drivers/rtc/rtc-isl12022.c - kernel/msm-4.9 - Gitiles

 /*
  * An I2C driver for the Intersil ISL 12022
  *
  * Author: Roman Fietze <roman.fietze@telemotive.de>
  *
  * Based on the Philips PCF8563 RTC
  * by Alessandro Zummo <a.zummo@towertech.it>.
  *
  * 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/i2c.h>
 #include <linux/bcd.h>
 #include <linux/rtc.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include <linux/err.h>
 #include <linux/of.h>
 #include <linux/of_device.h>

 #define DRV_VERSION "0.1"

 /* ISL register offsets */
 #define ISL12022_REG_SC		0x00
 #define ISL12022_REG_MN		0x01
 #define ISL12022_REG_HR		0x02
 #define ISL12022_REG_DT		0x03
 #define ISL12022_REG_MO		0x04
 #define ISL12022_REG_YR		0x05
 #define ISL12022_REG_DW		0x06

 #define ISL12022_REG_SR		0x07
 #define ISL12022_REG_INT	0x08

 /* ISL register bits */
 #define ISL12022_HR_MIL		(1 << 7)	/* military or 24 hour time */

 #define ISL12022_SR_LBAT85	(1 << 2)
 #define ISL12022_SR_LBAT75	(1 << 1)

 #define ISL12022_INT_WRTC	(1 << 6)


 static struct i2c_driver isl12022_driver;

 struct isl12022 {
 	struct rtc_device *rtc;

 	bool write_enabled;	/* true if write enable is set */
 };


 static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
 			      uint8_t *data, size_t n)
 {
 	struct i2c_msg msgs[] = {
 		{
 			.addr	= client->addr,
 			.flags	= 0,
 			.len	= 1,
 			.buf	= data
 		},		/* setup read ptr */
 		{
 			.addr	= client->addr,
 			.flags	= I2C_M_RD,
 			.len	= n,
 			.buf	= data
 		}
 	};

 	int ret;

 	data[0] = reg;
 	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
 	if (ret != ARRAY_SIZE(msgs)) {
 		dev_err(&client->dev, "%s: read error, ret=%d\n",
 			__func__, ret);
 		return -EIO;
 	}

 	return 0;
 }


 static int isl12022_write_reg(struct i2c_client *client,
 			      uint8_t reg, uint8_t val)
 {
 	uint8_t data[2] = { reg, val };
 	int err;

 	err = i2c_master_send(client, data, sizeof(data));
 	if (err != sizeof(data)) {
 		dev_err(&client->dev,
 			"%s: err=%d addr=%02x, data=%02x\n",
 			__func__, err, data[0], data[1]);
 		return -EIO;
 	}

 	return 0;
 }


 /*
  * In the routines that deal directly with the isl12022 hardware, we use
  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
  */
 static int isl12022_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
 	uint8_t buf[ISL12022_REG_INT + 1];
 	int ret;

 	ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
 	if (ret)
 		return ret;

 	if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 | ISL12022_SR_LBAT75)) {
 		dev_warn(&client->dev,
 			 "voltage dropped below %u%%, "
 			 "date and time is not reliable.\n",
 			 buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
 	}

 	dev_dbg(&client->dev,
 		"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
 		"mday=%02x, mon=%02x, year=%02x, wday=%02x, "
 		"sr=%02x, int=%02x",
 		__func__,
 		buf[ISL12022_REG_SC],
 		buf[ISL12022_REG_MN],
 		buf[ISL12022_REG_HR],
 		buf[ISL12022_REG_DT],
 		buf[ISL12022_REG_MO],
 		buf[ISL12022_REG_YR],
 		buf[ISL12022_REG_DW],
 		buf[ISL12022_REG_SR],
 		buf[ISL12022_REG_INT]);

 	tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
 	tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
 	tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
 	tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
 	tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
 	tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
 	tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;

 	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
 		"mday=%d, mon=%d, year=%d, wday=%d\n",
 		__func__,
 		tm->tm_sec, tm->tm_min, tm->tm_hour,
 		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

 	/* The clock can give out invalid datetime, but we cannot return
 	 * -EINVAL otherwise hwclock will refuse to set the time on bootup. */
 	if (rtc_valid_tm(tm) < 0)
 		dev_err(&client->dev, "retrieved date and time is invalid.\n");

 	return 0;
 }

 static int isl12022_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
 	struct isl12022 *isl12022 = i2c_get_clientdata(client);
 	size_t i;
 	int ret;
 	uint8_t buf[ISL12022_REG_DW + 1];

