[linux-2.6-block.git] / drivers / rtc / rtc-abx80x.c

/*
 * A driver for the I2C members of the Abracon AB x8xx RTC family,
 * and compatible: AB 1805 and AB 0805
 *
 * Copyright 2014-2015 Macq S.A.
 *
 * Author: Philippe De Muyter <phdm@macqel.be>
 * Author: Alexandre Belloni <alexandre.belloni@free-electrons.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/i2c.h>
#include <linux/module.h>
#include <linux/rtc.h>

#define ABX8XX_REG_HTH		0x00
#define ABX8XX_REG_SC		0x01
#define ABX8XX_REG_MN		0x02
#define ABX8XX_REG_HR		0x03
#define ABX8XX_REG_DA		0x04
#define ABX8XX_REG_MO		0x05
#define ABX8XX_REG_YR		0x06
#define ABX8XX_REG_WD		0x07

#define ABX8XX_REG_AHTH		0x08
#define ABX8XX_REG_ASC		0x09
#define ABX8XX_REG_AMN		0x0a
#define ABX8XX_REG_AHR		0x0b
#define ABX8XX_REG_ADA		0x0c
#define ABX8XX_REG_AMO		0x0d
#define ABX8XX_REG_AWD		0x0e

#define ABX8XX_REG_STATUS	0x0f
#define ABX8XX_STATUS_AF	BIT(2)

#define ABX8XX_REG_CTRL1	0x10
#define ABX8XX_CTRL_WRITE	BIT(0)
#define ABX8XX_CTRL_ARST	BIT(2)
#define ABX8XX_CTRL_12_24	BIT(6)

#define ABX8XX_REG_IRQ		0x12
#define ABX8XX_IRQ_AIE		BIT(2)
#define ABX8XX_IRQ_IM_1_4	(0x3 << 5)

#define ABX8XX_REG_CD_TIMER_CTL	0x18

#define ABX8XX_REG_OSC		0x1c
#define ABX8XX_OSC_FOS		BIT(3)
#define ABX8XX_OSC_BOS		BIT(4)
#define ABX8XX_OSC_ACAL_512	BIT(5)
#define ABX8XX_OSC_ACAL_1024	BIT(6)

#define ABX8XX_OSC_OSEL		BIT(7)

#define ABX8XX_REG_OSS		0x1d
#define ABX8XX_OSS_OMODE	BIT(4)

#define ABX8XX_REG_CFG_KEY	0x1f
#define ABX8XX_CFG_KEY_OSC	0xa1
#define ABX8XX_CFG_KEY_MISC	0x9d

#define ABX8XX_REG_ID0		0x28

#define ABX8XX_REG_TRICKLE	0x20
#define ABX8XX_TRICKLE_CHARGE_ENABLE	0xa0
#define ABX8XX_TRICKLE_STANDARD_DIODE	0x8
#define ABX8XX_TRICKLE_SCHOTTKY_DIODE	0x4

static u8 trickle_resistors[] = {0, 3, 6, 11};

enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
	AB1801, AB1803, AB1804, AB1805, ABX80X};

struct abx80x_cap {
	u16 pn;
	bool has_tc;
};

static struct abx80x_cap abx80x_caps[] = {
	[AB0801] = {.pn = 0x0801},
	[AB0803] = {.pn = 0x0803},
	[AB0804] = {.pn = 0x0804, .has_tc = true},
	[AB0805] = {.pn = 0x0805, .has_tc = true},
	[AB1801] = {.pn = 0x1801},
	[AB1803] = {.pn = 0x1803},
	[AB1804] = {.pn = 0x1804, .has_tc = true},
	[AB1805] = {.pn = 0x1805, .has_tc = true},
	[ABX80X] = {.pn = 0}
};

static int abx80x_is_rc_mode(struct i2c_client *client)
{
	int flags = 0;

	flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
	if (flags < 0) {
		dev_err(&client->dev,
			"Failed to read autocalibration attribute\n");
		return flags;
	}

	return (flags & ABX8XX_OSS_OMODE) ? 1 : 0;
}

static int abx80x_enable_trickle_charger(struct i2c_client *client,
					 u8 trickle_cfg)
{
	int err;

	/*
	 * Write the configuration key register to enable access to the Trickle
	 * register
	 */
	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
					ABX8XX_CFG_KEY_MISC);
	if (err < 0) {
		dev_err(&client->dev, "Unable to write configuration key\n");
		return -EIO;
	}

	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
					ABX8XX_TRICKLE_CHARGE_ENABLE |
					trickle_cfg);
	if (err < 0) {
		dev_err(&client->dev, "Unable to write trickle register\n");
		return -EIO;
	}

	return 0;
}

static int abx80x_rtc_read_time(struct device *dev, struct rtc_time *tm)
{
	struct i2c_client *client = to_i2c_client(dev);
	unsigned char buf[8];
	int err;

