drivers/rtc/rtc-rx8581.c - kernel/msm-4.9 - Gitiles

 /*
  * An I2C driver for the Epson RX8581 RTC
  *
  * Author: Martyn Welch <martyn.welch@gefanuc.com>
  * Copyright 2008 GE Fanuc Intelligent Platforms Embedded Systems, Inc.
  *
  * 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.
  *
  * Based on: rtc-pcf8563.c (An I2C driver for the Philips PCF8563 RTC)
  * Copyright 2005-06 Tower Technologies
  */

 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/bcd.h>
 #include <linux/rtc.h>
 #include <linux/log2.h>

 #define DRV_VERSION "0.1"

 #define RX8581_REG_SC		0x00 /* Second in BCD */
 #define RX8581_REG_MN		0x01 /* Minute in BCD */
 #define RX8581_REG_HR		0x02 /* Hour in BCD */
 #define RX8581_REG_DW		0x03 /* Day of Week */
 #define RX8581_REG_DM		0x04 /* Day of Month in BCD */
 #define RX8581_REG_MO		0x05 /* Month in BCD */
 #define RX8581_REG_YR		0x06 /* Year in BCD */
 #define RX8581_REG_RAM		0x07 /* RAM */
 #define RX8581_REG_AMN		0x08 /* Alarm Min in BCD*/
 #define RX8581_REG_AHR		0x09 /* Alarm Hour in BCD */
 #define RX8581_REG_ADM		0x0A
 #define RX8581_REG_ADW		0x0A
 #define RX8581_REG_TMR0		0x0B
 #define RX8581_REG_TMR1		0x0C
 #define RX8581_REG_EXT		0x0D /* Extension Register */
 #define RX8581_REG_FLAG		0x0E /* Flag Register */
 #define RX8581_REG_CTRL		0x0F /* Control Register */


 /* Flag Register bit definitions */
 #define RX8581_FLAG_UF		0x20 /* Update */
 #define RX8581_FLAG_TF		0x10 /* Timer */
 #define RX8581_FLAG_AF		0x08 /* Alarm */
 #define RX8581_FLAG_VLF		0x02 /* Voltage Low */

 /* Control Register bit definitions */
 #define RX8581_CTRL_UIE		0x20 /* Update Interrupt Enable */
 #define RX8581_CTRL_TIE		0x10 /* Timer Interrupt Enable */
 #define RX8581_CTRL_AIE		0x08 /* Alarm Interrupt Enable */
 #define RX8581_CTRL_STOP	0x02 /* STOP bit */
 #define RX8581_CTRL_RESET	0x01 /* RESET bit */

 static struct i2c_driver rx8581_driver;

 /*
  * In the routines that deal directly with the rx8581 hardware, we use
  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
  */
 static int rx8581_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
 	unsigned char date[7];
 	int data, err;

 	/* First we ensure that the "update flag" is not set, we read the
 	 * time and date then re-read the "update flag". If the update flag
 	 * has been set, we know that the time has changed during the read so
 	 * we repeat the whole process again.
 	 */
 	data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
 	if (data < 0) {
 		dev_err(&client->dev, "Unable to read device flags\n");
 		return -EIO;
 	}

 	do {
 		/* If update flag set, clear it */
 		if (data & RX8581_FLAG_UF) {
 			err = i2c_smbus_write_byte_data(client,
 				RX8581_REG_FLAG, (data & ~RX8581_FLAG_UF));
 			if (err != 0) {
 				dev_err(&client->dev, "Unable to write device "
 					"flags\n");
 				return -EIO;
 			}
 		}

 		/* Now read time and date */
 		err = i2c_smbus_read_i2c_block_data(client, RX8581_REG_SC,
 			7, date);
 		if (err < 0) {
 			dev_err(&client->dev, "Unable to read date\n");
 			return -EIO;
 		}

 		/* Check flag register */
 		data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
 		if (data < 0) {
 			dev_err(&client->dev, "Unable to read device flags\n");
 			return -EIO;
 		}
 	} while (data & RX8581_FLAG_UF);

 	if (data & RX8581_FLAG_VLF)
 		dev_info(&client->dev,
 			"low voltage detected, date/time is not reliable.\n");

 	dev_dbg(&client->dev,
 		"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
 		"wday=%02x, mday=%02x, mon=%02x, year=%02x\n",
 		__func__,
 		date[0], date[1], date[2], date[3], date[4], date[5], date[6]);

 	tm->tm_sec = bcd2bin(date[RX8581_REG_SC] & 0x7F);
 	tm->tm_min = bcd2bin(date[RX8581_REG_MN] & 0x7F);
 	tm->tm_hour = bcd2bin(date[RX8581_REG_HR] & 0x3F); /* rtc hr 0-23 */
 	tm->tm_wday = ilog2(date[RX8581_REG_DW] & 0x7F);
 	tm->tm_mday = bcd2bin(date[RX8581_REG_DM] & 0x3F);
 	tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
 	tm->tm_year = bcd2bin(date[RX8581_REG_YR]);
 	if (tm->tm_year < 70)
 		tm->tm_year += 100;	/* assume we are in 1970...2069 */


 	dev_dbg(&client->dev, "%s: tm is 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);

