[linux-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

enum rx_model {
	model_rx_unknown,
	model_rx_8025,
	model_rx_8035,
	model_last
};

static const struct i2c_device_id rx8025_id[] = {
	{ "rx8025", model_rx_8025 },
	{ "rx8035", model_rx_8035 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, rx8025_id);

struct rx8025_data {
	struct rtc_device *rtc;
	enum rx_model model;
	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_is_osc_stopped(enum rx_model model, int ctrl2)
{
	int xstp = ctrl2 & RX8025_BIT_CTRL2_XST;
	/* XSTP bit has different polarity on RX-8025 vs RX-8035.
	 * RX-8025: 0 == oscillator stopped
	 * RX-8035: 1 == oscillator stopped
	 */

	if (model == model_rx_8025)
		xstp = !xstp;

	return xstp;
}

static int rx8025_check_validity(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct rx8025_data *drvdata = dev_get_drvdata(dev);
	int ctrl2;
	int xstp;

	ctrl2 = rx8025_read_reg(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;
	}

	xstp = rx8025_is_osc_stopped(drvdata->model, ctrl2);
	if (xstp) {
		dev_warn(dev, "crystal stopped, date is invalid\n");
		return -EINVAL;
	}

	return 0;
}

static int rx8025_reset_validity(struct i2c_client *client)
{
	struct rx8025_data *drvdata = i2c_get_clientdata(client);
	int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);

	if (ctrl2 < 0)
		return ctrl2;

	ctrl2 &= ~(RX8025_BIT_CTRL2_PON | RX8025_BIT_CTRL2_VDET);

	if (drvdata->model == model_rx_8025)
		ctrl2 |= RX8025_BIT_CTRL2_XST;
	else
		ctrl2 &= ~(RX8025_BIT_CTRL2_XST);

	return rx8025_write_reg(client, RX8025_REG_CTRL2,
				ctrl2);
}

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);
	int status, xstp;

	rtc_lock(rx8025->rtc);
	status = rx8025_read_reg(client, RX8025_REG_CTRL2);
	if (status < 0)
		goto out;

	xstp = rx8025_is_osc_stopped(rx8025->model, status);
	if (xstp)
		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:
	rtc_unlock(rx8025->rtc);

	return IRQ_HANDLED;
}

static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
{
	struct i2c_client *client = to_i2c_client(dev);
	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(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 i2c_client *client = to_i2c_client(dev);
	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(client, RX8025_REG_SEC, 7, date);
	if (ret < 0)
		return ret;

	return rx8025_reset_validity(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(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 i2c_client *client = to_i2c_client(dev);
	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	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(client, RX8025_REG_CTRL1,
				       rx8025->ctrl1);
		if (err)
			return err;
	}
	err = rx8025_write_regs(client, RX8025_REG_ALDMIN, 2, ald);
	if (err)
		return err;

	if (t->enabled) {
		rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
		err = rx8025_write_reg(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 i2c_client *client = to_i2c_client(dev);
	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(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;

	i2c_set_clientdata(client, rx8025);

	if (id)
		rx8025->model = id->driver_data;

