[linux-2.6-block.git] / drivers / rtc / rtc-rx8025.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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>
 */
#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 %7ph\n", __func__, date);

	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 %ptRr\n", __func__, dt);

	return 0;
}

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 %7ph\n", __func__, date);

	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: %ptRr\n", __func__, &t->time);
	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 = client->adapter;
	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
d2912cb1	1	// SPDX-License-Identifier: GPL-2.0-only
3c2b9075 WG	2	/*
	3	* Driver for Epson's RTC module RX-8025 SA/NB
	4	*
	5	* Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com>
	6	*
	7	* Copyright (C) 2005 by Digi International Inc.
	8	* All rights reserved.
	9	*
	10	* Modified by fengjh at rising.com.cn
d00cd819	11	* <lm-sensors@lm-sensors.org>
3c2b9075 WG	12	* 2006.11
	13	*
	14	* Code cleanup by Sergei Poselenov, <sposelenov@emcraft.com>
	15	* Converted to new style by Wolfgang Grandegger <wg@grandegger.com>
	16	* Alarm and periodic interrupt added by Dmitry Rakhchev <rda@emcraft.com>
3c2b9075	17	*/
3c2b9075	18	#include <linux/bcd.h>
2ddd1869	19	#include <linux/bitops.h>
3c2b9075	20	#include <linux/i2c.h>
15d3bdc2 AB	21	#include <linux/kernel.h>
15d3bdc2 AB	22	#include <linux/module.h>
3c2b9075 WG	23	#include <linux/rtc.h>
	24
	25	/* Register definitions */
	26	#define RX8025_REG_SEC 0x00
	27	#define RX8025_REG_MIN 0x01
	28	#define RX8025_REG_HOUR 0x02
	29	#define RX8025_REG_WDAY 0x03
	30	#define RX8025_REG_MDAY 0x04
	31	#define RX8025_REG_MONTH 0x05
	32	#define RX8025_REG_YEAR 0x06
	33	#define RX8025_REG_DIGOFF 0x07
	34	#define RX8025_REG_ALWMIN 0x08
	35	#define RX8025_REG_ALWHOUR 0x09
	36	#define RX8025_REG_ALWWDAY 0x0a
	37	#define RX8025_REG_ALDMIN 0x0b
	38	#define RX8025_REG_ALDHOUR 0x0c
	39	/* 0x0d is reserved */
	40	#define RX8025_REG_CTRL1 0x0e
	41	#define RX8025_REG_CTRL2 0x0f
	42
	43	#define RX8025_BIT_CTRL1_CT (7 << 0)
	44	/* 1 Hz periodic level irq */
	45	#define RX8025_BIT_CTRL1_CT_1HZ 4
2ddd1869 AB	46	#define RX8025_BIT_CTRL1_TEST BIT(3)
	47	#define RX8025_BIT_CTRL1_1224 BIT(5)
	48	#define RX8025_BIT_CTRL1_DALE BIT(6)
	49	#define RX8025_BIT_CTRL1_WALE BIT(7)
3c2b9075	50
2ddd1869 AB	51	#define RX8025_BIT_CTRL2_DAFG BIT(0)
	52	#define RX8025_BIT_CTRL2_WAFG BIT(1)
	53	#define RX8025_BIT_CTRL2_CTFG BIT(2)
	54	#define RX8025_BIT_CTRL2_PON BIT(4)
	55	#define RX8025_BIT_CTRL2_XST BIT(5)
	56	#define RX8025_BIT_CTRL2_VDET BIT(6)
3c2b9075 WG	57
	58	/* Clock precision adjustment */
	59	#define RX8025_ADJ_RESOLUTION 3050 /* in ppb */
	60	#define RX8025_ADJ_DATA_MAX 62
	61	#define RX8025_ADJ_DATA_MIN -62
	62
	63	static const struct i2c_device_id rx8025_id[] = {
	64	{ "rx8025", 0 },
	65	{ }
	66	};
	67	MODULE_DEVICE_TABLE(i2c, rx8025_id);
	68
	69	struct rx8025_data {
	70	struct i2c_client *client;
	71	struct rtc_device *rtc;
3c2b9075	72	u8 ctrl1;
3c2b9075 WG	73	};
3c2b9075 WG	74
fd9061fb	75	static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
3c2b9075	76	{
fd9061fb	77	return i2c_smbus_read_byte_data(client, number << 4);
3c2b9075 WG	78	}
3c2b9075 WG	79
fd9061fb AB	80	static int rx8025_read_regs(const struct i2c_client *client,
fd9061fb AB	81	u8 number, u8 length, u8 *values)
3c2b9075	82	{
fd9061fb AB	83	int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length,
	84	values);
	85	if (ret != length)
3c2b9075	86	return ret < 0 ? ret : -EIO;
3c2b9075 WG	87
	88	return 0;
	89	}
	90
fd9061fb AB	91	static s32 rx8025_write_reg(const struct i2c_client *client, u8 number,
fd9061fb AB	92	u8 value)
3c2b9075	93	{
fd9061fb	94	return i2c_smbus_write_byte_data(client, number << 4, value);
3c2b9075 WG	95	}
3c2b9075 WG	96