	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
					    sizeof(buf), buf);
	if (err < 0) {
		dev_err(&client->dev, "Unable to read date\n");
		return -EIO;
	}

	tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
	tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
	tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
	tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
	tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
	tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1;
	tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100;

	err = rtc_valid_tm(tm);
	if (err < 0)
		dev_err(&client->dev, "retrieved date/time is not valid.\n");

	return err;
}

static int abx80x_rtc_set_time(struct device *dev, struct rtc_time *tm)
{
	struct i2c_client *client = to_i2c_client(dev);
	unsigned char buf[8];
	int err;

	if (tm->tm_year < 100)
		return -EINVAL;

	buf[ABX8XX_REG_HTH] = 0;
	buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
	buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
	buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
	buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
	buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
	buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
	buf[ABX8XX_REG_WD] = tm->tm_wday;

	err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
					     sizeof(buf), buf);
	if (err < 0) {
		dev_err(&client->dev, "Unable to write to date registers\n");
		return -EIO;
	}

	return 0;
}

static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
{
	struct i2c_client *client = dev_id;
	struct rtc_device *rtc = i2c_get_clientdata(client);
	int status;

	status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
	if (status < 0)
		return IRQ_NONE;

	if (status & ABX8XX_STATUS_AF)
		rtc_update_irq(rtc, 1, RTC_AF | RTC_IRQF);

	i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);

	return IRQ_HANDLED;
}

static int abx80x_read_alarm(struct device *dev, struct rtc_wkalrm *t)
{
	struct i2c_client *client = to_i2c_client(dev);
	unsigned char buf[7];

	int irq_mask, err;

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

	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
					    sizeof(buf), buf);
	if (err)
		return err;

	irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
	if (irq_mask < 0)
		return irq_mask;

	t->time.tm_sec = bcd2bin(buf[0] & 0x7F);
	t->time.tm_min = bcd2bin(buf[1] & 0x7F);
	t->time.tm_hour = bcd2bin(buf[2] & 0x3F);
	t->time.tm_mday = bcd2bin(buf[3] & 0x3F);
	t->time.tm_mon = bcd2bin(buf[4] & 0x1F) - 1;
	t->time.tm_wday = buf[5] & 0x7;

	t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE);
	t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled;

	return err;
}

static int abx80x_set_alarm(struct device *dev, struct rtc_wkalrm *t)
{
	struct i2c_client *client = to_i2c_client(dev);
	u8 alarm[6];
	int err;

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

	alarm[0] = 0x0;
	alarm[1] = bin2bcd(t->time.tm_sec);
	alarm[2] = bin2bcd(t->time.tm_min);
	alarm[3] = bin2bcd(t->time.tm_hour);
	alarm[4] = bin2bcd(t->time.tm_mday);
	alarm[5] = bin2bcd(t->time.tm_mon + 1);

	err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH,
					     sizeof(alarm), alarm);
	if (err < 0) {
		dev_err(&client->dev, "Unable to write alarm registers\n");
		return -EIO;
	}

	if (t->enabled) {
		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
						(ABX8XX_IRQ_IM_1_4 |
						 ABX8XX_IRQ_AIE));
		if (err)
			return err;
	}

	return 0;
}

static int abx80x_rtc_set_autocalibration(struct device *dev,
					  int autocalibration)
{
	struct i2c_client *client = to_i2c_client(dev);
	int retval, flags = 0;

	if ((autocalibration != 0) && (autocalibration != 1024) &&
	    (autocalibration != 512)) {
		dev_err(dev, "autocalibration value outside permitted range\n");
		return -EINVAL;
	}

	flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
	if (flags < 0)
		return flags;

	if (autocalibration == 0) {
		flags &= ~(ABX8XX_OSC_ACAL_512 | ABX8XX_OSC_ACAL_1024);
	} else if (autocalibration == 1024) {
		/* 1024 autocalibration is 0x10 */
		flags |= ABX8XX_OSC_ACAL_1024;
		flags &= ~(ABX8XX_OSC_ACAL_512);
	} else {
		/* 512 autocalibration is 0x11 */
		flags |= (ABX8XX_OSC_ACAL_1024 | ABX8XX_OSC_ACAL_512);
	}

	/* Unlock write access to Oscillator Control Register */
	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
					   ABX8XX_CFG_KEY_OSC);
	if (retval < 0) {
		dev_err(dev, "Failed to write CONFIG_KEY register\n");
		return retval;
	}

	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);

	return retval;
}

static int abx80x_rtc_get_autocalibration(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	int flags = 0, autocalibration;

	flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
	if (flags < 0)
		return flags;

	if (flags & ABX8XX_OSC_ACAL_512)
		autocalibration = 512;
	else if (flags & ABX8XX_OSC_ACAL_1024)
		autocalibration = 1024;
	else
		autocalibration = 0;

	return autocalibration;
}

static ssize_t autocalibration_store(struct device *dev,
				     struct device_attribute *attr,
				     const char *buf, size_t count)
{
	int retval;
	unsigned long autocalibration = 0;

	retval = kstrtoul(buf, 10, &autocalibration);
	if (retval < 0) {
		dev_err(dev, "Failed to store RTC autocalibration attribute\n");
		return -EINVAL;
	}

	retval = abx80x_rtc_set_autocalibration(dev, autocalibration);

	return retval ? retval : count;
}

static ssize_t autocalibration_show(struct device *dev,
				    struct device_attribute *attr, char *buf)
{
	int autocalibration = 0;

	autocalibration = abx80x_rtc_get_autocalibration(dev);
	if (autocalibration < 0) {
		dev_err(dev, "Failed to read RTC autocalibration\n");
		sprintf(buf, "0\n");
		return autocalibration;
	}

	return sprintf(buf, "%d\n", autocalibration);
}

static DEVICE_ATTR_RW(autocalibration);

static ssize_t oscillator_store(struct device *dev,
				struct device_attribute *attr,
				const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	int retval, flags, rc_mode = 0;

	if (strncmp(buf, "rc", 2) == 0) {
		rc_mode = 1;
	} else if (strncmp(buf, "xtal", 4) == 0) {
		rc_mode = 0;
	} else {
		dev_err(dev, "Oscillator selection value outside permitted ones\n");
		return -EINVAL;
	}

	flags =  i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
	if (flags < 0)
		return flags;

	if (rc_mode == 0)
		flags &= ~(ABX8XX_OSC_OSEL);
	else
		flags |= (ABX8XX_OSC_OSEL);

