/* * 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>#include <linux/err.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_DEVstatic 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; 	dev_dbg(&client->dev, "%s\n", __func__); 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))		return -ENODEV; 	pcf8563 = devm_kzalloc(&client->dev, 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 = devm_rtc_device_register(&client->dev,				pcf8563_driver.driver.name,				&pcf8563_rtc_ops, THIS_MODULE); 	return PTR_ERR_OR_ZERO(pcf8563->rtc);} static const struct i2c_device_id pcf8563_id[] = {	{ "pcf8563", 0 },	{ "rtc8564", 0 },	{ }};MODULE_DEVICE_TABLE(i2c, pcf8563_id); #ifdef CONFIG_OFstatic 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,	.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);