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

/*
 * 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
 * <lm-sensors@lm-sensors.org>
 * 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/bcd.h>
#include <linux/bitops.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.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	BIT(3)
#define RX8025_BIT_CTRL1_1224	BIT(5)
#define RX8025_BIT_CTRL1_DALE	BIT(6)
#define RX8025_BIT_CTRL1_WALE	BIT(7)

#define RX8025_BIT_CTRL2_DAFG	BIT(0)
#define RX8025_BIT_CTRL2_WAFG	BIT(1)
#define RX8025_BIT_CTRL2_CTFG	BIT(2)
#define RX8025_BIT_CTRL2_PON	BIT(4)
#define RX8025_BIT_CTRL2_XST	BIT(5)
#define RX8025_BIT_CTRL2_VDET	BIT(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;
	u8 ctrl1;
};

static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
{
	return i2c_smbus_read_byte_data(client, number << 4);
}

static int rx8025_read_regs(const struct i2c_client *client,
			    u8 number, u8 length, u8 *values)
{
	int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length,
						values);
	if (ret != length)
		return ret < 0 ? ret : -EIO;

	return 0;
}

static s32 rx8025_write_reg(const struct i2c_client *client, u8 number,
			    u8 value)
{
	return i2c_smbus_write_byte_data(client, number << 4, value);
}

static s32 rx8025_write_regs(const struct i2c_client *client,
			     u8 number, u8 length, const u8 *values)
{
	return i2c_smbus_write_i2c_block_data(client, number << 4,
					      length, values);
}

static int rx8025_check_validity(struct device *dev)
{
	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	int ctrl2;

	ctrl2 = rx8025_read_reg(rx8025->client, RX8025_REG_CTRL2);
	if (ctrl2 < 0)
		return ctrl2;

	if (ctrl2 & RX8025_BIT_CTRL2_VDET)
		dev_warn(dev, "power voltage drop detected\n");

	if (ctrl2 & RX8025_BIT_CTRL2_PON) {
		dev_warn(dev, "power-on reset detected, date is invalid\n");
		return -EINVAL;
	}

	if (!(ctrl2 & RX8025_BIT_CTRL2_XST)) {
		dev_warn(dev, "crystal stopped, date is invalid\n");
		return -EINVAL;
	}

	return 0;
}

static int rx8025_reset_validity(struct i2c_client *client)
{
	int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);

	if (ctrl2 < 0)
		return ctrl2;

	ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET);

	return rx8025_write_reg(client, RX8025_REG_CTRL2,
				ctrl2 | RX8025_BIT_CTRL2_XST);
}

static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
{
	struct i2c_client *client = dev_id;
	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
	struct mutex *lock = &rx8025->rtc->ops_lock;
	int status;

	mutex_lock(lock);
	status = rx8025_read_reg(client, RX8025_REG_CTRL2);
	if (status < 0)
		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;
		rtc_update_irq(rx8025->rtc, 1, RTC_PF | RTC_IRQF);
	}

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

out:
	mutex_unlock(lock);

	return IRQ_HANDLED;
}

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_check_validity(dev);
	if (err)
		return 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]) + 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];
	int ret;

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

	/*
	 * 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]);

	ret = rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
	if (ret < 0)
		return ret;

	return rx8025_reset_validity(rx8025->client);
}

static int rx8025_init_client(struct i2c_client *client)
{
	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_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_clear) {
		ctrl2 = ctrl[1];
		ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
			   RX8025_BIT_CTRL2_DAFG);

		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 ald[2];
	int ctrl2, err;

	if (client->irq <= 0)
		return -EINVAL;

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

	ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
	if (ctrl2 < 0)
		return ctrl2;

	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);

	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!
	 * round up to nearest minute
	 */
	if (t->time.tm_sec) {
		time64_t alarm_time = rtc_tm_to_time64(&t->time);

		alarm_time += 60 - t->time.tm_sec;
		rtc_time64_to_tm(alarm_time, &t->time);
	}

	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 const 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);
	int digoff;

	digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
	if (digoff < 0)
		return digoff;