 	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
 		"mday=%d, mon=%d, year=%d, wday=%d\n",
 		__func__,
 		tm->tm_sec, tm->tm_min, tm->tm_hour,
 		tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

 	if (!isl12022->write_enabled) {

 		ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
 		if (ret)
 			return ret;

 		/* Check if WRTC (write rtc enable) is set factory default is
 		 * 0 (not set) */
 		if (!(buf[0] & ISL12022_INT_WRTC)) {
 			dev_info(&client->dev,
 				 "init write enable and 24 hour format\n");

 			/* Set the write enable bit. */
 			ret = isl12022_write_reg(client,
 						 ISL12022_REG_INT,
 						 buf[0] | ISL12022_INT_WRTC);
 			if (ret)
 				return ret;

 			/* Write to any RTC register to start RTC, we use the
 			 * HR register, setting the MIL bit to use the 24 hour
 			 * format. */
 			ret = isl12022_read_regs(client, ISL12022_REG_HR,
 						 buf, 1);
 			if (ret)
 				return ret;

 			ret = isl12022_write_reg(client,
 						 ISL12022_REG_HR,
 						 buf[0] | ISL12022_HR_MIL);
 			if (ret)
 				return ret;
 		}

 		isl12022->write_enabled = 1;
 	}

 	/* hours, minutes and seconds */
 	buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
 	buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
 	buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) | ISL12022_HR_MIL;

 	buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);

 	/* month, 1 - 12 */
 	buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);

 	/* year and century */
 	buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);

 	buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;

 	/* write register's data */
 	for (i = 0; i < ARRAY_SIZE(buf); i++) {
 		ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
 					 buf[ISL12022_REG_SC + i]);
 		if (ret)
 			return -EIO;
 	}

 	return 0;
 }

 static int isl12022_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	return isl12022_get_datetime(to_i2c_client(dev), tm);
 }

 static int isl12022_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
 	return isl12022_set_datetime(to_i2c_client(dev), tm);
 }

 static const struct rtc_class_ops isl12022_rtc_ops = {
 	.read_time	= isl12022_rtc_read_time,
 	.set_time	= isl12022_rtc_set_time,
 };

 static int isl12022_probe(struct i2c_client *client,
 			  const struct i2c_device_id *id)
 {
 	struct isl12022 *isl12022;

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

 	isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
 				GFP_KERNEL);
 	if (!isl12022)
 		return -ENOMEM;

 	dev_dbg(&client->dev, "chip found, driver version " DRV_VERSION "\n");

 	i2c_set_clientdata(client, isl12022);

 	isl12022->rtc = devm_rtc_device_register(&client->dev,
 					isl12022_driver.driver.name,
 					&isl12022_rtc_ops, THIS_MODULE);
 	return PTR_ERR_OR_ZERO(isl12022->rtc);
 }

 #ifdef CONFIG_OF
 static struct of_device_id isl12022_dt_match[] = {
 	{ .compatible = "isl,isl12022" },
 	{ },
 };
 #endif

 static const struct i2c_device_id isl12022_id[] = {
 	{ "isl12022", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, isl12022_id);

 static struct i2c_driver isl12022_driver = {
 	.driver		= {
 		.name	= "rtc-isl12022",
 #ifdef CONFIG_OF
 		.of_match_table = of_match_ptr(isl12022_dt_match),
 #endif
 	},
 	.probe		= isl12022_probe,
 	.id_table	= isl12022_id,
 };

 module_i2c_driver(isl12022_driver);

 MODULE_AUTHOR("roman.fietze@telemotive.de");
 MODULE_DESCRIPTION("ISL 12022 RTC driver");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(DRV_VERSION);
	/*
	* An I2C driver for the Intersil ISL 12022
	*
	* Author: Roman Fietze <roman.fietze@telemotive.de>
	*
	* Based on the Philips PCF8563 RTC
	* by Alessandro Zummo <a.zummo@towertech.it>.
	*
	* 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/i2c.h>
	#include <linux/bcd.h>
	#include <linux/rtc.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include <linux/err.h>
	#include <linux/of.h>
	#include <linux/of_device.h>

	#define DRV_VERSION "0.1"

	/* ISL register offsets */
	#define ISL12022_REG_SC 0x00
	#define ISL12022_REG_MN 0x01
	#define ISL12022_REG_HR 0x02
	#define ISL12022_REG_DT 0x03
	#define ISL12022_REG_MO 0x04
	#define ISL12022_REG_YR 0x05
	#define ISL12022_REG_DW 0x06

