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

/*
 * Driver for Epson's RTC module RX-8025 SA/NB
 *
 * Copyright (C) 2009 Wolfgang Grandegger <wg@grandegger.com>
 *
 * Copyright (C) 2005 by Digi International Inc.
 * All rights reserved.
 *
 * Modified by fengjh at rising.com.cn
 * <http://lists.lm-sensors.org/mailman/listinfo/lm-sensors>
 * 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);
	int status;

	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:
	return IRQ_HANDLED;
}

static int rx8025_get_time(struct device *dev, struct rtc_time *dt)
{
	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	u8 date[7];
	int err;

	err = rx8025_check_validity(dev);
	if (err)
		return err;

	err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
	if (err)
		return err;

	dev_dbg(dev, "%s: read 0x%02x 0x%02x "
		"0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
		date[0], date[1], date[2], date[3], date[4],
		date[5], date[6]);

	dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
	dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
		dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
	else
		dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
			+ (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);

	dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
	dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
	dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;

	dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
		dt->tm_sec, dt->tm_min, dt->tm_hour,
		dt->tm_mday, dt->tm_mon, dt->tm_year);

	return rtc_valid_tm(dt);
}

static int rx8025_set_time(struct device *dev, struct rtc_time *dt)
{
	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	u8 date[7];
	int ret;

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

	/*
	 * Here the read-only bits are written as "0".  I'm not sure if that
	 * is sound.
	 */
	date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
	date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
		date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
	else
		date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
			| bin2bcd((dt->tm_hour + 11) % 12 + 1);

	date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
	date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
	date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
	date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);

	dev_dbg(dev,
		"%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
		__func__,
		date[0], date[1], date[2], date[3], date[4], date[5], date[6]);

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

	return rx8025_reset_validity(rx8025->client);
}

static int rx8025_init_client(struct i2c_client *client)
{
	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
	u8 ctrl[2], ctrl2;
	int need_clear = 0;
	int err;

	err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
	if (err)
		goto out;

	/* Keep test bit zero ! */
	rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;

	if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG | RX8025_BIT_CTRL2_WAFG)) {
		dev_warn(&client->dev, "Alarm was detected\n");
		need_clear = 1;
	}

	if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
		need_clear = 1;

	if (need_clear) {
		ctrl2 = ctrl[1];
		ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG | RX8025_BIT_CTRL2_WAFG |
			   RX8025_BIT_CTRL2_DAFG);

		err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
	}
out:
	return err;
}

/* Alarm support */
static int rx8025_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	struct i2c_client *client = rx8025->client;
	u8 ald[2];
	int ctrl2, err;

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

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

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

	dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
		__func__, ald[0], ald[1], ctrl2);

	/* Hardware alarms precision is 1 minute! */
	t->time.tm_sec = 0;
	t->time.tm_min = bcd2bin(ald[0] & 0x7f);
	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
		t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
	else
		t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
			+ (ald[1] & 0x20 ? 12 : 0);

	t->time.tm_wday = -1;
	t->time.tm_mday = -1;
	t->time.tm_mon = -1;
	t->time.tm_year = -1;

	dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
		__func__,
		t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
		t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
	t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
	t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;

	return err;
}

static int rx8025_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	u8 ald[2];
	int err;

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

	/* Hardware alarm precision is 1 minute! */
	ald[0] = bin2bcd(t->time.tm_min);
	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
		ald[1] = bin2bcd(t->time.tm_hour);
	else
		ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
			| bin2bcd((t->time.tm_hour + 11) % 12 + 1);

	dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);