	/* Unlock write access on Oscillator Control register */
	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
					   ABX8XX_CFG_KEY_OSC);
	if (retval < 0) {
		dev_err(dev, "Failed to write CONFIG_KEY register\n");
		return retval;
	}

	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
	if (retval < 0) {
		dev_err(dev, "Failed to write Oscillator Control register\n");
		return retval;
	}

	return retval ? retval : count;
}

static ssize_t oscillator_show(struct device *dev,
			       struct device_attribute *attr, char *buf)
{
	int rc_mode = 0;
	struct i2c_client *client = to_i2c_client(dev);

	rc_mode = abx80x_is_rc_mode(client);

	if (rc_mode < 0) {
		dev_err(dev, "Failed to read RTC oscillator selection\n");
		sprintf(buf, "\n");
		return rc_mode;
	}

	if (rc_mode)
		return sprintf(buf, "rc\n");
	else
		return sprintf(buf, "xtal\n");
}

static DEVICE_ATTR_RW(oscillator);

static struct attribute *rtc_calib_attrs[] = {
	&dev_attr_autocalibration.attr,
	&dev_attr_oscillator.attr,
	NULL,
};

static const struct attribute_group rtc_calib_attr_group = {
	.attrs		= rtc_calib_attrs,
};

static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
	struct i2c_client *client = to_i2c_client(dev);
	int err;

	if (enabled)
		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
						(ABX8XX_IRQ_IM_1_4 |
						 ABX8XX_IRQ_AIE));
	else
		err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
						ABX8XX_IRQ_IM_1_4);
	return err;
}

static const struct rtc_class_ops abx80x_rtc_ops = {
	.read_time	= abx80x_rtc_read_time,
	.set_time	= abx80x_rtc_set_time,
	.read_alarm	= abx80x_read_alarm,
	.set_alarm	= abx80x_set_alarm,
	.alarm_irq_enable = abx80x_alarm_irq_enable,
};

static int abx80x_dt_trickle_cfg(struct device_node *np)
{
	const char *diode;
	int trickle_cfg = 0;
	int i, ret;
	u32 tmp;

	ret = of_property_read_string(np, "abracon,tc-diode", &diode);
	if (ret)
		return ret;

	if (!strcmp(diode, "standard"))
		trickle_cfg |= ABX8XX_TRICKLE_STANDARD_DIODE;
	else if (!strcmp(diode, "schottky"))
		trickle_cfg |= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
	else
		return -EINVAL;

	ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
	if (ret)
		return ret;

	for (i = 0; i < sizeof(trickle_resistors); i++)
		if (trickle_resistors[i] == tmp)
			break;

	if (i == sizeof(trickle_resistors))
		return -EINVAL;

	return (trickle_cfg | i);
}

static void rtc_calib_remove_sysfs_group(void *_dev)
{
	struct device *dev = _dev;

	sysfs_remove_group(&dev->kobj, &rtc_calib_attr_group);
}

static int abx80x_probe(struct i2c_client *client,
			const struct i2c_device_id *id)
{
	struct device_node *np = client->dev.of_node;
	struct rtc_device *rtc;
	int i, data, err, trickle_cfg = -EINVAL;
	char buf[7];
	unsigned int part = id->driver_data;
	unsigned int partnumber;
	unsigned int majrev, minrev;
	unsigned int lot;
	unsigned int wafer;
	unsigned int uid;

	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
		return -ENODEV;

	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
					    sizeof(buf), buf);
	if (err < 0) {
		dev_err(&client->dev, "Unable to read partnumber\n");
		return -EIO;
	}

	partnumber = (buf[0] << 8) | buf[1];
	majrev = buf[2] >> 3;
	minrev = buf[2] & 0x7;
	lot = ((buf[4] & 0x80) << 2) | ((buf[6] & 0x80) << 1) | buf[3];
	uid = ((buf[4] & 0x7f) << 8) | buf[5];
	wafer = (buf[6] & 0x7c) >> 2;
	dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
		 partnumber, majrev, minrev, lot, wafer, uid);

	data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
	if (data < 0) {
		dev_err(&client->dev, "Unable to read control register\n");
		return -EIO;
	}

	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
					((data & ~(ABX8XX_CTRL_12_24 |
						   ABX8XX_CTRL_ARST)) |
					 ABX8XX_CTRL_WRITE));
	if (err < 0) {
		dev_err(&client->dev, "Unable to write control register\n");
		return -EIO;
	}

	/* part autodetection */
	if (part == ABX80X) {
		for (i = 0; abx80x_caps[i].pn; i++)
			if (partnumber == abx80x_caps[i].pn)
				break;
		if (abx80x_caps[i].pn == 0) {
			dev_err(&client->dev, "Unknown part: %04x\n",
				partnumber);
			return -EINVAL;
		}
		part = i;
	}

	if (partnumber != abx80x_caps[part].pn) {
		dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
			partnumber, abx80x_caps[part].pn);
		return -EINVAL;
	}

	if (np && abx80x_caps[part].has_tc)
		trickle_cfg = abx80x_dt_trickle_cfg(np);

	if (trickle_cfg > 0) {
		dev_info(&client->dev, "Enabling trickle charger: %02x\n",
			 trickle_cfg);
		abx80x_enable_trickle_charger(client, trickle_cfg);
	}