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

 	return err;
 }

 static int rx8581_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
 	int data, err;
 	unsigned char buf[7];

 	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);

 	/* hours, minutes and seconds */
 	buf[RX8581_REG_SC] = bin2bcd(tm->tm_sec);
 	buf[RX8581_REG_MN] = bin2bcd(tm->tm_min);
 	buf[RX8581_REG_HR] = bin2bcd(tm->tm_hour);

 	buf[RX8581_REG_DM] = bin2bcd(tm->tm_mday);

 	/* month, 1 - 12 */
 	buf[RX8581_REG_MO] = bin2bcd(tm->tm_mon + 1);

 	/* year and century */
 	buf[RX8581_REG_YR] = bin2bcd(tm->tm_year % 100);
 	buf[RX8581_REG_DW] = (0x1 << tm->tm_wday);

 	/* Stop the clock */
 	data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
 	if (data < 0) {
 		dev_err(&client->dev, "Unable to read control register\n");
 		return -EIO;
 	}

 	err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG,
 		(data | RX8581_CTRL_STOP));
 	if (err < 0) {
 		dev_err(&client->dev, "Unable to write control register\n");
 		return -EIO;
 	}

 	/* write register's data */
 	err = i2c_smbus_write_i2c_block_data(client, RX8581_REG_SC, 7, buf);
 	if (err < 0) {
 		dev_err(&client->dev, "Unable to write to date registers\n");
 		return -EIO;
 	}

 	/* Restart the clock */
 	data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
 	if (data < 0) {
 		dev_err(&client->dev, "Unable to read control register\n");
 		return -EIO;
 	}

 	err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG,
 		(data | ~(RX8581_CTRL_STOP)));
 	if (err != 0) {
 		dev_err(&client->dev, "Unable to write control register\n");
 		return -EIO;
 	}

 	return 0;
 }

 static int rx8581_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	return rx8581_get_datetime(to_i2c_client(dev), tm);
 }

 static int rx8581_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
 	return rx8581_set_datetime(to_i2c_client(dev), tm);
 }

 static const struct rtc_class_ops rx8581_rtc_ops = {
 	.read_time	= rx8581_rtc_read_time,
 	.set_time	= rx8581_rtc_set_time,
 };

 static int __devinit rx8581_probe(struct i2c_client *client,
 				const struct i2c_device_id *id)
 {
 	struct rtc_device *rtc;

 	dev_dbg(&client->dev, "%s\n", __func__);

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

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

 	rtc = rtc_device_register(rx8581_driver.driver.name,
 				&client->dev, &rx8581_rtc_ops, THIS_MODULE);

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

 	i2c_set_clientdata(client, rtc);

 	return 0;
 }

 static int __devexit rx8581_remove(struct i2c_client *client)
 {
 	struct rtc_device *rtc = i2c_get_clientdata(client);

 	rtc_device_unregister(rtc);

 	return 0;
 }

 static const struct i2c_device_id rx8581_id[] = {
 	{ "rx8581", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, rx8581_id);

 static struct i2c_driver rx8581_driver = {
 	.driver		= {
 		.name	= "rtc-rx8581",
 		.owner	= THIS_MODULE,
 	},
 	.probe		= rx8581_probe,
 	.remove		= __devexit_p(rx8581_remove),
 	.id_table	= rx8581_id,
 };

 static int __init rx8581_init(void)
 {
 	return i2c_add_driver(&rx8581_driver);
 }

 static void __exit rx8581_exit(void)
 {
 	i2c_del_driver(&rx8581_driver);
 }

 MODULE_AUTHOR("Martyn Welch <martyn.welch@gefanuc.com>");
 MODULE_DESCRIPTION("Epson RX-8581 RTC driver");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(DRV_VERSION);

 module_init(rx8581_init);
 module_exit(rx8581_exit);
	/*
	* An I2C driver for the Epson RX8581 RTC
	*
	* Author: Martyn Welch <martyn.welch@gefanuc.com>
	* Copyright 2008 GE Fanuc Intelligent Platforms Embedded Systems, Inc.
	*
	* 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.
	*
	* Based on: rtc-pcf8563.c (An I2C driver for the Philips PCF8563 RTC)
	* Copyright 2005-06 Tower Technologies
	*/