	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
		rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
		err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
				       rx8025->ctrl1);
		if (err)
			return err;
	}
	err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
	if (err)
		return err;

	if (t->enabled) {
		rx8025->ctrl1 |= RX8025_BIT_CTRL1_DALE;
		err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
				       rx8025->ctrl1);
		if (err)
			return err;
	}

	return 0;
}

static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	u8 ctrl1;
	int err;

	ctrl1 = rx8025->ctrl1;
	if (enabled)
		ctrl1 |= RX8025_BIT_CTRL1_DALE;
	else
		ctrl1 &= ~RX8025_BIT_CTRL1_DALE;

	if (ctrl1 != rx8025->ctrl1) {
		rx8025->ctrl1 = ctrl1;
		err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
				       rx8025->ctrl1);
		if (err)
			return err;
	}
	return 0;
}

static struct rtc_class_ops rx8025_rtc_ops = {
	.read_time = rx8025_get_time,
	.set_time = rx8025_set_time,
	.read_alarm = rx8025_read_alarm,
	.set_alarm = rx8025_set_alarm,
	.alarm_irq_enable = rx8025_alarm_irq_enable,
};

/*
 * Clock precision adjustment support
 *
 * According to the RX8025 SA/NB application manual the frequency and
 * temperature characteristics can be approximated using the following
 * equation:
 *
 *   df = a * (ut - t)**2
 *
 *   df: Frequency deviation in any temperature
 *   a : Coefficient = (-35 +-5) * 10**-9
 *   ut: Ultimate temperature in degree = +25 +-5 degree
 *   t : Any temperature in degree
 *
 * Note that the clock adjustment in ppb must be entered (which is
 * the negative value of the deviation).
 */
static int rx8025_get_clock_adjust(struct device *dev, int *adj)
{
	struct i2c_client *client = to_i2c_client(dev);
	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, 0, "rx8025",
						client);
		if (err) {
			dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
			client->irq = 0;
		}
	}