	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL,
					BIT(2));
	if (err)
		return err;

	rtc = devm_rtc_device_register(&client->dev, "abx8xx",
				       &abx80x_rtc_ops, THIS_MODULE);

	if (IS_ERR(rtc))
		return PTR_ERR(rtc);

	i2c_set_clientdata(client, 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,
						abx80x_handle_irq,
						IRQF_SHARED | IRQF_ONESHOT,
						"abx8xx",
						client);
		if (err) {
			dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
			client->irq = 0;
		}
	}

	/* Export sysfs entries */
	err = sysfs_create_group(&(&client->dev)->kobj, &rtc_calib_attr_group);
	if (err) {
		dev_err(&client->dev, "Failed to create sysfs group: %d\n",
			err);
		return err;
	}

	err = devm_add_action(&client->dev, rtc_calib_remove_sysfs_group,
			      &client->dev);
	if (err) {
		rtc_calib_remove_sysfs_group(&client->dev);
		dev_err(&client->dev,
			"Failed to add sysfs cleanup action: %d\n",
			err);
		return err;
	}

	return 0;
}

static int abx80x_remove(struct i2c_client *client)
{
	return 0;
}

static const struct i2c_device_id abx80x_id[] = {
	{ "abx80x", ABX80X },
	{ "ab0801", AB0801 },
	{ "ab0803", AB0803 },
	{ "ab0804", AB0804 },
	{ "ab0805", AB0805 },
	{ "ab1801", AB1801 },
	{ "ab1803", AB1803 },
	{ "ab1804", AB1804 },
	{ "ab1805", AB1805 },
	{ "rv1805", AB1805 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, abx80x_id);

static struct i2c_driver abx80x_driver = {
	.driver		= {
		.name	= "rtc-abx80x",
	},
	.probe		= abx80x_probe,
	.remove		= abx80x_remove,
	.id_table	= abx80x_id,
};

module_i2c_driver(abx80x_driver);

MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
4d61ff6b PDM	1	/*
	2	* A driver for the I2C members of the Abracon AB x8xx RTC family,
	3	* and compatible: AB 1805 and AB 0805
	4	*
	5	* Copyright 2014-2015 Macq S.A.
	6	*
	7	* Author: Philippe De Muyter <phdm@macqel.be>
	8	* Author: Alexandre Belloni <alexandre.belloni@free-electrons.com>
	9	*
	10	* This program is free software; you can redistribute it and/or modify
	11	* it under the terms of the GNU General Public License version 2 as
	12	* published by the Free Software Foundation.
	13	*
	14	*/
	15
	16	#include <linux/bcd.h>
	17	#include <linux/i2c.h>
	18	#include <linux/module.h>
	19	#include <linux/rtc.h>
	20
	21	#define ABX8XX_REG_HTH 0x00
	22	#define ABX8XX_REG_SC 0x01
	23	#define ABX8XX_REG_MN 0x02
	24	#define ABX8XX_REG_HR 0x03
	25	#define ABX8XX_REG_DA 0x04
	26	#define ABX8XX_REG_MO 0x05
	27	#define ABX8XX_REG_YR 0x06
	28	#define ABX8XX_REG_WD 0x07
	29
718a820a AB	30	#define ABX8XX_REG_AHTH 0x08
	31	#define ABX8XX_REG_ASC 0x09
	32	#define ABX8XX_REG_AMN 0x0a
	33	#define ABX8XX_REG_AHR 0x0b
	34	#define ABX8XX_REG_ADA 0x0c
	35	#define ABX8XX_REG_AMO 0x0d
	36	#define ABX8XX_REG_AWD 0x0e
	37
	38	#define ABX8XX_REG_STATUS 0x0f
	39	#define ABX8XX_STATUS_AF BIT(2)
	40
4d61ff6b	41	#define ABX8XX_REG_CTRL1 0x10
5f1b2f77	42	#define ABX8XX_CTRL_WRITE BIT(0)
718a820a	43	#define ABX8XX_CTRL_ARST BIT(2)
4d61ff6b PDM	44	#define ABX8XX_CTRL_12_24 BIT(6)
4d61ff6b PDM	45
718a820a AB	46	#define ABX8XX_REG_IRQ 0x12
	47	#define ABX8XX_IRQ_AIE BIT(2)
	48	#define ABX8XX_IRQ_IM_1_4 (0x3 << 5)
	49
	50	#define ABX8XX_REG_CD_TIMER_CTL 0x18
	51
59a8383a MJ	52	#define ABX8XX_REG_OSC 0x1c
	53	#define ABX8XX_OSC_FOS BIT(3)
	54	#define ABX8XX_OSC_BOS BIT(4)
	55	#define ABX8XX_OSC_ACAL_512 BIT(5)
	56	#define ABX8XX_OSC_ACAL_1024 BIT(6)
	57
	58	#define ABX8XX_OSC_OSEL BIT(7)
	59
	60	#define ABX8XX_REG_OSS 0x1d
	61	#define ABX8XX_OSS_OMODE BIT(4)
	62
4d61ff6b	63	#define ABX8XX_REG_CFG_KEY 0x1f
59a8383a	64	#define ABX8XX_CFG_KEY_OSC 0xa1
4d61ff6b PDM	65	#define ABX8XX_CFG_KEY_MISC 0x9d
	66
	67	#define ABX8XX_REG_ID0 0x28
	68
	69	#define ABX8XX_REG_TRICKLE 0x20
	70	#define ABX8XX_TRICKLE_CHARGE_ENABLE 0xa0
	71	#define ABX8XX_TRICKLE_STANDARD_DIODE 0x8
	72	#define ABX8XX_TRICKLE_SCHOTTKY_DIODE 0x4
	73
	74	static u8 trickle_resistors[] = {0, 3, 6, 11};
	75
	76	enum abx80x_chip {AB0801, AB0803, AB0804, AB0805,
	77	AB1801, AB1803, AB1804, AB1805, ABX80X};
	78
	79	struct abx80x_cap {
	80	u16 pn;
	81	bool has_tc;
	82	};
	83
	84	static struct abx80x_cap abx80x_caps[] = {
	85	[AB0801] = {.pn = 0x0801},
	86	[AB0803] = {.pn = 0x0803},
	87	[AB0804] = {.pn = 0x0804, .has_tc = true},
	88	[AB0805] = {.pn = 0x0805, .has_tc = true},
	89	[AB1801] = {.pn = 0x1801},
	90	[AB1803] = {.pn = 0x1803},
	91	[AB1804] = {.pn = 0x1804, .has_tc = true},
	92	[AB1805] = {.pn = 0x1805, .has_tc = true},
	93	[ABX80X] = {.pn = 0}
	94	};
	95
59a8383a MJ	96	static int abx80x_is_rc_mode(struct i2c_client *client)
	97	{
	98	int flags = 0;
	99
	100	flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSS);
	101	if (flags < 0) {
	102	dev_err(&client->dev,
	103	"Failed to read autocalibration attribute\n");
	104	return flags;
	105	}
	106
	107	return (flags & ABX8XX_OSS_OMODE) ? 1 : 0;
	108	}
	109
4d61ff6b PDM	110	static int abx80x_enable_trickle_charger(struct i2c_client *client,
	111	u8 trickle_cfg)
	112	{
	113	int err;
	114
	115	/*
	116	* Write the configuration key register to enable access to the Trickle
	117	* register
	118	*/
	119	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
	120	ABX8XX_CFG_KEY_MISC);
	121	if (err < 0) {
	122	dev_err(&client->dev, "Unable to write configuration key\n");
	123	return -EIO;
	124	}
	125
	126	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_TRICKLE,
	127	ABX8XX_TRICKLE_CHARGE_ENABLE \|
	128	trickle_cfg);
	129	if (err < 0) {
	130	dev_err(&client->dev, "Unable to write trickle register\n");
	131	return -EIO;
	132	}
	133
	134	return 0;
	135	}
	136
	137	static int abx80x_rtc_read_time(struct device dev, struct rtc_time tm)
	138	{
	139	struct i2c_client *client = to_i2c_client(dev);
	140	unsigned char buf[8];
	141	int err;
	142
	143	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_HTH,
	144	sizeof(buf), buf);
	145	if (err < 0) {
	146	dev_err(&client->dev, "Unable to read date\n");
	147	return -EIO;
	148	}
	149
	150	tm->tm_sec = bcd2bin(buf[ABX8XX_REG_SC] & 0x7F);
	151	tm->tm_min = bcd2bin(buf[ABX8XX_REG_MN] & 0x7F);
	152	tm->tm_hour = bcd2bin(buf[ABX8XX_REG_HR] & 0x3F);
	153	tm->tm_wday = buf[ABX8XX_REG_WD] & 0x7;
	154	tm->tm_mday = bcd2bin(buf[ABX8XX_REG_DA] & 0x3F);
	155	tm->tm_mon = bcd2bin(buf[ABX8XX_REG_MO] & 0x1F) - 1;
	156	tm->tm_year = bcd2bin(buf[ABX8XX_REG_YR]) + 100;
	157