	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
f120e2e3 MM	63	enum rx_model {
	64	model_rx_unknown,
	65	model_rx_8025,
	66	model_rx_8035,
	67	model_last
	68	};
	69
3c2b9075	70	static const struct i2c_device_id rx8025_id[] = {
f120e2e3 MM	71	{ "rx8025", model_rx_8025 },
f120e2e3 MM	72	{ "rx8035", model_rx_8035 },
3c2b9075 WG	73	{ }
	74	};
	75	MODULE_DEVICE_TABLE(i2c, rx8025_id);
	76
	77	struct rx8025_data {
3c2b9075	78	struct rtc_device *rtc;
f120e2e3	79	enum rx_model model;
3c2b9075	80	u8 ctrl1;
3c2b9075 WG	81	};
3c2b9075 WG	82
fd9061fb	83	static s32 rx8025_read_reg(const struct i2c_client *client, u8 number)
3c2b9075	84	{
fd9061fb	85	return i2c_smbus_read_byte_data(client, number << 4);
3c2b9075 WG	86	}
3c2b9075 WG	87
fd9061fb AB	88	static int rx8025_read_regs(const struct i2c_client *client,
fd9061fb AB	89	u8 number, u8 length, u8 *values)
3c2b9075	90	{
fd9061fb AB	91	int ret = i2c_smbus_read_i2c_block_data(client, number << 4, length,
	92	values);
	93	if (ret != length)
3c2b9075	94	return ret < 0 ? ret : -EIO;
3c2b9075 WG	95
	96	return 0;
	97	}
	98
fd9061fb AB	99	static s32 rx8025_write_reg(const struct i2c_client *client, u8 number,
fd9061fb AB	100	u8 value)
3c2b9075	101	{
fd9061fb	102	return i2c_smbus_write_byte_data(client, number << 4, value);
3c2b9075 WG	103	}
3c2b9075 WG	104
fd9061fb AB	105	static s32 rx8025_write_regs(const struct i2c_client *client,
fd9061fb AB	106	u8 number, u8 length, const u8 *values)
3c2b9075	107	{
fd9061fb AB	108	return i2c_smbus_write_i2c_block_data(client, number << 4,
fd9061fb AB	109	length, values);
3c2b9075 WG	110	}
3c2b9075 WG	111
f120e2e3 MM	112	static int rx8025_is_osc_stopped(enum rx_model model, int ctrl2)
	113	{
	114	int xstp = ctrl2 & RX8025_BIT_CTRL2_XST;
	115	/* XSTP bit has different polarity on RX-8025 vs RX-8035.
	116	* RX-8025: 0 == oscillator stopped
	117	* RX-8035: 1 == oscillator stopped
	118	*/
	119
	120	if (model == model_rx_8025)
	121	xstp = !xstp;
	122
	123	return xstp;
	124	}
	125
efbbb4fd AB	126	static int rx8025_check_validity(struct device *dev)
efbbb4fd AB	127	{
47a3c048	128	struct i2c_client *client = to_i2c_client(dev);
f120e2e3	129	struct rx8025_data *drvdata = dev_get_drvdata(dev);
efbbb4fd	130	int ctrl2;
f120e2e3	131	int xstp;
efbbb4fd	132
47a3c048	133	ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
efbbb4fd AB	134	if (ctrl2 < 0)
	135	return ctrl2;
	136
	137	if (ctrl2 & RX8025_BIT_CTRL2_VDET)
	138	dev_warn(dev, "power voltage drop detected\n");
	139
	140	if (ctrl2 & RX8025_BIT_CTRL2_PON) {
	141	dev_warn(dev, "power-on reset detected, date is invalid\n");
	142	return -EINVAL;
	143	}
	144
f120e2e3 MM	145	xstp = rx8025_is_osc_stopped(drvdata->model, ctrl2);
f120e2e3 MM	146	if (xstp) {
efbbb4fd AB	147	dev_warn(dev, "crystal stopped, date is invalid\n");
	148	return -EINVAL;
	149	}
	150
	151	return 0;
	152	}
	153
8c4a4467 AB	154	static int rx8025_reset_validity(struct i2c_client *client)
8c4a4467 AB	155	{
f120e2e3	156	struct rx8025_data *drvdata = i2c_get_clientdata(client);
8c4a4467 AB	157	int ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
	158
	159	if (ctrl2 < 0)
	160	return ctrl2;
	161
	162	ctrl2 &= ~(RX8025_BIT_CTRL2_PON \| RX8025_BIT_CTRL2_VDET);
	163
f120e2e3 MM	164	if (drvdata->model == model_rx_8025)
	165	ctrl2 \|= RX8025_BIT_CTRL2_XST;
	166	else
	167	ctrl2 &= ~(RX8025_BIT_CTRL2_XST);
	168
8c4a4467	169	return rx8025_write_reg(client, RX8025_REG_CTRL2,
f120e2e3	170	ctrl2);
8c4a4467 AB	171	}
8c4a4467 AB	172
