drivers/rtc/rtc-pcf8563.c - maze/linux - Git at Google

 /*
  * An I2C driver for the Philips PCF8563 RTC
  * Copyright 2005-06 Tower Technologies
  *
  * Author: Alessandro Zummo <a.zummo@towertech.it>
  * Maintainers: http://www.nslu2-linux.org/
  *
  * based on the other drivers in this same directory.
  *
  * http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
  *
  * 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/of.h>

 #define DRV_VERSION "0.4.3"

 #define PCF8563_REG_ST1		0x00 /* status */
 #define PCF8563_REG_ST2		0x01

 #define PCF8563_REG_SC		0x02 /* datetime */
 #define PCF8563_REG_MN		0x03
 #define PCF8563_REG_HR		0x04
 #define PCF8563_REG_DM		0x05
 #define PCF8563_REG_DW		0x06
 #define PCF8563_REG_MO		0x07
 #define PCF8563_REG_YR		0x08

 #define PCF8563_REG_AMN		0x09 /* alarm */
 #define PCF8563_REG_AHR		0x0A
 #define PCF8563_REG_ADM		0x0B
 #define PCF8563_REG_ADW		0x0C

 #define PCF8563_REG_CLKO	0x0D /* clock out */
 #define PCF8563_REG_TMRC	0x0E /* timer control */
 #define PCF8563_REG_TMR		0x0F /* timer */

 #define PCF8563_SC_LV		0x80 /* low voltage */
 #define PCF8563_MO_C		0x80 /* century */

 static struct i2c_driver pcf8563_driver;

 struct pcf8563 {
 	struct rtc_device *rtc;
 	/*
 	 * The meaning of MO_C bit varies by the chip type.
 	 * From PCF8563 datasheet: this bit is toggled when the years
 	 * register overflows from 99 to 00
 	 *   0 indicates the century is 20xx
 	 *   1 indicates the century is 19xx
 	 * From RTC8564 datasheet: this bit indicates change of
 	 * century. When the year digit data overflows from 99 to 00,
 	 * this bit is set. By presetting it to 0 while still in the
 	 * 20th century, it will be set in year 2000, ...
 	 * There seems no reliable way to know how the system use this
 	 * bit.  So let's do it heuristically, assuming we are live in
 	 * 1970...2069.
 	 */
 	int c_polarity;	/* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
 	int voltage_low; /* incicates if a low_voltage was detected */
 };

 /*
  * In the routines that deal directly with the pcf8563 hardware, we use
  * rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
  */
 static int pcf8563_get_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
 	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
 	unsigned char buf[13] = { PCF8563_REG_ST1 };

 	struct i2c_msg msgs[] = {
 		{/* setup read ptr */
 			.addr = client->addr,
 			.len = 1,
 			.buf = buf
 		},
 		{/* read status + date */
 			.addr = client->addr,
 			.flags = I2C_M_RD,
 			.len = 13,
 			.buf = buf
 		},
 	};

 	/* read registers */
 	if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
 		dev_err(&client->dev, "%s: read error\n", __func__);
 		return -EIO;
 	}

 	if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
 		pcf8563->voltage_low = 1;
 		dev_info(&client->dev,
 			"low voltage detected, date/time is not reliable.\n");
 	}

 	dev_dbg(&client->dev,
 		"%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
 		"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
 		__func__,
 		buf[0], buf[1], buf[2], buf[3],
 		buf[4], buf[5], buf[6], buf[7],
 		buf[8]);


 	tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
 	tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
 	tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
 	tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
 	tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
 	tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
 	tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
 	if (tm->tm_year < 70)
 		tm->tm_year += 100;	/* assume we are in 1970...2069 */
 	/* detect the polarity heuristically. see note above. */
 	pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
 		(tm->tm_year >= 100) : (tm->tm_year < 100);

 	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);

 	/* 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/time is not valid.\n");

 	return 0;
 }

 static int pcf8563_set_datetime(struct i2c_client *client, struct rtc_time *tm)
 {
 	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
 	int i, err;
 	unsigned char buf[9];

 	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[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
 	buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
 	buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);

 	buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);

 	/* month, 1 - 12 */
 	buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);

 	/* year and century */
 	buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
 	if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
 		buf[PCF8563_REG_MO] |= PCF8563_MO_C;

 	buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;

 	/* write register's data */
 	for (i = 0; i < 7; i++) {
 		unsigned char data[2] = { PCF8563_REG_SC + i,
 						buf[PCF8563_REG_SC + i] };

