[mirror_ubuntu-jammy-kernel.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 %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 = 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
1921cab1	196	dev_dbg(dev, "%s: read %7ph\n", __func__, date);
3c2b9075 WG	197
	198	dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
	199	dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
	200	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	201	dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
	202	else
	203	dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
	204	+ (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
	205
	206	dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
	207	dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
32672c55	208	dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
3c2b9075	209
1921cab1	210	dev_dbg(dev, "%s: date %ptRr\n", __func__, dt);
3c2b9075	211
22652ba7	212	return 0;
3c2b9075 WG	213	}
	214
	215	static int rx8025_set_time(struct device dev, struct rtc_time dt)
	216	{
	217	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	218	u8 date[7];
8c4a4467	219	int ret;
3c2b9075	220
32672c55 AB	221	if ((dt->tm_year < 100) \|\| (dt->tm_year > 199))
32672c55 AB	222	return -EINVAL;
3c2b9075 WG	223
	224	/*
	225	* Here the read-only bits are written as "0". I'm not sure if that
	226	* is sound.
	227	*/
	228	date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
	229	date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
	230	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	231	date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
	232	else
	233	date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
	234	\| bin2bcd((dt->tm_hour + 11) % 12 + 1);
	235
	236	date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
	237	date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
	238	date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
32672c55	239	date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
3c2b9075	240
1921cab1	241	dev_dbg(dev, "%s: write %7ph\n", __func__, date);
3c2b9075	242
8c4a4467 AB	243	ret = rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
	244	if (ret < 0)
	245	return ret;
	246
	247	return rx8025_reset_validity(rx8025->client);
3c2b9075 WG	248	}
3c2b9075 WG	249
6f0a8cfe	250	static int rx8025_init_client(struct i2c_client *client)
3c2b9075 WG	251	{
	252	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
	253	u8 ctrl[2], ctrl2;
	254	int need_clear = 0;
	255	int err;
	256
	257	err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
	258	if (err)
	259	goto out;
	260
	261	/* Keep test bit zero ! */
	262	rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
	263
3c2b9075 WG	264	if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG \| RX8025_BIT_CTRL2_WAFG)) {
	265	dev_warn(&client->dev, "Alarm was detected\n");
	266	need_clear = 1;
	267	}
	268
5c66e1e0	269	if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
3c2b9075 WG	270	need_clear = 1;
3c2b9075 WG	271
6f0a8cfe	272	if (need_clear) {
a27c7bf6	273	ctrl2 = ctrl[1];
8c4a4467	274	ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG \| RX8025_BIT_CTRL2_WAFG \|
3c2b9075	275	RX8025_BIT_CTRL2_DAFG);
3c2b9075 WG	276
	277	err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
	278	}
	279	out:
	280	return err;
	281	}
	282
	283	/* Alarm support */
	284	static int rx8025_read_alarm(struct device dev, struct rtc_wkalrm t)
	285	{
	286	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	287	struct i2c_client *client = rx8025->client;
fd9061fb AB	288	u8 ald[2];
fd9061fb AB	289	int ctrl2, err;
3c2b9075 WG	290
	291	if (client->irq <= 0)
	292	return -EINVAL;
	293
	294	err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
	295	if (err)
	296	return err;
	297
fd9061fb AB	298	ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
	299	if (ctrl2 < 0)
	300	return ctrl2;
3c2b9075 WG	301
	302	dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
	303	__func__, ald[0], ald[1], ctrl2);
	304
	305	/* Hardware alarms precision is 1 minute! */
	306	t->time.tm_sec = 0;
	307	t->time.tm_min = bcd2bin(ald[0] & 0x7f);
	308	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	309	t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
	310	else
	311	t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
	312	+ (ald[1] & 0x20 ? 12 : 0);
	313
862cac15	314	dev_dbg(dev, "%s: date: %ptRr\n", __func__, &t->time);
3c2b9075 WG	315	t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
	316	t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
	317
	318	return err;
	319	}
	320
	321	static int rx8025_set_alarm(struct device dev, struct rtc_wkalrm t)
	322	{
	323	struct i2c_client *client = to_i2c_client(dev);
	324	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	325	u8 ald[2];
	326	int err;
	327
	328	if (client->irq <= 0)
	329	return -EINVAL;
	330
302c5608 AM	331	/*
	332	* Hardware alarm precision is 1 minute!