	rx8025->rtc->max_user_freq = 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
	10	* <http://lists.lm-sensors.org/mailman/listinfo/lm-sensors>
	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);
fd9061fb	149	int status;
3c2b9075	150
fd9061fb AB	151	status = rx8025_read_reg(client, RX8025_REG_CTRL2);
fd9061fb AB	152	if (status < 0)
3c2b9075 WG	153	goto out;
	154
	155	if (!(status & RX8025_BIT_CTRL2_XST))
	156	dev_warn(&client->dev, "Oscillation stop was detected,"
	157	"you may have to readjust the clock\n");
	158
	159	if (status & RX8025_BIT_CTRL2_CTFG) {
	160	/* periodic */
	161	status &= ~RX8025_BIT_CTRL2_CTFG;
3c2b9075	162	rtc_update_irq(rx8025->rtc, 1, RTC_PF \| RTC_IRQF);
3c2b9075 WG	163	}
	164
	165	if (status & RX8025_BIT_CTRL2_DAFG) {
	166	/* alarm */
	167	status &= RX8025_BIT_CTRL2_DAFG;
	168	if (rx8025_write_reg(client, RX8025_REG_CTRL1,
	169	rx8025->ctrl1 & ~RX8025_BIT_CTRL1_DALE))
	170	goto out;
3c2b9075	171	rtc_update_irq(rx8025->rtc, 1, RTC_AF \| RTC_IRQF);
3c2b9075 WG	172	}
3c2b9075 WG	173
3c2b9075	174	out:
b6a57c95	175	return IRQ_HANDLED;
3c2b9075 WG	176	}
	177
	178	static int rx8025_get_time(struct device dev, struct rtc_time dt)
	179	{
	180	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
fd9061fb	181	u8 date[7];
efbbb4fd	182	int err;
6f0a8cfe	183
efbbb4fd AB	184	err = rx8025_check_validity(dev);
	185	if (err)
	186	return err;
6f0a8cfe	187
3c2b9075 WG	188	err = rx8025_read_regs(rx8025->client, RX8025_REG_SEC, 7, date);
	189	if (err)
	190	return err;
	191
	192	dev_dbg(dev, "%s: read 0x%02x 0x%02x "
	193	"0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n", __func__,
	194	date[0], date[1], date[2], date[3], date[4],
	195	date[5], date[6]);
	196
	197	dt->tm_sec = bcd2bin(date[RX8025_REG_SEC] & 0x7f);
	198	dt->tm_min = bcd2bin(date[RX8025_REG_MIN] & 0x7f);
	199	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	200	dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x3f);
	201	else
	202	dt->tm_hour = bcd2bin(date[RX8025_REG_HOUR] & 0x1f) % 12
	203	+ (date[RX8025_REG_HOUR] & 0x20 ? 12 : 0);
	204
	205	dt->tm_mday = bcd2bin(date[RX8025_REG_MDAY] & 0x3f);
	206	dt->tm_mon = bcd2bin(date[RX8025_REG_MONTH] & 0x1f) - 1;
32672c55	207	dt->tm_year = bcd2bin(date[RX8025_REG_YEAR]) + 100;
3c2b9075 WG	208
	209	dev_dbg(dev, "%s: date %ds %dm %dh %dmd %dm %dy\n", __func__,
	210	dt->tm_sec, dt->tm_min, dt->tm_hour,
	211	dt->tm_mday, dt->tm_mon, dt->tm_year);
	212
	213	return rtc_valid_tm(dt);
	214	}
	215
	216	static int rx8025_set_time(struct device dev, struct rtc_time dt)
	217	{
	218	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	219	u8 date[7];
8c4a4467	220	int ret;
3c2b9075	221
32672c55 AB	222	if ((dt->tm_year < 100) \|\| (dt->tm_year > 199))
32672c55 AB	223	return -EINVAL;
3c2b9075 WG	224
	225	/*
	226	* Here the read-only bits are written as "0". I'm not sure if that
	227	* is sound.
	228	*/
	229	date[RX8025_REG_SEC] = bin2bcd(dt->tm_sec);
	230	date[RX8025_REG_MIN] = bin2bcd(dt->tm_min);
	231	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	232	date[RX8025_REG_HOUR] = bin2bcd(dt->tm_hour);
	233	else
	234	date[RX8025_REG_HOUR] = (dt->tm_hour >= 12 ? 0x20 : 0)
	235	\| bin2bcd((dt->tm_hour + 11) % 12 + 1);
	236
	237	date[RX8025_REG_WDAY] = bin2bcd(dt->tm_wday);
	238	date[RX8025_REG_MDAY] = bin2bcd(dt->tm_mday);