	#include <linux/module.h>
	#include <linux/i2c.h>
	#include <linux/bcd.h>
	#include <linux/rtc.h>
	#include <linux/log2.h>

	#define DRV_VERSION "0.1"

	#define RX8581_REG_SC 0x00 /* Second in BCD */
	#define RX8581_REG_MN 0x01 /* Minute in BCD */
	#define RX8581_REG_HR 0x02 /* Hour in BCD */
	#define RX8581_REG_DW 0x03 /* Day of Week */
	#define RX8581_REG_DM 0x04 /* Day of Month in BCD */
	#define RX8581_REG_MO 0x05 /* Month in BCD */
	#define RX8581_REG_YR 0x06 /* Year in BCD */
	#define RX8581_REG_RAM 0x07 /* RAM */
	#define RX8581_REG_AMN 0x08 /* Alarm Min in BCD*/
	#define RX8581_REG_AHR 0x09 /* Alarm Hour in BCD */
	#define RX8581_REG_ADM 0x0A
	#define RX8581_REG_ADW 0x0A
	#define RX8581_REG_TMR0 0x0B
	#define RX8581_REG_TMR1 0x0C
	#define RX8581_REG_EXT 0x0D /* Extension Register */
	#define RX8581_REG_FLAG 0x0E /* Flag Register */
	#define RX8581_REG_CTRL 0x0F /* Control Register */


	/* Flag Register bit definitions */
	#define RX8581_FLAG_UF 0x20 /* Update */
	#define RX8581_FLAG_TF 0x10 /* Timer */
	#define RX8581_FLAG_AF 0x08 /* Alarm */
	#define RX8581_FLAG_VLF 0x02 /* Voltage Low */

	/* Control Register bit definitions */
	#define RX8581_CTRL_UIE 0x20 /* Update Interrupt Enable */
	#define RX8581_CTRL_TIE 0x10 /* Timer Interrupt Enable */
	#define RX8581_CTRL_AIE 0x08 /* Alarm Interrupt Enable */
	#define RX8581_CTRL_STOP 0x02 /* STOP bit */
	#define RX8581_CTRL_RESET 0x01 /* RESET bit */

	static struct i2c_driver rx8581_driver;

	/*
	* In the routines that deal directly with the rx8581 hardware, we use
	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
	*/
	static int rx8581_get_datetime(struct i2c_client client, struct rtc_time tm)
	{
	unsigned char date[7];
	int data, err;

	/* First we ensure that the "update flag" is not set, we read the
	* time and date then re-read the "update flag". If the update flag
	* has been set, we know that the time has changed during the read so
	* we repeat the whole process again.
	*/
	data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
	if (data < 0) {
	dev_err(&client->dev, "Unable to read device flags\n");
	return -EIO;
	}

	do {
	/* If update flag set, clear it */
	if (data & RX8581_FLAG_UF) {
	err = i2c_smbus_write_byte_data(client,
	RX8581_REG_FLAG, (data & ~RX8581_FLAG_UF));
	if (err != 0) {
	dev_err(&client->dev, "Unable to write device "
	"flags\n");
	return -EIO;
	}
	}

	/* Now read time and date */
	err = i2c_smbus_read_i2c_block_data(client, RX8581_REG_SC,
	7, date);
	if (err < 0) {
	dev_err(&client->dev, "Unable to read date\n");
	return -EIO;
	}

	/* Check flag register */
	data = i2c_smbus_read_byte_data(client, RX8581_REG_FLAG);
	if (data < 0) {
	dev_err(&client->dev, "Unable to read device flags\n");
	return -EIO;
	}
	} while (data & RX8581_FLAG_UF);

	if (data & RX8581_FLAG_VLF)
	dev_info(&client->dev,
	"low voltage detected, date/time is not reliable.\n");

	dev_dbg(&client->dev,
	"%s: raw data is sec=%02x, min=%02x, hr=%02x, "
	"wday=%02x, mday=%02x, mon=%02x, year=%02x\n",
	__func__,
	date[0], date[1], date[2], date[3], date[4], date[5], date[6]);

	tm->tm_sec = bcd2bin(date[RX8581_REG_SC] & 0x7F);
	tm->tm_min = bcd2bin(date[RX8581_REG_MN] & 0x7F);
	tm->tm_hour = bcd2bin(date[RX8581_REG_HR] & 0x3F); /* rtc hr 0-23 */
	tm->tm_wday = ilog2(date[RX8581_REG_DW] & 0x7F);
	tm->tm_mday = bcd2bin(date[RX8581_REG_DM] & 0x3F);
	tm->tm_mon = bcd2bin(date[RX8581_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
	tm->tm_year = bcd2bin(date[RX8581_REG_YR]);
	if (tm->tm_year < 70)
	tm->tm_year += 100; /* assume we are in 1970...2069 */


	dev_dbg(&client->dev, "%s: tm is 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);