	333	* round up to nearest minute
	334	*/
	335	if (t->time.tm_sec) {
	336	time64_t alarm_time = rtc_tm_to_time64(&t->time);
	337
	338	alarm_time += 60 - t->time.tm_sec;
	339	rtc_time64_to_tm(alarm_time, &t->time);
	340	}
	341
3c2b9075 WG	342	ald[0] = bin2bcd(t->time.tm_min);
	343	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	344	ald[1] = bin2bcd(t->time.tm_hour);
	345	else
	346	ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
	347	\| bin2bcd((t->time.tm_hour + 11) % 12 + 1);
	348
	349	dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
	350
	351	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
	352	rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
	353	err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
	354	rx8025->ctrl1);
	355	if (err)
	356	return err;
	357	}
	358	err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
	359	if (err)
	360	return err;
	361
	362	if (t->enabled) {
	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
	370	return 0;
	371	}
	372
	373	static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
	374	{
	375	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	376	u8 ctrl1;
	377	int err;
	378
	379	ctrl1 = rx8025->ctrl1;
	380	if (enabled)
	381	ctrl1 \|= RX8025_BIT_CTRL1_DALE;
	382	else
	383	ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
	384
	385	if (ctrl1 != rx8025->ctrl1) {
	386	rx8025->ctrl1 = ctrl1;
	387	err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
	388	rx8025->ctrl1);
	389	if (err)
	390	return err;
	391	}
	392	return 0;
	393	}
	394
34c7b3ac	395	static const struct rtc_class_ops rx8025_rtc_ops = {
3c2b9075 WG	396	.read_time = rx8025_get_time,
	397	.set_time = rx8025_set_time,
	398	.read_alarm = rx8025_read_alarm,
	399	.set_alarm = rx8025_set_alarm,
	400	.alarm_irq_enable = rx8025_alarm_irq_enable,
3c2b9075 WG	401	};
	402
	403	/*
	404	* Clock precision adjustment support
	405	*
	406	* According to the RX8025 SA/NB application manual the frequency and
b770ffd4	407	* temperature characteristics can be approximated using the following
3c2b9075 WG	408	* equation:
	409	*
	410	* df = a * (ut - t)**2
	411	*
	412	* df: Frequency deviation in any temperature
	413	* a : Coefficient = (-35 +-5) * 10**-9
	414	* ut: Ultimate temperature in degree = +25 +-5 degree
	415	* t : Any temperature in degree
	416	*
	417	* Note that the clock adjustment in ppb must be entered (which is
	418	* the negative value of the deviation).
	419	*/
	420	static int rx8025_get_clock_adjust(struct device dev, int adj)
	421	{
	422	struct i2c_client *client = to_i2c_client(dev);
fd9061fb	423	int digoff;
3c2b9075	424
fd9061fb AB	425	digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
	426	if (digoff < 0)
	427	return digoff;
3c2b9075 WG	428
	429	*adj = digoff >= 64 ? digoff - 128 : digoff;
	430	if (*adj > 0)
	431	(*adj)--;
	432	adj = -RX8025_ADJ_RESOLUTION;
	433
	434	return 0;
	435	}
	436
	437	static int rx8025_set_clock_adjust(struct device *dev, int adj)
	438	{
	439	struct i2c_client *client = to_i2c_client(dev);
	440	u8 digoff;
	441	int err;
	442
	443	adj /= -RX8025_ADJ_RESOLUTION;
	444	if (adj > RX8025_ADJ_DATA_MAX)
	445	adj = RX8025_ADJ_DATA_MAX;
	446	else if (adj < RX8025_ADJ_DATA_MIN)
	447	adj = RX8025_ADJ_DATA_MIN;
	448	else if (adj > 0)
	449	adj++;
	450	else if (adj < 0)
	451	adj += 128;
	452	digoff = adj;
	453
	454	err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
	455	if (err)
	456	return err;
	457
	458	dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
	459