 		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;
 }

 #ifdef CONFIG_RTC_INTF_DEV
 static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 {
 	struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
 	struct rtc_time tm;

 	switch (cmd) {
 	case RTC_VL_READ:
 		if (pcf8563->voltage_low)
 			dev_info(dev, "low voltage detected, date/time is not reliable.\n");

 		if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
 					sizeof(int)))
 			return -EFAULT;
 		return 0;
 	case RTC_VL_CLR:
 		/*
 		 * Clear the VL bit in the seconds register in case
 		 * the time has not been set already (which would
 		 * have cleared it). This does not really matter
 		 * because of the cached voltage_low value but do it
 		 * anyway for consistency.
 		 */
 		if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
 			pcf8563_set_datetime(to_i2c_client(dev), &tm);

 		/* Clear the cached value. */
 		pcf8563->voltage_low = 0;

 		return 0;
 	default:
 		return -ENOIOCTLCMD;
 	}
 }
 #else
 #define pcf8563_rtc_ioctl NULL
 #endif

 static int pcf8563_rtc_read_time(struct device *dev, struct rtc_time *tm)
 {
 	return pcf8563_get_datetime(to_i2c_client(dev), tm);
 }

 static int pcf8563_rtc_set_time(struct device *dev, struct rtc_time *tm)
 {
 	return pcf8563_set_datetime(to_i2c_client(dev), tm);
 }

 static const struct rtc_class_ops pcf8563_rtc_ops = {
 	.ioctl		= pcf8563_rtc_ioctl,
 	.read_time	= pcf8563_rtc_read_time,
 	.set_time	= pcf8563_rtc_set_time,
 };

 static int pcf8563_probe(struct i2c_client *client,
 				const struct i2c_device_id *id)
 {
 	struct pcf8563 *pcf8563;

 	int err = 0;

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

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

 	pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL);
 	if (!pcf8563)
 		return -ENOMEM;

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

 	i2c_set_clientdata(client, pcf8563);

 	pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name,
 				&client->dev, &pcf8563_rtc_ops, THIS_MODULE);

 	if (IS_ERR(pcf8563->rtc)) {
 		err = PTR_ERR(pcf8563->rtc);
 		goto exit_kfree;
 	}

 	return 0;

 exit_kfree:
 	kfree(pcf8563);

 	return err;
 }

 static int pcf8563_remove(struct i2c_client *client)
 {
 	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);

 	if (pcf8563->rtc)
 		rtc_device_unregister(pcf8563->rtc);

 	kfree(pcf8563);

 	return 0;
 }

 static const struct i2c_device_id pcf8563_id[] = {
 	{ "pcf8563", 0 },
 	{ "rtc8564", 0 },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, pcf8563_id);

 #ifdef CONFIG_OF
 static const struct of_device_id pcf8563_of_match[] = {
 	{ .compatible = "nxp,pcf8563" },
 	{}
 };
 MODULE_DEVICE_TABLE(of, pcf8563_of_match);
 #endif

 static struct i2c_driver pcf8563_driver = {
 	.driver		= {
 		.name	= "rtc-pcf8563",
 		.owner	= THIS_MODULE,
 		.of_match_table = of_match_ptr(pcf8563_of_match),
 	},
 	.probe		= pcf8563_probe,
 	.remove		= pcf8563_remove,
 	.id_table	= pcf8563_id,
 };

 module_i2c_driver(pcf8563_driver);

 MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
 MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
 MODULE_LICENSE("GPL");
 MODULE_VERSION(DRV_VERSION);
	/*
	* An I2C driver for the Philips PCF8563 RTC
	* Copyright 2005-06 Tower Technologies
	*
	* Author: Alessandro Zummo <a.zummo@towertech.it>
	* Maintainers: http://www.nslu2-linux.org/
	*
	* based on the other drivers in this same directory.
	*
	* http://www.semiconductors.philips.com/acrobat/datasheets/PCF8563-04.pdf
	*
	* 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/of.h>

	#define DRV_VERSION "0.4.3"

	#define PCF8563_REG_ST1 0x00 /* status */
	#define PCF8563_REG_ST2 0x01

	#define PCF8563_REG_SC 0x02 /* datetime */
	#define PCF8563_REG_MN 0x03
	#define PCF8563_REG_HR 0x04
	#define PCF8563_REG_DM 0x05
	#define PCF8563_REG_DW 0x06
	#define PCF8563_REG_MO 0x07
	#define PCF8563_REG_YR 0x08