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

	return err;
	}

	static int rx8581_set_datetime(struct i2c_client client, struct rtc_time tm)
	{
	int data, err;
	unsigned char buf[7];

	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);

	/* hours, minutes and seconds */
	buf[RX8581_REG_SC] = bin2bcd(tm->tm_sec);
	buf[RX8581_REG_MN] = bin2bcd(tm->tm_min);
	buf[RX8581_REG_HR] = bin2bcd(tm->tm_hour);

	buf[RX8581_REG_DM] = bin2bcd(tm->tm_mday);

	/* month, 1 - 12 */
	buf[RX8581_REG_MO] = bin2bcd(tm->tm_mon + 1);

	/* year and century */
	buf[RX8581_REG_YR] = bin2bcd(tm->tm_year % 100);
	buf[RX8581_REG_DW] = (0x1 << tm->tm_wday);

	/* Stop the clock */
	data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
	if (data < 0) {
	dev_err(&client->dev, "Unable to read control register\n");
	return -EIO;
	}

	err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG,
	(data \| RX8581_CTRL_STOP));
	if (err < 0) {
	dev_err(&client->dev, "Unable to write control register\n");
	return -EIO;
	}

	/* write register's data */
	err = i2c_smbus_write_i2c_block_data(client, RX8581_REG_SC, 7, buf);
	if (err < 0) {
	dev_err(&client->dev, "Unable to write to date registers\n");
	return -EIO;
	}

	/* Restart the clock */
	data = i2c_smbus_read_byte_data(client, RX8581_REG_CTRL);
	if (data < 0) {
	dev_err(&client->dev, "Unable to read control register\n");
	return -EIO;
	}

	err = i2c_smbus_write_byte_data(client, RX8581_REG_FLAG,
	(data \| ~(RX8581_CTRL_STOP)));
	if (err != 0) {
	dev_err(&client->dev, "Unable to write control register\n");
	return -EIO;
	}

	return 0;
	}

	static int rx8581_rtc_read_time(struct device dev, struct rtc_time tm)
	{
	return rx8581_get_datetime(to_i2c_client(dev), tm);
	}

	static int rx8581_rtc_set_time(struct device dev, struct rtc_time tm)
	{
	return rx8581_set_datetime(to_i2c_client(dev), tm);
	}

	static const struct rtc_class_ops rx8581_rtc_ops = {
	.read_time = rx8581_rtc_read_time,
	.set_time = rx8581_rtc_set_time,
	};

	static int __devinit rx8581_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct rtc_device *rtc;

	dev_dbg(&client->dev, "%s\n", __func__);

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

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

	rtc = rtc_device_register(rx8581_driver.driver.name,
	&client->dev, &rx8581_rtc_ops, THIS_MODULE);

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

	i2c_set_clientdata(client, rtc);

	return 0;
	}

	static int __devexit rx8581_remove(struct i2c_client *client)
	{
	struct rtc_device *rtc = i2c_get_clientdata(client);

	rtc_device_unregister(rtc);

	return 0;
	}

	static const struct i2c_device_id rx8581_id[] = {
	{ "rx8581", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, rx8581_id);

	static struct i2c_driver rx8581_driver = {
	.driver = {
	.name = "rtc-rx8581",
	.owner = THIS_MODULE,
	},
	.probe = rx8581_probe,
	.remove = __devexit_p(rx8581_remove),
	.id_table = rx8581_id,
	};

	static int __init rx8581_init(void)
	{
	return i2c_add_driver(&rx8581_driver);
	}

	static void __exit rx8581_exit(void)
	{
	i2c_del_driver(&rx8581_driver);
	}

	MODULE_AUTHOR("Martyn Welch <martyn.welch@gefanuc.com>");
	MODULE_DESCRIPTION("Epson RX-8581 RTC driver");
	MODULE_LICENSE("GPL");
	MODULE_VERSION(DRV_VERSION);

	module_init(rx8581_init);
	module_exit(rx8581_exit);