	239	date[RX8025_REG_MONTH] = bin2bcd(dt->tm_mon + 1);
32672c55	240	date[RX8025_REG_YEAR] = bin2bcd(dt->tm_year - 100);
3c2b9075 WG	241
	242	dev_dbg(dev,
	243	"%s: write 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x 0x%02x\n",
	244	__func__,
	245	date[0], date[1], date[2], date[3], date[4], date[5], date[6]);
	246
8c4a4467 AB	247	ret = rx8025_write_regs(rx8025->client, RX8025_REG_SEC, 7, date);
	248	if (ret < 0)
	249	return ret;
	250
	251	return rx8025_reset_validity(rx8025->client);
3c2b9075 WG	252	}
3c2b9075 WG	253
6f0a8cfe	254	static int rx8025_init_client(struct i2c_client *client)
3c2b9075 WG	255	{
	256	struct rx8025_data *rx8025 = i2c_get_clientdata(client);
	257	u8 ctrl[2], ctrl2;
	258	int need_clear = 0;
	259	int err;
	260
	261	err = rx8025_read_regs(rx8025->client, RX8025_REG_CTRL1, 2, ctrl);
	262	if (err)
	263	goto out;
	264
	265	/* Keep test bit zero ! */
	266	rx8025->ctrl1 = ctrl[0] & ~RX8025_BIT_CTRL1_TEST;
	267
3c2b9075 WG	268	if (ctrl[1] & (RX8025_BIT_CTRL2_DAFG \| RX8025_BIT_CTRL2_WAFG)) {
	269	dev_warn(&client->dev, "Alarm was detected\n");
	270	need_clear = 1;
	271	}
	272
5c66e1e0	273	if (ctrl[1] & RX8025_BIT_CTRL2_CTFG)
3c2b9075 WG	274	need_clear = 1;
3c2b9075 WG	275
6f0a8cfe	276	if (need_clear) {
a27c7bf6	277	ctrl2 = ctrl[1];
8c4a4467	278	ctrl2 &= ~(RX8025_BIT_CTRL2_CTFG \| RX8025_BIT_CTRL2_WAFG \|
3c2b9075	279	RX8025_BIT_CTRL2_DAFG);
3c2b9075 WG	280
	281	err = rx8025_write_reg(client, RX8025_REG_CTRL2, ctrl2);
	282	}
	283	out:
	284	return err;
	285	}
	286
	287	/* Alarm support */
	288	static int rx8025_read_alarm(struct device dev, struct rtc_wkalrm t)
	289	{
	290	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	291	struct i2c_client *client = rx8025->client;
fd9061fb AB	292	u8 ald[2];
fd9061fb AB	293	int ctrl2, err;
3c2b9075 WG	294
	295	if (client->irq <= 0)
	296	return -EINVAL;
	297
	298	err = rx8025_read_regs(client, RX8025_REG_ALDMIN, 2, ald);
	299	if (err)
	300	return err;
	301
fd9061fb AB	302	ctrl2 = rx8025_read_reg(client, RX8025_REG_CTRL2);
	303	if (ctrl2 < 0)
	304	return ctrl2;
3c2b9075 WG	305
	306	dev_dbg(dev, "%s: read alarm 0x%02x 0x%02x ctrl2 %02x\n",
	307	__func__, ald[0], ald[1], ctrl2);
	308
	309	/* Hardware alarms precision is 1 minute! */
	310	t->time.tm_sec = 0;
	311	t->time.tm_min = bcd2bin(ald[0] & 0x7f);
	312	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	313	t->time.tm_hour = bcd2bin(ald[1] & 0x3f);
	314	else
	315	t->time.tm_hour = bcd2bin(ald[1] & 0x1f) % 12
	316	+ (ald[1] & 0x20 ? 12 : 0);
	317
	318	t->time.tm_wday = -1;
	319	t->time.tm_mday = -1;
	320	t->time.tm_mon = -1;
	321	t->time.tm_year = -1;
	322
	323	dev_dbg(dev, "%s: date: %ds %dm %dh %dmd %dm %dy\n",
	324	__func__,
	325	t->time.tm_sec, t->time.tm_min, t->time.tm_hour,
	326	t->time.tm_mday, t->time.tm_mon, t->time.tm_year);
	327	t->enabled = !!(rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE);
	328	t->pending = (ctrl2 & RX8025_BIT_CTRL2_DAFG) && t->enabled;
	329
	330	return err;
	331	}
	332
	333	static int rx8025_set_alarm(struct device dev, struct rtc_wkalrm t)
	334	{
	335	struct i2c_client *client = to_i2c_client(dev);
	336	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
	337	u8 ald[2];
	338	int err;
	339
	340	if (client->irq <= 0)
	341	return -EINVAL;
	342
	343	/* Hardware alarm precision is 1 minute! */
	344	ald[0] = bin2bcd(t->time.tm_min);