	#define ISL12022_REG_SR 0x07
	#define ISL12022_REG_INT 0x08

	/* ISL register bits */
	#define ISL12022_HR_MIL (1 << 7) /* military or 24 hour time */

	#define ISL12022_SR_LBAT85 (1 << 2)
	#define ISL12022_SR_LBAT75 (1 << 1)

	#define ISL12022_INT_WRTC (1 << 6)


	static struct i2c_driver isl12022_driver;

	struct isl12022 {
	struct rtc_device *rtc;

	bool write_enabled; /* true if write enable is set */
	};


	static int isl12022_read_regs(struct i2c_client *client, uint8_t reg,
	uint8_t *data, size_t n)
	{
	struct i2c_msg msgs[] = {
	{
	.addr = client->addr,
	.flags = 0,
	.len = 1,
	.buf = data
	}, /* setup read ptr */
	{
	.addr = client->addr,
	.flags = I2C_M_RD,
	.len = n,
	.buf = data
	}
	};

	int ret;

	data[0] = reg;
	ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
	if (ret != ARRAY_SIZE(msgs)) {
	dev_err(&client->dev, "%s: read error, ret=%d\n",
	__func__, ret);
	return -EIO;
	}

	return 0;
	}


	static int isl12022_write_reg(struct i2c_client *client,
	uint8_t reg, uint8_t val)
	{
	uint8_t data[2] = { reg, val };
	int err;

	err = i2c_master_send(client, data, sizeof(data));
	if (err != sizeof(data)) {
	dev_err(&client->dev,
	"%s: err=%d addr=%02x, data=%02x\n",
	__func__, err, data[0], data[1]);
	return -EIO;
	}

	return 0;
	}


	/*
	* In the routines that deal directly with the isl12022 hardware, we use
	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
	*/
	static int isl12022_get_datetime(struct i2c_client client, struct rtc_time tm)
	{
	uint8_t buf[ISL12022_REG_INT + 1];
	int ret;

	ret = isl12022_read_regs(client, ISL12022_REG_SC, buf, sizeof(buf));
	if (ret)
	return ret;

	if (buf[ISL12022_REG_SR] & (ISL12022_SR_LBAT85 \| ISL12022_SR_LBAT75)) {
	dev_warn(&client->dev,
	"voltage dropped below %u%%, "
	"date and time is not reliable.\n",
	buf[ISL12022_REG_SR] & ISL12022_SR_LBAT85 ? 85 : 75);
	}

	dev_dbg(&client->dev,
	"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
	"mday=%02x, mon=%02x, year=%02x, wday=%02x, "
	"sr=%02x, int=%02x",
	__func__,
	buf[ISL12022_REG_SC],
	buf[ISL12022_REG_MN],
	buf[ISL12022_REG_HR],
	buf[ISL12022_REG_DT],
	buf[ISL12022_REG_MO],
	buf[ISL12022_REG_YR],
	buf[ISL12022_REG_DW],
	buf[ISL12022_REG_SR],
	buf[ISL12022_REG_INT]);

	tm->tm_sec = bcd2bin(buf[ISL12022_REG_SC] & 0x7F);
	tm->tm_min = bcd2bin(buf[ISL12022_REG_MN] & 0x7F);
	tm->tm_hour = bcd2bin(buf[ISL12022_REG_HR] & 0x3F);
	tm->tm_mday = bcd2bin(buf[ISL12022_REG_DT] & 0x3F);
	tm->tm_wday = buf[ISL12022_REG_DW] & 0x07;
	tm->tm_mon = bcd2bin(buf[ISL12022_REG_MO] & 0x1F) - 1;
	tm->tm_year = bcd2bin(buf[ISL12022_REG_YR]) + 100;

	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
	"mday=%d, mon=%d, year=%d, wday=%d\n",
	__func__,
	tm->tm_sec, tm->tm_min, tm->tm_hour,
	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