	460	return 0;
	461	}
	462
	463	static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
	464	struct device_attribute *attr,
	465	char *buf)
	466	{
	467	int err, adj;
	468
	469	err = rx8025_get_clock_adjust(dev, &adj);
	470	if (err)
	471	return err;
	472
	473	return sprintf(buf, "%d\n", adj);
	474	}
	475
	476	static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
	477	struct device_attribute *attr,
	478	const char *buf, size_t count)
	479	{
	480	int adj, err;
	481
	482	if (sscanf(buf, "%i", &adj) != 1)
	483	return -EINVAL;
	484
	485	err = rx8025_set_clock_adjust(dev, adj);
	486
	487	return err ? err : count;
	488	}
	489
	490	static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO \| S_IWUSR,
	491	rx8025_sysfs_show_clock_adjust,
492	rx8025_sysfs_store_clock_adjust);
493
494	static int rx8025_sysfs_register(struct device *dev)
495	{
496	return device_create_file(dev, &dev_attr_clock_adjust_ppb);
497	}
498
499	static void rx8025_sysfs_unregister(struct device *dev)
500	{
501	device_remove_file(dev, &dev_attr_clock_adjust_ppb);
502	}
503
5a167f45 GKH	504	static int rx8025_probe(struct i2c_client *client,
5a167f45 GKH	505	const struct i2c_device_id *id)
3c2b9075 WG	506	{
	507	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
	508	struct rx8025_data *rx8025;
6f0a8cfe	509	int err = 0;
3c2b9075 WG	510
	511	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
	512	\| I2C_FUNC_SMBUS_I2C_BLOCK)) {
	513	dev_err(&adapter->dev,
	514	"doesn't support required functionality\n");
dbcce7cf	515	return -EIO;
3c2b9075 WG	516	}
3c2b9075 WG	517
fac42b41	518	rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
b1f9d790	519	if (!rx8025)
dbcce7cf	520	return -ENOMEM;
3c2b9075 WG	521
	522	rx8025->client = client;
	523	i2c_set_clientdata(client, rx8025);
3c2b9075	524
6f0a8cfe	525	err = rx8025_init_client(client);
3c2b9075	526	if (err)
dbcce7cf	527	return err;
3c2b9075	528
fac42b41	529	rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
3c2b9075 WG	530	&rx8025_rtc_ops, THIS_MODULE);
3c2b9075 WG	531	if (IS_ERR(rx8025->rtc)) {
3c2b9075	532	dev_err(&client->dev, "unable to register the class device\n");
dbcce7cf	533	return PTR_ERR(rx8025->rtc);
3c2b9075 WG	534	}
	535
	536	if (client->irq > 0) {
	537	dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
f0b63a1d	538	err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
0a966c07 AM	539	rx8025_handle_irq,
	540	IRQF_ONESHOT,
	541	"rx8025", client);
3c2b9075	542	if (err) {
8a06513d AB	543	dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
8a06513d AB	544	client->irq = 0;
3c2b9075 WG	545	}
	546	}
	547
3c2b9075 WG	548	rx8025->rtc->max_user_freq = 1;
3c2b9075 WG	549
ef5f4a9e AM	550	/* the rx8025 alarm only supports a minute accuracy */
	551	rx8025->rtc->uie_unsupported = 1;
	552
3c2b9075	553	err = rx8025_sysfs_register(&client->dev);
3c2b9075 WG	554	return err;
	555	}
	556
5a167f45	557	static int rx8025_remove(struct i2c_client *client)
3c2b9075	558	{
3c2b9075	559	rx8025_sysfs_unregister(&client->dev);
3c2b9075 WG	560	return 0;
	561	}
	562
	563	static struct i2c_driver rx8025_driver = {
	564	.driver = {
	565	.name = "rtc-rx8025",
3c2b9075 WG	566	},
3c2b9075 WG	567	.probe = rx8025_probe,
5a167f45	568	.remove = rx8025_remove,
3c2b9075 WG	569	.id_table = rx8025_id,
	570	};
	571
0abc9201	572	module_i2c_driver(rx8025_driver);
3c2b9075 WG	573
	574	MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
	575	MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
	576	MODULE_LICENSE("GPL");