	*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 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 = 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");
		return -EIO;
	}

	rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
	if (!rx8025)
		return -ENOMEM;

	rx8025->client = client;
	i2c_set_clientdata(client, rx8025);

	err = rx8025_init_client(client);
	if (err)
		return err;

	rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
					  &rx8025_rtc_ops, THIS_MODULE);
	if (IS_ERR(rx8025->rtc)) {
		dev_err(&client->dev, "unable to register the class device\n");
		return PTR_ERR(rx8025->rtc);
	}

	if (client->irq > 0) {
		dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
		err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
						rx8025_handle_irq,
						IRQF_ONESHOT,
						"rx8025", client);
		if (err) {
			dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
			client->irq = 0;
		}
	}

	rx8025->rtc->max_user_freq = 1;

	/* the rx8025 alarm only supports a minute accuracy */
	rx8025->rtc->uie_unsupported = 1;

	err = rx8025_sysfs_register(&client->dev);
	return err;
}

static int rx8025_remove(struct i2c_client *client)
{
	rx8025_sysfs_unregister(&client->dev);
	return 0;
}

static struct i2c_driver rx8025_driver = {
	.driver = {
		.name = "rtc-rx8025",
	},
	.probe		= rx8025_probe,
	.remove		= rx8025_remove,
	.id_table	= rx8025_id,
};

module_i2c_driver(rx8025_driver);

MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
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 <wg@grandegger.com>
	5	*
	6	* Copyright (C) 2005 by Digi International Inc.
	7	* All rights reserved.
	8	*
	9	* Modified by fengjh at rising.com.cn
d00cd819	10	* <lm-sensors@lm-sensors.org>
3c2b9075 WG	11	* 2006.11
	12	*
	13	* Code cleanup by Sergei Poselenov, <sposelenov@emcraft.com>
	14	* Converted to new style by Wolfgang Grandegger <wg@grandegger.com>
	15	* Alarm and periodic interrupt added by Dmitry Rakhchev <rda@emcraft.com>
	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	*/
3c2b9075	21	#include <linux/bcd.h>
2ddd1869	22	#include <linux/bitops.h>
3c2b9075	23	#include <linux/i2c.h>
15d3bdc2 AB	24	#include <linux/kernel.h>
15d3bdc2 AB	25	#include <linux/module.h>
3c2b9075 WG	26	#include <linux/rtc.h>
	27
	28	/* Register definitions */
	29	#define RX8025_REG_SEC 0x00
	30	#define RX8025_REG_MIN 0x01
	31	#define RX8025_REG_HOUR 0x02
	32	#define RX8025_REG_WDAY 0x03
	33	#define RX8025_REG_MDAY 0x04
	34	#define RX8025_REG_MONTH 0x05
	35	#define RX8025_REG_YEAR 0x06
	36	#define RX8025_REG_DIGOFF 0x07
	37	#define RX8025_REG_ALWMIN 0x08
	38	#define RX8025_REG_ALWHOUR 0x09
	39	#define RX8025_REG_ALWWDAY 0x0a
	40	#define RX8025_REG_ALDMIN 0x0b
	41	#define RX8025_REG_ALDHOUR 0x0c
	42	/* 0x0d is reserved */
	43	#define RX8025_REG_CTRL1 0x0e
	44	#define RX8025_REG_CTRL2 0x0f
	45
	46	#define RX8025_BIT_CTRL1_CT (7 << 0)
	47	/* 1 Hz periodic level irq */
	48	#define RX8025_BIT_CTRL1_CT_1HZ 4
2ddd1869 AB	49	#define RX8025_BIT_CTRL1_TEST BIT(3)
	50	#define RX8025_BIT_CTRL1_1224 BIT(5)
	51	#define RX8025_BIT_CTRL1_DALE BIT(6)
	52	#define RX8025_BIT_CTRL1_WALE BIT(7)
3c2b9075	53
2ddd1869 AB	54	#define RX8025_BIT_CTRL2_DAFG BIT(0)
	55	#define RX8025_BIT_CTRL2_WAFG BIT(1)
	56	#define RX8025_BIT_CTRL2_CTFG BIT(2)
	57	#define RX8025_BIT_CTRL2_PON BIT(4)
	58	#define RX8025_BIT_CTRL2_XST BIT(5)
	59	#define RX8025_BIT_CTRL2_VDET BIT(6)
3c2b9075 WG	60
	61	/* Clock precision adjustment */
	62	#define RX8025_ADJ_RESOLUTION 3050 /* in ppb */
	63	#define RX8025_ADJ_DATA_MAX 62
	64	#define RX8025_ADJ_DATA_MIN -62
	65
	66	static const struct i2c_device_id rx8025_id[] = {
	67	{ "rx8025", 0 },
	68	{ }
	69	};
	70	MODULE_DEVICE_TABLE(i2c, rx8025_id);
	71
	72	struct rx8025_data {
	73	struct i2c_client *client;
	74	struct rtc_device *rtc;
3c2b9075	75	u8 ctrl1;
3c2b9075 WG	76	};
3c2b9075 WG	77
fd9061fb	78	static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
3c2b9075	79	{
fd9061fb	80	return i2c_smbus_read_byte_data(client, number << 4);
3c2b9075 WG	81	}
3c2b9075 WG	82
fd9061fb AB	83	static int rx8025_read_regs(const struct i2c_client *client,
fd9061fb AB	84	u8 number, u8 length, u8 *values)
3c2b9075	85	{
fd9061fb AB	86	int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length,
	87	values);
	88	if (ret != length)
3c2b9075	89	return ret < 0 ? ret : -EIO;
3c2b9075 WG	90
	91	return 0;
	92	}
	93
fd9061fb AB	94	static s32 rx8025_write_reg(const struct i2c_client *client, u8 number,
fd9061fb AB	95	u8 value)
3c2b9075	96	{
fd9061fb	97	return i2c_smbus_write_byte_data(client, number << 4, value);
3c2b9075 WG	98	}
3c2b9075 WG	99
fd9061fb AB	100	static s32 rx8025_write_regs(const struct i2c_client *client,
fd9061fb AB	101	u8 number, u8 length, const u8 *values)
3c2b9075	102	{
fd9061fb AB	103	return i2c_smbus_write_i2c_block_data(client, number << 4,
fd9061fb AB	104	length, values);
3c2b9075 WG	105	}
3c2b9075 WG	106
efbbb4fd AB	107	static int rx8025_check_validity(struct device *dev)
	108	{
	109	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	110	int ctrl2;
	111
	112	ctrl2 = rx8025_read_reg(rx8025->client, RX8025_REG_CTRL2);
	113	if (ctrl2 < 0)
	114	return ctrl2;
	115
	116	if (ctrl2 & RX8025_BIT_CTRL2_VDET)
	117	dev_warn(dev, "power voltage drop detected\n");
	118
	119	if (ctrl2 & RX8025_BIT_CTRL2_PON) {
	120	dev_warn(dev, "power-on reset detected, date is invalid\n");
	121	return -EINVAL;
	122	}
	123
	124	if (!(ctrl2 & RX8025_BIT_CTRL2_XST)) {
	125	dev_warn(dev, "crystal stopped, date is invalid\n");
	126	return -EINVAL;
	127	}
	128
	129	return 0;
	130	}
	131
8c4a4467 AB	132	static int rx8025_reset_validity(struct i2c_client *client)
	133	{
	134	int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
	135
	136	if (ctrl2 < 0)
	137	return ctrl2;
	138
	139	ctrl2 &= ~(RX8025_BIT_CTRL2_PON \| RX8025_BIT_CTRL2_VDET);
	140
	141	return rx8025_write_reg(client, RX8025_REG_CTRL2,
	142	ctrl2 \| RX8025_BIT_CTRL2_XST);
	143	}
	144
b6a57c95	145	static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