	158	err = rtc_valid_tm(tm);
	159	if (err < 0)
	160	dev_err(&client->dev, "retrieved date/time is not valid.\n");
	161
	162	return err;
	163	}
	164
	165	static int abx80x_rtc_set_time(struct device dev, struct rtc_time tm)
	166	{
	167	struct i2c_client *client = to_i2c_client(dev);
	168	unsigned char buf[8];
	169	int err;
	170
	171	if (tm->tm_year < 100)
	172	return -EINVAL;
	173
174	buf[ABX8XX_REG_HTH] = 0;
175	buf[ABX8XX_REG_SC] = bin2bcd(tm->tm_sec);
176	buf[ABX8XX_REG_MN] = bin2bcd(tm->tm_min);
177	buf[ABX8XX_REG_HR] = bin2bcd(tm->tm_hour);
178	buf[ABX8XX_REG_DA] = bin2bcd(tm->tm_mday);
179	buf[ABX8XX_REG_MO] = bin2bcd(tm->tm_mon + 1);
180	buf[ABX8XX_REG_YR] = bin2bcd(tm->tm_year - 100);
181	buf[ABX8XX_REG_WD] = tm->tm_wday;
182
183	err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_HTH,
184	sizeof(buf), buf);
185	if (err < 0) {
186	dev_err(&client->dev, "Unable to write to date registers\n");
187	return -EIO;
188	}
189
190	return 0;
191	}
192
718a820a AB	193	static irqreturn_t abx80x_handle_irq(int irq, void *dev_id)
	194	{
	195	struct i2c_client *client = dev_id;
	196	struct rtc_device *rtc = i2c_get_clientdata(client);
	197	int status;
	198
	199	status = i2c_smbus_read_byte_data(client, ABX8XX_REG_STATUS);
	200	if (status < 0)
	201	return IRQ_NONE;
	202
	203	if (status & ABX8XX_STATUS_AF)
	204	rtc_update_irq(rtc, 1, RTC_AF \| RTC_IRQF);
	205
	206	i2c_smbus_write_byte_data(client, ABX8XX_REG_STATUS, 0);
	207
	208	return IRQ_HANDLED;
	209	}
	210
	211	static int abx80x_read_alarm(struct device dev, struct rtc_wkalrm t)
	212	{
	213	struct i2c_client *client = to_i2c_client(dev);
	214	unsigned char buf[7];
	215
	216	int irq_mask, err;
	217
	218	if (client->irq <= 0)
	219	return -EINVAL;
	220
	221	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ASC,
	222	sizeof(buf), buf);
	223	if (err)
	224	return err;
	225
	226	irq_mask = i2c_smbus_read_byte_data(client, ABX8XX_REG_IRQ);
	227	if (irq_mask < 0)
	228	return irq_mask;
	229
	230	t->time.tm_sec = bcd2bin(buf[0] & 0x7F);
	231	t->time.tm_min = bcd2bin(buf[1] & 0x7F);
	232	t->time.tm_hour = bcd2bin(buf[2] & 0x3F);
	233	t->time.tm_mday = bcd2bin(buf[3] & 0x3F);
	234	t->time.tm_mon = bcd2bin(buf[4] & 0x1F) - 1;
	235	t->time.tm_wday = buf[5] & 0x7;
	236
	237	t->enabled = !!(irq_mask & ABX8XX_IRQ_AIE);
	238	t->pending = (buf[6] & ABX8XX_STATUS_AF) && t->enabled;
	239
	240	return err;
	241	}
	242
	243	static int abx80x_set_alarm(struct device dev, struct rtc_wkalrm t)
	244	{
	245	struct i2c_client *client = to_i2c_client(dev);
	246	u8 alarm[6];
	247	int err;
	248
	249	if (client->irq <= 0)
	250	return -EINVAL;
	251
	252	alarm[0] = 0x0;
	253	alarm[1] = bin2bcd(t->time.tm_sec);
	254	alarm[2] = bin2bcd(t->time.tm_min);
	255	alarm[3] = bin2bcd(t->time.tm_hour);
	256	alarm[4] = bin2bcd(t->time.tm_mday);
257	alarm[5] = bin2bcd(t->time.tm_mon + 1);
258
259	err = i2c_smbus_write_i2c_block_data(client, ABX8XX_REG_AHTH,
260	sizeof(alarm), alarm);
261	if (err < 0) {
262	dev_err(&client->dev, "Unable to write alarm registers\n");
263	return -EIO;
264	}
265
266	if (t->enabled) {
267	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
268	(ABX8XX_IRQ_IM_1_4 \|
269	ABX8XX_IRQ_AIE));
270	if (err)
271	return err;
272	}
273
274	return 0;
275	}
276
59a8383a MJ	277	static int abx80x_rtc_set_autocalibration(struct device *dev,
	278	int autocalibration)
	279	{
	280	struct i2c_client *client = to_i2c_client(dev);
	281	int retval, flags = 0;
	282
	283	if ((autocalibration != 0) && (autocalibration != 1024) &&
	284	(autocalibration != 512)) {
	285	dev_err(dev, "autocalibration value outside permitted range\n");
	286	return -EINVAL;
	287	}
	288
	289	flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
	290	if (flags < 0)
	291	return flags;
	292
	293	if (autocalibration == 0) {
	294	flags &= ~(ABX8XX_OSC_ACAL_512 \| ABX8XX_OSC_ACAL_1024);
	295	} else if (autocalibration == 1024) {
	296	/* 1024 autocalibration is 0x10 */
	297	flags \|= ABX8XX_OSC_ACAL_1024;
	298	flags &= ~(ABX8XX_OSC_ACAL_512);
	299	} else {
	300	/* 512 autocalibration is 0x11 */
	301	flags \|= (ABX8XX_OSC_ACAL_1024 \| ABX8XX_OSC_ACAL_512);
	302	}
	303
	304	/* Unlock write access to Oscillator Control Register */
	305	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
	306	ABX8XX_CFG_KEY_OSC);
	307	if (retval < 0) {
	308	dev_err(dev, "Failed to write CONFIG_KEY register\n");
	309	return retval;
	310	}
	311
	312	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
	313
	314	return retval;
	315	}
	316
	317	static int abx80x_rtc_get_autocalibration(struct device *dev)
	318	{
	319	struct i2c_client *client = to_i2c_client(dev);
	320	int flags = 0, autocalibration;
	321
	322	flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
	323	if (flags < 0)