	#define PCF8563_REG_AMN 0x09 /* alarm */
	#define PCF8563_REG_AHR 0x0A
	#define PCF8563_REG_ADM 0x0B
	#define PCF8563_REG_ADW 0x0C

	#define PCF8563_REG_CLKO 0x0D /* clock out */
	#define PCF8563_REG_TMRC 0x0E /* timer control */
	#define PCF8563_REG_TMR 0x0F /* timer */

	#define PCF8563_SC_LV 0x80 /* low voltage */
	#define PCF8563_MO_C 0x80 /* century */

	static struct i2c_driver pcf8563_driver;

	struct pcf8563 {
	struct rtc_device *rtc;
	/*
	* The meaning of MO_C bit varies by the chip type.
	* From PCF8563 datasheet: this bit is toggled when the years
	* register overflows from 99 to 00
	* 0 indicates the century is 20xx
	* 1 indicates the century is 19xx
	* From RTC8564 datasheet: this bit indicates change of
	* century. When the year digit data overflows from 99 to 00,
	* this bit is set. By presetting it to 0 while still in the
	* 20th century, it will be set in year 2000, ...
	* There seems no reliable way to know how the system use this
	* bit. So let's do it heuristically, assuming we are live in
	* 1970...2069.
	*/
	int c_polarity; /* 0: MO_C=1 means 19xx, otherwise MO_C=1 means 20xx */
	int voltage_low; /* incicates if a low_voltage was detected */
	};

	/*
	* In the routines that deal directly with the pcf8563 hardware, we use
	* rtc_time -- month 0-11, hour 0-23, yr = calendar year-epoch.
	*/
	static int pcf8563_get_datetime(struct i2c_client client, struct rtc_time tm)
	{
	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
	unsigned char buf[13] = { PCF8563_REG_ST1 };

	struct i2c_msg msgs[] = {
	{/* setup read ptr */
	.addr = client->addr,
	.len = 1,
	.buf = buf
	},
	{/* read status + date */
	.addr = client->addr,
	.flags = I2C_M_RD,
	.len = 13,
	.buf = buf
	},
	};

	/* read registers */
	if ((i2c_transfer(client->adapter, msgs, 2)) != 2) {
	dev_err(&client->dev, "%s: read error\n", __func__);
	return -EIO;
	}

	if (buf[PCF8563_REG_SC] & PCF8563_SC_LV) {
	pcf8563->voltage_low = 1;
	dev_info(&client->dev,
	"low voltage detected, date/time is not reliable.\n");
	}

	dev_dbg(&client->dev,
	"%s: raw data is st1=%02x, st2=%02x, sec=%02x, min=%02x, hr=%02x, "
	"mday=%02x, wday=%02x, mon=%02x, year=%02x\n",
	__func__,
	buf[0], buf[1], buf[2], buf[3],
	buf[4], buf[5], buf[6], buf[7],
	buf[8]);


	tm->tm_sec = bcd2bin(buf[PCF8563_REG_SC] & 0x7F);
	tm->tm_min = bcd2bin(buf[PCF8563_REG_MN] & 0x7F);
	tm->tm_hour = bcd2bin(buf[PCF8563_REG_HR] & 0x3F); /* rtc hr 0-23 */
	tm->tm_mday = bcd2bin(buf[PCF8563_REG_DM] & 0x3F);
	tm->tm_wday = buf[PCF8563_REG_DW] & 0x07;
	tm->tm_mon = bcd2bin(buf[PCF8563_REG_MO] & 0x1F) - 1; /* rtc mn 1-12 */
	tm->tm_year = bcd2bin(buf[PCF8563_REG_YR]);
	if (tm->tm_year < 70)
	tm->tm_year += 100; /* assume we are in 1970...2069 */
	/* detect the polarity heuristically. see note above. */
	pcf8563->c_polarity = (buf[PCF8563_REG_MO] & PCF8563_MO_C) ?
	(tm->tm_year >= 100) : (tm->tm_year < 100);

	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);

	/* 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/time is not valid.\n");

	return 0;
	}

	static int pcf8563_set_datetime(struct i2c_client client, struct rtc_time tm)
	{
	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);
	int i, err;
	unsigned char buf[9];

	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[PCF8563_REG_SC] = bin2bcd(tm->tm_sec);
	buf[PCF8563_REG_MN] = bin2bcd(tm->tm_min);
	buf[PCF8563_REG_HR] = bin2bcd(tm->tm_hour);

	buf[PCF8563_REG_DM] = bin2bcd(tm->tm_mday);

	/* month, 1 - 12 */
	buf[PCF8563_REG_MO] = bin2bcd(tm->tm_mon + 1);