b6a57c95	173	static irqreturn_t rx8025_handle_irq(int irq, void *dev_id)
3c2b9075 WG	174	{
	175	struct i2c_client *client = dev_id;
	176	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
f120e2e3	177	int status, xstp;
3c2b9075	178
31247546	179	rtc_lock(rx8025->rtc);
fd9061fb AB	180	status = rx8025_read_reg(client, RX8025_REG_CTRL2);
fd9061fb AB	181	if (status < 0)
3c2b9075 WG	182	goto out;
3c2b9075 WG	183
f120e2e3 MM	184	xstp = rx8025_is_osc_stopped(rx8025->model, status);
f120e2e3 MM	185	if (xstp)
3c2b9075 WG	186	dev_warn(&client->dev, "Oscillation stop was detected,"
	187	"you may have to readjust the clock\n");
	188
	189	if (status & RX8025_BIT_CTRL2_CTFG) {
	190	/* periodic */
	191	status &= ~RX8025_BIT_CTRL2_CTFG;
3c2b9075	192	rtc_update_irq(rx8025->rtc, 1, RTC_PF \| RTC_IRQF);
3c2b9075 WG	193	}
	194
	195	if (status & RX8025_BIT_CTRL2_DAFG) {
	196	/* alarm */
	197	status &= RX8025_BIT_CTRL2_DAFG;
	198	if (rx8025_write_reg(client, RX8025_REG_CTRL1,
	199	rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
	200	goto out;
3c2b9075	201	rtc_update_irq(rx8025->rtc, 1, RTC_AF \| RTC_IRQF);
3c2b9075 WG	202	}
3c2b9075 WG	203
3c2b9075	204	out:
31247546	205	rtc_unlock(rx8025->rtc);
9dbe3852	206
b6a57c95	207	return IRQ_HANDLED;
3c2b9075 WG	208	}
	209
	210	static int rx8025_get_time(struct device dev, struct rtc_time dt)
	211	{
47a3c048	212	struct i2c_client *client = to_i2c_client(dev);
3c2b9075	213	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
fd9061fb	214	u8 date[7];
efbbb4fd	215	int err;
6f0a8cfe	216
efbbb4fd AB	217	err = rx8025_check_validity(dev);
	218	if (err)
	219	return err;
6f0a8cfe	220
47a3c048	221	err = rx8025_read_regs(client, RX8025_REG_SEC, 7, date);
3c2b9075 WG	222	if (err)
	223	return err;
	224
1921cab1	225	dev_dbg(dev, "%s: read %7ph\n", __func__, date);
3c2b9075 WG	226
	227	dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
	228	dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
	229	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	230	dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
	231	else
	232	dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
	233	+ (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
	234
	235	dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
	236	dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
32672c55	237	dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
3c2b9075	238
1921cab1	239	dev_dbg(dev, "%s: date %ptRr\n", __func__, dt);
3c2b9075	240
22652ba7	241	return 0;
3c2b9075 WG	242	}
	243
	244	static int rx8025_set_time(struct device dev, struct rtc_time dt)
	245	{
47a3c048	246	struct i2c_client *client = to_i2c_client(dev);
3c2b9075 WG	247	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
3c2b9075 WG	248	u8 date[7];
8c4a4467	249	int ret;
3c2b9075	250
32672c55 AB	251	if ((dt->tm_year < 100) \|\| (dt->tm_year > 199))
32672c55 AB	252	return -EINVAL;
3c2b9075 WG	253
	254	/*
	255	* Here the read-only bits are written as "0". I'm not sure if that
	256	* is sound.
	257	*/
	258	date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
	259	date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
	260	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	261	date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
	262	else
	263	date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
	264	\| bin2bcd((dt->tm_hour + 11) % 12 + 1);
	265
	266	date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