fd9061fb AB	97	static s32 rx8025_write_regs(const struct i2c_client *client,
fd9061fb AB	98	u8 number, u8 length, const u8 *values)
3c2b9075	99	{
fd9061fb AB	100	return i2c_smbus_write_i2c_block_data(client, number << 4,
fd9061fb AB	101	length, values);
3c2b9075 WG	102	}
3c2b9075 WG	103
efbbb4fd AB	104	static int rx8025_check_validity(struct device *dev)
	105	{
	106	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	107	int ctrl2;
	108
	109	ctrl2 = rx8025_read_reg(rx8025->client, RX8025_REG_CTRL2);
	110	if (ctrl2 < 0)
	111	return ctrl2;
	112
	113	if (ctrl2 & RX8025_BIT_CTRL2_VDET)
	114	dev_warn(dev, "power voltage drop detected\n");
	115
	116	if (ctrl2 & RX8025_BIT_CTRL2_PON) {
	117	dev_warn(dev, "power-on reset detected, date is invalid\n");
	118	return -EINVAL;
	119	}
	120
	121	if (!(ctrl2 & RX8025_BIT_CTRL2_XST)) {
	122	dev_warn(dev, "crystal stopped, date is invalid\n");
	123	return -EINVAL;
	124	}
	125
	126	return 0;
	127	}
	128
8c4a4467 AB	129	static int rx8025_reset_validity(struct i2c_client *client)
	130	{
	131	int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
	132
	133	if (ctrl2 < 0)
	134	return ctrl2;
	135
	136	ctrl2 &= ~(RX8025_BIT_CTRL2_PON \| RX8025_BIT_CTRL2_VDET);
	137
	138	return rx8025_write_reg(client, RX8025_REG_CTRL2,
	139	ctrl2 \| RX8025_BIT_CTRL2_XST);
	140	}
	141
b6a57c95	142	static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
3c2b9075 WG	143	{
	144	struct i2c_client *client = dev_id;
	145	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
9dbe3852	146	struct mutex *lock = &rx8025->rtc->ops_lock;
fd9061fb	147	int status;
3c2b9075	148
9dbe3852	149	mutex_lock(lock);
fd9061fb AB	150	status = rx8025_read_reg(client, RX8025_REG_CTRL2);
fd9061fb AB	151	if (status < 0)
3c2b9075 WG	152	goto out;
	153
	154	if (!(status & RX8025_BIT_CTRL2_XST))
	155	dev_warn(&client->dev, "Oscillation stop was detected,"
	156	"you may have to readjust the clock\n");
	157
	158	if (status & RX8025_BIT_CTRL2_CTFG) {
	159	/* periodic */
	160	status &= ~RX8025_BIT_CTRL2_CTFG;
3c2b9075	161	rtc_update_irq(rx8025->rtc, 1, RTC_PF \| RTC_IRQF);
3c2b9075 WG	162	}
	163
	164	if (status & RX8025_BIT_CTRL2_DAFG) {
	165	/* alarm */
	166	status &= RX8025_BIT_CTRL2_DAFG;
	167	if (rx8025_write_reg(client, RX8025_REG_CTRL1,
	168	rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
	169	goto out;
3c2b9075	170	rtc_update_irq(rx8025->rtc, 1, RTC_AF \| RTC_IRQF);
3c2b9075 WG	171	}
3c2b9075 WG	172
3c2b9075	173	out:
9dbe3852 AM	174	mutex_unlock(lock);
9dbe3852 AM	175
b6a57c95	176	return IRQ_HANDLED;
3c2b9075 WG	177	}
	178
	179	static int rx8025_get_time(struct device dev, struct rtc_time dt)
	180	{
	181	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
fd9061fb	182	u8 date[7];
efbbb4fd	183	int err;
6f0a8cfe	184
efbbb4fd AB	185	err = rx8025_check_validity(dev);
	186	if (err)
	187	return err;
6f0a8cfe	188
3c2b9075 WG	189	err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
	190	if (err)
	191	return err;
	192
1921cab1	193	dev_dbg(dev, "%s: read %7ph\n", __func__, date);
3c2b9075 WG	194
	195	dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
	196	dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
	197	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	198	dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
	199	else
	200	dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
	201	+ (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
	202
	203	dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
	204	dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
32672c55	205	dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
3c2b9075	206
1921cab1	207	dev_dbg(dev, "%s: date %ptRr\n", __func__, dt);
3c2b9075	208
22652ba7	209	return 0;
3c2b9075 WG	210	}
	211
	212	static int rx8025_set_time(struct device dev, struct rtc_time dt)
	213	{
	214	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	215	u8 date[7];