	345	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_1224)
	346	ald[1] = bin2bcd(t->time.tm_hour);
	347	else
	348	ald[1] = (t->time.tm_hour >= 12 ? 0x20 : 0)
	349	\| bin2bcd((t->time.tm_hour + 11) % 12 + 1);
	350
	351	dev_dbg(dev, "%s: write 0x%02x 0x%02x\n", __func__, ald[0], ald[1]);
	352
	353	if (rx8025->ctrl1 & RX8025_BIT_CTRL1_DALE) {
	354	rx8025->ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
	355	err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
	356	rx8025->ctrl1);
	357	if (err)
	358	return err;
	359	}
	360	err = rx8025_write_regs(rx8025->client, RX8025_REG_ALDMIN, 2, ald);
	361	if (err)
	362	return err;
	363
	364	if (t->enabled) {
	365	rx8025->ctrl1 \|= RX8025_BIT_CTRL1_DALE;
	366	err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
	367	rx8025->ctrl1);
	368	if (err)
369	return err;
370	}
371
372	return 0;
373	}
374
375	static int rx8025_alarm_irq_enable(struct device *dev, unsigned int enabled)
376	{
377	struct rx8025_data *rx8025 = dev_get_drvdata(dev);
378	u8 ctrl1;
379	int err;
380
381	ctrl1 = rx8025->ctrl1;
382	if (enabled)
383	ctrl1 \|= RX8025_BIT_CTRL1_DALE;
384	else
385	ctrl1 &= ~RX8025_BIT_CTRL1_DALE;
386
387	if (ctrl1 != rx8025->ctrl1) {
388	rx8025->ctrl1 = ctrl1;
389	err = rx8025_write_reg(rx8025->client, RX8025_REG_CTRL1,
390	rx8025->ctrl1);
391	if (err)
392	return err;
393	}
394	return 0;
395	}
396
3c2b9075 WG	397	static struct rtc_class_ops rx8025_rtc_ops = {
	398	.read_time = rx8025_get_time,
	399	.set_time = rx8025_set_time,
	400	.read_alarm = rx8025_read_alarm,
	401	.set_alarm = rx8025_set_alarm,
	402	.alarm_irq_enable = rx8025_alarm_irq_enable,
3c2b9075 WG	403	};
	404
	405	/*
	406	* Clock precision adjustment support
	407	*
	408	* According to the RX8025 SA/NB application manual the frequency and
b770ffd4	409	* temperature characteristics can be approximated using the following
3c2b9075 WG	410	* equation:
	411	*
	412	* df = a * (ut - t)**2
	413	*
	414	* df: Frequency deviation in any temperature
	415	* a : Coefficient = (-35 +-5) * 10**-9
	416	* ut: Ultimate temperature in degree = +25 +-5 degree
	417	* t : Any temperature in degree
	418	*
	419	* Note that the clock adjustment in ppb must be entered (which is
	420	* the negative value of the deviation).
	421	*/
	422	static int rx8025_get_clock_adjust(struct device dev, int adj)
	423	{
	424	struct i2c_client *client = to_i2c_client(dev);
fd9061fb	425	int digoff;
3c2b9075	426
fd9061fb AB	427	digoff = rx8025_read_reg(client, RX8025_REG_DIGOFF);
	428	if (digoff < 0)
	429	return digoff;
3c2b9075 WG	430
	431	*adj = digoff >= 64 ? digoff - 128 : digoff;
	432	if (*adj > 0)
	433	(*adj)--;
	434	adj = -RX8025_ADJ_RESOLUTION;
	435
	436	return 0;
	437	}
	438
	439	static int rx8025_set_clock_adjust(struct device *dev, int adj)
	440	{
	441	struct i2c_client *client = to_i2c_client(dev);
	442	u8 digoff;
	443	int err;
	444
	445	adj /= -RX8025_ADJ_RESOLUTION;
	446	if (adj > RX8025_ADJ_DATA_MAX)
	447	adj = RX8025_ADJ_DATA_MAX;
	448	else if (adj < RX8025_ADJ_DATA_MIN)
	449	adj = RX8025_ADJ_DATA_MIN;
	450	else if (adj > 0)
	451	adj++;
	452	else if (adj < 0)
	453	adj += 128;
	454	digoff = adj;
	455
	456	err = rx8025_write_reg(client, RX8025_REG_DIGOFF, digoff);
	457	if (err)
	458	return err;
	459
	460	dev_dbg(dev, "%s: write 0x%02x\n", __func__, digoff);
	461
	462	return 0;
	463	}