	267	date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
	268	date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
32672c55	269	date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
3c2b9075	270
1921cab1	271	dev_dbg(dev, "%s: write %7ph\n", __func__, date);
3c2b9075	272
47a3c048	273	ret = rx8025_write_regs(client, RX8025_REG_SEC, 7, date);
8c4a4467 AB	274	if (ret < 0)
	275	return ret;
	276
47a3c048	277	return rx8025_reset_validity(client);
3c2b9075 WG	278	}
3c2b9075 WG	279
6f0a8cfe	280	static int rx8025_init_client(struct i2c_client *client)
3c2b9075 WG	281	{
	282	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
	283	u8 ctrl[2], ctrl2;
	284	int need_clear = 0;
	285	int err;
	286
47a3c048	287	err = rx8025_read_regs(client, RX8025_REG_CTRL1, 2, ctrl);
3c2b9075 WG	288	if (err)
	289	goto out;
	290
	291	/* Keep test bit zero ! */
	292	rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
	293
3c2b9075 WG	294	if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG \| RX8025_BIT_CTRL2_WAFG)) {
	295	dev_warn(&client->dev, "Alarm was detected\n");
	296	need_clear = 1;
	297	}
	298
5c66e1e0	299	if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
3c2b9075 WG	300	need_clear = 1;
3c2b9075 WG	301
6f0a8cfe	302	if (need_clear) {
a27c7bf6	303	ctrl2 = ctrl[1];
8c4a4467	304	ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG \| RX8025_BIT_CTRL2_WAFG \|
3c2b9075	305	RX8025_BIT_CTRL2_DAFG);
3c2b9075 WG	306
	307	err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
	308	}
	309	out:
	310	return err;
	311	}
	312
	313	/* Alarm support */
	314	static int rx8025_read_alarm(struct device dev, struct rtc_wkalrm t)
	315	{
47a3c048	316	struct i2c_client *client = to_i2c_client(dev);
3c2b9075	317	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
fd9061fb AB	318	u8 ald[2];
fd9061fb AB	319	int ctrl2, err;
3c2b9075 WG	320
	321	if (client->irq <= 0)
	322	return -EINVAL;
	323
	324	err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
	325	if (err)
	326	return err;
	327
fd9061fb AB	328	ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
	329	if (ctrl2 < 0)
	330	return ctrl2;
3c2b9075 WG	331
	332	dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
	333	__func__, ald[0], ald[1], ctrl2);
	334
	335	/* Hardware alarms precision is 1 minute! */
	336	t->time.tm_sec = 0;
	337	t->time.tm_min = bcd2bin(ald[0] & 0x7f);
	338	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	339	t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
	340	else
	341	t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
	342	+ (ald[1] & 0x20 ? 12 : 0);
	343
862cac15	344	dev_dbg(dev, "%s: date: %ptRr\n", __func__, &t->time);
3c2b9075 WG	345	t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
	346	t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
	347
	348	return err;
	349	}
	350
	351	static int rx8025_set_alarm(struct device dev, struct rtc_wkalrm t)
	352	{
	353	struct i2c_client *client = to_i2c_client(dev);
	354	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	355	u8 ald[2];
	356	int err;
	357
	358	if (client->irq <= 0)
	359	return -EINVAL;
	360
302c5608 AM	361	/*
	362	* Hardware alarm precision is 1 minute!
	363	* round up to nearest minute
	364	*/
	365	if (t->time.tm_sec) {
	366	time64_t alarm_time = rtc_tm_to_time64(&t->time);
	367
	368	alarm_time += 60 - t->time.tm_sec;
	369	rtc_time64_to_tm(alarm_time, &t->time);
	370	}
	371
3c2b9075 WG	372	ald[0] = bin2bcd(t->time.tm_min);
	373	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	374	ald[1] = bin2bcd(t->time.tm_hour);