3c2b9075 WG	146	{
	147	struct i2c_client *client = dev_id;
	148	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
9dbe3852	149	struct mutex *lock = &rx8025->rtc->ops_lock;
fd9061fb	150	int status;
3c2b9075	151
9dbe3852	152	mutex_lock(lock);
fd9061fb AB	153	status = rx8025_read_reg(client, RX8025_REG_CTRL2);
fd9061fb AB	154	if (status < 0)
3c2b9075 WG	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;
3c2b9075	164	rtc_update_irq(rx8025->rtc, 1, RTC_PF \| RTC_IRQF);
3c2b9075 WG	165	}
	166
	167	if (status & RX8025_BIT_CTRL2_DAFG) {
	168	/* alarm */
	169	status &= RX8025_BIT_CTRL2_DAFG;
	170	if (rx8025_write_reg(client, RX8025_REG_CTRL1,
	171	rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
	172	goto out;
3c2b9075	173	rtc_update_irq(rx8025->rtc, 1, RTC_AF \| RTC_IRQF);
3c2b9075 WG	174	}
3c2b9075 WG	175
3c2b9075	176	out:
9dbe3852 AM	177	mutex_unlock(lock);
9dbe3852 AM	178
b6a57c95	179	return IRQ_HANDLED;
3c2b9075 WG	180	}
	181
	182	static int rx8025_get_time(struct device dev, struct rtc_time dt)
	183	{
	184	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
fd9061fb	185	u8 date[7];
efbbb4fd	186	int err;
6f0a8cfe	187
efbbb4fd AB	188	err = rx8025_check_validity(dev);
	189	if (err)
	190	return err;
6f0a8cfe	191
3c2b9075 WG	192	err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
	193	if (err)
	194	return err;
	195
	196	dev_dbg(dev, "%s: read 0x%02x 0x%02x "
	197	"0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
	198	date[0], date[1], date[2], date[3], date[4],
	199	date[5], date[6]);
	200
	201	dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
	202	dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
	203	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	204	dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
	205	else
	206	dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
	207	+ (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
	208
	209	dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
	210	dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
32672c55	211	dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
3c2b9075 WG	212
	213	dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
	214	dt->tm_sec, dt->tm_min, dt->tm_hour,
	215	dt->tm_mday, dt->tm_mon, dt->tm_year);
	216
	217	return rtc_valid_tm(dt);
	218	}
	219
	220	static int rx8025_set_time(struct device dev, struct rtc_time dt)
	221	{
	222	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	223	u8 date[7];
8c4a4467	224	int ret;
3c2b9075	225
32672c55 AB	226	if ((dt->tm_year < 100) \|\| (dt->tm_year > 199))
32672c55 AB	227	return -EINVAL;
3c2b9075 WG	228
	229	/*
	230	* Here the read-only bits are written as "0". I'm not sure if that
	231	* is sound.
	232	*/
	233	date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
	234	date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
	235	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	236	date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
	237	else
	238	date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
	239	\| bin2bcd((dt->tm_hour + 11) % 12 + 1);
	240
	241	date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
	242	date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
	243	date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
32672c55	244	date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
3c2b9075 WG	245
	246	dev_dbg(dev,
	247	"%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
	248	__func__,
	249	date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
	250
8c4a4467 AB	251	ret = rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
	252	if (ret < 0)
	253	return ret;
	254
	255	return rx8025_reset_validity(rx8025->client);
3c2b9075 WG	256	}
3c2b9075 WG	257
6f0a8cfe	258	static int rx8025_init_client(struct i2c_client *client)
3c2b9075 WG	259	{
	260	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
	261	u8 ctrl[2], ctrl2;
	262	int need_clear = 0;
	263	int err;
	264
	265	err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
	266	if (err)
	267	goto out;
	268
	269	/* Keep test bit zero ! */
	270	rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
	271
3c2b9075 WG	272	if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG \| RX8025_BIT_CTRL2_WAFG)) {
	273	dev_warn(&client->dev, "Alarm was detected\n");
	274	need_clear = 1;
	275	}
	276
5c66e1e0	277	if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
3c2b9075 WG	278	need_clear = 1;
3c2b9075 WG	279
6f0a8cfe	280	if (need_clear) {
a27c7bf6	281	ctrl2 = ctrl[1];