8c4a4467	216	int ret;
3c2b9075	217
32672c55 AB	218	if ((dt->tm_year < 100) \|\| (dt->tm_year > 199))
32672c55 AB	219	return -EINVAL;
3c2b9075 WG	220
	221	/*
	222	* Here the read-only bits are written as "0". I'm not sure if that
	223	* is sound.
	224	*/
	225	date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
	226	date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
	227	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	228	date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
	229	else
	230	date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
	231	\| bin2bcd((dt->tm_hour + 11) % 12 + 1);
	232
	233	date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
	234	date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
	235	date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
32672c55	236	date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
3c2b9075	237
1921cab1	238	dev_dbg(dev, "%s: write %7ph\n", __func__, date);
3c2b9075	239
8c4a4467 AB	240	ret = rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
	241	if (ret < 0)
	242	return ret;
	243
	244	return rx8025_reset_validity(rx8025->client);
3c2b9075 WG	245	}
3c2b9075 WG	246
6f0a8cfe	247	static int rx8025_init_client(struct i2c_client *client)
3c2b9075 WG	248	{
	249	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
	250	u8 ctrl[2], ctrl2;
	251	int need_clear = 0;
	252	int err;
	253
	254	err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
	255	if (err)
	256	goto out;
	257
	258	/* Keep test bit zero ! */
	259	rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
	260
3c2b9075 WG	261	if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG \| RX8025_BIT_CTRL2_WAFG)) {
	262	dev_warn(&client->dev, "Alarm was detected\n");
	263	need_clear = 1;
	264	}
	265
5c66e1e0	266	if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
3c2b9075 WG	267	need_clear = 1;
3c2b9075 WG	268
6f0a8cfe	269	if (need_clear) {
a27c7bf6	270	ctrl2 = ctrl[1];
8c4a4467	271	ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG \| RX8025_BIT_CTRL2_WAFG \|
3c2b9075	272	RX8025_BIT_CTRL2_DAFG);
3c2b9075 WG	273
	274	err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
	275	}
	276	out:
	277	return err;
	278	}
	279
	280	/* Alarm support */
	281	static int rx8025_read_alarm(struct device dev, struct rtc_wkalrm t)
	282	{
	283	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	284	struct i2c_client *client = rx8025->client;
fd9061fb AB	285	u8 ald[2];
fd9061fb AB	286	int ctrl2, err;
3c2b9075 WG	287
	288	if (client->irq <= 0)
	289	return -EINVAL;
	290
	291	err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
	292	if (err)
	293	return err;
	294
fd9061fb AB	295	ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
	296	if (ctrl2 < 0)
	297	return ctrl2;
3c2b9075 WG	298
	299	dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
	300	__func__, ald[0], ald[1], ctrl2);
	301
	302	/* Hardware alarms precision is 1 minute! */
	303	t->time.tm_sec = 0;
	304	t->time.tm_min = bcd2bin(ald[0] & 0x7f);
	305	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	306	t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
	307	else
	308	t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
	309	+ (ald[1] & 0x20 ? 12 : 0);
	310
862cac15	311	dev_dbg(dev, "%s: date: %ptRr\n", __func__, &t->time);
3c2b9075 WG	312	t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
	313	t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
	314
	315	return err;
	316	}
	317
	318	static int rx8025_set_alarm(struct device dev, struct rtc_wkalrm t)
	319	{
	320	struct i2c_client *client = to_i2c_client(dev);
	321	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	322	u8 ald[2];
	323	int err;
	324
	325	if (client->irq <= 0)
	326	return -EINVAL;
	327
302c5608 AM	328	/*
	329	* Hardware alarm precision is 1 minute!