	/* year and century */
	buf[PCF8563_REG_YR] = bin2bcd(tm->tm_year % 100);
	if (pcf8563->c_polarity ? (tm->tm_year >= 100) : (tm->tm_year < 100))
	buf[PCF8563_REG_MO] \|= PCF8563_MO_C;

	buf[PCF8563_REG_DW] = tm->tm_wday & 0x07;

	/* write register's data */
	for (i = 0; i < 7; i++) {
	unsigned char data[2] = { PCF8563_REG_SC + i,
	buf[PCF8563_REG_SC + i] };

	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;
	}

	#ifdef CONFIG_RTC_INTF_DEV
	static int pcf8563_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
	{
	struct pcf8563 *pcf8563 = i2c_get_clientdata(to_i2c_client(dev));
	struct rtc_time tm;

	switch (cmd) {
	case RTC_VL_READ:
	if (pcf8563->voltage_low)
	dev_info(dev, "low voltage detected, date/time is not reliable.\n");

	if (copy_to_user((void __user *)arg, &pcf8563->voltage_low,
	sizeof(int)))
	return -EFAULT;
	return 0;
	case RTC_VL_CLR:
	/*
	* Clear the VL bit in the seconds register in case
	* the time has not been set already (which would
	* have cleared it). This does not really matter
	* because of the cached voltage_low value but do it
	* anyway for consistency.
	*/
	if (pcf8563_get_datetime(to_i2c_client(dev), &tm))
	pcf8563_set_datetime(to_i2c_client(dev), &tm);

	/* Clear the cached value. */
	pcf8563->voltage_low = 0;

	return 0;
	default:
	return -ENOIOCTLCMD;
	}
	}
	#else
	#define pcf8563_rtc_ioctl NULL
	#endif

	static int pcf8563_rtc_read_time(struct device dev, struct rtc_time tm)
	{
	return pcf8563_get_datetime(to_i2c_client(dev), tm);
	}

	static int pcf8563_rtc_set_time(struct device dev, struct rtc_time tm)
	{
	return pcf8563_set_datetime(to_i2c_client(dev), tm);
	}

	static const struct rtc_class_ops pcf8563_rtc_ops = {
	.ioctl = pcf8563_rtc_ioctl,
	.read_time = pcf8563_rtc_read_time,
	.set_time = pcf8563_rtc_set_time,
	};

	static int pcf8563_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct pcf8563 *pcf8563;

	int err = 0;

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

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

	pcf8563 = kzalloc(sizeof(struct pcf8563), GFP_KERNEL);
	if (!pcf8563)
	return -ENOMEM;

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

	i2c_set_clientdata(client, pcf8563);

	pcf8563->rtc = rtc_device_register(pcf8563_driver.driver.name,
	&client->dev, &pcf8563_rtc_ops, THIS_MODULE);

	if (IS_ERR(pcf8563->rtc)) {
	err = PTR_ERR(pcf8563->rtc);
	goto exit_kfree;
	}

	return 0;

	exit_kfree:
	kfree(pcf8563);

	return err;
	}

	static int pcf8563_remove(struct i2c_client *client)
	{
	struct pcf8563 *pcf8563 = i2c_get_clientdata(client);

	if (pcf8563->rtc)
	rtc_device_unregister(pcf8563->rtc);

	kfree(pcf8563);

	return 0;
	}

	static const struct i2c_device_id pcf8563_id[] = {
	{ "pcf8563", 0 },
	{ "rtc8564", 0 },
	{ }
	};
	MODULE_DEVICE_TABLE(i2c, pcf8563_id);

	#ifdef CONFIG_OF
	static const struct of_device_id pcf8563_of_match[] = {
	{ .compatible = "nxp,pcf8563" },
	{}
	};
	MODULE_DEVICE_TABLE(of, pcf8563_of_match);
	#endif

	static struct i2c_driver pcf8563_driver = {
	.driver = {
	.name = "rtc-pcf8563",
	.owner = THIS_MODULE,
	.of_match_table = of_match_ptr(pcf8563_of_match),
	},
	.probe = pcf8563_probe,
	.remove = pcf8563_remove,
	.id_table = pcf8563_id,
	};

	module_i2c_driver(pcf8563_driver);

	MODULE_AUTHOR("Alessandro Zummo <a.zummo@towertech.it>");
	MODULE_DESCRIPTION("Philips PCF8563/Epson RTC8564 RTC driver");
	MODULE_LICENSE("GPL");
	MODULE_VERSION(DRV_VERSION);