	375	else
	376	ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
	377	\| bin2bcd((t->time.tm_hour + 11) % 12 + 1);
	378
	379	dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
	380
	381	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
	382	rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
47a3c048	383	err = rx8025_write_reg(client, RX8025_REG_CTRL1,
3c2b9075 WG	384	rx8025->ctrl1);
	385	if (err)
	386	return err;
	387	}
47a3c048	388	err = rx8025_write_regs(client, RX8025_REG_ALDMIN, 2, ald);
3c2b9075 WG	389	if (err)
	390	return err;
	391
	392	if (t->enabled) {
	393	rx8025->ctrl1 \|= RX8025_BIT_CTRL1_DALE;
47a3c048	394	err = rx8025_write_reg(client, RX8025_REG_CTRL1,
3c2b9075 WG	395	rx8025->ctrl1);
	396	if (err)
	397	return err;
	398	}
	399
	400	return 0;
	401	}
	402
	403	static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
	404	{
47a3c048	405	struct i2c_client *client = to_i2c_client(dev);
3c2b9075 WG	406	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	407	u8 ctrl1;
	408	int err;
	409
	410	ctrl1 = rx8025->ctrl1;
	411	if (enabled)
	412	ctrl1 \|= RX8025_BIT_CTRL1_DALE;
	413	else
	414	ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
	415
	416	if (ctrl1 != rx8025->ctrl1) {
	417	rx8025->ctrl1 = ctrl1;
47a3c048	418	err = rx8025_write_reg(client, RX8025_REG_CTRL1,
3c2b9075 WG	419	rx8025->ctrl1);
	420	if (err)
	421	return err;
	422	}
	423	return 0;
	424	}
	425
34c7b3ac	426	static const struct rtc_class_ops rx8025_rtc_ops = {
3c2b9075 WG	427	.read_time = rx8025_get_time,
	428	.set_time = rx8025_set_time,
	429	.read_alarm = rx8025_read_alarm,
	430	.set_alarm = rx8025_set_alarm,
	431	.alarm_irq_enable = rx8025_alarm_irq_enable,
3c2b9075 WG	432	};
	433
	434	/*
	435	* Clock precision adjustment support
	436	*
	437	* According to the RX8025 SA/NB application manual the frequency and
b770ffd4	438	* temperature characteristics can be approximated using the following
3c2b9075 WG	439	* equation:
	440	*
	441	* df = a * (ut - t)**2
	442	*
	443	* df: Frequency deviation in any temperature
	444	* a : Coefficient = (-35 +-5) * 10**-9
	445	* ut: Ultimate temperature in degree = +25 +-5 degree
	446	* t : Any temperature in degree
	447	*
	448	* Note that the clock adjustment in ppb must be entered (which is
	449	* the negative value of the deviation).
	450	*/
	451	static int rx8025_get_clock_adjust(struct device dev, int adj)
	452	{
	453	struct i2c_client *client = to_i2c_client(dev);
fd9061fb	454	int digoff;
3c2b9075	455
fd9061fb AB	456	digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
	457	if (digoff < 0)
	458	return digoff;
3c2b9075 WG	459
	460	*adj = digoff >= 64 ? digoff - 128 : digoff;
	461	if (*adj > 0)
	462	(*adj)--;
	463	adj = -RX8025_ADJ_RESOLUTION;
	464
	465	return 0;
	466	}
	467
	468	static int rx8025_set_clock_adjust(struct device *dev, int adj)
	469	{
	470	struct i2c_client *client = to_i2c_client(dev);
	471	u8 digoff;
	472	int err;
	473
	474	adj /= -RX8025_ADJ_RESOLUTION;
	475	if (adj > RX8025_ADJ_DATA_MAX)
	476	adj = RX8025_ADJ_DATA_MAX;
	477	else if (adj < RX8025_ADJ_DATA_MIN)
	478	adj = RX8025_ADJ_DATA_MIN;
	479	else if (adj > 0)
	480	adj++;
	481	else if (adj < 0)
	482	adj += 128;
	483	digoff = adj;
	484
	485	err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
	486	if (err)
	487	return err;
	488
	489	dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
	490
	491	return 0;
	492	}
	493
	494	static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
