = (-35 +-5) * 10**-9
	446	* ut: Ultimate temperature in degree = +25 +-5 degree
	447	* t : Any temperature in degree
	448	*
	449	* Note that the clock adjustment in ppb must be entered (which is
	450	* the negative value of the deviation).
	451	*/
	452	static int rx8025_get_clock_adjust(struct device dev, int adj)
	453	{
	454	struct i2c_client *client = to_i2c_client(dev);
	455	u8 digoff;
	456	int err;
	457
	458	err = rx8025_read_reg(client, RX8025_REG_DIGOFF, &digoff);
	459	if (err)
	460	return err;
	461
	462	*adj = digoff >= 64 ? digoff - 128 : digoff;
	463	if (*adj > 0)
	464	(*adj)--;
	465	adj = -RX8025_ADJ_RESOLUTION;
	466
	467	return 0;
	468	}
	469
	470	static int rx8025_set_clock_adjust(struct device *dev, int adj)
	471	{
	472	struct i2c_client *client = to_i2c_client(dev);
	473	u8 digoff;
	474	int err;
	475
	476	adj /= -RX8025_ADJ_RESOLUTION;
	477	if (adj > RX8025_ADJ_DATA_MAX)
	478	adj = RX8025_ADJ_DATA_MAX;
	479	else if (adj < RX8025_ADJ_DATA_MIN)
	480	adj = RX8025_ADJ_DATA_MIN;
	481	else if (adj > 0)
	482	adj++;
	483	else if (adj < 0)
	484	adj += 128;
	485	digoff = adj;
	486
	487	err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
	488	if (err)
	489	return err;
	490
	491	dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
	492
	493	return 0;
	494	}
	495
	496	static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
	497	struct device_attribute *attr,
	498	char *buf)
	499	{
	500	int err, adj;
	501
	502	err = rx8025_get_clock_adjust(dev, &adj);
	503	if (err)
504	return err;
505
506	return sprintf(buf, "%d\n", adj);
507	}
508
509	static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
510	struct device_attribute *attr,
511	const char *buf, size_t count)
512	{
513	int adj, err;
514
515	if (sscanf(buf, "%i", &adj) != 1)
516	return -EINVAL;
517
518	err = rx8025_set_clock_adjust(dev, adj);
519
520	return err ? err : count;
521	}
522
523	static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO \| S_IWUSR,
524	rx8025_sysfs_show_clock_adjust,
525	rx8025_sysfs_store_clock_adjust);
526
527	static int rx8025_sysfs_register(struct device *dev)
528	{
529	return device_create_file(dev, &dev_attr_clock_adjust_ppb);
530	}
531
532	static void rx8025_sysfs_unregister(struct device *dev)
533	{
534	device_remove_file(dev, &dev_attr_clock_adjust_ppb);
535	}
536
537	static int __devinit rx8025_probe(struct i2c_client *client,
538	const struct i2c_device_id *id)
539	{
540	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
541	struct rx8025_data *rx8025;
542	int err, need_reset = 0;
543
544	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
545	\| I2C_FUNC_SMBUS_I2C_BLOCK)) {
546	dev_err(&adapter->dev,
547	"doesn't support required functionality\n");
548	err = -EIO;
549	goto errout;
550	}
551
552	rx8025 = kzalloc(sizeof(*rx8025), GFP_KERNEL);
553	if (!rx8025) {
554	dev_err(&adapter->dev, "failed to alloc memory\n");
555	err = -ENOMEM;
556	goto errout;
557	}
558
559	rx8025->client = client;
560	i2c_set_clientdata(client, rx8025);
561	INIT_WORK(&rx8025->work, rx8025_work);
562
563	err = rx8025_init_client(client, &need_reset);
564	if (err)
565	goto errout_free;
566
567	if (need_reset) {
568	struct rtc_time tm;
569	dev_info(&client->dev,
570	"bad conditions detected, resetting date\n");
571	rtc_time_to_tm(0, &tm); /* 1970/1/1 */
572	rx8025_set_time(&client->dev, &tm);
573	}
574
575	rx8025->rtc = rtc_device_register(client->name, &client->dev,
576	&rx8025_rtc_ops, THIS_MODULE);
577	if (IS_ERR(rx8025->rtc)) {
578	err = PTR_ERR(rx8025->rtc);
579	dev_err(&client->dev, "unable to register the class device\n");
580	goto errout_free;
581	}
582
583	if (client->irq > 0) {
584	dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
585	err = request_irq(client->irq, rx8025_irq,
586	0, "rx8025", client);
587	if (err) {
588	dev_err(&client->dev, "unable to request IRQ\n");
589	goto errout_reg;
590	}
591	}
592
593	rx8025->rtc->irq_freq = 1;
594	rx8025->rtc->max_user_freq = 1;
595
596	err = rx8025_sysfs_register(&client->dev);
597	if (err)
598	goto errout_irq;
599
600	return 0;
601
602	errout_irq:
603	if (client->irq > 0)
604	free_irq(client->irq, client);
605
606	errout_reg:
607	rtc_device_unregister(rx8025->rtc);
608
609	errout_free:
3c2b9075 WG	610	kfree(rx8025);
	611
	612	errout:
	613	dev_err(&adapter->dev, "probing for rx8025 failed\n");
	614	return err;
	615	}
	616
	617	static int __devexit rx8025_remove(struct i2c_client *client)
	618	{
	619	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
	620	struct mutex *lock = &rx8025->rtc->ops_lock;
	621
	622	if (client->irq > 0) {
	623	mutex_lock(lock);
	624	rx8025->exiting = 1;
	625	mutex_unlock(lock);
	626
	627	free_irq(client->irq, client);
9db8995b	628	cancel_work_sync(&rx8025->work);
3c2b9075 WG	629	}
	630
	631	rx8025_sysfs_unregister(&client->dev);
	632	rtc_device_unregister(rx8025->rtc);
3c2b9075 WG	633	kfree(rx8025);
	634	return 0;
	635	}
	636
	637	static struct i2c_driver rx8025_driver = {
	638	.driver = {
	639	.name = "rtc-rx8025",
	640	.owner = THIS_MODULE,
	641	},
	642	.probe = rx8025_probe,
	643	.remove = __devexit_p(rx8025_remove),
	644	.id_table = rx8025_id,
	645	};
	646
0abc9201	647	module_i2c_driver(rx8025_driver);
3c2b9075 WG	648
	649	MODULE_AUTHOR("Wolfgang Grandegger <[email protected]>");
	650	MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
	651	MODULE_LICENSE("GPL");