8c4a4467	282	ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG \| RX8025_BIT_CTRL2_WAFG \|
3c2b9075	283	RX8025_BIT_CTRL2_DAFG);
3c2b9075 WG	284
	285	err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
	286	}
	287	out:
	288	return err;
	289	}
	290
	291	/* Alarm support */
	292	static int rx8025_read_alarm(struct device dev, struct rtc_wkalrm t)
	293	{
	294	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	295	struct i2c_client *client = rx8025->client;
fd9061fb AB	296	u8 ald[2];
fd9061fb AB	297	int ctrl2, err;
3c2b9075 WG	298
	299	if (client->irq <= 0)
	300	return -EINVAL;
	301
	302	err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
	303	if (err)
	304	return err;
	305
fd9061fb AB	306	ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
	307	if (ctrl2 < 0)
	308	return ctrl2;
3c2b9075 WG	309
	310	dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
	311	__func__, ald[0], ald[1], ctrl2);
	312
	313	/* Hardware alarms precision is 1 minute! */
	314	t->time.tm_sec = 0;
	315	t->time.tm_min = bcd2bin(ald[0] & 0x7f);
	316	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	317	t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
	318	else
	319	t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
	320	+ (ald[1] & 0x20 ? 12 : 0);
	321
3c2b9075 WG	322	dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
	323	__func__,
	324	t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
	325	t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
	326	t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
	327	t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
	328
	329	return err;
	330	}
	331
	332	static int rx8025_set_alarm(struct device dev, struct rtc_wkalrm t)
	333	{
	334	struct i2c_client *client = to_i2c_client(dev);
	335	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	336	u8 ald[2];
	337	int err;
	338
	339	if (client->irq <= 0)
	340	return -EINVAL;
	341
302c5608 AM	342	/*
	343	* Hardware alarm precision is 1 minute!
	344	* round up to nearest minute
	345	*/
	346	if (t->time.tm_sec) {
	347	time64_t alarm_time = rtc_tm_to_time64(&t->time);
	348
	349	alarm_time += 60 - t->time.tm_sec;
	350	rtc_time64_to_tm(alarm_time, &t->time);
	351	}
	352
3c2b9075 WG	353	ald[0] = bin2bcd(t->time.tm_min);
	354	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	355	ald[1] = bin2bcd(t->time.tm_hour);
	356	else
	357	ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
	358	\| bin2bcd((t->time.tm_hour + 11) % 12 + 1);
	359
	360	dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
	361
	362	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
	363	rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
	364	err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
	365	rx8025->ctrl1);
	366	if (err)
	367	return err;
	368	}
	369	err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
	370	if (err)
	371	return err;
	372
	373	if (t->enabled) {
	374	rx8025->ctrl1 \|= RX8025_BIT_CTRL1_DALE;
	375	err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
	376	rx8025->ctrl1);
	377	if (err)
	378	return err;
	379	}
	380
	381	return 0;
	382	}
	383
	384	static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
	385	{
	386	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	387	u8 ctrl1;
	388	int err;
	389
	390	ctrl1 = rx8025->ctrl1;
	391	if (enabled)
	392	ctrl1 \|= RX8025_BIT_CTRL1_DALE;
	393	else
	394	ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
	395
	396	if (ctrl1 != rx8025->ctrl1) {
	397	rx8025->ctrl1 = ctrl1;
	398	err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
	399	rx8025->ctrl1);
	400	if (err)
	401	return err;
	402	}
	403	return 0;
	404	}
	405
34c7b3ac	406	static const struct rtc_class_ops rx8025_rtc_ops = {
3c2b9075 WG	407	.read_time = rx8025_get_time,
	408	.set_time = rx8025_set_time,
	409	.read_alarm = rx8025_read_alarm,
	410	.set_alarm = rx8025_set_alarm,
	411	.alarm_irq_enable = rx8025_alarm_irq_enable,
3c2b9075 WG	412	};
	413
	414	/*
	415	* Clock precision adjustment support
	416	*
	417	* According to the RX8025 SA/NB application manual the frequency and
b770ffd4	418	* temperature characteristics can be approximated using the following
3c2b9075 WG	419	* equation:
	420	*
	421	* df = a * (ut - t)**2
	422	*
	423	* df: Frequency deviation in any temperature
	424	* a : Coefficient = (-35 +-5) * 10**-9
	425	* ut: Ultimate temperature in degree = +25 +-5 degree
	426	* t : Any temperature in degree
	427	*
	428	* Note that the clock adjustment in ppb must be entered (which is
	429	* the negative value of the deviation).
	430	*/