	495	struct device_attribute *attr,
	496	char *buf)
	497	{
	498	int err, adj;
	499
	500	err = rx8025_get_clock_adjust(dev, &adj);
	501	if (err)
	502	return err;
	503
	504	return sprintf(buf, "%d\n", adj);
	505	}
	506
	507	static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
	508	struct device_attribute *attr,
	509	const char *buf, size_t count)
	510	{
	511	int adj, err;
	512
	513	if (sscanf(buf, "%i", &adj) != 1)
	514	return -EINVAL;
	515
	516	err = rx8025_set_clock_adjust(dev, adj);
	517
	518	return err ? err : count;
	519	}
	520
	521	static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO \| S_IWUSR,
	522	rx8025_sysfs_show_clock_adjust,
523	rx8025_sysfs_store_clock_adjust);
524
525	static int rx8025_sysfs_register(struct device *dev)
526	{
527	return device_create_file(dev, &dev_attr_clock_adjust_ppb);
528	}
529
530	static void rx8025_sysfs_unregister(struct device *dev)
531	{
532	device_remove_file(dev, &dev_attr_clock_adjust_ppb);
533	}
534
5a167f45 GKH	535	static int rx8025_probe(struct i2c_client *client,
5a167f45 GKH	536	const struct i2c_device_id *id)
3c2b9075	537	{
110036b4	538	struct i2c_adapter *adapter = client->adapter;
3c2b9075	539	struct rx8025_data *rx8025;
6f0a8cfe	540	int err = 0;
3c2b9075 WG	541
	542	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
	543	\| I2C_FUNC_SMBUS_I2C_BLOCK)) {
	544	dev_err(&adapter->dev,
	545	"doesn't support required functionality\n");
dbcce7cf	546	return -EIO;
3c2b9075 WG	547	}
3c2b9075 WG	548
fac42b41	549	rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
b1f9d790	550	if (!rx8025)
dbcce7cf	551	return -ENOMEM;
3c2b9075	552
3c2b9075	553	i2c_set_clientdata(client, rx8025);
3c2b9075	554
f120e2e3 MM	555	if (id)
	556	rx8025->model = id->driver_data;
	557
6f0a8cfe	558	err = rx8025_init_client(client);
3c2b9075	559	if (err)
dbcce7cf	560	return err;
3c2b9075	561
fac42b41	562	rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
3c2b9075 WG	563	&rx8025_rtc_ops, THIS_MODULE);
3c2b9075 WG	564	if (IS_ERR(rx8025->rtc)) {
3c2b9075	565	dev_err(&client->dev, "unable to register the class device\n");
dbcce7cf	566	return PTR_ERR(rx8025->rtc);
3c2b9075 WG	567	}
	568
	569	if (client->irq > 0) {
	570	dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
f0b63a1d	571	err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
0a966c07 AM	572	rx8025_handle_irq,
	573	IRQF_ONESHOT,
	574	"rx8025", client);
3c2b9075	575	if (err) {
8a06513d AB	576	dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
8a06513d AB	577	client->irq = 0;
3c2b9075 WG	578	}
	579	}
	580
3c2b9075 WG	581	rx8025->rtc->max_user_freq = 1;
3c2b9075 WG	582
ef5f4a9e AM	583	/* the rx8025 alarm only supports a minute accuracy */
	584	rx8025->rtc->uie_unsupported = 1;
	585
3c2b9075	586	err = rx8025_sysfs_register(&client->dev);
3c2b9075 WG	587	return err;
	588	}
	589
5a167f45	590	static int rx8025_remove(struct i2c_client *client)
3c2b9075	591	{
3c2b9075	592	rx8025_sysfs_unregister(&client->dev);
3c2b9075 WG	593	return 0;
	594	}
	595
	596	static struct i2c_driver rx8025_driver = {
	597	.driver = {
	598	.name = "rtc-rx8025",
3c2b9075 WG	599	},
3c2b9075 WG	600	.probe = rx8025_probe,
5a167f45	601	.remove = rx8025_remove,
3c2b9075 WG	602	.id_table = rx8025_id,
	603	};
	604
0abc9201	605	module_i2c_driver(rx8025_driver);
3c2b9075 WG	606
	607	MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
	608	MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
	609	MODULE_LICENSE("GPL");