	330	* round up to nearest minute
	331	*/
	332	if (t->time.tm_sec) {
	333	time64_t alarm_time = rtc_tm_to_time64(&t->time);
	334
	335	alarm_time += 60 - t->time.tm_sec;
	336	rtc_time64_to_tm(alarm_time, &t->time);
	337	}
	338
3c2b9075 WG	339	ald[0] = bin2bcd(t->time.tm_min);
	340	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	341	ald[1] = bin2bcd(t->time.tm_hour);
	342	else
	343	ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
	344	\| bin2bcd((t->time.tm_hour + 11) % 12 + 1);
	345
	346	dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
	347
	348	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
	349	rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
	350	err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
	351	rx8025->ctrl1);
	352	if (err)
	353	return err;
	354	}
	355	err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
	356	if (err)
	357	return err;
	358
	359	if (t->enabled) {
	360	rx8025->ctrl1 \|= RX8025_BIT_CTRL1_DALE;
	361	err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
	362	rx8025->ctrl1);
	363	if (err)
	364	return err;
	365	}
	366
	367	return 0;
	368	}
	369
	370	static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
	371	{
	372	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	373	u8 ctrl1;
	374	int err;
	375
	376	ctrl1 = rx8025->ctrl1;
	377	if (enabled)
	378	ctrl1 \|= RX8025_BIT_CTRL1_DALE;
	379	else
	380	ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
	381
	382	if (ctrl1 != rx8025->ctrl1) {
	383	rx8025->ctrl1 = ctrl1;
	384	err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
	385	rx8025->ctrl1);
	386	if (err)
	387	return err;
	388	}
	389	return 0;
	390	}
	391
34c7b3ac	392	static const struct rtc_class_ops rx8025_rtc_ops = {
3c2b9075 WG	393	.read_time = rx8025_get_time,
	394	.set_time = rx8025_set_time,
	395	.read_alarm = rx8025_read_alarm,
	396	.set_alarm = rx8025_set_alarm,
	397	.alarm_irq_enable = rx8025_alarm_irq_enable,
3c2b9075 WG	398	};
	399
	400	/*
	401	* Clock precision adjustment support
	402	*
	403	* According to the RX8025 SA/NB application manual the frequency and
b770ffd4	404	* temperature characteristics can be approximated using the following
3c2b9075 WG	405	* equation:
	406	*
	407	* df = a * (ut - t)**2
	408	*
	409	* df: Frequency deviation in any temperature
	410	* a : Coefficient = (-35 +-5) * 10**-9
	411	* ut: Ultimate temperature in degree = +25 +-5 degree
	412	* t : Any temperature in degree
	413	*
	414	* Note that the clock adjustment in ppb must be entered (which is
	415	* the negative value of the deviation).