	431	static int rx8025_get_clock_adjust(struct device dev, int adj)
	432	{
	433	struct i2c_client *client = to_i2c_client(dev);
fd9061fb	434	int digoff;
3c2b9075	435
fd9061fb AB	436	digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
	437	if (digoff < 0)
	438	return digoff;
3c2b9075 WG	439
	440	*adj = digoff >= 64 ? digoff - 128 : digoff;
	441	if (*adj > 0)
	442	(*adj)--;
	443	adj = -RX8025_ADJ_RESOLUTION;
	444
	445	return 0;
	446	}
	447
	448	static int rx8025_set_clock_adjust(struct device *dev, int adj)
	449	{
	450	struct i2c_client *client = to_i2c_client(dev);
	451	u8 digoff;
	452	int err;
	453
	454	adj /= -RX8025_ADJ_RESOLUTION;
	455	if (adj > RX8025_ADJ_DATA_MAX)
	456	adj = RX8025_ADJ_DATA_MAX;
	457	else if (adj < RX8025_ADJ_DATA_MIN)
	458	adj = RX8025_ADJ_DATA_MIN;
	459	else if (adj > 0)
	460	adj++;
	461	else if (adj < 0)
	462	adj += 128;
	463	digoff = adj;
	464
	465	err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
	466	if (err)
	467	return err;
	468
	469	dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
	470
	471	return 0;
	472	}
	473
	474	static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
	475	struct device_attribute *attr,
	476	char *buf)
	477	{
	478	int err, adj;
	479
	480	err = rx8025_get_clock_adjust(dev, &adj);
	481	if (err)
	482	return err;
	483
	484	return sprintf(buf, "%d\n", adj);
	485	}
	486
	487	static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
	488	struct device_attribute *attr,
	489	const char *buf, size_t count)
	490	{
	491	int adj, err;
	492
	493	if (sscanf(buf, "%i", &adj) != 1)
	494	return -EINVAL;
	495
	496	err = rx8025_set_clock_adjust(dev, adj);
	497
	498	return err ? err : count;
	499	}
	500
	501	static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO \| S_IWUSR,
	502	rx8025_sysfs_show_clock_adjust,
503	rx8025_sysfs_store_clock_adjust);
504
505	static int rx8025_sysfs_register(struct device *dev)
506	{
507	return device_create_file(dev, &dev_attr_clock_adjust_ppb);
508	}
509
510	static void rx8025_sysfs_unregister(struct device *dev)
511	{
512	device_remove_file(dev, &dev_attr_clock_adjust_ppb);
513	}
514
5a167f45 GKH	515	static int rx8025_probe(struct i2c_client *client,
5a167f45 GKH	516	const struct i2c_device_id *id)
3c2b9075 WG	517	{
	518	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
	519	struct rx8025_data *rx8025;
6f0a8cfe	520	int err = 0;
3c2b9075 WG	521
	522	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
	523	\| I2C_FUNC_SMBUS_I2C_BLOCK)) {
	524	dev_err(&adapter->dev,
	525	"doesn't support required functionality\n");
dbcce7cf	526	return -EIO;
3c2b9075 WG	527	}
3c2b9075 WG	528
fac42b41	529	rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
b1f9d790	530	if (!rx8025)
dbcce7cf	531	return -ENOMEM;
3c2b9075 WG	532
	533	rx8025->client = client;
	534	i2c_set_clientdata(client, rx8025);
3c2b9075	535
6f0a8cfe	536	err = rx8025_init_client(client);
3c2b9075	537	if (err)
dbcce7cf	538	return err;
3c2b9075	539
fac42b41	540	rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
3c2b9075 WG	541	&rx8025_rtc_ops, THIS_MODULE);
3c2b9075 WG	542	if (IS_ERR(rx8025->rtc)) {
3c2b9075	543	dev_err(&client->dev, "unable to register the class device\n");
dbcce7cf	544	return PTR_ERR(rx8025->rtc);
3c2b9075 WG	545	}
	546
	547	if (client->irq > 0) {
	548	dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
f0b63a1d	549	err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
0a966c07 AM	550	rx8025_handle_irq,
	551	IRQF_ONESHOT,
	552	"rx8025", client);
3c2b9075	553	if (err) {
8a06513d AB	554	dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
8a06513d AB	555	client->irq = 0;
3c2b9075 WG	556	}
	557	}
	558
3c2b9075 WG	559	rx8025->rtc->max_user_freq = 1;
3c2b9075 WG	560
ef5f4a9e AM	561	/* the rx8025 alarm only supports a minute accuracy */
	562	rx8025->rtc->uie_unsupported = 1;
	563
3c2b9075	564	err = rx8025_sysfs_register(&client->dev);
3c2b9075 WG	565	return err;
	566	}
	567
5a167f45	568	static int rx8025_remove(struct i2c_client *client)
3c2b9075	569	{
3c2b9075	570	rx8025_sysfs_unregister(&client->dev);
3c2b9075 WG	571	return 0;
	572	}
	573
	574	static struct i2c_driver rx8025_driver = {
	575	.driver = {
	576	.name = "rtc-rx8025",
3c2b9075 WG	577	},
3c2b9075 WG	578	.probe = rx8025_probe,
5a167f45	579	.remove = rx8025_remove,
3c2b9075 WG	580	.id_table = rx8025_id,
	581	};
	582
0abc9201	583	module_i2c_driver(rx8025_driver);
3c2b9075 WG	584
	585	MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
	586	MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
	587	MODULE_LICENSE("GPL");