	464
	465	static ssize_t rx8025_sysfs_show_clock_adjust(struct device *dev,
	466	struct device_attribute *attr,
	467	char *buf)
	468	{
	469	int err, adj;
	470
	471	err = rx8025_get_clock_adjust(dev, &adj);
	472	if (err)
	473	return err;
	474
	475	return sprintf(buf, "%d\n", adj);
	476	}
	477
	478	static ssize_t rx8025_sysfs_store_clock_adjust(struct device *dev,
	479	struct device_attribute *attr,
	480	const char *buf, size_t count)
	481	{
	482	int adj, err;
	483
	484	if (sscanf(buf, "%i", &adj) != 1)
	485	return -EINVAL;
	486
	487	err = rx8025_set_clock_adjust(dev, adj);
	488
	489	return err ? err : count;
	490	}
	491
	492	static DEVICE_ATTR(clock_adjust_ppb, S_IRUGO \| S_IWUSR,
	493	rx8025_sysfs_show_clock_adjust,
494	rx8025_sysfs_store_clock_adjust);
495
496	static int rx8025_sysfs_register(struct device *dev)
497	{
498	return device_create_file(dev, &dev_attr_clock_adjust_ppb);
499	}
500
501	static void rx8025_sysfs_unregister(struct device *dev)
502	{
503	device_remove_file(dev, &dev_attr_clock_adjust_ppb);
504	}
505
5a167f45 GKH	506	static int rx8025_probe(struct i2c_client *client,
5a167f45 GKH	507	const struct i2c_device_id *id)
3c2b9075 WG	508	{
	509	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
	510	struct rx8025_data *rx8025;
6f0a8cfe	511	int err = 0;
3c2b9075 WG	512
	513	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
	514	\| I2C_FUNC_SMBUS_I2C_BLOCK)) {
	515	dev_err(&adapter->dev,
	516	"doesn't support required functionality\n");
dbcce7cf	517	return -EIO;
3c2b9075 WG	518	}
3c2b9075 WG	519
fac42b41	520	rx8025 = devm_kzalloc(&client->dev, sizeof(*rx8025), GFP_KERNEL);
3c2b9075	521	if (!rx8025) {
dbcce7cf	522	return -ENOMEM;
3c2b9075 WG	523	}
	524
	525	rx8025->client = client;
	526	i2c_set_clientdata(client, rx8025);
3c2b9075	527
6f0a8cfe	528	err = rx8025_init_client(client);
3c2b9075	529	if (err)
dbcce7cf	530	return err;
3c2b9075	531
fac42b41	532	rx8025->rtc = devm_rtc_device_register(&client->dev, client->name,
3c2b9075 WG	533	&rx8025_rtc_ops, THIS_MODULE);
3c2b9075 WG	534	if (IS_ERR(rx8025->rtc)) {
3c2b9075	535	dev_err(&client->dev, "unable to register the class device\n");
dbcce7cf	536	return PTR_ERR(rx8025->rtc);
3c2b9075 WG	537	}
	538
	539	if (client->irq > 0) {
	540	dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
f0b63a1d AB	541	err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
	542	rx8025_handle_irq, 0, "rx8025",
	543	client);
3c2b9075	544	if (err) {
8a06513d AB	545	dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
8a06513d AB	546	client->irq = 0;
3c2b9075 WG	547	}
	548	}
	549
3c2b9075 WG	550	rx8025->rtc->max_user_freq = 1;
	551
	552	err = rx8025_sysfs_register(&client->dev);
3c2b9075 WG	553	return err;
	554	}
	555
5a167f45	556	static int rx8025_remove(struct i2c_client *client)
3c2b9075	557	{
3c2b9075	558	rx8025_sysfs_unregister(&client->dev);
3c2b9075 WG	559	return 0;
	560	}
	561
	562	static struct i2c_driver rx8025_driver = {
	563	.driver = {
	564	.name = "rtc-rx8025",
3c2b9075 WG	565	},
3c2b9075 WG	566	.probe = rx8025_probe,
5a167f45	567	.remove = rx8025_remove,
3c2b9075 WG	568	.id_table = rx8025_id,
	569	};
	570
0abc9201	571	module_i2c_driver(rx8025_driver);
3c2b9075 WG	572
	573	MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
	574	MODULE_DESCRIPTION("RX-8025 SA/NB RTC driver");
	575	MODULE_LICENSE("GPL");