	416	*/
	417	static int rx8025_get_clock_adjust(struct device dev, int adj)
	418	{
	419	struct i2c_client *client = to_i2c_client(dev);
fd9061fb	420	int digoff;
3c2b9075	421
fd9061fb AB	422	digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
	423	if (digoff < 0)
	424	return digoff;
3c2b9075 WG	425
	426	*adj = digoff >= 64 ? digoff - 128 : digoff;
	427	if (*adj > 0)
	428	(*adj)--;
	429	adj = -RX8025_ADJ_RESOLUTION;
	430
	431	return 0;
	432	}
	433
	434	static int rx8025_set_clock_adjust(struct device *dev, int adj)
	435	{
	436	struct i2c_client *client = to_i2c_client(dev);
	437	u8 digoff;
	438	int err;
	439
	440	adj /= -RX8025_ADJ_RESOLUTION;
	441	if (adj > RX8025_ADJ_DATA_MAX)
	442	adj = RX8025_ADJ_DATA_MAX;
	443	else if (adj < RX8025_ADJ_DATA_MIN)
	444	adj = RX8025_ADJ_DATA_MIN;
	445	else if (adj > 0)
	446	adj++;
	447	else if (adj < 0)
	448	adj += 128;
	449	digoff = adj;
	450
	451	err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
	452	if (err)
	453	return err;
	454
	455	dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
	456
	457	return 0;
	458	}
	459
	460	static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
	461	struct device_attribute *attr,
	462	char *buf)
	463	{
	464	int err, adj;
	465
	466	err = rx8025_get_clock_adjust(dev, &adj);
	467	if (err)
	468	return err;
	469
	470	return sprintf(buf, "%d\n", adj);
	471	}
	472
	473	static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
	474	struct device_attribute *attr,
	475	const char *buf, size_t count)
	476	{
	477	int adj, err;
	478
	479	if (sscanf(buf, "%i", &adj) != 1)
	480	return -EINVAL;
	481
	482	err = rx8025_set_clock_adjust(dev, adj);
	483
	484	return err ? err : count;
	485	}
	486
	487	static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO \| S_IWUSR,
	488	rx8025_sysfs_show_clock_adjust,
489	rx8025_sysfs_store_clock_adjust);
490
491	static int rx8025_sysfs_register(struct device *dev)
492	{
493	return device_create_file(dev, &dev_attr_clock_adjust_ppb);
494	}
495
496	static void rx8025_sysfs_unregister(struct device *dev)
497	{
498	device_remove_file(dev, &dev_attr_clock_adjust_ppb);
499	}
500
5a167f45 GKH	501	static int rx8025_probe(struct i2c_client *client,
5a167f45 GKH	502	const struct i2c_device_id *id)
3c2b9075	503	{
110036b4	504	struct i2c_adapter *adapter = client->adapter;
3c2b9075	505	struct rx8025_data *rx8025;
6f0a8cfe	506	int err = 0;
3c2b9075 WG	507
	508	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
	509	\| I2C_FUNC_SMBUS_I2C_BLOCK)) {
	510	dev_err(&adapter->dev,
	511	"doesn't support required functionality\n");
dbcce7cf	512	return -EIO;
3c2b9075 WG	513	}
3c2b9075 WG	514
fac42b41	515	rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
b1f9d790	516	if (!rx8025)
dbcce7cf	517	return -ENOMEM;
3c2b9075 WG	518
	519	rx8025->client = client;
	520	i2c_set_clientdata(client, rx8025);
3c2b9075	521
6f0a8cfe	522	err = rx8025_init_client(client);
3c2b9075	523	if (err)
dbcce7cf	524	return err;
3c2b9075	525
fac42b41	526	rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
3c2b9075 WG	527	&rx8025_rtc_ops, THIS_MODULE);
3c2b9075 WG	528	if (IS_ERR(rx8025->rtc)) {
3c2b9075	529	dev_err(&client->dev, "unable to register the class device\n");
dbcce7cf	530	return PTR_ERR(rx8025->rtc);
3c2b9075 WG	531	}
	532
	533	if (client->irq > 0) {
	534	dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
f0b63a1d	535	err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
0a966c07 AM	536	rx8025_handle_irq,
	537	IRQF_ONESHOT,
	538	"rx8025", client);
3c2b9075	539	if (err) {
8a06513d AB	540	dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
8a06513d AB	541	client->irq = 0;
3c2b9075 WG	542	}
	543	}
	544
3c2b9075 WG	545	rx8025->rtc->max_user_freq = 1;
3c2b9075 WG	546
ef5f4a9e AM	547	/* the rx8025 alarm only supports a minute accuracy */
	548	rx8025->rtc->uie_unsupported = 1;
	549
3c2b9075	550	err = rx8025_sysfs_register(&client->dev);
3c2b9075 WG	551	return err;
	552	}
	553
5a167f45	554	static int rx8025_remove(struct i2c_client *client)
3c2b9075	555	{
3c2b9075	556	rx8025_sysfs_unregister(&client->dev);
3c2b9075 WG	557	return 0;
	558	}
	559
	560	static struct i2c_driver rx8025_driver = {
	561	.driver = {
	562	.name = "rtc-rx8025",
3c2b9075 WG	563	},
3c2b9075 WG	564	.probe = rx8025_probe,
5a167f45	565	.remove = rx8025_remove,
3c2b9075 WG	566	.id_table = rx8025_id,
	567	};
	568
0abc9201	569	module_i2c_driver(rx8025_driver);
3c2b9075 WG	570
	571	MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
	572	MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
	573	MODULE_LICENSE("GPL");