	324	return flags;
	325
	326	if (flags & ABX8XX_OSC_ACAL_512)
	327	autocalibration = 512;
	328	else if (flags & ABX8XX_OSC_ACAL_1024)
	329	autocalibration = 1024;
	330	else
	331	autocalibration = 0;
	332
	333	return autocalibration;
	334	}
	335
	336	static ssize_t autocalibration_store(struct device *dev,
	337	struct device_attribute *attr,
	338	const char *buf, size_t count)
	339	{
	340	int retval;
341	unsigned long autocalibration = 0;
342
343	retval = kstrtoul(buf, 10, &autocalibration);
344	if (retval < 0) {
345	dev_err(dev, "Failed to store RTC autocalibration attribute\n");
346	return -EINVAL;
347	}
348
349	retval = abx80x_rtc_set_autocalibration(dev, autocalibration);
350
351	return retval ? retval : count;
352	}
353
354	static ssize_t autocalibration_show(struct device *dev,
355	struct device_attribute attr, char buf)
356	{
357	int autocalibration = 0;
358
359	autocalibration = abx80x_rtc_get_autocalibration(dev);
360	if (autocalibration < 0) {
361	dev_err(dev, "Failed to read RTC autocalibration\n");
362	sprintf(buf, "0\n");
363	return autocalibration;
364	}
365
366	return sprintf(buf, "%d\n", autocalibration);
367	}
368
369	static DEVICE_ATTR_RW(autocalibration);
370
371	static ssize_t oscillator_store(struct device *dev,
372	struct device_attribute *attr,
373	const char *buf, size_t count)
374	{
375	struct i2c_client *client = to_i2c_client(dev);
376	int retval, flags, rc_mode = 0;
377
378	if (strncmp(buf, "rc", 2) == 0) {
379	rc_mode = 1;
380	} else if (strncmp(buf, "xtal", 4) == 0) {
381	rc_mode = 0;
382	} else {
383	dev_err(dev, "Oscillator selection value outside permitted ones\n");
384	return -EINVAL;
385	}
386
387	flags = i2c_smbus_read_byte_data(client, ABX8XX_REG_OSC);
388	if (flags < 0)
389	return flags;
390
391	if (rc_mode == 0)
392	flags &= ~(ABX8XX_OSC_OSEL);
393	else
394	flags \|= (ABX8XX_OSC_OSEL);
395
396	/* Unlock write access on Oscillator Control register */
397	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_CFG_KEY,
398	ABX8XX_CFG_KEY_OSC);
399	if (retval < 0) {
400	dev_err(dev, "Failed to write CONFIG_KEY register\n");
401	return retval;
402	}
403
404	retval = i2c_smbus_write_byte_data(client, ABX8XX_REG_OSC, flags);
405	if (retval < 0) {
406	dev_err(dev, "Failed to write Oscillator Control register\n");
407	return retval;
408	}
409
410	return retval ? retval : count;
411	}
412
413	static ssize_t oscillator_show(struct device *dev,
414	struct device_attribute attr, char buf)
415	{
416	int rc_mode = 0;
417	struct i2c_client *client = to_i2c_client(dev);
418
419	rc_mode = abx80x_is_rc_mode(client);
420
421	if (rc_mode < 0) {
422	dev_err(dev, "Failed to read RTC oscillator selection\n");
423	sprintf(buf, "\n");
424	return rc_mode;
425	}
426
427	if (rc_mode)
428	return sprintf(buf, "rc\n");
429	else
430	return sprintf(buf, "xtal\n");
431	}
432
433	static DEVICE_ATTR_RW(oscillator);
434
435	static struct attribute *rtc_calib_attrs[] = {
436	&dev_attr_autocalibration.attr,
437	&dev_attr_oscillator.attr,
438	NULL,
439	};
440
441	static const struct attribute_group rtc_calib_attr_group = {
442	.attrs = rtc_calib_attrs,
443	};
444
718a820a AB	445	static int abx80x_alarm_irq_enable(struct device *dev, unsigned int enabled)
	446	{
	447	struct i2c_client *client = to_i2c_client(dev);
	448	int err;
	449
	450	if (enabled)
	451	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
	452	(ABX8XX_IRQ_IM_1_4 \|
	453	ABX8XX_IRQ_AIE));
	454	else
	455	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_IRQ,
	456	ABX8XX_IRQ_IM_1_4);
	457	return err;
	458	}
	459
4d61ff6b PDM	460	static const struct rtc_class_ops abx80x_rtc_ops = {
	461	.read_time = abx80x_rtc_read_time,
	462	.set_time = abx80x_rtc_set_time,
718a820a AB	463	.read_alarm = abx80x_read_alarm,
	464	.set_alarm = abx80x_set_alarm,
	465	.alarm_irq_enable = abx80x_alarm_irq_enable,
4d61ff6b PDM	466	};
	467
	468	static int abx80x_dt_trickle_cfg(struct device_node *np)
	469	{
	470	const char *diode;
	471	int trickle_cfg = 0;
	472	int i, ret;
	473	u32 tmp;
	474
	475	ret = of_property_read_string(np, "abracon,tc-diode", &diode);
	476	if (ret)
	477	return ret;
	478
	479	if (!strcmp(diode, "standard"))
	480	trickle_cfg \|= ABX8XX_TRICKLE_STANDARD_DIODE;
	481	else if (!strcmp(diode, "schottky"))
	482	trickle_cfg \|= ABX8XX_TRICKLE_SCHOTTKY_DIODE;
	483	else
	484	return -EINVAL;
	485
	486	ret = of_property_read_u32(np, "abracon,tc-resistor", &tmp);
	487	if (ret)
	488	return ret;
	489
	490	for (i = 0; i < sizeof(trickle_resistors); i++)
	491	if (trickle_resistors[i] == tmp)
	492	break;
	493
	494	if (i == sizeof(trickle_resistors))
	495	return -EINVAL;
	496
	497	return (trickle_cfg \| i);
	498	}
	499
59a8383a MJ	500	static void rtc_calib_remove_sysfs_group(void *_dev)
	501	{