	/* The clock can give out invalid datetime, but we cannot return
	* -EINVAL otherwise hwclock will refuse to set the time on bootup. */
	if (rtc_valid_tm(tm) < 0)
	dev_err(&client->dev, "retrieved date and time is invalid.\n");

	return 0;
	}

	static int isl12022_set_datetime(struct i2c_client client, struct rtc_time tm)
	{
	struct isl12022 *isl12022 = i2c_get_clientdata(client);
	size_t i;
	int ret;
	uint8_t buf[ISL12022_REG_DW + 1];

	dev_dbg(&client->dev, "%s: secs=%d, mins=%d, hours=%d, "
	"mday=%d, mon=%d, year=%d, wday=%d\n",
	__func__,
	tm->tm_sec, tm->tm_min, tm->tm_hour,
	tm->tm_mday, tm->tm_mon, tm->tm_year, tm->tm_wday);

	if (!isl12022->write_enabled) {

	ret = isl12022_read_regs(client, ISL12022_REG_INT, buf, 1);
	if (ret)
	return ret;

	/* Check if WRTC (write rtc enable) is set factory default is
	* 0 (not set) */
	if (!(buf[0] & ISL12022_INT_WRTC)) {
	dev_info(&client->dev,
	"init write enable and 24 hour format\n");

	/* Set the write enable bit. */
	ret = isl12022_write_reg(client,
	ISL12022_REG_INT,
	buf[0] \| ISL12022_INT_WRTC);
	if (ret)
	return ret;

	/* Write to any RTC register to start RTC, we use the
	* HR register, setting the MIL bit to use the 24 hour
	* format. */
	ret = isl12022_read_regs(client, ISL12022_REG_HR,
	buf, 1);
	if (ret)
	return ret;

	ret = isl12022_write_reg(client,
	ISL12022_REG_HR,
	buf[0] \| ISL12022_HR_MIL);
	if (ret)
	return ret;
	}

	isl12022->write_enabled = 1;
	}

	/* hours, minutes and seconds */
	buf[ISL12022_REG_SC] = bin2bcd(tm->tm_sec);
	buf[ISL12022_REG_MN] = bin2bcd(tm->tm_min);
	buf[ISL12022_REG_HR] = bin2bcd(tm->tm_hour) \| ISL12022_HR_MIL;

	buf[ISL12022_REG_DT] = bin2bcd(tm->tm_mday);

	/* month, 1 - 12 */
	buf[ISL12022_REG_MO] = bin2bcd(tm->tm_mon + 1);

	/* year and century */
	buf[ISL12022_REG_YR] = bin2bcd(tm->tm_year % 100);

	buf[ISL12022_REG_DW] = tm->tm_wday & 0x07;

	/* write register's data */
	for (i = 0; i < ARRAY_SIZE(buf); i++) {
	ret = isl12022_write_reg(client, ISL12022_REG_SC + i,
	buf[ISL12022_REG_SC + i]);
	if (ret)
	return -EIO;
	}

	return 0;
	}

	static int isl12022_rtc_read_time(struct device dev, struct rtc_time tm)
	{
	return isl12022_get_datetime(to_i2c_client(dev), tm);
	}

	static int isl12022_rtc_set_time(struct device dev, struct rtc_time tm)
	{
	return isl12022_set_datetime(to_i2c_client(dev), tm);
	}

	static const struct rtc_class_ops isl12022_rtc_ops = {
	.read_time = isl12022_rtc_read_time,
	.set_time = isl12022_rtc_set_time,
	};

	static int isl12022_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct isl12022 *isl12022;

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

	isl12022 = devm_kzalloc(&client->dev, sizeof(struct isl12022),
	GFP_KERNEL);
	if (!isl12022)
	return -ENOMEM;

	dev_dbg(&client->dev, "chip found, driver version " DRV_VERSION "\n");

	i2c_set_clientdata(client, isl12022);

	isl12022->rtc = devm_rtc_device_register(&client->dev,
	isl12022_driver.driver.name,
	&isl12022_rtc_ops, THIS_MODULE);
	return PTR_ERR_OR_ZERO(isl12022->rtc);
	}

	#ifdef CONFIG_OF
	static struct of_device_id isl12022_dt_match[] = {
	{ .compatible = "isl,isl12022" },
	{ },
	};
	#endif

	static const struct i2c_device_id isl12022_id[] = {
	{ "isl12022", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, isl12022_id);

	static struct i2c_driver isl12022_driver = {
	.driver = {
	.name = "rtc-isl12022",
	#ifdef CONFIG_OF
	.of_match_table = of_match_ptr(isl12022_dt_match),
	#endif
	},
	.probe = isl12022_probe,
	.id_table = isl12022_id,
	};

	module_i2c_driver(isl12022_driver);

	MODULE_AUTHOR("roman.fietze@telemotive.de");
	MODULE_DESCRIPTION("ISL 12022 RTC driver");
	MODULE_LICENSE("GPL");
	MODULE_VERSION(DRV_VERSION);