	502	struct device *dev = _dev;
	503
	504	sysfs_remove_group(&dev->kobj, &rtc_calib_attr_group);
	505	}
	506
4d61ff6b PDM	507	static int abx80x_probe(struct i2c_client *client,
	508	const struct i2c_device_id *id)
	509	{
	510	struct device_node *np = client->dev.of_node;
	511	struct rtc_device *rtc;
	512	int i, data, err, trickle_cfg = -EINVAL;
	513	char buf[7];
	514	unsigned int part = id->driver_data;
	515	unsigned int partnumber;
	516	unsigned int majrev, minrev;
	517	unsigned int lot;
	518	unsigned int wafer;
	519	unsigned int uid;
	520
	521	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))
	522	return -ENODEV;
	523
	524	err = i2c_smbus_read_i2c_block_data(client, ABX8XX_REG_ID0,
	525	sizeof(buf), buf);
	526	if (err < 0) {
	527	dev_err(&client->dev, "Unable to read partnumber\n");
	528	return -EIO;
	529	}
	530
	531	partnumber = (buf[0] << 8) \| buf[1];
	532	majrev = buf[2] >> 3;
	533	minrev = buf[2] & 0x7;
	534	lot = ((buf[4] & 0x80) << 2) \| ((buf[6] & 0x80) << 1) \| buf[3];
	535	uid = ((buf[4] & 0x7f) << 8) \| buf[5];
	536	wafer = (buf[6] & 0x7c) >> 2;
	537	dev_info(&client->dev, "model %04x, revision %u.%u, lot %x, wafer %x, uid %x\n",
	538	partnumber, majrev, minrev, lot, wafer, uid);
	539
	540	data = i2c_smbus_read_byte_data(client, ABX8XX_REG_CTRL1);
	541	if (data < 0) {
	542	dev_err(&client->dev, "Unable to read control register\n");
	543	return -EIO;
	544	}
	545
	546	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CTRL1,
718a820a AB	547	((data & ~(ABX8XX_CTRL_12_24 \|
718a820a AB	548	ABX8XX_CTRL_ARST)) \|
4d61ff6b PDM	549	ABX8XX_CTRL_WRITE));
	550	if (err < 0) {
	551	dev_err(&client->dev, "Unable to write control register\n");
	552	return -EIO;
	553	}
	554
	555	/* part autodetection */
	556	if (part == ABX80X) {
	557	for (i = 0; abx80x_caps[i].pn; i++)
	558	if (partnumber == abx80x_caps[i].pn)
	559	break;
	560	if (abx80x_caps[i].pn == 0) {
	561	dev_err(&client->dev, "Unknown part: %04x\n",
	562	partnumber);
	563	return -EINVAL;
	564	}
	565	part = i;
	566	}
	567
	568	if (partnumber != abx80x_caps[part].pn) {
	569	dev_err(&client->dev, "partnumber mismatch %04x != %04x\n",
	570	partnumber, abx80x_caps[part].pn);
	571	return -EINVAL;
	572	}
	573
	574	if (np && abx80x_caps[part].has_tc)
	575	trickle_cfg = abx80x_dt_trickle_cfg(np);
	576
	577	if (trickle_cfg > 0) {
	578	dev_info(&client->dev, "Enabling trickle charger: %02x\n",
	579	trickle_cfg);
	580	abx80x_enable_trickle_charger(client, trickle_cfg);
	581	}
	582
718a820a AB	583	err = i2c_smbus_write_byte_data(client, ABX8XX_REG_CD_TIMER_CTL,
	584	BIT(2));
	585	if (err)
	586	return err;
	587
	588	rtc = devm_rtc_device_register(&client->dev, "abx8xx",
4d61ff6b PDM	589	&abx80x_rtc_ops, THIS_MODULE);
	590
	591	if (IS_ERR(rtc))
	592	return PTR_ERR(rtc);
	593
	594	i2c_set_clientdata(client, rtc);
	595
718a820a AB	596	if (client->irq > 0) {
	597	dev_info(&client->dev, "IRQ %d supplied\n", client->irq);
	598	err = devm_request_threaded_irq(&client->dev, client->irq, NULL,
	599	abx80x_handle_irq,
	600	IRQF_SHARED \| IRQF_ONESHOT,
	601	"abx8xx",
	602	client);
	603	if (err) {
	604	dev_err(&client->dev, "unable to request IRQ, alarms disabled\n");
	605	client->irq = 0;
	606	}
	607	}
	608
59a8383a MJ	609	/* Export sysfs entries */
	610	err = sysfs_create_group(&(&client->dev)->kobj, &rtc_calib_attr_group);
	611	if (err) {
	612	dev_err(&client->dev, "Failed to create sysfs group: %d\n",
	613	err);
	614	return err;
	615	}
	616
	617	err = devm_add_action(&client->dev, rtc_calib_remove_sysfs_group,
	618	&client->dev);
	619	if (err) {
	620	rtc_calib_remove_sysfs_group(&client->dev);
	621	dev_err(&client->dev,
	622	"Failed to add sysfs cleanup action: %d\n",
	623	err);
	624	return err;
	625	}
	626
4d61ff6b PDM	627	return 0;
	628	}
	629
	630	static int abx80x_remove(struct i2c_client *client)
	631	{
	632	return 0;
	633	}
	634
	635	static const struct i2c_device_id abx80x_id[] = {
	636	{ "abx80x", ABX80X },
	637	{ "ab0801", AB0801 },
	638	{ "ab0803", AB0803 },
	639	{ "ab0804", AB0804 },
	640	{ "ab0805", AB0805 },
	641	{ "ab1801", AB1801 },
	642	{ "ab1803", AB1803 },
	643	{ "ab1804", AB1804 },
	644	{ "ab1805", AB1805 },
fca733a1	645	{ "rv1805", AB1805 },
4d61ff6b PDM	646	{ }
	647	};
	648	MODULE_DEVICE_TABLE(i2c, abx80x_id);
	649
	650	static struct i2c_driver abx80x_driver = {
	651	.driver = {
	652	.name = "rtc-abx80x",
	653	},
	654	.probe = abx80x_probe,
	655	.remove = abx80x_remove,
	656	.id_table = abx80x_id,
	657	};
	658
	659	module_i2c_driver(abx80x_driver);
	660
	661	MODULE_AUTHOR("Philippe De Muyter <phdm@macqel.be>");
	662	MODULE_AUTHOR("Alexandre Belloni <alexandre.belloni@free-electrons.com>");
	663	MODULE_DESCRIPTION("Abracon ABX80X RTC driver");
	664	MODULE_LICENSE("GPL v2");